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Sample records for lns burner employs

  1. Low NO sub x /SO sub x Burner retrofit for utility cyclone boilers

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    This Public Design Report provides available nonproprietary design information on the Low NO{sub x}SO{sub x} Burner Retrofit of Utility Cyclone Boilers project. In addition to the design aspects, the history of the project, the organization of the project, and the role of the funding parties are discussed. An overview of the Low NO{sub x}SO{sub x} (LNS) Burner, the cyclone boiler and the Southern Illinois Power Cooperative host site is presented. A detailed nonproprietary description of the individual process steps, plant systems, and resulting performance then follows. Narrative process descriptions, simplified process flow diagrams, input/output stream data, operating conditions and requirements are given for each unit. The plant demonstration program and start up provisions, the environmental considerations and control, monitoring and safety factors that are considered are also addressed.

  2. Low NO{sub x}/SO{sub x} Burner retrofit for utility cyclone boilers. Public design report

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    This Public Design Report provides available nonproprietary design information on the Low NO{sub x}SO{sub x} Burner Retrofit of Utility Cyclone Boilers project. In addition to the design aspects, the history of the project, the organization of the project, and the role of the funding parties are discussed. An overview of the Low NO{sub x}SO{sub x} (LNS) Burner, the cyclone boiler and the Southern Illinois Power Cooperative host site is presented. A detailed nonproprietary description of the individual process steps, plant systems, and resulting performance then follows. Narrative process descriptions, simplified process flow diagrams, input/output stream data, operating conditions and requirements are given for each unit. The plant demonstration program and start up provisions, the environmental considerations and control, monitoring and safety factors that are considered are also addressed.

  3. Burners and combustion apparatus for carbon nanomaterial production

    Science.gov (United States)

    Alford, J. Michael; Diener, Michael D; Nabity, James; Karpuk, Michael

    2013-02-05

    The invention provides improved burners, combustion apparatus, and methods for carbon nanomaterial production. The burners of the invention provide sooting flames of fuel and oxidizing gases. The condensable products of combustion produced by the burners of this invention produce carbon nanomaterials including without limitation, soot, fullerenic soot, and fullerenes. The burners of the invention do not require premixing of the fuel and oxidizing gases and are suitable for use with low vapor pressure fuels such as those containing substantial amounts of polyaromatic hydrocarbons. The burners of the invention can operate with a hot (e.g., uncooled) burner surface and require little, if any, cooling or other forms of heat sinking. The burners of the invention comprise one or more refractory elements forming the outlet of the burner at which a flame can be established. The burners of the invention provide for improved flame stability, can be employed with a wider range of fuel/oxidizer (e.g., air) ratios and a wider range of gas velocities, and are generally more efficient than burners using water-cooled metal burner plates. The burners of the invention can also be operated to reduce the formation of undesirable soot deposits on the burner and on surfaces downstream of the burner.

  4. Methane combustion in catalytic premixed burners

    International Nuclear Information System (INIS)

    Cerri, I.; Saracco, G.; Specchia, V.

    1999-01-01

    Catalytic premixed burners for domestic boiler applications were developed with the aim of achieving a power modularity from 10 to 100% and pollutant emissions limited to NO x 2 , where the combustion took place entirely inside the burner heating it to incandescence and allowing a decrease in the flame temperature and NO x emissions. Such results were confirmed through further tests carried out in a commercial industrial-scale boiler equipped with the conical panels. All the results, by varying the excess air and the heat power employed, are presented and discussed [it

  5. 0.20-m (8-in.) primary burner development report

    International Nuclear Information System (INIS)

    Stula, R.T.; Young, D.T.; Rode, J.S.

    1977-12-01

    High-Temperature Gas-Cooled Reactors (HTGRs) utilize graphite-base fuels. Fluidized-bed burners are being employed successfully in the experimental reprocessing of these fuels. The primary fluidized-bed burner is a unit operation in the reprocessing flowsheet in which the graphite moderator is removed. A detailed description of the development status of the 0.20-m (8-in.) diameter primary fluidized-bed burner as of July 1, 1977 is presented. Experimental work to date performed in 0.10; 0.20; and 0.40-m (4, 8, and 16 in.) diameter primary burners has demonstrated the feasibility of the primary burning process and, at the same time, has defined more clearly the areas in which additional experimental work is required. The design and recent operating history of the 0.20-m-diameter burner are discussed, with emphasis placed upon the evolution of the current design and operating philosophy

  6. Status and Perspectives of the INFN-LNS In-Flight Fragment Separator

    Science.gov (United States)

    Russotto, P.; Calabretta, L.; Cardella, G.; Cosentino, G.; De Filippo, E.; Gnoffo, B.; La Cognata, M.; Martorana, N. S.; Pagano, E. V.; Pizzone, R. G.; Quattrocchi, L.; Romano, S.; Russo, A. D.; Santonocito, D.

    2018-05-01

    In the last 15 years the FRIBs@LNS facility has successfully produced Radioactive Ion Beams using the In-Flight technique. We report on the current status and future perspectives opened by FRAISE, a new fragment separator that will be build in connection with the upgrade of Superconducting Cyclotron of the INFN-LNS laboratories.

  7. Physicochemical characterization of epigallocatechin gallate lipid nanoparticles (EGCG-LNs) for ocular instillation.

    Science.gov (United States)

    Fangueiro, Joana F; Andreani, Tatiana; Fernandes, Lisete; Garcia, Maria L; Egea, Maria A; Silva, Amélia M; Souto, Eliana B

    2014-11-01

    The encapsulation of epigallocatechin gallate (EGCG) in lipid nanoparticles (LNs) could be a suitable approach to avoid drug oxidation and epimerization, which are common processes that lead to low bioavailability of the drug limiting its therapeutic efficacy. The human health benefits of EGCG gained much interest in the pharmaceutical field, and so far there are no studies reporting its encapsulation in LNs. The purpose of this study has been the development of an innovative system for the ocular delivery of EGCG using LNs as carrier for the future treatment of several diseases, such as dry eye, age-related macular degeneration (AMD), glaucoma, diabetic retinopathy and macular oedema. LNs dispersions have been produced by multiple emulsion technique and previously optimized by a factorial design. In order to increase ocular retention time and mucoadhesion by electrostatic attraction, two distinct cationic lipids were used, namely, cetyltrimethylammonium bromide (CTAB) and dimethyldioctadecylammonium bromide (DDAB). EGCG has been successfully loaded in the LNs dispersions and the nanoparticles analysis over 30 days of storage time predicted a good physicochemical stability. The particles were found to be in the nanometer range (<300 nm) and all the evaluated parameters, namely pH, osmolarity and viscosity, were compatible to the ocular administration. The evaluation of the cationic lipid used was compared regarding physical and chemical parameters, lipid crystallization and polymorphism, and stability of dispersion during storage. The results show that different lipids lead to different characteristics mainly associated with the acyl chain composition, i.e. double lipid shows to have influence in the crystallization and stability. Despite the recorded differences between DTAB and DDAB, both cationic LNs seem to fit the parameters for ocular drug delivery. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Preventative lipid-based nutrient supplements (LNS) and young child feeding practices: findings from qualitative research in Haiti.

    Science.gov (United States)

    Lesorogol, Carolyn; Jean-Louis, Sherlie; Green, Jamie; Iannotti, Lora

    2015-12-01

    To prevent undernutrition in an urban slum in Haiti, a lipid-based nutrient supplement (LNS) was introduced through a randomised control trial. Food supplementation for young child nutrition has a long history in Haiti, but there is little empirical information regarding the effects of supplementation on young child feeding practices. One of the concerns raised by supplementation is that it may disrupt other positive feeding practices such as breastfeeding and use of other complementary foods, with negative consequences for child nutrition. We conducted 29 in-depth interviews with mother-baby pairs from the three comparison groups: control, 3-month LNS supplementation and 6-month LNS supplementation. Findings from those in the LNS groups indicated high acceptance and satisfaction with LNS and perceptions that it positively affects child health and development. LNS was integrated into and enhanced ongoing complementary feeding practices. The effects of LNS use on duration and perceived quantity of breastfeeding were variable, but generally, breastfeeding was maintained during and after the intervention. Interviews generated insights into beliefs regarding infant and young child feeding practices such as introduction and use of complementary foods, and breastfeeding duration, exclusivity and cessation. Implications for the use of LNS in public health nutrition programmes are discussed. © 2014 John Wiley & Sons Ltd.

  9. Experimental investigations and numerical simulations of methane cup-burner flame

    Directory of Open Access Journals (Sweden)

    Kubát P.

    2013-04-01

    Full Text Available Pulsation frequency of the cup-burner flame was determined by means of experimental investigations and numerical simulations. Simplified chemical kinetics was successfully implemented into a laminar fluid flow model applied to the complex burner geometry. Our methodical approach is based on the monitoring of flame emission, fast Fourier transformation and reproduction of measured spectral features by numerical simulations. Qualitative agreement between experimental and predicted oscillatory behaviour was obtained by employing a two-step methane oxidation scheme.

  10. Pulverized coal burner

    Science.gov (United States)

    Sivy, J.L.; Rodgers, L.W.; Koslosy, J.V.; LaRue, A.D.; Kaufman, K.C.; Sarv, H.

    1998-11-03

    A burner is described having lower emissions and lower unburned fuel losses by implementing a transition zone in a low NO{sub x} burner. The improved burner includes a pulverized fuel transport nozzle surrounded by the transition zone which shields the central oxygen-lean fuel devolatilization zone from the swirling secondary combustion air. The transition zone acts as a buffer between the primary and the secondary air streams to improve the control of near-burner mixing and flame stability by providing limited recirculation regions between primary and secondary air streams. These limited recirculation regions transport evolved NO{sub x} back towards the oxygen-lean fuel pyrolysis zone for reduction to molecular nitrogen. Alternate embodiments include natural gas and fuel oil firing. 8 figs.

  11. Status of the EXCYT facility at INFN-LNS

    Energy Technology Data Exchange (ETDEWEB)

    Ciavola, G. E-mail: ciavola@lns.infn.it; Alba, R.; Calabretta, L.; Celona, L.; Cosentino, G.; Cuttone, G.; Finocchiaro, P.; Gammino, S.; Menna, M.; Papaleo, R.; Raia, G.; Rifuggiato, D.; Rovelli, A.; Silvestri, M.; Vinciguerra, D.; Winkler, M

    2002-04-22

    The EXCYT facility at the INFN-LNS aims to the production of radioactive ion beams to be post-accelerated by a 15 MV Tandem. The primary stable heavy-ion beam (up to 80 MeV/amu, 1 p{mu}A) is supplied by a K-800 Superconducting Cyclotron, which has been operating in a stand-alone mode, by means of the new axial injection beam line, since December, 1999. The magnets of the primary beam line have been aligned and most of the components of the mass separator have been purchased. Different types of Heavy Ion Target-Source (HITS) systems have been built and are here described; in particular, a microwave ion source fully designed and manufactured at LNS has been assembled and successfully tested. Finally, low-intensity beam diagnostics is also ready and reliability tests are under way.

  12. Status of the EXCYT facility at INFN-LNS

    International Nuclear Information System (INIS)

    Ciavola, G.; Alba, R.; Calabretta, L.; Celona, L.; Cosentino, G.; Cuttone, G.; Finocchiaro, P.; Gammino, S.; Menna, M.; Papaleo, R.; Raia, G.; Rifuggiato, D.; Rovelli, A.; Silvestri, M.; Vinciguerra, D.; Winkler, M.

    2002-01-01

    The EXCYT facility at the INFN-LNS aims to the production of radioactive ion beams to be post-accelerated by a 15 MV Tandem. The primary stable heavy-ion beam (up to 80 MeV/amu, 1 pμA) is supplied by a K-800 Superconducting Cyclotron, which has been operating in a stand-alone mode, by means of the new axial injection beam line, since December, 1999. The magnets of the primary beam line have been aligned and most of the components of the mass separator have been purchased. Different types of Heavy Ion Target-Source (HITS) systems have been built and are here described; in particular, a microwave ion source fully designed and manufactured at LNS has been assembled and successfully tested. Finally, low-intensity beam diagnostics is also ready and reliability tests are under way

  13. Ammonia-methane combustion in tangential swirl burners for gas turbine power generation

    OpenAIRE

    Valera Medina, Agustin; Marsh, Richard; Runyon, Jon; Pugh, Daniel; Beasley, Paul; Hughes, Timothy Richard; Bowen, Philip John

    2017-01-01

    Ammonia has been proposed as a potential energy storage medium in the transition towards a low-carbon economy. This paper details experimental results and numerical calculations obtained to progress towards optimisation of fuel injection and fluidic stabilisation in swirl burners with ammonia as the primary fuel. A generic tangential swirl burner has been employed to determine flame stability and emissions produced at different equivalence ratios using ammonia–methane blends. Experiments were...

  14. High conversion burner type reactor

    International Nuclear Information System (INIS)

    Higuchi, Shin-ichi; Kawashima, Masatoshi

    1987-01-01

    Purpose: To simply and easily dismantle and reassemble densified fuel assemblies taken out of a high conversion ratio area thereby improve the neutron and fuel economy. Constitution: The burner portion for the purpose of fuel combustion is divided into a first burner region in adjacent with the high conversion ratio area at the center of the reactor core, and a second burner region formed to the outer circumference thereof and two types of fuels are charged therein. Densified fuel assemblies charged in the high conversion ratio area are separatably formed as fuel assemblies for use in the two types of burners. In this way, dense fuel assembly is separated into two types of fuel assemblies for use in burner of different number and arranging density of fuel elements which can be directly charged to the burner portion and facilitate the dismantling and reassembling of the fuel assemblies. Further, since the two types of fuel assemblies are charged in the burner portion, utilization factor for the neutron fuels can be improved. (Kamimura, M.)

  15. lns physics, knowledge and problems

    International Nuclear Information System (INIS)

    Jacob, M.

    1976-01-01

    Reference is made to recent experimentation at the CERN intersecting storage ring (ISR) and experimentation at Fermilab. This is stated to have opened up a wide new domain as regards energy considerations. The ISR spans the 250 to 2000 GeV domain, whereas the Fermilab facilities reach 500 GeV. The many processes already studied are stated to show strikingly different energy behaviour. These commands do not attempt any systematic review of lns physics, but emphasise only a few important facts and questions. Three topics considered are (i) rising cross sections and related phenomena, (ii) scaling and short range order; and (iii) inelastic diffractive phenomena. Regarding (i) it is stated that all phenomena directly related to rising cross sections are amenable to simple logarithmic parametrisations that fit well with what is expected for very high energy behaviour. The very slow pace at which this occurs, however, remains a puzzle. With regard to (ii) the impressive stability of the phase space configuration of multiparticle events is stressed, which is translated in practice by scaling and short range order. Regarding (iii) diffractive excitation is an important topic in high energy hadron physics, and double diffractive excitation is an interesting study. It is stated that the stability of all large cross section hadronic processes with increasing energy is remarkable, and it is not understood why so many things change so slowly with increasing energy. What can be referred to as lns physics still carries many challenging questions. (U.K.)

  16. Recent improvements of the tandem facility at LNS

    International Nuclear Information System (INIS)

    Ciavola, G.; Calabretta, L.; Cuttone, G.; Gammino, S.; Raia, G.; Rifuggiato, D.; Rovelli, A.; Scuderi, V.

    1993-01-01

    The Laboratorio Nazionale del Sud (LNS) of Catania is equipped with an upgraded 15 MV SMP tandem that is going to be coupled to a k=800 superconducting cyclotron. The status of the facility and the performances of the upgraded tandem are presented. (orig.)

  17. FIELD EVALUATION OF LOW-EMISSION COAL BURNER TECHNOLOGY ON UTILITY BOILERS VOLUME II. SECOND GENERATION LOW-NOX BURNERS

    Science.gov (United States)

    The report describes tests to evaluate the performance characteristics of three Second Generation Low-NOx burner designs: the Dual Register burner (DRB), the Babcock-Hitachi NOx Reducing (HNR) burner, and the XCL burner. The three represent a progression in development based on t...

  18. Radial lean direct injection burner

    Science.gov (United States)

    Khan, Abdul Rafey; Kraemer, Gilbert Otto; Stevenson, Christian Xavier

    2012-09-04

    A burner for use in a gas turbine engine includes a burner tube having an inlet end and an outlet end; a plurality of air passages extending axially in the burner tube configured to convey air flows from the inlet end to the outlet end; a plurality of fuel passages extending axially along the burner tube and spaced around the plurality of air passage configured to convey fuel from the inlet end to the outlet end; and a radial air swirler provided at the outlet end configured to direct the air flows radially toward the outlet end and impart swirl to the air flows. The radial air swirler includes a plurality of vanes to direct and swirl the air flows and an end plate. The end plate includes a plurality of fuel injection holes to inject the fuel radially into the swirling air flows. A method of mixing air and fuel in a burner of a gas turbine is also provided. The burner includes a burner tube including an inlet end, an outlet end, a plurality of axial air passages, and a plurality of axial fuel passages. The method includes introducing an air flow into the air passages at the inlet end; introducing a fuel into fuel passages; swirling the air flow at the outlet end; and radially injecting the fuel into the swirling air flow.

  19. Using CHIMERA detector at LNS for gamma-particle coincidences

    Directory of Open Access Journals (Sweden)

    Cardella G.

    2016-01-01

    Full Text Available We have recently evaluated the quality of γ-ray angular distributions that can be extracted in particle-gamma coincidence measurements using the CHIMERA detector at LNS. γ-rays have been detected using the CsI(Tl detectors of the spherical part of the CHIMERA array. Very clean γ-rays angular distributions were extracted in reactions induced by different stable beams impinging on 12C thin targets. The results evidenced an effect of projectile spin flip on the γ-rays angular distributions. γ-particle coincidence measurements were also performed in reactions induced by neutron rich exotic beams produced through in-flight fragmentation at LNS. In recent experiments also the Farcos array was used to improve energy and angular resolution measurements of the detected charged particles. Results obtained with both stable and radioactive beams are reported.

  20. Radioactive ion beam facilities at INFN LNS

    International Nuclear Information System (INIS)

    Rifuggiato, D; Calabretta, L; Celona, L; Chines, F; Cosentino, L; Cuttone, G; Finocchiaro, P; Pappalardo, A; Re, M; Rovelli, A

    2011-01-01

    Radioactive ion beams are produced at INFN- Laboratori Nazionali del Sud (LNS) by means of the two operating accelerators, the Tandem and the Superconducting Cyclotron (CS), originally designed to accelerate stable beams. Both the ISOL (Isotope Separation On Line) and the IFF (In-Flight Fragmentation) methods are exploited to produce RIBs in two different ways at different energies: in the first case, the Cyclotron is the primary accelerator and the Tandem accelerates the secondary beams, while in the second case radioactive fragments are produced by the Cyclotron beam in a thin target with energies comparable to the primary beam energy. The ISOL facility is named EXCYT (Exotics at the Cyclotron and Tandem) and was commissioned in 2006, when the first radioactive beam ( 8 Li) has been produced. The IFF installation is named FRIBs (in Flight Radioactive Ion Beams), and it has started to produce radioactive beams in 2001, placing a thin target in the extraction beam line of the Cyclotron. The development of both facilities to produce and accelerate radioactive ion beams at LNS, is briefly described, with some details on the future prospects that are presently under consideration or realization.

  1. LOW NOX BURNER DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    KRISHNA,C.R.; BUTCHER,T.

    2004-09-30

    The objective of the task is to develop concepts for ultra low NOx burners. One approach that has been tested previously uses internal recirculation of hot gases and the objective was to how to implement variable recirculation rates during burner operation. The second approach was to use fuel oil aerosolization (vaporization) and combustion in a porous medium in a manner similar to gas-fired radiant burners. This task is trying the second approach with the use of a somewhat novel, prototype system for aerosolization of the liquid fuel.

  2. Industrial burner and process efficiency program

    Science.gov (United States)

    Huebner, S. R.; Prakash, S. N.; Hersh, D. B.

    1982-10-01

    There is an acute need for a burner that does not use excess air to provide the required thermal turndown and internal recirculation of furnace gases in direct fired batch type furnaces. Such a burner would improve fuel efficiency and product temperature uniformity. A high velocity burner has been developed which is capable of multi-fuel, preheated air, staged combustion. This burner is operated by a microprocessor to fire in a discrete pulse mode using Frequency Modulation (FM) for furnace temperature control by regulating the pulse duration. A flame safety system has been designed to monitor the pulse firing burners using Factory Mutual approved components. The FM combustion system has been applied to an industrial batch hardening furnace (1800 F maximum temperature, 2500 lbs load capacity).

  3. Numerical simulation of porous burners and hole plate surface burners

    Directory of Open Access Journals (Sweden)

    Nemoda Stevan

    2004-01-01

    Full Text Available In comparison to the free flame burners the porous medium burners, especially those with flame stabilization within the porous material, are characterized by a reduction of the combustion zone temperatures and high combustion efficiency, so that emissions of pollutants are minimized. In the paper the finite-volume numerical tool for calculations of the non-isothermal laminar steady-state flow, with chemical reactions in laminar gas flow as well as within porous media is presented. For the porous regions the momentum and energy equations have appropriate corrections. In the momentum equations for the porous region an additional pressure drop has to be considered, which depends on the properties of the porous medium. For the heat transfer within the porous matrix description a heterogeneous model is considered. It treats the solid and gas phase separately, but the phases are coupled via a convective heat exchange term. For the modeling of the reaction of the methane laminar combustion the chemical reaction scheme with 164 reactions and 20 chemical species was used. The proposed numerical tool is applied for the analyses of the combustion and heat transfer processes which take place in porous and surface burners. The numerical experiments are accomplished for different powers of the porous and surface burners, as well as for different heat conductivity character is tics of the porous regions.

  4. Use of fragmentation beams at LNS with CHIMERA detector

    Directory of Open Access Journals (Sweden)

    Gianí R.

    2012-07-01

    Full Text Available The recent intensity upgrade of the LNS fragmentation beam is discussed. The available beams, the tagging procedures and details on the beam quality are reported. The experimental program started with the CHIMERA detector using such beams is also discussed with preliminary results and future perspectives.

  5. Optimization of burners in oxygen-gas fired glass furnace

    NARCIS (Netherlands)

    Kersbergen, M.J. van; Beerkens, R.G.C.; Sarmiento-Darkin, W.; Kobayashi, H.

    2012-01-01

    The energy efficiency performance, production stability and emissions of oxygen-fired glass furnaces are influenced by the type of burner, burner nozzle sizes, burner positions, burner settings, oxygen-gas ratios and the fuel distribution among all the burners. These parameters have been optimized

  6. Southern Woods-Burners: A Descriptive Analysis

    Science.gov (United States)

    M.L. Doolittle; M.L. Lightsey

    1979-01-01

    About 40 percent of the South's nearly 60,000 wildfires yearly are set by woods-burners. A survey of 14 problem areas in four southern States found three distinct sets of woods-burners. Most active woods-burners are young, white males whose activities are supported by their peers. An older but less active group have probably retired from active participation but...

  7. Status Of The EXCYT Facility at INFN-LNS

    International Nuclear Information System (INIS)

    Cuttone, G.; Alba, R.; Calabretta, L.; Celona, L.; Chines, F.; Cosentino, L.; Finocchiaro, P.; Grmek, A.; Gammino, S.; Menna, M.; Messina, G.E.; Raia, G.; Passarello, S.; Re, M.; Rifuggiato, D.; Rovelli, A.; Russo, S.; Schillaci, G.; Scuderi, V.; Zappala, E.

    2004-01-01

    The EXCYT facility (EXotics with CYclotron and Tandem) at the INFN-LNS is based on a K-800 Superconducting Cyclotron injecting stable heavy-ion beams (up to 80 MeV/amu, 1 eμA) into a target-ion source assembly to produce the required nuclear species, and on a 15 MV Tandem for post-accelerating the radioactive beams. Since December 1999 the Superconducting Cyclotron operates in a stand-alone mode by means of the new axial injection beam line. The primary beam line has been already mounted and tested. The part of mass separator on the two high-voltage platforms together with low intensity diagnostics is already installed while the ancillary items along with the part of mass separator at ground potential will be installed during the next stop of accelerator operations. The target-ion source unit has been successfully tested on-line at GANIL. The goal of such efforts will be represented by the test of the mass separator with stable beams planned at LNS by the end of the year. The commissioning of the EXCYT facility is foreseen in 2004 together with the start of nuclear experiments program

  8. Case study for co and counter swirling domestic burners

    Directory of Open Access Journals (Sweden)

    Ashraf Kotb

    2018-03-01

    Full Text Available In this case study, the influence of equivalence ratio for co and counter-swirl domestic burners compared with non-swirl design on the thermal efficiency as well as CO emissions has been studied using liquefied petroleum gas (LPG. Also, the flame stability, and pot height, which is defined as the burner-to-pot distance (H, of the co and counter domestic burners were compared. The analysis of the results showed that, for both swirl burners co and counter one the thermal efficiency under all operation conditions tested is higher than the non-swirled burner (base burner. For example, the thermal efficiency increased by 8.8%, and 5.8% than base burner for co and counter swirl, respectively at Reynolds number equal 2000 and equivalence ratio 1. The co and counter swirl burners show lower CO emission than the base burner. The co swirl burner has wider operation range than counter swirl. With the increase of pot height, the thermal efficiency of all burners decreases because the flame and combustion gases are cooled due to mixing with ambient air. As a result, the heat transfer is decreased due to atmospheric loss, which decrease the thermal efficiency.

  9. DESIGN AND DEVELOPMENT OF MILD COMBUSTION BURNER

    Directory of Open Access Journals (Sweden)

    M.M. Noor

    2013-12-01

    Full Text Available This paper discusses the design and development of the Moderate and Intense Low oxygen Dilution (MILD combustion burner using Computational Fluid Dynamics (CFD simulations. The CFD commercial package was used to simulate preliminary designs for the burner before the final design was sent to the workshop for fabrication. The burner is required to be a non-premixed and open burner. To capture and use the exhaust gas, the burner was enclosed within a large circular shaped wall with an opening at the top. An external EGR pipe was used to transport the exhaust gas which was mixed with the fresh oxidant. To control the EGR and exhaust flow, butterfly valves were installed at the top opening as a damper to close the exhaust gas flow at a certain ratio for EGR and exhaust out to the atmosphere. High temperature fused silica glass windows were installed to view and capture images of the flame and analyze the flame propagation. The burner simulation shows that MILD combustion was achieved for the oxygen mole fraction of 3-13%. The final design of the burner was fabricated and ready for the experimental validation.

  10. The EXCYT RIB facility at LNS

    Energy Technology Data Exchange (ETDEWEB)

    Ciavola, G. [Inst. Nazionale di Fisica Nucleare, Catania (Italy). Lab. Nazionale del Sud; Alba, R. [Inst. Nazionale di Fisica Nucleare, Catania (Italy). Lab. Nazionale del Sud; Calabretta, L. [Inst. Nazionale di Fisica Nucleare, Catania (Italy). Lab. Nazionale del Sud; Cuttone, G. [Inst. Nazionale di Fisica Nucleare, Catania (Italy). Lab. Nazionale del Sud; Di Bartolo, G. [Inst. Nazionale di Fisica Nucleare, Catania (Italy). Lab. Nazionale del Sud; Gammino, S. [Inst. Nazionale di Fisica Nucleare, Catania (Italy). Lab. Nazionale del Sud; Migneco, E. [Inst. Nazionale di Fisica Nucleare, Catania (Italy). Lab. Nazionale del Sud; Raia, G. [Inst. Nazionale di Fisica Nucleare, Catania (Italy). Lab. Nazionale del Sud; Rifuggiato, D. [Inst. Nazionale di Fisica Nucleare, Catania (Italy). Lab. Nazionale del Sud; Rovelli, A. [Inst. Nazionale di Fisica Nucleare, Catania (Italy). Lab. Nazionale del Sud; Sura, J. [Inst. Nazionale di Fisica Nucleare, Catania (Italy). Lab. Nazionale del Sud; Vinciguerra, D. [Inst. Nazionale di Fisica Nucleare, Catania (Italy). Lab. Nazionale del Sud; Wollnik, H. [Inst. Nazionale di Fisica Nucleare, Catania (Italy). Lab. Nazionale del Sud

    1996-11-11

    EXCYT, a project for a low energy ISOL facility at LNS, has been funded. It is based on two already existing particle accelerators. A K=800 superconducting cyclotron will deliver the primary beam of ions A{<=}48; E=50-80 MeV/amu. After its interaction in a thick target, the negatively ionized radioactive products (A<80) will be post-accelerated to 0.2-8 MeV/amu by a 15 MV SMP tandem. A description of the facility, including the fully redesigned ion optics, an overview of the design problems and the expected secondary beam intensities are presented. (orig.).

  11. The EXCYT RIB facility at LNS

    International Nuclear Information System (INIS)

    Ciavola, G.; Alba, R.; Calabretta, L.; Cuttone, G.; Di Bartolo, G.; Gammino, S.; Migneco, E.; Raia, G.; Rifuggiato, D.; Rovelli, A.; Sura, J.; Vinciguerra, D.; Wollnik, H.

    1996-01-01

    EXCYT, a project for a low energy ISOL facility at LNS, has been funded. It is based on two already existing particle accelerators. A K=800 superconducting cyclotron will deliver the primary beam of ions A≤48; E=50-80 MeV/amu. After its interaction in a thick target, the negatively ionized radioactive products (A<80) will be post-accelerated to 0.2-8 MeV/amu by a 15 MV SMP tandem. A description of the facility, including the fully redesigned ion optics, an overview of the design problems and the expected secondary beam intensities are presented. (orig.)

  12. An LNS Approach for Container Stowage Multi-port Master Planning

    DEFF Research Database (Denmark)

    Pacino, Dario

    2013-01-01

    The generation of competitive stowage plans have become a priority for the shipping industry. Stowage planning is NP-hard and is a challenging optimization problem in practice. Two-phase decomposition approaches have proved to give viable solutions. We propose a large neighborhood search (LNS) to...

  13. Surface ignition behaviors of methane–air mixture in a gas oven burner

    International Nuclear Information System (INIS)

    Ryu, Jungwan; Kwon, Jongseo; Kim, Ryanggyun; Kim, Minseong; Kim, Youngsoo; Jeon, Chunghwan; Song, Juhun

    2014-01-01

    In a gas oven burner, commonly used as a residential appliance, a surface igniter is a critical component for creating a pilot flame near the surface that can propagate safely back to the nozzle of the burner. The igniter should meet critical operating requirements: a lower surface temperature needed to ignite a methane–air mixture and a stable/safe ignition sustained. Otherwise, such failure would result in an instantaneous peak in carbon monoxide emission and a safety hazard inside a closed oven. Several theoretical correlations have been used to predict ignition temperature as well as the critical ignition/extinction limit for a stagnation flow ignition. However, there have only been a few studies on ignition modes or relevant stability analysis, and therefore a more detailed examination of the transient ignition process is required. In this study, a high-speed flame visualization technique with temperature measurement was employed to reveal a surface ignition phenomenon and subsequent flame propagation of a cold combustible methane–air mixture in a gas oven burner. The operating parameters were the temperature–time history of the igniter surface, mixture velocity, and the distance of the igniter from the nozzle. The surface ignition temperatures were analyzed for such parameters under a safe ignition mode, while several abnormal modes leading to ignition failure were also recognized. - Highlights: •We revealed a surface ignition behavior of combustible mixture in gas oven burner. •We employed a flame visualization technique with temperature measurement. •We evaluated effects of parameters such as lifetime, mixture velocity and igniter distance. •We recognized several abnormal modes leading to ignition failure

  14. Effect of cycled combustion ageing on a cordierite burner plate

    International Nuclear Information System (INIS)

    Garcia, Eugenio; Gancedo, J. Ramon; Gracia, Mercedes

    2010-01-01

    A combination of 57 Fe-Moessbauer spectroscopy and X-ray Powder Diffraction analysis has been employed to study modifications in chemical and mechanical stability occurring in a cordierite burner aged under combustion conditions which simulate the working of domestic boilers. Moessbauer study shows that Fe is distributed into the structural sites of the cordierite lattice as Fe 2+ and Fe 3+ ions located mostly at octahedral sites. Ferric oxide impurities, mainly hematite, are also present in the starting cordierite material accounting for ≅40% of the total iron phases. From Moessbauer and X-ray diffraction data it can be deduced that, under the combustion conditions used, new crystalline phases were formed, some of the substitutional Fe 3+ ions existing in the cordierite lattice were reduced to Fe 2+ , and ferric oxides underwent a sintering process which results in hematite with higher particle size. All these findings were detected in the burner zone located in the proximity of the flame and were related to possible chemical reactions which might explain the observed deterioration of the burner material. Research Highlights: →Depth profile analyses used as a probe to understand changes in refractory structure. →All changes take place in the uppermost surface of the burner, close to the flame. →Reduction to Fe 2+ of substitutional Fe 3+ ions and partial cordierite decomposition. →Heating-cooling cycling induces a sintering of the existing iron oxide particles. →Chemical changes can explain the alterations observed in the material microstructure.

  15. The new low-NO{sub x} burner

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Masato [Joban Joint Power Corporation, Ltd., Nagasaki (Japan); Domoto, Kazuhiro; Tanaka, Ryuichiro [Mitsubishi Heavy Industries, Ltd., Nagasaki (Japan). Boiler Engineering Dept. Power Systems; Matsumoto, Keigo [Mitsubishi Heavy Industries, Ltd., Nagasaki (Japan). Combustion Lab.

    2013-11-01

    Burner design requires good ignitability, high burn-up rate and low NO{sub x} emissions. Mitsubishi Heavy Industries Ltd. (MHI) developed a low-NO{sub x} burner which meets the aforementioned requirements. It also needs less combustion air, the burner nozzle is subjected to less thermal stresses, and the potential of NO{sub x} corrosion is being reduced. (orig.)

  16. DESIGN REPORT: LOW-NOX BURNERS FOR PACKAGE BOILERS

    Science.gov (United States)

    The report describes a low-NOx burner design, presented for residual-oil-fired industrial boilers and boilers cofiring conventional fuels and nitrated hazardous wastes. The burner offers lower NOx emission levels for these applications than conventional commercial burners. The bu...

  17. Research on the Improvement of a Natural Gas Fired Burner for the CHP Application in a Central Heating Boiler using Radiant Burner Technology

    Energy Technology Data Exchange (ETDEWEB)

    Bieleveld, T.

    2010-08-15

    These days, the reduction of CO2 emissions from combustion devices is one of the main priorities for each design improvement. For the domestic use of the central heating boiler, Microgen Engine Corporation produces free piston Stirling engines for the Combined Heat and Power (CHP) application in these central heating boilers (Dutch: 'HRe ketel'). With CHP, the generation of electricity and heat are combined to increase overall efficiency, as heat is generally a waste product from the combustion to electric generation process. In this application, the Stirling engine, which can be defined as an external combustion engine, is heated by a natural gas fired engine-burner and cooled by a coolant flow. The heat transfer into the engine is converted into mechanical work and a heat flux from the engine. The mechanical work is used to produce electricity via a linear alternator. Heat in the flue gasses from the engine-burner is reused in a secondary burner and condensing heat exchanger. The coolant flow from the engine, after passing the secondary burner, is used for heating purposes. The heat transfer from engine-burner to the Stirling engine is analyzed and via several motivations it is found that it is favorable to improve fuel to electric conversion efficiency, for which the heat transfer efficiency of the engine-burner to the Stirling engine should be improved, as the engine design is not to be altered. From an initially developed linear free piston Stirling engine model and measurements performed at Microgen Engine Corporation, St. Petersborough, (UK), the engine power demand and engine-burner performance are found. The results are used to visualize the current energy flows of the Stirling engine and engine burner subsystem. The heat transfer to the engine is analyzed to find possible heat transfer improvements. It is concluded that heat transfer from the engine-burner to the engine can be approved if the flue losses due to convective heat transfer are

  18. Effect of cycled combustion ageing on a cordierite burner plate

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Eugenio [Instituto de Ceramica y Vidrio, CSIC, c/ Kelsen 5, Campus de Cantoblanco, 28049 Madrid (Spain); Gancedo, J. Ramon [Instituto de Quimica Fisica ' Rocasolano' , CSIC, c/ Serrano 119, 28006 Madrid (Spain); Gracia, Mercedes, E-mail: rocgracia@iqfr.csic.es [Instituto de Quimica Fisica ' Rocasolano' , CSIC, c/ Serrano 119, 28006 Madrid (Spain)

    2010-11-15

    A combination of {sup 57}Fe-Moessbauer spectroscopy and X-ray Powder Diffraction analysis has been employed to study modifications in chemical and mechanical stability occurring in a cordierite burner aged under combustion conditions which simulate the working of domestic boilers. Moessbauer study shows that Fe is distributed into the structural sites of the cordierite lattice as Fe{sup 2+} and Fe{sup 3+} ions located mostly at octahedral sites. Ferric oxide impurities, mainly hematite, are also present in the starting cordierite material accounting for {approx_equal}40% of the total iron phases. From Moessbauer and X-ray diffraction data it can be deduced that, under the combustion conditions used, new crystalline phases were formed, some of the substitutional Fe{sup 3+} ions existing in the cordierite lattice were reduced to Fe{sup 2+}, and ferric oxides underwent a sintering process which results in hematite with higher particle size. All these findings were detected in the burner zone located in the proximity of the flame and were related to possible chemical reactions which might explain the observed deterioration of the burner material. Research Highlights: {yields}Depth profile analyses used as a probe to understand changes in refractory structure. {yields}All changes take place in the uppermost surface of the burner, close to the flame. {yields}Reduction to Fe{sup 2+} of substitutional Fe{sup 3+} ions and partial cordierite decomposition. {yields}Heating-cooling cycling induces a sintering of the existing iron oxide particles. {yields}Chemical changes can explain the alterations observed in the material microstructure.

  19. Premixed combustion on ceramic foam burners

    NARCIS (Netherlands)

    Bouma, P.H.; Goey, de L.P.H.

    1999-01-01

    Combustion of a lean premixed methane–air mixture stabilized on a ceramic foam burner has been studied. The stabilization of the flame in the radiant mode has been simulated using a one-dimensional numerical model for a burner stabilized flat-flame, taking into account the heat transfer between the

  20. Altitude Performance Characteristics of Tail-pipe Burner with Convergingconical Burner Section on J47 Turbojet Engine

    Science.gov (United States)

    Prince, William R; Mcaulay, John E

    1950-01-01

    An investigation of turbojet-engine thrust augmentation by means of tail-pipe burning was conducted in the NACA Lewis altitude wind tunnel. Performance data were obtained with a tail-pipe burner having a converging conical burner section installed on an axial-flow-compressor type turbojet engine over a range of simulated flight conditions and tail-pipe fuel-air ratios with a fixed-area exhaust nozzle. A maximum tail-pipe combustion efficiency of 0.86 was obtained at an altitude of 15,000 feet and a flight Mach number of 0.23. Tail-pipe burner operation was possible up to an altitude of 45,000 feet at a flight Mach number of 0.23.

  1. Minor actinide transmutation using minor actinide burner reactors

    International Nuclear Information System (INIS)

    Mukaiyama, T.; Yoshida, H.; Gunji, Y.

    1991-01-01

    The concept of minor actinide burner reactor is proposed as an efficient way to transmute long-lived minor actinides in order to ease the burden of high-level radioactive waste disposal problem. Conceptual design study of minor actinide burner reactors was performed to obtain a reactor model with very hard neutron spectrum and very high neutron flux in which minor actinides can be fissioned efficiently. Two models of burner reactors were obtained, one with metal fuel core and the other with particle fuel core. Minor actinide transmutation by the actinide burner reactors is compared with that by power reactors from both the reactor physics and fuel cycle facilities view point. (author)

  2. Porosity effects in flame length of the porous burners

    Directory of Open Access Journals (Sweden)

    Fatemeh Bahadori

    2014-10-01

    Full Text Available Furnaces are the devices for providing heat to the industrial systems like boilers, gas turbines and etc. The main challenge of furnaces is emission of huge air pollutants. However, porous burners produce less contaminant compared to others. The quality of the combustion process in the porous burners depends on the length of flame in the porous medium. In this paper, the computational fluid dynamic (CFD is used to investigate the porosity effects on the flame length of the combustion process in porous burner. The simulation results demonstrate that increasing the porosity increases the flame length and the combustion zone extends forward. So, combustion quality increases and production of carbon monoxide decrease. It is possible to conclude that temperature distribution in low porosity burner is lower and more uniform than high porosity one. Therefore, by increasing the porosity of the burner, the production of nitrogen oxides increases. So, using an intermediate porosity in the burner appears to be reasonable.

  3. RF torch discharge combined with conventional burner

    International Nuclear Information System (INIS)

    Janca, J.; Tesar, C.

    1996-01-01

    The design of the combined flame-rf-plasma reactor and experimental examination of this reactor are presented. For the determination of the temperature in different parts of the combined burner plasma the methods of emission spectroscopy were used. The temperatures measured in the conventional burner reach the maximum temperature 1900 K but in the burner with the superimposed rf discharge the neutral gas temperature substantially increased up to 2600 K but also the plasma volume increases substantially. Consequently, the resident time of reactants in the reaction zone increases

  4. Efficient industrial burner control of a flexible burner management system; Effiziente industrielle Brennertechnik durch Einsatz flexibler Feuerungsautomaten

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Ulrich; Saenger, Peter [Siemens AG, Rastatt (Germany)

    2012-02-15

    Compactness and flexibility of a burner control system is a very important issue. With a few types a wide range in different industrial applications should be covered. This paper presents different applications of a new burner control system: heating of cooling lines in glass industry, steam generation and air heating for a pistachio roastery and in grain dryers. (orig.)

  5. CHP Integrated with Burners for Packaged Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Castaldini, Carlo; Darby, Eric

    2013-09-30

    The objective of this project was to engineer, design, fabricate, and field demonstrate a Boiler Burner Energy System Technology (BBEST) that integrates a low-cost, clean burning, gas-fired simple-cycle (unrecuperated) 100 kWe (net) microturbine (SCMT) with a new ultra low-NOx gas-fired burner (ULNB) into one compact Combined Heat and Power (CHP) product that can be retrofit on new and existing industrial and commercial boilers in place of conventional burners. The Scope of Work for this project was segmented into two principal phases: (Phase I) Hardware development, assembly and pre-test and (Phase II) Field installation and demonstration testing. Phase I was divided into five technical tasks (Task 2 to 6). These tasks covered the engineering, design, fabrication, testing and optimization of each key component of the CHP system principally, ULNB, SCMT, assembly BBEST CHP package, and integrated controls. Phase I work culminated with the laboratory testing of the completed BBEST assembly prior to shipment for field installation and demonstration. Phase II consisted of two remaining technical tasks (Task 7 and 8), which focused on the installation, startup, and field verification tests at a pre-selected industrial plant to document performance and attainment of all project objectives. Technical direction and administration was under the management of CMCE, Inc. Altex Technologies Corporation lead the design, assembly and testing of the system. Field demonstration was supported by Leva Energy, the commercialization firm founded by executives at CMCE and Altex. Leva Energy has applied for patent protection on the BBEST process under the trade name of Power Burner and holds the license for the burner currently used in the product. The commercial term Power Burner is used throughout this report to refer to the BBEST technology proposed for this project. The project was co-funded by the California Energy Commission and the Southern California Gas Company (SCG), a

  6. Burner for a wood burning furnace

    Energy Technology Data Exchange (ETDEWEB)

    Nolting, H

    1981-12-10

    The burner according to the invention consists of a horizontal tube, whose front wall is penetrated by an intake pipe, which is surrounded by a pipe duct and several divided shells, which are arranged below the pipe duct. The front wall is also provided with air openings. The intake pipe is provided with a spiral and moves chopped wood into the burner.

  7. Evaluating the efficacy of a minor actinide burner

    International Nuclear Information System (INIS)

    Dobbin, K.D.; Kessler, S.F.; Nelson, J.V.; Omberg, R.P.; Wootan, D.W.

    1993-06-01

    The efficacy of a minor actinide burner can be evaluated by comparing safety and economic parameters to the support ratio. Minor actinide mass produced per unit time in this number of Light Water Reactors (LWRs) can be burned during the same time period in one burner system. The larger the support ratio for a given set of safety and economic parameters, the better. To illustrate this concept, the support ratio for selected Liquid Metal Reactor (LMR) burner core designs was compared with corresponding coolant void worths, a fundamental safety concern following the Chernobyl accident. Results can be used to evaluate the cost in reduced burning of minor actinides caused by LMR sodium void reduction efforts or to compare with other minor actinide burner systems

  8. First operations of the LNS heavy ions facility

    International Nuclear Information System (INIS)

    Calabretta, L.; Ciavola, G.; Cuttone, G.; Gammino, S.; Gmaj, P.; Migneco, E.; Raia, G.; Rifuggiato, D.; Rovelli, A.; Sura, J.; Scuderi, V.; Acerbi, E.; Alessandria, F.; Bellomo, G.; Bosotti, A.; Martinis, C. de; Giove, D.; Michelato, P.; Pagani, C.; Rossi, L.

    1996-01-01

    A heavy ion facility is now available at laboratorio nazionale del Sud (LNS) of Catania. It can deliver beams with an energy up to 100 MeV/amu. The facility is based on a 15 MV HVEC tandem and a K=800 superconducting cyclotron as booster. During the last year, the facility came into operation. A 58 Ni beam delivered by the tandem has been radially injected in the SC and then has been accelerated and extracted at 30 MeV/amu. In this paper the status of the facility together with the experience gained during the commissioning will be extensively reported. (orig.)

  9. Design and construction of an air inductor burner

    International Nuclear Information System (INIS)

    Martinez, Camilo; Cardona, Mario; Arrieta, Andres Amell

    2001-01-01

    This article presents research results performed with the purpose of obtain design parameters, construction, and air inductor burner operation, which are used in industrial combustion systems, in several processes such as: metal fusion (fusion furnaces), fluids heating (immerse heating tubes), steam production (steam boiler), drying processes, etc. In order to achieve such objectives, a prototype with thermal power modulation from 6 to 52 kW, was built to be either operated with natural gas or with LPG. The burner was built taking in mind the know how (design procedure) developed according to theoretical schemes of different bibliographic references and knowledge of the research group in gas science and technology of the University of Antioquia. However, with such procedure only the burner mixer is dimensioned and five parameters must to be selected by the designer: burner thermal power, primary aeration ratio, counter pressure at combustion chamber, air pressure admission and gas fuel intended to use. For head design we took in mind research done before by the group of science and technology in gas research: Mono port and bar burner heads with their respective stabilization flame systems

  10. Studies on a burner used biomass pellets as fuel. Performance of a spiral vortex pellet burner

    Energy Technology Data Exchange (ETDEWEB)

    Iwao, Toshio

    1987-12-21

    In order to develop a small size burner with high performance using biomass pellets fuel substitute for fuel oil, the burning performance of a spiral vortex pallet burner has been studied. An experimental equipment for the pellet burning is made up of a fuel supply unit, combustion chamber and a furnace. The used woody pellet is made of mixed sawdust and bark; with water content of 10.29%, particle diameter of 5.5-9mm, length of 5-50mm, and, apparent and real specific gravities are 0.59 and 1.334 respectively. The pellets are sent to bottom of the combustion chamber, spiral vortex combustion are carried out with blown air, the ashes and unburnt residues are discharged to out of combustion chamber with spiral vortex hot gases. As the result, it was clarified that the formation of the burning layers in a burner is required to be in order of the layers of ash, oxidation, reduction and carbonization up to the upper layer for high burning performance, and the formation of the layer is influenced by the condition of sedimentation of pellets in the combustion chamber. In the meanwhile the burning performance of the burner is influenced by the quantity of blast, the rate of feeding, and by the time of pre-heating in the combustion chamber. (23 figs, 5 refs)

  11. Multifuel burners based on the porous burner technology for the application in fuel cell systems; Mehrstofffaehige Brenner auf Basis der Porenbrennertechnik fuer den Einsatz in Brennstoffzellensystemen

    Energy Technology Data Exchange (ETDEWEB)

    Diezinger, S.

    2006-07-01

    The present doctoral thesis describes the development of multifuel burners based on the porous burner technology for the application in hydrocarbon driven fuel cell systems. One objective of such burners is the heating of the fuel cell system to the operating temperature at the cold start. In stationary operation the burner has to postcombust the waste gases from the fuel cell and the gas processing system in order to reduce the pollutant emissions. As the produced heat is required for endothermal processes like the steam reforming the burner has a significant influence on the system's efficiency. The performed investigations are targeting on a gasoline driven PEMFC-System with steam reforming. In such systems the burner has to be capable to combust the system's fuel gasoline at the cold start, a low calorific fuel cell offgas (HU = 6,4 MJ/kg) in stationary operation and a hydrogen rich gas in the case of an emergency shut down. Pre-tests revealed that in state of the art porous burners the flame front of hydrogen/air combustion can only be stabilized at very high excess air ratios. In basic investigations concerning the stabilization of flame fronts in porous media the dominant influence parameters were determined. Based on this findings a new flame trap was developed which increases the operational range with hydrogen rich mixtures significantly. Furthermore the burning velocity at stationary combustion in porous media was investigated. The dependency of the porous burning velocity on the excess air ratio for different hydrocarbons and hydrogen as well as for mixtures of both was determined. The results of these basic investigations were applied for the design of a multifuel burner. In order to achieve an evaporation of the gasoline without the use of additional energy, an internal heat exchanger section for heating the combustion air was integrated into the burner. Additionally different experimental and numerical methods were applied for designing the

  12. Influence of burner form and pellet type on domestic pellet boiler performance

    Science.gov (United States)

    Rastvorov, D. V.; Osintsev, K. V.; Toropov, E. V.

    2017-10-01

    The study presents combustion and emission results obtained using two serial pellet boilers of the same heating capacity 40 kW. These boilers have been designed by producers for domestic conditions of exploitation. The principal difference between boilers was the type of the burner. The study concerns the efficiency and ecological performance difference between burners of circular and rectangular forms. The features of the combustion process in both types of burners were studied when boiler operated with different sorts of pellets. The results suggest that the burner of circular form excels the rectangular form burner. However, there is some difference of NOx emission between circular and rectangular burners.

  13. First operations of the LNS heavy ions facility

    Energy Technology Data Exchange (ETDEWEB)

    Calabretta, L. [INFN-LNS, Catania (Italy); Ciavola, G. [INFN-LNS, Catania (Italy); Cuttone, G. [INFN-LNS, Catania (Italy); Gammino, S. [INFN-LNS, Catania (Italy); Gmaj, P. [INFN-LNS, Catania (Italy); Migneco, E. [INFN-LNS, Catania (Italy); Raia, G. [INFN-LNS, Catania (Italy); Rifuggiato, D. [INFN-LNS, Catania (Italy); Rovelli, A. [INFN-LNS, Catania (Italy); Sura, J. [INFN-LNS, Catania (Italy); Scuderi, V. [INFN-LNS, Catania (Italy); Acerbi, E. [INFN-sezione di Milano (Italy)]|[Univ. degli studi di Milano, Lab. LASA (Italy); Alessandria, F. [INFN-sezione di Milano (Italy)]|[Univ. degli studi di Milano, Lab. LASA (Italy); Bellomo, G. [INFN-sezione di Milano (Italy)]|[Univ. degli studi di Milano, Lab. LASA (Italy); Bosotti, A. [INFN-sezione di Milano (Italy)]|[Univ. degli studi di Milano, Lab. LASA (Italy); Martinis, C. de [INFN-sezione di Milano (Italy)]|[Univ. degli studi di Milano, Lab. LASA (Italy); Giove, D. [INFN-sezione di Milano (Italy)]|[Univ. degli studi di Milano, Lab. LASA (Italy); Michelato, P. [INFN-sezione di Milano (Italy)]|[Univ. degli studi di Milano, Lab. LASA (Italy); Pagani, C. [INFN-sezione di Milano (Italy)]|[Univ. degli studi di Milano, Lab. LASA (Italy); Rossi, L. [INFN-sezione di Milano (Italy)]|[Univ. degli studi di Milano, Lab. LASA (Italy)

    1996-11-11

    A heavy ion facility is now available at laboratorio nazionale del Sud (LNS) of Catania. It can deliver beams with an energy up to 100 MeV/amu. The facility is based on a 15 MV HVEC tandem and a K=800 superconducting cyclotron as booster. During the last year, the facility came into operation. A {sup 58}Ni beam delivered by the tandem has been radially injected in the SC and then has been accelerated and extracted at 30 MeV/amu. In this paper the status of the facility together with the experience gained during the commissioning will be extensively reported. (orig.).

  14. Catalytic burners in larger boiler appliances

    Energy Technology Data Exchange (ETDEWEB)

    Silversand, Fredrik; Persson, Mikael (Catator AB, Lund (Sweden))

    2009-02-15

    This project focuses on the scale up of a Catator's catalytic burner technology to enable retrofit installation in existing boilers and the design of new innovative combinations of catalytic burners and boilers. Different design approaches are discussed and evaluated in the report and suggestions are made concerning scale-up. Preliminary test data, extracted from a large boiler installation are discussed together with an accurate analysis of technical possibilities following an optimization of the boiler design to benefit from the advantages of catalytic combustion. The experimental work was conducted in close collaboration with ICI Caldaie (ICI), located in Verona, Italy. ICI is a leading European boiler manufacturer in the effect segment ranging from about 20 kWt to several MWt. The study shows that it is possibly to scale up the burner technology and to maintain low emissions. The boilers used in the study were designed around conventional combustion and were consequently not optimized for implementation of catalytic burners. From previous experiences it stands clear that the furnace volume can be dramatically decreased when applying catalytic combustion. In flame combustion, this volume is normally dimensioned to avoid flame impingement on cold surfaces and to facilitate completion of the gas-phase reactions. The emissions of nitrogen oxides can be reduced by decreasing the residence time in the furnace. Even with the over-dimensioned furnace used in this study, we easily reached emission values close to 35 mg/kWh. The emissions of carbon monoxide and unburned hydrocarbons were negligible (less than 5 ppmv). It is possible to decrease the emissions of nitrogen oxides further by designing the furnace/boiler around the catalytic burner, as suggested in the report. Simultaneously, the size of the boiler installation can be reduced greatly, which also will result in material savings, i.e. the production cost can be reduced. It is suggested to optimize the

  15. Performance and analysis by particle image velocimetry (PIV) of cooker-top burners in Thailand

    International Nuclear Information System (INIS)

    Makmool, U.; Jugjai, S.; Tia, S.; Vallikul, P.; Fungtammasan, B.

    2007-01-01

    Cooker-top burners are used extensively in Thailand because of the rapid combustion and high heating-rates created by an impinging flame, which is characteristic of these types of burners. High thermal efficiency with low level of CO emissions is the most important performance criteria for these burners. The wide variation in reported performances of the burners appears to be due to the ad hoc knowledge gained through trial and error of the local manufacturers rather than sound scientific principles. This is extremely undesirable in view of safety, energy conservation and environmental protection. In the present work, a nationwide cooker-top burner performance survey and an implementation of a PIV technique to analyze the burner performance as well as advising local manufacturers were carried out. Experimental data were reported for the base line value of thermal efficiency of all the burners. The thermal performance parameters and dynamic properties of the flow field at a flame impingement area, i.e. velocity magnitude, turbulent intensity, vorticity and strain rate were also reported as a function of burner type, which was categorized into four types based on the configuration of the burner head: radial flow burners, swirling flow burners, vertical flow burners and porous radiant burners

  16. Assessment of PWR plutonium burners for nuclear energy centers

    International Nuclear Information System (INIS)

    Frankel, A.J.; Shapiro, N.L.

    1976-06-01

    The purpose of the study was to explore the performance and safety characteristics of PWR plutonium burners, to identify modifications to current PWR designs to enhance plutonium utilization, to study the problems of deploying plutonium burners at Nuclear Energy Centers, and to assess current industrial capability of the design and licensing of such reactors. A plutonium burner is defined to be a reactor which utilizes plutonium as the sole fissile addition to the natural or depleted uranium which comprises the greater part of the fuel mass. The results of the study and the design analyses performed during the development of C-E's System 80 plant indicate that the use of suitably designed plutonium burners at Nuclear Energy Centers is technically feasible

  17. Optimisation of efficiency and emissions in pellet burners

    International Nuclear Information System (INIS)

    Eskilsson, David; Roennbaeck, Marie; Samuelsson, Jessica; Tullin, Claes

    2004-01-01

    There is a trade-off between the emissions of nitrogen oxides (NO x ) and of unburnt hydrocarbons and carbon monoxide (OGC and CO). Decreasing the excess air results in lower NO x emission but also increased emission of unburnt. The efficiency increases, as the excess air is decreased until the losses due to incomplete combustion become too high. The often-high NO x emission in today's pellet burners can be significantly reduced using well-known techniques such as air staging. The development of different chemical sensors is very intensive and recently sensors for CO and OGC have been introduced on the market. These sensors may, together with a Lambda sensor, provide efficient control for optimal performance with respect to emissions and efficiency. In this paper, results from an experimental parameter study in a modified commercial burner, followed by Chemkin simulations with relevant input data and experiments in a laboratory reactor and in a prototype burner, are summarised. Critical parameters for minimisation of NO x emission from pellet burners are investigated in some detail. Also, results from tests of a new sensor for unburnt are reported. In conclusion, relatively simple design modifications can significantly decrease NO x emission from today's pellet burners

  18. Numerical study of geometric parameters effecting temperature and thermal efficiency in a premix multi-hole flat flame burner

    International Nuclear Information System (INIS)

    Saberi Moghaddam, Mohammad Hossein; Saei Moghaddam, Mojtaba; Khorramdel, Mohammad

    2017-01-01

    This paper investigates the geometric parameters related to thermal efficiency and pollution emission of a multi-hole flat flame burner. Recent experimental studies indicate that such burners are significantly influenced by both the use of distribution mesh and the size of the diameter of the main and retention holes. The present study numerically simulated methane-air premixed combustion using a two-step mechanism and constant mass diffusivity for all species. The results indicate that the addition of distribution mesh leads to uniform flow and maximum temperature that will reduce NOx emissions. An increase in the diameter of the main holes increased the mass flow which increased the temperature, thermal efficiency and NOx emissions. The size of the retention holes should be considered to decrease the total flow velocity and bring the flame closer to the burner surface, although a diameter change did not considerably improve temperature and thermal efficiency. Ultimately, under temperature and pollutant emission constraints, the optimum diameters of the main and retention holes were determined to be 5 and 1.25 mm, respectively. - Highlights: • Using distribution mesh led to uniform flow and reduced Nox pollutant by 53%. • 93% of total heat transfer occurred by radiation method in multi-hole burner. • Employing retention hole caused the flame become closer to the burner surface.

  19. MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS

    Energy Technology Data Exchange (ETDEWEB)

    E.G. Eddings; A. Molina; D.W. Pershing; A.F. Sarofim; T.H. Fletcher; H. Zhang; K.A. Davis; M. Denison; H. Shim

    2002-01-01

    The focus of this program is to provide insight into the formation and minimization of NO{sub x} in multi-burner arrays, such as those that would be found in a typical utility boiler. Most detailed studies are performed in single-burner test facilities, and may not capture significant burner-to-burner interactions that could influence NO{sub x} emissions. Thus, investigations of such interactions were made by performing a combination of single and multiple burner experiments in a pilot-scale coal-fired test facility at the University of Utah, and by the use of computational combustion simulations to evaluate full-scale utility boilers. In addition, fundamental studies on nitrogen release from coal were performed to develop greater understanding of the physical processes that control NO formation in pulverized coal flames--particularly under low NO{sub x} conditions. A CO/H{sub 2}/O{sub 2}/N{sub 2} flame was operated under fuel-rich conditions in a flat flame reactor to provide a high temperature, oxygen-free post-flame environment to study secondary reactions of coal volatiles. Effects of temperature, residence time and coal rank on nitrogen evolution and soot formation were examined. Elemental compositions of the char, tar and soot were determined by elemental analysis, gas species distributions were determined using FTIR, and the chemical structure of the tar and soot was analyzed by solid-state {sup 13}C NMR spectroscopy. A laminar flow drop tube furnace was used to study char nitrogen conversion to NO. The experimental evidence and simulation results indicated that some of the nitrogen present in the char is converted to nitric oxide after direct attack of oxygen on the particle, while another portion of the nitrogen, present in more labile functionalities, is released as HCN and further reacts in the bulk gas. The reaction of HCN with NO in the bulk gas has a strong influence on the overall conversion of char-nitrogen to nitric oxide; therefore, any model that

  20. Effects of elliptical burner geometry on partially premixed gas jet flames in quiescent surroundings

    Science.gov (United States)

    Baird, Benjamin

    This study is the investigation of the effect of elliptical nozzle burner geometry and partial premixing, both 'passive control' methods, on a hydrogen/hydrocarbon flame. Both laminar and turbulent flames for circular, 3:1, and 4:1 aspect ratio (AR) elliptical burners are considered. The amount of air mixed with the fuel is varied from fuel-lean premixed flames to fuel-rich partially premixed flames. The work includes measurements of flame stability, global pollutant emissions, flame radiation, and flame structure for the differing burner types and fuel conditions. Special emphasis is placed on the near-burner region. Experimentally, both conventional (IR absorption, chemiluminecent, and polarographic emission analysis,) and advanced (laser induced fluorescence, planar laser induced fluorescence, Laser Doppler Velocimetry (LDV), Rayleigh scattering) diagnostic techniques are used. Numerically, simulations of 3-dimensional laminar and turbulent reacting flow are conducted. These simulations are run with reduced chemical kinetics and with a Reynolds Stress Model (RSM) for the turbulence modeling. It was found that the laminar flames were similar in appearance and overall flame length for the 3:1 AR elliptical and the circular burner. The laminar 4:1 AR elliptical burner flame split into two sub-flames along the burner major axis. This splitting had the effect of greatly shortening the 4:1 AR elliptical burner flame to have an overall flame length about half of that of the circular and 3:1 AR elliptical burner flames. The length of all three burners flames increased with increasing burner exit equivalence ratio. The blowout velocity for the three burners increased with increase in hydrogen mass fraction of the hydrogen/propane fuel mixture. For the rich premixed flames, the circular burner was the most stable, the 3:1 AR elliptical burner, was the least stable, and the 4:1 AR elliptical burner was intermediate to the two other burners. This order of stability was due

  1. Fragmentation studies with the CHIMERA detector at LNS in Catania: recent progress

    Energy Technology Data Exchange (ETDEWEB)

    Pagano, A.; Alderighi, M.; Amorini, F.; Anzalone, A.; Arena, L.; Auditore, L.; Baran, V.; Bartolucci, M.; Berceanu, I.; Blicharska, J.; Brzychczyk, J.; Bonasera, A.; Borderie, B.; Bougault, R.; Bruno, M.; Cardella, G.; Cavallaro, S.; Chatterjee, M.B.; Chbihi, A.; Cibor, J.; Colonna, M.; D' Agostino, M.; Dayras, R.; De Filippo, E.; Di Toro, M.; Gawlikowicz, W.; Geraci, E.; Giustolisi, F.; Grzeszczuk, A.; Guazzoni, P.; Guinet, D.; Iacono-Manno, M.; Kowalski, S.; La Guidara, E.; Lanzano, G.; Lanzalone, G.; Le Neindre, N.; Li, S.; Lo Nigro, S.; Maiolino, C.; Majka, Z.; Manfredi, G.; Paduszynski, T.; Papa, M.; Petrovici, M.; Piasecki, E.; Pirrone, S.; Planeta, R.; Politi, G.; Pop, A.; Porto, F.; Rivet, M.F.; Rosato, E.; Rizzo, F.; Russo, S.; Russotto, P.; Sassi, M.; Sechi, G.; Simion, V.; Siwek-Wilczynska, K.; Skwira, I.; Sperduto, M.L.; Steckmeyer, J.C.; Swiderski, L.; Trifiro, A.; Trimarchi, M.; Vannini, G.; Vigilante, M.; Wieleczko, J.P.; Wilczynski, J.; Wu, H.; Xiao, Z.; Zetta, L.; Zipper, W

    2004-04-05

    The new detector CHIMERA, in its final 4{pi} configuration, has been installed at Laboratori Nazionali del Sud (LNS) in Catania in January 2003. Beams of different energies ranging from protons to Au ions were delivered by the Tandem and the Super Conducting Cyclotron for nuclear reaction studies, in agreement with the approval of the Scientific Advisory Committee of LNS. Recent experimental results confirm very low energy thresholds of the trigger (below 0.5 MeV/nucleon), ensured within a wide dynamical range. Good characteristics of identification of light charged particles and heavy fragments have been obtained by using three detection techniques: {delta}E-E, {delta}E-time of flight, and the Pulse-Shape discrimination method. We present results of recent analysis concerning the production of intermediate mass fragments (IMF) in semi-peripheral collisions. Our results combined with theoretical Boltzmann-Nordheim-Vlasov simulations clearly demonstrate the presence of very fast processes of IMF production in the overlapping region of the target and projectile nuclei during re-separation, i.e. in the time scale comparable with the collision time. Evidence for slower, sequential-like production of IMF's is also shown.

  2. Fragmentation studies with the CHIMERA detector at LNS in Catania: recent progress

    International Nuclear Information System (INIS)

    Pagano, A.; Alderighi, M.; Amorini, F.; Anzalone, A.; Arena, L.; Auditore, L.; Baran, V.; Bartolucci, M.; Berceanu, I.; Blicharska, J.; Brzychczyk, J.; Bonasera, A.; Borderie, B.; Bougault, R.; Bruno, M.; Cardella, G.; Cavallaro, S.; Chatterjee, M.B.; Chbihi, A.; Cibor, J.; Colonna, M.; D'Agostino, M.; Dayras, R.; De Filippo, E.; Di Toro, M.; Gawlikowicz, W.; Geraci, E.; Giustolisi, F.; Grzeszczuk, A.; Guazzoni, P.; Guinet, D.; Iacono-Manno, M.; Kowalski, S.; La Guidara, E.; Lanzano, G.; Lanzalone, G.; Le Neindre, N.; Li, S.; Lo Nigro, S.; Maiolino, C.; Majka, Z.; Manfredi, G.; Paduszynski, T.; Papa, M.; Petrovici, M.; Piasecki, E.; Pirrone, S.; Planeta, R.; Politi, G.; Pop, A.; Porto, F.; Rivet, M.F.; Rosato, E.; Rizzo, F.; Russo, S.; Russotto, P.; Sassi, M.; Sechi, G.; Simion, V.; Siwek-Wilczynska, K.; Skwira, I.; Sperduto, M.L.; Steckmeyer, J.C.; Swiderski, L.; Trifiro, A.; Trimarchi, M.; Vannini, G.; Vigilante, M.; Wieleczko, J.P.; Wilczynski, J.; Wu, H.; Xiao, Z.; Zetta, L.; Zipper, W.

    2004-01-01

    The new detector CHIMERA, in its final 4π configuration, has been installed at Laboratori Nazionali del Sud (LNS) in Catania in January 2003. Beams of different energies ranging from protons to Au ions were delivered by the Tandem and the Super Conducting Cyclotron for nuclear reaction studies, in agreement with the approval of the Scientific Advisory Committee of LNS. Recent experimental results confirm very low energy thresholds of the trigger (below 0.5 MeV/nucleon), ensured within a wide dynamical range. Good characteristics of identification of light charged particles and heavy fragments have been obtained by using three detection techniques: ΔE-E, ΔE-time of flight, and the Pulse-Shape discrimination method. We present results of recent analysis concerning the production of intermediate mass fragments (IMF) in semi-peripheral collisions. Our results combined with theoretical Boltzmann-Nordheim-Vlasov simulations clearly demonstrate the presence of very fast processes of IMF production in the overlapping region of the target and projectile nuclei during re-separation, i.e. in the time scale comparable with the collision time. Evidence for slower, sequential-like production of IMF's is also shown

  3. Design evaluation of the 20-cm (8-inch) secondary burner system

    International Nuclear Information System (INIS)

    Rode, J.S.

    1977-08-01

    This report describes an evaluation of the design of the existing 20-cm (8-inch) engineering-scale secondary burner system in the HTGR reprocessing cold pilot plant at General Atomic Co. The purpose of this evaluation is to assess the suitability of the existing design as a prototype of the HTGR Recycle Demonstration Facility (HRDF) secondary burner system and to recommend alternatives where the existing design is thought to be unsuitable as a prototype. This evaluation has led to recommendations for the parallel development of two integrated design concepts for a prototype secondary burner system. One concept utilizes the existing burner heating and cooling subsystems in order to minimize development risk, but simplifies a number of other features associated with remote maintenance and burner operation. The other concept, which offers maximum cost reduction, utilizes internal gas cooling of the burner, retains the existing heating subsystem for design compatibility, but requires considerable development to reduce the risk to acceptable limits. These concepts, as well as other design alternatives, are described and evaluated

  4. Design evaluation of the 40-cm (16-inch) primary burner system

    International Nuclear Information System (INIS)

    Rode, J.S.

    1977-06-01

    An evaluation is given of the design of the existing 40-cm (16-in.) engineering-scale primary burner system in the HTGR reprocessing cold pilot plant at General Atomic Co. The purpose of this evaluation is to assess the suitability of the existing design as a prototype of the HTGR Recycle Demonstration Facility (HRDF) primary burner system and to recommend alternatives where the existing design is thought to be unsuitable as a prototype. This evaluation has led to recommendations for the parallel development of two integrated design concepts for a prototype primary burner system. One concept utilizes the existing burner heating and cooling sub-systems in order to minimize development risk, but simplifies a number of other features associated with remote maintenance and burner operation. The other concept, which offers maximum cost reduction, utilizes direct contact hot gas heating and internal gas cooling of the burner, but requires considerable development to reduce the risk to acceptable limits. These concepts, as well as other design alternatives, are described and evaluated

  5. Some parameters and conditions defining the efficiency of burners ...

    Indian Academy of Sciences (India)

    irradiation in special burners, namely, in the blankets of ADS. Various views ... Ecologic gain – ratio of the ecologic threat level of initial LLW to that of final. LLW. .... For all burner types, the general tendency is that the increase of consumption.

  6. Characterization of combustion in a fabric singeing burner operating with varsol

    International Nuclear Information System (INIS)

    Quintana M, Juan C; Mendoza S, Cesar Camilo; Molina Alejandro

    2009-01-01

    The textile industry uses singeing burners to diminish the amount of pilling on surface fabrics. Some of these burners use Stoddard solvent which has high cost per unit of energy, high flammability and emits volatile organic compounds that pose an occupational safety hazard. This study characterized a singing burner operating with varsol performing measurements of temperature downstream the burner, air and fuel flows, and concentration of CO, CO 2 , O 2 and NO x . These measurements defined the most important characteristics of the Stoddard solvent flame that should be maintained to obtain a similar behavior in an eventual change to natural gas.

  7. Multi-ported, internally recuperated burners for direct flame impingement heating applications

    Energy Technology Data Exchange (ETDEWEB)

    Abbasi, Hamid A. (Naperville, IL); Kurek, Harry (Dyer, IN); Chudnovsky, Yaroslav (Skokie, IL); Lisienko, Vladimir G. (Ekaterinburg, RU); Malikov, German K. (Ekaterinburg, RU)

    2010-08-03

    A direct flame impingement method and apparatus employing at least one multi-ported, internally recuperated burner. The burner includes an innermost coaxial conduit having a first fluid inlet end and a first fluid outlet end, an outermost coaxial conduit disposed around the innermost coaxial conduit and having a combustion products outlet end proximate the first fluid inlet end of the innermost coaxial conduit and a combustion products inlet end proximate the first fluid outlet end of the innermost coaxial conduit, and a coaxial intermediate conduit disposed between the innermost coaxial conduit and the outermost coaxial conduit, whereby a second fluid annular region is formed between the innermost coaxial conduit and the intermediate coaxial conduit and a combustion products annular region is formed between the intermediate coaxial conduit and the outermost coaxial conduit. The intermediate coaxial conduit has a second fluid inlet end proximate the first fluid inlet end of the innermost coaxial conduit and a second fluid outlet end proximate the combustion products inlet end of the outermost coaxial conduit.

  8. Numerical simulations of a large scale oxy-coal burner

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Taeyoung [Korea Institute of Industrial Technology, Cheonan (Korea, Republic of). Energy System R and D Group; Sungkyunkwan Univ., Suwon (Korea, Republic of). School of Mechanical Engineering; Park, Sanghyun; Ryu, Changkook [Sungkyunkwan Univ., Suwon (Korea, Republic of). School of Mechanical Engineering; Yang, Won [Korea Institute of Industrial Technology, Cheonan (Korea, Republic of). Energy System R and D Group

    2013-07-01

    Oxy-coal combustion is one of promising carbon dioxide capture and storage (CCS) technologies that uses oxygen and recirculated CO{sub 2} as an oxidizer instead of air. Due to difference in physical properties between CO{sub 2} and N{sub 2}, the oxy-coal combustion requires development of burner and boiler based on fundamental understanding of the flame shape, temperature, radiation and heat flux. For design of a new oxy-coal combustion system, computational fluid dynamics (CFD) is an essential tool to evaluate detailed combustion characteristics and supplement experimental results. In this study, CFD analysis was performed to understand the combustion characteristics inside a tangential vane swirl type 30 MW coal burner for air-mode and oxy-mode operations. In oxy-mode operations, various compositions of primary and secondary oxidizers were assessed which depended on the recirculation ratio of flue gas. For the simulations, devolatilization of coal and char burnout by O{sub 2}, CO{sub 2} and H{sub 2}O were predicted with a Lagrangian particle tracking method considering size distribution of pulverized coal and turbulent dispersion. The radiative heat transfer was solved by employing the discrete ordinate method with the weighted sum of gray gases model (WSGGM) optimized for oxy-coal combustion. In the simulation results for oxy-model operation, the reduced swirl strength of secondary oxidizer increased the flame length due to lower specific volume of CO{sub 2} than N{sub 2}. The flame length was also sensitive to the flow rate of primary oxidizer. The oxidizer without N{sub 2} that reduces thermal NO{sub x} formation makes the NO{sub x} lower in oxy-mode than air-mode. The predicted results showed similar trends with measured temperature profiles for various oxidizer compositions. Further numerical investigations are required to improve the burner design combined with more detailed experimental results.

  9. Need to plan for a full-scale lns-physics program at the SSC

    International Nuclear Information System (INIS)

    White, A.R.

    1984-03-01

    Arguments for a full lns physics program at the SSC are enumerated and elaborated on. They are: first - the inadequacy of data from a minimal program, second - the potential fundamental significance of a high-energy soft physics collective phenomenon and third - the possible diffractive production of much of the interesting new physics that will be searched for

  10. Parametric Study of High-Efficiency and Low-Emission Gas Burners

    Directory of Open Access Journals (Sweden)

    Shuhn-Shyurng Hou

    2013-01-01

    Full Text Available The objective of this study is to investigate the influence of three significant parameters, namely, swirl flow, loading height, and semi-confined combustion flame, on thermal efficiency and CO emissions of a swirl flow gas burner. We focus particularly on the effects of swirl angle and inclination angle on the performance of the swirl flow burner. The results showed that the swirl flow burner yields higher thermal efficiency and emits lower CO concentration than those of the conventional radial flow burner. A greater swirl angle results in higher thermal efficiency and CO emission. With increasing loading height, the thermal efficiency increases but the CO emission decreases. For a lower loading height (2 or 3 cm, the highest efficiency occurs at the inclination angle 15°. On the other hand, at a higher loading height, 4 cm, thermal efficiency increases with the inclination angle. Moreover, the addition of a shield can achieve a great increase in thermal efficiency, about 4-5%, and a decrease in CO emissions for the same burner (swirl flow or radial flow.

  11. MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS; FINAL

    International Nuclear Information System (INIS)

    E.G. Eddings; A. Molina; D.W. Pershing; A.F. Sarofim; T.H. Fletcher; H. Zhang; K.A. Davis; M. Denison; H. Shim

    2002-01-01

    The focus of this program is to provide insight into the formation and minimization of NO(sub x) in multi-burner arrays, such as those that would be found in a typical utility boiler. Most detailed studies are performed in single-burner test facilities, and may not capture significant burner-to-burner interactions that could influence NO(sub x) emissions. Thus, investigations of such interactions were made by performing a combination of single and multiple burner experiments in a pilot-scale coal-fired test facility at the University of Utah, and by the use of computational combustion simulations to evaluate full-scale utility boilers. In addition, fundamental studies on nitrogen release from coal were performed to develop greater understanding of the physical processes that control NO formation in pulverized coal flames-particularly under low NO(sub x) conditions. A CO/H(sub 2)/O(sub 2)/N(sub 2) flame was operated under fuel-rich conditions in a flat flame reactor to provide a high temperature, oxygen-free post-flame environment to study secondary reactions of coal volatiles. Effects of temperature, residence time and coal rank on nitrogen evolution and soot formation were examined. Elemental compositions of the char, tar and soot were determined by elemental analysis, gas species distributions were determined using FTIR, and the chemical structure of the tar and soot was analyzed by solid-state(sup 13)C NMR spectroscopy. A laminar flow drop tube furnace was used to study char nitrogen conversion to NO. The experimental evidence and simulation results indicated that some of the nitrogen present in the char is converted to nitric oxide after direct attack of oxygen on the particle, while another portion of the nitrogen, present in more labile functionalities, is released as HCN and further reacts in the bulk gas. The reaction of HCN with NO in the bulk gas has a strong influence on the overall conversion of char-nitrogen to nitric oxide; therefore, any model that

  12. Design and analysis of the federal aviation administration next generation fire test burner

    Science.gov (United States)

    Ochs, Robert Ian

    The United States Federal Aviation Administration makes use of threat-based fire test methods for the certification of aircraft cabin materials to enhance the level of safety in the event of an in-flight or post-crash fire on a transport airplane. The global nature of the aviation industry results in these test methods being performed at hundreds of laboratories around the world; in some cases testing identical materials at multiple labs but yielding different results. Maintenance of this standard for an elevated level of safety requires that the test methods be as well defined as possible, necessitating a comprehensive understanding of critical test method parameters. The tests have evolved from simple Bunsen burner material tests to larger, more complicated apparatuses, requiring greater understanding of the device for proper application. The FAA specifies a modified home heating oil burner to simulate the effects of large, intense fires for testing of aircraft seat cushions, cargo compartment liners, power plant components, and thermal acoustic insulation. Recently, the FAA has developed a Next Generation (NexGen) Fire Test burner to replace the original oil burner that has become commercially unavailable. The NexGen burner design is based on the original oil burner but with more precise control of the air and fuel flow rates with the addition of a sonic nozzle and a pressurized fuel system. Knowledge of the fundamental flow properties created by various burner configurations is desired to develop an updated and standardized burner configuration for use around the world for aircraft materials fire testing and airplane certification. To that end, the NexGen fire test burner was analyzed with Particle Image Velocimetry (PIV) to resolve the non-reacting exit flow field and determine the influence of the configuration of burner components. The correlation between the measured flow fields and the standard burner performance metrics of flame temperature and

  13. Development of the Radiation Stabilized Distributed Flux Burner - Phase III Final Report

    Energy Technology Data Exchange (ETDEWEB)

    J. D. Sullivan; A. Webb

    1999-12-01

    The development and demonstration of the Radiation Stabilized Burner (RSB) was completed as a project funded by the US Department of Energy Office of Industrial Technologies. The technical goals of the project were to demonstrate burner performance that would meet or exceed emissions targets of 9 ppm NOx, 50 ppm CO, and 9 ppm unburned hydrocarbons (UHC), with all values being corrected to 3 percent stack oxygen, and incorporate the burner design into a new industrial boiler configuration that would achieve ultra-low emissions while maintaining or improving thermal efficiency, operating costs, and maintenance costs relative to current generation 30 ppm low NOx burner installations. Both the ultra-low NOx RSB and the RSB boiler-burner package are now commercially available.

  14. The influence of the furnace design on emissions from small wood pellet burners

    International Nuclear Information System (INIS)

    Aspfors, Jonas; Larfeldt, Jenny

    1999-01-01

    Two pellet burners have been installed and tested in a small scale boiler for house heating. The boiler is representative for the Swedish households and the burners, upwards and forward burning, are commercially available on the Swedish market. This work focuses on the boiler operation and particularly the potential of improved emissions by changing the furnace design. An insulation of the fireplace lowered the emission of CO by 50% and the emission of OGC by 60% for the upwards burning burner at low load. Modifying the furnace using baffles did not have any influence on the emissions. It is concluded that an increased temperature in the furnace is more important than an increased residence time of the combustible gases to decrease the emissions. At full load both burners emit approximately 300 mg CO per nm 3 gas and the emission of OGC are negligible. At half load the emissions of CO increased to 1000 mg/m n 3 and OGC to 125 mg/m n 3 in the upward burning burner. The forwards burning burner had a small increase in OGC to about 10 mg/m n 3 at half load while the emission of CO increased to 800 mg/m n 3 . The forward burning burner is less influenced on the furnace design compared to the upward burning burner. The comparatively high emissions of OGC for the upward burning burner is explained by the intermittent operation. However, it was possible to reduce the emissions from this burner by ceramic insulation of the furnace Project report from the program: Small scale combustion of biofuels. 3 refs, 12 figs, 2 tab, 1 appendix with 33 figs and 12 tabs

  15. Characteristics of premixed flames stabilized in an axisymmetric curved-wall jet burner with tip modification

    KAUST Repository

    Kim, Daejoong; Gil, Y. S.; Chung, TaeWon; Chung, Suk-Ho

    2009-01-01

    The stabilization characteristics of premixed flames in an axisymmetric curved-wall jet burner have been experimentally investigated. This burner utilized the Coanda effect on top of a burner tip. The initially spherical burner tip was modified to a

  16. Process development report: 0.40-m primary burner system

    International Nuclear Information System (INIS)

    Young, D.T.

    1978-04-01

    Fluidized bed combustion is required in reprocessing the graphite-based fuel elements from high-temperature gas-cooled reactor (HTGR) cores. This burning process requires combustion of beds containing both large particles and very dense particles, and also of fine graphite particles which elutriate from the bed. This report documents the successful long-term operation of the 0.40-m primary burner in burning crushed fuel elements. The 0.40-m system operation is followed from its first short heatup test in September 1976 to a > 40-h burning campaign that processed 20 LHTGR blocks in September 1977. The 0.40-m perforated conical gas distributor, scaled up from the 0.20-m primary burner, has proven reliable in safely burning even the largest, densest adhered graphite/fuel particle clusters originating from the crushing of loaded fuel elements. Such clusters had never been fed to the 0.20-m system. Efficient combustion of graphite fines using the pressurized recycle technique was demonstrated throughout the long-duration operation required to reduce a high carbon fresh feed bed to a low carbon particle bed. Again, such operation had never been completed on the 0.20-m system from which the 0.40-m burner was scaled. The successful completion of the tests was due, in part, to implementation of significant equipment revisions which were suggested by both the initial 0.40-m system tests and by results of ongoing development work on the 0.2-m primary burner. These revisions included additional penetrations in the burner tube side-wall for above-bed fines recycle, replacement and deletion of several metal bellows with bellows of more reliable design, and improvements in designs for burner alignment and feeder mechanisms. 76 figures, 8 tables

  17. Process development report: 0.20-m primary burner system

    International Nuclear Information System (INIS)

    Rickman, W.S.

    1978-09-01

    HTGR reprocessing consists of crushing the spent fuel elements to a size suitable for burning in a fluidized bed to remove excess graphite, separating the fissile and fertile particles, crushing and burning the SiC-coated fuel particles to remove the remainder of the carbon, dissolution and separation of the particles from insoluble materials, and solvent extraction separation of the dissolved uranium and thorium. Burning the crushed fuel elements is accomplished in a primary burner. This is a batch-continuous, fluidized-bed process utilizing above-bed gravity fines recycle. In gas-solid separation, a combination of a cyclone and porous metal filters is used. This report documents operational tests performed on a 0.20-m primary burner using crushed fuel representative of both Fort St. Vrain and large high-temperature gas-cooled reactor cores. The burner was reconstructed to a gravity fines recycle mode prior to beginning these tests. Results of two separate and successful 48-hour burner runs and several short-term runs have indicated the operability of this concept. Recommendations are made for future work

  18. Slurry burner for mixture of carbonaceous material and water

    Science.gov (United States)

    Nodd, D.G.; Walker, R.J.

    1985-11-05

    The present invention is intended to overcome the limitations of the prior art by providing a fuel burner particularly adapted for the combustion of carbonaceous material-water slurries which includes a stationary high pressure tip-emulsion atomizer which directs a uniform fuel into a shearing air flow as the carbonaceous material-water slurry is directed into a combustion chamber, inhibits the collection of unburned fuel upon and within the atomizer, reduces the slurry to a collection of fine particles upon discharge into the combustion chamber, and regulates the operating temperature of the burner as well as primary air flow about the burner and into the combustion chamber for improved combustion efficiency, no atomizer plugging and enhanced flame stability.

  19. Dependence of flame length on cross sections of burners

    Energy Technology Data Exchange (ETDEWEB)

    Hackeschmidt, M.

    1983-06-01

    This article analyzes the relation between the shape of burner muzzle and the resulting flame jet in a combustion chamber. Geometrical shapes of burner muzzles, either square, circular or triangular are compared as well as proportions of flame dimensions. A formula for calculating flame lengths is derived, for which the mathematical value 'contact profile radius' for burner muzzle shape is introduced. The formula for calculating flame lengths allows a partial replacement of the empirical flame mixing factor according to N.Q. Toai, 1981. The geometrical analysis does not include thermodynamic and reaction kinetic studies, which may be necessary for evaluating heterogenous (coal dust) combustion flames with longer burning time. (12 refs.)

  20. Development of strand burner for solid propellant burning rate studies

    International Nuclear Information System (INIS)

    Aziz, A; Mamat, R; Ali, W K Wan

    2013-01-01

    It is well-known that a strand burner is an apparatus that provides burning rate measurements of a solid propellant at an elevated pressure in order to obtain the burning characteristics of a propellant. This paper describes the facilities developed by author that was used in his studies. The burning rate characteristics of solid propellant have be evaluated over five different chamber pressures ranging from 1 atm to 31 atm using a strand burner. The strand burner has a mounting stand that allows the propellant strand to be mounted vertically. The strand was ignited electrically using hot wire, and the burning time was recorded by electronic timer. Wire technique was used to measure the burning rate. Preliminary results from these techniques are presented. This study shows that the strand burner can be used on propellant strands to obtain accurate low pressure burning rate data

  1. Effects of Burner Configurations on the Natural Oscillation Characteristics of Laminar Jet Diffusion Flames

    Directory of Open Access Journals (Sweden)

    K. R. V. Manikantachari

    2015-09-01

    Full Text Available In this work, effects of burner configurations on the natural oscillations of methane laminar diffusion flames under atmospheric pressure and normal gravity conditions have been studied experimentally. Three regimes of laminar diffusion flames, namely, steady, intermittent flickering and continuous flickering have been investigated. Burner configurations such as straight pipe, contoured nozzle and that having an orifice plate at the exit have been considered. All burners have the same area of cross section at the exit and same burner lip thickness. Flame height data has been extracted from direct flame video using MATLAB. Shadowgraph videos have been captured to analyze the plume width characteristics. Results show that, the oscillation characteristics of the orifice burner is significantly different from the other two burners; orifice burner produces a shorter flame and wider thermal plume width in the steady flame regime and the onset of the oscillation/flickering regimes for the orifice burner occurs at a higher fuel flow rate. In the natural flickering regime, the dominating frequency of flame flickering remains within a small range, 12.5 Hz to 15 Hz, for all the burners and for all fuel flow rates. The time-averaged flame length-scale parameters, such as the maximum and the minimum flame heights, increase with respect to the fuel flow rate, however, the difference in the maximum and the minimum flame heights remains almost constant.

  2. The acoustic response of burner-stabilised flat flames : a two-dimensional numerical analysis

    NARCIS (Netherlands)

    Rook, R.; Goey, de L.P.H.

    2003-01-01

    The response of burner-stabilized flat flames to acoustic perturbations is studied numerically. So far, one-dimensional models have been used to study this system. However, in most practical surface burners, the scale of the perforations in the burner plate is of the order of the flame thickness.

  3. A small porous-plug burner for studies of combustion chemistry and soot formation

    Science.gov (United States)

    Campbell, M. F.; Schrader, P. E.; Catalano, A. L.; Johansson, K. O.; Bohlin, G. A.; Richards-Henderson, N. K.; Kliewer, C. J.; Michelsen, H. A.

    2017-12-01

    We have developed and built a small porous-plug burner based on the original McKenna burner design. The new burner generates a laminar premixed flat flame for use in studies of combustion chemistry and soot formation. The size is particularly relevant for space-constrained, synchrotron-based X-ray diagnostics. In this paper, we present details of the design, construction, operation, and supporting infrastructure for this burner, including engineering attributes that enable its small size. We also present data for charactering the flames produced by this burner. These data include temperature profiles for three premixed sooting ethylene/air flames (equivalence ratios of 1.5, 1.8, and 2.1); temperatures were recorded using direct one-dimensional coherent Raman imaging. We include calculated temperature profiles, and, for one of these ethylene/air flames, we show the carbon and hydrogen content of heavy hydrocarbon species measured using an aerosol mass spectrometer coupled with vacuum ultraviolet photoionization (VUV-AMS) and soot-volume-fraction measurements obtained using laser-induced incandescence. In addition, we provide calculated mole-fraction profiles of selected gas-phase species and characteristic profiles for seven mass peaks from AMS measurements. Using these experimental and calculated results, we discuss the differences between standard McKenna burners and the new miniature porous-plug burner introduced here.

  4. Developement of porous media burner operating on waste vegetable oil

    International Nuclear Information System (INIS)

    Lapirattanakun, Arwut; Charoensuk, Jarruwat

    2017-01-01

    Highlights: • Steam was successfully applied to promote combustion of WVO. • A specially designed porous domain was an essential element for stable combustion of WVO. • The performance of WVO burner was in the range of cooking stove. • Nozzle clog up in domestic WVO burner can be avoided when replacing it with a steam-assisted nozzle. - Abstract: A newly designed cooking stove using Wasted Vegetable Oil (WVO) as fuel was introduced. Porous media, containing 2 cm diameter of spherical ceramic balls, was used as a flame stabilizer. Steam was successfully applied in a burner at this scale to atomize WVO droplet and entrain air into the combustion zone as well as to reduce soot and CO emission. DIN EN 203-1 testing standard was adopted and the experiment was conducted at various firing rate with the water flow rate at 0.16, 0.20 and 0.22 kg/min. Temperature, emissions, visible flame length, thermal efficiency as well as combustion efficiency were evaluated. Under the current WVOB design, it was suitable to operate the burner at the range of nominal firing rate between 325 and 548 kW/m"2 with water flow rate of 0.16 kg/min, at burner height to diameter ratio of 0.75, giving CO and NO_x emissions up to 171 and 40 ppm, respectively (at 6% O_2). Thermal efficiency was at around 28% where the combustion efficiency was approximately at 99.5%. The performance of WVO burner could be improved further if increasing the H/D ratio to 1.5, yielding thermal efficiency up to 42%.

  5. Nitrogen oxide suppression by using a new design of pulverized-coal burners

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Cameron, S.D.; Grekhov, L.L. [All-Russian Thermal Engineering Institute, Moscow (Russian Federation)

    1996-07-01

    The results of testing a low-NO{sub x} swirl burner are presented. This burner was developed by Babcock Energy Ltd., for reducing nitrogen oxide emissions when burning Ekibastuz and Kuznetsk low-caking coals in power boilers. The tests conducted at a large plant of the BEL Technological Center showed that the new burner reduces NO{sub x} emissions by approximately two times. 6 refs., 6 figs., 1 tab.

  6. Non-uniform velocity profile mechanism for flame stabilization in a porous radiant burner

    Energy Technology Data Exchange (ETDEWEB)

    Catapan, R.C.; Costa, M. [Mechanical Engineering Department, Instituto Superior Tecnico, Technical University of Lisbon, Avenida Rovisco Pais, 1049-001 Lisbon (Portugal); Oliveira, A.A.M. [Mechanical Engineering Department, Federal University of Santa Catarina, Campus Universitario Professor Joao David Ferreira Lima, 88040-900 Florianopolis, SC (Brazil)

    2011-01-15

    Industrial processes where the heating of large surfaces is required lead to the possibility of using large surface porous radiant burners. This causes additional temperature uniformity problems, since it is increasingly difficult to evenly distribute the reactant mixture over a large burner surface while retaining its stability and keeping low pollutant emissions. In order to allow for larger surface area burners, a non-uniform velocity profile mechanism for flame stabilization in a porous radiant burner using a single large injection hole is proposed and analyzed for a double-layered burner operating in open and closed hot (laboratory-scale furnace, with temperature-controlled, isothermal walls) environments. In both environments, local mean temperatures within the porous medium have been measured. For lower reactant flow rate and ambient temperature the flame shape is conical and anchored at the rim of the injection hole. As the volumetric flow rate or furnace temperature is raised, the flame undergoes a transition to a plane flame stabilized near the external burner surface. However, the stability range envelope remains the same in both regimes. (author)

  7. Industrial applications of Tenova FlexyTech flame-less low NOx burners

    International Nuclear Information System (INIS)

    Fantuzzi, M.; Ballarino, L.

    2008-01-01

    Environmental emissions constraints have led manufacturers to improve their low NO x recuperative burners. The development by Tenova of the FlexyTech Flame-less burners with low NO x emissions, even below the present 'Best Available Technology' limit of 40 ppm at 3% O 2 with furnace temperature 1250 C, air preheat 450 C, is described. The results achieved during the R and D programme have been also improved in the industrial installations. Some details and performances of the recent furnaces equipped with such burners are provided. (authors)

  8. Measurement of OH radical density in DBD-enhanced premixed burner flame by laser-induced fluorescence

    Science.gov (United States)

    Zaima, Kazunori; Sasaki, Koichi

    2013-09-01

    We examined OH density in DBD-enhanced premixed burner flame by laser-induced fluorescence (LIF). We ignited a premixed flame with CH4 /O2 / Ar mixture using a burner which worked as the ground electrode. The upper part of the flame was covered with a quartz tube, and we attached an aluminum electrode on the outside of the quartz tube. DBD inside the quartz tube was obtained between the aluminum electrode and the burner nozzle. The planar beam from a pulsed tunable laser excited OH in X2 Π (v'' = 0) to A2Σ+ (v' = 0) , and we captured two-dimensional distribution of the LIF intensity using an ICCD camera. We employed three pump lines of Q1(J=4, 8 and 10), and the rotational temperature of OH(X) was deduced from the ratio of the LIF intensities. The total density of OH was obtained from the LIF intensities and the rotational temperature. A principal experimental result was that no remarkable increase was observed in the OH density by the superposition of DBD. The correlation between the pulsed discharge current and the temporal variation of the OH density was not clear, suggesting that the oscillation of the OH density with a small amplitude is related to the transittion time constant between equilibrium and nonequilibrium combustion chemistries.

  9. Acoustic Pressure Oscillations Induced in I-Burner

    Science.gov (United States)

    Matsui, Kiyoshi

    Iwama et al. invented the I-burner to investigate acoustic combustion instability in solid-propellant rockets (Proceedings of ICT Conference, 1994, pp. 26-1 26-14). Longitudinal pressure oscillations were induced in the combustion chamber of a thick-walled rocket by combustion of a stepped-perforation grain (I-burner). These oscillations were studied here experimentally. Two I-burners with an internal diameter of 80 mm and a length of 1208 mm or 2240 mm were made. The grain had stepped perforations (20 and 42 mm in diameter and 657 and 160 mm in length, respectively). Longitudinal pressure oscillations always occur in two stages when an HTPB (hydroxyl-terminated polybutadiene)/AP (ammonium perchlorate)/aluminum-powder propellant burns (54 tests; the highest average pressure in the combustion chamber was 9.5 29 MPa), but no oscillations occur when an HTPB/AP propellant burns (29 tests). The pressure oscillations are essentially linear, but dissipation adds a nonlinear nature to them. In the first stage, the amplitudes are small and the first wave group predominates. In the next stage, the amplitudes are large and many wave groups are present. The change in the grain form accompanying the combustion affects the pressure oscillations.

  10. 300 MWe Burner Core Design with two Enrichment Zoning

    International Nuclear Information System (INIS)

    Song, Hoon; Kim, Sang Ji; Kim, Yeong Il

    2008-01-01

    KAERI has been developing the KALIMER-600 core design with a breakeven fissile conversion ratio. The core is loaded with a ternary metallic fuel (TRU-U-10Zr), and the breakeven characteristics are achieved without any blanket assembly. As an alternative plan, a KALIMER-600 burner core design has been also performed. In the early stage of the development of a fast reactor, the main purpose is an economical use of a uranium resource but nowadays in addition to the maximum utilization of a uranium resource, the burning of a high level radioactive waste is taken as an additional interest for the harmony of the environment. In way of constructing the commercial size reactor which has the power level ranging from 800 MWe to 1600 MWe, the demonstration reactor which has the power level ranging from 200 MWe to 600 MWe was usually constructed for the midterm stage to commercial size reactor. In this paper, a 300 MWe burner core design was performed with purpose of demonstration reactor for KALIMER-600 burner of 600 MWe. As a means to flatten the power distribution, instead of a single fuel enrichment scheme adapted in design of KALIMER-600 burner, the 2 enrichment zoning approach was adapted

  11. MA-burners efficiency parameters allowing for the duration of transmutation process

    International Nuclear Information System (INIS)

    Gulevich, A.; Zemskov, E.; Kalugin, A.; Ponomarev, L.; Seliverstov, V.; Seregin, M.

    2010-01-01

    Transmutation of minor actinides (MA) means their transforming into the fission products. Usually, MA-burner's transmutation efficiency is characterized by the static parameters only, such as the number of neutrons absorbed and the rate of MA feeding. However, the proper characterization of MA-burner's efficiency additionally requires the consideration of parameters allowing for the duration of the MA transmutation process. Two parameters of that kind are proposed: a) transmutation time τ - mean time period from the moment a mass of MA is loaded into the burner's fuel cycle to be transmuted to the moment this mass is completely transmuted; b) number of reprocessing cycles n rep - effective number of reprocessing cycles a mass of loaded MA has to undergo before being completely transmuted. Some of MA-burners' types have been analyzed from the point of view of these parameters. It turned out that all of them have the value of parameters too high from the practical point of view. It appears that some new approaches to MA-burner's design have to be used to significantly reduce the value of these parameters in order to make the large-scale MA transmutation process practically reasonable. Some of such approaches are proposed and their potential efficiency is discussed. (authors)

  12. CFD optimization of a pellet burner

    Directory of Open Access Journals (Sweden)

    Westerlund Lars B.

    2012-01-01

    Full Text Available Increased capacity of computers has made CFD technology attractive for the design of different apparatuses. Optimization of a pellet burner using CFD was investigated in this paper. To make the design tool work fast, an approach with only mixing of gases was simulated. Other important phenomena such as chemical reactions were omitted in order to speed up the design process. The original design of the burner gave unsatisfactory performance. The optimized design achieved from simulation was validated and the results show a significant improvement. The power output increased and the emission of unburned species decreased but could be further reduced. The contact time between combustion gases and secondary air was probably too short. An increased contact time in high temperature conditions would possibly improve the design further.

  13. A new scaling methodology for NO(x) emissions performance of gas burners and furnaces

    Science.gov (United States)

    Hsieh, Tse-Chih

    1997-11-01

    A general burner and furnace scaling methodology is presented, together with the resulting scaling model for NOsb{x} emissions performance of a broad class of swirl-stabilized industrial gas burners. The model is based on results from a set of novel burner scaling experiments on a generic gas burner and furnace design at five different scales having near-uniform geometric, aerodynamic, and thermal similarity and uniform measurement protocols. These provide the first NOsb{x} scaling data over the range of thermal scales from 30 kW to 12 MW, including input-output measurements as well as detailed in-flame measurements of NO, NOsb{x}, CO, Osb2, unburned hydrocarbons, temperature, and velocities at each scale. The in-flame measurements allow identification of key sources of NOsb{x} production. The underlying physics of these NOsb{x} sources lead to scaling laws for their respective contributions to the overall NOsb{x} emissions performance. It is found that the relative importance of each source depends on the burner scale and operating conditions. Simple furnace residence time scaling is shown to be largely irrelevant, with NOsb{x} emissions instead being largely controlled by scaling of the near-burner region. The scalings for these NOsb{x} sources are combined in a comprehensive scaling model for NOsb{x} emission performance. Results from the scaling model show good agreement with experimental data at all burner scales and over the entire range of turndown, staging, preheat, and excess air dilution, with correlations generally exceeding 90%. The scaling model permits design trade-off assessments for a broad class of burners and furnaces, and allows performance of full industrial scale burners and furnaces of this type to be inferred from results of small scale tests.

  14. Effect of fuel volatility on performance of tail-pipe burner

    Science.gov (United States)

    Barson, Zelmar; Sargent, Arthur F , Jr

    1951-01-01

    Fuels having Reid vapor pressures of 6.3 and 1.0 pounds per square inch were investigated in a tail-pipe burner on an axial-flow-type turbojet engine at a simulated flight Mach number of 0.6 and altitudes from 20,000 to 45,000 feet. With the burner configuration used in this investigation, having a mixing length of only 8 inches between the fuel manifold and the flame holder, the low-vapor-pressure fuel gave lower combustion efficiency at a given tail-pipe fuel-air ratio. Because the exhaust-nozzle area was fixed, the lower efficiency resulted in lower thrust and higher specific fuel consumption. The maximum altitude at which the burner would operate was practically unaffected by the change in fuel volatility.

  15. The influence of burner material properties on the acoustical transfer function of radiant surface burners

    NARCIS (Netherlands)

    Schreel, K.R.A.M.; Tillaart, van den E.L.; Goey, de L.P.H.

    2005-01-01

    Modern central heating systems use low NO$_x$ premixed burners with a largemodulation range. This can lead to noise problems which cannot be solved viatrial and error, but need accurate modelling. An acoustical analysis as part ofthe design phase can reduce the time-to-market considerably, but the

  16. FIELD EVALUATION OF LOW-EMISSION COAL BURNER TECHNOLOGY ON UTILITY BOILERS VOLUME III. FIELD EVALUATIONS

    Science.gov (United States)

    The report gives results of field tests conducted to determine the emission characteristics of a Babcock and Wilcox Circular burner and Dual Register burner (DRB). The field tests were performed at two utility boilers, generally comparable in design and size except for the burner...

  17. Development of stoker-burner wood chip combustion systems for the UK market

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    The document makes a case for the development of a design of wood chip stoker-burner more suited to the UK than those currently imported from Sweden and Finland. The differences would centre on market conditions, performance and cost-effectiveness and the devices would be manufactured or part-manufactured in the UK. Econergy Limited was contracted by the DTI as part of its Sustainable Energy Programmes to design and construct an operational prototype stoker-burner rated at 120 kWth. A test rig was built to: (i) study modified burner heads and (ii) develop control hardware and a control strategy. Both (i) and (ii) are described. Tests brought about an increase in performance of the burner head and its wet wood performance. It was considered that further improvements are achievable and six areas for future study were suggested.

  18. MA-burners efficiency parameters allowing for the duration of transmutation process

    Energy Technology Data Exchange (ETDEWEB)

    Gulevich, A.; Zemskov, E. [Institute of Physics and Power Engineering, Bondarenko Square 1, Obninsk, Kaluga Region 249020 (Russian Federation); Kalugin, A.; Ponomarev, L. [Russian Research Center ' ' Kurchatov Institute' ' Kurchatov Square 1, Moscow 123182 (Russian Federation); Seliverstov, V. [Institute of Theoretical and Experimental Physics ul.B. Cheremushkinskaya 25, Moscow 117259 (Russian Federation); Seregin, M. [Russian Research Institute of Chemical Technology Kashirskoe Shosse 33, Moscow 115230 (Russian Federation)

    2010-07-01

    Transmutation of minor actinides (MA) means their transforming into the fission products. Usually, MA-burner's transmutation efficiency is characterized by the static parameters only, such as the number of neutrons absorbed and the rate of MA feeding. However, the proper characterization of MA-burner's efficiency additionally requires the consideration of parameters allowing for the duration of the MA transmutation process. Two parameters of that kind are proposed: a) transmutation time {tau} - mean time period from the moment a mass of MA is loaded into the burner's fuel cycle to be transmuted to the moment this mass is completely transmuted; b) number of reprocessing cycles n{sub rep} - effective number of reprocessing cycles a mass of loaded MA has to undergo before being completely transmuted. Some of MA-burners' types have been analyzed from the point of view of these parameters. It turned out that all of them have the value of parameters too high from the practical point of view. It appears that some new approaches to MA-burner's design have to be used to significantly reduce the value of these parameters in order to make the large-scale MA transmutation process practically reasonable. Some of such approaches are proposed and their potential efficiency is discussed. (authors)

  19. CFD simulations on marine burner flames

    DEFF Research Database (Denmark)

    Cafaggi, Giovanni; Jensen, Peter Arendt; Glarborg, Peter

    The marine industry is changing with new demands concerning high energy efficiency, fuel flexibility and lower emissions of NOX and SOX. A collaboration between the company Alfa Laval and Technical University of Denmark has been established to support the development of the next generation...... of marine burners. The resulting auxiliary boilers shall be compact and able to operate with different fuel types, while reducing NOX emissions. The specific boiler object of this study uses a swirl stabilized liquid fuel burner, with a pressure swirl spill-return atomizer (Fig.1). The combustion chamber...... is enclosed in a water jacket used for water heating and evaporation, and a convective heat exchanger at the furnace outlet super-heats the steam. The purpose of the present study is to gather detailed knowledge about the influence of fuel spray conditions on marine utility boiler flames. The main goal...

  20. Incineration of ion exchange resins using concentric burners

    International Nuclear Information System (INIS)

    Fukasawa, T.; Chino, K.; Kawamura, F.; Kuriyama, O.; Yusa, H.

    1985-01-01

    A new incineration method, using concentric burners, is studied to reduce the volume of spent ion exchange resins generated from nuclear power plants. Resins are ejected into the center of a propane-oxygen flame and burned within it. The flame length is theoretically evaluated by the diffusion-dominant model. By reforming the burner shape, flame length can be reduced by one-half. The decomposition ratio decreases with larger resin diameters due to the loss of unburned resin from the flame. A flame guide tube is adapted to increase resin holding time in the flame, which improves the decomposition ratio to over 98 wt%

  1. BURNER RIG TESTING OF A500 C/SiC

    Science.gov (United States)

    2018-03-17

    AFRL-RX-WP-TR-2018-0071 BURNER RIG TESTING OF A500® C /SiC Larry P. Zawada Universal Technology Corporation Jennifer Pierce UDRI...TITLE AND SUBTITLE BURNER RIG TESTING OF A500® C /SiC 5a. CONTRACT NUMBER In-House 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62102F 6...test program characterized the durability behavior of A500® C /SiC ceramic matrix composite material at room and elevated temperature. Specimens were

  2. Process development report: 0.20-m secondary burner system

    International Nuclear Information System (INIS)

    Rickman, W.S.

    1977-09-01

    HTGR fuel reprocessing consists of crushing the spent fuel elements to a size suitable for burning in a fluidized bed to remove excess graphite; separating, crushing, and reburning the fuel particles to remove the remainder of the burnable carbon; dissolution and separation of the particles from insoluble materials; and solvent extraction separation of the dissolved uranium and thorium. Burning the crushed fuel particles is accomplished in a secondary burner. This is a batch fluidized-bed reactor with in-vessel, off-gas filtration. Process heat is provided by an induction heater. This report documents operational tests performed on a commercial size 0.20-m secondary burner using crushed Fort St. Vrain type TRISO fuel particles. Analysis of a parametric study of burner process variables led to recommending lower bed superficial velocity (0.8 m/s), lower ignition temperature (600 0 C), lower fluid bed operating temperature (850 0 C), lower filter blowback frequency (1 cycle/minute), and a lower fluid bed superficial velocity during final bed burnout

  3. Development of combined low-emissions burner devices for low-power boilers

    Science.gov (United States)

    Roslyakov, P. V.; Proskurin, Yu. V.; Khokhlov, D. A.

    2017-08-01

    Low-power water boilers are widely used for autonomous heat supply in various industries. Firetube and water-tube boilers of domestic and foreign manufacturers are widely represented on the Russian market. However, even Russian boilers are supplied with licensed foreign burner devices, which reduce their competitiveness and complicate operating conditions. A task of developing efficient domestic low-emissions burner devices for low-power boilers is quite acute. A characteristic property of ignition and fuel combustion in such boilers is their flowing in constrained conditions due to small dimensions of combustion chambers and flame tubes. These processes differ significantly from those in open combustion chambers of high-duty power boilers, and they have not been sufficiently studied yet. The goals of this paper are studying the processes of ignition and combustion of gaseous and liquid fuels, heat and mass transfer and NO x emissions in constrained conditions, and the development of a modern combined low-emissions 2.2 MW burner device that provides efficient fuel combustion. A burner device computer model is developed and numerical studies of its operation on different types of fuel in a working load range from 40 to 100% of the nominal are carried out. The main features of ignition and combustion of gaseous and liquid fuels in constrained conditions of the flame tube at nominal and decreased loads are determined, which differ fundamentally from the similar processes in steam boiler furnaces. The influence of the burner devices design and operating conditions on the fuel underburning and NO x formation is determined. Based on the results of the design studies, a design of the new combined low-emissions burner device is proposed, which has several advantages over the prototype.

  4. Operational limits of recuperative low NO{sub x}-burners using low calorific gas qualities; Einsatzgrenzen rekuperativer Low NO{sub x}-Brenner im Betrieb mit niederkalorischen Gasen

    Energy Technology Data Exchange (ETDEWEB)

    Moentmann, Dirk; Kleingries, Mirko; Pohland vom Schloss, Heide; Lucka, Klaus [OWI Oel-Waerme-Institut GmbH, An-Institut der RWTH, Aachen (Germany)

    2011-06-15

    The by products of several industrial processes are gases with lower calorific value. Rising energy prices make them a focus of interest for thermal utilization. The combuston of low calorific value gases is demanding with respect to the combustion process. The chemical composition varies depending on the application and process flow. A stable combustion has to be ensured at any time in spite of fluctuating properties like calorific value, wobbe index, flame temperature etc. Corrosive components may induce degradation of sealing materials employed in devices of the burner equipment like shut off valves. Within this research project of the research association 'Forschungsgemeinschaft Industrieofenbau (FOGI)' the operation and ignition behaviour of three commercial recuperator burners was investigated under operation with low calorific gases. It is demonstrated that these burners can basically be deployed under certain conditions. (orig.)

  5. Use of 70 MeV proton beam for medical applications at INFN-LNS: CATANA project

    International Nuclear Information System (INIS)

    Sabini, M.G.; Cirrone, G.A.P.; Barone Tonghi, L.; Cuttone, G.; Romeo, N.; Rovelli, A.; Bartolotta, A.; Brai, M.; Teri, G.; Nigro, S. Lo; Marano, F.; Nicoletti, G. A.; Reibaldi, A.; Privitera, G.; Salamone, V.; Raffaele, L.

    2000-01-01

    The project CATANA (Centro di Adro Terapia ed Applicazioni Nucleari Avanzate) is a collaboration between the INFN-Laboratori Nazionali del Sud (LNS), Physics Department, Ophthalmology Institute and Radiology Institute of the Catania University and CSFNSM Catania. The main goal of CATANA is the study and the application of protontherapy for the treatment of shallow tumors (4 cm max) like uveal melanomas and subfoveal macular degenerations

  6. Use of 70 MeV Proton Beam for Medical Applications at INFN-LNS: CATANA Project

    International Nuclear Information System (INIS)

    Sabini, M.G.; Cirrone, G.A.P.; Barone Tonghi, L.; Bartolotta, A.; Brai, M.; Cuttone, G.; Lo Nigro, S.; Marano, F.; Nicoletti, G.A.; Privitera, G.; Raffaele, L.; Reibaldi, A.; Romeo, N.; Rovelli, A.; Salamone, V.; Teri, G.

    2000-01-01

    The project CATANA (Centro di AdroTerapia ed Applicazioni Nucleari Avanzate) is a collaboration between the INFN-Laboratori Nazionali del Sud (LNS), Physics Department, Ophthalmology Institute and Radiology Institute of the Catania University and CSFNSM Catania. The main goal of CATANA is the study and the application of proton therapy for the treatment of shallow tumors (4 cm max) like uveal melanomas and subfoveal macular degenerations

  7. Use of 70 MeV proton beam for medical applications at INFN-LNS: CATANA project

    Science.gov (United States)

    Sabini, M. G.; Cirrone, G. A. P.; Tonghi, L. Barone; Bartolotta, A.; Brai, M.; Cuttone, G.; Nigro, S. Lo; Marano, F.; Nicoletti, G. A.; Privitera, G.; Raffaele, L.; Reibaldi, A.; Romeo, N.; Rovelli, A.; Salamone, V.; Teri, G.

    2000-04-01

    The project CATANA (Centro di Adro Terapia ed Applicazioni Nucleari Avanzate) is a collaboration between the INFN-Laboratori Nazionali del Sud (LNS), Physics Department, Ophthalmology Institute and Radiology Institute of the Catania University and CSFNSM Catania. The main goal of CATANA is the study and the application of protontherapy for the treatment of shallow tumors (4 cm max) like uveal melanomas and subfoveal macular degenerations.

  8. Burners. Reduction of nitrogen oxides in combustion: 2. generation of GR LONOxFLAM burner; Les bruleurs. La reduction des oxydes d`azote dans la combustion: bruleur GR LONOxFLAM de 2. generation

    Energy Technology Data Exchange (ETDEWEB)

    Gauthier, J.C. [EGCI Pillard, 13 - Marseille (France)

    1997-12-31

    This paper presents the research work carried out by the French Pillard company in collaboration with Gaz de France for the design of low NO{sub x} burners. The different type of low NO{sub x} burners are presented according to the type of fuel: gas, liquid fuels and fuel oils. The gas burner uses the fuel staging principle and the recirculation of smokes and leads to NO{sub x} emissions lower than 100 mg/Nm{sup 3}. The liquid fuel and fuel oil burners use the separate flames and the smoke self-recirculation methods (fuel-air mixture staging, reduction of flame temperature and of the residence time in flames). (J.S.)

  9. Pollutant emissions reduction and performance optimization of an industrial radiant tube burner

    Energy Technology Data Exchange (ETDEWEB)

    Scribano, Gianfranco; Solero, Giulio; Coghe, Aldo [Dipartimento di Energetica, Politecnico di Milano, via La Masa, 34, 20156 Milano (Italy)

    2006-07-15

    This paper presents the results of an experimental investigation performed upon a single-ended self-recuperative radiant tube burner fuelled by natural gas in the non-premixed mode, which is used in the steel industry for surface treatment. The main goal of the research activity was a systematic investigation of the burner aimed to find the best operating conditions in terms of optimum equivalence ratio, thermal power and lower pollutant emissions. The analysis, which focused on the main parameters influencing the thermal efficiency and pollutant emissions at the exhaust (NO{sub x} and CO), has been carried out for different operating conditions of the burner: input thermal powers from 12.8 up to 18kW and equivalence ratio from 0.5 (very lean flame) to 0.95 (quasi-stoichiometric condition). To significantly reduce pollutant emissions ensuring at the same time the thermal requirements of the heating process, it has been developed a new burner configuration, in which a fraction of the exhaust gases recirculates in the main combustion region through a variable gap between the burner efflux and the inner flame tube. This internal recirculation mechanism (exhaust gases recirculation, EGR) has been favoured through the addition of a pre-combustion chamber terminated by a converging nozzle acting as a mixing/ejector to promote exhaust gas entrainment into the flame tube. The most important result of this solution was a decrease of NO{sub x} emissions at the exhaust of the order of 50% with respect to the original burner geometry, for a wide range of thermal power and equivalence ratio. (author)

  10. Experimental verification of altitude effect over thermal power in an atmospheric burner

    International Nuclear Information System (INIS)

    Amell Arrieta, Andres; Agudelo, John Ramiro; Cortes, Jaime

    1992-01-01

    Colombian national massive gasification plan is carried out in a variety of geographic altitudes ranging from 0 to 2.600 meter. The biggest market is located in the Andinan Region, which is characterized by great urban centres located at high altitudes. Commercial, domestic and industrial applications are characterized by the utilization of appliances using atmospheric burners. The thermal power of these burners is affected by altitude. This paper shows experimental results of thermal power reduction in atmospheric burners due to altitude changes. It was found that thermal power is reduced by 1,5% each 304 meters of altitude

  11. IEN project - Fluidized bed burner

    International Nuclear Information System (INIS)

    1985-08-01

    Due to difficulties inherent to the organic waste storage from laboratories and institutes which use radioactive materials for scientific researches, the Nuclear Facilities Division (DIN/CNEN); elaborated a project for constructing a fluidized burner, in laboratory scale, for burning the low level organic radioactive wastes. The burning system of organic wastes is described. (M.C.K.) [pt

  12. Numerical investigation of a novel burner to combust anode exhaust gases of SOFC stacks

    Directory of Open Access Journals (Sweden)

    Pianko-Oprych Paulina

    2017-09-01

    Full Text Available The aim of the present study was a numerical investigation of the efficiency of the combustion process of a novel concept burner under different operating conditions. The design of the burner was a part of the development process of a complete SOFC based system and a challenging combination of technical requirements to be fulfilled. A Computational Fluid Dynamics model of a non-premixed burner was used to simulate combustion of exhaust gases from the anode region of Solid Oxide Fuel Cell stacks. The species concentrations of the exhaust gases were compared with experimental data and a satisfactory agreement of the conversion of hydrocarbons was obtained. This validates the numerical methodology and also proves applicability of the developed approach that quantitatively characterized the interaction between the exhaust gases and burner geometry for proper combustion modelling. Thus, the proposed CFD approach can be safely used for further numerical optimisation of the burner design.

  13. Development and demonstration of a gas-fired recuperative confined radiant burner (deliverable 42/43). Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-06-01

    The objective of the project was to develop and demonstrate an innovative, efficient, low-pollutant, recuperative gas-fired IR-system (infrared radiation) for industrial processes (hereafter referred to as the CONRAD-system). The CONRAD-system is confined, so flue gases from the combustion can be kept separated from the product. The gas/air mixture to the burner is preheated by means of the flue gas, which increases the radiant efficiency of the CONRAD-system significantly over traditional gas-fired IR burners. During the first phase of the project, the CONRAD-system was designed and developed. The conducted work included a survey on suitable burner materials, modelling of the burner system, basic design of burner construction, control etc., experimental characterisation of several preprototypes and detailed design of the internal heat exchanger in the burner. The result is a cost effective burner system with a documented radiant efficiency up to 66% and low emissions (NO{sub x} and CO) all in accordance with the criteria of success set up at the start of the project. In the second phase of the project, the burner system was established and tested in laboratory and in four selected industrial applications: 1) Drying of coatings on sand cores in the automotive industry. 2) Baking of bread/cake. 3) General purpose painting/powder curing process 4. Curing of powder paint on wood components. The results from the preliminary tests Overe used to optimise the CONRAD-system, before it was applied in the industrial processes and demonstrated. However, the optimised burners manufactured for demonstration suffered from different 'infant failures', which made the installation in an industrial environment very cumbersome, and even impossible in the food industry and the automotive industry. In the latter cases realistic laboratory tests Overe carried out and the established know how reported for use when the burner problems are overcome.(au)

  14. Combustion of solid alternative fuels in the cement kiln burner

    DEFF Research Database (Denmark)

    Nørskov, Linda Kaare

    In the cement industry there is an increasing environmental and financial motivation for substituting conventional fossil fuels with alternative fuels, being biomass or waste derived fuels. However, the introduction of alternative fuels may influence emissions, cement product quality, process...... stability, and process efficiency. Alternative fuel substitution in the calciner unit has reached close to 100% at many cement plants and to further increase the use of alternative fuels rotary kiln substitution must be enhanced. At present, limited systematic knowledge of the alternative fuel combustion...... properties and the influence on the flame formation is available. In this project a scientific approach to increase the fundamental understanding of alternative fuel conversion in the rotary kiln burner is employed through literature studies, experimental combustion characterisation studies, combustion...

  15. Mathematical model of stacked one-sided arrangement of the burners

    Directory of Open Access Journals (Sweden)

    Oraz J.A.

    2017-01-01

    Full Text Available Paper is aimed at computer simulation of the turbulent methane-air combustion in upgraded U-shaped boiler unit. To reduce the temperature in the flame and hence NOx release every burner output was reduced, but the number of the burners was increased. The subject of studying: complex of characteristics with space-time fields in the upgraded steam boiler E-370 with natural circulation. The flare structure, temperature and concentrations were determined computationally.

  16. Thermo-Acoustic Properties of a Burner with Axial Temperature Gradient: Theory and Experiment

    Directory of Open Access Journals (Sweden)

    Béla Kosztin

    2013-03-01

    Full Text Available This paper presents a model for thermo-acoustic effects in a gas turbine combustor. A quarter-wavelength burner with rectangular cross-section has been built and studied from an experimental and theoretical perspective. It has a premixed methane-air flame, which is held by a bluff body, and spans the width of the burner. The flame is compact, i.e. its length is much smaller than that of the burner. The fundamental mode of the burner is unstable; its frequency and pressure distribution have been measured. The complex pressure reflection coefficients at the upstream and downstream end of the burner were also measured. For the theoretical considerations, we divide the burner into three regions (the cold pre-combustion chamber, the flame region and the hot outlet region, and assume one-dimensional acoustic wave propagation in each region. The acoustic pressure and velocity are assumed continuous across the interface between the precombustion chamber and flame region, and across the interface between the flame region and outlet region. The burner ends are modelled by the measured pressure reflection coefficients. The mean temperature is assumed to have the following profile: uniformly cold and uniformly hot in the pre-combustion chamber and outlet region, respectively, and rising continuously from cold to hot in the flame region. For comparison, a discontinuous temperature profile, jumping directly from cold to hot, is also considered. The eigenfrequencies are calculated, and the pressure distribution of the fundamental mode is predicted. There is excellent agreement with the experimental results. The exact profile of the mean temperature in the flame region is found to be unimportant. This study gives us an experimentally validated Green's function, which is a very useful tool for further theoretical studies.

  17. Synthesis of Titanium Dioxide Nanoparticles Using a Double-Slit Curved Wall-Jet Burner

    KAUST Repository

    Ismail, Mohamed; Mansour, Morkous S.; Memon, Nasir K.; Anjum, Dalaver H.; Chung, Suk-Ho

    2016-01-01

    A novel double-slit curved wall-jet (DS-CWJ) burner was proposed and utilized for flame synthesis. This burner was comprised of double curved wall-jet nozzles with coaxial slits; the inner slit was for the delivery of titanium tetraisopropoxide

  18. Microjet burners for molecular-beam sources and combustion studies

    Science.gov (United States)

    Groeger, Wolfgang; Fenn, John B.

    1988-09-01

    A novel microjet burner is described in which combustion is stabilized by a hot wall. The scale is so small that the entire burner flow can be passed through a nozzle only 0.2 mm or less in diameter into an evacuated chamber to form a supersonic free jet with expansion so rapid that all collisional processes in the jet gas are frozen in a microsecond or less. This burner can be used to provide high-temperature source gas for free jet expansion to produce intense beams of internally hot molecules. A more immediate use would seem to be in the analysis of combustion products and perhaps intermediates by various kinds of spectroscopies without some of the perturbation effects encountered in probe sampling of flames and other types of combustion devices. As an example of the latter application of this new tool, we present infrared emission spectra for jet gas obtained from the combustion of oxygen-hydrocarbon mixtures both fuel-rich and fuel-lean operation. In addition, we show results obtained by mass spectrometric analysis of the combustion products.

  19. 40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

    Science.gov (United States)

    2010-07-01

    ... Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam generating units... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Are duct burners and waste heat...

  20. Development, study and use of GN type high-speed burners

    Energy Technology Data Exchange (ETDEWEB)

    Pilipenko, R A; Yerinov, A Y

    1981-01-01

    The design of a tunnel high speed gas burner for thermal, tunnel, and annealing furnaces is described. The use of GN type burners and heat treating processes and annealing of articles allows one to attain high uniformity of heating, to reduce fuel consumption, and to simplify the lining. A high degree of (+ or - f/sup 0/C) heating uniformity and significant (up to 30%) fuel saving was obtained in a heat treatment furnace with a roll-out hearth at the Uralkhimmash plant.

  1. Oil fired boiler/solar tank- and natural gas burner/solar tank-units

    DEFF Research Database (Denmark)

    Furbo, Simon; Vejen, Niels Kristian; Frederiksen, Karsten Vinkler

    1999-01-01

    During the last few years new units consisting of a solar tank and either an oil fired boiler or a natural gas burner have been introduced on the Danish market. Three different marketed units - two based on a natural gas burner and one based on an oil fired boiler - have been tested in a heat...

  2. Appraisal of BWR plutonium burners for energy centers

    International Nuclear Information System (INIS)

    Williamson, H.E.

    1976-01-01

    The design of BWR cores with plutonium loadings beyond the self-generation recycle (SGR) level is investigated with regard to their possible role as plutonium burners in a nuclear energy center. Alternative plutonium burner approaches are also examined including the substitution of thorium for uranium as fertile material in the BWR and the use of a high-temperature gas reactor (HTGR) as a plutonium burner. Effects on core design, fuel cycle facility requirements, economics, and actinide residues are considered. Differences in net fissile material consumption among the various plutonium-burning systems examined were small in comparison to uncertainties in HTGR, thorium cycle, and high plutonium-loaded LWR technology. Variation in the actinide content of high-level wastes is not likely to be a significant factor in determining the feasibility of alternate systems of plutonium utilization. It was found that after 10,000 years the toxicity of actinide high-level wastes from the plutonium-burning fuel cycles was less than would have existed if the processed natural ores had not been used for nuclear fuel. The implications of plutonium burning and possible future fuel cycle options on uranium resource conservation are examined in the framework of current ERDA estimates of minable uranium resources

  3. A design of steady state fusion burner

    International Nuclear Information System (INIS)

    Hasegawa, Akira; Hatori, Tadatsugu; Itoh, Kimitaka; Ikuta, Takashi; Kodama, Yuji.

    1975-01-01

    We present a brief design of a steady state fusion burner in which a continuous burning of nuclear fuel may be achieved with output power of a gigawatt. The laser fusion is proposed to ignite the fuel. (auth.)

  4. Application of roof radiant burners in large pusher-type furnaces

    Directory of Open Access Journals (Sweden)

    A. Varga

    2009-07-01

    Full Text Available The paper deals with the application of roof flat-flame burners in the pusher-type steel slab reheating furnaces, after furnace reconstruction and replacement of conventional torch burners, with the objective to increase the efficiency of radiative heat transfer from the refractory roof to the charge. Based on observations and on measurements of the construction and process parameters under operating conditions, the advantages and disadvantages of indirectly oriented radiant heat transfer are analysed in relation to the heat transfer in classically fired furnaces.

  5. Flame stability and emission characteristics of turbulent LPG IDF in a backstep burner

    Energy Technology Data Exchange (ETDEWEB)

    S. Mahesh; D.P. Mishra [Indian Institute of Technology, Kanpur (India). Combustion Laboratory, Department of Aerospace Engineering

    2008-09-15

    The stability characteristics and emissions from turbulent LPG inverse diffusion flame (IDF) in a backstep burner are reported in this paper. The blow-off velocity of turbulent LPG IDF is observed to increase monotonically with fuel jet velocity. In contrast to normal diffusion flames (NDF), the flame in the present IDF burner gets blown out without getting lifted-off from the burner surface. The soot free length fraction, SFLF, defined as the ratio of visible premixing length, H{sub p}, to visible flame length, H{sub f}, is used for qualitative estimation of soot reduction in this IDF burner. The SFLF is found to increase with central air jet velocity indicating the occurrence of extended premixing zone in the vicinity of flame base. Interestingly, the soot free length fraction (SFLF) is found to be correlated well with the newly devised parameter, global momentum ratio. The peak value of EINOX happens to occur closer to stoichiometric overall equivalence ratio. 16 refs., 9 figs.

  6. Burning low volatile fuel in tangentially fired furnaces with fuel rich/lean burners

    International Nuclear Information System (INIS)

    Wei Xiaolin; Xu Tongmo; Hui Shien

    2004-01-01

    Pulverized coal combustion in tangentially fired furnaces with fuel rich/lean burners was investigated for three low volatile coals. The burners were operated under the conditions with varied value N d , which means the ratio of coal concentration of the fuel rich stream to that of the fuel lean stream. The wall temperature distributions in various positions were measured and analyzed. The carbon content in the char and NO x emission were detected under various conditions. The new burners with fuel rich/lean streams were utilized in a thermal power station to burn low volatile coal. The results show that the N d value has significant influences on the distributions of temperature and char burnout. There exists an optimal N d value under which the carbon content in the char and the NO x emission is relatively low. The coal ignition and NO x emission in the utilized power station are improved after retrofitting the burners

  7. Research and Development of Natural Draft Ultra-Low Emissions Burners for Gas Appliances

    Energy Technology Data Exchange (ETDEWEB)

    Therkelsen, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cheng, Robert [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sholes, Darren [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-08-31

    Combustion systems used in residential and commercial cooking appliances must be robust and easy to use while meeting air quality standards. Current air quality standards for cooking appliances are far greater than other stationary combustion equipment. By developing an advanced low emission combustion system for cooking appliances, the air quality impacts from these devices can be reduced. This project adapted the Lawrence Berkeley National Laboratory (LBNL) Ring-Stabilizer Burner combustion technology for residential and commercial natural gas fired cooking appliances (such as ovens, ranges, and cooktops). LBNL originally developed the Ring-Stabilizer Burner for a NASA funded microgravity experiment. This natural draft combustion technology reduces NOx emissions significantly below current SCAQMD emissions standards without post combustion treatment. Additionally, the Ring-Stabilizer Burner technology does not require the assistance of a blower to achieve an ultra-low emission lean premix flame. The research team evaluated the Ring-Stabilizer Burner and fabricated the most promising designs based on their emissions and turndown.

  8. Combustion characteristics of porous media burners under various back pressures: An experimental study

    Directory of Open Access Journals (Sweden)

    Xuemei Zhang

    2017-07-01

    Full Text Available The porous media combustion technology is an effective solution to stable combustion and clean utilization of low heating value gas. For observing the combustion characteristics of porous media burners under various back pressures, investigating flame stability and figuring out the distribution laws of combustion gas flow and resistance loss, so as to achieve an optimized design and efficient operation of the devices, a bench of foamed ceramics porous media combustion devices was thus set up to test the cold-state resistance and hot-state combustion characteristic of burners in working conditions without back pressures and with two different back pressures. The following results are achieved from this experimental study. (1 The strong thermal reflux of porous media can preheat the premixed air effectively, so the flame can be kept stable easily, the combustion equivalent ratio of porous media burners is lower than that of traditional burners, and its pollutant content of flue gas is much lower than the national standard value. (2 The friction coefficient of foamed ceramics decreases with the increase of air flow rate, and its decreasing rate slows down gradually. (3 When the flow rate of air is low, viscosity is the dominant flow resistance, and the friction coefficient is in an inverse relation with the flow rate. (4 As the flow rate of air increases, inertia is the dominant flow resistance, and the friction coefficient is mainly influenced by the roughness and cracks of foamed ceramics. (5 After the introduction of secondary air, the minimum equivalent ratio of porous media burners gets much lower and its range of equivalent ratio is much larger than that of traditional burners.

  9. Comparison calculations for an accelerator-driven minor actinide burner

    International Nuclear Information System (INIS)

    2002-01-01

    International interest in accelerator-driven systems (ADS) has recently been increasing in view of the important role that these systems may play as efficient minor actinide and long-lived fission-product (LLFP) burners and/or energy producers with an enhanced safety potential. However, the current methods of analysis and nuclear data for minor actinide and LLFP burners are not as well established as those for conventionally fuelled reactor systems. Hence, in 1999, the OECD/NEA Nuclear Science Committee organised a benchmark exercise for an accelerator-driven minor actinide burner to check the performances of reactor codes and nuclear data for ADS with unconventional fuel and coolant. The benchmark model was a lead-bismuth-cooled subcritical system driven by a beam of 1 GeV protons. This report provides an analysis of the results supplied by seven participants from eight countries. The analysis reveals significant differences in important neutronic parameters, indicating a need for further investigation of the nuclear data, especially minor actinide data, as well as the calculation methods. This report will be of particular interest to reactor physicists and nuclear data evaluators developing nuclear systems for nuclear waste management. (authors)

  10. Interim results: fines recycle testing using the 4-inch diameter primary graphite burner

    International Nuclear Information System (INIS)

    Palmer, W.B.

    1975-05-01

    The results of twenty-two HTGR primary burner runs in which graphite fines were recycled pneumatically to the 4-inch diameter pilot-plant primary fluidized-bed burner are described. The result of the tests showed that zero fines accumulation can easily be achieved while operating at plant equivalent burn rates. (U.S.)

  11. 3-DIMENSIONAL SIMULATION AND FEASIBILITY STUDY OF BIOMASS/COAL CO-COMBUSTION BURNER

    Directory of Open Access Journals (Sweden)

    Nataliya DUNAYEVSKA

    2017-06-01

    Full Text Available Combustion of solid biomass mixed with coal in existing boilers not only reduces harmful emissions, but also allows diversifying the available fuel base. Such technology allows to implement the efficient use of food industry solid wastes, which otherwise would be dumped in piles, and thus produce harmful environmental impact. The geometrical models of research reactor and a burner thermal preprocessing of pulverized coal were developed and calculational meshes were generated. The geometrical model of the VGP-100Vpresents only fluid domain whereas the effect of cooled walls was substituted by the equivalent biudary conditions deruved on the basis of direct experimentation. The model of the VGP-100V allowed accounting for the specifics of radiative heat transfer by comparison of experimental thermo-couple measurements to the simulated by the model one. A model has been developed allowing the determination of actual temperatures of combustion gases flow based upon the reading of unsheathed thermo-couples by taking into account the reradiation of the thermo-couple beads to the channel walls. Based on the ANSYS 3-D process model in the burner of the Trypilska Thermal Power Plant (TPP for the combustion of low-reactive coal with the thermochemical preparation of the design of an actual burner has been developed. On the basis of the experimental studies of the actual burner and the above-mentioned CFD calculations, the burner draft of the 65 MW for TPP-210A boiler aimed at the implementation of biomass-coal co-combustion was designed.

  12. Lipid based nutrient supplements (LNS) for treatment of children (6 months to 59 months) with moderate acute malnutrition (MAM): A systematic review

    Science.gov (United States)

    Pena-Rosas, Juan Pablo; Boy-Mena, Evelyn; Sachdev, Harshpal S.

    2017-01-01

    Background Moderate acute malnutrition is a major public health problem affecting children from low- and middle-income countries. Lipid nutrient supplements have been proposed as a nutritional intervention for its treatment. Objectives To evaluate the effectiveness and safety of LNS for the treatment of MAM in infants and children 6 to 59 months of age. Study design Systematic review of randomized-controlled trials and controlled before-after studies. Results Data from nine trials showed that use of LNS, in comparison to specially formulated foods, improved the recovery rate (RR 1.08; 95% CI 1.02–1.14, 8 RCTs, 8934 participants, low quality evidence); decreased the chances of no recovery (RR 0.70; 95% CI 0.58–0.85, 7 RCTs, 8364 participants, low quality evidence) and the risk of deterioration into severe acute malnutrition (RR 0.87; 95% CI 0.73–1.03, 6 RCTs, 6788 participants, low quality evidence). There was little impact on mortality (RR 0.94, 95% CI 0.54–1.52, 8 RCTs, 8364 participants, very-low- quality evidence) or default rate (RR 1.32; 95% CI 0.73–2.4, 7 studies, 7570 participants, low quality evidence). There was improvement in weight gain, weight-for-height z-scores, height-for-age z-scores and mid-upper arm circumference. Subset analyses suggested higher recovery rates with greater amount of calories provided and with ready-to-use therapeutic foods, in comparison to ready-to-use supplementary foods. One study comparing LNS with nutritional counselling (very low quality evidence) showed higher chance of recovery, lower risk of deteriorating into severe acute malnutrition and lower default rate, with no impact on mortality, and no recovery. Conclusions Evidence restricted to the African regions suggests that LNS may be slightly more effective than specially formulated fortified foods or nutritional counselling in recovery from MAM, lowering the risk of deterioration into SAM, and improving weight gain with little impact on mortality or default

  13. Design and evaluation of a porous burner for the mitigation of anthropogenic methane emissions.

    Science.gov (United States)

    Wood, Susie; Fletcher, David F; Joseph, Stephen D; Dawson, Adrian; Harris, Andrew T

    2009-12-15

    Methane constitutes 15% of total global anthropogenic greenhouse gas emissions. The mitigation of these emissions could have a significant near-term effect on slowing global warming, and recovering and burning the methane would allow a wasted energy resource to be exploited. The typically low and fluctuating energy content of the emission streams makes combustion difficult; however porous burners-an advanced combustion technology capable of burning low-calorific value fuels below the conventional flammability limit-are one possible mitigation solution. Here we discuss a pilot-scale porous burner designed for this purpose. The burner comprises a cylindrical combustion chamber filled with a porous bed of alumina saddles, combined with an arrangement of heat exchanger tubes for preheating the incoming emission stream. A computational fluid dynamics model was developed to aid in the design process. Results illustrating the burner's stable operating range and behavior are presented: stable ultralean combustion is demonstrated at natural gas concentrations as low as 2.3 vol%, with transient combustion at concentrations down to 1.1 vol%; the system is comparatively stable to perturbations in the operating conditions, and emissions of both carbon monoxide and unburned hydrocarbons are negligible. Based on this pilot-scale demonstration, porous burners show potential as a methane mitigation technology.

  14. Study and mathematical model of ultra-low gas burner

    International Nuclear Information System (INIS)

    Gueorguieva, A.

    2001-01-01

    The main objective of this project is prediction and reduction of NOx and CO 2 emissions under levels recommended from European standards for gas combustion processes. A mathematical model of burner and combustion chamber is developed based on interacting fluid dynamics processes: turbulent flow, gas phase chemical reactions, heat and radiation transfer The NOx prediction model for prompt and thermal NOx is developed. The validation of CFD (Computer fluid-dynamics) simulations corresponds to 5 MWI burner type - TEA, installed on CASPER boiler. This burner is three-stream air distribution burner with swirl effect, designed by ENEL to meet future NOx emission standards. For performing combustion computer modelling, FLUENT CFD code is preferred, because of its capabilities to provide accurately description of large number of rapid interacting processes: turbulent flow, phase chemical reactions and heat transfer and for its possibilities to present wide range of calculation and graphical output reporting data The computational tool used in this study is FLUENT version 5.4.1, installed on fs 8200 UNIX systems The work includes: study the effectiveness of low-NOx concepts and understand the impact of combustion and swirl air distribution and flue gas recirculation on peak flame temperatures, flame structure and fuel/air mixing. A finite rate combustion model: Eddy-Dissipation (Magnussen-Hjertager) Chemical Model for 1, 2 step Chemical reactions of bi-dimensional (2D) grid is developed along with NOx and CO 2 predictions. The experimental part of the project consists of participation at combustion tests on experimental facilities located in Livorno. The results of the experiments are used, to obtain better vision for combustion process on small-scaled design and to collect the necessary input data for further Fluent simulations

  15. Passive safety design characteristics of the KALIMER-600 burner reactor

    International Nuclear Information System (INIS)

    Kwon, Young-Min; Jeong, Hae-Yong; Cho, Chung-Ho; Ha, Ki-Seok; Kim, Sang-Ji

    2009-01-01

    The Korea Atomic Energy Research Institute (KAERI) has recently studied several burner core designs for a transuranics (TRU) transmutation based on the breakeven core geometry of KALIMER-600. The KALIMER-600 is a net electrical rating of 600MWe, sodium-cooled, metallic-fueled, pool-type reactor. For the burner core concept selected for the present analysis, the smearing fractions of the fuel rods in three fuel zones are changed while maintaining the cladding outer diameter and cladding thickness. The resulting fuel slug smearing fractions of the inner, middle, and outer core zones are 36%, 40%, and 48%, respectively. The TRU conversion ratio is 0.57 and the TRU enrichment of the driver fuel is set to 30.0 w/o because of the current practical limitation of the U-TRU-10%Zr metal fuel database. The purpose of this paper is to evaluate the safety performance characteristics provided by the passive safety design features in the KALIMER-600 burner reactor by using a system-wide safety analysis code. The present scoping analysis focuses on an assessment of the enhanced safety design features that provide passive and self-regulating responses to transient conditions and an evaluation of the safety margin during unprotected overpower, unprotected loss of flow, and unprotected loss of heat sink events. The analysis results show that the KALIMER-600 burner reactor provides larger safety margins with respect to the sodium boiling, fuel rod integrity, and structural integrity. The overall inherent safety can be enhanced by accounting for the reactivity feedback mechanisms in the design process. (author)

  16. Reduction of lns-1 gene expression and tissue insulin levels in n5-STZ rats

    Directory of Open Access Journals (Sweden)

    Belinda Vargas Guerrero

    2013-01-01

    Full Text Available Objective: The high global incidence of type 2 diabetes has challenged researchers to establish animal models that resemble the chronic stage observed in type 2 diabetes patients. One such model is induced by neonatal streptozotocin (n-STZ administration to rat pups at 0, 2, or 5 days after birth. In this study, we assessed lns-1 gene expression and tissue insulin levels as well as serum concentration of glucose and insulin, insulin resistance, and histological changes of the islets of Langerhans in n5-STZ rats after 20-weeks post-induction. Methods: Wistar rat pups were randomly distributed into a control group and a streptozotocin-induced group. Experimental induction involved a single intraperitoneal injection of streptozotocin (150 mg/kg into neonates at five days after birth. Results: At 20 weeks post-induction, streptozotocin-induced rats exhibited increased serum glucose levels, reduced serum insulin levels, impaired glucose metabolism and insulin resistance compared to control rats. Histologically, streptozotocin-induced rats exhibited atrophic islets, vacuolization, and significantly fewer insulin-positive cells. lns-1 gene expression was significantly decreased in n5-STZ rats in comparison to the control group. Conclusion: Our findings support that the n5-STZ model 20 weeks post-induction represents an appropriate experimental tool to study T2D and to evaluate novel therapeutic agents and targets that involve insulin gene expression and secretion, as well as complications caused by chronic diabetes.

  17. Experimental investigation of combustion instabilities in lean swirl-stabilized partially-premixed flames in single- and multiple-burner setup

    Directory of Open Access Journals (Sweden)

    Christian Kraus

    2016-03-01

    Full Text Available In the present work, combustion instabilities of a modular combustor are investigated. The combustor operates with partially premixed, swirl-stabilized flames and can be operated in single- and different multiple-burner setups. The design parameters of the combustor prevent large-scale flame–flame interactions in the multiple-burner arrangements. The objective is to investigate how the interaction of the swirl jets affects the thermoacoustic stability of the combustor. Results of measurements of pressure oscillations and high-speed OH*-chemiluminescence imaging for the single-burner setup and two multiple-burner setups are discussed. Additionally, results of investigations with different flame characteristics are presented. These are achieved by varying the ratio of the mass flow rates through the swirlers of the double-concentric swirl nozzle. Several unstable modes with high pressure amplitudes are observed in the single-burner setup as well as in the multiple-burner setups. Numerical studies of the acoustic behavior of the combustor setups were performed that indicate that the different geometries show similar acoustic behaviors. The results lead to the conclusion that the interaction of the swirl jets in the multiple-burner setups affects the thermoacoustic response spectrum of the flame even in the absence of large-scale flame–flame interactions. Based on the findings in earlier studies, it is concluded that the differences in the flame response characteristics are induced by the reduction of the swirl intensity in the multiple-burner arrangements, which is caused by the exchange of momentum between the adjacent swirl jets.

  18. Optimal Switching Control of Burner Setting for a Compact Marine Boiler Design

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Maciejowski, Jan M.

    2010-01-01

    This paper discusses optimal control strategies for switching between different burner modes in a novel compact  marine boiler design. The ideal behaviour is defined in a performance index the minimisation of which defines an ideal trade-off between deviations in boiler pressure and water level...... approach is based on a generalisation of hysteresis control. The strategies are verified on a simulation model of the compact marine boiler for control of low/high burner load switches.  ...

  19. Duct burners in heat recovery system for cogeneration and captive power plants

    International Nuclear Information System (INIS)

    Majumdar, J.

    1992-01-01

    Our oil explorations both onshore and offshore have thrown open bright prospects of cogeneration by using natural gas in gas turbine power plants with heat recovery units. Both for co-gen and combined cycle systems, supplementary firing of GT exhaust gas is normally required. Hence, duct burners have significant role for effective contribution towards of efficacy of heat recovery system for gas turbine exhaust gas. This article details on various aspects of duct burners in heat recovery systems. (author)

  20. On Bunsen Burners, Bacteria and the Bible

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 2. On Bunsen Burners, Bacteria and the Bible. Milind Watve. Classroom Volume 1 Issue 2 February 1996 pp 84-89. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/02/0084-0089 ...

  1. Preliminary Results on the Effects of Distributed Aluminum Combustion Upon Acoustic Growth Rates in a Rijke Burner

    OpenAIRE

    Newbold, Brian R.

    1998-01-01

    Distributed particle combustion in solid propellant rocket motors may be a significant cause of acoustic combustion instability. A Rijke burner has been developed as a tool to investigate the phenomenon. Previous improvements and characterization of the upright burner lead to the addition of a particle injection flame. The injector flame increases the burner's acoustic driving by about 10% which is proportional to the injector's additional 2 g/min of gas. Frequency remained fairly constant fo...

  2. LNS users primer for accessing government sites on the ARPA network. [MIT. -->. ANL, BNL, LBL, and New York Univ. Courant Inst

    Energy Technology Data Exchange (ETDEWEB)

    Kannel, M.

    1979-06-01

    This primer was developed as part of the study conducted by the Laboratory for Nuclear Science (LNS) on the feasibility of networks for computer resource sharing. The primer is an instructinal guide for the LNS user who would like to access and use computers at other government sites on the ARPA network. The format is a series of scenarios of actual recorded on-line terminal sessions' showing the novice user how to access the foreign site, obtain help documentation, run a simple program, and transfer files to and from the foreign site. Access to the ARPA network in these scenarios is via Multics or the Massachusetts Institute of Technology Terminal Interface Processor. The foreign government sites accessed are the computing facilities at Argonne National Laboratory, Brookhaven National Laboratory, Lawrence Livermore Laboratory, and New York University Courant Institute. This technique of auditing actual terminal sessions as a teaching aid can be extended to include other computing facilities as well as other networks.

  3. Analyses of the performance of the ASTRID-like TRU burners in regional scenario studies - 5136

    International Nuclear Information System (INIS)

    Vezzoni, B.; Gabrielli, F.; Rineiski, A.

    2015-01-01

    In the past, large Sodium Fast Reactors systems (earlier CAPRA/CADRA, later ESFR and ESFR-like systems) and Accelerator Driven Systems (ADS-EFIT) were considered and extensively studied in Europe for managing MAs/Pu within regional or national scenario studies. After the ASTRID system was proposed in France, ASTRID-like burners could be considered as further options to be investigated. Low conversion ratio (CR) ASTRID-like burner cores (1200 MWth) have been considered at KIT by introducing few modifications with respect to the original French ASTRID design. These modifications allow keeping almost unchanged the main characteristics of the system (e.g. thermal power) and avoiding a strong deterioration of safety parameters (such as sodium void effect) after introduction of large amounts of Pu (more than 20%) and MAs (2-12%) in the fuel. These cores have already been studied at KIT for phase-out scenarios. A constant energy production case, relevant for a European or another regional scenario is considered in the paper. Cases with different shares (from 10 to 30%) of ASTRID-like burners in the nuclear energy fleet are compared. The results show that the ASTRID-like burners allow the use of all TRUs compositions foreseen in the fuel cycle with a proper choice of the MAs to Pu ratios and of the U/TRUs fractions either in phasing-out and on-going nuclear energy utilization conditions. The results show that a mixed fleet composed of 11% burners and 89% ESFR is able to stabilize the MAs in the cycle. The same stabilization is obtained with a fleet composed by 33% burner in combination with LWRs only

  4. The effect of heat transfer on acoustics in burner stabilized flat flames

    OpenAIRE

    Schreel, K.R.A.M.; Tillaart, van den, E.L.; Janssen, R.W.M.; Goey, de, L.P.H.; Vovelle, C.; Lucka, K.

    2003-01-01

    Modern central heating systems use low NO$_x$ premixed burners with a large modulation range. This can lead to noise problems which cannot be solved via trial and error, but need accurate modelling. An acoustic analysis as part of the design phase can reduce the time-to-market considerably, but the acoustic response of the flame is an unknown and complex key-factor. In this study, the influence of the heat transfer between the gas and the burner on the acoustic transfer coefficient is studied...

  5. Polonium release from an ATW burner system with liquid lead-bismuth coolant

    International Nuclear Information System (INIS)

    Li, N.; Yefimov, E.; Pankratov, D.

    1998-04-01

    The authors analyzed polonium release hazards in a conceptual pool-type ATW burner with liquid lead-bismuth eutectic (LBE) coolant. Simplified quantitative models are used based on experiments and real NPP experience. They found little Po contamination outside the burner under normal operating conditions with nominal leakage from the gas system. In sudden gas leak and/or coolant spill accidents, the P contamination level can reach above the regulation limit but short exposure would not lead to severe health consequences. They are evaluating and developing mitigation methods

  6. A NEW DOUBLE-SLIT CURVED WALL-JET (CWJ) BURNER FOR STABILIZING TURBULENT PREMIXED AND NON-PREMIXED FLAMES

    KAUST Repository

    Mansour, Morkous S.

    2015-06-30

    A novel double-slit curved wall-jet (CWJ) burner was proposed and employed, which utilizes the Coanda effect by supplying fuel and air as annular-inward jets over a curved surface. We investigated the stabilization characteristics and structure of methane/air, and propane/air turbulent premixed and non-premixed flames with varying global equivalence ratio, , and Reynolds number, Re. Simultaneous time-resolved measurements of particle image velocimetry and planar laser-induced fluorescence of OH radicals were conducted. The burner showed potential for stable operation for methane flames with relatively large fuel loading and overall rich conditions. These have a non-sooting nature. However, propane flames exhibit stable mode for a wider range of equivalence ratio and Re. Mixing characteristics in the cold flow of non-premixed cases were first examined using acetone fluorescence technique, indicating substantial transport between the fuel and air by exhibiting appreciable premixing conditions.PIV measurements revealed that velocity gradients in the shear layers at the boundaries of the annularjets generate the turbulence, enhanced with the collisions in the interaction jet, IJ,region. Turbulent mean and rms velocities were influenced significantly by Re and high rms turbulent velocities are generated within the recirculation zone improving the flame stabilization in this burner.Premixed and non-premixed flames with high equivalence ratio were found to be more resistant to local extinction and exhibited a more corrugated and folded nature, particularly at high Re. For flames with low equivalence ratio, the processes of local quenching at IJ region and of re-ignition within merged jet region maintained these flames further downstream particularly for non-premixed methane flame, revealing a strong intermittency.

  7. 40 CFR 266.102 - Permit standards for burners.

    Science.gov (United States)

    2010-07-01

    ... or industrial furnace downstream of the combustion zone and prior to release of stack gases to the... MANAGEMENT FACILITIES Hazardous Waste Burned in Boilers and Industrial Furnaces § 266.102 Permit standards for burners. (a) Applicability—(1) General. Owners and operators of boilers and industrial furnaces...

  8. Thermal-hydraulics of actinide burner reactors

    International Nuclear Information System (INIS)

    Takizuka, Takakazu; Mukaiyama, Takehiko; Takano, Hideki; Ogawa, Toru; Osakabe, Masahiro.

    1989-07-01

    As a part of conceptual study of actinide burner reactors, core thermal-hydraulic analyses were conducted for two types of reactor concepts, namely (1) sodium-cooled actinide alloy fuel reactor, and (2) helium-cooled particle-bed reactor, to examine the feasibility of high power-density cores for efficient transmutation of actinides within the maximum allowable temperature limits of fuel and cladding. In addition, calculations were made on cooling of actinide fuel assembly. (author)

  9. Recent progress in plasma modelling at INFN-LNS

    Science.gov (United States)

    Neri, L.; Castro, G.; Torrisi, G.; Galatà, A.; Mascali, D.; Celona, L.; Gammino, S.

    2016-02-01

    At Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS), the development of intense ion and proton sources has been supported by a great deal of work on the modelling of microwave generated plasmas for many years. First, a stationary version of the particle-in-cell code was developed for plasma modelling starting from an iterative strategy adopted for the space charge dominated beam transport simulations. Electromagnetic properties of the plasma and full-waves simulations are now affordable for non-homogenous and non-isotropic magnetized plasma via "cold" approximation. The effects of Coulomb collisions on plasma particles dynamics was implemented with the Langevin formalism, instead of simply applying the Spitzer 90° collisions through a Monte Carlo technique. A wide database of different cross sections related to reactions occurring in a hydrogen plasma was implemented. The next step consists of merging such a variety of approaches for retrieving an "as-a-whole" picture of plasma dynamics in ion sources. The preliminary results will be summarized in the paper for a microwave discharge ion source designed for intense and high quality proton beams production, proton source for European Spallation Source project. Even if the realization of a predictive software including the complete processes involved in plasma formation is still rather far, a better comprehension of the source behavior is possible and so the simulations may support the optimization phase.

  10. CFD simulation of a burner for syngas characterization and experimental validation

    Energy Technology Data Exchange (ETDEWEB)

    Fantozzi, Francesco; Desideri, Umberto [University of Perugia (Italy). Dept. of Industrial Engineering], Emails: fanto@unipg.it, umberto.desideri@unipg.it; D' Amico, Michele [University of Perugia (Italy). Dept. of Energetic Engineering], E-mail: damico@crbnet.it

    2009-07-01

    Biomass and waste are distributed and renewable energy sources that may contribute effectively to sustainability if used on a small and micro scale. This requires the transformation through efficient technologies (gasification, pyrolysis and anaerobic digestion) into a suitable gaseous fuel to use in small internal combustion engines and gas turbines. The characterization of biomass derived syngas during combustion is therefore a key issue to improve the performance of small scale integrated plants because synthesis gas show significant differences with respect to Natural Gas (mixture of gases, low calorific value, hydrogen content, tar and particulate content) that may turn into ignition problems, combustion instabilities, difficulties in emission control and fouling. To this aim a burner for syngas combustion and LHV measurement through mass and energy balance was realized and connected to the rotary-kiln laboratory scale pyrolyzer at the Department of Industrial Engineering of the University of Perugia. A computational fluid dynamics (CFD) simulation of the burner was carried out considering the combustion of propane to investigate temperature and pressure distribution, heat transmission and distribution of the combustion products and by products. The simulation was carried out using the CFD program Star-CD. Before the simulation a geometrical model of the burner was built and the volume of model was subdivided in cells. A sensibility analysis of cells was carried out to estimate the approximation degree of the model. Experimental data about combustion emission were carried out with the propane combustion in the burner, the comparison between numerical results and experimental data was studied to validate the simulation for future works involved with the combustion of treated or raw (syngas with tar) syngas obtained from pyrolysis process. (author)

  11. Characterization of a new Hencken burner with a transition from a reducing-to-oxidizing environment for fundamental coal studies

    Science.gov (United States)

    Adeosun, Adewale; Huang, Qian; Li, Tianxiang; Gopan, Akshay; Wang, Xuebin; Li, Shuiqing; Axelbaum, Richard L.

    2018-02-01

    In pulverized coal burners, coal particles usually transition from a locally reducing environment to an oxidizing environment. The locally reducing environment in the near-burner region is due to a dense region of coal particles undergoing devolatilization. Following this region, the particles move into an oxidizing environment. This "reducing-to-oxidizing" transition can influence combustion processes such as ignition, particulate formation, and char burnout. To understand these processes at a fundamental level, a system is required that mimics such a transition. Hence, we have developed and characterized a two-stage Hencken burner to evaluate the effect of the reducing-to-oxidizing transition and particle-to-particle interaction (which characterizes dense region of coal particles) on ignition and ultrafine aerosol formation. The two-stage Hencken burner allows coal particles to experience a reducing environment followed by a transition to an oxidizing environment. This work presents the results of the design and characterization of the new two-stage Hencken burner and its new coal feeder. In a unique approach to the operation of the flat-flame of the Hencken burner, the flame configurations are operated as either a normal flame or inverse flame. Gas temperatures and oxygen concentrations for the Hencken burner are measured in reducing-to-oxidizing and oxidizing environments. The results show that stable flames with well-controlled conditions, relatively uniform temperatures, and species concentrations can be achieved in both flame configurations. This new Hencken burner provides an effective system for evaluating the effect of the reducing-to-oxidizing transition and particle-to-particle interaction on early-stage processes of coal combustion such as ignition and ultrafine particle formation.

  12. Engineering models for low-NO{sub x} burners

    Energy Technology Data Exchange (ETDEWEB)

    Storm Pedersen, Lars

    1997-08-01

    The present Ph.D. thesis describes a theoretical investigation of NO formation in pulverised coal combustion and an experimental investigation of co-combustion of straw and pulverised coal. The theoretical work has resulted in a simplified mathematical model of a swirling pulverised coal flame able to predict the NO emission and the burnout of coal. In order to simplify the flow pattern of a confined swirling flame, the residence time distribution (RTD) in a swirling pulverised coal flame was determined. This was done by using the solution of a detailed fluid dynamic mathematical model for a 2.2 MW{sub th} and a 12 MW{sub th} pulverised coal flame. From the mathematical solution the RTD was simulated by tracing a number of fluid particles or inert particles. The RTD in the near burner zone was investigated by use of the mathematical model for the 2.2 MW{sub th} and 12 MW{sub th} flame. Results showed that the gas phase in the near burner zone may be approximated as a CSTR and that the mean residence time increased with particle size. In pulverised coal flames, the most important volatile nitrogen component forming NO{sub x} is HCN. To be able to model the nitrogen chemistry in coal flames it is necessary to have an adequate model for HCN oxidation. In order to develop a model for HCN/NH{sub 3}/NO conversion, a systematic reduction of a detailed chemical kinetic model was performed. Based on the simplification of the flow pattern for a swirling flame and the reduced chemistry developed, a chemical engineering model of pulverised coal flame was established. The objectives were to predict the NO emission, the CO emission, and the burnout of char. The effects of co-firing straw and pulverised coal was investigated in a 2.5 MW{sub th} pilot-scale burner and a 250 MW{sub e} utility boiler. In the 2.5 MW{sub th} trial the straw was chopped and fed separately to the burner, whereas in the full-scale experiment the straw was pre-processed as pellets and pulverised with the

  13. PULSE DRYING EXPERIMENT AND BURNER CONSTRUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Robert States

    2006-07-15

    Non steady impingement heat transfer is measured. Impingement heating consumes 130 T-BTU/Yr in paper drying, but is only 25% thermally efficient. Pulse impingement is experimentally shown to enhance heat transfer by 2.8, and may deliver thermal efficiencies near 85%. Experimental results uncovered heat transfer deviations from steady theory and from previous investigators, indicating the need for further study and a better theoretical framework. The pulse burner is described, and its roll in pulse impingement is analyzed.

  14. The influence of near burner region aerodynamics on the formation and emission of nitrogen oxides in a pulverized coal-fired furnace

    International Nuclear Information System (INIS)

    Abbas, T.; Costen, P.; Lockwood, F.C.

    1992-01-01

    This paper reports that detailed measurements have been performed for two distinct pulverized-coal-fired burners in a large-scale laboratory furnace. Comparative in-flame data are archived and include gas temperature, O 2 , CO concentration, and an inventory of stable fuel nitrogen species and solids (HCN, NH 3 , N 2 O, NO, nitrogen release, mass flux, and particle burnout). A significant decrease in the NO concentration in the near burner region and a substantial decrease in the furnace exit values are observed when the central tube from a single annular orifice burner jet (normally the location of a gas or oil burner for light-up purposes) is replaced with a single central orifice burner jet of same cross-sectional area. The latter burner exhibits the delayed combustion phenomena normally associated with a tangentially fired system. The particle burnout remains unaffected due to the longer particles' residence time in the all-important oxygen lean internal recirculation zone

  15. Characterization of a Rijke Burner as a Tool for Studying Distribute Aluminum Combustion

    OpenAIRE

    Newbold, Brian R.

    1996-01-01

    As prelude to the quantitative study of aluminum distributed combustion, the current work has characterized the acoustic growth, frequency, and temperature of a Rijke burner as a function of mass flow rate, gas composition, and geometry. By varying the exhaust temperature profile, the acoustic growth rate can be as much as tripled from the baseline value of approximately 120 s-1• At baseline, the burner operated in the third harmonic mode at a frequency of 1300 Hz, but geometry or temperature...

  16. Combustion Characteristics of Butane Porous Burner for Thermoelectric Power Generation

    Directory of Open Access Journals (Sweden)

    K. F. Mustafa

    2015-01-01

    Full Text Available The present study explores the utilization of a porous burner for thermoelectric power generation. The porous burner was tested with butane gas using two sets of configurations: single layer porcelain and a stacked-up double layer alumina and porcelain. Six PbSnTe thermoelectric (TE modules with a total area of 54 cm2 were attached to the wall of the burner. Fins were also added to the cold side of the TE modules. Fuel-air equivalence ratio was varied between the blowoff and flashback limit and the corresponding temperature, current-voltage, and emissions were recorded. The stacked-up double layer negatively affected the combustion efficiency at an equivalence ratio of 0.20 to 0.42, but single layer porcelain shows diminishing trend in the equivalence ratio of 0.60 to 0.90. The surface temperature of a stacked-up porous media is considerably higher than the single layer. Carbon monoxide emission is independent for both porous media configurations, but moderate reduction was recorded for single layer porcelain at lean fuel-air equivalence ratio. Nitrogen oxides is insensitive in the lean fuel-air equivalence ratio for both configurations, even though slight reduction was observed in the rich region for single layer porcelain. Power output was found to be highly dependent on the temperature gradient.

  17. 40 CFR Appendix A to Part 76 - Phase I Affected Coal-Fired Utility Units With Group 1 or Cell Burner Boilers

    Science.gov (United States)

    2010-07-01

    ... Units With Group 1 or Cell Burner Boilers A Appendix A to Part 76 Protection of Environment... 1 or Cell Burner Boilers Table 1—Phase I Tangentially Fired Units State Plant Unit Operator ALABAMA... Vertically fired boiler. 2 Arch-fired boiler. Table 3—Phase I Cell Burner Technology Units State Plant Unit...

  18. Design process and instrumentation of a low NOx wire-mesh duct burner for micro-cogeneration unit

    Energy Technology Data Exchange (ETDEWEB)

    Ramadan, O.B.; Gauthier, J.E.D. [Carleton Univ., Ottawa, ON (Canada). Dept. of Mechanical and Aerospace Engineering; Hughes, P.M.; Brandon, R. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy Technology Centre

    2007-07-01

    Air pollution and global climate change have become a serious environmental problem leading to increasingly stringent government regulations worldwide. New designs and methods for improving combustion systems to minimize the production of toxic emissions, like nitrogen oxides (NOx) are therefore needed. In order to control smog, acid rain, ozone depletion, and greenhouse-effect warming, a reduction of nitrogen oxide is necessary. One alternative for combined electrical power and heat generation (CHP) are micro-cogeneration units which use a micro-turbine as a prime mover. However, to increase the efficiencies of these units, micro-cogeneration technology still needs to be developed further. This paper described the design process, building, and testing of a new low NOx wire-mesh duct burner (WMDB) for the development of a more efficient micro-cogeneration unit. The primary goal of the study was to develop a practical and simple WMDB, which produces low emissions by using lean-premixed surface combustion concept and its objectives were separated into four phases which were described in this paper. Phase I involved the design and construction of the burner. Phase II involved a qualitative flow visualization study for the duct burner premixer to assist the new design of the burner by introducing an efficient premixer that could be used in this new application. Phase III of this research program involved non-reacting flow modeling on the burner premixer flow field using a commercial computational fluid dynamic model. In phase IV, the reacting flow experimental investigation was performed. It was concluded that the burner successfully increased the quantity and the quality of the heat released from the micro-CHP unit and carbon monoxide emissions of less than 9 ppm were reached. 3 refs., 3 figs.

  19. Emission characteristics and axial flame temperature distribution of producer gas fired premixed burner

    Energy Technology Data Exchange (ETDEWEB)

    Bhoi, P.R. [Department of Mechanical Engineering, L and T-Sargent and Lundy Limited, L and T Energy Centre, Near Chhani Jakat Naka, Baroda 390 002 (India); Channiwala, S.A. [Department of Mechanical Engineering, Sardar Vallabhbhai National Institute of Technology, Deemed University, Ichchhanath, Surat 395 007, Gujarat (India)

    2009-03-15

    This paper presents the emission characteristics and axial flame temperature distribution of producer gas fired premixed burner. The producer gas fired premixed burner of 150 kW capacity was tested on open core throat less down draft gasifier system in the present study. A stable and uniform flame was observed with this burner. An instrumented test set up was developed to evaluate the performance of the burner. The conventional bluff body having blockage ratio of 0.65 was used for flame stabilization. With respect to maximum flame temperature, minimum pressure drop and minimum emissions, a swirl angle of 60 seems to be optimal. The experimental results also showed that the NO{sub x} emissions are inversely proportional to swirl angle and CO emissions are independent of swirl angle. The minimum emission levels of CO and NO{sub x} are observed to be 0.167% and 384 ppm respectively at the swirl angle of 45-60 . The experimental results showed that the maximum axial flame temperature distribution was achieved at A/F ratio of 1.0. The adiabatic flame temperature of 1653 C was calculated theoretically at A/F ratio of 1.0. Experimental results are in tune with theoretical results. It was also concluded that the CO and UHC emissions decreases with increasing A/F ratio while NO{sub x} emissions decreases on either side of A/F ratio of 1.0. (author)

  20. Recent progress in plasma modelling at INFN-LNS

    Energy Technology Data Exchange (ETDEWEB)

    Neri, L., E-mail: neri@lns.infn.it; Castro, G.; Mascali, D.; Celona, L.; Gammino, S. [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Torrisi, G. [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Università Mediterranea di Reggio Calabria, Via Graziella, 89100 Reggio Calabria (Italy); Galatà, A. [INFN-Laboratori Nazionali di Legnaro, Viale dell’Università 2, 35020 Legnaro, Padova (Italy)

    2016-02-15

    At Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS), the development of intense ion and proton sources has been supported by a great deal of work on the modelling of microwave generated plasmas for many years. First, a stationary version of the particle-in-cell code was developed for plasma modelling starting from an iterative strategy adopted for the space charge dominated beam transport simulations. Electromagnetic properties of the plasma and full-waves simulations are now affordable for non-homogenous and non-isotropic magnetized plasma via “cold” approximation. The effects of Coulomb collisions on plasma particles dynamics was implemented with the Langevin formalism, instead of simply applying the Spitzer 90° collisions through a Monte Carlo technique. A wide database of different cross sections related to reactions occurring in a hydrogen plasma was implemented. The next step consists of merging such a variety of approaches for retrieving an “as-a-whole” picture of plasma dynamics in ion sources. The preliminary results will be summarized in the paper for a microwave discharge ion source designed for intense and high quality proton beams production, proton source for European Spallation Source project. Even if the realization of a predictive software including the complete processes involved in plasma formation is still rather far, a better comprehension of the source behavior is possible and so the simulations may support the optimization phase.

  1. Thermionic cogeneration burner assessment study. Third quarterly technical progress report, April-June, 1983

    Energy Technology Data Exchange (ETDEWEB)

    1983-01-01

    The specific tasks of this study are to mathematically model the thermionic cogeneration burner, experimentally confirm the projected energy flows in a thermal mock-up, make a cost estimate of the burner, including manufacturing, installation and maintenance, review industries in general and determine what groups of industries would be able to use the electrical power generated in the process, select one or more industries out of those for an in-depth study, including determination of the performance required for a thermionic cogeneration system to be competitive in that industry. Progress is reported. (WHK)

  2. Fully Premixed Low Emission, High Pressure Multi-Fuel Burner

    Science.gov (United States)

    Nguyen, Quang-Viet (Inventor)

    2012-01-01

    A low-emissions high-pressure multi-fuel burner includes a fuel inlet, for receiving a fuel, an oxidizer inlet, for receiving an oxidizer gas, an injector plate, having a plurality of nozzles that are aligned with premix face of the injector plate, the plurality of nozzles in communication with the fuel and oxidizer inlets and each nozzle providing flow for one of the fuel and the oxidizer gas and an impingement-cooled face, parallel to the premix face of the injector plate and forming a micro-premix chamber between the impingement-cooled face and the in injector face. The fuel and the oxidizer gas are mixed in the micro-premix chamber through impingement-enhanced mixing of flows of the fuel and the oxidizer gas. The burner can be used for low-emissions fuel-lean fully-premixed, or fuel-rich fully-premixed hydrogen-air combustion, or for combustion with other gases such as methane or other hydrocarbons, or even liquid fuels.

  3. The method of waste liquid atomization/incineration by using ultrasonic industrial burners

    International Nuclear Information System (INIS)

    Bartonek, Thomas

    1999-01-01

    The problem of burning a fuel is closely related to distributing that fuel and mixing it with the combustion air within a pre-designated space, the combustion chamber. For fuel engineers, the rule of thumb is unchanged: mix it and it will burn. That is why the burner designer focuses his attention on incorporating the best possible atomization and mixing, equipment, i.c. in the end, on the construction of the atomizer nozzle and the control of the combustion air. It was these considerations plus the inability of conventional burners to meet the tough demands of today's applications that led DUMAG to undertake an intensive program of research which has now been crowned with success. Below, basic points drawn from the fundamental knowledge of all fuel engineers have been included to bring into sharper focus the operating principles of the DUMAG Ultrasonic Industrial Burner, a world class Austrian product. This paper describes a plant which has been operating without incident since October 1977. Its level of operational effectiveness is at least equivalent to that of a standard oil burner plant. The plant is also in full compliance with current environmental standards following the installation of additional safety equipment such as pre-combustion chambers, sensors to monitor pre-combustion chamber temperatures, cut-off valves for reaction water and solvents to block their flow if no heating oil is being fed in, flue gas density monitor, and finer atomization and better mixing by means of an ultrasonic system - even with fluctuations in the viscosity. By eliminating disposal costs and recovering power from liquid waste materials, the entire plant pays for itself within one year. (Original)

  4. Synthesis of Titanium Dioxide Nanoparticles Using a Double-Slit Curved Wall-Jet Burner

    KAUST Repository

    Ismail, Mohamed

    2016-05-04

    A novel double-slit curved wall-jet (DS-CWJ) burner was proposed and utilized for flame synthesis. This burner was comprised of double curved wall-jet nozzles with coaxial slits; the inner slit was for the delivery of titanium tetraisopropoxide (TTIP) precursor while the outer one was to supply premixed fuel/air mixture of ethylene (C2H4) or propane (C3H8). This configuration enabled rapid mixing between the precursor and reactants along the curved surface and inside the recirculation zone of the burner. Particle growth of titanium dioxide (TiO2) nanoparticles and their phases was investigated with varying equivalence ratio and Reynolds number. Flow field and flame structure were measured using particle image velocimetry (PIV) and OH planar laser-induced fluorescence (PLIF) techniques, respectively. The nanoparticles were characterized using high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and nitrogen adsorption Brunauer–Emmett–Teller (BET) for surface area analysis. The flow field consisted of a wall-jet region leading to a recirculation zone, an interaction jet region, followed by a merged-jet region. The DS-CWJ burner revealed appreciable mixing characteristics between the precursor and combustion gases near the nozzle regions, with a slight increase in the axial velocity due to the precursor injection. The precursor supply had a negligible effect on the flame structure. The burner produced a reasonably uniform size (13–18 nm) nanoparticles with a high BET surface area (>100 m2/g). The phase of TiO2 nanoparticles was mainly dependent on the equivalence ratio and fuel type, which impact flame height, heat release rate, and high temperature residence time of the precursor vapor. For ethylene flames, the anatase content increased with the equivalence ratio, whereas it decreased in the case of propane flames. The synthesized TiO2 nanoparticles exhibited high crystallinity and the anatase phase was dominant at high equivalence

  5. The Effects of Combustion Parameters on Pollutant Emissions in a Porous Burner

    Directory of Open Access Journals (Sweden)

    Negin Moallemi Khiavi

    2014-06-01

    Full Text Available This paper reports a two-dimensional numerical prediction of premixed methane/air combustion in inert porous media. The two dimensional Navier-stokes equations, the two separate energy equations for solid and gas and conservation equations for chemical species are solved using finite volume method based on SIMPLE algorithm. The burner under study is a rectangular one with two different regions. First region is a preheating zone (low porosity matrix that followed by the actual combustion region (high porosity matrix. For simulating the chemical reactions, skeletal mechanism (26 species and 77 reactions is used. For studying the pollutant emissions in this porous burner, the effects of porous matrix properties, excess air ratio and inlet velocity are studied. The predicted gas temperature contour and pollutant formations are in good agreement with the available experimental data. The results indicate that the downstream of the burner should be constructed from materials with high conductivity, high convective heat transfer coefficient and high porosity in order to decrease the CO and NO emissions. Also, with increasing the inlet velocity of gas mixture and the excess air ratio, the pollutant emissions are decreased.

  6. ZZ WPPR-FR-MOX/BNCMK, Benchmark on Pu Burner Fast Reactor

    International Nuclear Information System (INIS)

    Garnier, J.C.; Ikegami, T.

    1993-01-01

    Description of program or function: In order to intercompare the characteristics of the different reactors considered for Pu recycling, in terms of neutron economy, minor actinide production, uranium content versus Pu burning, the NSC Working Party on Physics of Plutonium Recycling (WPPR) is setting up several benchmark studies. They cover in particular the case of the evolution of the Pu quality and Pu fissile content for Pu recycling in PWRs; the void coefficient in PWRs partly fuelled with MOX versus Pu content; the physics characteristics of non-standard fast reactors with breeding ratios around 0.5. The following benchmarks are considered here: - Fast reactors: Pu Burner MOX fuel, Pu Burner metal fuel; - PWRs: MOX recycling (bad quality Pu), Multiple MOX recycling

  7. Evaluation of a high-temperature burner-duct-recuperator system

    Science.gov (United States)

    1990-07-01

    The U.S. Department of Energy's (DOE) Office of Industrial Technologies (OIT) sponsors research and development (R and D) to improve the energy efficiency of American industry and to provide for fuel flexibility. OIT has funded a multiyear R and D project by the Babcock and Wilcox Company (B and W) to design, fabricate, field test, and evaluate a high-temperature burner-duct-recuperator (HTBDR) system. This ceramic-based recuperator system recovers waste heat from the corrosive, high-temperature (2170 F) flue gas stream of a steel soaking pit to preheat combustion air to as high as 1700 F. The preheated air is supplied to a high-temperature burner. The B and W R and D program, which is now complete, involved several activities, including selecting and evaluating ceramic materials, designing the system, and developing and evaluating the prototype. In addition, a full-scale unit was tested at a B and W steel soaking pit. The full-scale system consisted of a modular single-stage ceramic recuperator, a conventional two-pass metallic recuperator, a high-temperature burner, fans, insulated ducting, and associated controls and instrumentation. The metallic recuperator preheated combustion air to about 750 F before it passed to the ceramic module. This technical case study describes the DOE/B and W recuperator project and highlights the field tests of the full-scale recuperator system. The document makes results of field tests and data analysis available to other researchers and private industry. It discusses project status, summarizes field tests, and reviews the potential effects the technology will have on energy use and system economics.

  8. Structure of diffusion flames from a vertical burner

    Science.gov (United States)

    Mark A. Finney; Dan Jimenez; Jack D. Cohen; Isaac C. Grenfell; Cyle Wold

    2010-01-01

    Non-steady and turbulent flames are commonly observed to produce flame contacts with adjacent fuels during fire spread in a wide range of fuel bed depths. A stationary gas-fired burner (flame wall) was developed to begin study of flame edge variability along an analagous vertical fuel source. This flame wall is surrogate for a combustion interface at the edge of a deep...

  9. Overview of the future upgrade of the INFN-LNS superconducting cyclotron

    Science.gov (United States)

    Calabretta, Luciano; Calanna, Alessandra; Cuttone, Giacomo; D'Agostino, Grazia; Rifuggiato, Danilo; Domenico Russo, Antonio

    2017-06-01

    The LNS Superconducting Cyclotron, named “Ciclotrone Superconduttore” (CS), has been in operation for more than 20 years. A wide range of ion species from hydrogen to lead, with energy in the range 10 to 80 AMeV, have been delivered to users. The maximum beam power is limited to 100 W due to the beam dissipation on the electrostatic deflectors. To fulfil the demand of users aiming at studying rare processes in nuclear physics, an upgrade of the cyclotron is necessarily intended to increase the intensity of ion beams with mass lower than 40 a.m.u. up to a power 10 kW. This will be achieved by means of extraction by stripping. This solution needs to replace the cryostat including the superconducting coils. The present capability of the cyclotron will be maintained, i.e. all the ion species allowed by the operating diagram will be available, being extracted by electrostatic extraction. In addition to the high power beams for nuclear physics, it will be possible to produce medical radioisotopes like 211At using an internal target.

  10. Curved wall-jet burner for synthesizing titania and silica nanoparticles

    KAUST Repository

    Ismail, Mohamed; Memon, Nasir; Mansour, Morkous S.; Anjum, Dalaver H.; Chung, Suk-Ho

    2015-01-01

    A novel curved wall-jet (CWJ) burner was designed for flame synthesis, by injecting precursors through a center tube and by supplying fuel/air mixtures as an annular-inward jet for rapid mixing of the precursors in the reaction zone. Titanium

  11. Effect of Low Frequency Burner Vibrations on the Characteristics of Jet Diffusion Flames

    Directory of Open Access Journals (Sweden)

    C. Kanthasamy

    2012-03-01

    Full Text Available Mechanical vibrations introduced in diffusion flame burners significantly affect the flame characteristics. In this experimental study, the effects of axial vibrations on the characteristics of laminar diffusion flames are investigated systematically. The effect of the frequency and amplitude of the vibrations on the flame height oscillations and flame stability is brought out. The amplitude of flame height oscillations is found to increase with increase in both frequency and amplitude of burner vibrations. Vibrations are shown to enhance stability of diffusion flames. Although flame lifts-off sooner with vibrations, stability of the flame increases.

  12. IR sensor for monitoring of burner flame; IR sensor foer oevervakning av braennarflamma

    Energy Technology Data Exchange (ETDEWEB)

    Svanberg, Marcus; Funkquist, Jonas; Clausen, Soennik; Wetterstroem, Jonas

    2007-12-15

    To obtain a smooth operation of the coal-fired power plants many power plant managers have installed online mass flow measurement of coal to all burners. This signal is used to monitor the coal mass flow to the individual burner and match it with appropriate amount of air and also to monitor the distribution of coal between the burners. The online mass flow measurement system is very expensive (approximately 150 kEUR for ten burners) and is not beneficial for smaller plants. The accuracy of the measurement and the sample frequency are also questionable. The idea in this project has been to evaluate a cheaper system that can present the same information and may also provide better accuracy and faster sample frequency. The infrared sensor is a cheap narrow banded light emission sensor that can be placed in a water cooed probe. The sensor was directed at the burner flame and the emitted light was monitored. Through calibration the mass flow of coal can be presented. Two measurement campaigns were performed. Both campaigns were carried out in Nordjyllandsverket in Denmark even though the second campaign was planned to be in Uppsala. Due to severe problems in the Uppsala plant the campaign was moved to Nordjyllandsverket. The pre-requisites for the test plant were that online measurement of coal flow was installed. In Nordjyllandsverket 4 out of 16 burners have the mass flow measurement installed. Risoe Laboratories has vast experiences in the IR technology and they provided the IR sensing equipment. One IR sensor was placed in the flame guard position just behind the flame directed towards the ignition zone. A second sensor was placed at the boiler wall directed towards the flame. The boiler wall position did not give any results and the location was not used during the second campaign. The flame-guard-positioned-sensor- signal was thoroughly evaluated and the results show that there is a clear correlation between the coal mass flow and the IR sensor signal. Tests were

  13. The generation of resonant turbulence for a premixed burner

    NARCIS (Netherlands)

    Verbeek, Antonie Alex; Pos, R.C.; Stoffels, Genie G.M.; Geurts, Bernardus J.; van der Meer, Theodorus H.

    2012-01-01

    Is it possible to optimize the turbulent combustion of a low swirl burner by using resonance in turbulence? To that end an active grid is constructed that consists of two perforated disks of which one is rotating, creating a system of pulsating jets, which in the end can be used as a central

  14. Ensemble Diffraction Measurements of Spray Combustion in a Novel Vitiated Coflow Turbulent Jet Flame Burner

    Science.gov (United States)

    Cabra, R.; Hamano, Y.; Chen, J. Y.; Dibble, R. W.; Acosta, F.; Holve, D.

    2000-01-01

    An experimental investigation is presented of a novel vitiated coflow spray flame burner. The vitiated coflow emulates the recirculation region of most combustors, such as gas turbines or furnaces; additionally, since the vitiated gases are coflowing, the burner allows exploration of the chemistry of recirculation without the corresponding fluid mechanics of recirculation. As such, this burner allows for chemical kinetic model development without obscurations caused by fluid mechanics. The burner consists of a central fuel jet (droplet or gaseous) surrounded by the oxygen rich combustion products of a lean premixed flame that is stabilized on a perforated, brass plate. The design presented allows for the reacting coflow to span a large range of temperatures and oxygen concentrations. Several experiments measuring the relationships between mixture stoichiometry and flame temperature are used to map out the operating ranges of the coflow burner. These include temperatures as low 300 C to stoichiometric and oxygen concentrations from 18 percent to zero. This is achieved by stabilizing hydrogen-air premixed flames on a perforated plate. Furthermore, all of the CO2 generated is from the jet combustion. Thus, a probe sample of NO(sub X) and CO2 yields uniquely an emission index, as is commonly done in gas turbine engine exhaust research. The ability to adjust the oxygen content of the coflow allows us to steadily increase the coflow temperature surrounding the jet. At some temperature, the jet ignites far downstream from the injector tube. Further increases in the coflow temperature results in autoignition occurring closer to the nozzle. Examples are given of methane jetting into a coflow that is lean, stoichiometric, and even rich. Furthermore, an air jet with a rich coflow produced a normal looking flame that is actually 'inverted' (air on the inside, surrounded by fuel). In the special case of spray injection, we demonstrate the efficacy of this novel burner with a

  15. Optimization of gas mixing system of premixed burner based on CFD analysis

    International Nuclear Information System (INIS)

    Zhang, Tian-Hu; Liu, Feng-Guo; You, Xue-Yi

    2014-01-01

    Highlights: • New multi-ejectors gas mixing system for premixed combustion burner is provided. • Two measures are proposed to improve the flow uniformity at the outlet of GMS. • Small improvement of uniformity induces significant decrease of pollutant emission. • Uniformity of velocity and fuel–gas mixing of ejector increases 234.2% and 2.9%. • Uniformity of flow rate and fuel–gas mixing of ejectors increases 1.9% and 2.2%. - Abstract: The optimization of gas mixing system (GMS) of premixed burner is presented by Computational Fluid Dynamics (CFD) and the uniformity at the outlet of GMS is proved experimentally to have strong influence on pollutant emission. To improve the uniformity at the outlet of GMS, the eleven distribution orifice plates and a diversion plate are introduced. The quantified analysis shows that the uniformity at the outlet of GMS is improved significantly. With applying the distribution orifice plates, the uniformity of velocity and fuel–gas mixing of single ejector is increased by 234.2% and 2.9%, respectively. With applying the diversion plate, the uniformity of flow rate and fuel–gas mixing of different ejectors is increased by 1.9% and 2.2%, respectively. The optimal measures and geometrical parameters provide an applicable guidance for the design of commercial premixed burner

  16. Fuel Evaporation in an Atmospheric Premixed Burner: Sensitivity Analysis and Spray Vaporization

    Directory of Open Access Journals (Sweden)

    Dávid Csemány

    2017-12-01

    Full Text Available Calculation of evaporation requires accurate thermophysical properties of the liquid. Such data are well-known for conventional fossil fuels. In contrast, e.g., thermal conductivity or dynamic viscosity of the fuel vapor are rarely available for modern liquid fuels. To overcome this problem, molecular models can be used. Currently, the measurement-based properties of n-heptane and diesel oil are compared with estimated values, using the state-of-the-art molecular models to derive the temperature-dependent material properties. Then their effect on droplet evaporation was evaluated. The critical parameters were liquid density, latent heat of vaporization, boiling temperature, and vapor thermal conductivity where the estimation affected the evaporation time notably. Besides a general sensitivity analysis, evaporation modeling in a practical burner ended up with similar results. By calculating droplet motion, the evaporation number, the evaporation-to-residence time ratio can be derived. An empirical cumulative distribution function is used for the spray of the analyzed burner to evaluate evaporation in the mixing tube. Evaporation number did not exceed 0.4, meaning a full evaporation prior to reaching the burner lip in all cases. As droplet inertia depends upon its size, the residence time has a minimum value due to the phenomenon of overshooting.

  17. Characteristics of premixed flames stabilized in an axisymmetric curved-wall jet burner with tip modification

    KAUST Repository

    Kim, Daejoong

    2009-11-10

    The stabilization characteristics of premixed flames in an axisymmetric curved-wall jet burner have been experimentally investigated. This burner utilized the Coanda effect on top of a burner tip. The initially spherical burner tip was modified to a flat tip and a concave tip in order to improve flame stabilization by providing enough space for flow recirculation above the burner tip region. The flow characteristics have been visualized using a schlieren technique. Small-scale turbulence structure has been observed mainly in the interaction jet region (located downstream of the recirculation region) for large jet velocity (Reynolds number >11,500). An appreciable amount of air entrainment was exhibited from the half-angle of the jet spread, approximately 20. The averaged planar laser-induced fluorescence images of the flames for this large velocity demonstrated that the strong signal of OH radicals, representing reaction zones, existed in the recirculation zone, while it was weak in the interaction jet region due to intermittency and local extinction by the generation of small scale turbulence. The OH radical signals strengthened again in the merged jet region (downstream of the interaction jet region). In extreme cases of Reynolds number over 19,000, a unique flame exhibiting OH radicals only in the recirculation zone was observed for the concave tip. The flame stabilization has been mapped by varying jet velocity and equivalence ratio, and the result showed that the stabilization characteristics were improved appreciably from the initial spherical tip design, especially for rich mixtures. The flow fields measured by a laser Doppler velocimetry confirmed the existence of recirculation zone and the expansion of the recirculation zones for the modified tips. The temperature profile measured by a coherent anti-Stokes Raman spectroscopy exhibited an intermittent nature, especially near the recirculation zone.

  18. The generation of resonant turbulence for a premixed burner

    NARCIS (Netherlands)

    Verbeek, Antonie Alex; Pos, R.C.; Stoffels, Genie G.M.; Geurts, Bernardus J.; van der Meer, Th.H.

    Is it possible to optimize the turbulent combustion of a low swirl burner by using resonance in turbu- lence? To that end an active grid is constructed that consists of two perforated disks of which one is rotat- ing, creating a system of pulsating jets, which in the end can be used as a central

  19. Burners. The decrease of nitrogen oxides in combustion process: the 2 nd generation GR LONOxFLAM burner; Les bruleurs, la reduction des oxydes d`azote dans la combustion: bruleur GR LONOxFLAM de 2. generation

    Energy Technology Data Exchange (ETDEWEB)

    Gauthier, J.C. [EGCI Pillard, 13 - Marseille (France)

    1997-12-31

    The Pillard company has developed, in cooperation with GDF (the French national gas utility), the GR-LONOxFLAM burner concept for reducing NOx emission levels and solid combustion products. The concept consists, for gaseous fuels, in the combination of an internal recirculation and a gas staging process; for liquid fuels, a separated flame process and air staging are combined. These concepts allow for an important reduction in NOx and non-burned residues, even with standard-size burners

  20. COST-EFFECTIVE CONTROL OF NOx WITH INTEGRATED ULTRA LOW-NOx BURNERS AND SNCR

    International Nuclear Information System (INIS)

    Hamid Farzan

    2001-01-01

    Coal-fired electric utilities are facing a serious challenge with regards to curbing their NO(sub x) emissions. At issue are the NO(sub x) contributions to the acid rain, ground level ozone, and particulate matter formation. Substantial NO(sub x) control requirements could be imposed under the proposed Ozone Transport Rule, National Ambient Air Quality Standards, and New Source Performance Standards. McDermott Technology, Inc. (MTI), Babcock and Wilcox (B and W), and Fuel Tech are teaming to provide an integrated solution for NO(sub x) control. The system will be comprised of an ultra low-NO(sub x) pulverized coal (PC) burner technology plus a urea-based, selective non-catalytic reduction (SNCR) system. This system will be capable of meeting a target emission limit of 0.15 lb NO(sub x)/10(sup 6) Btu and target ammonia (NH3) slip level targeted below 5 ppmV for commercial units. Our approach combines the best available combustion and post-combustion NO(sub x) control technologies. More specifically, B and W's DRB-4Z TM ultra low-NO(sub x) PC burner technology will be combined with Fuel Tech's NO(sub x)OUT (SNCR) and NO(sub x)OUT Cascade (SNCR/SCR hybrid) systems and jointly evaluated and optimized in a state-of-the-art test facility at MTI. Although the NO(sub x)OUT Cascade (SNCR/SCR hybrid) system will not be tested directly in this program, its potential application for situations that require greater NO(sub x) reductions will be inferred from other measurements (i.e., SNCR NO(sub x) removal efficiency plus projected NO(sub x) reduction by the catalyst based on controlled ammonia slip). Our analysis shows that the integrated ultra low-NO(sub x) burner and SNCR system has the lowest cost when the burner emissions are 0.25 lb NO(sub x)/10(sup 6) Btu or less. At burner NO(sub x) emission level of 0.20 lb NO(sub x)/10(sup 6) Btu, the levelized cost per ton of NO(sub x) removed is 52% lower than the SCR cost

  1. Regulator of Dust and Coal Burner of Power Boilers

    Directory of Open Access Journals (Sweden)

    W. Wujcik

    2004-01-01

    Full Text Available The papers considers problems concerning introduction of neutron regulator into engineering practice. The regulator makes it possible to regulate CO, N0^ and O2 values with the purpose to optimize ejections into environment. The paper contains scheme of automation control of cyclone dust and coal burner with the help of a neutron regulator.

  2. Regenerative burner systems for batch furnaces in the steel industry; Regenerativbrenner fuer Doppel-P-Strahlheizrohre in einer Feuerverzinkungslinie

    Energy Technology Data Exchange (ETDEWEB)

    Georgiew, A. [Salzgitter Flachstahl GmbH, Salzgitter (Germany); Wuenning, J.G.; Bonnet, U. [WS Waermeprozesstechnik GmbH, Renningen (Germany)

    2007-09-15

    This article will describe the application of a new self regenerative burner in a continuous galvanizing line. After a brief introduction of the process line, the self regenerative burner will be described. Very high air preheat temperatures enable considerable energy savings and flameless oxidation suppresses the formation of NO{sub x}. (orig.)

  3. Regenerative burner systems for batch furnaces in the steel industry; Regenerativbrenner fuer Doppel-P-Strahlheizrohre in einer Feuerverzinkungslinie

    Energy Technology Data Exchange (ETDEWEB)

    Georgiew, Alexander [Salzgitter Flachstahl GmbH, Salzgitter (Germany); Wuenning, Joachim G.; Bonnet, Uwe [WS Waermeprozesstechnik GmbH, Renningen (Germany)

    2009-07-01

    This article will describe the application of a new self regenerative burner in a continuous galvanizing line. After a brief introduction of the process line, the self regenerative burner will be described. Very high air preheat temperatures enable considerable energy savings and flameless oxidation suppresses the formation of NO{sub X}. (orig.)

  4. Optimization of a premixed low-swirl burner for industrial applications

    International Nuclear Information System (INIS)

    Fable, S.E.; Cheng, R.K.

    2000-01-01

    This study was motivated by recent tests results showing that a 5cm i.d. low-swirl burner (LSB) stabilizes ultra-lean premixed turbulent flames up to 600kW. A parametric study has been performed to determine the optimum ultra-lean LSB configuration, i.e. one that will achieve low NOx and flame stability, for thermal input between 15kW to 150kW. Using Laser Doppler Velocimetry (LDV), non-reacting centerline velocity and rms fluctuation profiles were measured, and were found to show self-similar behavior. This self-similarity may explain why the flame remains stationary relative to the burner exit despite a change in bulk flow velocity from 5 to 90m/s. The recess distance of the swirler affects the shape of the mean and rms velocity profiles. Lean blow-off limits were also determined for various recess distances, and an optimum exit length was found that provides stable operation for ultra-lean flames

  5. DDS-based control loops for the RF system at INFN-LNS

    International Nuclear Information System (INIS)

    Caruso, A.; Calabretta, L.; Cosentino, G.; Sparta, A.; Speziale, F.

    2005-01-01

    In the last two years a new radio-frequency source generator has been working to synthesize the driving sinusoidal signals of the RF systems at LNS. This device is based on Direct Digital Synthesis (DDS) technique. Every time you need a constant relation of phase between several RF signals, our DDS-based multiple frequencies generator produces these high frequency waveforms. The good results of this DDS synthesizer technique, make us feel confident that we can develop a new DDS control system for the various RF equipment. The AD9852/54 a commercial DDS microchip, will be the core of this new control system. The component allows, through digital ports, the manipulation of the frequency, amplitude and phase of the developed RF-carrier without any interruption to the latter. In this way we would have a complete DDS control system capable of stabilizing amplitude, phase and tuning ensuring the present stability of the analog control loops. The remaining operations, such as turning on/off and protection of the system will be performed at the same time. The prototype of this new DDS control, its technical performances and the experimental results will be presented in this paper. (author)

  6. Integration of a wood pellet burner and a Stirling engine to produce residential heat and power

    International Nuclear Information System (INIS)

    Cardozo, Evelyn; Erlich, Catharina; Malmquist, Anders; Alejo, Lucio

    2014-01-01

    The integration a Stirling engine with a pellet burner is a promising alternative to produce heat and power for residential use. In this context, this study is focused on the experimental evaluation of the integration of a 20 kW th wood pellet burner and a 1 kW e Stirling engine. The thermal power not absorbed by the engine is used to produce hot water. The evaluation highlights the effects of pellet type, combustion chamber length and cycling operation on the Stirling engine temperatures and thermal power absorbed. The results show that the position of the Stirling engine is highly relevant in order to utilize as much as possible of the radiative heat from the burner. Within this study, only a 5 cm distance change between the Stirling engine and the pellet burner could result in an increase of almost 100 °C in the hot side of the engine. However, at a larger distance, the temperature of the hot side is almost unchanged suggesting dominating convective heat transfer from the hot flue gas. Ash accumulation decreases the temperature of the hot side of the engine after some cycles of operation when a commercial pellet burner is integrated. The temperature ratio, which is the relation between the minimum and maximum temperatures of the engine, decreases when using Ø8 mm wood pellets in comparison to Ø6 mm pellets due to higher measured temperatures on the hot side of the engine. Therefore, the amount of heat supplied to the engine is increased for Ø8 mm wood pellets. The effectiveness of the engine regenerator is increased at higher pressures. The relation between temperature of the hot side end and thermal power absorbed by the Stirling engine is nearly linear between 500 °C and 660 °C. Higher pressure inside the Stirling engine has a positive effect on the thermal power output. Both the chemical and thermal losses increase somewhat when integrating a Stirling engine in comparison to a stand-alone boiler for only heat production. The overall efficiency

  7. Sensitivity of Transmutation Capability to Recycling Scenarios in KALIMER-600 TRU Burner

    International Nuclear Information System (INIS)

    Lee, Yong Kyo; Kim, Myung Hyun

    2013-01-01

    The purpose of this study is to test transmutation and design feasibility of KALIMER burner caused from many limitations in recycling options; such as low recovery factors and external feed. Design impact from many recycling options will be tested as a sensitivity to various recycling process parameters under many recycling scenarios. Through this study, possibilities when Pyro-processing is realized with SFR can be expected in the recycling scenarios. For the development of sodium-cooled fast reactor(SFR) technology, prototype KALIMER plant is now under R and D stage in Korea. For the future application of SFR for waste transmutation, KALIMER core was designed for TRU burner by KAERI. Feasibility of TRU burner cannot be evaluated exactly because overall functional parameters in pyro-processing recycling process has not been verified yet. There is great possibility to accept undesirable process functions in pyro-processing. Only TRU nuclides composition a little differs between PWR SF and CANDU SF so first scenario has no problem operating SFR. In second scenario, the radiotoxicity of waste at 99% of TRU RF have to be confirmed whether it is proper level to reposit as Low and Intermediate Level Wastes or not. And the reactor safety at high RF of RE must be inspected. Not only third scenario but also several scenarios for good measure are being calculated and will be evaluated

  8. The effectiveness of recirculating flue gasses on a gas-fuel oil boiler unit with hearth burners

    Energy Technology Data Exchange (ETDEWEB)

    Eremeev, V V; Kovalenko, A L; Kozlov, V G

    1981-01-01

    The results of investigating the effect of recirculating flue gasses on a TP-87 boiler (D = 420 tons per hour, 14 MPa, 560 C) with a hearth composition of four gas-fuel oil burners are presented. The heat-release rate of the volume of the furnace is 136 Kw per m/sup 3/; that if a cross section of the combustion chamber is 3.2 MW/m/sup 2/. The hot air temperature is 420 C. The tests were carried out during the combustion of M-100 petroleum oil which has a moisture content of 3 / 4% and a sulfur content of 2.4%. The pressure of the oil against the mechanical sprayers is 2.9-3.0 MPa at the rated load; the temperature is 125-130 C. The recirculation of the flue gasses was organized in order to expand the regulatory stress range and decrease the discharge of nitric oxides into the atmosphere. Moreover, flue gasses with a temperature of 330-370/sup 0/C were removed from a first-degree BE gas conduit, and, using two BGD-15.5 type exhaust fans, were fed into the annular channels around the burners. The calculated velocity of the gasses at the output of the burner is equal to 35 M/s; the air velocity is 64 M/s. It is shown that the TP-87 furnace--with fuel oil hearth burners and recirculation to obtain flue gasses into independent burner ducts--makes it possible to obtain a useful stress range during almost complete fuel oil combustion with minimal air exceses by maintaining the calculated temperature of the superheated vapor. Recirculating flue gasses in a duct around the burners constitutes an effective means of decreasing the discharge of nitric oxides, and of decreasing local heat stress on the screens. However, increasing the recirculation coefficient to 0.17 causes a 0.35% increase in the loss of heat with the departing gasses (the temperature of which increases by 7 C), and a 0.15% decrease in the heat flow rate for SN, which leads to an overall drop of approx. 0.5% in the efficiency coefficient of the boiler.

  9. Firing in fluid beds and burners

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, F.; Lans, R. van der; Storm Pedersen, L.; Philbert Nielsen, H.; Aslaug Hansen, L.; Lin, W.; Johnsson, J.E.; Dam-Johansen, K.

    1998-02-01

    An investigation of the effect of co-firing straw and pulverized coal was performed. Based on experiments from pilot-scale and full-scale it was concluded that a higher fraction of straw in the fuel feedstock mixture results in lower NO and SO{sub 2} emissions. The lower NO emission was mainly due to the higher volatile content of the straw, which leads to lower stoichiometry in the gas phase and in subsequent suppression of NO{sub x} formation. This conclusion is consistent with experimental and modeling results for pure coal combustion. The effect of coal quality on NO emissions has been investigated with three coals of different characteristics in three furnaces: in the Funen power station, unit 7 (FVO7), the Midtkraft Studstrup power station, unit 4 (MKS4), and the Mitsui Babcock Energy Ltd (MBEL) test-rig. The MBEL test-rig was able to reproduce qualitatively the emissions from the MKS4 plant, and quantitatively the emissions from the FVO7 plant. The better agreement between the MBEL test-rig and FVO7 is presumed to be related to the existence of a large primary zone with a relatively low stoichiometry, diminishing the influence of near burner air and fuel mixing rate on the NO emissions. An engineering model has been developed for the prediction of NO emissions and burnout from pulverized fuel combustion in swirl burners. A simplified model for reduction of N{sub 2}O in CFBC has been developed, and simulation results are in good agreement with experimental data from a 12 MW{sub th} CFB-boiler. (EG) EFP-94. 108 refs.

  10. Modeling of complex premixed burner systems by using flamelet-generated manifolds

    NARCIS (Netherlands)

    Oijen, van J.A.; Lammers, F.A.; Goey, de L.P.H.

    2001-01-01

    The numerical modeling of realistic burner systems puts a very high demand on computational recources.The computational cost of combustion simulations can be reduced by reduction techniques which simplify the chemical kinetics. In this paper the recently introduced Flamelet-Generated Manifold method

  11. Numerical investigation of premixed combustion in a porous burner with integrated heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Farzaneh, Meisam; Shafiey, Mohammad; Shams, Mehrzad [K.N. Toosi University of Technology, Department of Mechanical Engineering, Tehran (Iran, Islamic Republic of); Ebrahimi, Reza [K.N. Toosi University of Technology, Department of Aerospace Engineering, Tehran (Iran, Islamic Republic of)

    2012-07-15

    In this paper, we perform a numerical analysis of a two-dimensional axisymmetric problem arising in premixed combustion in a porous burner with integrated heat exchanger. The physical domain consists of two zones, porous and heat exchanger zones. Two dimensional Navier-Stokes equations, gas and solid energy equations, and chemical species transport equations are solved and heat release is described by a multistep kinetics mechanism. The solid matrix is modeled as a gray medium, and the finite volume method is used to solve the radiative transfer equation to calculate the local radiation source/sink in the solid phase energy equation. Special attention is given to model heat transfer between the hot gas and the heat exchanger tube. Thus, the corresponding terms are added to the energy equations of the flow and the solid matrix. Gas and solid temperature profiles and species mole fractions on the burner centerline, predicted 2D temperature fields, species concentrations and streamlines are presented. Calculated results for temperature profiles are compared to experimental data. It is shown that there is good agreement between the numerical solutions and the experimental data and it is concluded that the developed numerical program is an excellent tool to investigate combustion in porous burner. (orig.)

  12. Reduction of exposure to ultrafine particles by kitchen exhaust hoods: the effects of exhaust flow rates, particle size, and burner position.

    Science.gov (United States)

    Rim, Donghyun; Wallace, Lance; Nabinger, Steven; Persily, Andrew

    2012-08-15

    Cooking stoves, both gas and electric, are one of the strongest and most common sources of ultrafine particles (UFP) in homes. UFP have been shown to be associated with adverse health effects such as DNA damage and respiratory and cardiovascular diseases. This study investigates the effectiveness of kitchen exhaust hoods in reducing indoor levels of UFP emitted from a gas stove and oven. Measurements in an unoccupied manufactured house monitored size-resolved UFP (2 nm to 100 nm) concentrations from the gas stove and oven while varying range hood flow rate and burner position. The air change rate in the building was measured continuously based on the decay of a tracer gas (sulfur hexafluoride, SF(6)). The results show that range hood flow rate and burner position (front vs. rear) can have strong effects on the reduction of indoor levels of UFP released from the stove and oven, subsequently reducing occupant exposure to UFP. Higher range hood flow rates are generally more effective for UFP reduction, though the reduction varies with particle diameter. The influence of the range hood exhaust is larger for the back burner than for the front burner. The number-weighted particle reductions for range hood flow rates varying between 100 m(3)/h and 680 m(3)/h range from 31% to 94% for the front burner, from 54% to 98% for the back burner, and from 39% to 96% for the oven. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. The effects of chemical kinetics and wall temperature on performance of porous media burners

    Science.gov (United States)

    mohammadi, Iman; Hossainpour, Siamak

    2013-06-01

    This paper reports a two-dimensional numerical prediction of premixed methane-air combustion in inert porous media burner by using of four multi-step mechanisms: GRI-3.0 mechanism, GRI-2.11 mechanism and the skeletal and 17 Species mechanisms. The effects of these models on temperature, chemical species and pollutant emissions are studied. A two-dimensional axisymmetric model for premixed methane-air combustion in porous media burner has developed. The finite volume method has used to solve the governing equations of methane-air combustion in inert porous media burner. The results indicate that the present four models have the same accuracy in predicting temperature profiles and the difference between these profiles is not more than 2 %. In addition, the Gri-3.0 mechanism shows the best prediction of NO emission in comparison with experimental data. The 17 Species mechanism shows good agreement in prediction of temperature and pollutant emissions with GRI-3.0, GRI-2.11 and the skeletal mechanisms. Also the effects of wall temperature on the gas temperature and mass fraction of species such as NO and CH4 are studied.

  14. A Computational Fluid Dynamics Study of Turbulence, Radiation, and Combustion Models for Natural Gas Combustion Burner

    Directory of Open Access Journals (Sweden)

    Yik Siang Pang

    2018-01-01

    Full Text Available This paper presents a Computational Fluid Dynamics (CFD study of a natural gas combustion burner focusing on the effect of combustion, thermal radiation and turbulence models on the temperature and chemical species concentration fields. The combustion was modelled using the finite rate/eddy dissipation (FR/EDM and partially premixed flame models. Detailed chemistry kinetics CHEMKIN GRI-MECH 3.0 consisting of 325 reactions was employed to model the methane combustion. Discrete ordinates (DO and spherical harmonics (P1 model were employed to predict the thermal radiation. The gas absorption coefficient dependence on the wavelength is resolved by the weighted-sum-of-gray-gases model (WSGGM. Turbulence flow was simulated using Reynolds-averaged Navier-Stokes (RANS based models. The findings showed that a combination of partially premixed flame, P1 and standard k-ε (SKE gave the most accurate prediction with an average deviation of around 7.8% of combustion temperature and 15.5% for reactant composition (methane and oxygen. The results show the multi-step chemistry in the partially premixed model is more accurate than the two-step FR/EDM. Meanwhile, inclusion of thermal radiation has a minor effect on the heat transfer and species concentration. SKE turbulence model yielded better prediction compared to the realizable k-ε (RKE and renormalized k-ε (RNG. The CFD simulation presented in this work may serve as a useful tool to evaluate a performance of a natural gas combustor. Copyright © 2018 BCREC Group. All rights reserved Received: 26th July 2017; Revised: 9th October 2017; Accepted: 30th October 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018 How to Cite: Pang, Y.S., Law, W.P., Pung, K.Q., Gimbun, J. (2018. A Computational Fluid Dynamics Study of Turbulence, Radiation, and Combustion Models for Natural Gas Combustion Burner. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1: 155-169 (doi:10.9767/bcrec

  15. Comparison of In-Vessel Shielding Design Concepts between Sodium-cooled Fast Burner Reactor and the Sodium-cooled Fast Breeder Reactor

    International Nuclear Information System (INIS)

    Yun, Sunghwan; Kim, Sang Ji

    2015-01-01

    In this study, quantities of in-vessel shields were derived and compared each other based on the replaceable shield assembly concept for both of the breeder and burner SFRs. Korean Prototype Gen-IV Sodium-cooled Fast Reactor (PGSFR) like SFR was used as the reference reactor and calculation method reported in the reference was used for shielding analysis. In this paper, characteristics of in-vessel shielding design were studied for the burner SFR and breeder SFR based on the replaceable shield assembly concept. An in-vessel shield to prevent secondary sodium activation (SSA) in the intermediate heat exchangers (IHXs) is one of the most important structures for the pool type Sodium-cooled Fast Reactor (SFR). In our previous work, two in-vessel shielding design concepts were compared each other for the burner SFR. However, a number of SFRs have been designed and operated with the breeder concept, in which axial and radial blankets were loaded for fuel breeding, during the past several decades. Since axial and radial blanket plays a role of neutron shield, comparison of required in-vessel shield amount between the breeder and burner SFRs may be an interesting work for SFR designer. Due to the blanket, the breeder SFR showed better performance in axial neutron shielding. Hence, 10.1 m diameter reactor vessel satisfied the design limit of SSA at the IHXs. In case of the burner SFR, due to more significant axial fast neutron leakage, 10.6 m diameter reactor vessel was required to satisfy the design limit of SSA at the IHXs. Although more efficient axial shied such as a mixture of ZrH 2 and B 4 C can improve shielding performance of the burner SFR, additional fabrication difficulty may mitigate the advantage of improved shielding performance. Therefore, it can be concluded that the breeder SFR has better characteristic in invessel shielding design to prevent SSA at the IHXs than the burner SFR in the pool-type reactor

  16. Experience from performance testing of low NOx burners for refinery heaters; Tests de performance avec des bruleurs de raffinerie a basse emission de NOx

    Energy Technology Data Exchange (ETDEWEB)

    Boden, J.C. [Refining Technology, BP Oil International, Sunbury (United Kingdom)

    2001-07-01

    Developments in low NOx burner technology have resulted in major reductions in NOx emissions from refinery process heaters. However, the techniques used in low NOx burners to reduce NOx emissions can potentially affect other key aspects of burner performance, particularly flame stability and completeness of combustion. BP has evaluated many of the currently available low and ultra-low NOx burners, both natural and forced draught, in its purpose-built test furnace. This extensive test programme has shown that to be a reliable predictor of actual performance a test rig must recreate accurately the real furnace conditions, particularly with respect to furnace and hearth temperatures. The testing has demonstrated the NOx emissions to be expected in practice from different generic types of burner, conventional, low NOx and ultra-low NOx, and has highlighted the sets of conditions most likely to lead to combustion performance problems. (authors)

  17. Blow-off characteristics of turbulent premixed flames in curved-wall Jet Burner

    KAUST Repository

    Mansour, Morkous S.; Mannaa, O.; Chung, Suk-Ho

    2015-01-01

    and simultaneously stereoscopic particle image velocimetry (SPIV) quantified the turbulent flow field features. Ethylene/air flames were stabilized in CWJ burner to determine the sequence of events leading to blowoff. For stably burning flames far from blowoff

  18. Role of the outer-edge flame on flame extinction in nitrogen-diluted non-premixed counterflow flames with finite burner diameters

    KAUST Repository

    Chung, Yong Ho

    2013-03-01

    This study of nitrogen-diluted non-premixed counterflow flames with finite burner diameters investigates the important role of the outer-edge flame on flame extinction through experimental and numerical analyses. It explores flame stability diagrams mapping the flame extinction response of nitrogen-diluted non-premixed counterflow flames to varying global strain rates in terms of burner diameter, burner gap, and velocity ratio. A critical nitrogen mole fraction exists beyond which the flame cannot be sustained; the critical nitrogen mole fraction versus global strain rate curves have C-shapes for various burner diameters, burner gaps, and velocity ratios. At sufficiently high strain-rate flames, these curves collapse into one curve; therefore, the flames follow the one-dimensional flame response of a typical diffusion flame. Low strain-rate flames are significantly affected by radial conductive heat loss, and therefore flame length. Three flame extinction modes are identified: flame extinction through shrinkage of the outer-edge flame with or without oscillations at the outer-edge flame prior to the extinction, and flame extinction through a flame hole at the flame center. The extinction modes are significantly affected by the behavior of the outer-edge flame. Detailed explanations are provided based on the measured flame-surface temperature and numerical evaluation of the fractional contribution of each term in the energy equation. Radial conductive heat loss at the flame edge to ambience is the main mechanism of extinction through shrinkage of the outer-edge flame in low strain-rate flames. Reduction of the burner diameter can extend the flame extinction mode by shrinking the outer-edge flame in higher strain-rate flames. © 2012 Elsevier Ltd. All rights reserved.

  19. Correction of edge-flame propagation speed in a counterflow, annular slot burner

    KAUST Repository

    Tran, Vu Manh; Cha, Min

    2015-01-01

    to study the fundamental behaviors of edge-flames. In addition, our burner has easy optical access for detailed laser diagnostics. Flame displacement speeds were measured using a high-speed camera and related flow fields of unburned gases were visualized

  20. Pollutant Exposures from Natural Gas Cooking Burners: A Simulation-Based Assessment for Southern California

    Energy Technology Data Exchange (ETDEWEB)

    Logue, Jennifer M.; Klepeis, Neil E.; Lobscheid, Agnes B.; Singer, Brett C.

    2014-06-01

    Residential natural gas cooking burners (NGCBs) can emit substantial quantities of pollutants and they are typically used without venting. The objective of this study is to quantify pollutant concentrations and occupant exposures resulting from NGCB use in California homes. A mass balance model was applied to estimate time-dependent pollutant concentrations throughout homes and the "exposure concentrations" experienced by individual occupants. The model was applied to estimate nitrogen dioxide (NO{sub 2}), carbon monoxide (CO), and formaldehyde (HCHO) concentrations for one week each in summer and winter for a representative sample of Southern California homes. The model simulated pollutant emissions from NGCBs, NO{sub 2} and CO entry from outdoors, dilution throughout the home, and removal by ventilation and deposition. Residence characteristics and outdoor concentrations of CO and NO{sub 2} were obtained from available databases. Ventilation rates, occupancy patterns, and burner use were inferred from household characteristics. Proximity to the burner(s) and the benefits of using venting range hoods were also explored. Replicate model executions using independently generated sets of stochastic variable values yielded estimated pollutant concentration distributions with geometric means varying less than 10%. The simulation model estimates that in homes using NGCBs without coincident use of venting range hoods, 62%, 9%, and 53% of occupants are routinely exposed to NO{sub 2}, CO, and HCHO levels that exceed acute health-based standards and guidelines. NGCB use increased the sample median of the highest simulated 1-hr indoor concentrations by 100, 3000, and 20 ppb for NO{sub 2}, CO, and HCHO, respectively. Reducing pollutant exposures from NGCBs should be a public health priority. Simulation results suggest that regular use of even moderately effective venting range hoods would dramatically reduce the percentage of homes in which concentrations exceed health

  1. Influence of the burner swirl on the azimuthal instabilities in an annular combustor

    Science.gov (United States)

    Mazur, Marek; Nygård, Håkon; Worth, Nicholas; Dawson, James

    2017-11-01

    Improving our fundamental understanding of thermoacoustic instabilities will aid the development of new low emission gas turbine combustors. In the present investigation the effects of swirl on the self-excited azimuthal combustion instabilities in a multi-burner annular annular combustor are investigated experimentally. Each of the burners features a bluff body and a swirler to stabilize the flame. The combustor is operated with an ethylene-air premixture at powers up to 100 kW. The swirl number of the burners is varied in these tests. For each case, dynamic pressure measurements at different azimuthal positions, as well as overhead imaging of OH* of the entire combustor are conducted simultaneously and at a high sampling frequency. The measurements are then used to determine the azimuthal acoustic and heat release rate modes in the chamber and to determine whether these modes are standing, spinning or mixed. Furthermore, the phase shift between the heat release rate and pressure and the shape of these two signals are analysed at different azimuthal positions. Based on the Rayleigh criterion, these investigations allow to obtain an insight about the effects of the swirl on the instability margins of the combustor. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant agreement n° 677931 TAIAC).

  2. Design and construction of a regenerative radiant tube burner

    International Nuclear Information System (INIS)

    Henao, Diego Alberto; Cano C, Carlos Andres; Amell Arrieta, Andres A.

    2002-01-01

    The technological development of the gas industry in Colombia, aiming at efficient and safe use of the natural gas, requires the assimilation and adaptation of new generation, technologies for this purpose in this article results are presented on the design, construction and characterization of a prototype of a burner of regenerative radiant robe with a thermal power of 9,94 kW and a factor of air 1,05. This system takes advantage of the high exit temperature of the combustion smokes, after they go trough a metallic robe where they transfer the heat by radiation, to heat a ceramic channel that has the capacity to absorbing a part of the heat of the smokes and then transferring them to a current of cold air. The benefits of air heating are a saving in fuel, compared with other processes that don't incorporate the recovery of heat from the combustion gases. In this work it was possible to probe a methodology for the design of this type of burners and to reach maximum temperatures of heating of combustion air of 377,9 centigrade degrees, using a material available in the national market, whose regenerative properties should be studied in depth

  3. Measurements of non-reacting and reacting flow fields of a liquid swirl flame burner

    Science.gov (United States)

    Chong, Cheng Tung; Hochgreb, Simone

    2015-03-01

    The understanding of the liquid fuel spray and flow field characteristics inside a combustor is crucial for designing a fuel efficient and low emission device. Characterisation of the flow field of a model gas turbine liquid swirl burner is performed by using a 2-D particle imaging velocimetry(PIV) system. The flow field pattern of an axial flow burner with a fixed swirl intensity is compared under confined and unconfined conditions, i.e., with and without the combustor wall. The effect of temperature on the main swirling air flow is investigated under open and non-reacting conditions. The result shows that axial and radial velocities increase as a result of decreased flow density and increased flow volume. The flow field of the main swirling flow with liquid fuel spray injection is compared to non-spray swirling flow. Introduction of liquid fuel spray changes the swirl air flow field at the burner outlet, where the radial velocity components increase for both open and confined environment. Under reacting condition, the enclosure generates a corner recirculation zone that intensifies the strength of radial velocity. The reverse flow and corner recirculation zone assists in stabilizing the flame by preheating the reactants. The flow field data can be used as validation target for swirl combustion modelling.

  4. Evaluation of Gas Reburning and Low N0x Burners on a Wall Fired Boiler

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-07-01

    Under the U.S. Department of Energy's Clean Coal Technology Program (Round 3), a project was completed to demonstrate control of boiler NOX emissions and to a lesser degree, due to coal replacement, SO2 emissions. The project involved combining Gas Reburning with Low NOX Burners (GR-LNB) on a coal-fired electric utility boiler to determine if high levels of NO, reduction (70VO) could be achieved. Sponsors of the project included the U.S. Depatiment of Energy, the Gas Research Institute, Public Service Company of Colorado, Colorado Interstate Gas, Electric Power Research Institute, and the Energy and Environmental Research Corporation. The GR-LNB demonstration was petformed on Public Service Company of Colorado's (PSCO) Cherokee Unit #3, located in Denver, Colorado. This unit is a 172 MW~ wall-fired boiler that uses Colorado bituminous, low-sulfur coal. It had a baseline NO, emission level of 0.73 lb/1 OG Btu using conventional burners. Low NOX burners are designed to yield lower NOX emissions than conventional burners. However, the NOX control achieved with this technique is limited to 30-50Y0. Also, with LNBs, CO emissions can increase to above acceptable standards. Gas Reburning (GR) is designed to reduce NO, in the flue gas by staged fuel combustion. This technology involves the introduction of' natural gas into the hot furnace flue gas stream. When combined, GR and LNBs minimize NOX emissions and maintain acceptable levels of CO emissions. A comprehensive test program was completed, operating over a wide range of boiler conditions. Over 4,000 hours of operation were achieved, providing substantial data. Measurements were taken to quantify reductions in NOX emissions, the impact on boiler equipment and operability and factors influencing costs. The GR-LNB technology achieved good NO, emission reductions and the goals of the project were achieved. Although the performance of the low NOX burners (supplied by others) was less than expected, a NOX

  5. Utility boiler computer modeling experience in the USA for practical furnace air port and low NOx burner field design

    Energy Technology Data Exchange (ETDEWEB)

    Breen, B.P.; Urich, J.A.; Krippene, B.C. [ESA, Inc. (United States)

    2000-07-01

    This paper presents several examples of where effective furnace and low NOx burner modeling has produced substantial advantages to the low NOx combustion system designer. Using practical boiler furnace air injection port and low NOx burner maths modeling as an integral part of the design process has often made the difference between a successful low NOx combustion system field conversion project and an unsuccessful one.

  6. Modeling of pollutant formation in fully premixing surface burners using a verified practice-oriented experimental reaction-kinetic calculation method. Final report

    International Nuclear Information System (INIS)

    Ruy, C.; Kremer, H.

    1996-01-01

    The intent of the present study was to simulate quantitatively pollutant formation in premixing surface burners and to describe qualitatively the share of the premixing flame in pollut emissions from atmospheric burners. For this purpose reaction-kinetic programmes for one-dimensional premixing flames were extended by a terms describing heat discharge through gas radiation. Furthermore, the calculation range for the flame was extended far into the secondary reaction zone. Temperature, CO, and NO x profiles were measured in the secondary reaction zone of premixing burners at standard pressure. The air-fuel ratio was calculated within the practically relevant range between 0.5 and 1.5, as was load behaviour. (DG) [de

  7. Numerical study of turbulent normal diffusion flame CH4-air stabilized by coaxial burner

    Directory of Open Access Journals (Sweden)

    Riahi Zouhair

    2013-01-01

    Full Text Available The practical combustion systems such as combustion furnaces, gas turbine, engines, etc. employ non-premixed combustion due to its better flame stability, safety, and wide operating range as compared to premixed combustion. The present numerical study characterizes the turbulent flame of methane-air in a coaxial burner in order to determine the effect of airflow on the distribution of temperature, on gas consumption and on the emission of NOx. The results in this study are obtained by simulation on FLUENT code. The results demonstrate the influence of different parameters on the flame structure, temperature distribution and gas emissions, such as turbulence, fuel jet velocity, air jet velocity, equivalence ratio and mixture fraction. The lift-off height for a fixed fuel jet velocity is observed to increase monotonically with air jet velocity. Temperature and NOx emission decrease of important values with the equivalence ratio, it is maximum about the unity.

  8. A numerical study of a premixed flame on a slit burner

    NARCIS (Netherlands)

    Somers, L.M.T.; Goey, de L.P.H.

    1995-01-01

    A numerical study of a premixed methane/air flame on a 4 mm slit burner is presented. A local grid refinement technique is used to deal with large gradients and curvature of all variables encountered in the flame, keeping the number of grid points within reasonable bounds. The method used here leads

  9. Numerical investigation into premixed hydrogen combustion within two-stage porous media burner of 1 kW solid oxide fuel cell system

    Energy Technology Data Exchange (ETDEWEB)

    Yen Tzu-Hsiang; Chen Bao-Dong [Refining and Manufacturing Research Institute, CPC Corporation, Chia-Yi City 60036, Taiwan (China); Hong Wen-Tang; Tsai Yu-Ching; Wang Hung-Yu; Huang Cheng-Nan; Lee Chien-Hsiung [Institute of Nuclear Energy Research Atomic Energy Council, Taoyuan County 32546, Taiwan (China)

    2010-07-01

    Numerical simulations are performed to analyze the combustion of the anode off-gas / cathode off-gas mixture within the two-stage porous media burner of a 1 kW solid oxide fuel cell (SOFC) system. In performing the simulations, the anode gas is assumed to be hydrogen and the combustion of the gas mixture is modeled using a turbulent flow model. The validity of the numerical model is confirmed by comparing the simulation results for the flame barrier temperature and the porous media temperature with the corresponding experimental results. Simulations are then performed to investigate the effects of the hydrogen content and the burner geometry on the temperature distribution within the burner and the corresponding operational range. It is shown that the maximum flame temperature increases with an increasing hydrogen content. In addition, it is found that the burner has an operational range of 1.2--6.5 kW when assigned its default geometry settings (i.e. a length and diameter of 0.17 m and 0.06 m, respectively), but increases to 2--9 kW and 2.6--11.5 kW when the length and diameter are increased by a factor of 1.5, respectively. Finally, the operational range increases to 3.5--16.5 kW when both the diameter and the length of the burner are increased by a factor of 1.5.

  10. Behaviors of tribrachial edge flames and their interactions in a triple-port burner

    KAUST Repository

    Yamamoto, Kazuhiro; Isobe, Yusuke; Hayashi, Naoki; Yamashita, Hiroshi; Chung, Suk-Ho

    2015-01-01

    In a triple-port burner, various non-premixed flames have been observed previously. Especially for the case with two lifted flames, such configuration could be suitable in studying interaction between two tribrachial flames. In the present study

  11. Effects of bluff-body burner and coal particle size on NOx emissions and burnout

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, L.S.; Cheng, J.F.; Zeng, H.C. [Huazhong University of Science and Technology, Wuhan (China). National Coal Combustion Lab.

    1999-12-01

    Investigations on air staging have been carried out using various coals with different degrees of fineness and a variety of burners with a 92.9 kw h{sup -1} tunnel furnace burning pulverized coal. It has been observed that using the bluff-body burner can reduce both the unburned carbon in fly ash and NOx emissions in the case of air staging. The experimental results show that air-staging combustion has a more remarkable effect on NOx reduction for higher-volatile coal than for lower-volatile coal. The results also show that there is a strong influence of coal particle size on NOx emissions and unburned carbon in the fly ash in the case of air staging. 13 refs., 12 figs., 2 tabs.

  12. Beam commission of the high intensity proton source developed at INFN-LNS for the European Spallation Source

    Science.gov (United States)

    Neri, L.; Celona, L.; Gammino, S.; Miraglia, A.; Leonardi, O.; Castro, G.; Torrisi, G.; Mascali, D.; Mazzaglia, M.; Allegra, L.; Amato, A.; Calabrese, G.; Caruso, A.; Chines, F.; Gallo, G.; Longhitano, A.; Manno, G.; Marletta, S.; Maugeri, A.; Passarello, S.; Pastore, G.; Seminara, A.; Spartà, A.; Vinciguerra, S.

    2017-07-01

    At the Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS) the beam commissioning of the high intensity Proton Source for the European Spallation Source (PS-ESS) started in November 2016. Beam stability at high current intensity is one of the most important parameter for the first steps of the ongoing commissioning. Promising results were obtained since the first source start with a 6 mm diameter extraction hole. The increase of the extraction hole to 8 mm allowed improving PS-ESS performances and obtaining the values required by the ESS accelerator. In this work, extracted beam current characteristics together with Doppler shift and emittance measurements are presented, as well as the description of the next phases before the installation at ESS in Lund.

  13. Exhaust gas aftertreatment with online burner; Abgasnachbehandlung mit Online-Brenner

    Energy Technology Data Exchange (ETDEWEB)

    Rembor, Hans-Joerg; Bischler, Thomas [Huss Technologies GmbH, Nuernberg (Germany)

    2010-09-15

    In order to fulfil continuously tightened emission standards, modern Diesel engines for on and off road have to meet demands of catalytic exhaust gas aftertreatment with their thermomanagement. With an online burner from Huss Technologies, even with low load duty cycles, catalytic exhaust gas aftertreatment is possible. Diesel engine development can therefore be redirected again more on efficiency enhancement and other direct customer demands. (orig.)

  14. The effect of heat transfer on acoustics in burner stabilized flat flames

    NARCIS (Netherlands)

    Schreel, K.R.A.M.; Tillaart, van den E.L.; Janssen, R.W.M.; Goey, de L.P.H.; Koehne, H.; Lucka, K.

    2003-01-01

    Modern central heating systems use low NOx premixed burners with a largemodulation range. This can lead to noise problems which cannot be solved viatrial and error, but need accurate modelling. An acoustic analysis as part ofthe design phase can reduce the time-to-market considerably, but the

  15. Correction of edge-flame propagation speed in a counterflow, annular slot burner

    KAUST Repository

    Tran, Vu Manh

    2015-10-22

    To characterize the propagation modes of flames, flame propagation speed must be accurately calculated. The impact of propagating edge-flames on the flow fields of unburned gases is limited experimentally. Thus, few studies have evaluated true propagation speeds by subtracting the flow velocities of unburned gases from flame displacement speeds. Here, we present a counterflow, annular slot burner that provides an ideal one-dimensional strain rate and lengthwise zero flow velocity that allowed us to study the fundamental behaviors of edge-flames. In addition, our burner has easy optical access for detailed laser diagnostics. Flame displacement speeds were measured using a high-speed camera and related flow fields of unburned gases were visualized by particle image velocimetry. These techniques allowed us to identify significant modifications to the flow fields of unburned gases caused by thermal expansion of the propagating edges, which enabled us to calculate true flame propagation speeds that took into account the flow velocities of unburned gases.

  16. A high turndown, ultra low emission low swirl burner for natural gas, on-demand water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Vi H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cheng, Robert K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Therkelsen, Peter L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-06-13

    Previous research has shown that on-demand water heaters are, on average, approximately 37% more efficient than storage water heaters. However, approximately 98% of water heaters in the U.S. use storage water heaters while the remaining 2% are on-demand. A major market barrier to deployment of on-demand water heaters is their high retail cost, which is due in part to their reliance on multi-stage burner banks that require complex electronic controls. This project aims to research and develop a cost-effective, efficient, ultra-low emission burner for next generation natural gas on-demand water heaters in residential and commercial buildings. To meet these requirements, researchers at the Lawrence Berkeley National Laboratory (LBNL) are adapting and testing the low-swirl burner (LSB) technology for commercially available on-demand water heaters. In this report, a low-swirl burner is researched, developed, and evaluated to meet targeted on-demand water heater performance metrics. Performance metrics for a new LSB design are identified by characterizing performance of current on-demand water heaters using published literature and technical specifications, and through experimental evaluations that measure fuel consumption and emissions output over a range of operating conditions. Next, target metrics and design criteria for the LSB are used to create six 3D printed prototypes for preliminary investigations. Prototype designs that proved the most promising were fabricated out of metal and tested further to evaluate the LSB’s full performance potential. After conducting a full performance evaluation on two designs, we found that one LSB design is capable of meeting or exceeding almost all the target performance metrics for on-demand water heaters. Specifically, this LSB demonstrated flame stability when operating from 4.07 kBTU/hr up to 204 kBTU/hr (50:1 turndown), compliance with SCAQMD Rule 1146.2 (14 ng/J or 20 ppm NOX @ 3% O2), and lower CO emissions than state

  17. Impact of Subgrid Scale Models and Heat Loss on Large Eddy Simulations of a Premixed Jet Burner Using Flamelet-Generated Manifolds

    Science.gov (United States)

    Hernandez Perez, Francisco E.; Im, Hong G.; Lee, Bok Jik; Fancello, Alessio; Donini, Andrea; van Oijen, Jeroen A.; de Goey, L. Philip H.

    2017-11-01

    Large eddy simulations (LES) of a turbulent premixed jet flame in a confined chamber are performed employing the flamelet-generated manifold (FGM) method for tabulation of chemical kinetics and thermochemical properties, as well as the OpenFOAM framework for computational fluid dynamics. The burner has been experimentally studied by Lammel et al. (2011) and features an off-center nozzle, feeding a preheated lean methane-air mixture with an equivalence ratio of 0.71 and mean velocity of 90 m/s, at 573 K and atmospheric pressure. Conductive heat loss is accounted for in the FGM tabulation via burner-stabilized flamelets and the subgrid-scale (SGS) turbulence-chemistry interaction is modeled via presumed filtered density functions. The impact of heat loss inclusion as well as SGS modeling for both the SGS stresses and SGS variance of progress variable on the numerical results is investigated. Comparisons of the LES results against measurements show a significant improvement in the prediction of temperature when heat losses are incorporated into FGM. While further enhancements in the LES results are accomplished by using SGS models based on transported quantities and/or dynamically computed coefficients as compared to the Smagorinsky model, heat loss inclusion is more relevant. This research was sponsored by King Abdullah University of Science and Technology (KAUST) and made use of computational resources at KAUST Supercomputing Laboratory.

  18. The effect of heat transfer on acoustics in burner stabilized flat flames

    NARCIS (Netherlands)

    Schreel, K.R.A.M.; Tillaart, van den E.L.; Janssen, R.W.M.; Goey, de L.P.H.; Vovelle, C.; Lucka, K.

    2003-01-01

    Modern central heating systems use low NO$_x$ premixed burners with a large modulation range. This can lead to noise problems which cannot be solved via trial and error, but need accurate modelling. An acoustic analysis as part of the design phase can reduce the time-to-market considerably, but the

  19. Modeling of confined and unconfined laminar premixed flames on slit and tube burners

    NARCIS (Netherlands)

    Mallens, R.M.M.; Lange, de H.C.; Ven, van de C.J.H.; Goey, de L.P.H.

    1995-01-01

    A model is presented for laminar premixed Bunsen flames on slit and cylindrical burners burning in a surrounding atmosphere. A comparison between modeling and experimental results shows that the model can reproduce the experimental results within 10% accuracy. The influence of a surrounding

  20. Emissions of Jatropha oil-derived biodiesel blend fuels during combustion in a swirl burner

    Science.gov (United States)

    Norwazan, A. R.; Mohd. Jaafar, M. N.; Sapee, S.; Farouk, Hazir

    2018-03-01

    Experimental works on combustion of jatropha oil biodiesel blends of fuel with high swirling flow in swirl burner have been studied in various blends percentage. Jatropha oil biodiesel was produced using a two-step of esterification-transesterification process. The paper focuses on the emissions of biodiesel blends fuel using jatropha oil in lean through to rich air/fuel mixture combustion in swirl burner. The emissions performances were evaluated by using axial swirler amongst jatropha oil blends fuel including diesel fuel as baseline. The results show that the B25 has good emissions even though it has a higher emission of NOx than diesel fuel, while it emits as low as 42% of CO, 33% of SO2 and 50% of UHC emissions with high swirl number. These are due to the higher oxygen content in jatropha oil biodiesel.

  1. Experimental and numerical investigation of the acoustic response of multi-slit Bunsen burners

    NARCIS (Netherlands)

    Kornilov, V.N.; Rook, R.; Thije Boonkkamp, ten J.H.M.; Goey, de L.P.H.

    2009-01-01

    Experimental and numerical techniques to characterize the response of premixed methane-air flames to acoustic waves are discussed and applied to a multi-slit Bunsen burner. The steady flame shape, flame front kinematics and flow field of acoustically exited flames, as well as the flame transfer

  2. Optical diagnostics to adjust burners. Een optische diagnostiek voor het instellen van branders

    Energy Technology Data Exchange (ETDEWEB)

    Braam, A L.H.; Hulshof, H J.M.; De Jongh, W [NV KEMA, Arnhem (Netherlands)

    1991-05-01

    The most efficient method to reduce nitrogen oxides in a natural gas flame or a coal flame is a correct adjustment of the burners. A newly developed optical method to measure the temperature distribution in the flame is discussed. KEMA (a Dutch Electrotechnical Equipment Testing Agency) developed the measuring method to control the combustion process in each burner of a natural gas- or coal-fired power plant for NOx formation for a constant energy production, and for the stability of the combustion. By means of data from the temperature distribution measurements some important parameters concerning NOx formation can be determined. Attention is paid to several active and passive spectroscopic methods to measure temperatures in flames. Passive spectroscopy is considered to be the best measuring method. Concentrations of radicals (CH, CN, NH) and temperature distribution are determined by means of a spectroheliograph and a camera, flame temperatures are measured by means of metal tracers. Experimental measurements carried out in the Flevo plant (EPON) are discussed. 8 figs.

  3. Effect of the superposition of a dielectric barrier discharge onto a premixed gas burner flame

    Science.gov (United States)

    Zaima, Kazunori; Takada, Noriharu; Sasaki, Koichi

    2011-10-01

    We are investigating combustion control with the help of nonequilibrium plasma. In this work, we examined the effect of dielectric barrier discharge (DBD) on a premixed burner flame with CH4/O2/Ar gas mixture. The premixed burner flame was covered with a quartz tube. A copper electrode was attached on the outside of the quartz tube, and it was connected to a high-voltage power supply. DBD inside the quartz tube was obtained between the copper electrode and the grounded nozzle of the burner which was placed at the bottom of the quartz tube. We clearly observed that the flame length was shortened by superposing DBD onto the bottom part of the flame. The shortened flame length indicates the enhancement of the burning velocity. We measured the optical emission spectra from the bottom region of the flame. As a result, we observed clear line emissions from Ar, which were never observed from the flame without DBD. We evaluated the rotational temperatures of OH and CH radicals by spectral fitting. As a result, the rotational temperature of CH was not changed, and the rotational temperature of OH was decreased by the superposition of DBD. According to these results, it is considered that the enhancement of the burning velocity is not caused by gas heating. New reaction pathways are suggested.

  4. Crossover trial to test the acceptability of a locally produced lipid-based nutrient supplement (LNS) for children under 2 years in Cambodia: a study protocol.

    Science.gov (United States)

    Borg, Bindi; Mihrshahi, Seema; Griffin, Mark; Chamnan, Chhoun; Laillou, Arnaud; Wieringa, Frank T

    2017-09-06

    The acceptability and efficacy of existing ready-to-use supplementary and therapeutic foods has been low in Cambodia, thus limiting success in preventing and treating malnutrition among Cambodian children. In that context, UNICEF and IRD have developed a locally produced, multiple micronutrient fortified lipid-based nutrient supplement. This food is innovative, in that it uses fish instead of milk as the animal source food. Very few supplementary foods have non-milk animal source foods, and in addition they have not been widely tested. This trial will assess the novel food's acceptability to children and caregivers. This is a cluster-randomised, incomplete block, 4×4 crossover design with no blinding. It will take place in four sites in a community setting in periurban Phnom Penh. Healthy children aged 9-23 months (n=100) will eat each of four foods for 3 days at a time. The amount they consume will be measured, and at the end of each 3-day set, caregivers will assess how well their child liked the food. After 12 days, caregivers themselves will do a sensory test of the 4 foods and will rank them in terms of preference. Ethical clearance was received from the University of Queensland Medical Research Ethics Committee (2014001070) and from Cambodia's National Ethics Committee for Health Research (03/8 NECHR). ClinicalTrials.gov, identifier: LNS-CAMB-INFANTS; NCT02257437. Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. Advanced burner test reactor preconceptual design report.

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Y. I.; Finck, P. J.; Grandy, C.; Cahalan, J.; Deitrich, L.; Dunn, F.; Fallin, D.; Farmer, M.; Fanning, T.; Kim, T.; Krajtl, L.; Lomperski, S.; Moisseytsev, A.; Momozaki, Y.; Sienicki, J.; Park, Y.; Tang, Y.; Reed, C.; Tzanos, C; Wiedmeyer, S.; Yang, W.; Chikazawa, Y.; JAEA

    2008-12-16

    The goals of the Global Nuclear Energy Partnership (GNEP) are to expand the use of nuclear energy to meet increasing global energy demand, to address nuclear waste management concerns and to promote non-proliferation. Implementation of the GNEP requires development and demonstration of three major technologies: (1) Light water reactor (LWR) spent fuel separations technologies that will recover transuranics to be recycled for fuel but not separate plutonium from other transuranics, thereby providing proliferation-resistance; (2) Advanced Burner Reactors (ABRs) based on a fast spectrum that transmute the recycled transuranics to produce energy while also reducing the long term radiotoxicity and decay heat loading in the repository; and (3) Fast reactor fuel recycling technologies to recover and refabricate the transuranics for repeated recycling in the fast reactor system. The primary mission of the ABR Program is to demonstrate the transmutation of transuranics recovered from the LWR spent fuel, and hence the benefits of the fuel cycle closure to nuclear waste management. The transmutation, or burning of the transuranics is accomplished by fissioning and this is most effectively done in a fast spectrum. In the thermal spectrum of commercial LWRs, some transuranics capture neutrons and become even heavier transuranics rather than being fissioned. Even with repeated recycling, only about 30% can be transmuted, which is an intrinsic limitation of all thermal spectrum reactors. Only in a fast spectrum can all transuranics be effectively fissioned to eliminate their long-term radiotoxicity and decay heat. The Advanced Burner Test Reactor (ABTR) is the first step in demonstrating the transmutation technologies. It directly supports development of a prototype full-scale Advanced Burner Reactor, which would be followed by commercial deployment of ABRs. The primary objectives of the ABTR are: (1) To demonstrate reactor-based transmutation of transuranics as part of an

  6. AGA answers complaints on burner tip prices

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper reports that the American Gas Association has rebutted complaints that natural gas prices have dropped at the wellhead but not at the burner tip. AGA Pres. Mike Baly the an association study of the issue found that all classes of customers paid less for gas in 1991 than they did in 1984, when gas prices were at their peak. He the, the study also shows that 100% of the wellhead price decline has been passed through to natural gas consumers in the form of lower retail prices. Baly the the average cost of gas delivered to all customers classes fell by $1.12/Mcf from 1984 to 1991, which exceeds the $1.10/Mcf decline in average wellhead prices during the same period

  7. Use of numerical modeling in design for co-firing biomass in wall-fired burners

    DEFF Research Database (Denmark)

    Yin, Chungen; Rosendahl, Lasse Aistrup; Kær, Søren Knudsen

    2004-01-01

    modification to the motion and reaction due to their non-sphericity. The simulation results show a big difference between the two cases and indicate it is very significant to take into account the non-sphericity of biomass particles in order to model biomass combustion more accurately. Methods to improve...... of numerical modeling. The models currently used to predict solid fuel combustion rely on a spherical particle shape assumption, which may deviate a lot from reality for big biomass particles. A sphere gives a minimum in terms of the surface-area-to-volume ratio, which impacts significantly both motion...... and reaction of a particle. To better understand biomass combustion and thus improve the design for co-firing biomass in wall-fired burners, non-sphericity of biomass particles is considered. To ease comparison, two cases are numerically studied in a 10m long gas/biomass co-fired burner model. (1) The biomass...

  8. Increased Coal Replacement in a Cement Kiln Burner by Feeding a Mixture of Solid Hazardous Waste and Shredded Plastic Waste

    OpenAIRE

    Ariyaratne, W. K. Hiromi; Melaaen, Morten Christian; Tokheim, Lars-André

    2013-01-01

    The present study aims to find the maximum possible replacement of coal by combined feeding of plastic waste and solid hazardous waste mixed with wood chips (SHW) in rotary kiln burners used in cement kiln systems. The coal replacement should be achieved without negative impacts on product quality, emissions or overall operation of the process. A full-scale experiment was carried out in the rotary kiln burner of a cement kiln by varying SHW and plastic waste feeding rates. Experimental result...

  9. Impact of fuel quality and burner capacity on the performance of wood pellet stove

    Directory of Open Access Journals (Sweden)

    Petrović-Bećirović Sanja B.

    2015-01-01

    Full Text Available Pellet stoves may play an important role in Serbia in the future when fossil fuel fired conventional heating appliances are replaced by more efficient and environmentally friendly devices. Experimental investigation was conducted in order to examine the influence of wood pellet quality, as well as burner capacity (6, 8 and 10 kW, used in the same stove configuration, on the performance of pellet stove with declared nameplate capacity of 8 kW. The results obtained showed that in case of nominal load and combustion of pellets recommended by the stove manufacturer, stove efficiency of 80.03% was achieved. The use of lower quality pellet caused additional 1.13 kW reduction in heat output in case of nominal load and 0.63 kW in case of reduced load. This was attributed to less favourable properties and lower bulk and particle density of lower quality pellet. The use of different burner capacity has shown to have little effect on heat output and efficiency of the stove when pre-set values in the control system of the stove were not altered. It is concluded that replacement of the burner only is not sufficient to increase/decrease the declared capacity of the same stove configuration, meaning that additional measures are necessary. These measures include a new set up of the stove control system, which needs to be properly adjusted for each alteration in stove configuration. Without the adjustment mentioned, declared capacity of the stove cannot be altered, while its CO emission shall be considerably increased.

  10. Influence of the technique for injection of flue gas and the configuration of the swirl burner throat on combustion of gaseous fuel and formation of nitrogen oxides in the flame

    Science.gov (United States)

    Dvoinishnikov, V. A.; Khokhlov, D. A.; Knyaz'kov, V. P.; Ershov, A. Yu.

    2017-05-01

    How the points at which the flue gas was injected into the swirl burner and the design of the burner outlet influence the formation and development of the flame in the submerged space, as well as the formation of nitrogen oxides in the combustion products, have been studied. The object under numerical investigation is the flame of the GMVI combined (oil/gas) burner swirl burner fitted with a convergent, biconical, cylindrical, or divergent throat at the burner outlet with individual supply of the air and injection of the gaseous fuel through tubing. The burners of two designs were investigated; they differ by the absence or presence of an inlet for individual injection of the flue gas. A technique for numerical simulation of the flame based on the CFD methods widely used in research of this kind underlies the study. Based on the summarized results of the numerical simulation of the processes that occur in jet flows, the specific features of the aerodynamic pattern of the flame have been established. It is shown that the flame can be conventionally divided into several sections over its length in all investigations. The lengths of each of the sections, as well as the form of the fields of axial velocity, temperatures, concentrations of the fuel, oxygen, and carbon and nitrogen oxides, are different and determined by the design features of the burner, the flow rates of the agent, and the compositions of the latter in the burner ducts as well as the configuration of the burner throat and the temperature of the environment. To what degree the burner throat configuration and the techniques for injection of the flue gas at different ambient temperatures influence the formation of nitrogen oxides has been established. It is shown that the supply of the recirculation of flue gas into the fuel injection zone enables a considerable reduction in the formation of nitrogen oxides in the flame combustion products. It has been established that the locations of the zones of

  11. Pollutant Concentrations and Emission Rates from Scripted Natural Gas Cooking Burner Use in Nine Northern California Homes

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Delp, William W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lorenzetti, David M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Maddalena, Randy L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-10-01

    METHODS: Combustion pollutant concentrations were measured during the scripted operation of natural gas cooking burners in nine homes. In addition to a base condition of closed windows, no forced air unit (FAU) use, and no mechanical exhaust, additional experiments were conducted while operating an FAU and/or vented range hood. Test homes included a 26m2 two-room apartment, a 134m2 first floor flat, and seven detached homes of 117–226m2. There were four single-story, four two-story and one 1.5 story homes. Cooktop use entailed boiling and simmering activities, using water as a heat sink. Oven and broiler use also were simulated. Time-resolved concentrations of carbon dioxide (CO2), nitric oxide (NO), nitrogen oxides (NOX), nitrogen dioxide (NO2), particles with diameters of 6 nm or larger (PN), carbon monoxide (CO), and fine particulate matter (PM2.5) were measured in the kitchen (K) and bedroom area (BR) of each home. CO2, NO, NO2, and PN data from sequential experiments were analyzed to quantify the contribution of burner use to the highest 1h and 4h time-integrated concentrations in each room. RESULTS: Four of the nine homes had kitchen 1h NO2 exceed the national ambient air quality standard (100 ppb). Two other homes had 1h NO2 exceed 50 ppb in the kitchen, and three had 1h NO2 above 50 ppb in the bedroom, suggesting substantial exposures to anyone at home when burners are used for a single substantial event. In all homes, the highest 1h kitchen PN exceeded 2 x105 cm-3-h, and the highest 4h PN exceeded 3 x105 cm-3-hr in all homes. The lowest 1h kitchen/bedroom ratios were 1.3–2.1 for NO in the apartment and two open floor plan homes. The largest K/BR ratios of 1h NO2 were in a two-story 1990s home retrofitted for deep energy savings: ratios in this home were 3.3 to 6.6. Kitchen 1h ratios of NO, NO2 and PN to CO2 were used to calculate fuel normalized emission factors (ng J-1). Range hood use substantially reduced cooking burner pollutant concentrations both

  12. DEVELOPMENT OF A NOVEL RADIATIVELY/CONDUCTIVELY STABILIZED BURNER FOR SIGNIFICANT REDUCTION OF NOx EMISSIONS AND FOR ADVANCING THE MODELING AND UNDERSTANDING OF PULVERIZED COAL COMBUSTION AND EMISSIONS

    Energy Technology Data Exchange (ETDEWEB)

    Noam Lior; Stuart W. Churchill

    2003-10-01

    The primary objective of the proposed study was the study and analysis of, and design recommendations for, a novel radiatively-conductively stabilized combustion (RCSC) process for pulverized coal, which, based on our prior studies with both fluid fuels and pulverized coal, holds a high promise to reduce NO{sub x} production significantly. We have primarily engaged in continuing and improving our process modeling and analysis, obtained a large amount of quantitative information about the effects of the major parameters on NO{sub x} production, conducted an extensive exergy analysis of the process, evaluated the practicalities of employing the Radiatively-Conductively Stabilized Combustor (RCSC) to large power and heat plants, and improved the experimental facility. Prior experimental work has proven the feasibility of the combustor, but slagging during coal combustion was observed and should be dealt with. The primary outcomes and conclusions from the study are: (1) we developed a model and computer program that represents the pulverized coal combustion in the RCSC, (2) the model predicts that NO{sub x} emissions can be reduced by a number of methods, detailed in the report. (3) the exergy analysis points out at least a couple of possible ways to improve the exergetic efficiency in this combustor: increasing the effectiveness of thermal feedback, and adjusting the combustor mixture exit location, (4) because of the low coal flow rates necessitated in this study to obtain complete combustion in the burner, the size of a burner operating under the considered conditions would have to be up to an order of magnitude, larger than comparable commercial burners, but different flow configurations of the RCSC can yield higher feed rates and smaller dimensions, and should be investigated. Related to this contract, eleven papers were published in journals and conference proceedings, and ten invited presentations were given at university and research institutions, as well as at

  13. A comparative neutronic analysis of 150MWe TRU burner according to the coolant alteration

    International Nuclear Information System (INIS)

    Yoo, J. W.; Kim, S. J.; Kim, Y. I.

    2000-01-01

    A comparative neutronic analysis has been conducted for the small TRU burner according to their coolant material. The use of Pb-Bi coolant gave a low burnup reactivity swing and negative or less positive coolant void coefficient with harder neutron spectrum. By a lower burnup reactivity swing and higher conversion ratio of Pb-Bi cooled core, the total amount of TRU consumption was found to be small compared with Na cooled core despite of the higher MA consumption ratio of Pb-Bi cooled core. However, Pb-Bi cooled reactor have a lager margin in the coolant void coefficient, so that a variable MA composition can be loaded in the core. Accordingly, even though the Pb-Bi cooled TRU burner has not effectiveness on TRU burning in the same geometry and material condition, a flexible MA loading is envisaged to result in 10 times larger MA burning amount, still preserving a low coolant void worth

  14. Low Emissions Burner Technology for Metal Processing Industry using Byproducts and Biomass Derived Liquid Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Ajay; Taylor, Robert

    2013-09-30

    This research and development efforts produced low-emission burner technology capable of operating on natural gas as well as crude glycerin and/or fatty acids generated in biodiesel plants. The research was conducted in three stages (1) Concept definition leading to the design and development of a small laboratory scale burner, (2) Scale-up to prototype burner design and development, and (3) Technology demonstration with field vefiication. The burner design relies upon the Flow Blurring (FB) fuel injection based on aerodynamically creating two-phase flow near the injector exit. The fuel tube and discharge orifice both of inside diameter D are separated by gap H. For H < 0.25D, the atomizing air bubbles into liquid fuel to create a two-phase flow near the tip of the fuel tube. Pressurized two-phase fuel-air mixture exits through the discharge orifice, which results in expansion and breakup of air bubbles yielding a spray with fine droplets. First, low-emission combustion of diesel, biodiesel and straight VO (soybean oil) was achieved by utilizing FB injector to yield fine sprays for these fuels with significantly different physical properties. Visual images for these baseline experiments conducted with heat release rate (HRR) of about 8 kW illustrate clean blue flames indicating premixed combustion for all three fuels. Radial profiles of the product gas temperature at the combustor exit overlap each other signifying that the combustion efficiency is independent of the fuel. At the combustor exit, the NOx emissions are within the measurement uncertainties, while CO emissions are slightly higher for straight VO as compared to diesel and biodiesel. Considering the large variations in physical and chemical properties of fuels considered, the small differences observed in CO and NOx emissions show promise for fuel-flexible, clean combustion systems. FB injector has proven to be very effective in atomizing fuels with very different physical properties, and it offers a

  15. Fuel rich and fuel lean catalytic combustion of the stabilized confined turbulent gaseous diffusion flames over noble metal disc burners

    Directory of Open Access Journals (Sweden)

    Amal S. Zakhary

    2014-03-01

    Full Text Available Catalytic combustion of stabilized confined turbulent gaseous diffusion flames using Pt/Al2O3 and Pd/Al2O3 disc burners situated in the combustion domain under both fuel-rich and fuel-lean conditions was experimentally studied. Commercial LPG fuel having an average composition of: 23% propane, 76% butane, and 1% pentane was used. The thermal structure of these catalytic flames developed over Pt/Al2O3 and Pd/Al2O3 burners were examined via measuring the mean temperature distribution in the radial direction at different axial locations along the flames. Under-fuel-rich condition the flames operated over Pt catalytic disc attained high temperature values in order to express the progress of combustion and were found to achieve higher activity as compared to the flames developed over Pd catalytic disc. These two types of catalytic flames demonstrated an increase in the reaction rate with the downstream axial distance and hence, an increase in the flame temperatures was associated with partial oxidation towards CO due to the lack of oxygen. However, under fuel-lean conditions the catalytic flame over Pd catalyst recorded comparatively higher temperatures within the flame core in the near region of the main reaction zone than over Pt disc burner. These two catalytic flames over Pt and Pd disc burners showed complete oxidation to CO2 since the catalytic surface is covered by more rich oxygen under the fuel-lean condition.

  16. Effect of energetic electrons on combustion of premixed burner flame

    Science.gov (United States)

    Sasaki, Koichi

    2011-10-01

    In many studies of plasma-assisted combustion, authors superpose discharges onto flames to control combustion reactions. This work is motivated by more fundamental point of view. The standpoint of this work is that flames themselves are already plasmas. We irradiated microwave power onto premixed burner flame with the intention of heating electrons in it. The microwave power was limited below the threshold for a discharge. We obtained the enhancement of burning velocity by the irradiation of the microwave power, which was understood by the shortening of the flame length. At the same time, we observed the increases in the optical emission intensities of OH and CH radicals. Despite the increases in the optical emission intensities, the optical emission spectra of OH and CH were not affected by the microwave irradiation, indicating that the enhancement of the burning velocity was not attributed to the increase in the gas temperature. On the other hand, we observed significant increase in the optical emission intensity of the second positive system of molecular nitrogen, which is a clear evidence for electron heating in the premixed burner flame. Therefore, it is considered that the enhancement of the burning velocity is obtained by nonequilibrium combustion chemistry which is driven by energetic electrons. By irradiating pulsed microwave power, we examined the time constants for the increases and decreases in the optical emission intensities of N2, OH, CH, and continuum radiation.

  17. Transfer function calculations of segregated elements in a simplified slit burner with heat exchanger

    NARCIS (Netherlands)

    Hosseini, N.; Kornilov, V.N.; Teerling, O. J.; Lopez Arteaga, I.; de Goey, Ph.

    A simplified burner-heat exchanger system is numerically modeled in order to investigate the effects of different elements on the response of the whole system to velocity excitation. We model the system in a 2D CFD code, considering a linear array of multiple Bunsen-type flames with heat exchanger

  18. Time evolution of propagating nonpremixed flames in a counterflow, annular slot burner under AC electric fields

    KAUST Repository

    Tran, Vu Manh; Cha, Min

    2016-01-01

    alternating current electric fields to a gap between the upper and lower parts of a counterflow, annular slot burner and present the characteristics of the propagating nonpremixed edge-flames produced. Contrary to many other previous studies, flame

  19. Premixed burner experiments: Geometry, mixing, and flame structure issues

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, A.K.; Lewis, M.J.; Gupta, M. [Univ of Maryland, College Park, MD (United States)] [and others

    1995-10-01

    This research program is exploring techniques for improved fuel-air mixing, with the aim of achieving combustor operations up to stoichiometric conditions with minimal NO x and maximum efficiency. The experimental studies involve the use of a double-concentric natural gas burner that is operable in either premixed or non-premixed modes, and the system allows systematic variation of equivalence ratio, swirl strength shear length region and flow momentum in each annulus. Flame structures formed with various combinations of swirl strengths, flow throughput and equivalence ratios in premixed mode show the significant impact of swirl flow distribution on flame structure emanating from the mixedness. This impact on flame structure is expected to have a pronounced effect on the heat release rate and the emission of NO{sub x}. Thus, swirler design and configuration remains a key factor in the quest for completely optimized combustion. Parallel numerical studies of the flow and combustion phenomena were carried out, using the RSM and thek-{epsilon} turbulence models. These results have not only indicated the strengths and limitations of CFD in performance and pollutants emission predictions, but have provided guidelines on the size and strength of the recirculation produced and the spatio-temporal structure of the combustion flowfield. The first stage of parametric studies on geometry and operational parameters at Morgan State University have culminated in the completion of a one-dimensional flow code that is integrated with a solid, virtual model of the existing premixed burner. This coupling will provide the unique opportunity to study the impact of geometry on the flowfield and vice-versa, with particular emphasis on concurrent design optimization.

  20. Linear accelerator for burner-reactor

    International Nuclear Information System (INIS)

    Batskikh, G.I.; Murin, B.P.; Fedotov, A.P.

    1991-01-01

    Future development of nuclear power engineering depends on the successful solution of two key problems of safety and utilization of high level radioactive wastes (HLRW) of atomic power plants (APP). Modern methods of HLRW treatment involve solidification, preliminary storing for a period of 30-50 years necessary for the decay of long-living nuclides and final burial in geological formations several hundred meters below the ground surface. The depth burial of the radioactive wastes requires complicated under ground constructions. It's very expensive and doesn't meet modern ecological requirements. Alternative modern and more reasonable methods of APP HLRW treatment are under consideration now. One of the methods involves separation of APP waste radionuclides for use in economy with subsequent transmutation of the long-living isotopes into the short-living ones by high-intensity neutron fluxes generated by proton accelerators. The installation intended for the long-living radionuclides transmutation into the short-living ones is called burner-reactor. It can be based on the continuous regime proton accelerator with 1.5 GeV energy, 0.3 A current and beam mean power of 450 MW. The preferable type of the proton accelerator with the aforementioned parameters is the linear accelerator

  1. Enhanced Combustion Low NOx Pulverized Coal Burner

    Energy Technology Data Exchange (ETDEWEB)

    David Towle; Richard Donais; Todd Hellewell; Robert Lewis; Robert Schrecengost

    2007-06-30

    For more than two decades, Alstom Power Inc. (Alstom) has developed a range of low cost, infurnace technologies for NOx emissions control for the domestic U.S. pulverized coal fired boiler market. This includes Alstom's internally developed TFS 2000{trademark} firing system, and various enhancements to it developed in concert with the U.S. Department of Energy. As of the date of this report, more than 270 units representing approximately 80,000 MWe of domestic coal fired capacity have been retrofit with Alstom low NOx technology. Best of class emissions range from 0.18 lb/MMBtu for bituminous coal to 0.10 lb/MMBtu for subbituminous coal, with typical levels at 0.24 lb/MMBtu and 0.13 lb/MMBtu, respectively. Despite these gains, NOx emissions limits in the U.S. continue to ratchet down for new and existing boiler equipment. On March 10, 2005, the Environmental Protection Agency (EPA) announced the Clean Air Interstate Rule (CAIR). CAIR requires 25 Eastern states to reduce NOx emissions from the power generation sector by 1.7 million tons in 2009 and 2.0 million tons by 2015. Low cost solutions to meet such regulations, and in particular those that can avoid the need for a costly selective catalytic reduction system (SCR), provide a strong incentive to continue to improve low NOx firing system technology to meet current and anticipated NOx control regulations. The overall objective of the work is to develop an enhanced combustion, low NOx pulverized coal burner, which, when integrated with Alstom's state-of-the-art, globally air staged low NOx firing systems will provide a means to achieve: Less than 0.15 lb/MMBtu NOx emissions when firing a high volatile Eastern or Western bituminous coal, Less than 0.10 lb/MMBtu NOx emissions when firing a subbituminous coal, NOx reduction costs at least 25% lower than the costs of an SCR, Validation of the NOx control technology developed through large (15 MWt) pilot scale demonstration, and Documentation required for

  2. Flame Motion In Gas Turbine Burner From Averages Of Single-Pulse Flame Fronts

    Energy Technology Data Exchange (ETDEWEB)

    Tylli, N.; Hubschmid, W.; Inauen, A.; Bombach, R.; Schenker, S.; Guethe, F. [Alstom (Switzerland); Haffner, K. [Alstom (Switzerland)

    2005-03-01

    Thermo acoustic instabilities of a gas turbine burner were investigated by flame front localization from measured OH laser-induced fluorescence single pulse signals. The average position of the flame was obtained from the superposition of the single pulse flame fronts at constant phase of the dominant acoustic oscillation. One observes that the flame position varies periodically with the phase angle of the dominant acoustic oscillation. (author)

  3. Central recirculation zone analysis in an unconfined tangential swirl burner with varying degrees of premixing

    Energy Technology Data Exchange (ETDEWEB)

    Valera-Medina, A. [CIATEQ, Parque Industrial Bernardo Quintana, Turbomachinery Department, Queretaro (Mexico); Syred, N.; Kay, P.; Griffiths, A. [Cardiff University, School of Engineering, Cardiff, Wales (United Kingdom)

    2011-06-15

    Swirl-stabilised combustion is one of the most widely used techniques for flame stabilisation, uses ranging from gas turbine combustors to pulverised coal-fired power stations. In gas turbines, lean premixed systems are of especial importance, giving the ability to produce low NOx systems coupled with wide stability limits. The common element is the swirl burner, which depends on the generation of an aerodynamically formed central recirculation zone (CRZ) and which serves to recycle heat and active chemical species to the root of the flame as well as providing low-velocity regions where the flame speed can match the local flow velocity. Enhanced mixing in and around the CRZ is another beneficial feature. The structure of the CRZ and hence that of the associated flames, stabilisation and mixing processes have shown to be extremely complex, three-dimensional and time dependent. The characteristics of the CRZ depend very strongly on the level of swirl (swirl number), burner configuration, type of flow expansion, Reynolds number (i.e. flowrate) and equivalence ratio. Although numerical methods have had some success when compared to experimental results, the models still have difficulties at medium to high swirl levels, with complex geometries and varied equivalence ratios. This study thus focuses on experimental results obtained to characterise the CRZ formed under varied combustion conditions with different geometries and some variation of swirl number in a generic swirl burner. CRZ behaviour has similarities to the equivalent isothermal state, but is strongly dependent on equivalence ratio, with interesting effects occurring with a high-velocity fuel injector. Partial premixing and combustion cause more substantive changes to the CRZ than pure diffusive combustion. (orig.)

  4. Highly stabilized partially premixed flames of propane in a concentric flow conical nozzle burner with coflow

    KAUST Repository

    Elbaz, Ayman M.; Senosy, M.S.; Zayed, M.F.; Roberts, William L.; Mansour, M.S.

    2018-01-01

    . Regardless the value of Φ, increasing the coflow velocity improves the flame stability. The correlation between recessed distance of the burner tubes and the fluctuation of the mixture fraction, Δξ, shows that at Δξ around 40% of the flammability limits leads

  5. Gaseous emissions from burning diesel, crude and prime bleachable summer yellow cottonseed oil in a burner for drying seedcotton

    International Nuclear Information System (INIS)

    Holt, G.A.; Hooker, J.D.

    2004-01-01

    Cottonseed oil has been used as a fuel source either as a blend with diesel in varying proportions or undiluted (100 %) in numerous studies evaluating its potential use in internal combustion engines. However, limited research is available on the use of cottonseed oil as a fuel source in a multi-fueled burner similar to those used by cottonseed oil mills and cotton gins in their drying operations. The purpose of this study was to evaluate emissions from five fuel oil treatments while firing a multi-fueled burner in a setup similar to those used for drying operations of both cottonseed oil mills and cotton gins. For each treatment, gaseous emissions were measured while firing the burner at three fuel flow rates. The five fuel oil treatments evaluated were: (1) No.2 diesel at 28.3 deg C, (2) prime bleachable summer yellow (PBSY) cottonseed oil at 28.3 deg C (PBSY-28), (3) crude cottonseed oil at 28.3 deg C (Crude-28), (4) PBSY at 60 deg C (PBSY-60), and (5) crude at 60 deg C (Crude-60). Results indicate that PBSY treatments had the lowest overall emissions of all treatments. The other treatments varied in emission rates based on treatment and fuel flow rate. Preheating the oil to 60 deg C resulted in higher NO x emissions but displayed varying results in regards to CO. The CO emissions for the crude treatments were relatively unaffected by the 60 deg C preheat temperature whereas the preheated PBSY treatments demonstrated lower CO emissions. Overall, both cottonseed oils performed well in the multi-fueled burner and displayed a promising potential as an alternative fuel source for cottonseed oil mills and cotton gins in their drying operations. (Author)

  6. Cathalitic burners for residential gas appliances; Bruciatori catalitici di gas naturale per apparecchi domestici

    Energy Technology Data Exchange (ETDEWEB)

    Accornero, R.; Canci, F. [Italgas Spa, Rome (Italy)

    2000-12-01

    The growing interest for the rational use of natural gas as a primary source of energy and for the reduction of pollutant emissions from combustion processes has kindled, in recent years, a widespread interest in studies and experimental investigations on the use of premix burners (either ceramic or metallic) for heat generators in domestic applications. The present paper deals with the R and D activities developed in this field by Italgas, Politecnico di Torino (Dipartimento di Scienza dei Materiali ed Ingegneria Chimica) and Merloni TermoSanitari, (an Italian gas boiler manufacturer). The technology hereby presented aims at reducing the pollutants emissions (CO, NO{sub x}, HC) in a wide range of working regimes of the burner, typical of residential heat appliances. The positive results in a lab scale experimental pilot plant have been in some cases confirmed in experimental runs performed on boiler prototypes suitable for large scale industrial production. Some projects, financially supported by the European Community and involving, beyond the above mentioned partners, also other gas distribution companies, universities, research institutes and burner manufacturers, are currently in progress to further analyse the performance of these burners. [Italian] Il crescente interesse per l'uso razionale del gas naturale quale fonte energetica primaria e quale combustibile a basso impatto ambientale, ha suscitato, nei tempi piu' recenti, un vasto interesse per gli studi e per le ricerche nel settore dei bruciatori di gas di tipo a premiscelazione, siano essi in materiale ceramico che metallico, allo scopo di rendere praticabile la loro applicazione nei generatori di calore di tipo domestico. L'articolo descrive l'attivita' di R e S sviluppata da Italgas, Politecnico di Torino - Dipartimento di Scienza dei Materiali ed Ingegneria Chimica - e da Merloni TermoSanitari. La tecnologia sperimentata e' finalizzata alla riduzione delle emissioni di

  7. Safety aspects of Particle Bed Reactor plutonium burner system

    International Nuclear Information System (INIS)

    Powell, J.R.; Ludewig, H.; Todosow, M.

    1993-01-01

    An assessment is made of the safety aspects peculiar to using the Particle Bed Reactor (PBR) as the burner in a plutonium disposal system. It is found that a combination of the graphitic fuel, high power density possible with the PBR and engineered design features results in an attractive concept. The high power density potentially makes it possible to complete the plutonium burning without requiring reprocessing and remanufacturing fuel. This possibility removes two hazardous steps from a plutonium burning complex. Finally, two backup cooling systems depending on thermo-electric converters and heat pipes act as ultimate heat removal sinks in the event of accident scenarios which result in loss of fuel cooling

  8. A Metal Fuel Core Concept for 1000 MWt Advanced Burner Reactor

    International Nuclear Information System (INIS)

    Yang, W.S.; Kim, T.K.; Grandy, C.

    2007-01-01

    This paper describes the core design and performance characteristics of a metal fuel core concept for a 1000 MWt Advanced Burner Reactor. A ternary metal fuel form of U-TRU-Zr was assumed with weapons grade plutonium feed for the startup core and TRU recovered from LWR spent fuel for the recycled equilibrium core. A compact burner core was developed by trade-off between the burnup reactivity loss and TRU conversion ratio, with a fixed cycle length of one-year. In the startup core, the average TRU enrichment is 15.5%, the TRU conversion ratio is 0.81, and the burnup reactivity loss over a cycle is 3.6% Δk. The heavy metal and TRU inventories are 13.1 and 2.0 metric tons, respectively. The average discharge burnup is 93 MWd/kg, and the TRU consumption rate is 55.5 kg/year. For the recycled equilibrium core, the average TRU enrichment is 22.1 %, the TRU conversion ratio is 0.73, and the burnup reactivity loss is 2.2% Δk. The TRU inventory and consumption rate are 2.9 metric tons and 81.6 kg/year, respectively. The evaluated reactivity coefficients provide sufficient negative feedbacks. The control systems provide shutdown margins that are more than adequate. The integral reactivity parameters for quasi-static reactivity balance analysis indicate favorable passive safety features, although detailed safety analyses are required to verify passive safety behavior. (authors)

  9. The Impact of Variable Inlet Mixture Stratification on Flame Topology and Emissions Performance of a Premixer/Swirl Burner Configuration

    Directory of Open Access Journals (Sweden)

    P. Koutmos

    2012-01-01

    Full Text Available The work presents the assessment of a low emissions premixer/swirl burner configuration utilizing lean stratified fuel preparation. An axisymmetric, single- or double-cavity premixer, formed along one, two, or three concentric disks promotes propane-air premixing and supplies the combustion zone at the afterbody disk recirculation with a radial equivalence ratio gradient. The burner assemblies are operated with a swirl co-flow to study the interaction of the recirculating stratified flame with the surrounding swirl. A number of lean and ultra-lean flames operated either with a plane disk stabilizer or with one or two premixing cavity arrangements were evaluated over a range of inlet mixture conditions. The influence of the variation of the imposed swirl was studied for constant fuel injections. Measurements of turbulent velocities, temperatures, OH* chemiluminescence and gas analysis provided information on the performance of each burner set up. Comparisons with Large Eddy Simulations, performed with an 11-step global chemistry, illustrated the flame front interaction with the vortex formation region under the influence of the variable inlet mixture stratifications. The combined effort contributed to the identification of optimum configurations in terms of fuel consumption and pollutants emissions and to the delineation of important controlling parameters and limiting fuel-air mixing conditions.

  10. Combustion stability and thermal efficiency in a porous media burner for LPG cooking in the food industry using Al_2O_3 particles coming from grinding wastes

    International Nuclear Information System (INIS)

    Herrera, Bernardo; Cacua, Karen; Olmos-Villalba, Luis

    2015-01-01

    Cooking is one of the most thermal-energy consuming processes in the food industry and development of devices that contribute to decrease the consumption of fossil fuel is a matter of great importance. This decreasing in consumption can both enlarge competitiveness in the enterprises of this sector and reduce emissions of greenhouse gases and other toxic combustion by products such as, carbon monoxide and nitrogen oxides. A porous burner made of a bed of Al_2O_3 particles coming from grinding residues and combined with ceramic foam of SiSiC has been evaluated respect to Liquefied Petroleum Gas combustion stability and thermal efficiency for cooking in food industry. The results showed that for specific heat input rate lower than 154 kW/m"2, the upper and lower equivalence ratio on the stability limit follow approximately a linear trend, as well as the wide of the range of stability remains constant. But this trend is broken when higher heat input rate is applied. Also, every equivalence ratio for stable combustion was in the lean ratio and stoichiometric combustion values were not feasible because flashback occurred. Emissions of CO were in acceptable values lower than 25 ppm for specific heat input rate lower than 154 kW/m"2 but an important rising in the CO emissions could be seen when the burner worked at higher heat input rate due to a moderate lift-off and quenching on the surface of the burner. Thermal efficiency was calculated in two different working ways: the “radiation–convection” and “conduction”. Thermal efficiency in the “radiation–convection” was between 15.7% and 23.6%, which are lower than the average thermal efficiency of the conventional free-flame burner. But the “conduction” mode showed a significant advantage respect to free flame conventional burners, since it could improve the thermal efficiency between 7% and 14%. The improvement in efficiency and the possibility of interrupting the flow of fuel in a cyclical operation

  11. Molten salt burner fuel behaviour and treatment

    International Nuclear Information System (INIS)

    Ignatiev, V.V.; Zakirov, R.Y.; Grebenkine, K.F.

    2001-01-01

    The objective of this paper is to discuss the feasibility of molten salt reactor technology for treatment of Pu, minor actinides and fission products, when the reactor and fission product clean-up unit are planned as an integral system. This contribution summarises the available R and D which led to selection of the fuel compositions for the molten salt reactor of the TRU burner type (MSB). Special characteristics of behaviour of TRUs and fission products during power operation of MSB concepts are presented. The present paper briefly reviews the processing developments underlying the prior molten salt reactor programmes and relates them to the separation requirements of the MSB concept, including the permissible range of processing cycle times and removal times. Status and development needs in the thermodynamic properties of fluorides, fission product clean-up methods and container materials compatibility with the working fluids for the fission product clean-up unit are discussed. (authors)

  12. Formation of nitric oxide in an industrial burner measured by 2-D laser induced fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, A; Bombach, R; Kaeppeli, B [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    We have performed two-dimensional Laser Induced Fluorescence (2-D LIF) measurements of nitric oxide and hydroxyl radical distributions in an industrial burner at atmospheric pressure. The relative 2-D LIF data of NO were set to an absolute scale by calibration with probe sampling combined with gas analysis. (author) 3 figs., 7 refs.

  13. Nitrogen oxide formation as a function of the shape of the flame in an experimental gas burner. Stikstofoxidenvorming als functie van de vlamvorm bij experimentele gasbrander

    Energy Technology Data Exchange (ETDEWEB)

    Hulshof, H J.M.; Thus, A W

    1992-01-01

    One of the options to reduce the emission of NO[sub x] from gas-fired or coal-fired power plants is to develop new burners or to improve the control of existing burners. The purpose of this investigation is to develop a measuring method to control the combustion process in each burner of a gas-fired or coal-fired power plant concerning NO[sub x]-emission, a constant energy production and stability of the combustion. A passive spectroscopic measuring method was developed, in which use is made of the light, emitted by the flame. Based on the measured values the NO[sub x]-emissions and the shape of the flame were correlated. From the correlations it appears that flame shape and NO[sub x]-emissions correspond quite well

  14. Inherent safe fast breeder reactors and actinide burners, metallic fuel

    International Nuclear Information System (INIS)

    Dorner, S.; Schumacher, G.

    1991-04-01

    Nuclear power without breeder strategy uses the possibilities for the energy supply only to a small extend compared to the possibilities of fast breeder reactors, which offer an energy supply for thousands of years. Moreover, a fast neutron device offers the opportunity to run an actinide-burner that could improve the situation of waste management. Within this concept metallic fuel could play a key role. The present report shows some important aspects of the concept like the pyrometallic reprocessing, the behaviour of metallic fuel during a core meltdown accident and others. The report should contribute to the discussion of these problems and initialize further work

  15. Image-based spectroscopic sensor for the automatic control gas burners in the glass-processing industry. Multichannel spectral detection of flame emissions and multivariate analysis methods allow for optical quality monitoring and control of industrial burners; Bildgebende optische Spektralsensorik zur automatischen Regelung von Gasbrennern fuer die Glas verarbeitende Industrie. Durch mehrkanalige spektrale Aufnahmen der Flammenemission und multivariate Auswertemethoden kann die Qualitaet der Gasversorgung bei industriellen Brennern optisch ueberwacht und geregelt werden

    Energy Technology Data Exchange (ETDEWEB)

    Knetsch, R.; Arnold, W. [Herbert Arnold GmbH und Co. KG, Weilburg (Germany); Erfurth, F.; Scheibe, A.; Nyuyki, B.; Schmidt, W.D. [GMBU e.V., Jena (Germany). Fachsektion Photonik und Sensorik

    2009-07-01

    The precise composition of the combustion gas mixture of burners is essential for the maximum achievable flame temperature as well as for the economic use of raw material. We present a mobile device for optical flame analysis and optimization of gas supply for industrial burners. The relative fuel-oxygen-ratio can be assessed by means of spectral emission in the visible and UV region by factoring in the distribution of gas emissions along the flame. Based on spectral imaging technology our sensor allows for calculation of a flame index stating the quality of fuel supply. A laboratory sample of the flame sensor has been tested with different burners using natural gas and propane. The flame index has been determined successful for several fuel-oxygen-ratios. Practical experiments showed that uncomplicated software-based adaptation of the device to several burner configurations is possible.

  16. Clinical and Research Activities at the CATANA Facility of INFN-LNS: From the Conventional Hadrontherapy to the Laser-Driven Approach.

    Science.gov (United States)

    Cirrone, Giuseppe A P; Cuttone, Giacomo; Raffaele, Luigi; Salamone, Vincenzo; Avitabile, Teresio; Privitera, Giuseppe; Spatola, Corrado; Margarone, Daniele; Patti, Valeria; Petringa, Giada; Romano, Francesco; Russo, Andrea; Russo, Antonio; Sabini, Maria G; Scuderi, Valentina; Schillaci, Francesco; Valastro, Lucia M

    2017-01-01

    The CATANA proton therapy center was the first Italian clinical facility making use of energetic (62 MeV) proton beams for the radioactive treatment of solid tumors. Since the date of the first patient treatment in 2002, 294 patients have been successful treated whose majority was affected by choroidal and iris melanomas. In this paper, we report on the current clinical and physical status of the CATANA facility describing the last dosimetric studies and reporting on the last patient follow-up results. The last part of the paper is dedicated to the description of the INFN-LNS ongoing activities on the realization of a beamline for the transport of laser-accelerated ion beams for future applications. The ELIMED (ELI-Beamlines MEDical and multidisciplinary applications) project is introduced and the main scientific aspects will be described.

  17. Clinical and Research Activities at the CATANA Facility of INFN-LNS: From the Conventional Hadrontherapy to the Laser-Driven Approach

    Science.gov (United States)

    Cirrone, Giuseppe A. P.; Cuttone, Giacomo; Raffaele, Luigi; Salamone, Vincenzo; Avitabile, Teresio; Privitera, Giuseppe; Spatola, Corrado; Amico, Antonio G.; Larosa, Giuseppina; Leanza, Renata; Margarone, Daniele; Milluzzo, Giuliana; Patti, Valeria; Petringa, Giada; Romano, Francesco; Russo, Andrea; Russo, Antonio; Sabini, Maria G.; Schillaci, Francesco; Scuderi, Valentina; Valastro, Lucia M.

    2017-01-01

    The CATANA proton therapy center was the first Italian clinical facility making use of energetic (62 MeV) proton beams for the radioactive treatment of solid tumors. Since the date of the first patient treatment in 2002, 294 patients have been successful treated whose majority was affected by choroidal and iris melanomas. In this paper, we report on the current clinical and physical status of the CATANA facility describing the last dosimetric studies and reporting on the last patient follow-up results. The last part of the paper is dedicated to the description of the INFN-LNS ongoing activities on the realization of a beamline for the transport of laser-accelerated ion beams for future applications. The ELIMED (ELI-Beamlines MEDical and multidisciplinary applications) project is introduced and the main scientific aspects will be described. PMID:28971066

  18. Clinical and Research Activities at the CATANA Facility of INFN-LNS: From the Conventional Hadrontherapy to the Laser-Driven Approach

    Directory of Open Access Journals (Sweden)

    Giuseppe A. P. Cirrone

    2017-09-01

    Full Text Available The CATANA proton therapy center was the first Italian clinical facility making use of energetic (62 MeV proton beams for the radioactive treatment of solid tumors. Since the date of the first patient treatment in 2002, 294 patients have been successful treated whose majority was affected by choroidal and iris melanomas. In this paper, we report on the current clinical and physical status of the CATANA facility describing the last dosimetric studies and reporting on the last patient follow-up results. The last part of the paper is dedicated to the description of the INFN-LNS ongoing activities on the realization of a beamline for the transport of laser-accelerated ion beams for future applications. The ELIMED (ELI-Beamlines MEDical and multidisciplinary applications project is introduced and the main scientific aspects will be described.

  19. Parameter optimization through performance analysis of model based control of a batch heat treatment furnace with low NO x radiant tube burner

    International Nuclear Information System (INIS)

    Tiwari, Manish Kumar; Mukhopadhyay, Achintya; Sanyal, Dipankar

    2005-01-01

    A model based control structure for heat treating a 0.5% C steel slab in a batch furnace with low NO x radiant tube burner is designed and tested for performance to yield optimal parameter values using the model developed in the companion paper. Combustion is considered in a highly preheated and product gas diluted mode. Controlled combustion with a proposed arrangement for preheating and diluting the air by recirculating the exhaust gas that can be retrofitted with an existing burner yields satisfactory performance and emission characteristics. Finally, the effect of variable property considerations are presented and critically analyzed

  20. Modelling and exergoeconomic-environmental analysis of combined cycle power generation system using flameless burner for steam generation

    International Nuclear Information System (INIS)

    Hosseini, Seyed Ehsan; Barzegaravval, Hasan; Ganjehkaviri, Abdolsaeid; Wahid, Mazlan Abdul; Mohd Jaafar, M.N.

    2017-01-01

    Highlights: • Using flameless burner as a supplementary firing system after gas turbine is modeled. • Thermodynamic, economic and environmental analyses of this model are performed. • Efficiency of the plant increases about 6% and CO_2 emission decreases up to 5.63% in this design. • Available exergy for work production in both gas cycle and steam cycle increases in this model. - Abstract: To have an optimum condition for the performance of a combined cycle power generation, using supplementary firing system after gas turbine was investigated by various researchers. Since the temperature of turbine exhaust is higher than auto-ignition temperature of the fuel in optimum condition, using flameless burner is modelled in this paper. Flameless burner is installed between gas turbine cycle and Rankine cycle of a combined cycle power plant which one end is connected to the outlet of gas turbine (as primary combustion oxidizer) and the other end opened to the heat recovery steam generator. Then, the exergoeconomic-environmental analysis of the proposed model is evaluated. Results demonstrate that efficiency of the combined cycle power plant increases about 6% and CO_2 emission reduces up to 5.63% in this proposed model. It is found that the variation in the cost is less than 1% due to the fact that a cost constraint is implemented to be equal or lower than the design point cost. Moreover, exergy of flow gases increases in all points except in heat recovery steam generator. Hence, available exergy for work production in both gas cycle and steam cycle will increase in new model.

  1. Low void effect (CFV) core concept flexibility: from self-breeder to burner core - 15091

    International Nuclear Information System (INIS)

    Buiron, L.; Dujcikova, L.

    2015-01-01

    In the frame of the French strategy on sustainable nuclear energy, several scenarios consider fuel cycle transition toward a plutonium multi-recycling strategy in sodium cooled fast reactor (SFR). Basically, most of these scenarios consider the deployment of a 60 GWe SFR fleet in 2 steps to renew the French PWR fleet. As scenarios do investigate long term deployment configurations, some of them require tools for nuclear phase-out studies. Instead of designing new reactors, the adopted strategy does focus on adaptation of existing ones into burner configurations. This is what was done in the frame of the EFR project at the end of the 90's using the CAPRA approach (French acronym for Enhance Plutonium Consumption in Fast Reactor). The EFR burner configuration was obtained by inserting neutronic penalties inside the core (absorber material and/or diluent subassembly). Starting from the preliminary industrial image of a SFR 3600 MWth core based on Low Sodium Void concept (CFV in French), a 'CAPRA-like' approach has been studied. As the CFV self-breeding is ensured by fertile blankets, a first modification consisted in the substitution of the corresponding depleted uranium by 'inert' or absorber material leading to a 'natural burner' core with only small impacts on flux distribution. The next step forward CAPRA configuration was the substitution of 1/3 of the fuel pins by 'dummy' pins (MgO pellets). The small spectrum shift due to MgO material insertion leads to an increase Doppler constant which exceeds the value of the reference case. As the core sodium void worth value is conserved, the CFV CAPRA core 'safety' potential is quite similar to the one of the reference core. Fuel thermo-mechanical requirements are met by both nominal core power and fuel time residence reduction. However, these reduction factors are lower than those obtained for EFR core. The management of the enhanced reactivity swing is discussed

  2. Design and manufacture of an atmospheric burner of biogas with rural application; Diseno y construccion de un quemador atmosferico de biogas con aplicaciones rurales

    Energy Technology Data Exchange (ETDEWEB)

    Nunez Nunez, Jorge; Suarez Pacheco, Jose; Novelo Navarrete, Jose H; Soto Apolinar, Efrain [Universidad de Quintana Roo, Chetumal, Quintana Roo (Mexico)

    2000-07-01

    In this text it's resumed the methodology that was carried out to make an atmospheric burner of biogas, as the criteria that were taken in account in order to determine the main parameters of it. It introduces a synthesis of the stages of design and manufacture of the device. The utility of this type of burner increase the efficiency of the oxidation of the biogas compared with the use of conventional burners that aren't designed for this purpose. [Spanish] En este trabajo se resume la metodologia que se llevo a cabo para la construccion de un quemador de biogas tipo atmosferico, asi como los criterios que se tomaron para la determinacion de los parametros principales del mismo. Se presenta una sintesis de las etapas de diseno y manufactura del dispositivo. El uso de este tipo de quemadores aumenta la eficiencia de la oxidacion del biogas en comparacion con el uso de quemadores convencionales que no estan disenados para quemar biogas.

  3. A Modeling Tool for Household Biogas Burner Flame Port Design

    Science.gov (United States)

    Decker, Thomas J.

    Anaerobic digestion is a well-known and potentially beneficial process for rural communities in emerging markets, providing the opportunity to generate usable gaseous fuel from agricultural waste. With recent developments in low-cost digestion technology, communities across the world are gaining affordable access to the benefits of anaerobic digestion derived biogas. For example, biogas can displace conventional cooking fuels such as biomass (wood, charcoal, dung) and Liquefied Petroleum Gas (LPG), effectively reducing harmful emissions and fuel cost respectively. To support the ongoing scaling effort of biogas in rural communities, this study has developed and tested a design tool aimed at optimizing flame port geometry for household biogas-fired burners. The tool consists of a multi-component simulation that incorporates three-dimensional CAD designs with simulated chemical kinetics and computational fluid dynamics. An array of circular and rectangular port designs was developed for a widely available biogas stove (called the Lotus) as part of this study. These port designs were created through guidance from previous studies found in the literature. The three highest performing designs identified by the tool were manufactured and tested experimentally to validate tool output and to compare against the original port geometry. The experimental results aligned with the tool's prediction for the three chosen designs. Each design demonstrated improved thermal efficiency relative to the original, with one configuration of circular ports exhibiting superior performance. The results of the study indicated that designing for a targeted range of port hydraulic diameter, velocity and mixture density in the tool is a relevant way to improve the thermal efficiency of a biogas burner. Conversely, the emissions predictions made by the tool were found to be unreliable and incongruent with laboratory experiments.

  4. A burner for the combustion of spent tall oil soap

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, P.M.; Wong, J.K.; Moffatt, B.; Belanger, G. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy Technology Centre; Soriano, D. [Brais Malouin and Associates, Montreal, PQ (Canada)

    2003-07-01

    Efficiency in industrial processes applies both to the form of energy involved and the many by-products resulting from the process. Tall oil soap (TOS) is a white frothy substance created during the pulping process. It contains chemicals that can be extracted for use in other industries. The processing of TOS results in a product called spent TOS. This study examined the incineration process to derive process heat from the calorific value in spent TOS. Brais Malouin and Associates (BMA) proposed that an atomizing nozzle should be used for use with this liquid in an incinerating burner. The efficiency of atomization of spent TOS with the BMA nozzle was determined by the Canada Centre for Mineral and Energy Technology (CANMET), which also characterized the combustion in a simulated boiler situation. The combustion tests were performed in the Pilot-Scale Research Boiler at the CANMET Energy Technology Centre (CETC). Pre-heating was done with a number 2 oil flame. Flame stability was determined by observing the flame through sight ports and by measuring the gas in the furnace. The experiments showed that spent TOS could successfully burn with a number 2 oil, in a proportion of 81 spent TOS to 19 oil mass ratio. As the amount of spent TOS was increased, the amount of sulphur dioxide, nitrogen oxide (NOx) and carbon monoxide decreased. The number 2 fuel oil was responsible for the sulphur dioxide in the exhaust. It is believed that the reduction in the carbon monoxide in the exhaust is attributable to the water-gas shift reaction. As the proportion of spent TOS increased, it was shown that the amount of NOx in the exhaust decreased rapidly. A bluish-green molten deposit formed in the furnace near the burner came from copper and manganese found in the ash of the spent TOS. 7 refs., 7 tabs., 16 figs.

  5. Hybrid model predictive control applied to switching control of burner load for a compact marine boiler design

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Maciejowski, Jan

    2008-01-01

    This paper discusses the application of hybrid model predictive control to control switching between different burner modes in a novel compact marine boiler design. A further purpose of the present work is to point out problems with finite horizon model predictive control applied to systems for w...

  6. ASU nitrogen sweep gas in hydrogen separation membrane for production of HRSG duct burner fuel

    Science.gov (United States)

    Panuccio, Gregory J.; Raybold, Troy M.; Jamal, Agil; Drnevich, Raymond Francis

    2013-04-02

    The present invention relates to the use of low pressure N2 from an air separation unit (ASU) for use as a sweep gas in a hydrogen transport membrane (HTM) to increase syngas H2 recovery and make a near-atmospheric pressure (less than or equal to about 25 psia) fuel for supplemental firing in the heat recovery steam generator (HRSG) duct burner.

  7. Deposition stress effects on thermal barrier coating burner rig life

    Science.gov (United States)

    Watson, J. W.; Levine, S. R.

    1984-01-01

    A study of the effect of plasma spray processing parameters on the life of a two layer thermal barrier coating was conducted. The ceramic layer was plasma sprayed at plasma arc currents of 900 and 600 amps onto uncooled tubes, cooled tubes, and solid bars of Waspalloy in a lathe with 1 or 8 passes of the plasma gun. These processing changes affected the residual stress state of the coating. When the specimens were tested in a Mach 0.3 cyclic burner rig at 1130 deg C, a wide range of coating lives resulted. Processing factors which reduced the residual stress state in the coating, such as reduced plasma temperature and increased heat dissipation, significantly increased coating life.

  8. Burner rig alkali salt corrosion of several high temperature alloys

    Science.gov (United States)

    Deadmore, D. L.; Lowell, C. E.

    1977-01-01

    The hot corrosion of five alloys was studied in cyclic tests in a Mach 0.3 burner rig into whose combustion chamber various aqueous salt solutions were injected. Three nickel-based alloys, a cobalt-base alloy, and an iron-base alloy were studied at temperatures of 700, 800, 900, and 1000 C with various salt concentrations and compositions. The relative resistance of the alloys to hot corrosion attack was found to vary with temperature and both concentration and composition of the injected salt solution. Results indicate that the corrosion of these alloys is a function of both the presence of salt condensed as a liquid on the surface and of the composition of the gas phases present.

  9. Pulverized straw combustion in a low-NOx multifuel burner

    DEFF Research Database (Denmark)

    Mandø, Matthias; Rosendahl, Lasse; Yin, Chungen

    2010-01-01

    A CFD simulation of pulverized coal and straw combustion using a commercial multifuel burner have been undertaken to examine the difference in combustion characteristics. Focus has also been directed to development of the modeling technique to deal with larger non-spherical straw particles...... and to determine the relative importance of different modeling choices for straw combustion. Investigated modeling choices encompass the particle size and shape distribution, the modification of particle motion and heating due to the departure from the spherical ideal, the devolatilization rate of straw......, the influence of inlet boundary conditions and the effect of particles on the carrier phase turbulence. It is concluded that straw combustion is associated with a significantly longer flame and smaller recirculation zones compared to coal combustion for the present air flow specifications. The particle size...

  10. Comparison of heat transfer and soil impacts of air curtain burner burning and slash pile burning

    Science.gov (United States)

    Woongsoon Jang; Deborah S. Page-Dumroese; Han-Sup Han

    2017-01-01

    We measured soil heating and subsequent changes in soil properties between two forest residue disposal methods: slash pile burning (SPB) and air curtain burner (ACB). The ACB consumes fuels more efficiently and safely via blowing air into a burning container. Five burning trials with different fuel sizes were implemented in northern California, USA. Soil temperature...

  11. Behaviors of tribrachial edge flames and their interactions in a triple-port burner

    KAUST Repository

    Yamamoto, Kazuhiro

    2015-05-01

    In a triple-port burner, various non-premixed flames have been observed previously. Especially for the case with two lifted flames, such configuration could be suitable in studying interaction between two tribrachial flames. In the present study, the flame characteristics have been investigated numerically by adopting a reduced kinetic mechanism in the triple-port burner. Four different types of flame configurations, including two attached flames, inner lifted/outer attached flames, inner attached/outer lifted flames, and twin lifted flames, were successfully simulated depending on the flow conditions. The representative edge propagation speed of a single lifted flame or an upstream lifted flame in the case of twin lifted flames increased as the liftoff height became higher. In the twin lifted flames, the inner lifted flame was affected appreciably when the other flame was located further upstream such that the lifted flame located further downstream encountered the axial velocity acceleration induced by the gas expansion from the lifted flame located upstream, while thermal effects were not observed since the temperature of the incoming flow toward the lifted flame was not affected. A unique flip-flop behavior between the inner and outer flames, observed experimentally previously, was successfully captured in the simulation such that the inner lifted flame became attached to the nozzle as the liftoff height of the outer lifted flame grew higher with an increase in the outer air velocity.

  12. Development of a multi-fuel burner for operation with light oil, natural gas and low calorific value gas; Entwicklung eines Mehrstoffbrenners fuer Heizoel-, Erdgas- und Schwachgasbetrieb

    Energy Technology Data Exchange (ETDEWEB)

    Giese, Anne; Tali, Eren [Gas- und Waerme-Institut Essen e.V., Essen (Germany)

    2013-08-15

    In the course of the AiF research project 'Development of a multi-fuel burner for operation with natural gas, light oil and low calorific value gas (MSB)' (IGF Grant No. 16202 N), various burner concepts based on the principle of continuously staged air were developed, analysed by means of computational fluid dynamics, built, investigated experimentally and finally tested at a real biomass gasifier (plant). This article describes the results of this research project. (orig.)

  13. Characterisation of heat transfer and flame length in a semi-scale industrial furnace equipped with HiTAC burner

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, L.; Nehme, W.; Biswas, A.K.; Yang, W.; Blasiak, W.; Bertin, D. [Royal Institute of Technology, Stockholm (Sweden)

    2010-09-15

    This paper investigates the effects of multiple burner nozzles on the combustion characteristics, such as flame volume, heat transfer and NOx emission in a high temperature air combustion (HiTAC) industrial furnace. Experiments were carried out in one semi-industrial furnace located in Kungliga Tekniska Hogskolan (Stockholm, Sweden). Three different types of burners were tested, including both regenerative and recuperative types. Variable flame temperature and oxygen concentration were applied in experiments. Heat transfer characteristics of HiTAC are studied in this paper, and the influences of a variety of inertial fuel/air jets are investigated for both flame length and NOx emission. One improved correlation between chemical flame length and flame Froude number is established for HiTAC with manifold nozzles. NOx emission is also correlated to the flame Froude number. The HiTAC recirculation system effects on flame shape, NOx emission and heat transfer were also examined.

  14. The flow field structure of highly stabilized partially premixed flames in a concentric flow conical nozzle burner with coflow

    KAUST Repository

    Elbaz, Ayman M.; Zayed, M.F.; Samy, M.; Roberts, William L.; Mansour, Mohy S.

    2015-01-01

    The stability limits, the stabilization mechanism, and the flow field structure of highly stabilized partially premixed methane flames in a concentric flow conical nozzle burner with air co-flow have been investigated and presented in this work

  15. Effect of operating parameters of a burner of oxygen conversion on flame characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Glike, A P

    1980-01-01

    Combustion of high-calorie gases under pressure makes it possible to create compact fuel-burning devices. As applied to open-hearth furnaces, several types of these devices have been developed. The oxidizer used is oxygen, blowing, enriched with oxygen or compressed air. Reformation of natural gas in the chamber of the burner of oxygen conversion operating under pressure up to 2 kg-f/cm/sup 2/ makes it possible to obtain a high-temperature flame with satisfactory illumination without using mazut.

  16. Role of the outer-edge flame on flame extinction in nitrogen-diluted non-premixed counterflow flames with finite burner diameters

    KAUST Repository

    Chung, Yong Ho; Park, Daegeun; Park, Jeong; Kwon, Oh Boong; Yun, Jin Han; Keel, Sang In

    2013-01-01

    This study of nitrogen-diluted non-premixed counterflow flames with finite burner diameters investigates the important role of the outer-edge flame on flame extinction through experimental and numerical analyses. It explores flame stability diagrams

  17. Low NO{sub x} burner modifications to front-fired pulverized coal boilers

    Energy Technology Data Exchange (ETDEWEB)

    Broderick, R G; Wagner, M

    1998-07-01

    Madison Gas and Electric Blount Street Station Units 8 and 9 are Babcock and Wilcox pulverized coal fired and natural gas fired boilers. These boilers were build in the late 1950's and early 1960's with each boiler rated at 425,000 lb./hr of steam producing 50 MW of electricity. The boilers are rated at 9,500 F at 1,350 psig. Each unit is equipped with one Ljungstroem air heater and two B and W EL pulverizers. These units burn subbituminous coal with higher heating value of 10,950 Btu/LB on an as-received basis. The nitrogen content is approximately 1.23% with 15% moisture. In order to comply with the new Clean Air Act Madison Gas and Electric needs to reduce NO{sub x} on these units to less than .5 LB/mmBtu. Baseline NO{sub x} emissions on these units range between .8--.9 lb./mmBtu. LOIs average approximately 8%. Madison Gas and Electric contracted with RJM Corporation to modify the existing burners to achieve this objective. These modifications consisted of adding patented circumferentially and radially staged flame stabilizers, modifying the coal pipe, and replacing the coal impeller with a circumferentially staged coal spreader. RJM Corporation utilized computational fluid dynamics modeling in order to design the equipment to modify these burners. The equipment was installed during the March 1997 outage and start-up and optimization was conducted in April 1997. Final performance results and economic data will be included in the final paper.

  18. Impact of fuel quality and burner capacity on the performance of wood pellet stove

    OpenAIRE

    Petrović-Bećirović Sanja B.; Manić Nebojša G.; Stojiljković Dragoslava D.

    2015-01-01

    Pellet stoves may play an important role in Serbia in the future when fossil fuel fired conventional heating appliances are replaced by more efficient and environmentally friendly devices. Experimental investigation was conducted in order to examine the influence of wood pellet quality, as well as burner capacity (6, 8 and 10 kW), used in the same stove configuration, on the performance of pellet stove with declared nameplate capacity of 8 kW. The results o...

  19. Altitude Performance Characteristics of Tail-pipe Burner with Variable-area Exhaust Nozzle

    Science.gov (United States)

    Jansen, Emmert T; Thorman, H Carl

    1950-01-01

    An investigation was conducted in the NACA Lewis altitude wind tunnel to determine effect of altitude and flight Mach number on performance of tail-pipe burner equipped with variable-area exhaust nozzle and installed on full-scale turbojet engine. At a given flight Mach number, with constant exhaust-gas and turbine-outlet temperatures, increasing altitude lowered the tail-pipe combustion efficiency and raised the specific fuel consumption while the augmented thrust ratio remained approximately constant. At a given altitude, increasing flight Mach number raised the combustion efficiency and augmented thrust ratio and lowered the specific fuel consumption.

  20. Burner flow regulators with mechanisms performing two variable function. Meccanismi che generano una funzione di due variabili applicati alla regolazione dei bruciatori

    Energy Technology Data Exchange (ETDEWEB)

    Borelli, L.; Tagliaferro, B. (R.B.L. Riello Bruciatori, Legnago Spa, Legnago (Italy)); Cossalter, V.; Da Lio, M. (Padua Univ. (Italy). Dip. di Ingegneria Meccanica)

    1993-08-01

    A new class of fuel oil burners has recently been developed by an Italian firm with the aim of obtaining high performances in terms of both energy efficiency and air pollution abatement. The innovative feature of these burners is that they are equipped with a device which permits the automatic and optimum regulation of the air fuel mixture independent of ambient and operating conditions. To reduce costs, the regulation system is a mechanical one instead of electronic which would require an expensive lambda probe. The mechanical regulating system controls air intake by simply taking into account two main combustion factors - ambient temperature and the nominal fuel flow rate. The special cam mechanism is thus classified as one which performs a single function with two degrees of freedom, i.e., the independent variables of ambient temperature and nominal fuel flow. One of the air intake valve's movements is governed by a temperature transducer, the other (primary), by a screw which allows the registering of the air flow during burner installation or upon completion of periodic maintenance checks. In addition to optimizing combustion control, this control technique affords the possibility to adapt the air flow to the different fuel flows obtained by changing the type of nozzle or supply pressure.

  1. Investigation on Flame Characteristics and Burner Operability Issues of Oxy-Fuel Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Choudhuri, Ahsan [Univ. Of Texas, El Paso, TX (United States)

    2013-09-30

    Oxy-fuel combustion has been used previously in a wide range of industrial applications. Oxy- combustion is carried out by burning a hydrocarbon fuel with oxygen instead of air. Flames burning in this configuration achieve higher flame temperatures which present opportunities for significant efficiency improvements and direct capture of CO2 from the exhaust stream. In an effort to better understand and characterize the fundamental flame characteristics of oxy-fuel combustion this research presents the experimental measurements of flame stability of various oxyfuel flames. Effects of H2 concentration, fuel composition, exhaust gas recirculation ratio, firing inputs, and burner diameters on the flame stability of these fuels are discussed. Effects of exhaust gas recirculation i.e. CO2 and H2O (steam) acting as diluents on burner operability are also presented. The roles of firing input on flame stability are then analyzed. For this study it was observed that many oxy-flames did not stabilize without exhaust gas recirculation due to their higher burning velocities. In addition, the stability regime of all compositions was observed to decrease as the burner diameter increased. A flashback model is also presented, using the critical velocity gradient gF) values for CH4-O2-CO2 flames. The second part of the study focuses on the experimental measurements of the flow field characteristics of premixed CH4/21%O2/79%N2 and CH4/38%O2/72%CO2 mixtures at constant firing input of 7.5 kW, constant, equivalence ratio of 0.8, constant swirl number of 0.92 and constant Reynolds Numbers. These measurements were taken in a swirl stabilized combustor at atmospheric pressure. The flow field visualization using Particle Imaging Velocimetry (PIV) technique is implemented to make a better understanding of the turbulence characteristics of

  2. Swozzle based burner tube premixer including inlet air conditioner for low emissions combustion

    Science.gov (United States)

    Tuthill, Richard Sterling; Bechtel, II, William Theodore; Benoit, Jeffrey Arthur; Black, Stephen Hugh; Bland, Robert James; DeLeonardo, Guy Wayne; Meyer, Stefan Martin; Taura, Joseph Charles; Battaglioli, John Luigi

    2002-01-01

    A burner for use in a combustion system of a heavy-duty industrial gas turbine includes a fuel/air premixer having an air inlet, a fuel inlet, and an annular mixing passage. The fuel/air premixer mixes fuel and air into a uniform mixture for injection into a combustor reaction zone. The burner also includes an inlet flow conditioner disposed at the air inlet of the fuel/air premixer for controlling a radial and circumferential distribution of incoming air. The pattern of perforations in the inlet flow conditioner is designed such that a uniform air flow distribution is produced at the swirler inlet annulus in both the radial and circumference directions. The premixer includes a swozzle assembly having a series of preferably air foil shaped turning vanes that impart swirl to the airflow entering via the inlet flow conditioner. Each air foil contains internal fuel flow passages that introduce natural gas fuel into the air stream via fuel metering holes that pass through the walls of the air foil shaped turning vanes. By injecting fuel in this manner, an aerodynamically clean flow field is maintained throughout the premixer. By injecting fuel via two separate passages, the fuel/air mixture strength distribution can be controlled in the radial direction to obtain optimum radial concentration profiles for control of emissions, lean blow outs, and combustion driven dynamic pressure activity as machine and combustor load are varied.

  3. Numerical Investigation of the Low-Caloric Gas Burning Process in a Bottom Burner

    Directory of Open Access Journals (Sweden)

    Redko A.

    2017-08-01

    Full Text Available The use of low-grade gases in the fuel and energy balance of enterprises makes it possible to increase the energy efficiency of technological processes. The volumes of low-grade gases (blast furnace and coke oven gases, synthesis gas of coal gasification processes, biogas, coal gas, etc. that are utilized more significant in technological processes but their calorific value are low. At the same time artificial gases contain ballast gaseous (СО2, H2O and mechanical impurities that are harmful gas impurities. Their use requires technological preparation. Thus coal methane is characterized of high humidity, coal dust and drip moisture, variable composition. Thus was effective burning of coal methane it is required the development of constructive and regime measures that ensure a stable and complete burning of gaseous fuels. In this article it is presented the results of computer simulation of a stationary turbulent diffusion flame in a restricted space in the process of burning natural gas and coal methane in a bottom burner. The calculation results contain the fields of gear, temperature, concentration of CH4‚ CO‚ H2O‚ CO2 and nitrogen oxides. The structural elements of the flame (recirculation zone, hot "dome", mixing layer and far trace are determined. It has been established that complete combustion of coal methane in a modified bottom burner is ensured and the numerical values of nitrogen oxide concentrations in the flame are consistent with the literature data.

  4. Experimental study of a separated jets burner: application to the natural gas-pure oxygen combustion; Etude experimentale du comportement de bruleurs a jets separes: application a la combustion gaz naturel-oxygene pur

    Energy Technology Data Exchange (ETDEWEB)

    Salentey, L.

    2002-04-15

    The evolution of pollution standards and the optimisation of furnaces performances require a development of new burner generation and also the improvement of combustion techniques. Actually, the use of oxy-combustion in separated jets burners offers interesting prospects for NO{sub x} emission reduction and on the modularity of flames properties (lift off, flame front topology, flame length). The complex geometry of those burners leads to several problems like the three-dimensional character of the flow, which may sometimes disturb the flame stability as flames are lifted above the burner. This experimental study deals with a simplified version of that kind of burner constituted with a central natural gas jet surrounded by two oxygen jets. Primary, the study of non-reactive jet was planned in order to understand dynamic and mixture phenomena involved between jets and to provide a database useful for the computer code validation. The reactive flow developed in a furnace, which simulates the real conditions, had been characterised. The studies of the dynamic field using Laser Doppler Velocimetry (LDV) and of the turbulent mixture by conditional Laser tomography were supplemented in combustion by the visualisation of the spontaneous emission of radical OH, in the initial and final zone of the oxy-flames, like by the measurement of pollutants like NO{sub x} and soot. The measurements carried out while varying speeds of injection as well as the gap between the jets made possible the highlight of the influence of these parameters upon the stabilisation of the oxy-flames as well as the modification of the topology and the characteristics of the flows. The comparison of the measurements made in non-reactive and reactive flow shows the influence of oxy-combustion on the dynamic and scalar development of the flow for this type of burners. (author)

  5. Gas fired boilers: Perspective for near future fuel composition and impact on burner design process

    Science.gov (United States)

    Schiro, Fabio; Stoppato, Anna; Benato, Alberto

    2017-11-01

    The advancements on gas boiler technology run in parallel with the growth of renewable energy production. The renewable production will impact on the fuel gas quality, since the gas grid will face an increasing injection of alternative fuels (biogas, biomethane, hydrogen). Biogas allows producing energy with a lower CO2 impact; hydrogen production by electrolysis can mitigate the issues related to the mismatch between energy production by renewable and energy request. These technologies will contribute to achieve the renewable production targets, but the impact on whole fuel gas production-to-consumption chain must be evaluated. In the first part of this study, the Authors present the future scenario of the grid gas composition and the implications on gas fed appliances. Given that the widely used premixed burners are currently designed mainly by trial and error, a broader fuel gas quality range means an additional hitch on this design process. A better understanding and structuring of this process is helpful for future appliance-oriented developments. The Authors present an experimental activity on a premixed condensing boiler setup. A test protocol highlighting the burners' flexibility in terms of mixture composition is adopted and the system fuel flexibility is characterized around multiple reference conditions.

  6. Gas fired boilers: Perspective for near future fuel composition and impact on burner design process

    Directory of Open Access Journals (Sweden)

    Schiro Fabio

    2017-01-01

    Full Text Available The advancements on gas boiler technology run in parallel with the growth of renewable energy production. The renewable production will impact on the fuel gas quality, since the gas grid will face an increasing injection of alternative fuels (biogas, biomethane, hydrogen. Biogas allows producing energy with a lower CO2 impact; hydrogen production by electrolysis can mitigate the issues related to the mismatch between energy production by renewable and energy request. These technologies will contribute to achieve the renewable production targets, but the impact on whole fuel gas production-to-consumption chain must be evaluated. In the first part of this study, the Authors present the future scenario of the grid gas composition and the implications on gas fed appliances. Given that the widely used premixed burners are currently designed mainly by trial and error, a broader fuel gas quality range means an additional hitch on this design process. A better understanding and structuring of this process is helpful for future appliance-oriented developments. The Authors present an experimental activity on a premixed condensing boiler setup. A test protocol highlighting the burners' flexibility in terms of mixture composition is adopted and the system fuel flexibility is characterized around multiple reference conditions.

  7. Large Eddy Simulation of Flow Structures in the Sydney Swirl Burner

    DEFF Research Database (Denmark)

    Yang, Yang

    . The theories of LES and the corresponding closure models have been well developed. This research focuses on statistical analysing flow field and characteristic features. Validation studies show good agreement in the isothermal cases, while for the reacting case, the LES predictions are less satisfactory...... zone which starts at the burner surface. As for the medium swirling isothermal case, there are two reverse flow zones in the reacting case. Due to the low stoichiometric mixture fraction in the methane flame, only the outer layer of the bluff‐body induced reverse zone is reactive. The main reactive...... method strategy has limitations concerning wall bounded flows, especially for complex geometries typically found in industry. Multi‐phase flows need special treatment....

  8. Fiscal 1999 survey report. Basic survey for promotion of joint implementations, etc. (Feasibility study of regenerative burner type heating furnaces for China's Shougang Corporation and Anshan Steel); 1999 nendo Chugoku shuto kotetsu Anshan kotetsu chikunetsu burner kanetsuro FS

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    Most of the steel heating furnaces now in operation in China are of the old type, consuming more than 40% more fuel than furnaces in general use for instance in Japan. In this survey, China's steel heating furnaces will be replaced by regenerative burners, developed in Japan recently and approaching practical application, for epoch-making enhancement of energy conservation and NOx reduction. Three plants are selected for study, which are the Shougang Corporation Plate Mill, the Qinhungdao Plate Mill, and the Anshan Steel Mill. Technical feasibility and economic profitability are studied for each of the projects for picking out projects that will link to CDM (clean development mechanism) in the future. In all the three mills, excellent energy conservation and economic profitability will result from technologically feasible introduction of regenerative burner heating furnaces. It is expected that their introduction will take place early enough. Full-scale diffusion of new furnaces will be dependent, however, on the progress of fuel gas cleaning study and China's assessment of the effects of energy conservation and environmental improvement. (NEDO)

  9. Numerical modeling of combustion of low-calorific-producer-gas from Mangium wood within a late mixing porous burner (LMPB

    Directory of Open Access Journals (Sweden)

    Kanokkarn Jirakulsomchok

    2017-08-01

    Full Text Available This article presents a numerical study of combustion of low-calorific-producer-gas from Mangium wood within a late mixing porous burner (LMPB. The LMPB consists of four main components, i.e., the fuel preheating porous (FP, the porous combustor (PC, the air jacket, and the mixing chamber. Interestingly, this LMPB was able to highly preheated and it still maintained high safety in operation. A single-step global reaction, steady state approach and a one-dimensional model were considered. The necessary information for burner characteristics, i.e., temperature profile, flame location and maximum temperature were also presented. The results indicated that stable combustion of a low-calorific-producer-gas within LMPB was possible achieved. Increasing equivalence ratio resulted in increasing in the flame temperature. Meanwhile, increasing the firing rate caused slightly decrease in flame temperature. The flame moved to downstream zone of the PC when the firing rate increased. Finally, it was found that the equivalence ratio did not affect the flame location.

  10. Experimental investigation on NO{sub x} emission and carbon burnout from a radially biased pulverized coal whirl burner

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Shan; Hui, Shi' en; Zhou, Qulan; Xu, Tongmo; Hu, Hongli [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Liu, Taisheng [Dongfang Boiler Group Co., Ltd., Zigong, Sichuan 643001 (China)

    2009-09-15

    Experiments have been performed on 1 MW pulverized coal (pc) furnace in order to investigate the characteristics of coal combustion and NO{sub x} emission from a new type of radially biased dual register whirl burner. The burner is characterized by a primary air pipe with a continuously changing cross-section and an impact ring. The mixture of pulverized coal and air inside the primary pipe is split into two streams, which are the outer pc rich annular jet and the inner pc lean annular jet respectively. Three Chinese coals, which are high rank bituminous coal, low rank bituminous coal and meager coal respectively, are used in the experiments. We examine the influences of various parameters such as the relative position of the over-fire air (OFA) nozzle, over-fire air ratio (19.1%), primary air ratio, inner secondary air ratio, outer secondary air ratio, inner secondary air swirling intensity, and outer secondary air swirling intensity on NO{sub x} formation and unburned carbon in fly ash. With the primary air ratio increasing from 13.4% to 23.4%, the value of the NO{sub x} emission of the SH coal decreases by 26.7% at first, and then increases by 21.7%. In contrast, the value of the carbon in fly ash (C{sub FA}) increases by 40.1% at first, and then decreases by 58.3%. According to the experimental results, the influence of each individual parameter on NO{sub x} formation and unburned carbon in fly ash agrees well with the existing literature. In this study, the influences of various combinations of these parameters are also examined, thus providing some reference for the design of the radial biased whirl burner, the configuration of the furnace and the distribution of the air. (author)

  11. Free of pollution gas - an utopia or attainable goal? Gas radiant burner with a small capacity

    International Nuclear Information System (INIS)

    Hofbauer, P.; Bornscheuer, W.

    1993-01-01

    The firm Viessmann has developed a gas radiant burner for boiler capacities up to 100 kN combusting gas with extremely low pollutant emissions. This is possible since from the reaction zone a considerable part of the combustion heat is delivered through radiation by means of a glowing special steel structure. The theoretical fundamentals are explained by means of considerations regarding the equilibrium and a reaction kinetic numerical model. (orig.) [de

  12. Efficiency of using direct-flow burners and nozzles in implementation of dry-bottom ash removal at the TPP-210A boiler furnace

    Science.gov (United States)

    Arkhipov, A. M.; Kanunnikov, A. A.; Kirichkov, V. S.; Prokhorov, V. B.; Fomenko, M. V.; Chernov, S. L.

    2017-02-01

    In reconstruction of operating pulverized coal-fired boilers, one of the main factors is the choice of a method for slag removal: dry bottom ash removal (DBAR) or slag-tap removal (STR). In this case, ecological and economic aspects should be taken into account, and also the early ignition of pulverized coal fuel, the reliability of operation of the furnace walls in the mode without slagging, and the stability of slag removal should be provided. In this work, issues of changeover of the pulverized coal-fired boilers of the TPP-210A type from the STR mode to the DBAR mode are considered. As of today, the main problems during the operation of these boilers are the high emissions of nitrogen oxides together with flue gases into the atmosphere and the appropriated payoffs, a small range of loads available, the necessity of stabilization of the pulverizedcoal flame sustainability by using the highly reactive fuel, large mechanical fuel underburning, etc. Results of studying aerodynamics of a furnace with DBAR obtained in the process of physical simulation are given; technical solutions and preliminary design (configuration of burners and nozzles in the boiler furnace, conceptual design of the pulverized coal burner, configuration of TPP-210A boiler with the low heat liberation of furnace cross-section and volumetric heat release) are set forth, which are associated with the optimization of aerodynamics of furnace volume, when the direct-flow burners and nozzles are used, and with organization of the efficient staged combustion of solid fuel. Two versions of possible modernization of a boiler unit are considered. Under conditions of the planned increase in the steam production capacity, the most promising measures are as follows: the DBAR implementation with reducing heat releases of the cross-section and volume of the furnace approximately by half, the installation of the direct-flow burners and nozzles with injection of recirculation gases into the active combustion

  13. Design comparisons of TRU burner cores with similar sodium void worth

    International Nuclear Information System (INIS)

    Sang Ji, Kim; Young Il, Kim; Young Jin, Kim; Nam Zin, Cho

    2001-01-01

    This study summarizes the neutronic performance and fuel cycle behavior of five geometrically-different transuranic (TRU) burner cores with similar low sodium void reactivity. The conceptual cores encompass core geometries for annular, two-region homogeneous, dual pin type, pan-shaped and H-shaped cores. They have been designed with the same assembly specifications and managed to have similar end-of-cycle sodium void reactivities and beginning-of-cycle peak power densities through the changes in the core size and configuration. The requirement of low sodium void reactivity is shown to lead each design concept to characteristic neutronics performance and fuel cycle behavior. The H-/pan-shaped cores allow the core compaction as well as higher rate of TRU burning. (author)

  14. Testing and Modeling Fuel Regression Rate in a Miniature Hybrid Burner

    Directory of Open Access Journals (Sweden)

    Luciano Fanton

    2012-01-01

    Full Text Available Ballistic characterization of an extended group of innovative HTPB-based solid fuel formulations for hybrid rocket propulsion was performed in a lab-scale burner. An optical time-resolved technique was used to assess the quasisteady regression history of single perforation, cylindrical samples. The effects of metalized additives and radiant heat transfer on the regression rate of such formulations were assessed. Under the investigated operating conditions and based on phenomenological models from the literature, analyses of the collected experimental data show an appreciable influence of the radiant heat flux from burnt gases and soot for both unloaded and loaded fuel formulations. Pure HTPB regression rate data are satisfactorily reproduced, while the impressive initial regression rates of metalized formulations require further assessment.

  15. Exposure calculation code module for reactor core analysis: BURNER

    Energy Technology Data Exchange (ETDEWEB)

    Vondy, D.R.; Cunningham, G.W.

    1979-02-01

    The code module BURNER for nuclear reactor exposure calculations is presented. The computer requirements are shown, as are the reference data and interface data file requirements, and the programmed equations and procedure of calculation are described. The operating history of a reactor is followed over the period between solutions of the space, energy neutronics problem. The end-of-period nuclide concentrations are determined given the necessary information. A steady state, continuous fueling model is treated in addition to the usual fixed fuel model. The control options provide flexibility to select among an unusually wide variety of programmed procedures. The code also provides user option to make a number of auxiliary calculations and print such information as the local gamma source, cumulative exposure, and a fine scale power density distribution in a selected zone. The code is used locally in a system for computation which contains the VENTURE diffusion theory neutronics code and other modules.

  16. Exposure calculation code module for reactor core analysis: BURNER

    International Nuclear Information System (INIS)

    Vondy, D.R.; Cunningham, G.W.

    1979-02-01

    The code module BURNER for nuclear reactor exposure calculations is presented. The computer requirements are shown, as are the reference data and interface data file requirements, and the programmed equations and procedure of calculation are described. The operating history of a reactor is followed over the period between solutions of the space, energy neutronics problem. The end-of-period nuclide concentrations are determined given the necessary information. A steady state, continuous fueling model is treated in addition to the usual fixed fuel model. The control options provide flexibility to select among an unusually wide variety of programmed procedures. The code also provides user option to make a number of auxiliary calculations and print such information as the local gamma source, cumulative exposure, and a fine scale power density distribution in a selected zone. The code is used locally in a system for computation which contains the VENTURE diffusion theory neutronics code and other modules

  17. Propagating nonpremixed edge-flames in a counterflow, annular slot burner under DC electric fields

    KAUST Repository

    Tran, Vu Manh

    2016-09-11

    Characteristics of propagating nonpremixed edge-flames were investigated in a counterflow, annular slot burner. A high-voltage direct current (DC) was applied to the lower part of the burner and the upper part was grounded, creating electric field lines perpendicular to the direction of edge-flame propagation. Upon application of an electric field, an ionic wind is caused by the migration of positive and negative ions to lower and higher electrical potential sides of a flame, respectively. Under an applied DC, we found a significant decrease in edge-flame displacement speeds unlike several previous studies, which showed an increase in displacement speed. Within a moderate range of field intensity, we found effects on flame propagation speeds to be negligible after correcting the flame displacement speed with respect to the unburned flow velocity ahead of the flame edge. This indicates that the displacement speed of an edge-flame strongly depends on ionic wind and that an electric field has little or no impact on propagation speed. The ionic wind also influenced the location of the stoichiometric contour in front of the propagating edge in a given configuration such that a propagating edge was relocated to the higher potential side due to an imbalance between ionic winds originating from positive and negative ions. In addition, we observed a steadily wrinkled flame following transient propagation of the edge-flame, a topic for future research. © 2016 The Combustion Institute

  18. Turbulent Non-Premixed Flames Stabilized on Double-Slit Curved Wall-Jet Burner with Simultaneous OH-Planar Laser-Induced Fluorescence and Particle Image Velocimetry Measurements

    KAUST Repository

    Mansour, Morkous S.

    2015-04-29

    A double-slit curved wall-jet (CWJ) burner utilizing a Coanda effect by supplying fuel and air as annular-inward jets over a curved surface was employed to investigate the stabilization characteristics and structure of propane/air turbulent non-premixed flames with varying global equivalence ratio and Reynolds number. Simultaneous time-resolved measurements of particle image velocimetry (PIV) and planar laser-induced fluorescence (PLIF) of OH radicals were conducted. The burner showed a potential of stable and non-sooting operation for relatively large fuel loading and overall rich conditions. Mixing characteristics in cold flow were first examined using an acetone fluorescence technique, indicating substantial transport between the fuel and air by exhibiting appreciable premixing conditions. PIV measurements revealed that the flow field consisted of a wall-jet region leading to a recirculation zone through flow separation, an interaction jet region resulting from the collision of annular-inward jets, followed by a merged-jet region. The flames were stabilized in the recirculation zone and, in extreme cases, only a small flame seed remained in the recirculation zone. Together with the collision of the slit jets in the interaction jet region, the velocity gradients in the shear layers at the boundaries of the annular jets generate the turbulence. Turbulent mean and rms velocities were influenced by the presence of the flame, particularly in the recirculation zone. Flames with a high equivalence ratio were found to be more resistant to local extinction and exhibited a more corrugated and folded nature, particularly at high Reynolds numbers. For flames with a low equivalence ratio, local quenching and re-ignition processes maintained flames in the merged jet region, revealing a strong intermittency, which was substantiated by the increased principal strain rates for these flames. © 2015 Taylor & Francis Group, LLC.

  19. ERA-Net Evaluation of technology status for small-scale combustion of pellets from new ash rich biomasses - combustion tests in residential burners

    Energy Technology Data Exchange (ETDEWEB)

    Roennbaeck, Marie; Johansson, Mathias; Frida Claesson

    2008-07-01

    In this project, pellets with higher ash content compared to the wood pellets used today on the Swedish market were tested in three domestic-scale burners. The tests were carried out based on EN 303-5. In the flue gas, combustion parameters as carbon monoxide, carbon dioxide, oxygen and hydro carbons were measured, and also more fuel specific parameters such as nitrogen oxides, sulphur dioxide, hydrogen chloride, total dust and particle mass- and number concentration. The dust (fly ash) and bottom ash were characterized chemically. The implications of high ash content on combustion performance are discussed in the report. Altogether five pellets with 8 mm diameter were tested: oilseed straw pellet, reed canary grass pellet (RCG), barley straw pellet, bark pellet and wood pellet. All fuels were dry ranging from 6.5-12 % moisture. The ash content varied from 0.3 weight-% dm in wood to 7.9 % in RCG. Barley straw has a noticeable low ash melting temperature, < 980 deg C, and could not be combusted in any of the burners. The nitrogen content varied nine times and sulphur more than 10 times. The chlorine content was very low in wood and bark and more than 20 times higher in oilseed and barley. The composition of inorganic species in the fuel ash was dominated by calcium, potassium and silica in wood, bark and oilseed pellet, while RCG and barley straw were dominated by silica. The three burners used were commercial and known to fulfil high quality requirements. Burner A is a pellet burner where fuel is supplied on top of the grate with no mechanical mean for moving bottom ash on the grate during combustion. Bottom ash is blown away, and any slag remaining on the grate is removed with a scrape before ignition. Burner B is an upward burning pellet burner where fuel and ash is pushed upwards and the glow bed is exposed to the surrounding combustion department. Burner C is a forward burning grain burner that pushes fuel and ash forwards, inside a cylinder. From the

  20. Interim design status and operational report for remote handling fixtures: primary and secondary burners

    International Nuclear Information System (INIS)

    Burgoyne, R.M.

    1976-12-01

    The HTGR reprocessing flowsheet consists of two basic process elements: (1) spent fuel crushing and burning and (2) solvent extraction. Fundamental to these elements is the design and development of specialized process equipment and support facilities. A major consideration of this design and development program is equipment maintenance: specifically, the design and demonstration of selected remote maintenance capabilities and the integration of these into process equipment design. This report documents the current status of the development of remote handling and maintenance fixtures for the primary and secondary burners

  1. Preliminary design and analysis on nuclear fuel cycle for fission-fusion hybrid spent fuel burner

    International Nuclear Information System (INIS)

    Chen Yan; Wang Minghuang; Jiang Jieqiong

    2012-01-01

    A wet-processing-based fuel cycle and a dry-processing were designed for a fission-fusion hybrid spent fuel burner (FDS-SFB). Mass flow of SFB was preliminarily analyzed. The feasibility analysis of initial loaded fuel inventory, recycle fuel fabrication and spent fuel reprocessing were preliminarily evaluated. The results of mass flow of FDS-SFB demonstrated that the initial loaded fuel inventory, recycle fuel fabrication and spent fuel reprocessing of nuclear fuel cycle of FDS-SFB is preliminarily feasible. (authors)

  2. Effect of the mixing fields on the stability and structure of turbulent partially premixed flames in a concentric flow conical nozzle burner

    KAUST Repository

    Mansour, Mohy S.; Elbaz, Ayman M.; Roberts, William L.; Senosy, Mohamed S.; Zayed, Mohamed F.; Juddoo, Mrinal; Masri, Assaad R.

    2016-01-01

    of partially premixed methane flames. The mixing field in a concentric flow conical nozzle (CFCN) burner with well-controlled mechanism of the mixing is investigated using Rayleigh scattering technique. The flame stability, structure and flow field of some

  3. The effect of orifice plate insertion on low NOx radial swirl burner performances (simulated variable area burner)

    International Nuclear Information System (INIS)

    Mohammad Nazri Mohd Jaafar

    2000-01-01

    The effect of inserting an outlet orifice plate of different sizes at the exit plane of the swirler outlet were studied for small radial swirler with fixed curves vanes. Tests were carried out using two different sizes flame tubes of 76 mm and 140 mm inside diameter, respectively and 330 mm in length. The system was fuelled via eight vane passage fuel nozzles of 3.5 mm diameter hole. This type of fuel injection helps in mixing the fuel and air better prior to ignition. Tests were carried out at 20 mm W.G. pressure loss which is representative of gas burners for domestic central heating system operating conditions. Tests were also carried out at 400 K preheated inlet air temperature and using only natural gas as fuel. The aim of the insertion of orifice plate was to create the swirler pressure loss at the swirler outlet phase so that the swirler outlet shear layer turbulence was maximize to assist with fuel/air mixing. For the present work, the smallest orifice plate exhibited a very low NO x emissions even at 0.7 equivalence ratio were NO x is well below 10 ppm corrected at 0% oxygen at dry basis. Other emissions such as carbon monoxide and unburned hydrocarbon were below 10 ppm and 100 ppm, respectively, over a wide range of operating equivalence ratios. The implies that good combustion was achieved using the smallest orifice plate. (Author)

  4. Oxidation of a Silica-Containing Material in a Mach 0.3 Burner Rig

    Science.gov (United States)

    Nguyen, QuynhGiao N.; Cuy, Michael D.; Gray, Hugh R. (Technical Monitor)

    2002-01-01

    A primarily silica-containing material with traces of organic compounds, as well as aluminum and calcium additions, was exposed to a Mach 0.3 burner rig at atmospheric pressure using jet fuel. The sample was exposed for 5 continuous hours at 1370 C. Post exposure x-ray diffraction analyses indicate formation of cristobalite, quartz, NiO and Spinel (Al(Ni)CR2O4). The rig hardware is composed of a nickel-based superalloy with traces of Fe. These elements are indicated in the energy dispersive spectroscopy (EDS) results. This material was studied as a candidate for high temperature applications under an engine technology program.

  5. Investigation of micro burner performance during porous media combustion for surface and submerged flames

    Science.gov (United States)

    Janvekar, Ayub Ahmed; Abdullah, M. Z.; Ahmad, Z. A.; Abas, Aizat; Hussien, Ahmed A.; Kataraki, Pramod S.; Mohamed, Mazlan; Husin, Azmi; Fadzli, Khairil

    2018-05-01

    Porous media combustion is considered to be one of the popular choice due to its tremendous advantages. Such type of combustion liberates not only super stable flame but also maintains emissions parameters below thresholds level. Present study incorporates reaction and preheat layer with discrete and foam type of materials respectively. Burner was made to run in ultra-lean mode. Optimum equivalence ratio was found out to be 0.7 for surface flame, while 0.6 during submerged flame condition. Maximum thermal efficiency was noted to be 81%. Finally, emissions parameters where recorded continuously to measure NOx and CO, which were under global limits.

  6. Numerical Simulation of Gas-Solid Two-Phase Flow for Four-Channels Pulverized Swirling Burner

    Directory of Open Access Journals (Sweden)

    Defu LI

    2013-05-01

    Full Text Available This article presents a mathematical model of cold gas-solid two-phase flow which is based on the cement rotary kiln in service. By altering the parameters of air supply system of four- channels pulverized burner, investigations are taken of that motion trajectory and particle distributions in the very turbulent field. The results show that motion trail of most particles in rotary kiln is a combination process of gradual diffusion and slow sedimentation; increasing internal flow velocity would aggravate coal particles to diffuse; external flow velocity should be controlled in a reasonable range.

  7. Experimentation and mathematical simulation of the operation of a 300-kW boiler, equipped with a progressive regulation or on/off burner

    Energy Technology Data Exchange (ETDEWEB)

    Anglesio, P [Politecnico di Torino, Italy; Perthuis, E

    1980-04-01

    The results of an experimental study undertaken during tests run with domestic fuel oil and natural gas, are described. Losses via wall surfaces and exhaust gases are determined, and according to variations in output with the effective power of the boiler and the advantage of progressive regulation mode operation, from the energy point of view, are demonstrated. The mathematical model developed is presented. Simulation is obtained by considering thermal transfers in the hearth, and then the exchanger of the boiler. For continuous operation, two programs are presented. The first is used for adjustment to experimental results. A third program simulates discontinuous operation. Theoretical results slightly overestimate actual output, but confirm the advantage of progressive regulation. The economic study shows that the excess cost of a progressive modulation type burner tends to direct choice towards a compromise, in the form of a dual-rate (high/low) type burner.

  8. Statistics of strain rates and surface density function in a flame-resolved high-fidelity simulation of a turbulent premixed bluff body burner

    Science.gov (United States)

    Sandeep, Anurag; Proch, Fabian; Kempf, Andreas M.; Chakraborty, Nilanjan

    2018-06-01

    The statistical behavior of the surface density function (SDF, the magnitude of the reaction progress variable gradient) and the strain rates, which govern the evolution of the SDF, have been analyzed using a three-dimensional flame-resolved simulation database of a turbulent lean premixed methane-air flame in a bluff-body configuration. It has been found that the turbulence intensity increases with the distance from the burner, changing the flame curvature distribution and increasing the probability of the negative curvature in the downstream direction. The curvature dependences of dilatation rate ∇ṡu → and displacement speed Sd give rise to variations of these quantities in the axial direction. These variations affect the nature of the alignment between the progress variable gradient and the local principal strain rates, which in turn affects the mean flame normal strain rate, which assumes positive values close to the burner but increasingly becomes negative as the effect of turbulence increases with the axial distance from the burner exit. The axial distance dependences of the curvature and displacement speed also induce a considerable variation in the mean value of the curvature stretch. The axial distance dependences of the dilatation rate and flame normal strain rate govern the behavior of the flame tangential strain rate, and its mean value increases in the downstream direction. The current analysis indicates that the statistical behaviors of different strain rates and displacement speed and their curvature dependences need to be included in the modeling of flame surface density and scalar dissipation rate in order to accurately capture their local behaviors.

  9. Characterization of ceramic ornaments of a theatre-like incense burner

    International Nuclear Information System (INIS)

    Lopez-Valenzuela, R.; Lopez-Palacios, J.A.; Jimenez-Reyes, M.; Tenorio, D.; Catano, G.

    2010-01-01

    Thirteen Teotihuacan-style ornaments of an incense burner were studied. Ceramic pastes, pigments and mica were analyzed by neutron activation, X-ray diffraction and scanning electron microscopy. Elemental (Sc, Cr, Fe, Co, Rb, Cs, La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Hf, Th and U) and statistical analyses of ceramic-body data showed that these pieces were made from the same raw material, which is chemically different from the fine orange ceramic of Teotihuacan. Montmorillonite and the classical components of sand were the minerals identified in the ceramic pastes. The white pigment contained calcium, titanium and aluminium, the yellow pigment was ocher, and the red pigment was a mixture of red ocher and cinnabar, the binder of the pigments being clay. Exoskeletons of diatoms and locust ootecs were found in the pigments. Mica was identified as biotite, identical with that coming from Monte Alban Oaxaca. We wish to undertake a historical reconstruction of these ornaments based on archaeometric and literature data. (author)

  10. Deposition stress effects on the life of thermal barrier coatings on burner rigs

    Science.gov (United States)

    Watson, J. W.; Levine, S. R.

    1984-01-01

    A study of the effect of plasma spray processing parameters on the life of a two layer thermal barrier coating was conducted. The ceramic layer was plasma sprayed at plasma arc currents of 900 and 600 amps onto uncooled tubes, cooled tubes, and solid bars of Waspalloy in a lathe with 1 or 8 passes of the plasma gun. These processing changes affected the residual stress state of the coating. When the specimens were tested in a Mach 0.3 cyclic burner rig at 1130 deg C, a wide range of coating lives resulted. Processing factors which reduced the residual stress state in the coating, such as reduced plasma temperature and increased heat dissipation, significantly increased coating life.

  11. Transient change in the shape of premixed burner flame with the superposition of pulsed dielectric barrier discharge

    OpenAIRE

    Zaima, Kazunori; Sasaki, Koichi

    2016-01-01

    We investigated the transient phenomena in a premixed burner flame with the superposition of a pulsed dielectric barrier discharge (DBD). The length of the flame was shortened by the superposition of DBD, indicating the activation of combustion chemical reactions with the help of the plasma. In addition, we observed the modulation of the top position of the unburned gas region and the formations of local minimums in the axial distribution of the optical emission intensity of OH. These experim...

  12. ASSESSMENT OF THE USE FOR FERTILISATION PURPOSES INCINERATION ASH PELLETS USING GASIFICATION BURNER LESTER

    Directory of Open Access Journals (Sweden)

    Marzena Gibczyńska

    2016-12-01

    Full Text Available The use of biomass in system energetics for the purpose of increasing the share of renewable energy sources in the overall energy mix by biomass and coal co-combustion is not an optimal solution in the light of previous experience in Poland. It is appropriate to develop local biomass market for energy purposes as a basis for future distributed energy generation based on biomass. This solution facilitates the use of ash from biomass combustion for plant fertilisation. The present paper concerns the assessment of the use of ash from combustion of pellets in an innovative gasifying pellet burner – LESTER type, for soil fertilisation. The paper presents the analysis of the content of macro- and microelements in ash against the chemical composition of pellets in relation to permissible contents in fertilisers. The content of phosphorus, potassium, calcium and magnesium in bottom and fly ash from combustion of wood pellet and rye straw in LESTER gasifying burner validates the use of this material for soil fertilisation purposes. However, due to low nitrogen content – comparable to that found in soil, the material is not to be considered as fertiliser supplying this macroelement to soil. The analysed bottom ash used for fertilisation meets the conditions set out in the Regulation of the Minister of Environment of 9 September 2002. However, fly ash should be used with considerable caution due to high content of iron, zinc and nickel. The yield of bottom ash is several times higher than that of fly ash, therefore the possibility of its use in the form of mixtures in adequate proportions should be considered.

  13. Experiment research of slag renovation in the corner-fired boiler

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Zhijun; Wu, Wenfei [Inner Mongolia Univ. of Science and Technology, Baotou (China). School of Energy and Environment

    2013-07-01

    Aiming at serious slag on the water wall around the burner of corner-fired boiler with low-ash-fusion-point coal, cold experimental model has been established. In this experiment, particle image velocimetry (PIV) has been employed to accurately measure aerodynamic field of burner region, and the experimental research of furnace slag renovation has been conducted through changing the burner jet arrangement. The experiment results show that it has significantly effect on aerodynamic field in the furnace by changing burner jet deflection angle. A reasonable actual tangential circle diameter can be formed through adjusting the burner jet deflection angle, to prevent primary air attacking the wall, and further more, to effectively prevent serious slag on the water wall around the burner.

  14. Premixing hydrogen burners for surface refinement of glass; Vormischende Wasserstoffbrenner zur Oberflaechenbearbeitung von Glas

    Energy Technology Data Exchange (ETDEWEB)

    Goerisch, Matthias [Linde AG, Linde Gas Deutschland, Nuernberg (Germany)

    2013-02-15

    As a result, inter alia, of unceasing globalisation, European glass producers in practically all sectors - flat glass, container glass, crystal glass and special glasses - are faced with ever tougher competition from Asia. In the 2012 to 2015 period and beyond, the principal focuses in the manufacture of glass products will again be on reducing overall production costs and increasing process efficiency wherever possible, on greater productivity and on enhanced product (surface) quality. To meet these challenges in the field of surface refinement and flame polishing of glass products as efficiently as possible, Linde AG/Linde Gases Division has developed premixing Hydropox {sup registered} burner technology for hydrogen/oxygen fuels. (orig.)

  15. Premixed Combustion of Coconut Oil on Perforated Burner

    Directory of Open Access Journals (Sweden)

    I.K.G. Wirawan

    2013-10-01

    Full Text Available Coconut oil premixed combustion behavior has been studied experimentally on perforated burner with equivalence ratio (φ varied from very lean until very rich. The results showed that burning of glycerol needs large number of air so that the laminar burning velocity (SL is the highest at very lean mixture and the flame is in the form of individual Bunsen flame on each of the perforated plate hole. As φ is increased the  SL decreases and the secondary Bunsen flame with open tip occurs from φ =0.54 at the downstream of perforated flame. The perforated flame disappears at φ = 0.66 while the secondary Bunsen flame still exist with SL increases following that of hexadecane flame trend and then extinct when the equivalence ratio reaches one or more. Surrounding ambient air intervention makes SL decreases, shifts lower flammability limit into richer mixture, and performs triple and cellular flames. The glycerol diffusion flame radiation burned fatty acids that perform cellular islands on perforated hole.  Without glycerol, laminar flame velocity becomes higher and more stable as perforated flame at higher φ. At rich mixture the Bunsen flame becomes unstable and performs petal cellular around the cone flame front. Keywords: cellular flame; glycerol; perforated flame;secondary Bunsen flame with open tip; triple flame

  16. Numerical modeling for flame dynamics and combustion processes in a two-sectional porous burner with a detailed chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Young Jun; Kim, Yong Mo [Hanyang University, Seoul (Korea, Republic of)

    2014-11-15

    A two-dimensional model with the detailed chemistry and variable transport properties has been applied to numerically investigate the combustion processes and flame dynamics in the bilayer porous burner. To account for the velocity transition and diffusion influenced by solid matrix, porosity terms are included in the governing equations. Heat transfer coefficient is calculated by Nusselt number to reflect the effect of gas velocity, pore diameter, and material properties. The detailed chemistry is based on GRI 2.11. Numerical results indicate that the present approach is capable of the essential features of the premixed combustion in the porous media in terms of the precise flame structure, pollutant formation, and stabilization characteristics. In this bilayer porous burner, the heat transferred from the downstream flame zone is conducted to the upstream flame region through the solid matrix. This heat transfer process through the solid matrix substantially influences the flame structure and stabilization characteristics in the porous media. The predicted results are compared with experimental data in terms of temperature for gaseous mixture and solid matrix, CO and NO emission level. Based on numerical results, a precise comparison has been made for the freely propagating premixed flames and the premixed flames with a porous media for various inlet velocities.

  17. Neutronics design study on a minor actinide burner for transmuting spent fuel

    International Nuclear Information System (INIS)

    Choi, Hang Bok

    1998-08-01

    A liquid metal reactor was designed for the primary purpose of burning the minor actinide waste from commercial light water reactors. The design was constrained to maintain acceptable safety performance as measured by the burnup reactivity swing, the doppler coefficient, and the sodium void worth. Sensitivity studies were performed for homogeneous and decoupled core designs, and a minor actinide burner design was determined to maximize actinide consumption and satisfy safety constraints. One of the principal innovations was the use of two core regions, with a fissile plutonium outer core and an inner core consisting only of minor actinides. The physics studies performed here indicate that a 1200 MWth core is able to transmute the annual minor actinide inventory of about 16 LWRs and still exhibit reasonable safety characteristics. (author). 34 refs., 22 tabs., 14 figs

  18. Experimental investigation and optimisation of burner systems for glass melting ends with regenerative air preheating. Final report; Experimentelle Untersuchung und Optimierung von Brennersystemen fuer Glasschmelzwannen mit regenerativer Luftvorwaermung. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Scherello, A.; Flamme, M.; Kremer, H.

    2000-02-15

    The project comprised experiments on burner systems for glass melting ends with regenerative air preheating for the purpose of optimisation. The experimental set-up was to reflect realistic conditions. In the first stage of the investigations, modern burner systems were installed in a GWI test facility and investigated. [German] Ziel des oben genannten Forschungsvorhabens war die Durchfuehrung experimenteller Untersuchungen von Brennersystemen fuer Glasschmelzwannen mit regenerativer Luftvorwaermung sowie deren Optimierung. Dazu war es notwendig, einen experimentellen Aufbau zu realisieren, mit dessen Hilfe die Stroemungs-, Mischungs- und Umsetzungsphaenomene von Glasschmelzoefen realistisch nachgestellt und aussagekraeftige Untersuchungen durchgefuehrt werden koennen. In einem ersten Untersuchungsschritt wurden moderne Brennerlanzen an der GWI-Versuchsanlage installiert und untersucht. (orig.)

  19. The effects of burner stabilization on Fenimore NO formation in low-pressure, fuel-rich premixed CH4/O2/N2 flames

    NARCIS (Netherlands)

    van Essen, Vincent; Sepman, Alexey; Mokhov, A. V.; Levinsky, H. B.

    We investigate the effects of varying the degree of burner stabilization on Fenimore NO formation in fuel-rich low-pressure flat CH4/O-2/N-2 flames. Towards this end, axial profiles of flame temperature and OH, NO and CH mole fractions are measured using laser-induced fluorescence (LIF). The

  20. Premix fuels study applicable to duct burner conditions for a variable cycle engine

    Science.gov (United States)

    Venkataramani, K. S.

    1978-01-01

    Emission levels and performance of a premixing Jet-A/air duct burner were measured at reference conditions representative of take-off and cruise for a variable cycle engine. In a parametric variation sequence of tests, data were obtained at inlet temperatures of 400, 500 and 600K at equivalence ratios varying from 0.9 to the lean stability limit. Ignition was achieved at all the reference conditions although the CO levels were very high. Significant nonuniformity across the combustor was observed for the emissions at the take-off condition. At a reference Mach number of 0.117 and an inlet temperature of 600K, corresponding to a simulated cruise condition, the NOx emission level was approximately 1 gm/kg-fuel.

  1. Energy-saving and reduing harmful substancing harmful substances in industrial furnaes of the steel industry and NF metal industry by the further development and optimisation of regenerator burners

    International Nuclear Information System (INIS)

    Flamme, M.; Kuhn, P.

    1992-01-01

    The rational use of energy is an important measure to reduce CO 2 emission. One possibility of reducing the energy demand is the increase of the combustion efficiency. There are high waste gas losses, particularly in the area of high temperature processes in the conversion of energy from the fuel into process heat. The many aspects of the task led to a divided execution of the research work. The Gas Heat Institute, apart from the co-ordination of the whole project, is mainly concerned with the burners of the regenerator burner system, while the Operating Research Institute is mainly busy with the regenerators and with the effects of the cyclically varying furnace temperature on the process. (orig./HW) [de

  2. Cooling Effectiveness Measurements for Air Film Cooling of Thermal Barrier Coated Surfaces in a Burner Rig Environment Using Phosphor Thermometry

    Science.gov (United States)

    Eldridge, Jeffrey I.; Shyam, Vikram; Wroblewski, Adam C.; Zhu, Dongming; Cuy, Michael D.; Wolfe, Douglas E.

    2016-01-01

    While the effects of thermal barrier coating (TBC) thermal protection and air film cooling effectiveness are usually studied separately, their contributions to combined cooling effectiveness are interdependent and are not simply additive. Therefore, combined cooling effectiveness must be measured to achieve an optimum balance between TBC thermal protection and air film cooling. In this investigation, surface temperature mapping was performed using recently developed Cr-doped GdAlO3 phosphor thermometry. Measurements were performed in the NASA GRC Mach 0.3 burner rig on a TBC-coated plate using a scaled up cooling hole geometry where both the mainstream hot gas temperature and the blowing ratio were varied. Procedures for surface temperature and cooling effectiveness mapping of the air film-cooled TBC-coated surface are described. Applications are also shown for an engine component in both the burner rig test environment as well as an engine afterburner environment. The effects of thermal background radiation and flame chemiluminescence on the measurements are investigated, and advantages of this method over infrared thermography as well as the limitations of this method for studying air film cooling are discussed.

  3. Achievement report for fiscal 1999 on project for supporting the formation of energy/environmental technology verification project. International joint verification research project (Verification project relative to ignition and NOx reduction using plasma sub-burner in pulverized coal-fired furnace); 1999 nendo plasma sabubana ni yoru bifuntan nenshoro ni okeru chakka oyobi NO{sub x} teigen gijutsu ni kansuru jissho project seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This project is executed through the cooperation of a Russian research institute, Akita Prefectural University, and the Ishikawajima-Harima Heavy Industries Co., Ltd. In the development of a plasma sub-burner and the basic research for its verification, a pulverized coal burning plasma sub-burner is designed and fabricated, a basic burning experiment is conducted for the plasma sub-burner, and plasma stabilization in a pulverized coal flow is simulated. In the verification study of the ignition by the plasma sub-burner in a pulverized coal-fired furnace, it is found that the newly-developed plasma sub-burner satisfies the prescribed operating conditions in the system and that the ignition of pulverized coal takes place across the air ratio range of 0.5-1.5 when pulverized coal is fed to the sub-burner. It is also found that NOx is reduced a great deal when a plasma operating on an orifice gas of air or nitrogen is generated in a gas which contains NOx. (NEDO)

  4. Increasing the speed of computational fluid dynamics procedure for minimization the nitrogen oxide polution from the premixed atmospheric gas burner

    Directory of Open Access Journals (Sweden)

    Fotev Vasko G.

    2017-01-01

    Full Text Available This article presents innovative method for increasing the speed of procedure which includes complex computational fluid dynamic calculations for finding the distance between flame openings of atmospheric gas burner that lead to minimal NO pollution. The method is based on standard features included in commercial computational fluid dynamic software and shortens computer working time roughly seven times in this particular case.

  5. From Bunsen Burners to Fuel Cells: Invoking Energy Transducers to Exemplify "Paths" and Unify the Energy-Related Concepts of Thermochemistry and Thermodynamics

    Science.gov (United States)

    Hladky, Paul W.

    2009-01-01

    The conversion of chemical energy entirely into thermal energy by Bunsen burners and into thermal energy and electrical energy by fuel cells of varying efficiencies illustrates different paths by which a chemical reaction can occur. Using the efficiency of producing electrical energy as a path label allows all of the energy-related quantities to…

  6. Characterization of Liquid Fuel Evaporation of a Lifted Methanol Spray Flame in a Vitiated Coflow Burner

    Science.gov (United States)

    Cabra, Ricardo; Dibble, Robert W.; Chen, Jyh-Yuan

    2002-01-01

    An experimental investigation of lifted spray flames in a coflow of hot, vitiated gases is presented. The vitiated coflow burner is a spray flame that issues into a coaxial flow of hot combustion products from a lean, premixed H2/Air flame. The spray flame in a vitiated coflow emulates the combustion that occurs in many advanced combustors without the detailed fluid mechanics. Two commercially available laser diagnostic systems are used to characterize the spray flame and to demonstrate the vitiated coflow burner's amenability to optical investigation. The Ensemble Particle Concentration and Size (EPCS) system is used to measure the path-average droplet size distribution and liquid volume fraction at several axial locations while an extractive probe instrument named the Real-time Fuel-air Analyzer (RFA) is used to measure the air to fuel ratio downstream of the spray nozzle with high temporal and spatial resolution. The effect of coflow conditions (stoichiometry) and dilution of the fuel with water was studied with the EPCS optical system. As expected, results show that water retards the evaporation and combustion of fuels. Measurements obtained by the RFA extractive probe show that while the Delavan manufactured nozzle does distribute the fuel over the manufacturer specified spray angle, it unfortunately does not distribute the fuel uniformly, providing conditions that may result in the production of unwanted NOx. Despite some limitations due to the inherent nature of the experimental techniques, the two diagnostics can be readily applied to spray flames in the vitiated coflow environment.

  7. LES and RANS modeling of pulverized coal combustion in swirl burner for air and oxy-combustion technologies

    International Nuclear Information System (INIS)

    Warzecha, Piotr; Boguslawski, Andrzej

    2014-01-01

    Combustion of pulverized coal in oxy-combustion technology is one of the effective ways to reduce the emission of greenhouse gases into the atmosphere. The process of transition from conventional combustion in air to the oxy-combustion technology, however, requires a thorough investigations of the phenomena occurring during the combustion process, that can be greatly supported by numerical modeling. The paper presents the results of numerical simulations of pulverized coal combustion process in swirl burner using RANS (Reynolds-averaged Navier–Stokes equations) and LES (large Eddy simulation) methods for turbulent flow. Numerical simulations have been performed for the oxyfuel test facility located at the Institute of Heat and Mass Transfer at RWTH Aachen University. Detailed analysis of the flow field inside the combustion chamber for cold flow and for the flow with combustion using different numerical methods for turbulent flows have been done. Comparison of the air and oxy-coal combustion process for pulverized coal shows significant differences in temperature, especially close to the burner exit. Additionally the influence of the combustion model on the results has been shown for oxy-combustion test case. - Highlights: • Oxy-coal combustion has been modeled for test facility operating at low oxygen ratio. • Coal combustion process has been modeled with simplified combustion models. • Comparison of oxy and air combustion process of pulverized coal has been done. • RANS (Reynolds-averaged Navier–Stokes equations) and LES (large Eddy simulation) results for pulverized coal combustion process have been compared

  8. A computer simulation of the transient response of a 4 cylinder Stirling engine with burner and air preheater in a vehicle

    Science.gov (United States)

    Martini, W. R.

    1981-01-01

    A series of computer programs are presented with full documentation which simulate the transient behavior of a modern 4 cylinder Siemens arrangement Stirling engine with burner and air preheater. Cold start, cranking, idling, acceleration through 3 gear changes and steady speed operation are simulated. Sample results and complete operating instructions are given. A full source code listing of all programs are included.

  9. PASSIVE CONTROL OF PARTICLE DISPERSION IN A PARTICLE-LADEN CIRCULAR JET USING ELLIPTIC CO-ANNULAR FLOW: A MEANS FOR IMPROVING UTILIZATION AND EMISSION REDUCTIONS IN PULVERIZED COAL BURNER

    Energy Technology Data Exchange (ETDEWEB)

    Ahsan R. Choudhuri

    2003-06-01

    A passive control technology utilizing elliptic co-flow to control the particle flinging and particle dispersion in a particle (coal)-laden flow was investigated using experimental and numerical techniques. Preferential concentration of particles occurs in particle-laden jets used in pulverized coal burner and causes uncontrollable NO{sub x} formation due to inhomogeneous local stoichiometry. This particular project was aimed at characterizing the near-field flow behavior of elliptic coaxial jets. The knowledge gained from the project will serve as the basis of further investigation on fluid-particle interactions in an asymmetric coaxial jet flow-field and thus is important to improve the design of pulverized coal burners where non-homogeneity of particle concentration causes increased NO{sub x} formation.

  10. Mach 0.3 Burner Rig Facility at the NASA Glenn Materials Research Laboratory

    Science.gov (United States)

    Fox, Dennis S.; Miller, Robert A.; Zhu, Dongming; Perez, Michael; Cuy, Michael D.; Robinson, R. Craig

    2011-01-01

    This Technical Memorandum presents the current capabilities of the state-of-the-art Mach 0.3 Burner Rig Facility. It is used for materials research including oxidation, corrosion, erosion and impact. Consisting of seven computer controlled jet-fueled combustors in individual test cells, these relatively small rigs burn just 2 to 3 gal of jet fuel per hour. The rigs are used as an efficient means of subjecting potential aircraft engine/airframe advanced materials to the high temperatures, high velocities and thermal cycling closely approximating actual operating environments. Materials of various geometries and compositions can be evaluated at temperatures from 700 to 2400 F. Tests are conducted not only on bare superalloys and ceramics, but also to study the behavior and durability of protective coatings applied to those materials.

  11. The influence of droplet evaporation on fuel-air mixing rate in a burner

    Science.gov (United States)

    Komiyama, K.; Flagan, R. C.; Heywood, J. B.

    1977-01-01

    Experiments involving combustion of a variety of hydrocarbon fuels in a simple atmospheric pressure burner were used to evaluate the role of droplet evaporation in the fuel/air mixing process in liquid fuel spray flames. Both air-assist atomization and pressure atomization processes were studied; fuel/air mixing rates were determined on the basis of cross-section average oxygen concentrations for stoichiometric overall operation. In general, it is concluded that droplets act as point sources of fuel vapor until evaporation, when the fuel jet length scale may become important in determining nonuniformities of the fuel vapor concentration. In addition, air-assist atomizers are found to have short droplet evaporation times with respect to the duration of the fuel/air mixing process, while for the pressure jet atomizer the characteristic evaporation and mixing times are similar.

  12. Highly stabilized partially premixed flames of propane in a concentric flow conical nozzle burner with coflow

    KAUST Repository

    Elbaz, Ayman M.

    2018-01-11

    Partially premixed turbulent flames with non-homogeneous jet of propane were generated in a concentric flow conical nozzle burner in order to investigate the effect of the coflow on the stability and flame structure. The flame stability is first mapped and then high-speed stereoscopic particle image velocimetry, SPIV, plus OH planar laser-induced fluorescence, OH-PLIF, measurements were conducted on a subset of four flames. The jet equivalence ratio Φ = 2, Jet exit Reynolds number Re = 10,000, and degree of premixing are kept constant for the selected flames, while the coflow velocity, Uc, is progressively changed from 0 to 15 m/s. The results showed that the flame is stable between two extinction limits of mixture inhomogeneity, and the optimum stability is obtained at certain degree of mixture inhomogeneity. Increasing Φ, increases the span between these two extinction limits, while these limits converge to a single point (corresponding to optimum mixture inhomogeneity) with increasing Re. Regardless the value of Φ, increasing the coflow velocity improves the flame stability. The correlation between recessed distance of the burner tubes and the fluctuation of the mixture fraction, Δξ, shows that at Δξ around 40% of the flammability limits leads to optimum flame stability. The time averaged SPIV results show that the coflow induces a big annular recirculation zone surrounds the jet flames. The size and the location of this zone is seen to be sensitive to Uc. However, the instantaneous images show the existence of a small vortical structure close to the shear layer, where the flame resides there in the case of no-coflow. These small vertical structures are seen playing a vital role in the flame structure, and increasing the flame corrugation close to the nozzle exit. Increasing the coflow velocity expands the central jet at the expense of the jet velocity, and drags the flame in the early flame regions towards the recirculation zone, where the flame tracks

  13. Experiential study on temperature and emission performance of micro burner during porous media combustion

    Science.gov (United States)

    Janvekar, Ayub Ahmed; Abdullah, M. Z.; Ahmad, Z. A.; Abas, A.; Ismail, A. K.; Hussien, A. A.; Kataraki, P. S.; Ishak, M. H. H.; Mazlan, M.; Zubair, A. F.

    2018-05-01

    Addition of porous materials in reaction zone give rise to significant improvements in combustion performance. In this work, a dual layered micro porous media burner was tested for stable flame and emissions. Reaction and preheat layer was made up of discrete (zirconia) and foam (porcelain) type of materials respectively. Three different thickness of reaction zone was tested, each with 10, 20 and 30mm. Interestingly, only 20mm thick layer can able to show better thermal efficiency of 72% as compared to 10 and 30mm. Best equivalence ratio came out to be 0.7 for surface and 0.6 for submerged flame conditions. Moreover, emission was continuously monitored to detect presence of NOx and CO, which were under controlled limits.

  14. Wood pellets for stoker burner

    International Nuclear Information System (INIS)

    Nykaenen, S.

    2000-01-01

    The author of this article has had a stoker for several years. Wood chips and sod peat has been used as fuels in the stoker, either separately or mixed. Last winter there occurred problems with the sod peat due to poor quality. Wood pellets, delivered by Vapo Oy were tested in the stoker. The price of the pellets seemed to be a little high 400 FIM/500 kg large sack. If the sack is returned in good condition 50 FIM deposit will be repaid to the customer. However, Vapo Oy informed that the calorific value of wood pellets is three times higher than that of sod peat so it should not be more expensive than sod peat. When testing the wood pellets in the stoker, the silo of the stoker was filled with wood pellets. The adjustments were first left to position used for sod peat. However, after the fire had ignited well, the adjustments had to be decreased. The content of the silo was combusted totally. The combustion of the content of the 400 litter silo took 4 days and 22 hours. Respectively combustion of 400 l silo of good quality sod peat took 2 days. The water temperature with wood pellets remained at 80 deg C, while with sod peat it dropped to 70 deg C. The main disadvantage of peat with small loads is the unhomogenous composition of the peat. The results of this test showed that wood pellets will give better efficiency than peat, especially when using small burner heads. The utilization of them is easier, and the amount of ash formed in combustion is significantly smaller than with peat. Wood pellets are always homogenous and dry if you do not spoil it with unproper storage. Pellets do not require large storages, the storage volume needed being less than a half of the volume needed for sod peat. When using large sacks the amount needed can even be transported at the trunk of a passenger car. Depending on the area to be heated, a large sack is sufficient for heating for 2-3 weeks. Filling of stoker every 2-5 day is not an enormous task

  15. Experimental Evaluation of a Low Emissions High Performance Duct Burner for Variable Cycle Engines (VCE)

    Science.gov (United States)

    Lohmann, R. P.; Mador, R. J.

    1979-01-01

    An evaluation was conducted with a three stage Vorbix duct burner to determine the performance and emissions characteristics of the concept and to refine the configuration to provide acceptable durability and operational characteristics for its use in the variable cycle engine (VCE) testbed program. The tests were conducted at representative takeoff, transonic climb, and supersonic cruise inlet conditions for the VSCE-502B study engine. The test stand, the emissions sampling and analysis equipment, and the supporting flow visualization rigs are described. The performance parameters including the fuel-air ratio, the combustion efficiency/exit temperature, thrust efficiency, and gaseous emissions calculations are defined. The test procedures are reviewed and the results are discussed.

  16. Investigation of pore-scale flow physics in porous media burners

    Science.gov (United States)

    Sobhani, Sadaf; Muhunthan, Priyanka; Boigne, Emeric; Mohaddes, Danyal; Ihme, Matthias; Stanford University Team

    2017-11-01

    Porous media burners (PMBs) operate on the principle that the solid porous matrix serves as a means of internally recirculating heat from the combustion products upstream to the reactants, enabling a reduction of the lean-flammability limit, higher power dynamic range, and lower NOx and CO emissions as compared to conventional systems. Accurate predictions of the flow features and properties such as pressure loss in reticulated ceramic foams is an important step in the characterization and optimization of combustion in porous media. In this work, an integrated framework is proposed from obtaining the porous sample to performing a computational fluid dynamics simulation, including X-ray microtomography scanning, digital topology rendering, and volume meshing. Three-dimensional numerical simulations of the flow in the complex geometries of porous foams are obtained by solution of the Navier-Stokes equations using an unstructured, finite-volume solver. This capability enables the investigation of pore-scale flow physics in a wide range of porous materials used in PMBs. In this talk, results obtained at pore-scale Reynolds numbers of order 10 to 100 in a Silicone Carbide foam are presented to demonstrate this capability.

  17. MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS

    Energy Technology Data Exchange (ETDEWEB)

    E.G. Eddings; A. Molina; D.W. Pershing; A.F. Sarofim; K.A. Davis; M.P. Heap; T.H. Fletcher; H. Zhang

    2000-04-01

    Reduction of NO{sub x} emission is an important environmental issue in pulverized coal combustion. The most cost-effective approach to NO{sub x} reduction is air-staging which can also operate with additional down-stream techniques such as reburning [1]. Air staging promotes the conversion of NO{sub x} precursors (HCN, NH{sub 3}, etc.) to N{sub 2} by delaying the oxygen supply to the greatest extent when those nitrogen species are released during devolatilization. Such a delay gives the primary volatiles a chance to undergo secondary reactions, including tar cracking and soot formation. Secondary reactions of volatiles largely determine the fate of the ultimate NO{sub x} production from pyrolysis, therefore a detailed investigation into the transformation of nitrogen species during secondary reactions and effects of soot on nitrogen release is critical for design and implementation of new pollution control strategies. Current nitrogen models (including the CPD model at BYU) only simulate the nitrogen release during primary pyrolysis, which happens at low temperatures. This project helps to build a nitrogen release model that accounts for secondary reactions and the effects of soot at temperatures relevant to industrial burners.

  18. Multi-load Optimal Design of Burner-inner-liner Under Performance Index Constraint by Second-Order Polynomial Taylor Series Method

    Directory of Open Access Journals (Sweden)

    Tu Gaoqiao

    2016-01-01

    Full Text Available Using maximum expansion pressure of n-decane, the aeroengine burner-inner-liner combustion pressure load is computed. Aerodynamic loads are obtained from internal gas pressure load and gas momentum. Multi-load second-order Taylor series equations are established using multi-variant polynomials and their sensitivities. Optimal designs are carried out using various performance index constraints. When 0.25 to 0.8 rectifications of different design variants are implemented, they converge under 5×10‒4 d-norm difference ratio.

  19. Assessment of Startup Fuel Options for the GNEP Advanced Burner Reactor (ABR)

    Energy Technology Data Exchange (ETDEWEB)

    Jon Carmack (062056); Kemal O. Pasamehmetoglu (103171); David Alberstein

    2008-02-01

    The Global Nuclear Energy Program (GNEP) includes a program element for the development and construction of an advanced sodium cooled fast reactor to demonstrate the burning (transmutation) of significant quantities of minor actinides obtained from a separations process and fabricated into a transuranic bearing fuel assembly. To demonstrate and qualify transuranic (TRU) fuel in a fast reactor, an Advanced Burner Reactor (ABR) prototype is needed. The ABR would necessarily be started up using conventional metal alloy or oxide (U or U, Pu) fuel. Startup fuel is needed for the ABR for the first 2 to 4 core loads of fuel in the ABR. Following start up, a series of advanced TRU bearing fuel assemblies will be irradiated in qualification lead test assemblies in the ABR. There are multiple options for this startup fuel. This report provides a description of the possible startup fuel options as well as possible fabrication alternatives available to the program in the current domestic and international facilities and infrastructure.

  20. Sonographic appearance of cervical lymphadenopathy due to infectious mononucleosis in children and young adults

    International Nuclear Information System (INIS)

    Fu, X.S.; Guo, L.M.; Lv, K.; Wang, L.; Ran, W.Q.; Tan, Q.T.; Wang, J.R.; Liu, X.

    2014-01-01

    Aim: To depict the grey-scale and Doppler features of cervical lymphadenopathy due to infectious mononucleosis (IM) and to compare the findings with other benign conditions and lymphoma. Materials and methods: One hundred and four patients <30 years old with 138 enlarged lymph nodes (LNs) were enrolled for sonographic analysis. These LNs were grouped as: IM LNs (59 LNs in 30 patients), lymphoma (30 LNs in 30 patients), bacterial lymphadenitis (24 LNs in 20 patients), tuberculosis (TB; 14 LNs in 13 patients), and reactive hyperplasia (11 LNs in 11 patients). Sonographic assessments included shape, echotexture, hilum, border, matting, cystic necrosis, calcification, and vascular pattern. For each sonographic feature, Fisher's exact test was performed to determine whether the difference between IM LNs and any another aetiology were statistically significant. Results: IM LNs tended to be round in shape (69%), heterogeneous in echotexture (61%), absent of echogenic hilum (66%), indistinct margins (80%), bilateral distribution (91%), and matting (83%) [even bilateral matting (66%)], and central hilar vascularity (89.8%). On analysis, bilateral matting had the highest specificity to IM LNs; however, its sensitivity was relatively low. In contrast to IM LNs, TB LNs were more likely to have unilateral matting, cystic necrosis, and calcification. Indistinct margins and decreased echogenicity of the hilum were more frequently seen in IM LNs than in bacterial LNs. Furthermore, central hilar vascularity was a common feature of IM LNs and other benignity, which can distinguish these from lymphoma and TB LNs. Conclusion: Although an individual sonographic feature had considerable overlaps between IM LNs and other aetiologies, the combination of several features may be helpful in the diagnosis of IM

  1. Kecepatan Pembakaran Premixed Campuran Minyak Jarak - Liquefied Petroleum Gas (LPG pada Circular Tube Burner

    Directory of Open Access Journals (Sweden)

    Defmit B.N. Riwu

    2016-10-01

    Full Text Available This study was conducted to determine the characteristics of premixed combustion of a mixture of castor oil - LPG on a circular tube burner. Percentage of LPG fuel in a mixture of jatropha curcas oil - LPG varied as much as 10%, 20%, 30%, and 40% of the mass flow jatropha curcas oil vapor. Considering the flame of fire there are two angles formed which describe burning velocity. Also there are formed two cones of fire where the bright blue inside cone is a premixed flame, while the outer blue white cone is flame a diffusion flame. An increase in the percentage of LPG makes the value of top and bottom angle increase. So that the burning velocity on the upper angle decrease whilst on bottom angle increase.

  2. Curved wall-jet burner for synthesizing titania and silica nanoparticles

    KAUST Repository

    Ismail, Mohamed

    2015-01-01

    A novel curved wall-jet (CWJ) burner was designed for flame synthesis, by injecting precursors through a center tube and by supplying fuel/air mixtures as an annular-inward jet for rapid mixing of the precursors in the reaction zone. Titanium dioxide (TiO2) and silicon dioxide (SiO2) nanoparticles were produced in ethylene (C2H4)/air premixed flames using titanium tetraisopropoxide (TTIP) and hexamethyldisiloxane (HMDSO) as the precursors, respectively. Particle image velocimetry measurements confirmed that the precursors can be injected into the flames without appreciably affecting flow structure. The nanoparticles were characterized using X-ray diffraction, Raman spectroscopy, the Brunauer-Emmett-Teller (BET) method, and high-resolution transmission electron microscopy. In the case of TiO2, the phase of nanoparticles could be controlled by adjusting the equivalence ratio, while the particle size was dependent on the precursor loading rate and the flame temperature. The synthesized TiO2 nanoparticles exhibited high crystallinity and the anatase phase was dominant at high equivalence ratios (φ > 1.3). In the case of SiO2, the particle size could be controlled from 11 to 18 nm by adjusting the precursor loading rate. © 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

  3. On the instability of a modified cup-burner flame in the infrared spectral region

    Directory of Open Access Journals (Sweden)

    Petr Bitala

    2016-03-01

    Full Text Available This study describes the modification of a standardised cup-burner apparatus. The replacement of the original glass chimney is performed by shielding a nitrogen co-flow enabled measurement at a wavelength of 3.9 μm. This modification, together with a special arrangement of the measuring system (spectral filtering, data acquisition and post-processing, permitted the observation of various types of hydrodynamic instabilities, including transition states. The advantages of our arrangement are demonstrated with an ethylene non-premixed flame with high sooting tendency. Two known modes of hydrodynamic instability (varicose and sinuous that occur in buoyant flames were studied and described quantitatively. Based on the intensity of the infrared emissions, we identified and qualitatively described the modes of periodic hydrodynamic instability that are accompanied by flame tip opening, which has not been observed for this type of flame.

  4. Performance analysis of cooling stabilizing burners for different stress boiler unit

    OpenAIRE

    Fialko, N. M.; Prokopov, V. H.; Alyosha, S. A.; Sherenkovskyy, Y.; Meranova, N. A.; Polozenko, N. P.; Malecki, A. E.

    2013-01-01

    The numerical research data of the jet–stabilization burners cooling system of with different baffles are presented of the jet airflow of inside end surface by flat and round jets with different width pylon is presented. The analysis of the load influence on the boiler efficiency cooling system is carried out. Наведено дані числових досліджень систем охолодження струменево- стабілізаторних пальникових пристроїв за схемою із струменевим обдувом внутрішньої торцевої ...

  5. Comparative Study of the Reactor Burner Efficiency for Transmutation of Minor Actinides

    Energy Technology Data Exchange (ETDEWEB)

    Gulevich, A.; Zemskov, E. [Institute of Physics and Power Engineering, Bondarenko sq. 1, Obninsk, Kaluga region, 249020 (Russian Federation); Degtyarev, A.; Kalugin, A.; Ponomarev, L. [Russian Research Center ' Kurchatov Institute' , Kurchatov sq. 1, Moscow, 123182 (Russian Federation); Konev, V.; Seliverstov, V. [Institute of Theoretical and Experimental Physics, ul. B. Cheremushinskaya 25, Moscow, 117259 (Russian Federation)

    2009-06-15

    Transmutation of minor actinides (MA) in the closed nuclear fuel cycle (NFC) is a one of the most important problem for future nuclear energetic. There are several approaches for MA transmutation but there are no common criteria for the comparison of their efficiency. In paper [1] we turned out the attention to the importance of taking into account the duration of the closed NFC in addition to a usual criterion of the neutron economy. In accordance with these criteria the transmutation efficiency are compared of two fast reactors (sodium and lead cooled) and three types of ADS-burners: LBE-cooled reactors (fast neutron spectrum), molten-salt reactor (intermediate spectrum) and heavy water reactor (thermal spectrum). It is shown that the time of transmutation of loaded MA in the closed nuclear fuel cycle is more than 50 years. References: A. Gulevich, A. Kalugin, L. Ponomarev, V. Seliverstov, M. Seregin, 'Comparative Study of ADS for Minor Actinides Transmutation', Progress in Nuclear Energy, 50, March-August, p. 358, 2008. (authors)

  6. Studi Eksperimen Distribusi Temperatur Nyala Api Kompor Bioetanol Tipe Side Burner dengan Variasi Diameter Firewall

    Directory of Open Access Journals (Sweden)

    R.R. Vienna Sona Saputri Soetadi

    2012-09-01

    Full Text Available Untuk mendapatkan kompor bioetanol efisiensi thermal maksimal diperlukan penelitian komprehensif. Salah satunya adalah penelitian terhadap posisi peletakkan beban pada kompor bioetanol kompak. Pengujian dilakukan pada kompor uji bioetanol dengan kadar 99%, yaitu kompor bioetanol tipe side burner dengan firewall 2.5 inci dan firewall 3 inci. Pengukuran temperatur api dengan 13 thermocouple K dengan pengukuran searah api keatas setiap 5 mm-an. Kemudian, water boiling test dilakukan untuk mendapatkan daya dan beban dan dilanjutkan mengukur waktu pendidihan air. Hasil penelitian ini menunjukkan gambaran total distribusi temperatur nyala api difusi. Hasil menunjukkan untuk kompor 2.5 inci dengan daya 1.6 kW mempunyai temperatur 542 ºC dengan jarak ketinggian 5 mm dari rim kompor sedangkan kompor 3 inci menghasilkan daya 2.38 kW dengan temperatur 516 ºC.

  7. Numerical simulations for the coal/oxidant distribution effects between two-stages for multi opposite burners (MOB) gasifier

    International Nuclear Information System (INIS)

    Unar, Imran Nazir; Wang, Lijun; Pathan, Abdul Ghani; Mahar, Rasool Bux; Li, Rundong; Uqaili, M. Aslam

    2014-01-01

    Highlights: • We simulated a double stage 3D entrained flow coal gasifier with multi-opposite burners. • The various reaction mechanisms have evaluated with experimental results. • The effects of coal and oxygen distribution between two stages on the performance of gasifier have investigated. • The local coal to oxygen ratio is affecting the overall efficiency of gasifier. - Abstract: A 3D CFD model for two-stage entrained flow dry feed coal gasifier with multi opposite burners (MOB) has been developed in this paper. At each stage two opposite nozzles are impinging whereas the two other opposite nozzles are slightly tangential. Various numerical simulations were carried out in standard CFD software to investigate the impacts of coal and oxidant distributions between the two stages of the gasifier. Chemical process was described by Finite Rate/Eddy Dissipation model. Heterogeneous and homogeneous reactions were defined using the published kinetic data and realizable k–ε turbulent model was used to solve the turbulence equations. Gas–solid interaction was defined by Euler–Lagrangian frame work. Different reaction mechanism were investigated first for the validation of the model from published experimental results. Then further investigations were made through the validated model for important parameters like species concentrations in syngas, char conversion, maximum inside temperature and syngas exit temperature. The analysis of the results from various simulated cases shows that coal/oxidant distribution between the stages has great influence on the overall performance of gasifier. The maximum char conversion was found 99.79% with coal 60% and oxygen 50% of upper level of injection. The minimum char conversion was observed 95.45% at 30% coal with 40% oxygen at same level. In general with oxygen and coal above or equal to 50% of total at upper injection level has shown an optimized performance

  8. Experimental and numerical study of the accuracy of flame-speed measurements for methane/air combustion in a slot burner

    Energy Technology Data Exchange (ETDEWEB)

    Selle, L.; Ferret, B. [Universite de Toulouse, INPT, UPS, IMFT, Institut de Mecanique des Fluides de Toulouse (France); CNRS, IMFT, Toulouse (France); Poinsot, T. [Universite de Toulouse, INPT, UPS, IMFT, Institut de Mecanique des Fluides de Toulouse (France); CNRS, IMFT, Toulouse (France); CERFACS, Toulouse (France)

    2011-01-15

    Measuring the velocities of premixed laminar flames with precision remains a controversial issue in the combustion community. This paper studies the accuracy of such measurements in two-dimensional slot burners and shows that while methane/air flame speeds can be measured with reasonable accuracy, the method may lack precision for other mixtures such as hydrogen/air. Curvature at the flame tip, strain on the flame sides and local quenching at the flame base can modify local flame speeds and require corrections which are studied using two-dimensional DNS. Numerical simulations also provide stretch, displacement and consumption flame speeds along the flame front. For methane/air flames, DNS show that the local stretch remains small so that the local consumption speed is very close to the unstretched premixed flame speed. The only correction needed to correctly predict flame speeds in this case is due to the finite aspect ratio of the slot used to inject the premixed gases which induces a flow acceleration in the measurement region (this correction can be evaluated from velocity measurement in the slot section or from an analytical solution). The method is applied to methane/air flames with and without water addition and results are compared to experimental data found in the literature. The paper then discusses the limitations of the slot-burner method to measure flame speeds for other mixtures and shows that it is not well adapted to mixtures with a Lewis number far from unity, such as hydrogen/air flames. (author)

  9. Experiments on the TECFLAM standard burner. Final colloquium; Experimente am TECFLAM Standard-Brenner. Abschlusskolloquium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    This year's annual seminar had two main subjects: First, the final colloquium of the CRAY-TECFLAM project in which an industrial code for simulation of combustion processes in furnaces and gas turbines was developed in cooperation with the relevant industry, and secondly, investigations on a TECFLAM standard burner which served to establish a reliable set of state variables by different methods that were applied simultaneously, as well as the validation of the mathematical models. [German] Das alljaehrliche oeffentliche Seminar stand in diesem Jahr unter zwei zentralen Themen: zum einen das Abschlusskolloquium des CRAY-TECFLAM-Projekts, in dem ein Industriecode zur Simulation der Verbrennungsvorgaenge in Feuerungen und Gasturbinen - unter Beteiligung der relevanten Industrie - entwickelt wurde, zum anderen die Untersuchungen am TECFLAM Standardbrenner, mit denen ein verlaesslicher Satz von Zustandsgroessen mit unterschiedlichen, aber simultan angewandten Messmethoden ermittelt wird und die mathematischen Modelle validiert werden. (orig.)

  10. Recurrent burner syndrome due to presumed cervical spine osteoblastoma in a collision sport athlete – a case report

    Directory of Open Access Journals (Sweden)

    Goins Maurice L

    2007-06-01

    Full Text Available Abstract We present a case of a 35-year-old active rugby player presenting with a history of recurrent burner syndrome thought secondary to an osteoblastoma involving the posterior arch of the atlas. Radiographically, the lesion had features typical for a large osteoid osteoma or osteoblastoma, including osseous expansion, peripheral sclerosis and bony hypertrophy, internal lucency, and even suggestion of a central nidus. The patient subsequently underwent an en bloc resection of the posterior atlas via a standard posterior approach. The surgery revealed very good clinical results. In this report, we will discuss in detail, the presentation, treatment, and return to play recommendations involving this patient.

  11. Metastatic and non-metastatic lymph nodes. Quantification and different distribution of iodine uptake assessed by dual-energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, Stefania [European Institute of Oncology, Department of Radiology, Milan (Italy); Radice, Davide [Department of Epidemiology and Biostatistics, Milan (Italy); Femia, Marco; Vigorito, Raffaella [Universita di Milano, Department of Health Sciences, Milan (Italy); De Marco, Paolo; Origgi, Daniela [Medical Physics, European Institute of Oncology, Milan (Italy); Preda, Lorenzo [Division of Radiology, National Centre of Oncological Hadrontherapy (CNAO Foundation), Pavia (Italy); University of Pavia, Department of Clinical, Surgical, Diagnostic and Paediatric Sciences, Pavia (Italy); Barberis, Massimo [European Institute of Oncology, Department of Pathology, Milan (Italy); Mauri, Giovanni [European Institute of Oncology, Division of Interventional Radiology, Milan (Italy); Mauro, Alberto [GE Medical Systems Italia SpA, Milan (Italy); Bellomi, Massimo [European Institute of Oncology, Department of Radiology, Milan (Italy); Universita di Milano, Department of Oncology, Milan (Italy)

    2018-02-15

    To evaluate quantification of iodine uptake in metastatic and non-metastatic lymph nodes (LNs) by dual-energy CT (DECT) and to assess if the distribution of iodine within LNs at DECT correlates with the pathological structure. Ninety LNs from 37 patients (23 with lung and 14 with gynaecological malignancies) were retrospectively selected. Information of LNs sent for statistical analysis included Hounsfield units (HU) at different energy levels; decomposition material densities fat-iodine, iodine-fat, iodine-water, water-iodine. Statistical analysis included evaluation of interobserver variability, material decomposition densities and spatial HU distribution within LNs. Interobserver agreement was excellent. There was a significant difference in iodine-fat and iodine-water decompositions comparing metastatic and non-metastatic LNs (p < 0.001); fat-iodine and water-iodine did not show significant differences. HU distribution showed a significant gradient from centre to periphery within non-metastatic LNs that was significant up to 20-30% from the centre, whereas metastatic LNs showed a more homogeneous distribution of HU, with no significant gradient. DECT demonstrated a lower iodine uptake in metastatic compared to non-metastatic LNs. Moreover, the internal iodine distribution showed an evident gradient of iodine distribution from centre to periphery in non-metastatic LNs, and a more homogeneous distribution within metastatic LNs, which corresponded to the pathological structure. (orig.)

  12. Environmental control implications of generating electric power from coal. 1977 technology status report. Appendix D. Assessment of NO/sub x/ control technology for coal fired utility boilers. [Low-excess-air, staged combustion, flu gas recirculation and burner design

    Energy Technology Data Exchange (ETDEWEB)

    1977-12-01

    An NOx control technology assessment study was conducted to examine the effectiveness of low-excess-air firing, staged combustion, flue gas recirculation, and current burner/boiler designs as applied to coal-fired utility boilers. Significant variations in NOx emissions exist with boiler type, firing method, and coal type, but a relative comparison of emissions control performance, cost, and operational considerations is presented for each method. The study emphasized the numerous operational factors that are of major importance to the user in selecting and implementing a combustion modification technique. Staged combustion and low-excess-air operation were identified as the most cost-effective methods for existing units. Close control of local air/fuel ratios and rigorous combustion equipment maintenance are essential to the success of both methods. Flue gas recirculation is relatively ineffective and has the added concern of tube erosion. More research is needed to resolve potential corrosion concerns with low-NOx operating modes. Low-NOx burners in conjunction with a compartmentalized windbox are capable of meeting a 0.6-lb/million Btu emission level on new units. Advanced burner designs are being developed to meet research emission goals of approximately 0.25 lb/MBtu.

  13. Pollutant exposures from unvented gas cooking burners: A Simulation-based Assessment for Southern California

    Energy Technology Data Exchange (ETDEWEB)

    Logue, Jennifer M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Indoor Environment Group and Residential Building Systems Group; Klepeis, Neil E. [Stanford Univ., CA (United States). Dept. of Civil and Environmental Engineering; San Diego Univ., CA (United States). Center for Behavioral Epidemiology and Community Health; Lobscheid, Agnes B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Indoor Environment Group; Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Indoor Environment Group and Residential Building Systems Group

    2014-01-01

    Residential natural gas cooking burners (NGCBs) can emit substantial quantities of pollutants, and they are typically used without venting range hoods. In this study, LBNL researchers quantified pollutant concentrations and occupant exposures resulting from NGCB use in California homes.The simulation model estimated that—in homes using NGCBs without coincident use of venting range hoods -- 62%, 9%, and 53% of occupants are routinely exposed to NO2, CO, and HCHO levels that exceed acute health-based standards and guidelines. NGCB use increased the sample median of the highest simulated 1-hr indoor concentrations by 100, 3,000, and 20 ppb for NO2, CO, and HCHO, respectively. The study recommends that reducing pollutant exposures from NGCBs should be a public health priority. Simulation results suggest that regular use of even moderately effective venting range hoods would dramatically reduce the percentage of homes in which concentrations exceed health-based standards.

  14. Burner redesign for the reduction of the unburned particulate emission in thermal power stations of Comision Federal de Electricidad; Rediseno de quemadores para la reduccion de la emision de particulas inquemadas en centrales termicas de la Comisionon Federal de Electricidad

    Energy Technology Data Exchange (ETDEWEB)

    Huerta Espino, Mario; Espipnoza Garza, Jesus; Mani Gonzalez, Alejandro; Giles Alarcon, Armando; Pena Garcia, Adriana; Albarran Sanchez, Irma L; Mendez Aranda, Angel [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2001-07-01

    In the presence of the increasing demand for reaching higher efficiencies and a smaller production of polluting emissions in combustion systems, studies focused to the optimization of the present designs of burners are required. The Comision Federal de Electricidad (CFE) and the Instituto de Investigaciones Electricas (IIE) have established a project that contemplates the redesign of burners in ten of its units of thermoelectric generation. In this work the redesign of the flame stabilizer or diffuser for the reduction of the unburned particulate emission is explained. The results of the modeling of a burner of rotational flow of steam generators of the CFE are shown, as well as the graphs of the contours of the recirculation zone generated by each diffuser without combustion and a figure of the velocity profile that is generated in front of the diffuser. In agreement with the results obtained in the aerodynamic evaluation of frontal burners of rotational flow, it is possible to established that the characteristics of the recirculation zone, generated by this type of burners, are related to geometric parameters of the diffuser that identify with the number of turns and the pressure drop, where it is necessary to look for designs that improve the conditions of the mixing process and combustion in the burner. [Spanish] Ante la creciente demanda por alcanzar mayores eficiencias y una menor produccion de emisiones contaminantes en sistemas de combustion, se requieren estudios enfocados a la optimizacion de los disenos actuales de quemadores. La Comision Federal de Electricidad (CFE) y el Instituto de Investigaciones Electricas (IIE) han establecido un proyecto que contempla el rediseno de quemadores en diez de sus unidades de generacion termoelectrica. En este trabajo se explica el rediseno del estabilizador de flama o difusor para la reduccion de la emision de particulas inquemadas. Se muestran los resultados de la modelacion de un quemador de flujo rotacional de

  15. Transient change in the shape of premixed burner flame with the superposition of pulsed dielectric barrier discharge

    Science.gov (United States)

    Zaima, Kazunori; Sasaki, Koichi

    2016-08-01

    We investigated the transient phenomena in a premixed burner flame with the superposition of a pulsed dielectric barrier discharge (DBD). The length of the flame was shortened by the superposition of DBD, indicating the activation of combustion chemical reactions with the help of the plasma. In addition, we observed the modulation of the top position of the unburned gas region and the formations of local minimums in the axial distribution of the optical emission intensity of OH. These experimental results reveal the oscillation of the rates of combustion chemical reactions as a response to the activation by pulsed DBD. The cycle of the oscillation was 0.18-0.2 ms, which could be understood as the eigenfrequency of the plasma-assisted combustion reaction system.

  16. EVALUATION OF INTERNALLY STAGED COAL BURNERS AND SORBENT JET AERODYNAMICS FOR COMBINED SO2/NOX CONTROL IN UTILITY BOILERS, VOLUME 1, TESTING IN A 10 MILLION BTU/HR EXPERIMENTAL FURNACE

    Science.gov (United States)

    The document gives results of tests conducted in a 2 MWt experimental furnace to: (1) investigate ways to reduce NOx emissions from utility coal burners without external air ports (i.e., with internal fuel/air staging); and (2) improve the performance of calcium-based sorbents fo...

  17. Pulsed fan burner units with integrated automatic lambda control. Pt. 2; Impulsgeblaesebrennaggregate mit integrierter LAMBDA-Automatik. T. 2

    Energy Technology Data Exchange (ETDEWEB)

    Kiem, Ralph

    2010-02-15

    In recent years, pulsed firing technology has gained increasing importance in the ceramic industry for optimizing firing quality while saving energy through the use of PLC technology. To satisfy ever more stringent environmental regulations, including the German Technical Instructions on Air Quality Control (TA Luft) and the Federal Immission Control Act (Blmschg), the further improvement of proven systems currently in use is absolutely essential. Pulsed fan burners with automatic combustion-air adjustment are the development engineers' response to the need for flexibly automated turbulences in the combustion atmosphere that comply with statutory emission standards. In addition, energy savings of some 20% can be achieved with this technology compared to the older pulsed combustion systems. (orig.)

  18. Prognostic Significance of the Number of Positive Lymph Nodes in Women With T1-2N1 Breast Cancer Treated With Mastectomy: Should Patients With 1, 2, and 3 Positive Lymph Nodes Be Grouped Together?

    Energy Technology Data Exchange (ETDEWEB)

    Dai Kubicky, Charlotte, E-mail: charlottedai@gmail.com [Department of Radiation Medicine and Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon (United States); Mongoue-Tchokote, Solange [Biostatistics Shared Resource, Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon (United States)

    2013-04-01

    Purpose: To determine whether patients with 1, 2, or 3 positive lymph nodes (LNs) have similar survival outcomes. Methods and Materials: We analyzed the Surveillance, Epidemiology, and End Results registry of breast cancer patients diagnosed between 1990 and 2003. We identified 10,415 women with T1-2N1M0 breast cancer who were treated with mastectomy with no adjuvant radiation, with at least 10 LNs examined and 6 months of follow-up. The Kaplan-Meier method and log–rank test were used for survival analysis. Multivariate analysis was performed using the Cox proportional hazard model. Results: Median follow-up was 92 months. Ten-year overall survival (OS) and cause-specific survival (CSS) were progressively worse with increasing number of positive LNs. Survival rates were 70%, 64%, and 60% (OS), and 82%, 76%, and 72% (CSS) for 1, 2, and 3 positive LNs, respectively. Pairwise log–rank test P values were <.001 (1 vs 2 positive LNs), <.001 (1 vs 3 positive LNs), and .002 (2 vs 3 positive LNs). Multivariate analysis showed that number of positive LNs was a significant predictor of OS and CSS. Hazard ratios increased with the number of positive LNs. In addition, age, primary tumor size, grade, estrogen receptor and progesterone receptor status, race, and year of diagnosis were significant prognostic factors. Conclusions: Our study suggests that patients with 1, 2, and 3 positive LNs have distinct survival outcomes, with increasing number of positive LNs associated with worse OS and CSS. The conventional grouping of 1-3 positive LNs needs to be reconsidered.

  19. Burner Rig Hot Corrosion of a Single Crystal Ni-48Al-Ti-Hf-Ga Alloy

    Science.gov (United States)

    Nesbitt, James A.; Darolia, Ram; Cuy, Michael D.

    1998-01-01

    The hot corrosion resistance of a single crystal Ni-48Al-1Ti-0.5Hf-0.2Ga alloy was examined in a Mach 0.3 burner rig at 900 C for 300 hours. The combustion chamber was doped with 2 ppmw synthetic sea salt. The hot corrosion attack produced a random mound morphology on the surface. Microstructurally, the hot corrosion attack appeared to initiate with oxide-filled pits which were often broad and shallow. At an intermediate stage, the pits increased in size to incorporate unoxidized Ni islands in the corrosion product. The rampant attack stage, which was observed only at sharp sample corners, was characterized by rapid inward growth of alumina in finger-like protrusions incorporating significant amounts of Al-depleted Ni islands. Aluminum consumption in the oxide fingers resulted in the growth of a gamma' layer ahead of the advancing oxide fingers.

  20. Burner rig hot corrosion of a single crystal Ni-48Al-Ti-Hf-Ga alloy

    Energy Technology Data Exchange (ETDEWEB)

    Nesbitt, J.A.; Darolia, R.; Cuy, M.D.

    1999-07-01

    The hot corrosion resistance of a single crystal Ni-48Al-1Ti-0.5Hf-0.2Ga alloy was examined in a Mach 0.3 burner rig at 900 C for 300 hours. The combustion chamber was doped with 2 ppmw synthetic sea salt. The hot corrosion attack produced a random mound morphology on the surface. Microstructurally, the hot corrosion attack appeared to initiate with oxide-filled pits which were often broad and shallow. At an intermediate stage, the pits increased in size to incorporate unoxidized Ni islands in the corrosion product. The rampant attack stage, which was observed only at sharp sample corners, was characterized by rapid inward growth of alumina in finger-like protrusions incorporating significant amounts of Al-depleted Ni islands. Aluminum consumption in the oxide fingers resulted in the growth of a {gamma}{prime} layer ahead of the advancing oxide fingers.

  1. Stabilization and structure of N-heptane flame on CWJ-spray burner with kHZ SPIV and OH-PLIF

    KAUST Repository

    Mansour, Morkous S.

    2015-08-31

    A curved wall-jet (CWJ) burner was employed to stabilize turbulent spray flames that utilized a Coanda effect by supplying air as annular-inward jet over a curved surface, surrounding an axisymmetric solid cone fuel spray. The stabilization characteristics and structure of n-heptane/air turbulent flames were investigated with varying fuel and air flow rates and the position of pressure atomizer (L). High-speed planar laser-induced fluorescence (PLIF) of OH radicals delineated reaction zone contours and simultaneously stereoscopic particle image velocimetry (SPIV) quantified the flow field features, involving turbulent mixing within spray, ambient air entrainment and flame-turbulence interaction. High turbulent rms velocities were generated within the recirculation zone, which improved the flame stabilization. OH fluorescence signals revealed a double flame structure near the stabilization edge of lifted flame that consisted of inner partially premixed flame and outer diffusion flame front. The inner reaction zone is highly wrinkled and folded due to significant turbulent mixing between the annular-air jet and the fuel vapor generated from droplets along the contact interface of this air jet with the fuel spray. Larger droplets, having higher momentum are able to penetrate the inner reaction zone and then vaporized in the low-speed hot region bounded by these reaction zones; this supports the outer diffusion flame. Frequent local extinctions in the inner reaction zone were observed at low air flow rate. As flow rate increases, the inner zone is more resistant to local extinction despite of its high wrinkling and corrugation degree. However, the outer reaction zone exhibits stable and mildly wrinkled features irrespective of air flow rate. The liftoff height increases with the air mass flow rate but decreases with L.

  2. Willingness-to-Pay for Lipid-Based Nutrient Supplements in Burkina Faso

    International Nuclear Information System (INIS)

    Guissou, Rosemonde; Adams, Katherine; Xu Yingying; Vosti, Stephen; Hess, Sonja; Ouedraogo, Jean Bosco

    2014-01-01

    Full text: Supplementing young children’s diets with small-quantity lipid-based nutrient supplements (SQ-LNS) is a promising strategy to prevent growth restriction and improve development. It is uncertain how best to scale up the distribution of SQ-LNS and both private and public approaches are being considered. This paper reports on the willingness-to-pay (WTP) by households in rural Burkina Faso for SQ-LNS designed to prevent childhood undernutrition. In a recent randomized controlled nutrition efficacy trial in the Dandé Health District in rural Burkina Faso, 20 g of SQ-LNS per day along with selected health care services have been shown to increase the linear growth and weight gain of children who received the supplement daily from 9-18 months of age. Given the frequency and duration of prescribed consumption of SQ-LNS (one sachet per day, per child) and inter-household differences in poverty, a hybrid distribution system that reaches target consumers through both public channels and retail markets may be recommended; the viability of the latter will hinge on demand. Therefore, policy makers will need to consider household-level demand for SQ-LNS and the factors that influence demand to guide decisions regarding the cost burden borne by recipients versus public sector programs. Using a contingent valuation approach, we solicited, at baseline and six months later, the hypothetical WTP for a daily dose of 20 g of SQ-LNS and a traditional substitute, herbal teas, from a subsample (N = 319) of households participating in the efficacy trial. WTP for SQ-LNS is positive for almost all households, but WTP for SQ-LNS is, on average, lower than WTP for herbal teas. At baseline, average WTP for a day’s supply of SQ-LNS is $0.22 (4th quarter 2011 USD), while average WTP for herbal teas is $0.28. Approximately six months later, average WTP for LNS and for herbal teas, respectively, are $0.21 and $0.25. These results suggest that while households do value SQ-LNS

  3. Development of a hardware-in-the-loop-test rig to verify the reliability of oil burner pumps. Application by the use of biocide in domestic heating oil; Entwicklung eines Hardware-in-the-loop Pruefstands zum Nachweis der Betriebssicherheit von Oelbrennerpumpen. Anwendungen bei Einsatz von Biozidadditiven

    Energy Technology Data Exchange (ETDEWEB)

    Rheinberg, Oliver van; Lukito, Jayadi; Liska, Martin [Oel-Waerme-Institut gGmbH (OWI), Aachen-Herzogenrath (Germany)

    2009-09-15

    Within this project, a hardware-in-the-loop test rig has been developed to investigate the influence of different fuels on the reliability of oil burner pumps. The test rig is constructed with commercial burner components. One test rig consists of four pump cycles, where the fuel recirculates for max. 2000 h. Low powered electric motors of 90 Watts have been used deliberately, so that the apparatus is more sensitive to failure due to an increase in pump load. A practise relevant intermittent operating mode has been implemented for the simulation of real operation characteristics. The measured variable and evaluation parameters are start-up torque, intake pressure, fuel pump pressure and temperature. Operation failures of oil burner pumps in the field, due to an over-additisation of biocides, have been observed. These failures could be reproducibly simulated on the pump test stands. The results of the project are a redefinition of limits of biocide concentration and the development of new biocides, which are suitable for use in domestic heating oil with a content of up to 20 % Fatty-Acid-Methyl-Ester. (orig.)

  4. Altitude Performance Characteristics of Turbojet-engine Tail-pipe Burner with Variable-area Exhaust Nozzle Using Several Fuel Systems and Flame Holders

    Science.gov (United States)

    Johnson, Lavern A; Meyer, Carl L

    1950-01-01

    A tail-pipe burner with a variable-area exhaust nozzle was investigated. From five configurations a fuel-distribution system and a flame holder were selected. The best configuration was investigated over a range of altitudes and flight Mach numbers. For the best configuration, an increase in altitude lowered the augmented thrust ratio, exhaust-gas total temperature, and tail-pipe combustion efficiency, and raised the specific fuel consumption. An increase in flight Mach number raised the augmented thrust ratio but had no apparent effect on exhaust-gas total temperature, tail-pipe combustion efficiency, or specific fuel consumption.

  5. Evaluation of partially premixed turbulent flame stability from mixture fraction statistics in a slot burner

    KAUST Repository

    Kruse, Stephan

    2018-04-11

    Partially premixed combustion is characterized by mixture fraction inhomogeneity upstream of the reaction zone and occurs in many applied combustion systems. The temporal and spatial fluctuations of the mixture fraction have tremendous impact on the combustion characteristics, emission formation, and flame stability. In this study, turbulent partially premixed flames are experimentally studied in a slot burner configuration. The local temperature and gas composition is determined by means of one-dimensional, simultaneous detection of Rayleigh and Raman scattering. The statistics of the mixture fraction are utilized to characterize the impact of the Reynolds number, the global equivalence ratio, the progress of mixing within the flame, as well as the mixing length on the mixing field. Furthermore, these effects are evaluated by means of a regime diagram for partially premixed flames. In this study, it is shown that the increase of the mixing length results in a significantly more stable flame. The impact of the Reynolds number on flame stability is found to be minor.

  6. Evaluation of partially premixed turbulent flame stability from mixture fraction statistics in a slot burner

    KAUST Repository

    Kruse, Stephan; Mansour, Mohy S.; Elbaz, Ayman M.; Varea, Emilien; Grü nefeld, Gerd; Beeckmann, Joachim; Pitsch, Heinz

    2018-01-01

    Partially premixed combustion is characterized by mixture fraction inhomogeneity upstream of the reaction zone and occurs in many applied combustion systems. The temporal and spatial fluctuations of the mixture fraction have tremendous impact on the combustion characteristics, emission formation, and flame stability. In this study, turbulent partially premixed flames are experimentally studied in a slot burner configuration. The local temperature and gas composition is determined by means of one-dimensional, simultaneous detection of Rayleigh and Raman scattering. The statistics of the mixture fraction are utilized to characterize the impact of the Reynolds number, the global equivalence ratio, the progress of mixing within the flame, as well as the mixing length on the mixing field. Furthermore, these effects are evaluated by means of a regime diagram for partially premixed flames. In this study, it is shown that the increase of the mixing length results in a significantly more stable flame. The impact of the Reynolds number on flame stability is found to be minor.

  7. Oxy-Combustion Burner and Integrated Pollutant Removal Research and Development Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Mark Schoenfield; Manny Menendez; Thomas Ochs; Rigel Woodside; Danylo Oryshchyn

    2012-09-30

    A high flame temperature oxy-combustion test facility consisting of a 5 MWe equivalent test boiler facility and 20 KWe equivalent IPR® was constructed at the Hammond, Indiana manufacturing site. The test facility was operated natural gas and coal fuels and parametric studies were performed to determine the optimal performance conditions and generated the necessary technical data required to demonstrate the technologies are viable for technical and economic scale-up. Flame temperatures between 4930-6120F were achieved with high flame temperature oxy-natural gas combustion depending on whether additional recirculated flue gases are added to balance the heat transfer. For high flame temperature oxy-coal combustion, flame temperatures in excess of 4500F were achieved and demonstrated to be consistent with computational fluid dynamic modeling of the burner system. The project demonstrated feasibility and effectiveness of the Jupiter Oxygen high flame temperature oxy-combustion process with Integrated Pollutant Removal process for CCS and CCUS. With these technologies total parasitic power requirements for both oxygen production and carbon capture currently are in the range of 20% of the gross power output. The Jupiter Oxygen high flame temperature oxy-combustion process has been demonstrated at a Technology Readiness Level of 6 and is ready for commencement of a demonstration project.

  8. Blow-off characteristics of turbulent premixed flames in curved-wall Jet Burner

    KAUST Repository

    Mansour, Morkous S.

    2015-08-02

    This study concerns the flame dynamics of a curved-wall jet (CWJ) stabilized turbulent premixed flame as it approaches blow-off conditions. Time resolved OH planar laser-induced fluorescence (PLIF) delineated reaction zone contours and simultaneously stereoscopic particle image velocimetry (SPIV) quantified the turbulent flow field features. Ethylene/air flames were stabilized in CWJ burner to determine the sequence of events leading to blowoff. For stably burning flames far from blowoff, flames are characterized with a recirculation zone (RZ) upstream for flame stabilization followed by an intense turbulent interaction jet (IJ) and merged-jet regions downstream; the flame front counterparts the shear layer vortices. Near blowoff, as the velocity of reactants increases, high local stretch rates exceed the extinction stretch rates instantaneously resulting in localized flame extinction along the IJ region. As Reynolds number (Re) increases, flames become shorter and are entrained by larger amounts of cold reactants. The increased strain rates together with heat loss effects result in further fragmentation of the flame, eventually leading to the complete quenching of the flame. This is explained in terms of local turbulent Karlovitz stretch factor (K) and principal flow strain rates associated with C contours. Hydrogen addition and increasing the RZ size lessen the tendency of flames to be locally extinguished.

  9. Flame emission spectroscopy measurement of a steam blast and air blast burner

    Directory of Open Access Journals (Sweden)

    Jozsa Viktor

    2017-01-01

    Full Text Available Control and online monitoring of combustion have become critical to meet the increasingly strict pollutant emission standards. For such a purpose, optical sensing methods, like flame emission spectrometry, seem to be the most feasible technique. Spectrometry is capable to provide information about the local equivalence ratio inside the flame through the chemiluminescence intensity ratio measurement of various radicals. In the present study, a 15 kW atmospheric burner was analyzed utilizing standard diesel fuel. Its plain jet type atomizer was operated with both air and steam atomizing mediums. Up to now, injection of steam into the reaction zone has attracted less scientific attention contrary to its practical importance. Spatial plots of OH*, CH*, and C2* excited radicals were analyzed at 0.35, 0.7, and 1 bar atomization gauge pressures, utilizing both atomizing mediums. The C2* was found to decrease strongly with increasing steam addition. The OH*/CH* and OH*/C2* chemiluminescence intensity ratios along the axis showed a divergent behavior in all the analyzed cases. Nevertheless, CH*/C2* chemiluminescence intensity ratio decreased only slightly, showing low sensitivity to the position of the spectrometer. The findings may be directly applied in steady operating combustion systems, i. e., gas turbines, boilers, and furnaces.

  10. Core Power Limits For A Lead-Bismuth Natural Circulation Actinide Burner Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Cliff Bybee; Kim, D.; Todreas, N. E.; Mujid S. Kazimi

    2002-04-01

    The Idaho National Engineering and Environmental Laboratory and Massachusetts Institute of Technology are investigating the suitability of lead-bismuth cooled fast reactors for producing low-cost electricity as well as for actinide burning. The design being considered here is a pool type reactor that burns actinides and utilizes natural circulation of the primary coolant, a conventional steam power conversion cycle, and a passive decay heat removal system. Thermal-hydraulic evaluations of the actinide burner reactor were performed to determine allowable core power ratings that maintain cladding temperatures below corrosion-established temperature limits during normal operation and following a loss-of-feedwater transient. An economic evaluation was performed to optimize various design parameters by minimizing capital cost. The transient power limit was initially much more restrictive than the steady-state limit. However, enhancements to the reactor vessel auxiliary cooling system for transient decay heat removal resulted in an increased power limit of 1040 MWt, which was close to the steady-state limit. An economic evaluation was performed to estimate the capital cost of the reactor and its sensitivity to the transient power limit. For the 1040 MWt power level, the capital cost estimate was 49 mills per kWhe based on 1999 dollars.

  11. Emissions of Monoxide of Carbon and Methane in an atmospheric burner of natural gas

    International Nuclear Information System (INIS)

    Amell A, A.A.; Gil B, E.; Cadavid S, F.J.

    1999-01-01

    In Colombia, the development of gas equipment industry has been characterized by a copy of foreign systems, without going further on the basic principles of operation and design of gas appliances. In order to guarantee an efficient and safe use of this energetic during the present plan of massive use of gas in the country, is necessary to know and dominate all the main phenomena influencing the design and operation of gas appliances, among them is the rate of primary aeration. In this study we analyze the production of CO and CH4 emissions in a premixed atmospheric burner when we modify pressure supply, tip size, injector size, mixer length and diameter of the throat. Results show that mixer geometry has a great influence on CO and CH4 emissions. When aeration rate was less or equal than 0.5 for power greater than 2.3 kw, CO emissions were beyond critic boundary. In the other hand, when we increased gas pressure supply, we observed those CH4 emissions decreased

  12. Large Eddy Simulation Analysis on Confined Swirling Flows in a Gas Turbine Swirl Burner

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2017-12-01

    Full Text Available This paper describes a Large Eddy Simulation (LES investigation into flow fields in a model gas turbine combustor equipped with a swirl burner. A probability density function was used to describe the interaction physics of chemical reaction and turbulent flow as liquid fuel was directly injected into the combustion chamber and rapidly mixed with the swirling air. Simulation results showed that heat release during combustion accelerated the axial velocity motion and made the recirculation zone more compact. As the combustion was taking place under lean burn conditions, NO emissions was less than 10 ppm. Finally, the effects of outlet contraction on swirling flows and combustion instability were investigated. Results suggest that contracted outlet can enhance the generation of a Central Vortex Core (CVC flow structure. As peak RMS of velocity fluctuation profiles at center-line suggested the turbulent instability can be enhanced by CVC motion, the Power Spectrum Density (PSD amplitude also explained that the oscillation at CVC position was greater than other places. Both evidences demonstrated that outlet contraction can increase the instability of the central field.

  13. Analysis of directional radiative behavior and heating efficiency for a gas-fired radiant burner

    International Nuclear Information System (INIS)

    Li, B.X.; Lu, Y.P.; Liu, L.H.; Kudo, K.; Tan, H.P.

    2005-01-01

    For the purpose of energy conservation and uniform heating of object surface, a gas-fired porous radiant burner with a bundle of reflecting tubes is developed. A physical model is developed to simulate the directional radiative behavior of this heating device, in which the Monte Carlo method based on the concept of radiation distribution factor is used to compute the directional radiative behavior. The effects of relating parameters on the directional behavior of radiative heating and the heating efficiency are analyzed. With the increase of the length-to-radius ratio of tube, the radiation heating efficiency decreases, but the radiation energy incident on the object surface is more collimated. The radiation heating efficiency increases with the specular reflectivity. With the increase in length of tube segment with specular reflective surface, the radiation heating efficiency increases, but the extent of concentration and collimation of radiative energy decreases. For real design of the heating device, some trade-offs are needed to balance the radiation heating efficiency and the uniformity of radiative heating of object surface

  14. The Structure of Neurexin 1[alpha] Reveals Features Promoting a Role as Synaptic Organizer

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Fang; Venugopal, Vandavasi; Murray, Beverly; Rudenko, Gabby (Michigan)

    2014-10-02

    {alpha}-Neurexins are essential synaptic adhesion molecules implicated in autism spectrum disorder and schizophrenia. The {alpha}-neurexin extracellular domain consists of six LNS domains interspersed by three EGF-like repeats and interacts with many different proteins in the synaptic cleft. To understand how {alpha}-neurexins might function as synaptic organizers, we solved the structure of the neurexin 1{alpha} extracellular domain (n1{alpha}) to 2.65 {angstrom}. The L-shaped molecule can be divided into a flexible repeat I (LNS1-EGF-A-LNS2), a rigid horseshoe-shaped repeat II (LNS3-EGF-B-LNS4) with structural similarity to so-called reelin repeats, and an extended repeat III (LNS5-EGF-B-LNS6) with controlled flexibility. A 2.95 {angstrom} structure of n1{alpha} carrying splice insert SS3 in LNS4 reveals that SS3 protrudes as a loop and does not alter the rigid arrangement of repeat II. The global architecture imposed by conserved structural features enables {alpha}-neurexins to recruit and organize proteins in distinct and variable ways, influenced by splicing, thereby promoting synaptic function.

  15. Enhanced oral bioavailability of docetaxel by lecithin nanoparticles: preparation, in vitro, and in vivo evaluation

    Science.gov (United States)

    Hu, Kaili; Cao, Shan; Hu, Fuqiang; Feng, Jianfang

    2012-01-01

    The aim of this research work was to investigate the potential of lecithin nanoparticles (LNs) in improving the oral bioavailability of docetaxel. Docetaxel-loaded LNs (DTX-LNs) were prepared from oil-in-water emulsions and characterized in terms of morphology, size, zeta potential, and encapsulation efficiency. The in vitro release of docetaxel from the nanoparticles was studied by using dialysis bag method. Caco-2 cell monolayer was used for the in vitro permeation study of DTX-LNs. Bioavailability studies were conducted in rats and different pharmacokinetic parameters were evaluated after oral administration of DTX-LNs. The results showed that DTX-LNs had a mean diameter of 360 ± 8 nm and exhibited spherical shape with smooth surface under transmission electron microscopy. The DTX-LNs showed a sustained-release profile, with about 80% of docetaxel released within 72 hours. The apical to basolateral transport of docetaxel across the Caco-2 cell monolayer from the DTX-LNs was 2.14 times compared to that of the docetaxel solution (0.15 × 10−5 ± 0.016 × 10−5 cm/second versus 0.07 × 10−5 ± 0.003 × 10−5 cm/second). The oral bioavailability of the DTX-LNs was 3.65 times that of docetaxel solution (8.75% versus 2.40%). These results indicate that DTX-LNs were valuable as an oral drug delivery system to enhance the absorption of docetaxel. PMID:22848177

  16. Increase in the efficiency of electric melting of pellets in an arc furnace with allowance for the energy effect of afterburning of carbon oxide in slag using fuel-oxygen burners

    Science.gov (United States)

    Stepanov, V. A.; Krakht, L. N.; Merker, E. E.; Sazonov, A. V.; Chermenev, E. A.

    2015-12-01

    The problems of increasing the efficiency of electric steelmaking using fuel-oxygen burners to supply oxygen for the afterburning of effluent gases in an arc furnace are considered. The application of a new energy-saving regime based on a proposed technology of electric melting is shown to intensify the processes of slag formation, heating, and metal decarburization.

  17. FY 1999 report on feasibility study of introduction of regenerative burner type furnaces into Shougang Corporation and Anshan Iron and Steel Group Company in China

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This fiscal 1999 survey is to link to COP3 (Third Session of the Conference of the Parties to the United Nations Framework Convention on Climate Change)joint implementations in the future. The regenerative burner type furnace is a new technology which is the fruit of one of Japan's national projects developed and put to practical use in the period fiscal 1993-1999. It reduces energy consumption and NOx emissions. The technology is separately applied to steel rollers at Shougang and Qinhungdao and to a new steel roller at Anshan. Their annual yields will be 550-thousand, 450-thousand, and 800-thousand tons, respectively. The amounts of annually conserved energy will be 159,500, 54,000, and 40,000 times 10{sup 6}kcal, respectively. Annual CO2 reduction rates are indicated to be 51, 26, 15%, and NOx reduction rates to be 82, 75, 74%. The amounts of initial investment are expected to be 800-million yen (furnace refurbishment), 250-million yen (burner improvement), and 150-million yen (additional construction of a new furnace). Investment recovery periods are calculated to be 3.3, 2.0, and 2.8 years. ROIs (returns on investment) are calculated to be 34, 54, and 40%. The project is economically feasible, with high profitability available at the present stage and in the future (with some problems to solve at Anshan). (NEDO)

  18. The motion of discs and spherical fuel particles in combustion burners based on Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Granada, E.; Patino, D.; Porteiro, J.; Collazo, J.; Miguez, J.L.; Moran, J. [University of Vigo, E.T.S. Ingenieros Industriales, Lagoas-Marcosende s/n, 36200-Vigo (Spain)

    2010-04-15

    The position of pellet fuel particles in a burner largely determines their combustion behaviour. This paper addresses the simulated motion of circles and spheres, equivalent to pellet, and their final position in a packed bed subject to a gravitational field confined inside rigid cylindrical walls. A simplified Monte Carlo statistical technique has been described and applied with the standard Metropolis method for the simulation of movement. This simplification provides an easier understanding of the method when applied to solid fuels in granular form, provided that they are only under gravitational forces. Not only have we contrasted one parameter, as other authors, but three, which are radial, bulk and local porosities, via Voronoi tessellation. Our simulations reveal a structural order near the walls, which declines towards the centre of the container, and no pattern was found in local porosity via Voronoi. Results with this simplified method are in agreement with more complex previously published studies. (author)

  19. Co-firing straw with coal in a swirl-stabilized dual-feed burner: modelling and experimental validation

    DEFF Research Database (Denmark)

    Yin, Chungen; Kær, Søren Knudsen; Rosendahl, Lasse

    2010-01-01

    This paper presents a comprehensive computational fluid dynamics (CFD) modelling study of co-firing wheat straw with coal in a 150 kW swirl-stabilized dual-feed burner flow reactor, in which the pulverized straw particles (mean diameter of 451μm) and coal particles (mean diameter of 110.4μm...... conversion. It is found that for pulverized biomass particles of a few hundred microns in diameter the intra-particle heat and mass transfer is a secondary issue at most in their conversion, and the global four-step mechanism of Jones and Lindstedt may be better used in modelling volatiles combustion......-lean core zone; whilst the coal particles are significantly affected by secondary air jet and swirled into the oxygen-rich outer radius with increased residence time (in average, 8.1s for coal particles vs. 5.2s for straw particles in the 3m high reactor). Therefore, a remarkable difference in the overall...

  20. The motion of discs and spherical fuel particles in combustion burners based on Monte Carlo simulation

    International Nuclear Information System (INIS)

    Granada, E.; Patino, D.; Porteiro, J.; Collazo, J.; Miguez, J.L.; Moran, J.

    2010-01-01

    The position of pellet fuel particles in a burner largely determines their combustion behaviour. This paper addresses the simulated motion of circles and spheres, equivalent to pellet, and their final position in a packed bed subject to a gravitational field confined inside rigid cylindrical walls. A simplified Monte Carlo statistical technique has been described and applied with the standard Metropolis method for the simulation of movement. This simplification provides an easier understanding of the method when applied to solid fuels in granular form, provided that they are only under gravitational forces. Not only have we contrasted one parameter, as other authors, but three, which are radial, bulk and local porosities, via Voronoi tessellation. Our simulations reveal a structural order near the walls, which declines towards the centre of the container, and no pattern was found in local porosity via Voronoi. Results with this simplified method are in agreement with more complex previously published studies.

  1. Chemical and biological characterization of residential oil burner emission. A literature survey

    International Nuclear Information System (INIS)

    Westerholm, R.; Peterson, A.

    1994-02-01

    This literature study covers the time period 1980 to 1993 and is concerned with oil burners used for residential heating with a nominal heating power of less than 20 kW, which are normally used in one-family houses. Emission samples from domestic heaters using organic fuels consists of a very complex matrix of pollutants ranging from aggregate states solid to gaseous. Biological effects elicited by exhaust emissions have been detected and determined. It has been shown for diesel vehicles that selection of fuel properties has an impact on combustion reaction paths which results in different exhaust chemical compositions. It was also determined that diesel fuel properties have an impact on the biological activity of diesel exhaust emissions, which is to be expected from their chemical characterization. As a result of this, Sweden has an environmental classification of diesel fuels which has been in force since 1991. Analogously, the Swedish Environmental Protection Agency has asked whether detrimental environmental and health effects from residential heating can be reduced by selection of fuel properties, and if so by how much? In addition, which properties are most important to control in a future environmental classification of heating oils? As a first step in this process, a literature survey was performed. Major topics were: Sampling technology, chemical composition, biological activity, and risk assessment of emissions. 33 refs, 11 tabs

  2. Energy and exergy analysis of an annular shaft kiln with opposite burners

    International Nuclear Information System (INIS)

    Rong, Wenjie; Li, Baokuan; Qi, Fengsheng; Cheung, Sherman C.P.

    2017-01-01

    Highlights: • An OBASK is investigated for the energy and exergy performance. • The energy and exergy efficiency of the OBASK is of 63.6% and 35.7%, respectively. • The exergy destruction accounts for 44.5% of the total exergy input. - Abstract: Annular shaft kilns with opposite burners (OBASK) has been widely adopted due to the advantages of cost saving and easy controlling. Nonetheless, compared with the traditional annular shaft kiln, the OBASK is not favorable in terms of thermal performance and energy efficiency. Aiming to improve the thermal performance, a comprehensive energy and exergy analysis of an OBASK has been conducted based on the actual operational data obtained from on-site measurements. For making a thorough thermal analysis of the OBASK, special attentions have been focused in considering magnesium decomposition reaction and moisture in limestone in the methodology. The energy and exergy efficiencies are determined to be 63.6% and 35.7%, respectively. The exergy destruction is 44.0% of total exergy input of which fuel combustion causes 56.6% of the exergy destruction. Furthermore, the effects of CaO and moisture contents in limestone on energy and exergy efficiencies are analyzed. The results have demonstrated the potential energy saving of the OBASK and identified three proposed energy conservation measures. Improvement and effect of the three proposed measures on the thermal performance are verified via further analysis.

  3. Fusion-driven actinide burner design study. Second quarterly progress report

    International Nuclear Information System (INIS)

    Chi, J.W.H.; Gold, R.E.; Holman, R.R.

    1975-11-01

    The Second Quarterly Progress Report summarizes the status at the mid-point of the conceptual design effort. The fusion driver continues to pose some of the principal design problems due to the necessity of advancing plasma engineering and technology for long pulse, high duty cycle operation. The development of credible design solutions to these problems is one of the major objectives of the study. The TF and OH coil designs have been modified to provide a more compact arrangement in the nose region of the TF coils and to ensure fully cryostable operation. A unique concept has been developed to effectively shield the TF coils from the poloidal fields. A vacuum vessel concept which separates the functions for sustaining the differential pressure load and for sealing the vacuum system is described. The thickness of the blanket has been decreased to reduce the power density and the actinide inventory. Determination and presentation of actinide depletion characteristics represents a major element thus far in the study and is a principal objective. Evaluation of the changes in the hazard only during irradiation proved to be an inadequate measure of the reduction in long term hazards due to the importance of radioactive daughter products which appear much later in time. Therefore, comparisons have been made of long term decay characteristics before and after irradiation in the actinide burner. It has also been noted that some of the actinides that are produced during irradiation have beneficial applications as radioisotopic power sources. These and other considerations suggest that alternate approaches to assessing the waste management problem be considered to develop a meaningful perspective on long term hazards from the actinides

  4. Fusion-driven actinide burner design study. Second quarterly progress report

    Energy Technology Data Exchange (ETDEWEB)

    Chi, J.W.H.; Gold, R.E.; Holman, R.R.

    1975-11-01

    The Second Quarterly Progress Report summarizes the status at the mid-point of the conceptual design effort. The fusion driver continues to pose some of the principal design problems due to the necessity of advancing plasma engineering and technology for long pulse, high duty cycle operation. The development of credible design solutions to these problems is one of the major objectives of the study. The TF and OH coil designs have been modified to provide a more compact arrangement in the nose region of the TF coils and to ensure fully cryostable operation. A unique concept has been developed to effectively shield the TF coils from the poloidal fields. A vacuum vessel concept which separates the functions for sustaining the differential pressure load and for sealing the vacuum system is described. The thickness of the blanket has been decreased to reduce the power density and the actinide inventory. Determination and presentation of actinide depletion characteristics represents a major element thus far in the study and is a principal objective. Evaluation of the changes in the hazard only during irradiation proved to be an inadequate measure of the reduction in long term hazards due to the importance of radioactive daughter products which appear much later in time. Therefore, comparisons have been made of long term decay characteristics before and after irradiation in the actinide burner. It has also been noted that some of the actinides that are produced during irradiation have beneficial applications as radioisotopic power sources. These and other considerations suggest that alternate approaches to assessing the waste management problem be considered to develop a meaningful perspective on long term hazards from the actinides.

  5. Development of heat transfer calculation program for finned-tune heat exchanger of multi-burner boiler

    International Nuclear Information System (INIS)

    Jang, Sae Byul; Kim, Jong Jin; Ahn, Joon

    2009-01-01

    We develop a heat exchanger modules for a multi-burner boiler. The heat exchanger module is kind of a Heat Recovery Steam Generator (HRSG). This heat recovery system has 8 heat exchanger modules. The 1st module consists of 27 bare tubes due to high temperature exhaust gas and the others consist of 27 finned tubes. The maximum steam pressure of each module is 1 MPa and tested steam pressure is 0.7 MPa. In order to test these heat exchanger modules, we make a 0.5 t/h flue tube boiler (LNG, 40 Nm 3 /h). We tested the heat exchanger module with changing the position of each heat exchanger module. We measured the inlet and outlet temperature of each heat exchanger module and calculated the heat exchange rate. Based on test results, we develop a heat transfer calculation program to predict flue gas. Calculation results show that temperature and temperature difference between measured and calculated flue gas exit temperature is less than 20 .deg. C when flue gas inlet temperature is 620 .deg. C.

  6. Calculational benchmark comparisons for a low sodium void worth actinide burner core design

    International Nuclear Information System (INIS)

    Hill, R.N.; Kawashima, M.; Arie, K.; Suzuki, M.

    1992-01-01

    Recently, a number of low void worth core designs with non-conventional core geometries have been proposed. Since these designs lack a good experimental and computational database, benchmark calculations are useful for the identification of possible biases in performance characteristics predictions. In this paper, a simplified benchmark model of a metal fueled, low void worth actinide burner design is detailed; and two independent neutronic performance evaluations are compared. Calculated performance characteristics are evaluated for three spatially uniform compositions (fresh uranium/plutonium, batch-averaged uranium/transuranic, and batch-averaged uranium/transuranic with fission products) and a regional depleted distribution obtained from a benchmark depletion calculation. For each core composition, the flooded and voided multiplication factor, power peaking factor, sodium void worth (and its components), flooded Doppler coefficient and control rod worth predictions are compared. In addition, the burnup swing, average discharge burnup, peak linear power, and fresh fuel enrichment are calculated for the depletion case. In general, remarkably good agreement is observed between the evaluations. The most significant difference is predicted performance characteristics is a 0.3--0.5% Δk/(kk) bias in the sodium void worth. Significant differences in the transmutation rate of higher actinides are also observed; however, these differences do not cause discrepancies in the performing predictions

  7. Optimization of the deep-burner-modular helium reactor (DB-MHR) concept for actinide incineration

    International Nuclear Information System (INIS)

    Trakas, Ch.; Bruna, G.B.

    2005-01-01

    The paper summarizes studies performed on the General Atomics Deep-Burner Modular Helium Reactor (DB-MHR) concept-design carried out by Framatome ANP, Areva's joint subsidiary with Siemens. Feasibility and sensitivity studies as well as fuel-cycle studies with probabilistic methodology are presented. Emphasis is put on most attractive physical and computational aspects of the concept. Current investigations on design uncertainties, the future search for ways to improve the transmutation value in a double-stratum strategy, and the computational tools improvement are also presented. The Areva HTR, ANTARES, uses a similar prismatic core design. In that context, we revisited and optimized the Deep Burn concept. Typical values of transmutation ratio were established at 70%. Accounting for reactivity control needs estimated at 300 pcm, the cycle length can be estimated at 480 full-power days, giving an overall fuel irradiation time (6 fuel cycles) of about 10 calendar year, assuming as usual an average capacity factor of the plant of 80%. This study indicates a quite significant (96%) achievement for fissile material incineration. After a 500 year cooling-time, radiotoxicity (without fission products) is reduced by a factor 4

  8. Incidental irradiation of mediastinal and hilar lymph node stations during 3D-conformal radiotherapy for non-small cell lung cancer

    International Nuclear Information System (INIS)

    Kepka, Lucyna; Bujko, Krzysztof; Zolciak-Siwinska, Agnieszka; Garmol, Dariusz

    2008-01-01

    Purpose. To estimate the doses of incidental irradiation in particular lymph node stations (LNS) in different extents of elective nodal irradiation (ENI) in 3D-conformal radiotherapy (3D-CRT) for non-small cell lung cancer (NSCLC). Methods. Doses of radiotherapy were estimated for particular LNS delineated according to the recommendations of the Univ. of Michigan in 220 patients treated using 3D-CRT with different (extended, limited and omitted) extents of ENI. Minimum doses and volumes of LNS receiving 40 Gy or more (V40) were compared for omitted vs. limited+extended ENI and limited vs. extended ENI. Results. For omission of the ENI the minimum doses and V40 for particular LNS were significantly lower than for patients treated with ENI. For the limited ENI group, the minimum doses for LNS 5, 6 lower parts of 3A and 3P (not included in the elective area) did not differ significantly from doses given to respective LNS for extended ENI group. When the V40 values for extended and limited ENI were compared, no significant differences were seen for any LNS, except for group 1/2R, 1/2L. Conclusions. Incidental irradiation of untreated LNS seems play a part in case of limited ENI, but not in cases without ENI. For subclinical disease the delineation of uninvolved LNS 5, 6, and lower parts of 3A, 3P may be not necessary, because these stations receive the substantial part of irradiation incidentally, if LNS 4R, 4L, 7, and ipsilateral hilum are included in the elective area while this is not case for stations 1 and 2

  9. Preparation and evaluation of enteric coated tablets of hot-melt extruded lansoprazole.

    Science.gov (United States)

    Alsulays, Bader B; Kulkarni, Vijay; Alshehri, Sultan M; Almutairy, Bjad K; Ashour, Eman A; Morott, Joseph T; Alshetaili, Abdullah S; Park, Jun-Bom; Tiwari, Roshan V; Repka, Michael A

    2017-05-01

    The objective of this work was to use hot-melt extrusion (HME) technology to improve the physiochemical properties of lansoprazole (LNS) to prepare stable enteric coated LNS tablets. For the extrusion process, we chose Kollidon ® 12 PF (K12) polymeric matrix. Lutrol ® F 68 was selected as the plasticizer and magnesium oxide (MgO) as the alkalizer. With or without the alkalizer, LNS at 10% drug load was extruded with K12 and F68. LNS changed to the amorphous phase and showed better release compared to that of the pure crystalline drug. Inclusion of MgO improved LNS extrudability and release and resulted in over 80% drug release in the buffer stage. Hot-melt extruded LNS was physically and chemically stable after 12 months of storage. Both formulations were studied for compatibility with Eudragit ® L100-55. The optimized formulation was compressed into a tablet followed by coating process utilizing a pan coater using L100-55 as an enteric coating polymer. In a two-step dissolution study, the release profile of the enteric coated LNS tablets in the acidic stage was less than 10% of the LNS, while that in the buffer stage was more than 80%. Drug content analysis revealed the LNS content to be 97%, indicating the chemical stability of the enteric coated tablet after storage for six months. HME, which has not been previously used for LNS, is a valuable technique to reduce processing time in the manufacture of enteric coated formulations of an acid-sensitive active pharmaceutical ingredient as compared to the existing methods.

  10. Evaluation of 18F-FDG PET/CT Parameters for Detection of Lymph Node Metastasis in Cutaneous Melanoma.

    Science.gov (United States)

    Cha, Jongtae; Kim, Soyoung; Wang, Jiyoung; Yun, Mijin; Cho, Arthur

    2018-02-01

    The purpose of this study was to investigate the value of 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) parameters in the detection of regional lymph node (LN) metastasis in patients with cutaneous melanoma. We evaluated patients with cutaneous melanoma who underwent FDG PET/CT for initial staging or recurrence evaluation. A total of 103 patients were enrolled, and 165 LNs were evaluated. LNs that were confirmed pathologically or by follow-up imaging were included in this study. PET parameters, including maximum standardized uptake value (SUVmax), total lesion glycolysis and tumour-to-liver ratio, were used to determine the presence of metastases, and the results were compared with CT-determined LN metastasis. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cut-off values of the FDG PET parameters. A total of 93 LNs were malignant, and 84 LNs were smaller than 10 mm. In all 165 LNs, an SUVmax of >2.51 showed a sensitivity of 73.1%, a specificity of 88.9%, and an accuracy of 80.0% in detecting metastatic LNs. CT showed a higher specificity (87.3%) and lower accuracy (65.5%). For non-enlarged regional LNs (2.4 showed a high sensitivity (91%) and accuracy (89%) in detecting metastasis in LNs ≥1 cm, and LNs <1 cm with an SUVmax <1.4 were likely to be benign.

  11. Influence of staged-air on airflow, combustion characteristics and NO(x) emissions of a down-fired pulverized-coal 300 MW(e) utility boiler with direct flow split burners.

    Science.gov (United States)

    Li, Zhengqi; Kuang, Min; Zhang, Jia; Han, Yunfeng; Zhu, Qunyi; Yang, Lianjie; Kong, Weiguang

    2010-02-01

    Cold airflow experiments were conducted to investigate the aerodynamic field in a small-scale furnace of a down-fired pulverized-coal 300 MW(e) utility boiler arranged with direct flow split burners enriched by cyclones. By increasing the staged-air ratio, a deflected flow field appeared in the lower furnace; larger staged-air ratios produced larger deflections. Industrial-sized experiments on a full-scale boiler were also performed at different staged-air damper openings with measurements taken of gas temperatures in the burner region and near the right-side wall, wall heat fluxes, and gas components (O(2), CO, and NO(x)) in the near-wall region. Combustion was unstable at staged-air damper openings below 30%. For openings of 30% and 40%, late ignition of the pulverized coal developed and large differences arose in gas temperatures and heat fluxes between the regions near the front and rear walls. In conjunction, carbon content in the fly ash was high and boiler efficiency was low with high NO(x) emission above 1200 mg/m(3) (at 6% O(2) dry). For fully open dampers, differences in gas temperatures and heat fluxes, carbon in fly ash and NO(x) emission decreased yielding an increase in boiler efficiency. The optimal setting is fully open staged-air dampers.

  12. In-flight particle measurement of glass raw materials in hybrid heating of twelve-phase AC arc with oxygen burner

    International Nuclear Information System (INIS)

    Liu, Y; Tanaka, M; Ikeba, T; Choi, S; Watanabe, T

    2012-01-01

    The high temperature provided by a 12-phase AC arc plasma is beneficial to finish vitrification reaction in milliseconds. Another heating method called “hybrid plasma” combines multi-phase AC arc and oxygen burner are expected to improve glass quality and increase productivity with minimum energy consumption. In this study, recent works on the development of in-flight particle measurement in hybrid plasma system are presented. Two-colour pyrometry offers considerable advantages for measuring particle temperatures in flight. A high-speed camera equipped with a band-pass filter system was applied to measure the in-flight temperatures of glass particles. The intensity recorded by the camera was calibrated using a tungsten halogen lamp. This technique also allows evaluating the fluctuation of the average particle temperature within millisecond in plasma region.

  13. Are Radiation Therapy Oncology Group Para-aortic Contouring Guidelines for Pancreatic Neoplasm Applicable to Other Malignancies—Assessment of Nodal Distribution in Gynecological Malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Kabolizadeh, Peyman; Fulay, Suyash; Beriwal, Sushil, E-mail: beriwals@upmc.edu

    2013-09-01

    Purpose: Intensity modulated radiation therapy is used to reduce dose to adjacent critical structures while maintaining adequate target coverage, but it requires precise target localization. We report the 3-dimensional distribution of para-aortic (PA) lymph nodes (LN) in pelvic malignancies. We propose a guideline to accurately define the PA LN by anatomic landmarks and compare our data with published guidelines for pancreatic cancer. Methods and Materials: A retrospective analysis was performed on 46 patients with pelvic malignancies and positive PA LNs. Positive LNs were defined based on size and morphology or fluorodeoxyglucose avidity. All PA LNs were characterized into 3 groups based on location: left PA (between aorta and left psoas muscle), aortocaval (between aorta and inferior vena cava), and right paracaval (between inferior vena cava and right psoas muscle). Patients with retrocrural LNs were also analyzed. Results: One hundred thirty-three positive PA LNs were evaluated. The majority of the PA LNs were in the left PA (59%) and aortocaval (35) regions, and only 8% were in the right paracaval region. All patients with positive right paracaval LNs also had involved left PA LNs, with only 1 exception. The highest PA LN involvement was at the level of the renal vessels and was seen in 28% of patients. Of these patients with disease extending to renal vessels, 38% had retrocrural LN involvement. Conclusions: The nodal contouring for the PA region should not be defined by a fixed circumferential margin around the vessels. The left PA and aortocaval spaces should be covered adequately because these are common locations of PA LNs. For microscopic disease superiorly, contouring should extend up to renal vessels rather than a fixed bony landmark. For patients who have nodal involvement at renal vessels, one can consider including retrocrural LNs. Radiation Therapy Oncology Group Para-aortic Contouring Guidelines for Pancreatic Neoplasm are not applicable to

  14. Are Radiation Therapy Oncology Group Para-aortic Contouring Guidelines for Pancreatic Neoplasm Applicable to Other Malignancies—Assessment of Nodal Distribution in Gynecological Malignancies

    International Nuclear Information System (INIS)

    Kabolizadeh, Peyman; Fulay, Suyash; Beriwal, Sushil

    2013-01-01

    Purpose: Intensity modulated radiation therapy is used to reduce dose to adjacent critical structures while maintaining adequate target coverage, but it requires precise target localization. We report the 3-dimensional distribution of para-aortic (PA) lymph nodes (LN) in pelvic malignancies. We propose a guideline to accurately define the PA LN by anatomic landmarks and compare our data with published guidelines for pancreatic cancer. Methods and Materials: A retrospective analysis was performed on 46 patients with pelvic malignancies and positive PA LNs. Positive LNs were defined based on size and morphology or fluorodeoxyglucose avidity. All PA LNs were characterized into 3 groups based on location: left PA (between aorta and left psoas muscle), aortocaval (between aorta and inferior vena cava), and right paracaval (between inferior vena cava and right psoas muscle). Patients with retrocrural LNs were also analyzed. Results: One hundred thirty-three positive PA LNs were evaluated. The majority of the PA LNs were in the left PA (59%) and aortocaval (35) regions, and only 8% were in the right paracaval region. All patients with positive right paracaval LNs also had involved left PA LNs, with only 1 exception. The highest PA LN involvement was at the level of the renal vessels and was seen in 28% of patients. Of these patients with disease extending to renal vessels, 38% had retrocrural LN involvement. Conclusions: The nodal contouring for the PA region should not be defined by a fixed circumferential margin around the vessels. The left PA and aortocaval spaces should be covered adequately because these are common locations of PA LNs. For microscopic disease superiorly, contouring should extend up to renal vessels rather than a fixed bony landmark. For patients who have nodal involvement at renal vessels, one can consider including retrocrural LNs. Radiation Therapy Oncology Group Para-aortic Contouring Guidelines for Pancreatic Neoplasm are not applicable to

  15. Evaluation of lymph node numbers for adequate staging of Stage II and III colon cancer

    Directory of Open Access Journals (Sweden)

    Bumpers Harvey L

    2011-05-01

    Full Text Available Abstract Background Although evaluation of at least 12 lymph nodes (LNs is recommended as the minimum number of nodes required for accurate staging of colon cancer patients, there is disagreement on what constitutes an adequate identification of such LNs. Methods To evaluate the minimum number of LNs for adequate staging of Stage II and III colon cancer, 490 patients were categorized into groups based on 1-6, 7-11, 12-19, and ≥ 20 LNs collected. Results For patients with Stage II or III disease, examination of 12 LNs was not significantly associated with recurrence or mortality. For Stage II (HR = 0.33; 95% CI, 0.12-0.91, but not for Stage III patients (HR = 1.59; 95% CI, 0.54-4.64, examination of ≥20 LNs was associated with a reduced risk of recurrence within 2 years. However, examination of ≥20 LNs had a 55% (Stage II, HR = 0.45; 95% CI, 0.23-0.87 and a 31% (Stage III, HR = 0.69; 95% CI, 0.38-1.26 decreased risk of mortality, respectively. For each six additional LNs examined from Stage III patients, there was a 19% increased probability of finding a positive LN (parameter estimate = 0.18510, p Conclusions Thus, the 12 LN cut-off point cannot be supported as requisite in determining adequate staging of colon cancer based on current data. However, a minimum of 6 LNs should be examined for adequate staging of Stage II and III colon cancer patients.

  16. A NEW DOUBLE-SLIT CURVED WALL-JET (CWJ) BURNER FOR STABILIZING TURBULENT PREMIXED AND NON-PREMIXED FLAMES

    KAUST Repository

    Mansour, Morkous S.; Chung, Suk-Ho

    2015-01-01

    Mixing characteristics in the cold flow of non-premixed cases were first examined using acetone fluorescence technique, indicating substantial transport between the fuel and air by exhibiting appreciable premixing conditions.PIV measurements revealed that velocity gradients in the shear layers at the boundaries of the annularjets generate the turbulence, enhanced with the collisions in the interaction jet, IJ,region. Turbulent mean and rms velocities were influenced significantly by Re and high rms turbulent velocities are generated within the recirculation zone improving the flame stabilization in this burner.Premixed and non-premixed flames with high equivalence ratio were found to be more resistant to local extinction and exhibited a more corrugated and folded nature, particularly at high Re. For flames with low equivalence ratio, the processes of local quenching at IJ region and of re-ignition within merged jet region maintained these flames further downstream particularly for non-premixed methane flame, revealing a strong intermittency.

  17. Integrated solar-assisted heat pumps for water heating coupled to gas burners; control criteria for dynamic operation

    International Nuclear Information System (INIS)

    Scarpa, F.; Tagliafico, L.A.; Tagliafico, G.

    2011-01-01

    A direct expansion integrated solar-assisted heat pump (ISAHP) is compared to a traditional flat plate solar panel for low temperature (45 deg. C) water heating applications. The (simulated) comparison is accomplished assuming both the devices are energy supplemented with an auxiliary standard gas burner, to provide the typical heat duty of a four-member family. Literature dynamical models of the systems involved have been used to calculate the main performance figures in a context of actual climatic conditions and typical stochastic user demand. The paper highlights new heat pump control concepts, needed when maximum energy savings are the main goal of the apparatus for given user demand. Simulations confirm the high collector efficiency of the ISAHP when its panel/evaporator works at temperature close to the ambient one. The device, with respect to a flat plate solar water heater, shows a doubled performance, so that it can do the same task just using an unglazed panel with roughly half of the surface.

  18. Differentiating metastatic from nonmetastatic lymph nodes in cervical cancer patients using monoexponential, biexponential, and stretched exponential diffusion-weighted MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qingxia; Wang, Meiyun; Shi, Dapeng [Radiological Department of Henan Provincial People' s Hospital, Zhengzhou, Henan (China); Zheng, Dandan [GE Healthcare, MR Research China, Beijing (China); Shi, Ligang [Pathological Department of Henan Provincial People' s Hospital, Zhengzhou, Henan (China); Liu, Mingbo [Radiotherapeutical Department of Henan Provincial People' s Hospital, Zhengzhou, Henan (China)

    2017-12-15

    To determine the diagnostic value of monoexponential, biexponential and stretched exponential models for identifying lymph nodes (LNs) in patients with cervical cancer. Fifty female patients with cervical cancer underwent preoperative magnetic resonance imaging. The diffusion parameters of the LNs were calculated by fitting the values to monoexponential, biexponential and stretched exponential models and were compared between the metastatic and non-metastatic LN groups. A total of 157 LNs with high signal intensity on multi-b-value DWI were detected, 41 of which were pathologically shown to be metastatic. Metastatic LNs presented with higher pure water diffusion (D) values, lower perfusion fraction (f) values, higher diffusion heterogeneity (α) values, higher short diameter (Size-S), long diameter (Size-L) and short long diameter ratio (S/L Ratio) than non-metastatic LNs (P<0.05). The Size-S of LNs exhibited the highest diagnostic value, with an area under the curve of 0.844. Compared with the size parameters, the diffusion parameters derived from multi-b-value diffusion-weighted imaging cannot reliably discriminate metastatic from non-metastatic LNs in daily clinical routine due to limited sensitivity and specificity. (orig.)

  19. Measurements of the concentration of major chemical species in the flame of a test burner with a air swirling system; Mesures de concentration d`especes chimiques majoritaires dans la flamme d`un bruleur modele avec mise en rotation de l`air

    Energy Technology Data Exchange (ETDEWEB)

    Albert, St. [Gaz de France (GDF), 93 - La Plaine-Saint-Denis (France); Most, J.M.; Poireault, B. [Centre National de la Recherche Scientifique (CNRS), 86 - Poitiers (France)

    1996-12-31

    The study of combustion in industrial burners remains difficult because of the complexity of the equipments used: materials geometry, tri-dimensional flows etc.. The phenomena that control the combustion in a gas burner with a swirl air system has been studied thanks to a collaboration between the Direction of Research of Gaz de France (GdF) and the Laboratory for Combustion and Detonation Research (LCD) of the French National Centre of Scientific Research (CNRS). The burner used is developed by the LCD and the measurements of stable chemical species were performed by the CERSTA centre of GdF. These series of tests, performed in confined environment, have permitted to identify some of the parameters that influence combustion chemistry. Mapping of chemical species allows to distinguish 5 zones of flame development and also the zones of nitrogen oxides formation. Methane is rapidly centrifuged a few millimeters above the injection pipe and centrifuged with rotating combustion air. Carbon monoxide occurs immediately in the central recirculation zone which is weakly reactive (no oxygen and no methane). Oxygen content increases downflow from this area and carbon dioxide reaches its concentration maxima. CO formation decreases when the swirl number increases and CO{sub 2} formation occurs earlier. On the contrary, the emissions of CO and CH{sub 4} do not depend on the swirl value and the NO{sub x} values are only slightly dependent on this value. (J.S.)

  20. Premixed Combustion of Kapok (ceiba pentandra seed oil on Perforated Burner

    Directory of Open Access Journals (Sweden)

    I.K.G. Wirawan

    2014-05-01

    Full Text Available Availability of fossil fuels in the world decrease gradually due to excessive fuel exploitation. This situations push researcher to look for alternative fuels as a source of renewable energy, one of them is kapok (ceiba pentandra seed oil. The aim this study was to know the behavior of laminar burning velocity, secondary Bunsen flame with open tip, cellular and triple flame. Premixed combustion of kapok seed oil was studied experimentally on perforated burner with equivalence ratio (φ varied from 0.30 until 1.07. The results showed that combustion of glycerol requires a large amount of air so that laminar burning velocity (SL is the highest at very lean mixture (φ =0.36 in the form of individual Bunsen flame on each of the perforated plate hole.  Perforated and secondary Bunsen flame both reached maximum SL similar with that of ethanol and higher than that of hexadecane. Slight increase of φ decreases drastically SL of perforated and secondary Bunsen flame. When the mixture was enriched, secondary Bunsen and perforated flame disappears, and then the flame becomes Bunsen flame with open tip and triple flame (φ = 0.62 to 1.07. Flame was getting stable until the mixture above the stoichiometry. Being isolated from ambient air, the SL of perforated flame, as well as secondary Bunsen flame, becomes equal with non-isolated flame. This shows the decreasing trend of laminar burning velocity while φ is increasing. When the mixture was enriched island (φ = 0.44 to 0.48 and petal (φ = 0.53 to 0.62 cellular flame take place. Flame becomes more unstable when the mixture was changed toward stoichiometry.

  1. Willingness to pay for small-quantity lipid-based nutrient supplements for women and children: Evidence from Ghana and Malawi.

    Science.gov (United States)

    Adams, Katherine P; Vosti, Stephen A; Ayifah, Emmanuel; Phiri, Thokozani E; Adu-Afarwuah, Seth; Maleta, Kenneth; Ashorn, Ulla; Arimond, Mary; Dewey, Kathryn G

    2018-04-01

    Small-quantity lipid-based nutrient supplements (SQ-LNS) are designed to enrich maternal and child diets with the objective of preventing undernutrition during the first 1,000 days. Scaling up the delivery of supplements such as SQ-LNS hinges on understanding private demand and creatively leveraging policy-relevant factors that might influence demand. We used longitudinal stated willingness-to-pay (WTP) data from contingent valuation studies that were integrated into randomized controlled nutrition trials in Ghana and Malawi to estimate private valuation of SQ-LNS during pregnancy, postpartum, and early childhood. We found that average stated WTP for a day's supply of SQ-LNS was more than twice as high in Ghana than Malawi, indicating that demand for SQ-LNS (and by extension, the options for effective delivery of SQ-LNS) may be very context specific. We also examined factors associated with WTP, including intervention group, household socioeconomic status, birth outcomes, child growth, and maternal and child morbidity. In both sites, WTP was consistently negatively associated with household food insecurity, indicating that subsidization might be needed to permit food insecure households to acquire SQ-LNS if it is made available for purchase. In Ghana, WTP was higher among heads of household than among mothers, which may be related to control over household resources. Personal experience using SQ-LNS was not associated with WTP in either site. © 2017 The Authors. Maternal and Child Nutrition published by John Wiley & Sons, Ltd.

  2. Ultrasonic detection of lymph nodes in stomach cancer: Around celiac axis

    International Nuclear Information System (INIS)

    Lim, An Lee; Yang, Gyu Seob; Yoon, Chong Hyun

    1990-01-01

    From January 1987 to December 1989, we did ultrasound examination for lymph nodes(LNs) around the celiac axis in 159 patients of stomach cancer. And surgically removed LNs were correlated with sonographic result and pathologic confirmation for metastasis. The celiac axis as a landmark for location of LN was identified in 87%(138/159). On ultrasonic examination. 77 LNs were detected around the celiac axis from 62 patients, however no LNs was detected from the remaining 97 patients. In detail, the outputs of pathologic correlation are; sensitivity=80%(35/44), specificity=77%(88/115), overall accuracy=77%. When the size criteria was designated as diameters of 10, 15 and 20 mm, sensitivity was 89%, 68% and 39%, whereas the specificity was 55%, 79%, and 97% respectively. On the analysis of LNs according to their sizes, LNs with diameter of above 15 mm were significant for diagnosis of LN metastasis(P value<0.0005). On the analysis of LNs according to their shapes, LN with notched or lobulated margin was more significant than LN with discrete margin, especially when diameter of LN was below 15 mm. However the shape of LN played not so big role, when diameter of LN was above 15 mm

  3. Environmental Assessment for the Commercial Demonstration of the Low NOx Burner/Separated Over-Fire Air (LNB/SOFA) Integration System Emission Reduction Technology, Finney County, Kansas

    Energy Technology Data Exchange (ETDEWEB)

    n/a

    2003-03-11

    The U.S. Department of Energy (DOE) proposes to provide partial funding to the Sunflower Electric Power Corporation (Sunflower), to demonstrate the commercial application of Low-NO{sub x} Burner/Separated Over-Fire Air (LNB/SOFA) integration system to achieve NO{sub x} emission reduction to the level of 0.15 to 0.22 pounds per million British thermal units (lb/MM Btu). The proposed project station is Sunflower's 360 MW coal-fired generation station, Holcomb Unit No. 1 (Holcomb Station). The station, fueled by coal from Wyoming's Powder River Basin, is located near Garden City, in Finney County, Kansas. The period of performance is expected to last approximately 2 years. The Holcomb Station, Sunflower LNB/SOFA integrated system would be modified in three distinct phases to demonstrate the synergistic effect of layering NO{sub x} control technologies. Once modified, the station would demonstrate that a unit equipped with an existing low-NO{sub x} burner system can be retrofitted with a new separated over-fire air (SOFA) system, coal flow measurement and control, and enhanced combustion monitoring to achieve about 45 percent reduction in nitrogen oxides (NO{sub x}) emissions. The proposed project would demonstrate a technology alternative to Selective Catalytic Reduction (SCR) systems. While SCR does generally achieve high reductions in NO{sub x} emissions (from about 0.8 lb/MM to 0.12 lb/MM Btu), it does so at higher capital and operating cost, requires the extensive use of critical construction labor, requires longer periods of unit outage for deployment, and generally requires longer periods of time to complete shakedown and full-scale operation. Cost of the proposed project technology would be on the order of 15-25 percent of that for SCR, with consequential benefits derived from reductions in construction manpower requirements and periods of power outages. This proposed technology demonstration would generally be applicable to boilers using opposed

  4. Applicability of RELAP5-3D for Thermal-Hydraulic Analyses of a Sodium-Cooled Actinide Burner Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    C. B. Davis

    2006-07-01

    The Actinide Burner Test Reactor (ABTR) is envisioned as a sodium-cooled, fast reactor that will burn the actinides generated in light water reactors to reduce nuclear waste and ease proliferation concerns. The RELAP5-3D computer code is being considered as the thermal-hydraulic system code to support the development of the ABTR. An evaluation was performed to determine the applicability of RELAP5-3D for the analysis of a sodium-cooled fast reactor. The applicability evaluation consisted of several steps, including identifying the important transients and phenomena expected in the ABTR, identifying the models and correlations that affect the code’s calculation of the important phenomena, and evaluating the applicability of the important models and correlations for calculating the important phenomena expected in the ABTR. The applicability evaluation identified code improvements and additional models needed to simulate the ABTR. The accuracy of the calculated thermodynamic and transport properties for sodium was also evaluated.

  5. Employment status, employment functioning, and barriers to employment among VA primary care patients.

    Science.gov (United States)

    Zivin, Kara; Yosef, Matheos; Levine, Debra S; Abraham, Kristen M; Miller, Erin M; Henry, Jennifer; Nelson, C Beau; Pfeiffer, Paul N; Sripada, Rebecca K; Harrod, Molly; Valenstein, Marcia

    2016-03-15

    Prior research found lower employment rates among working-aged patients who use the VA than among non-Veterans or Veterans who do not use the VA, with the lowest reported employment rates among VA patients with mental disorders. This study assessed employment status, employment functioning, and barriers to employment among VA patients treated in primary care settings, and examined how depression and anxiety were associated with these outcomes. The sample included 287 VA patients treated in primary care in a large Midwestern VA Medical Center. Bivariate and multivariable analyses were conducted examining associations between socio-demographic and clinical predictors of six employment domains, including: employment status, job search self-efficacy, work performance, concerns about job loss among employed Veterans, and employment barriers and likelihood of job seeking among not employed Veterans. 54% of respondents were employed, 36% were not employed, and 10% were economically inactive. In adjusted analyses, participants with depression or anxiety (43%) were less likely to be employed, had lower job search self-efficacy, had lower levels of work performance, and reported more employment barriers. Depression and anxiety were not associated with perceived likelihood of job loss among employed or likelihood of job seeking among not employed. Single VA primary care clinic; cross-sectional study. Employment rates are low among working-aged VA primary care patients, particularly those with mental health conditions. Offering primary care interventions to patients that address mental health issues, job search self-efficacy, and work performance may be important in improving health, work, and economic outcomes. Published by Elsevier B.V.

  6. FDG uptake and glut-1 expression in primary tumors and loco-regional lymph nodes in non-small-cell lung cancer

    International Nuclear Information System (INIS)

    Lee, Won Woo; Nguyen, Xuan Canh; Chung, Jin Haeng; Park, So Yeon; Kim, Sang Eun

    2007-01-01

    FDG uptake level by primary tumors in NSCLC may affect the likelihood of malignant involvement in loco-regional lymph nodes (LNs). FDG uptake in tumors has been reported to be mediated by glucose transporter type 1 (Glut-I). Here, we investigated the correlations between primary tumors and loco-regional LNs in NSCLC regarding FDG uptake and Glut-1 expression. 126 NSCLC patients (M: F=103: 23, age=659.7y) who underwent curative resection and loco-regional LN dissection within 4 week period after FDG-PET study were enrolled. Maximum standardized uptake value (maxSUV) by PET and %Glut-1 expression by immunostaining were compared between primary tumors and FDG uptake positive loco-regional LNs. Significant correlations were found between 52 malignant LNs and 37 primary tumors in terms of maxSUV (r=0.6451, p<0.0001) and %Glut-1 expression (r=0.8341, p<0.0001). Linear regression of the relation between maxSUVs of malignant LNs (Y) and maxSUVs of primary tumors (X) yielded the expression Y = 0.5938 + 0.4808 X with an r2 value of 0.4162. On the other hand, no significant correlation was observed between 144 benign LNs and 75 primary tumors in terms of maxSUVs (r= -0.0125, p 0.8831). Moreover, %Glut-1 expressions of pathologically proven benign LNs and primary tumors were found to be correlated (r=0.3863, p=0.0004), but r2 value was low at 0.1492. High correlations were found between primary tumors and loco-regional metastatic LNs in NSCLC regarding FDG uptake and Glut-1 expression. Mediastinal LN staging of NSCLC by FDG-PET may be improved by considering the linear correlation between FDG uptakes of metastatic LNs and primary tumors

  7. Mapping the distinctive populations of lymphatic endothelial cells in different zones of human lymph nodes.

    Directory of Open Access Journals (Sweden)

    Saem Mul Park

    Full Text Available The lymphatic sinuses in human lymph nodes (LNs are crucial to LN function yet their structure remains poorly defined. Much of our current knowledge of lymphatic sinuses derives from rodent models, however human LNs differ substantially in their sinus structure, most notably due to the presence of trabeculae and trabecular lymphatic sinuses that rodent LNs lack. Lymphatic sinuses are bounded and traversed by lymphatic endothelial cells (LECs. A better understanding of LECs in human LNs is likely to improve our understanding of the regulation of cell trafficking within LNs, now an important therapeutic target, as well as disease processes that involve lymphatic sinuses. We therefore sought to map all the LECs within human LNs using multicolor immunofluorescence microscopy to visualize the distribution of a range of putative markers. PROX1 was the only marker that uniquely identified the LECs lining and traversing all the sinuses in human LNs. In contrast, LYVE1 and STAB2 were only expressed by LECs in the paracortical and medullary sinuses in the vast majority of LNs studied, whilst the subcapsular and trabecular sinuses lacked these molecules. These data highlight the existence of at least two distinctive populations of LECs within human LNs. Of the other LEC markers, we confirmed VEGFR3 was not specific for LECs, and CD144 and CD31 stained both LECs and blood vascular endothelial cells (BECs; in contrast, CD59 and CD105 stained BECs but not LECs. We also showed that antigen-presenting cells (APCs in the sinuses could be clearly distinguished from LECs by their expression of CD169, and their lack of expression of PROX1 and STAB2, or endothelial markers such as CD144. However, both LECs and sinus APCs were stained with DCN46, an antibody commonly used to detect CD209.

  8. Soldiers’ employment attitude and employability: An exploratory study

    Directory of Open Access Journals (Sweden)

    Peng Gao

    2015-04-01

    Full Text Available Purpose: Nowadays it is very difficult for Chinese retired soldiers to find proper jobs, and the primary reason is the significant gap between job requirements and soldiers owned job skills. Therefore, it is very important to improve the soldiers’ job skills and enhance their understanding of employment.Design/methodology/approach: This paper expands the study scope from the soldiers’ job skills to the employability, initiatively introduces the employment attitude which has obvious impact on the employment of soldiers, and analyses the influence that employment attitude can play on employability. At last, this paper develops statistical method to find the relationship between soldiers’ employment attitude and employability.Findings: The empirical analysis shows that soldiers’ employment attitude has the positive linkage with employability, which makes the employment attitude a measurable variable for the employability rather than an absolute standard.Research limitations/implications: According to the research purpose, more variables should be considered in the model, consequently, there are only three indicators to describe solders’ employment attitude and four indicators to describe solders’ employability.Originality/value: This paper takes research on soldiers’ employability in a new perspective. The soldiers’ employment attitude is served as the entry point, showing the influence that soldiers’ employment attitude has on employability.

  9. Numerical Simulation of the Thermal Process in a W-Shape Radiant Tube Burner

    Science.gov (United States)

    Wang, Yi; Li, Jiyong; Zhang, Lifeng; Ling, Haitao; Li, Yanlong

    2014-07-01

    In the current work, three-dimensional mathematical models were developed for the heat transfer and combustion in a W-shape radiant tube burner (RTB) and were solved using Fluent software (ANSYS Inc., Canonsburg, PA). The standard k- ɛ model, nonpremixed combustion model, and the discrete ordinate model were used for the modeling of turbulence, combustion, and radiant heat transfer, respectively. In addition, the NO x postprocessor was used for the prediction of the NO emission. A corresponding experiment was performed for the validation of mathematical models. The details of fluid flow, heat transfer, and combustion in the RTB were investigated. Moreover, the effect of the air/fuel ratio (A/F) and air staging on the performance of RTB was studied with the reference indexes including heat efficiency, maximum temperature difference on shell wall, and NO emission at the outlet. The results indicated that a low speed zone formed in the vicinity of the combustion chamber outlet, and there were two relative high-temperature zones in the RTB, one in combustion chamber that favored the flame stability and the other from the main flame in the RTB. The maximum temperature difference was 95.48 K. As the A/F increased, the temperature increased first and then decreased. As the ratio of the primary to secondary air increased, the recirculation zone at the outlet of combustion chamber shrank gradually to disappear, and the flame length was longer and the temperature in flame decreased correspondingly.

  10. NASA GRC's High Pressure Burner Rig Facility and Materials Test Capabilities

    Science.gov (United States)

    Robinson, R. Craig

    1999-01-01

    The High Pressure Burner Rig (HPBR) at NASA Glenn Research Center is a high-velocity. pressurized combustion test rig used for high-temperature environmental durability studies of advanced materials and components. The facility burns jet fuel and air in controlled ratios, simulating combustion gas chemistries and temperatures that are realistic to those in gas turbine engines. In addition, the test section is capable of simulating the pressures and gas velocities representative of today's aircraft. The HPBR provides a relatively inexpensive. yet sophisticated means for researchers to study the high-temperature oxidation of advanced materials. The facility has the unique capability of operating under both fuel-lean and fuel-rich gas mixtures. using a fume incinerator to eliminate any harmful byproduct emissions (CO, H2S) of rich-burn operation. Test samples are easily accessible for ongoing inspection and documentation of weight change, thickness, cracking, and other metrics. Temperature measurement is available in the form of both thermocouples and optical pyrometery. and the facility is equipped with quartz windows for observation and video taping. Operating conditions include: (1) 1.0 kg/sec (2.0 lbm/sec) combustion and secondary cooling airflow capability: (2) Equivalence ratios of 0.5- 1.0 (lean) to 1.5-2.0 (rich), with typically 10% H2O vapor pressure: (3) Gas temperatures ranging 700-1650 C (1300-3000 F): (4) Test pressures ranging 4-12 atmospheres: (5) Gas flow velocities ranging 10-30 m/s (50-100) ft/sec.: and (6) Cyclic and steady-state exposure capabilities. The facility has historically been used to test coupon-size materials. including metals and ceramics. However complex-shaped components have also been tested including cylinders, airfoils, and film-cooled end walls. The facility has also been used to develop thin-film temperature measurement sensors.

  11. Evaluation of dual energy spectral CT in differentiating metastatic from non-metastatic lymph nodes in rectal cancer: Initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Huanhuan [Department of Radiology, Ruijin Hospital Affiliated to Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China); Department of Radiology, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine (China); Yan, Fuhua; Pan, Zilai; Lin, Xiaozhu; Luo, Xianfu; Shi, Cen [Department of Radiology, Ruijin Hospital Affiliated to Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China); Chen, Xiaoyan [Department of Pathology, Ruijin Hospital Affiliated to Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China); Wang, Baisong [Department of Biomedical Statistics, Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China); Zhang, Huan, E-mail: huanzhangy@126.com [Department of Radiology, Ruijin Hospital Affiliated to Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China)

    2015-02-15

    Highlights: • Colorectal cancer is the third most prevalent cancer and the status of the regional lymph nodes in rectal cancer is considered to be one of the most powerful prognostic factor in the absence of distant metastatic disease. Detecting LNs metastasis is still a challenging problem due to the presence of microscopic metastasis or inflammatory swelling of LNs. • We investigated the value of dual energy spectral CT in differentiating metastatic from non-metastatic lymph nodes in rectal cancer. Our study demonstrated that the quantitative normalized iodine concentration (nIC) could be useful for differentiating metastatic and non-metastatic lymph nodes. The combination of nIC in portal venous phase and conventional size criterion could improve the diagnostic accuracy, sensitivity, specificity, positive predictive value and negative predictive value of rectal cancer. - Abstract: Objectives: To investigate the value of dual energy spectral CT (DEsCT) imaging in differentiating metastatic from non-metastatic lymph nodes in rectal cancer. Methods: Fifty-five patients with rectal cancer underwent the arterial phase (AP) and portal venous phase (PP) contrast-enhanced DEsCT imaging. The virtual monochromatic images and iodine-based material decomposition images derived from DEsCT imaging were interpreted for lymph nodes (LNs) measurement. The short axis diameter and the normalized iodine concentration (nIC) of metastatic and non-metastatic LNs were measured. The two-sample t test was used to compare the short axis diameters and nIC values of metastatic and non-metastatic LNs. ROC analysis was performed to assess the diagnostic performance. Results: One hundred and fifty two LNs including 92 non-metastatic LNs and 60 metastatic LNs were matched using the radiological-pathological correlation. The mean short axis diameter of metastatic LNs was significantly larger than that of the non-metastatic LNs (7.28 ± 2.28 mm vs. 4.90 ± 1.64 mm, P < 0.001). The mean n

  12. Multidetector CT Assessment of Lymph Node Size for Nodal Staging in Patients with Potentially Operable Squamous Esophageal Cancer and the 18F-FDG Positron Emission Tomography CT Correlation

    International Nuclear Information System (INIS)

    Yoom, Soo Kyung; Jung, Jung Im; Ahn, Myeong Im; Park, Jae Gil; Yoo, Ie Ryung; Park, Seog Hee; Park, Mi Jung; Park, Hyun Jin

    2010-01-01

    To investigate the size criteria of multidetector computed tomography (MDCT) for the evaluation metastatic lymph nodes (LNs) for potentially operable squamous esophageal cancer, and to compare this information with the results of positron emission tomography-CT (PET-CT). Twenty-four patients who underwent radical esophagectomy for esophageal cancer were studied. All patients had preoperative MDCT and PET-CT. The MDCT findings were compared with those of PET-CT and were correlated with the surgical records. The receiver operating characteristic (ROC) curve method was used to determine the appropriate cut-off value to distinguish benign from metastatic LNs. The size of metastatic LNs (9.35 ± 3.41 mm) was significantly larger than that of benign LNs (5.74 ± 1.64 mm) (p<0.001). The best cut-off value was 7 mm (81.8% sensitivity, 80.8% specificity). PET-CT detected all metastatic LNs except for four in the peritumoral region. The sensitivity and specificity of metastatic LN evaluation on PET-CT were 82.6% and 99.4%, respectively. Only one LN without metastasis showed increased fluoro-2-deoxy-D-glucose uptake on PET-CT. Size of metastatic LNs can typically be < 10 mm. For MDCT, the short diameter of 7 mm may be the optimal criterion. PET-CT is very accurate for the assessment of metastatic LNs except for those in the peritumoral region

  13. The diagnostic ability of {sup 18}F-FDG PET/CT for mediastinal lymph node staging using {sup 18}F-FDG uptake and volumetric CT histogram analysis in non-small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Won [Catholic Kwandong University College of Medicine, Department of Nuclear Medicine, International St. Mary' s Hospital, Incheon (Korea, Republic of); Kim, Eun Young [Yonsei University College of Medicine, Division of Pulmonology, Department of Internal Medicine, Seoul (Korea, Republic of); Kim, Dae Joon [Yonsei University College of Medicine, Department of Thoracic and Cardiovascular Surgery, Seoul (Korea, Republic of); Lee, Jae-Hoon [Yonsei University College of Medicine, Department of Nuclear Medicine, Seoul (Korea, Republic of); Yonsei University College of Medicine, Department of Nuclear Medicine, Gangnam Severance Hospital, Seoul (Korea, Republic of); Kang, Won Jun; Yun, Mijin [Yonsei University College of Medicine, Department of Nuclear Medicine, Seoul (Korea, Republic of); Lee, Jong Doo [Catholic Kwandong University College of Medicine, Department of Radiology, International St. Mary' s Hospital, Incheon (Korea, Republic of)

    2016-12-15

    To evaluate the clinical implications of lymph node (LN) density on {sup 18}F-FDG PET/CT for mediastinal LN characterization in non-small cell lung cancer (NSCLC). One hundred and fifty-two patients with 271 mediastinal LNs who underwent PET/CT and endobronchial ultrasound-guided transbronchial needle aspiration for staging were enrolled. Maximum standardized uptake value (SUVmax), short axis diameter, LN-to-primary cancer ratio of SUVmax, and median Hounsfield unit (HU) based on CT histogram were correlated to histopathology. Of 271 nodes, 162 (59.8 %) were malignant. SUVmax, short axis diameter, and LPR of malignant LNs were higher than those of benign nodes. Among malignant LNs, 71.0 % had median HU between 25 and 45, while 78.9 % of benign LNs had values <25 HU or >45 HU. Using a cutoff value of 4.0, SUVmax showed the highest diagnostic ability for detecting malignant LNs with a specificity of 94.5 %, but showing a sensitivity of 70.4 %. Using additional density criteria (median HU 25-45) in LNs with 2.0< SUVmax ≤4.0, the sensitivity increased to 88.3 % with the specificity of 82.6 %. LN density is useful for the characterization of LNs with mild {sup 18}F-FDG uptake. The risk of mediastinal LN metastasis in NSCLC patients could be further stratified using both {sup 18}F-FDG uptake and LN density. (orig.)

  14. Feasibility study of utilizing jatropha curcas oil as bio-diesel in an oil firing burner system

    Science.gov (United States)

    Shaiful, A. I. M.; Jaafar, M. N. Mohd; Sahar, A. M.

    2017-09-01

    Jatropha oil derived from the Jatropha Curcas Linnaeus is one of the high potential plants to be use as bio-diesel. The purpose of this research is to carry out a feasibility study of using jatropha oil as bio-diesel on oil firing burner system. Like other bio-diesels, jatropha oil can also be used in any combustion engine and the performance and emissions such as NOx, SO2, CO and CO2 as well as unburned hydocarbon (UHC) from the engine will vary depending on the bio-diesel blends. The properties of Conventional Diesel Fuel (CDF) obtained will be used as baseline and the jatropha oil properties will be compared as well as other bio-diesels. From several researches, the properties of jatropha oil was found to be quite similar with other bio-diesel such as palm oil, neem, keranja and pongamia bio-diesel and complying with the ASTM standard for bio-diesel. Still, there are factors and issues concerning the use of jatropha oil such as technology, economy, legislation and resource. Plus, there several challenges to the growth of bio-diesel industry development since the world right now do not totally depend on the bio-diesel.

  15. Evaluating measurements of carbon dioxide emissions using a precision source--A natural gas burner.

    Science.gov (United States)

    Bryant, Rodney; Bundy, Matthew; Zong, Ruowen

    2015-07-01

    A natural gas burner has been used as a precise and accurate source for generating large quantities of carbon dioxide (CO2) to evaluate emissions measurements at near-industrial scale. Two methods for determining carbon dioxide emissions from stationary sources are considered here: predicting emissions based on fuel consumption measurements-predicted emissions measurements, and direct measurement of emissions quantities in the flue gas-direct emissions measurements. Uncertainty for the predicted emissions measurement was estimated at less than 1%. Uncertainty estimates for the direct emissions measurement of carbon dioxide were on the order of ±4%. The relative difference between the direct emissions measurements and the predicted emissions measurements was within the range of the measurement uncertainty, therefore demonstrating good agreement. The study demonstrates how independent methods are used to validate source emissions measurements, while also demonstrating how a fire research facility can be used as a precision test-bed to evaluate and improve carbon dioxide emissions measurements from stationary sources. Fossil-fuel-consuming stationary sources such as electric power plants and industrial facilities account for more than half of the CO2 emissions in the United States. Therefore, accurate emissions measurements from these sources are critical for evaluating efforts to reduce greenhouse gas emissions. This study demonstrates how a surrogate for a stationary source, a fire research facility, can be used to evaluate the accuracy of measurements of CO2 emissions.

  16. Fast-solving thermally thick model of biomass particles embedded in a CFD code for the simulation of fixed-bed burners

    International Nuclear Information System (INIS)

    Gómez, M.A.; Porteiro, J.; Patiño, D.; Míguez, J.L.

    2015-01-01

    Highlights: • A thermally thick treatment is used to simulate of fuel the thermal conversion of solid biomass. • A dynamic subgrid scale is used to model the advance of reactive fronts inside the particle. • Efficient solution algorithms are applied to calculate the temperatures and volume of the internal layers. • Several tests were simulated and compared with experimental data. - Abstract: The thermally thick treatment of fuel particles during the thermal conversion of solid biomass is required to consider the internal gradients of temperature and composition and the overlapping of the existing biomass combustion stages. Due to the implied mixture of scales, the balance between model resolution and computational efficiency is an important limitation in the simulation of beds with large numbers of particles. In this study, a subgrid-scale model is applied to consider the intraparticle gradients, the interactions with other particles and the gas phase using a Euler–Euler CFD framework. Numerical heat transfer and mass conservation equations are formulated on a subparticle scale to obtain a system of linear equations that can be used to resolve the temperature and position of the reacting front inside the characteristic particle of each cell. To simulate the entire system, this modelling is combined with other submodels of the gas phase, the bed reaction and the interactions. The performance of the new model is tested using published experimental results for the particle and the bed. Similar temperatures are obtained in the particle-alone tests. Although the mass consumption rates tend to be underpredicted during the drying stage, they are subsequently compensated. In addition, an experimental batch-loaded pellet burner was simulated and tested with different air mass fluxes, in which the experimental ignition rates and temperatures are employed to compare the thermally thick model with the thermally thin model that was previously developed by the authors

  17. The energetic performance of a novel hybrid solar thermal and chemical looping combustion plant

    International Nuclear Information System (INIS)

    Jafarian, Mehdi; Arjomandi, Maziar; Nathan, Graham J.

    2014-01-01

    Highlights: • A hybrid solar chemical looping combustion power cycle is reported. • The cycle is studied for two configurations, with and without an after-burner. • The oxygen carrier particles are used as storage medium for solar thermal energy. • Total solar shares of 41.4% and 60% are achieved with and without the after-burner. • Efficiencies of 50% and 44.0% are achieved with and without the after-burner. - Abstract: The overall energetic performance of a gas turbine combined cycle powered by a hybrid cycle between a solar thermal and a chemical looping combustion (CLC) system firing methane is reported for two configurations. In one case, the outlet from the air reactor is fed directly to a gas turbine, while in the other an after-burner, also firing methane, is added to increase the gas turbine inlet temperature. The cycle is simulated using Aspen Plus software for the average diurnal profile of normal irradiance for Port Augusta, South Australia. The first law efficiency, total solar absorption efficiency, average and peak fractional power boosts, total solar share, net solar to electrical efficiency, fraction of pressurised CO 2 , incremental CO 2 avoidance and the exergy efficiency for both cycles are reported. The calculations predict a first law efficiency of 50.0% for the cycle employing an after-burner, compared with 44.0% for that without the after-burner. However, this is achieved at the cost of decreasing the solar share from 60.0%, without the after-burner, to 41.4% with it. Also reported is the sensitivity analysis of performance to variations in key operating parameters. The sensitivity analysis shows that further improvements to the performance of the cycle are possible

  18. Impact of lymph node burden on survival of high-risk prostate cancer patients following radical prostatectomy and pelvic lymph node dissection

    Directory of Open Access Journals (Sweden)

    Lisa Moris

    2016-12-01

    Full Text Available Aim: To determine the impact of the extent of lymph node invasion (LNI, on long-term oncological outcomes after radical prostatectomy (RP. Material and methods: In this retrospective study we examined the data of 1249 high-risk, non-metastatic PCa patients treated with RP and pelvic lymph node dissection (PLND between 1989 and 2011 at 8 different tertiary institutions. We fitted univariate and multivariate cox models to assess independent predictors of cancer specific survival (CSS and overall survival (OS. The number of positive LN was dichotomized according to the most informative cut-off predicting CSS. Kaplan-Meier curves assessed CSS and OS rates. Only patients with at least 10 LNs removed at PLND were included. This cut-off was chosen as a surrogate for a well performed PNLD.Results: Mean age was 65 years (median: 66, IQR 60-70. Positive surgical margins were present in 53.7% (n=671. Final Gleason score was 2-6 in 12.7% (n=158, 7 in 52% (n=649 and 8-10 in 35.4% (n=442. The median number of LNs removed during PLND was 15 (IQR 12-17. Of all patients, 1128 (90.3% had 0-3 positive LNs, while 126 (9.7% had ≥4 positive LNs. Patients with 0-3 positive LNs had significantly better CSS outcome at 10-year follow-up compared to patients with ≥4 positive LNs (87% vs. 50%; p < 0.0001. Similar results were obtained for OS, with a 72% vs. 37% (p <0.0001 survival at 10 years for patients with 0-3 vs. ≥4 positive LNs, respectively. At multivariate analysis, final Gleason score 8-10, salvage ADT therapy and ≥4 (vs <4 positive LNs were predictors of worse CSS and OS. Pathological stage pT4 was an additional predictor of worse CSS. Conclusions: Four or more positive LNs, pathological stage pT4 and final Gleason score 8-10 represent independent predictors for worse CSS in patients with high-risk PCa. Primary tumor biology remains a strong driver of tumor progression and patients having ≥4 positive LNs could be considered an enriched patient group in

  19. Evaluating Employability Skills: Employer and Student Perceptions

    Science.gov (United States)

    Saunders, Venetia; Zuzel, Katherine

    2010-01-01

    Graduate employability is a key issue for Higher Education. In this two-part study student employability skills have been evaluated from the perspective of sandwich students and graduates in biomolecular science, and their employers. A strong correlation was found between employer and sandwich student/graduate perceptions of the relative…

  20. Fuel effects on the stability of turbulent flames with compositionally inhomogeneous inlets

    KAUST Repository

    Guiberti, T. F.; Juddoo, M.; Lacoste, Deanna; Dunn, M. J.; Roberts, William L.; Masri, A. R.

    2016-01-01

    This paper reports an analysis of the influence of fuels on the stabilization of turbulent piloted jet flames with inhomogeneous inlets. The burner is identical to that used earlier by the Sydney Group and employs two concentric tubes within

  1. Infra-red divergences and Regge behaviour in QCD

    International Nuclear Information System (INIS)

    Jaroszewicz, T.

    1980-01-01

    We analyze high energy behaviour of multi-gluon exchange amplitudes in the leading-lns approximation in perturbation theory. Working in the Coulomb gauge and employing Ward identities we derive an integral equation for the n-gluon system in the exchange channel. We find that the Regge behaviour is associated with exponentiation of leading infrared divergences, and the position of the j-plane singularities is determined by the colour quantum numbers of the exchanged system. (author)

  2. Number of Lymph Nodes Removed and Survival after Gastric Cancer Resection: An Analysis from the US Gastric Cancer Collaborative.

    Science.gov (United States)

    Gholami, Sepideh; Janson, Lucas; Worhunsky, David J; Tran, Thuy B; Squires, Malcolm Hart; Jin, Linda X; Spolverato, Gaya; Votanopoulos, Konstantinos I; Schmidt, Carl; Weber, Sharon M; Bloomston, Mark; Cho, Clifford S; Levine, Edward A; Fields, Ryan C; Pawlik, Timothy M; Maithel, Shishir K; Efron, Bradley; Norton, Jeffrey A; Poultsides, George A

    2015-08-01

    Examination of at least 16 lymph nodes (LNs) has been traditionally recommended during gastric adenocarcinoma resection to optimize staging, but the impact of this strategy on survival is uncertain. Because recent randomized trials have demonstrated a therapeutic benefit from extended lymphadenectomy, we sought to investigate the impact of the number of LNs removed on prognosis after gastric adenocarcinoma resection. We analyzed patients who underwent gastrectomy for gastric adenocarcinoma from 2000 to 2012, at 7 US academic institutions. Patients with M1 disease or R2 resections were excluded. Disease-specific survival (DSS) was calculated using the Kaplan-Meier method and compared using log-rank and Cox regression analyses. Of 742 patients, 257 (35%) had 7 to 15 LNs removed and 485 (65%) had ≥16 LNs removed. Disease-specific survival was not significantly longer after removal of ≥16 vs 7 to 15 LNs (10-year survival, 55% vs 47%, respectively; p = 0.53) for the entire cohort, but was significantly improved in the subset of patients with stage IA to IIIA (10-year survival, 74% vs 57%, respectively; p = 0.018) or N0-2 disease (72% vs 55%, respectively; p = 0.023). Similarly, for patients who were classified to more likely be "true N0-2," based on frequentist analysis incorporating both the number of positive and of total LNs removed, the hazard ratio for disease-related death (adjusted for T stage, R status, grade, receipt of neoadjuvant and adjuvant therapy, and institution) significantly decreased as the number of LNs removed increased. The number of LNs removed during gastrectomy for adenocarcinoma appears itself to have prognostic implications for long-term survival. Copyright © 2015 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  3. Calculation of ex-core detector weighting functions for a sodium-cooled tru burner mockup using MCNP5

    International Nuclear Information System (INIS)

    Pham Nhu Viet Ha; Min Jae Lee; Sunghwan Yun; Sang Ji Kim

    2015-01-01

    Power regulation systems of fast reactors are based on the signals of excore detectors. The excore detector weighting functions, which establish correspondence between the core power distribution and detector signal, are very useful for detector response analyses, e.g., in rod drop experiments. This paper presents the calculation of the weighting functions for a TRU burner mockup of the Korean Prototype Generation-IV Sodium-cooled Fast Reactor (named BFS-76-1A) using the MCNP5 multi-group adjoint capability. For generation of the weighting functions, all fuel assemblies were considered and each of them was divided into ten horizontal layers. Then the weighting functions for individual fuel assembly horizontal layers, the assembly weighting functions, and the shape annealing functions at RCP (Reactor Critical Point) and at conditions under which a control rod group was fully inserted into the core while other control rods at RCP were determined and evaluated. The results indicate that the weighting functions can be considered relatively insensitive to the control rods position during the rod drop experiments and therefore those weighting values at RCP can be applied to the dynamic rod worth simulation for the BFS-76-1A. (author)

  4. The cross section sensitivity of the minor actinides on a lead-bismuth cooled accelerator-driven burner system

    International Nuclear Information System (INIS)

    Gil, Choong-Sup; Kim, Jung-Do; Chang, Jonghwa

    2002-01-01

    In order to validate the detailed sensitivity of each minor actinide datum in ENDF/B-VI Release 6, JEF-2.2 and JENDL-3.2 on an accelerator-driven minor actinide burner benchmark system, a lead-bismuth cooled sub-critical system was analyzed. The impacts on the system by the ten minor actinides were compared. The k eff values and reaction rates were calculated by exchanging the data sets of each minor actinide from ENDF/B-VI.6 to JEF-2.2 or JENDL-3.2. At the equilibrium core, the k eff differences from ENDF/B-VI.6 by the ten minor actinides can cause more than 5,500 pcm for JEF-2.2 and 3,500 pcm for JENDL-3.2. The fission reaction rates of 242m Am and 243 Cm with ENDF/B-VI.6 show differences of more than 15% from those with JEF-2.2 and JENDL-3.2. 241 Am, 243 Am and 245 Cm in JEF-2.2 and americium isotope data and 245 Cm in JENDL-3.2 are sensitive to the fission spectrum. (author)

  5. Deposit formation by 20 % (V/V) FAME fuels in premix burner systems; Ablagerungsbildung durch 20% (V/V) FAME-Brennstoffe in Vormischbrennersystemen

    Energy Technology Data Exchange (ETDEWEB)

    Jaschinski, Christian; Rheinberg, Oliver van [OWI Oel-Waerme-Institut GmbH, Aachen (Germany); RWTH Aachen (Germany). An-Institut

    2012-09-15

    In the domestic heating market the development and use of fuels with an increasing share of biogenic or alternative fuels is propagated. Due to the fact, that modern fuel oil burner feature a complex carburation techniques and combustion, changes on the fuel properties and composition can lead to increased emissions or deposit formation therein. Furthermore, the different fuel properties may result in decreased storage stability, which has to be evaluated before introducing them into the market. The scope of the project was to investigate the performance of low-sulfur domestic heating oil (DHO) with up to 20 % v/v FAME on the storage stability and on the use in oil-fired heating systems. The project was split into two major parts. The first part covered a two-year storage of the fuels including sampling and analysis of the fuels every half year. The analysis was conducted according to DIN 51603-1 for the pure DHO and according to DIN SPEC 51603-6 for the blends. It has been shown, that low sulphur domestic heating oil with up to 20 % (V/V) of FAME after two years of storage fits the parameter of the corresponding standards. Furthermore, a new testing method, called 'DGMK-714' derived from the PetroOxy-test (EN 16091) has been defined. With this method for the determination of oxidation stability the fuels can be characterized being comparable to the standardized testing methods of modified Rancimat or PetroOxy. The higher sample volume of the method allows further analysis of the fuel sample after testing for characterization of the fuels. The second part of the project investigated the deposit formation tendencies of the fuels in an idealized testing apparatus and in three different kinds of oil burners. Using the idealized testing apparatus proved an increased tendency of deposit formation during evaporation for an increasing FAME content. However, this tendency could not be observed in the three commercial oil-fired heating systems. A precise fuel

  6. Preoperative computed tomography of the chest in lung cancer patients: the predictive value of calcified lymph nodes for the perioperative outcomes of video-assisted thoracoscopic surgery lobectomy

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Kwang Nam; Lee, Youkyung; Wi, Jae Yeon [Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Department of Radiology, Seoul (Korea, Republic of); Moon, Hyeon-Jong; Sung, Yong Won [Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Department of Cardiothoracic Surgery, Seoul (Korea, Republic of)

    2013-12-15

    To determine the predictive value of identifying calcified lymph nodes (LNs) for the perioperative outcomes of video-assisted thoracoscopic surgery (VATS). Fifty-six consecutive patients who underwent VATS lobectomy for lung cancer were included. We evaluated the number and location of calcified LNs on computed tomography (CT). We investigated clinical parameters, including percentage forced expiratory volume in 1 s (FEV{sub 1}%), surgery duration, chest tube indwelling duration, and length of hospital stay. We performed linear regression analysis and multiple comparisons of perioperative outcomes. Mean number of calcified LNs per patient was 0.9 (range, 0-6), mostly located in the hilar-interlobar zone (43.8 %). For surgery duration (mean, 5.0 h), FEV{sub 1}% and emphysema severity were independent predictors (P = 0.010 and 0.003, respectively). The number of calcified LNs was an independent predictor for chest tube indwelling duration (P = 0.030) and length of hospital stay (P = 0.046). Mean duration of chest tube indwelling and hospital stay was 8.8 days and 12.7 days in no calcified LN group; 9.2 and 13.2 in 1 calcified LN group; 12.8 and 19.7 in {>=}2 calcified LNs group, respectively. The presence of calcified LNs on CT can help predict more complicated perioperative course following VATS lobectomy. (orig.)

  7. A dural lymphatic vascular system that drains brain interstitial fluid and macromolecules.

    Science.gov (United States)

    Aspelund, Aleksanteri; Antila, Salli; Proulx, Steven T; Karlsen, Tine Veronica; Karaman, Sinem; Detmar, Michael; Wiig, Helge; Alitalo, Kari

    2015-06-29

    The central nervous system (CNS) is considered an organ devoid of lymphatic vasculature. Yet, part of the cerebrospinal fluid (CSF) drains into the cervical lymph nodes (LNs). The mechanism of CSF entry into the LNs has been unclear. Here we report the surprising finding of a lymphatic vessel network in the dura mater of the mouse brain. We show that dural lymphatic vessels absorb CSF from the adjacent subarachnoid space and brain interstitial fluid (ISF) via the glymphatic system. Dural lymphatic vessels transport fluid into deep cervical LNs (dcLNs) via foramina at the base of the skull. In a transgenic mouse model expressing a VEGF-C/D trap and displaying complete aplasia of the dural lymphatic vessels, macromolecule clearance from the brain was attenuated and transport from the subarachnoid space into dcLNs was abrogated. Surprisingly, brain ISF pressure and water content were unaffected. Overall, these findings indicate that the mechanism of CSF flow into the dcLNs is directly via an adjacent dural lymphatic network, which may be important for the clearance of macromolecules from the brain. Importantly, these results call for a reexamination of the role of the lymphatic system in CNS physiology and disease. © 2015 Aspelund et al.

  8. Enhanced Antibody Responses in a Novel NOG Transgenic Mouse with Restored Lymph Node Organogenesis

    Directory of Open Access Journals (Sweden)

    Takeshi Takahashi

    2018-01-01

    Full Text Available Lymph nodes (LNs are at the center of adaptive immune responses. Various exogenous substances are transported into LNs and a series of immune responses ensue after recognition by antigen–specific lymphocytes. Although humanized mice have been used to reconstitute the human immune system, most lack LNs due to deficiency of the interleukin (IL-2Rγ gene (cytokine common γ chain, γc. In this study, we established a transgenic strain, NOG-pRORγt-γc, in the NOD/shi-scid-IL-2Rγnull (NOG background, in which the γc gene was expressed in a lymph-tissue inducer (LTi lineage by the endogenous promoter of RORγt. In this strain, LN organogenesis was normalized and the number of human T cells substantially increased in the periphery after reconstitution of the human immune system by human hematopoietic stem cell transplantation. The distribution of human T cells differed between NOG-pRORγt-γc Tg and NOG-non Tg mice. About 40% of human T cells resided in LNs, primarily the mesenteric LNs. The LN-complemented humanized mice exhibited antigen-specific immunoglobulin G responses together and an increased number of IL-21+–producing CD4+ T cells in LNs. This novel mouse strain will facilitate recapitulation of human immune responses.

  9. Use of freeze-casting in advanced burner reactor fuel design

    Energy Technology Data Exchange (ETDEWEB)

    Lang, A. L.; Yablinsky, C. A.; Allen, T. R. [Dept. of Engineering Physics, Univ. of Wisconsin Madison, 1500 Engineering Drive, Madison, WI 53711 (United States); Burger, J.; Hunger, P. M.; Wegst, U. G. K. [Thayer School of Engineering, Dartmouth College, 8000 Cummings Hall, Hanover, NH 03755 (United States)

    2012-07-01

    This paper will detail the modeling of a fast reactor with fuel pins created using a freeze-casting process. Freeze-casting is a method of creating an inert scaffold within a fuel pin. The scaffold is created using a directional solidification process and results in open porosity for emplacement of fuel, with pores ranging in size from 300 microns to 500 microns in diameter. These pores allow multiple fuel types and enrichments to be loaded into one fuel pin. Also, each pore could be filled with varying amounts of fuel to allow for the specific volume of fission gases created by that fuel type. Currently fast reactors, including advanced burner reactors (ABR's), are not economically feasible due to the high cost of operating the reactors and of reprocessing the fuel. However, if the fuel could be very precisely placed, such as within a freeze-cast scaffold, this could increase fuel performance and result in a valid design with a much lower cost per megawatt. In addition to competitive costs, freeze-cast fuel would also allow for selective breeding or burning of actinides within specific locations in fast reactors. For example, fast flux peak locations could be utilized on a minute scale to target specific actinides for transmutation. Freeze-cast fuel is extremely flexible and has great potential in a variety of applications. This paper performs initial modeling of freeze-cast fuel, with the generic fast reactor parameters for this model based on EBR-II. The core has an assumed power of 62.5 MWt. The neutronics code used was Monte Carlo N-Particle (MCNP5) transport code. Uniform pore sizes were used in increments of 100 microns. Two different freeze-cast scaffold materials were used: ceramic (MgO-ZrO{sub 2}) and steel (SS316L). Separate models were needed for each material because the freeze-cast ceramic and metal scaffolds have different structural characteristics and overall porosities. Basic criticality results were compiled for the various models

  10. A Population-based Study on Lymph Node Retrieval in Patients with Esophageal Cancer: Results from the Dutch Upper Gastrointestinal Cancer Audit.

    Science.gov (United States)

    van der Werf, L R; Dikken, J L; van Berge Henegouwen, M I; Lemmens, V E P P; Nieuwenhuijzen, G A P; Wijnhoven, B P L

    2018-05-01

    For esophageal cancer, the number of retrieved lymph nodes (LNs) is often used as a quality indicator. The aim of this study is to analyze the number of retrieved LNs in The Netherlands, assess factors associated with LN yield, and explore the association with short-term outcomes. This is a population-based study on lymph node retrieval in patients with esophageal cancer, presenting results from the Dutch Upper Gastrointestinal Cancer Audit. For this retrospective national cohort study, patients with esophageal carcinoma who underwent esophagectomy between 2011 and 2016 were included. The primary outcome was the number of retrieved LNs. Univariable and multivariable regression analyses were used to test for association with ≥ 15 LNs. 3970 patients were included. Between 2011 and 2016, the median number of LNs increased from 15 to 20. Factors independently associated with ≥ 15 LNs were: 0-10 kg preoperative weight loss (versus: unknown weight loss, odds ratio [95% confidence interval]: 0.71 [0.57-0.88]), Charlson score 0 (versus: Charlson score 2: 0.76 [0.63-0.92]), cN2 category (reference: cN0, 1.32 [1.05-1.65]), no neoadjuvant therapy and neoadjuvant chemotherapy (reference: neoadjuvant chemoradiotherapy, 1.73 [1.29-2.32] and 2.15 [1.54-3.01]), minimally invasive transthoracic (reference: open transthoracic, 1.46 [1.15-1.85]), open transthoracic (versus open and minimally invasive transhiatal, 0.29 [0.23-0.36] and 0.43 [0.32-0.59]), hospital volume of 26-50 or > 50 resections/year (reference: 0-25, 1.94 [1.55-2.42] and 3.01 [2.36-3.83]), and year of surgery [reference: 2011, odds ratios (ORs) 1.48, 1.53, 2.28, 2.44, 2.54]. There was no association of ≥ 15 LNs with short-term outcomes. The number of LNs retrieved increased between 2011 and 2016. Weight loss, Charlson score, cN category, neoadjuvant therapy, surgical approach, year of resection, and hospital volume were all associated with increased LN yield. Retrieval of ≥ 15 LNs was not associated

  11. Laboratory for Nuclear Science. High Energy Physics Program

    Energy Technology Data Exchange (ETDEWEB)

    Milner, Richard [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2014-07-30

    High energy and nuclear physics research at MIT is conducted within the Laboratory for Nuclear Science (LNS). Almost half of the faculty in the MIT Physics Department carry out research in LNS at the theoretical and experimental frontiers of subatomic physics. Since 2004, the U.S. Department of Energy has funded the high energy physics research program through grant DE-FG02-05ER41360 (other grants and cooperative agreements provided decades of support prior to 2004). The Director of LNS serves as PI. The grant supports the research of four groups within LNS as “tasks” within the umbrella grant. Brief descriptions of each group are given here. A more detailed report from each task follows in later sections. Although grant DE-FG02-05ER41360 has ended, DOE continues to fund LNS high energy physics research through five separate grants (a research grant for each of the four groups, as well as a grant for AMS Operations). We are pleased to continue this longstanding partnership.

  12. Efficiency of B-mode Ultrasound and Strain Elastography in Differentiating Between Benign and Malignant Cervical Lymph Nodes.

    Science.gov (United States)

    Turgut, Eser; Celenk, Cetin; Tanrivermis Sayit, Asli; Bekci, Tumay; Gunbey, Hediye Pinar; Aslan, Kerim

    2017-09-01

    The purpose of this study was to evaluate the diagnostic accuracy and efficiency of ultrasonography (US), especially when combined with strain elastography (SE), in differentiating between benign and malignant cervical lymph nodes (LNs). Forty-one LNs were examined by B-mode US, power Doppler US, and SE. The following imaging features were analyzed: shape, echogenicity, echogenic hilum, calcification, intranodal vascular pattern, elasticity scores (5 categories), and strain ratio. The average strain ratio was calculated as the mean strain of the adjacent sternocleidomastoid muscle divided by the mean strain of the target LN. The results of the US and SE features were compared with the histopathologic findings. The imaging features that were significantly associated with malignant LNs were an increased short-to-long axis diameter ratio, abnormal or absence of hilum, microcalcification, type 2-3-4 vascularity, 3-4-5 elasticity scores, and a high level of strain ratio (P benign and malignant LNs. Strain elastography is useful in differentiating between benign and malignant cervical LNs, thereby informing decisions to perform a biopsy and/or surgery, and facilitating follow-up.

  13. The Employer Perspective on Sustainable Employability in the Construction Industry

    NARCIS (Netherlands)

    Tonnon, Susanne C; van der Veen, Rozan; Westerman, Marjan J; Robroek, Suzan J W; van der Ploeg, Hidde P; Van Der Beek, Allard J.; Proper, Karin I.

    OBJECTIVE: To determine the measures employers in the construction industry take to promote sustainable employability, the barriers and facilitators that influence implementation and employer needs. METHODS: Questionnaire among 499 employers and interviews with 17 employers. RESULTS: Employers

  14. Analysis of the current–voltage curves and saturation currents in burner-stabilised premixed flames with detailed ion chemistry and transport models

    KAUST Repository

    Belhi, Memdouh

    2018-05-22

    Current-voltage, or i–V, curves are used in combustion to characterise the ionic structure of flames. The objective of this paper is to develop a detailed modelling framework for the quantitative prediction of the i–V curves in methane/air flames. Ion and electron transport coefficients were described using methods appropriate for charged species interactions. An ionic reaction mechanism involving cations, anions and free electrons was used, together with up-to-date rate coefficients and thermodynamic data. Because of the important role of neutral species in the ion production process, its prediction by the detailed AramcoMech 1.4 mechanism was optimised by using available experimental measurements. Model predictions were evaluated by comparing to i–V curves measured in atmospheric-pressure, premixed, burner-stabilised flames. A detailed evaluation of the reliability of ion kinetic and transport parameters adopted was performed. The model provides good quantitative agreement with experimental data for various conditions.

  15. Is Self-Employment Really a Bad Experience? The Effects of Previous Self-Employment on Subsequent Wage-Employment Wages

    DEFF Research Database (Denmark)

    Kaiser, Ulrich; Malchow-Møller, Nikolaj

    2011-01-01

    of self-employment is associated with lower hourly wages compared to workers who were consecutively wage-employed. We also show, however, that this effect disappears—and even becomes positive in some settings—for formerly self-employed who find dependent employment in the same sector as their self......-employment sector. Hence, the on average negative effect of self-employment is rather caused by sector switching than by the self-employment experience per se. Moreover, formerly self-employed who either enjoyed a high income or hired at least one worker during their self-employment spell receive wages...... in subsequent dependent employment that are at least as high as for individuals who have been consecutively wage-employed....

  16. Time evolution of propagating nonpremixed flames in a counterflow, annular slot burner under AC electric fields

    KAUST Repository

    Tran, Vu Manh

    2016-06-19

    The mechanism behind improved flame propagation speeds under electric fields is not yet fully understood. Although evidence supports that ion movements cause ionic wind, how this wind affects flame propagation has not been addressed. Here, we apply alternating current electric fields to a gap between the upper and lower parts of a counterflow, annular slot burner and present the characteristics of the propagating nonpremixed edge-flames produced. Contrary to many other previous studies, flame displacement speed decreased with applied AC voltage, and, depending on the applied AC frequency, the trailing flame body took on an oscillatory wavy motion. When flame displacement speeds were corrected using measured unburned flow velocities, we found no significant difference in flame propagation speeds, indicating no thermal or chemical effects by electric fields on the burning velocity. Thus, we conclude that the generation of bidirectional ionic wind is responsible for the impact of electric fields on flames and that an interaction between this bidirectional ionic wind and the flame parameters creates visible and/or measurable phenomenological effects. We also explain that the presence of trailing flame bodies is a dynamic response to an electric body force on a reaction zone, an area that can be considered to have a net positively charged volume. In addition, we characterize the wavy motion of the transient flame as a relaxation time independent of mixture strength, strain rate, and Lewis number.

  17. Graduate Employability: A Conceptual Framework for Understanding Employers' Perceptions

    Science.gov (United States)

    Cai, Yuzhuo

    2013-01-01

    This study provides a conceptual framework for understanding what employers think about the value of graduates with similar educational credentials in the workplace (their employability), using insights from the new institutionalism. In this framework, the development of employers' beliefs about graduates' employability is broken into a number of…

  18. Employing Discourse: Universities and Graduate "Employability"

    Science.gov (United States)

    Boden, Rebecca; Nedeva, Maria

    2010-01-01

    What constitutes graduate employability is discursively framed. In this paper we argue that whilst universities in the UK have long had an involvement in producing useful and productive citizens, the ongoing neoliberalisation of higher education has engendered a discursive shift in definitions of employability. Traditionally, universities regarded…

  19. Acceptability of Supplementary Foods for Children with Moderate Acute Malnutrition and Feeding Behaviours During Home-Based Treatment

    DEFF Research Database (Denmark)

    Iuel-Brockdorff, Ann-Sophie Julie D

    Background Moderate acute malnutrition (MAM) affects around 33 million children and is a major global health problem, causing increased morbidity and mortality and delayed cognitive development. Despite the development of lipid-based nutrient supplement (LNS) and enhanced versions of corn-soy blend...... children receiving CBS had leftovers compared to children receiving LNS. Similar supplementary foods used for the prevention and treatment of malnutrition were generally well appreciated in the study context, although LNS was considered different from local foods and to a higher extend associated...

  20. Cutting edge SRU control : improved environmental compliance with Jacobs advanced burner control+ (ABC+)

    Energy Technology Data Exchange (ETDEWEB)

    Molenaar, G. [Jacobs Canada Inc., Calgary, AB (Canada); Henning, A.; Kobussen, S. [Jacobs Nederland BV, Hoogvliet (Netherlands)

    2009-07-01

    Oil sands bitumen contains approximately 4 to 5 per cent sulphur by weight and the bitumen is upgraded to produce lighter fractions. During coking the bitumen is heated and cracked into lighter molecules and a mixture of kerosene, naphtha and gas oil is recovered via fractionation. Then, the vapors leaving the fractionator are processed through hydrodesulphurization, followed by removal by amine based sweetening units. The acid gas from the ASUs is sent to the sulphur recovery units (SRUs) where most of the sulphur is recovered as elemental sulphur. The oil sands industry faces many challenges with respect to environmental impact, energy use and greenhouse gas emissions including the recovery of sulphur and minimizing hydrogen sulfide (H{sub 2}S) and sulphur dioxide (SO{sub 2}) emissions from the oil sands production facilities. In order to improve the SRU control response to acid gas feed variations, Jacobs Comprimo Sulphur Solutions implemented advanced burner control+ (ABC+) at Suncor's Simonette Gas Plant's SRU in northern Alberta. This control system used an acid gas feed analyzer and dynamic algorithms to control the combustion air to the reaction furnace. The analyzer measures H{sub 2}S, total hydrocarbons, carbon dioxide (CO{sub 2}) and water (H{sub 2}O) accurately and quickly, which is important for having effective and fast air-to-acid gas ratio control. The paper provided background information on the Suncor Simonette Gas Plant and discussed ABC+ versus conventional control. An overview of the simplified ABC and ABC+ systems was then illustrated and presented. The ABB multiwave process photometer was also explained. Last, a dynamic simulation of the potential benefits of ABC+ was discussed and the ABC+ benefits for oil sands were presented. It was concluded that ABC+ provides improved SRU performance, reduced SO{sub 2} emissions and violations, and reduced flaring. 1 tab., 3 figs.

  1. Flat-flame burner studies of pulverized-coal combustion. Experimental results on char reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Peck, R.E.; Shi, L.

    1996-12-01

    Structure of laminar, premixed pulverized-coal flames in a 1-D reactor has been studied with emphasis on char reactivity. A 1.1-meter-long tube furnace accommodated high-temperature environments and long residence times for the laminar flames produced by a flat-flame, coal-dust burner. Experiments were conducted at different operating conditions (fuel type/size, fuel-air ratio). Measurements included solid sample composition, major gas species and hydrocarbon species concentrations, and gas- and particle-phase line-of-sight temperatures at different axial locations in flames. Degree of char burnout increased with coal volatiles content and decreased with coal particle size. Combustion in furnace was in oxidizer-deficient environment and higher burnout was achieved as the fuel-air ratio neared stoichiometric. For 0-45 {mu}m particles most of the fixed carbon mass loss occurred within 5 cm of the furnace inlet, and char reaction was slow downstream due to low oxidizer concentrations. Fixed carbon consumption of the 45-90 {mu}m particles generally was slower than for the small particles. About 40%-80% of the fixed carbon was oxidized in the furnace. Primary volatiles mass loss occurred within the first 4.5 cm, and more than 90% of the volatiles were consumed in the flames. The flames stabilized in the furnace produced less CH{sub 4} and H{sub 2} in the burnt gas than similar unconfined flames. NO concentrations were found to decrease along the furnace and to increase with decreasing fuel/air ratio. Temperature measurement results showed that gas-phase temperatures were higher than solid-phase temperatures. Temperatures generally decreased with decreasing volatiles content and increased as the equivalence ratio approached one. The results can be used to interpret thermochemical processes occurring in pulverized-coal combustion. (au) 15 refs.

  2. Spray characteristics and liquid distribution of multi-hole effervescent atomisers for industrial burners

    International Nuclear Information System (INIS)

    Jedelský, Jan; Jícha, Miroslav

    2016-01-01

    Highlights: • The multi-hole (mh) spray morphology is very similar to that of single-hole nozzles. • Unsteady spray was found at low pressure and low gas-to-liquid-ratio (GLR) values. • Cone angle variation in mh spray with pressure and GLR depends on the exit nozzles angle. • A liquid–gas gravitational separation in horizontal atomiser operation was observed. • It causes up to 70% fuel supply variance into exit holes depending on design and regime. - Graphical Abstract: - Abstract: The present paper provides an experimental study and optimisation of multi-hole effervescent atomisers for industrial burners using oil-based fossil, bio- or waste fuels with prospects of emission reduction. Several multi-hole nozzles were designed based on our previous work. We probed the spray quality by phase-Doppler anemometry. 3-D plots of Sauter mean diameter and mean droplet velocity demonstrate their spatial distribution within the spray. The effect of geometrical and operational factors on the spray is discussed. Droplet size–velocity correlations as well as the size and velocity distributions are presented, and differences are found against other investigations. A spray macrostructure is photographically observed and spray cone angles of the multi-hole nozzles are analysed. An internal two-phase flow is estimated using the Baker's map for horizontal two-phase flow. Our previous two-phase flow visualisations suggested a liquid–gas gravitational separation when the multi-hole atomiser operated horizontally. This issue is addressed here; the results of spray heterogeneity measurements document that fuel flow rates through individual exit holes differ significantly. This difference spans between 0 and 70% depending on the nozzle design and flow regime. Effervescent sprays are unsteady under some operating conditions; spray unsteadiness was detected at low pressure and low gas-to-liquid-ratios.

  3. Limited Nesting Stress Alters Maternal Behavior and In Vivo Intestinal Permeability in Male Wistar Pup Rats.

    Directory of Open Access Journals (Sweden)

    Nabila Moussaoui

    Full Text Available A few studies indicate that limited nesting stress (LNS alters maternal behavior and the hypothalamic pituitary adrenal (HPA axis of dams and offspring in male Sprague Dawley rats. In the present study, we evaluated the impact of LNS on maternal behavior in Wistar rats, and on the HPA axis, glycemia and in vivo intestinal permeability of male and female offspring. Intestinal permeability is known to be elevated during the first week postnatally and influenced by glucocorticoids. Dams and neonatal litters were subjected to LNS or normal nesting conditions (control from days 2 to 10 postnatally. At day 10, blood was collected from pups for determination of glucose and plasma corticosterone by enzyme immunoassay and in vivo intestinal permeability by oral gavage of fluorescein isothiocyanate-dextran 4kDa. Dams exposed to LNS compared to control showed an increase in the percentage of time spent building a nest (118%, self-grooming (69%, and putting the pups back to the nest (167%. LNS male and female pups exhibited a reduction of body weight by 5% and 4%, adrenal weights/100g body weight by 17% and 18%, corticosterone plasma levels by 64% and 62% and blood glucose by 11% and 12% respectively compared to same sex control pups. In male LNS pups, intestinal permeability was increased by 2.7-fold while no change was observed in females compared to same sex control. There was no sex difference in any of the parameters in control pups except the body weight. These data indicate that Wistar dams subjected to LNS during the first postnatal week have an altered repertoire of maternal behaviors which affects the development of the HPA axis in both sexes and intestinal barrier function in male offspring.

  4. Responsive feeding and child interest in food vary when rural Malawian children are fed lipid-based nutrient supplements or local complementary food.

    Science.gov (United States)

    Flax, Valerie L; Mäkinen, Samppa; Ashorn, Ulla; Cheung, Yin Bun; Maleta, Kenneth; Ashorn, Per; Bentley, Margaret E

    2013-07-01

    Caregiver and child behaviours during feeding have been used to measure responsiveness, which has been recognised as important for child growth and development. The aims of this study were to understand how caregiver and child behaviours differ when feeding lipid-based nutrient supplements (LNS) vs. local complementary food and to detect associations between behaviours and child interest in food. Sixteen moderately underweight 6-17-month-old Malawian children receiving 50 g/day of supplementary LNS for 12 weeks were videotaped during LNS (n = 32) and local complementary feeding (n = 28) episodes. Behaviours were coded at the level of the intended bite (1674 total bites). The analysis used regression models adjusted for within-subject correlation. Caregivers were less likely to allow children to self-feed and more likely to use physical pressure during LNS vs. complementary food bites. Positive caregiver verbalization was infrequent and did not differ by type of food. Higher odds of accepting a bite were associated with the bite containing LNS, odds ratio (OR) 3.05; 90% confidence interval (CI) (1.98, 4.71), the child self-feeding, OR 5.70; 90% CI (2.77, 11.69), and positive caregiver verbalization, OR 2.46; 90% CI (1.26, 4.80), while lower odds of acceptance were associated with negative child verbalization during feeding, OR 0.27; 90% CI (0.17, 0.42). In this sample, caregivers used more responsive feeding practices during bites of local complementary food and were more controlling when feeding LNS. Responsive caregiver behaviours predicted child acceptance of food. These results could be used to design interventions in Malawi to improve responsive feeding practices in general and during LNS use. © 2011 John Wiley & Sons Ltd.

  5. Providing lipid-based nutrient supplements does not affect developmental milestones among Malawian children.

    Science.gov (United States)

    Mangani, Charles; Cheung, Yin Bun; Maleta, Kenneth; Phuka, John; Thakwalakwa, Chrissie; Dewey, Kathryn; Manary, Mark; Puumalainen, Taneli; Ashorn, Per

    2014-01-01

    To assess whether using lipid-based nutrient supplements (LNS) to complement the diets of infants and young children affected when they achieved selected developmental milestones. In rural Malawi, 840 6-month-old healthy infants were enrolled to a randomised trial. Control participants received no supplements, others were provided with milk-containing LNS, soy-containing LNS or corn-soy blend (CSB) for 12 months. Outcomes were the age at which they achieved key milestone: motor (walking with assistance, standing and walking alone, running), social (drinking from a cup and eating by themselves) and language (saying single comprehensible words and waving goodbye). The mean age at which the subjects walked with assistance was 42.5, 42.3, 42.7 and 43.2 weeks in the control, milk-LNS, soy-LNS and CSB groups, respectively (p = 0.748). There were also no significant differences in the mean age at standing alone (45.0, 44.9, 45.1 and 46.3 weeks), walking alone (54.6, 55.1, 55.3, 56.5 weeks), running (64.6, 63.7, 64.8, 65.9 weeks) or any other social or language milestones (each p > 0.10). The findings do not support a hypothesis that providing tested formulations and doses of micronutrient-fortified LNS or CSB would have an impact on when young children in rural Malawi achieved selected developmental milestones. ©2013 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  6. A laboratory investigation on the influence of adsorbed gases and particles from the exhaust of a kerosene burner on the evaporation rate of ice crystals and the ice nucleating ability of the exhaust particles

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, K; Mitra, S K; Pruppacher, H R [Johannes Gutenberg Univ., Mainz (Germany). Inst. fuer Physik der Atmosphaere

    1998-12-31

    Laboratory experiments are described during which the influence of the exhausts of a kerosene burner on microphysical processes were studied. In one experimental investigation the evaporation rates of polluted ice crystals were compared with the evaporation rates of pure ice crystals. During another experimental investigation the ice nucleating ability of the exhaust particles was studied. The results show that the evaporation rate of polluted ice crystals was significantly reduced and also that ice nucleation takes place between -20 and -38 deg C. (author) 7 refs.

  7. A laboratory investigation on the influence of adsorbed gases and particles from the exhaust of a kerosene burner on the evaporation rate of ice crystals and the ice nucleating ability of the exhaust particles

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, K.; Mitra, S.K.; Pruppacher, H.R. [Johannes Gutenberg Univ., Mainz (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    Laboratory experiments are described during which the influence of the exhausts of a kerosene burner on microphysical processes were studied. In one experimental investigation the evaporation rates of polluted ice crystals were compared with the evaporation rates of pure ice crystals. During another experimental investigation the ice nucleating ability of the exhaust particles was studied. The results show that the evaporation rate of polluted ice crystals was significantly reduced and also that ice nucleation takes place between -20 and -38 deg C. (author) 7 refs.

  8. 75 FR 3168 - Vocational Rehabilitation and Employment Program-Self-Employment

    Science.gov (United States)

    2010-01-20

    ... Employment Program--Self-Employment AGENCY: Department of Veterans Affairs. ACTION: Final rule. SUMMARY: This document amends the vocational rehabilitation and employment regulations of the Department of Veterans Affairs (VA) concerning self-employment for individuals with qualifying disabilities. We are making...

  9. Employment specialist competencies for supported employment programs

    NARCIS (Netherlands)

    Corbière, M.; Brouwers, E.P.M.; Lanctôt, N.; van Weeghel, J.

    2014-01-01

    Purpose Supported employment (SE) programs are evidence-based programs offered to people with severe mental illness to facilitate obtaining and keeping competitive work. However, significant variations in individuals’ vocational success may be partly explained by differences in their employment

  10. Breastfeeding and employment: an assessment of employer attitudes.

    Science.gov (United States)

    Libbus, M Kay; Bullock, Linda F C

    2002-08-01

    Both research and anecdotal reports suggest that maternal employment is associated with failure to initiate breastfeeding and early breastfeeding attrition. The objective of this study was to describe the experience with and attitudes toward breastfeeding of a sample of employers in a small Midwestern city in the United States. Based on an analysis of 85 mail-out questionnaires, we found that less than half of the employers had personal experience with breastfeeding. A large percentage of the sample, however, indicated that they would be willing to facilitate women who wished to breastfeed or express milk in the workplace. However, these employers also stated that they saw little value to their business of supporting breastfeeding in the work environment. Thus, enhancement of breastfeeding opportunity in the work environment may come as a result of public and employer education but, more likely, will require some type of directive from official sources.

  11. Advanced Fuel Cycle Economic Analysis of Symbiotic Light-Water Reactor and Fast Burner Reactor Systems

    Energy Technology Data Exchange (ETDEWEB)

    D. E. Shropshire

    2009-01-01

    The Advanced Fuel Cycle Economic Analysis of Symbiotic Light-Water Reactor and Fast Burner Reactor Systems, prepared to support the U.S. Advanced Fuel Cycle Initiative (AFCI) systems analysis, provides a technology-oriented baseline system cost comparison between the open fuel cycle and closed fuel cycle systems. The intent is to understand their overall cost trends, cost sensitivities, and trade-offs. This analysis also improves the AFCI Program’s understanding of the cost drivers that will determine nuclear power’s cost competitiveness vis-a-vis other baseload generation systems. The common reactor-related costs consist of capital, operating, and decontamination and decommissioning costs. Fuel cycle costs include front-end (pre-irradiation) and back-end (post-iradiation) costs, as well as costs specifically associated with fuel recycling. This analysis reveals that there are large cost uncertainties associated with all the fuel cycle strategies, and that overall systems (reactor plus fuel cycle) using a closed fuel cycle are about 10% more expensive in terms of electricity generation cost than open cycle systems. The study concludes that further U.S. and joint international-based design studies are needed to reduce the cost uncertainties with respect to fast reactor, fuel separation and fabrication, and waste disposition. The results of this work can help provide insight to the cost-related factors and conditions needed to keep nuclear energy (including closed fuel cycles) economically competitive in the U.S. and worldwide. These results may be updated over time based on new cost information, revised assumptions, and feedback received from additional reviews.

  12. Advanced Fuel Cycle Economic Analysis of Symbiotic Light-Water Reactor and Fast Burner Reactor Systems

    International Nuclear Information System (INIS)

    Shropshire, D.E.

    2009-01-01

    The Advanced Fuel Cycle Economic Analysis of Symbiotic Light-Water Reactor and Fast Burner Reactor Systems, prepared to support the U.S. Advanced Fuel Cycle Initiative (AFCI) systems analysis, provides a technology-oriented baseline system cost comparison between the open fuel cycle and closed fuel cycle systems. The intent is to understand their overall cost trends, cost sensitivities, and trade-offs. This analysis also improves the AFCI Program's understanding of the cost drivers that will determine nuclear power's cost competitiveness vis-a-vis other baseload generation systems. The common reactor-related costs consist of capital, operating, and decontamination and decommissioning costs. Fuel cycle costs include front-end (pre-irradiation) and back-end (post-irradiation) costs, as well as costs specifically associated with fuel recycling. This analysis reveals that there are large cost uncertainties associated with all the fuel cycle strategies, and that overall systems (reactor plus fuel cycle) using a closed fuel cycle are about 10% more expensive in terms of electricity generation cost than open cycle systems. The study concludes that further U.S. and joint international-based design studies are needed to reduce the cost uncertainties with respect to fast reactor, fuel separation and fabrication, and waste disposition. The results of this work can help provide insight to the cost-related factors and conditions needed to keep nuclear energy (including closed fuel cycles) economically competitive in the U.S. and worldwide. These results may be updated over time based on new cost information, revised assumptions, and feedback received from additional reviews.

  13. Imaging of Lymph Flow in Breast Cancer Patients after Microdose Administration of a Near-Infrared Fluorophore: Feasibility Study1

    Science.gov (United States)

    Sevick-Muraca, Eva M.; Sharma, Ruchi; Rasmussen, John C.; Marshall, Milton V.; Wendt, Juliet A.; Pham, Hoang Q.; Bonefas, Elizabeth; Houston, Jessica P.; Sampath, Lakshmi; Adams, Kristen E.; Blanchard, Darlene Kay; Fisher, Ronald E.; Chiang, Stephen B.; Elledge, Richard; Mawad, Michel E.

    2011-01-01

    Purpose To prospectively demonstrate the feasibility of using indocyanine green, a near-infrared (NIR) fluorophore at the minimum dose needed for noninvasive optical imaging of lymph nodes (LNs) in breast cancer patients undergoing sentinel lymph node mapping (SLNM). Materials and Methods Informed consent was obtained from 24 women (age range, 30–85 years) who received intradermal subcutaneous injections of 0.31–100 μg indocyanine green in the breast in this IRB-approved, HIPAA-compliant, dose escalation study to find the minimum microdose for imaging. The breast, axilla, and sternum were illuminated with NIR light and the fluorescence generated in the tissue was collected with an NIR-sensitive intensified charged-coupled device. Lymphoscintigraphy was also performed. Resected LNs were evaluated for the presence of radioactivity, blue dye accumulation, and fluorescence. The associations between the resected LNs that were fluorescent and (a) the time elapsed between NIR fluorophore administration and resection and (b) the dosage of NIR fluorophores were tested with the Spearman rank and Pearson product moment correlation tests, respectively. Results Lymph imaging consistently failed with indocyanine green microdosages between 0.31 and 0.77 μg. When indocyanine green dosages were 10 μg or higher, lymph drainage pathways from the injection site to LNs were imaged in eight of nine women; lymph propulsion was observed in seven of those eight. When propulsion in the breast and axilla regions was present, the mean apparent velocities ranged from 0.08 to 0.32 cm/sec, the time elapsed between “packets” of propelled fluid varied from 14 to 92 seconds. In patients who received 10 μg of indocyanine green or more, a weak negative correlation between the fluorescence status of resected LNs and the time between NIR fluorophore administration and LN resection was found. No statistical association was found between the fluorescence status of resected LNs and the dose of

  14. Lymphoscintigraphy for sentinel lymph node mapping in Japanese patients with malignant skin neoplasms of the lower extremities. Comparison with previously investigated Japanese lymphatic anatomy

    International Nuclear Information System (INIS)

    Miura, Hiroyuki; Ono, Shuichi; Nagahata, Morio

    2010-01-01

    Lymph nodes (LN) and lymphatic drainage were identified by lymphoscintigraphy using 99m Tc-phytate in order to map the sentinel lymph nodes (SLNs) in patients with malignant skin neoplasms of the lower extremities, and to compare the results with an atlas of Japanese lymphatic anatomy. Sentinel lymphoscintigraphs of 18 patients with malignant skin neoplasms of the lower extremities (9 men, 9 women; age range 45-84 years, mean age 66 years) were analyzed retrospectively, and the LNs detected were identified as SLNs or secondary nodes. The patterns of lymphatic drainage were divided into three different categories: initial drainage into inguinal LN without visualization of popliteal LNs (inguinal type), initial drainage into popliteal LNs and then into intrapelvic LNs (popliteal type), and initial drainage into both popliteal and inguinal LNs (inguinal and popliteal type). More than half of the cases were the inguinal and popliteal type, as both inguinal and popliteal LNs were identified as SLNs. In the cases in which the hallux and its surrounding area were injected, all were the inguinal type and popliteal LNs were not visualized. In one case, only dynamic images detected lymphatic drainage without visualization of popliteal LNs. In contrast to the previously published literature on Japanese lymphatic anatomy, SLN lymphatic drainage from the skin of the lower extremities was wide and overlapping in many areas. However, in agreement with currently accepted anatomy, only the great saphenous lymphatic vessel drained the skin of the hallux and its surrounding area. The present results suggest that it is important to confirm lymphatic drainage in order to identify SLNs in the lower extremities. The patterns of lymphatic drainage from the skin of the foot were divided into three different categories. In contrast to previously published Japanese lymphatic anatomy, lymphatic drainage from the skin of the lower extremities was wide and overlapping in many areas. However

  15. 7254 ACCEPTABILITY OF DIFFERENT LIPID-BASED NUTRIENT ...

    African Journals Online (AJOL)

    Marlène Hébié

    2013-01-01

    Jan 1, 2013 ... acceptability tests with one of four sets of LNS products: LNS-30 g sweet, .... data and analyzed using non-parametric tests: Kruskal–Wallis test, Wilcoxon signed- rank test or Wilcoxon sum rank test to compare 2 groups and ...

  16. Effect of supplementation with a lipid-based nutrient supplement on the micronutrient status of children aged 6–18 months living in the rural region of Intibucá, Honduras

    Science.gov (United States)

    Background: Lipid-based nutrient supplements (LNS) have been effective in the treatment of acute malnutrition among children. We evaluated the use of LNS supplementation for improving the micronutrient status of young children. Methods: A 12-month randomised controlled trial was conducted among chil...

  17. Pharmaceutical and biomedical applications of lipid-based nanocarriers.

    Science.gov (United States)

    Carbone, Claudia; Leonardi, Antonio; Cupri, Sarha; Puglisi, Giovanni; Pignatello, Rosario

    2014-03-01

    Increasing attention is being given to lipid nanocarriers (LNs) as drug delivery systems, due to the advantages offered of a higher biocompatibility and lower toxicity compared with polymeric nanoparticles. Many administration routes are being investigated for LNs, including topical, oral and parenteral ones. LNs are also proposed for specific applications such as cancer treatment, gene therapy, diagnosis and medical devices production. However, the high number of published research articles does not match an equal amount of patents. A recent Review of ours, published in Pharmaceutical Patent Analyst, reported the patents proposing novel methods for the production of LNs. This review work discusses recent patents, filed in 2007-2013 and dealing with the industrial applications of lipid-based nanocarriers for the vectorization of therapeutically relevant molecules, as well as biotech products such as proteins, gene material and vaccines, in the pharmaceutical, diagnostic and biomedical areas.

  18. The utility of intraoperative ultrasound in modified radical neck dissection: a pilot study.

    Science.gov (United States)

    Agcaoglu, Orhan; Aliyev, Shamil; Taskin, Halit Eren; Aksoy, Erol; Siperstein, Allan; Berber, Eren

    2014-04-01

    Although the value of surgeon-performed neck ultrasound (SPUS) for thyroid nodules has been validated, the utility of intraoperative ultrasound (US) in modified radical neck dissection (MRND) has not been reported in the literature. The aim of this study was to analyze the utility of intraoperative SPUS in assessing the completeness of MRND for thyroid cancer. Between 2007 and 2011, a total of 25 patients underwent MRND by 1 surgeon for thyroid cancer. All patients underwent intraoperative SPUS, which was repeated at the end of the neck dissection (completion US) to look for missed lymph nodes (LNs). There were 10 male and 15 female patients. Pathology included 23 papillary and 2 medullary carcinomas. The number of LNs removed per case was 23 ± 2, and the number of positive was LNs 5 ± 1. In 4 (16%) cases, intraoperative US detected 7 residual LNs, which would have been missed, if completion US were not done. These missed LNs were located in low-level IV (3 nodes), high-level II (2 nodes), and posterior level V (2 nodes) and measured 1.4 ± 0.2 cm. At follow-up, recurrence was seen in 2 (8%) patients, including a superior mediastinal recurrence in a patient with tall cell cancer and a jugular LN recurrence at level II in another patient with papillary thyroid cancer. This pilot study shows that intraoperative SPUS can help assess the completeness of MRND. According to our results, intraoperative completion US identifies LNs missed by palpation 16% of the time.

  19. A treatment planning comparison of four target volume contouring guidelines for locally advanced pancreatic cancer radiotherapy

    International Nuclear Information System (INIS)

    Fokas, Emmanouil; Eccles, Cynthia; Patel, Neel; Chu, Kwun-Ye; Warren, Samantha; McKenna, W. Gillies; Brunner, Thomas B.

    2013-01-01

    Background and purpose: Contouring of target volumes varies significantly in radiotherapy of pancreatic ductal adenocarcinoma (PDAC). There is a lack of consensus as to whether elective lymph nodes (eLN’s) should be included or not in the planning target volume (PTV). In the present study we analyzed the dosimetric coverage of the eLN’s and organs at risk (OAR) by comparing four different contouring guidelines. Methods and materials: PTVs were delineated with (Oxford and RTOG guidelines) or without (Michigan and SCALOP guidelines) including the eLNs in eleven patients with PDAC. eLNs included the peripancreatic, paraaortic, paracaval, celiac trunk, superior mesenteric and portal vein clinical target volumes (CTVs). A 3D-CRT plan (50.40 Gy in 28 fractions) was performed to analyze and compare the dosimetric coverage of all eLNs and OAR between the 4 contouring guidelines. Results: The size of Oxford and RTOG PTVs was comparable and significantly larger than the SCALOP and Michigan PTVs. Interestingly the eLNs received a significant amount of incidental dose irradiation by PTV-based plans that only aimed to treat the tumor without the eLNs. The dosimetric coverage of eLN presented a large variability according to the respective contouring methods. The difference in the size of the 4 PTVs was reflected to the dose distribution at the OAR. Conclusions: Our study provides important information regarding the impact of different contouring guidelines on the dose distribution to the eLNs and the OAR in patients with locally advanced PDAC treated with radiotherapy

  20. Effect of supplementation with a lipid-based nutrient supplement on the micronutrient status of children aged 6-18 months living in the rural region of Intibucá, Honduras.

    Science.gov (United States)

    Siega-Riz, Anna M; Estrada Del Campo, Yaniré; Kinlaw, Alan; Reinhart, Gregory A; Allen, Lindsay H; Shahab-Ferdows, Setareh; Heck, Jeff; Suchindran, Chirayath M; Bentley, Margaret E

    2014-05-01

    Lipid-based nutrient supplements (LNS) have been effective in the treatment of acute malnutrition among children. We evaluated the use of LNS supplementation for improving the micronutrient status of young children. A 12-month randomised controlled trial was conducted among children aged 6-18 months living in Intibucá, Honduras. Communities (n = 18) were randomised into clusters matched by poverty indicators (9 intervention, n = 160 and 9 controls, n = 140). Intervention participants received LNS. All children received food vouchers and nutrition education. Primary outcomes included measures of micronutrient status: at baseline, 6 and 12 months' blood were collected for assessment of folate, iron, zinc, riboflavin, and vitamin B12 status; haemoglobin was measured every 3 months; and dietary and anthropometry collected monthly. Longitudinal analyses were based on intent to treat and LNS adherence. Generalised estimating equations were used in the estimation of generalised linear regression models specified for the data. At 6-month follow-up, children in the intervention group had a lower proportion classified as deficient for B12 (43.6%) compared with the control (67.7%; P = 0.03). The intervention group had a higher mean concentration for folate at 6 months (P = 0.06), and improvements continued through 12 months for folate (P = 0.002) and vitamin A deficiency (P = 0.03). This pattern of results, with improved significance, remained in subanalysis based on LNS adherence. These data demonstrate that LNS improved select micronutrient status in young non-malnourished Honduran children. © 2014 John Wiley & Sons Ltd.

  1. Temporary Employment and Perceived Employability: Mediation by Impression Management

    Science.gov (United States)

    De Cuyper, Nele; De Witte, Hans

    2010-01-01

    Perceived employability (PE) has been advanced as the upcoming resource for career development, particularly for temporary workers. The question is how temporary workers become employable. Our hypothesis is that temporary workers more than permanent workers use impression management to become employable, both on the internal and the external labor…

  2. B-Flow Twinkling Sign in Preoperative Evaluation of Cervical Lymph Nodes in Patients with Papillary Thyroid Carcinoma

    Directory of Open Access Journals (Sweden)

    Giuseppina Napolitano

    2013-01-01

    Full Text Available Papillary thyroid cancer (PTC is the most common histologic type of differentiated thyroid cancer. The first site of metastasis is the cervical lymph nodes (LNs. The ultrasonography (US is the best diagnostic method for the detection of cervical metastatic LNs. We use a new technique, B-flow imaging (BFI, recently used for evaluation of thyroid nodules, to estimate the presence of BFI twinkling signs (BFI-TS, within metastatic LNs in patients with PTC. Two hundred and fifty-two patients with known PTC were examined for preoperative evaluation with conventional US and BFI. Only 83 with at least one metastatic LN were included. All patients included underwent surgery; the final diagnosis was based on the results of histology. The following LN characteristics were evaluated: shape, abnormal echogenicity, absent hilum, calcifications, cystic appearance, peripheral vascularization, and BFI-TS. A total of 604 LNs were analyzed. Of these, 298 were metastatic, according to histopathology. The BFI-TS showed high values ​​of specificity (99.7% and sensitivity (80.9%. The combination of each conventional US sign with the BF-TS increases the specificity. Our findings suggest that BFI can be helpful in the selection of suspicious neck LNs that should be examined at cytologic examination for accurate preoperative staging and individual therapy selection.

  3. Welding of Prosthetic Alloys / Spawanie Stopów Protetycznych Typu Co-Cr

    Directory of Open Access Journals (Sweden)

    Wojciechowska M.

    2015-12-01

    Full Text Available This paper presents the techniques of joining metal denture elements, used in prosthetic dentistry: the traditional soldering technique with a gas burner and a new technique of welding with a laser beam; the aim of the study was to make a comparative assessment of the quality of the joints in view of the possibility of applying them in prosthetic structures. Fractographic examinations were conducted along with tensile strength and impact strength tests, and the quality of the joints was assessed compared to the solid metal. The experiments have shown that the metal elements used to make dentures, joined by the technique which employs a laser beam, have better strength properties than those achieved with a gas burner.

  4. Welding of Prosthetic Alloys

    Directory of Open Access Journals (Sweden)

    Wojciechowska M.

    2015-04-01

    Full Text Available This paper presents the techniques of joining metal denture elements, used in prosthetic dentistry: the traditional soldering technique with a gas burner and a new technique of welding with a laser beam; the aim of the study was to make a comparative assessment of the quality of the joints in view of the possibility of applying them in prosthetic structures. Fractographic examinations were conducted along with tensile strength and impact strength tests, and the quality of the joints was assessed compared to the solid metal. The experiments have shown that the metal elements used to make dentures, joined by the technique which employs a laser beam, have better strength properties than those achieved with a gas burner.

  5. Employer Branding

    DEFF Research Database (Denmark)

    Frimann, Søren; Mønsted, Bolette Rye

    2012-01-01

    Employer branding er både for den private og den offentlige sektor blevet en måde, de kan imødekomme ændrede arbejdsmarkedsvilkår og organisatoriske udfordringer i en postmoderne og globaliseret verden. Den aktuelle finanskrise har skabt nye udfordringer for organisationer i deres bestræbelser på...... at tiltrække- og fastholde attraktive medarbejdere. Men hvilken betydning har det, når Grundfos siger ”Mennesket er i fokus”, og hvad siger ”mangfoldighed” om Københavns Kommune som arbejdsplads i relation til employer branding? Er der egentlig sammenhæng mellem tankerne bag employer branding og de eksternt...... kommunikerede employer brandprodukter. Eller bliver det unikke ved arbejdspladserne ersattet af buzzwords uden substans og inddragelse af ansatte og interessenter? Artiklen har til formål at vurdere disse spørgsmål på baggrund af analyser af to cases med employer branding....

  6. Simulasi Numeris Karakteristik Pembakaran CH4/CO2/Udara dan CH4/CO2/O2 pada Counterflow Premixed Burner

    Directory of Open Access Journals (Sweden)

    Hangga Wicaksono

    2017-08-01

    Full Text Available The high amount of CO2 produced in a conventional biogas reactor needs to be considered. A further analysis is needed in order to investigate the effect of CO2 addition especially in thermal and chemical kinetics aspect. This numerical study has been held to analyze the effect of CO2 in CH4/CO2/O­2 and CH4/CO2/Air premixed combustion. In this study one dimensional analisys in a counterflow burner has been performed. The volume fraction of CO2 used in this study was 0%-40% from CH4’s volume fraction, according to the amount of CO2 in general phenomenon. Based on the flammability limits data, the volume fraction of CH4 used was 5-61% in O2 environment and 5-15% in air environment. The results showed a decreasing temperature along with the increasing percentage of CO2 in each mixtures, but the effect was quite smaller especially in stoichiometric and lean mixture. CO2 could affects thermally (by absorbing heat due to its high Cp and also made the production of unburnt fuel species such as CO relatively higher.

  7. THE BANGLADESHI EMPLOYMENT SECTOR: EMPLOYER PERSPECTIVES CONCERNING ENGLISH PROFICIENCY

    Directory of Open Access Journals (Sweden)

    Rubina Khan

    2012-07-01

    Full Text Available Abstract: This paper presents a brief summary of a study which was carried out to investigate how employers representing major employment sectors in the Bangladeshi Industry view the skills and English proficiency level of the current employees. Opinions were also solicited on what skills are required for fresh recruits. Semi-structured interviews were conducted with 30 employers representing the major employment sectors in Bangladeshi Industry. Results revealed the importance of English as an indispensible means of communication in the Bangladeshi corporate sector and showed that the business enterprises use extensive amounts of English. It also highlighted that the existent English proficiency of the employees was far below the required proficiency level. Recommendations were made to address the gap and prepare the youth to meet the demands of the global market. Keywords: English proficiency, competency, employability skills, global literacy skills

  8. Vocational Rehabilitation and Employment program--self-employment. Final rule.

    Science.gov (United States)

    2010-01-20

    This document amends the vocational rehabilitation and employment regulations of the Department of Veterans Affairs (VA) concerning self-employment for individuals with qualifying disabilities. We are making changes to conform VA's regulations for self-employment programs for veterans, and for servicemembers awaiting discharge, to statutory provisions, including provisions limiting eligibility for certain supplies, equipment, stock, and license fees to individuals with the most severe service-connected disabilities. We are also making related changes in VA's regulations affecting eligibility for such assistance for certain veterans' children with birth defects in self-employment programs. In addition, we are amending our regulations regarding the approval authority for self-employment plans to make certain requirements less restrictive and less burdensome, to remove a vague and overly broad requirement, to make changes to reflect longstanding VA policy, and to make nonsubstantive clarifying changes.

  9. The accumulation of regulatory T cells in the hepatic hilar lymph nodes in biliary atresia.

    Science.gov (United States)

    Sakamoto, Naoya; Muraji, Toshihiro; Ohtani, Haruo; Masumoto, Kouji

    2017-10-01

    A proposed etiopathogenesis of biliary atresia (BA) involves T-cell-mediated inflammatory bile duct damage and progressive hepatic fibrosis. Pediatric surgeons often observe swelling of the hepatic hilar lymph nodes during the Kasai procedure. Given the importance of regulatory mechanisms in immune responses, the present study was designed to analyze the quantitative changes of regulatory T cells (T reg cells) in the hepatic hilar lymph nodes (hepatic hilar LNs) and peripheral blood (PB) in BA. The hepatic hilar LNs and PB obtained during the Kasai procedure were analyzed by flow cytometry. The ratios of total and active Tregs to the total CD4 + cells in the PB and the hepatic hilar LNs were compared. In patients with BA, the ratios of both the total and active T reg cells in the hepatic hilar LNs were higher than those in the PB (total T reg cells: PB vs. LN; P hilar lymph nodes of BA patients. This finding could shed light on the pathogenesis of BA.

  10. VERIFICATION OF A TUMOR LESION OF INTRAPELVIC LYMPH NODES AFTER RADICAL PROSTATECTOMY. THE FIRST EXPERIENCE

    Directory of Open Access Journals (Sweden)

    V. V. Kapustin

    2014-08-01

    Full Text Available Objective: to study the possibilities of transrectal ultrasound scan (TRUS and magnetic resonance imaging (MRI in identifying and verifying a tumor lesion of intrapelvic lymph nodes (LN in patients with biochemical recurrence after radical prostatectomy.Subjects and methods. Metastatic tumor lesion of intrapelvic LNs was verified in 4 patients by transrectal ultrasound (US-guided needle biopsies. All the patients underwent multi-parametric MRI studies and TRUS.Results. The application of current MRI technologies (for qualitative and quantitative analysis of diffusion-weighted images and for postcontrast sequences could detect and judge with confidence the metastatic lesion of intrapelvic LNs. TRUS permits clearly visualizing pathologically altered LNs, by taking into account their MRI pattern and verifying their tumor lesion by US-guided core needle biopsy.Conclusion. The combined use of multi-parametric MRI and TRUS provides a means for diagnosing and verifying the tumor lesion of pelvic LNs in patients after prostatectomy.

  11. VERIFICATION OF A TUMOR LESION OF INTRAPELVIC LYMPH NODES AFTER RADICAL PROSTATECTOMY. THE FIRST EXPERIENCE

    Directory of Open Access Journals (Sweden)

    V. V. Kapustin

    2012-01-01

    Full Text Available Objective: to study the possibilities of transrectal ultrasound scan (TRUS and magnetic resonance imaging (MRI in identifying and verifying a tumor lesion of intrapelvic lymph nodes (LN in patients with biochemical recurrence after radical prostatectomy.Subjects and methods. Metastatic tumor lesion of intrapelvic LNs was verified in 4 patients by transrectal ultrasound (US-guided needle biopsies. All the patients underwent multi-parametric MRI studies and TRUS.Results. The application of current MRI technologies (for qualitative and quantitative analysis of diffusion-weighted images and for postcontrast sequences could detect and judge with confidence the metastatic lesion of intrapelvic LNs. TRUS permits clearly visualizing pathologically altered LNs, by taking into account their MRI pattern and verifying their tumor lesion by US-guided core needle biopsy.Conclusion. The combined use of multi-parametric MRI and TRUS provides a means for diagnosing and verifying the tumor lesion of pelvic LNs in patients after prostatectomy.

  12. Becoming Self-Employed.

    Science.gov (United States)

    Lee, Grant; Cochran, Larry

    1997-01-01

    Explored how persons become self-employed. In critical incident interviews with five self-employed persons the critical events that assisted or hindered progress toward self-employment were listed in chronological order. In general, becoming self-employed involved establishing conditions of action that enhanced a sense of agency, thus enabling…

  13. Employer's Manual on Affirmative Action in Employment.

    Science.gov (United States)

    Kentucky State Commission on Human Rights, Frankfort.

    The express purpose of this manual is for its use by business and industry in Kentucky as an aid to eliminate discrimination. Affirmative action is defined here as a comprehensive effort by an employer designed to: employ women and minority persons where they are under-utilized; include minority persons and women in all facets of the company's…

  14. Consideration of myocardial FDG uptake in differentiation of mediastinal lymph node of non-small cell lung cancer

    International Nuclear Information System (INIS)

    Eo, Jae Seon; Lee, Won Woo; Chung, Jin Haeng; So, Young; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul; Kim, Sang Eun

    2004-01-01

    The whole body FDG PET suffers from poor diagnostic competency in differentiation of mediastinal lymph node (LN) in non-small cell lung cancer. In addition to LN FDG uptake. We considered myocardial FDG uptake in mediastinal lymph node staging. Thirty-nine non-small cell lung cancer patients (male: female = 32: 7, age = 63±11 years) who underwent preoperative whole body FDG PET were enrolled. There were 18 squamous cell cancer, 13 adenocarcinoma, and 8 others. Maximum standard uptake values (maxSUVs) of myocardium and LNs using lean body weight were measured and compared with pathological results. Among 187 LNs which were confirmed postoperatively, 31 were malignant, and 156 benign. Of 31 malignant LNs, only 11 were visible on FDG PET (sensitivity : 35.5% = 11/31) but majority of 20 nonvisible metastatic LNs had relevant cause of false negative (11 peribroncheal, 3 mucine producing adenocarcinoma, or 6 low amount of tumor cells). Of 156 benign LNs, 137 were nonvisible (specificity : 87.8% 137/156) and 19 visible. Under subgroup analysis of 30 visible LNs on whole body FDG PET (11 malignant, and 19 benign), maxSUV of myocardium (p = 0.020) as well as maxSUV of LN (p = 0.002) were significant predictor of malignant LN in multivariate analysis. Using the ROC curve, a cut-off value of LN maxSUV > 2.4 provided sensitivity of 81.8% and specificity of 63.2% (AUC 0.775, 95% confidence interval = 0.586 to 0.906). Meanwhile, the composite criterion of LN maxSUV plus square root of myocardial maxSUV > 4.65 provided slightly improved diagnostic competencies (sensitivity 90.9%, specificity 84.2%, AUC 0.876, 95% confidence interval 0.704 to 0.966) (p = 0.08). Taking into consideration myocardial FDG uptake may improve the diagnostic competency of whole body FDG PET in differentiation of mediastinal LNs of non-small cell lung cancer

  15. Employability Skills, Personal Qualities, and Early Employment Problems of Entry-Level Auditors: Perspectives from Employers, Lecturers, Auditors, and Students

    Science.gov (United States)

    Lim, Yet-Mee; Lee, Teck Heang; Yap, Ching Seng; Ling, Chui Ching

    2016-01-01

    The authors examine the issue of employability of university accounting students from the perspectives of accounting firm employers, junior auditors, accounting lecturers, and accounting students. Areas of investigation include perceived importance of employability skills and desirable personal qualities; and early employment problems encountered…

  16. Status of the Catania tandem as injector of the superconducting cyclotron

    International Nuclear Information System (INIS)

    Ciavola, G.; Cuttone, G.; Raia, G.

    1990-01-01

    The Catania LNS tandem facility is operating since 1984. The status and the main modifications of the accelerator during these years are described and the performance obtained is reported. A superconducting cyclotron will be installed at the LNS facility as tandem booster; the main progress is presented. (orig.)

  17. Linear growth increased in young children in an urban slum of Haiti: a randomized controlled trial of a lipid-based nutrient supplement.

    Science.gov (United States)

    Iannotti, Lora L; Dulience, Sherlie Jean Louis; Green, Jamie; Joseph, Saminetha; François, Judith; Anténor, Marie-Lucie; Lesorogol, Carolyn; Mounce, Jacqueline; Nickerson, Nathan M

    2014-01-01

    Haiti has experienced rapid urbanization that has exacerbated poverty and undernutrition in large slum areas. Stunting affects 1 in 5 young children. We aimed to test the efficacy of a daily lipid-based nutrient supplement (LNS) for increased linear growth in young children. Healthy, singleton infants aged 6-11 mo (n = 589) were recruited from an urban slum of Cap Haitien and randomly assigned to receive: 1) a control; 2) a 3-mo LNS; or 3) a 6-mo LNS. The LNS provided 108 kcal and other nutrients including vitamin A, vitamin B-12, iron, and zinc at ≥80% of the recommended amounts. Infants were followed monthly on growth, morbidity, and developmental outcomes over a 6-mo intervention period and at one additional time point 6 mo postintervention to assess sustained effects. The Bonferroni multiple comparisons test was applied, and generalized least-squares (GLS) regressions with mixed effects was used to examine impacts longitudinally. Baseline characteristics did not differ by trial arm except for a higher mean age in the 6-mo LNS group. GLS modeling showed LNS supplementation for 6 mo significantly increased the length-for-age z score (±SE) by 0.13 ± 0.05 and the weight-for-age z score by 0.12 ± 0.02 compared with in the control group after adjustment for child age (P < 0.001). The effects were sustained 6 mo postintervention. Morbidity and developmental outcomes did not differ by trial arm. A low-energy, fortified product improved the linear growth of young children in this urban setting. The trial was registered at clinicaltrials.gov as NCT01552512.

  18. A Clinical Decision Support System Using Ultrasound Textures and Radiologic Features to Distinguish Metastasis From Tumor-Free Cervical Lymph Nodes in Patients With Papillary Thyroid Carcinoma.

    Science.gov (United States)

    Abbasian Ardakani, Ali; Reiazi, Reza; Mohammadi, Afshin

    2018-03-30

    This study investigated the potential of a clinical decision support approach for the classification of metastatic and tumor-free cervical lymph nodes (LNs) in papillary thyroid carcinoma on the basis of radiologic and textural analysis through ultrasound (US) imaging. In this research, 170 metastatic and 170 tumor-free LNs were examined by the proposed clinical decision support method. To discover the difference between the groups, US imaging was used for the extraction of radiologic and textural features. The radiologic features in the B-mode scans included the echogenicity, margin, shape, and presence of microcalcification. To extract the textural features, a wavelet transform was applied. A support vector machine classifier was used to classify the LNs. In the training set data, a combination of radiologic and textural features represented the best performance with sensitivity, specificity, accuracy, and area under the curve (AUC) values of 97.14%, 98.57%, 97.86%, and 0.994, respectively, whereas the classification based on radiologic and textural features alone yielded lower performance, with AUCs of 0.964 and 0.922. On testing the data set, the proposed model could classify the tumor-free and metastatic LNs with an AUC of 0.952, which corresponded to sensitivity, specificity, and accuracy of 93.33%, 96.66%, and 95.00%. The clinical decision support method based on textural and radiologic features has the potential to characterize LNs via 2-dimensional US. Therefore, it can be used as a supplementary technique in daily clinical practice to improve radiologists' understanding of conventional US imaging for characterizing LNs. © 2018 by the American Institute of Ultrasound in Medicine.

  19. Employer branding

    OpenAIRE

    Mičková, Kateřina

    2008-01-01

    The demand for qualified employees is higher then the offering, both in Czech republic and internationally. Demand for specific skills, in addition to a greater demand for workforce generally, is making employee recruitment and retention much more difficult and expensive. Employer Branding claims to be an answer to this new challenge. This international concept focuses on developing an "employer brand" - mental image of a company as an employer. To achieve this, it is necessary to demonstrate...

  20. Building Employer Capacity to Support Meaningful Employment for Persons with Developmental Disabilities: A Grounded Theory Study of Employment Support Perspectives.

    Science.gov (United States)

    Rashid, Marghalara; Hodgetts, Sandra; Nicholas, David

    2017-11-01

    To explore strategies to build employer capacity to support people with DD in meaningful employment from perspective of employment support workers. A grounded theory study was conducted with 34 employment support individuals. A theoretical sampling approach was used to identify and recruit participants from multiple sites in Ontario and Alberta. Three main themes, with seven sub-themes, emerged: (1) experiences of supporting employment finding for people with DD, (2) institutional influences on employee experiences, and (3) attitudes, assumptions and stigma. Several recommendations related to building employer capacity were offered. Our findings provide insight on specific elements and strategies that can support building employer capacity for persons with DD.

  1. Application of a novel calcium looping process for production of heat and carbon dioxide enrichment of greenhouses

    International Nuclear Information System (INIS)

    Ramezani, Mohammad; Shah, Kalpit; Doroodchi, Elham; Moghtaderi, Behdad

    2015-01-01

    Highlights: • The greenhouse calcium looping process was developed by ASPEN Plus simulator. • In this process, the carbonation reaction provides required heat during night time. • The calcination reaction provides required carbon dioxide during day time. • This novel process saves up to 72% energy compared to the fossil fuel burners. • The process thermodynamically attributes to zero emission of carbon dioxide. - Abstract: Greenhouses typically employ conventional burner systems to suffice heat and carbon dioxide required for plant growth. The energy requirement and carbon dioxide emissions from fossil fuel burner are generally high. As an alternative, this paper describes a novel greenhouse calcium looping process which is expected to decrease the energy requirements and associated carbon dioxide emissions. The conceptual design of greenhouse calcium looping process is carried out in the ASPEN Plus v 7.3 simulator. In a greenhouse calcium looping process, the calcination reaction is considered to take place during day time in order to provide the required optimum carbon dioxide between 1000 and 2000 ppm, while the carbonation reaction is occurred during night time to provide required heat. The process simulations carried out in ASPEN indicates that greenhouse calcium looping process theoretically attributes to zero emission of carbon dioxide. Moreover, in a scenario modelling study compared to the conventional natural gas burner system, the heat duty requirements in the greenhouse calcium looping process were found to reduce by as high as 72%

  2. Flexible employment, precarious employees? Job-, employer- and institutional explanations for numerical flexibility, and its relation to precarious employment

    NARCIS (Netherlands)

    Olsthoorn, M.

    2015-01-01

    This dissertation presents a study of numerical flexibility and its relation to precarious employment in contemporary labour markets. Precarious employment is defined as the situation in which an employee has both insecure employment and insecure finances. More specifically, precarious employees are

  3. Employer Branding

    OpenAIRE

    Stroblová, Zuzana

    2017-01-01

    The aim of the Master Thesis is to describe how to build Employer Brand a company. It is based on the description of Employer Branding project of a particular company and the evaluation its process. The thesis is a case study and consists of theoretical and practical part. The theoretical part focuses on trends and changes in leadership approach, definition of Employer Branding and HR Marketing. The practical part deals with the brand building process itself, describes the outputs of the proj...

  4. A Conceptual Understanding of Employability: The Employers' View in Rwanda

    Science.gov (United States)

    Bamwesiga, Penelope Mbabazi

    2013-01-01

    Many governments believe that investing in human capital should increase citizens' employability, which is why it is often presented as a solution to the problems of knowledge-based economies and societies, rising unemployment rates and economic competiveness. The aim of this study is to understand employers' views regarding the employability of…

  5. Prophylactic Level VII Nodal Dissection as a Prognostic Factor in Papillary Thyroid Carcinoma: a Pilot Study of 27 Patients.

    Science.gov (United States)

    Fayek, Ihab Samy

    2015-01-01

    Prognostic value of prophylactic level VII nodal dissection in papillary thyroid carcinoma has been highlighted. A total of 27 patients with papillary thyroid carcinoma with N0 neck underwent total thyroidectomy with level VI and VII nodal dissection through same collar neck incision. Multicentricity, bilaterality, extrathyroidal extension, level VI and VII lymph nodes were studied as separate and independent prognostic factors for DFS at 24 months. 21 females and 6 males with a mean age of 34.6 years old, tumor size was 5-24 mm. (mean 12.4 mm.), multicentricity in 11 patients 2-4 foci (mean 2.7), bilaterality in 8 patients and extrathyroidal extension in 8 patients. Dissected level VI LNs 2-8 (mean 5 LNs) and level VII LNs 1-4 (mean 1.9). Metastatic level VI LNs 0-3 (mean 1) and level VII LNs 0-2 (mean 0.5). Follow-up from 6-51 months (mean 25.6) with 7 patients showed recurrence (3 local and 4 distant). Cumulative DFS at 24 months was 87.8% and was significantly affected in relation to bilaterality (p-valueVII positive ((p-valueVII nodal involvement. Level VII prophylactic nodal dissection is an important and integral prognostic factor in papillary thyroid carcinoma. A larger multicenter study is crucial to reach a satisfactory conclusion about the necessity and safety of this approach.

  6. Development and Physico-Chemical Characterization of a Shea Butter-Containing Lipid Nutrition Supplement for Sub-Saharan Africa

    Directory of Open Access Journals (Sweden)

    Elizabeth M. Sloffer

    2017-11-01

    Full Text Available Lipid-based nutrient supplements (LNS are used to prevent and treat moderate and severe acute malnutrition, a leading cause of mortality in children-under-five. The physical and chemical changes of two new LNS products were evaluated before and after accelerated shelf life testing (ASLT according to protocols suggested by the U.S. Agency for International Development (USAID and Doctors without Borders and compared against USAID’s A-20 paste as a control. LNS formulas containing Shea butter from the Shea nut tree (Vitellaria paradoxa, a common fat source in parts of Sub-Saharan Africa, with and without flax-seed oil, as a source of omega-3 fatty acids, were developed. LNS formulas were batched (0.8 kg in a wet grinder, sealed under nitrogen in three-layer mini-pouches (20 g, and underwent ASLT at 40 ± 2 °C for six months with sampling every eight weeks. At each time point, water activity, moisture, peroxide value, oil separation, vitamin C content, and hardness were evaluated. Results showed comparable stability among all formulas with an increase in Aw (p < 0.05 but no change in vitamin C, oil separation, or peroxide value. Addition of Shea butter improved the LNS’s hardness, which remained stable over time. Modifying fat profile in LNS can improve its texture and essential fatty acid content without affecting its storage stability.

  7. Sono-elastography for Differentiating Benign and Malignant Cervical Lymph Nodes: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Ghajarzadeh, Mahsa; Mohammadifar, Mehdi; Azarkhish, Kamran; Emami-Razavi, Seyed Hassan

    2014-01-01

    We did this systematic review to determine diagnostic accuracy of sono-elastography in evaluating cervical lymph nodes (LNs). A highly sensitive search for sono-elastography and LNs was performed in MEDLINE, Cochrane Library, ACP Journal Club, EMBASE, Health Technology assessment, and ISI web of knowledge for studies published prior to December 2012. SPSS version 18 (SPSS Inc., Chicago, IL, USA) used for descriptive analysis and meta-disk version 1.4 applied for meta-analysis. Forest plots for pooled estimates and summery of receiver operating characteristic plots for different cut-offs were produced. The literature and manual search yielded 69 articles, of which 10 were eligible to include. A total of 578 individuals with a total number of 936 cervical LNs was evaluated (502 malignant and 434 benign). The summary sensitivity of the scoring and strain ratio (SR) measurements for the differentiation of benign and malignant LNs were 0.76 (95% CI: 0.71–0.8) and 0.83 (95% CI: 0.78–0.87). The summary specificities were 0.8 (95% confidence interval [CI]: 0.75–0.84) and 0.84 (95% CI: 0.79–0.88), respectively. Area under the curve for scoring system was 0.86 (standard error [SE] = 0.03) and 0.95 (SE = 0.02) for SR measurement. Sono-elastograohy has high accuracy in differentiating benign and malignant cervical LNs. PMID:25709787

  8. A decision tree model for predicting mediastinal lymph node metastasis in non-small cell lung cancer with F-18 FDG PET/CT.

    Science.gov (United States)

    Pak, Kyoungjune; Kim, Keunyoung; Kim, Mi-Hyun; Eom, Jung Seop; Lee, Min Ki; Cho, Jeong Su; Kim, Yun Seong; Kim, Bum Soo; Kim, Seong Jang; Kim, In Joo

    2018-01-01

    We aimed to develop a decision tree model to improve diagnostic performance of positron emission tomography/computed tomography (PET/CT) to detect metastatic lymph nodes (LN) in non-small cell lung cancer (NSCLC). 115 patients with NSCLC were included in this study. The training dataset included 66 patients. A decision tree model was developed with 9 variables, and validated with 49 patients: short and long diameters of LNs, ratio of short and long diameters, maximum standardized uptake value (SUVmax) of LN, mean hounsfield unit, ratio of LN SUVmax and ascending aorta SUVmax (LN/AA), and ratio of LN SUVmax and superior vena cava SUVmax. A total of 301 LNs of 115 patients were evaluated in this study. Nodular calcification was applied as the initial imaging parameter, and LN SUVmax (≥3.95) was assessed as the second. LN/AA (≥2.92) was required to high LN SUVmax. Sensitivity was 50% for training dataset, and 40% for validation dataset. However, specificity was 99.28% for training dataset, and 96.23% for validation dataset. In conclusion, we have developed a new decision tree model for interpreting mediastinal LNs. All LNs with nodular calcification were benign, and LNs with high LN SUVmax and high LN/AA were metastatic Further studies are needed to incorporate subjective parameters and pathologic evaluations into a decision tree model to improve the test performance of PET/CT.

  9. Sono-elastography for Differentiating Benign and Malignant Cervical Lymph Nodes: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Ghajarzadeh, Mahsa; Mohammadifar, Mehdi; Azarkhish, Kamran; Emami-Razavi, Seyed Hassan

    2014-12-01

    We did this systematic review to determine diagnostic accuracy of sono-elastography in evaluating cervical lymph nodes (LNs). A highly sensitive search for sono-elastography and LNs was performed in MEDLINE, Cochrane Library, ACP Journal Club, EMBASE, Health Technology assessment, and ISI web of knowledge for studies published prior to December 2012. SPSS version 18 (SPSS Inc., Chicago, IL, USA) used for descriptive analysis and meta-disk version 1.4 applied for meta-analysis. Forest plots for pooled estimates and summery of receiver operating characteristic plots for different cut-offs were produced. The literature and manual search yielded 69 articles, of which 10 were eligible to include. A total of 578 individuals with a total number of 936 cervical LNs was evaluated (502 malignant and 434 benign). The summary sensitivity of the scoring and strain ratio (SR) measurements for the differentiation of benign and malignant LNs were 0.76 (95% CI: 0.71-0.8) and 0.83 (95% CI: 0.78-0.87). The summary specificities were 0.8 (95% confidence interval [CI]: 0.75-0.84) and 0.84 (95% CI: 0.79-0.88), respectively. Area under the curve for scoring system was 0.86 (standard error [SE] = 0.03) and 0.95 (SE = 0.02) for SR measurement. Sono-elastograohy has high accuracy in differentiating benign and malignant cervical LNs.

  10. Employer perceptions of the employability of workers in a social business.

    Science.gov (United States)

    Krupa, Terry; Howell-Moneta, Angela; Lysaght, Rosemary; Kirsh, Bonnie

    2016-06-01

    This study examined employer perceptions of employability of job candidates working in a social business for people with mental illnesses. Using an analogue research design, 99 employers participated in a simulated job hiring process, rating 2 applicants on potential to do the job, fit with workplace culture and likelihood of hiring. One job applicant worked in a social business, and the second was either (a) working in a conventional business, (b) with employment lapse attributable to mental health issues, or (c) with an unexplained employment lapse. Paired samples t tests were used to compare ratings. Qualitative data were collected regarding the rationale for rankings and a content analysis was conducted. Employer rankings were significantly higher for the applicant working in a social business compared to either applicant with an employment lapse. Employers rated the candidate working in a conventional business significantly higher compared with the candidate in a social business only on ratings of likelihood to hire. Employers valued the recency of work experience in the social business, citing concerns about risks associated with employment lapses. Their comments suggested a lack of understanding of the nature of social business. Experience in a social business appears to lessen the disadvantage of unemployment in the job hiring process, but does not appear to be ranked on par with experience in the conventional workforce. The social business sector could benefit from considering ways to publically portray these work opportunities to enhance acceptance and inclusion. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  11. Analysis of the prognostic factors for low rectal cancer with the pT1-2NxM0 stage after abdominoperineal resection.

    Science.gov (United States)

    Zhang, Xing-mao; Ma, Chao; Sun, Da-yong; Wang, Zheng; Zhou, Zhi-xiang

    2015-01-01

    This study was designed to explore the factors influencing local recurrence and survival for low rectal cancer with pT1-2NxM0 stage after an abdominoperineal resection (APR). Data of 429 patients confirmed to have pT1-2NxM0 after APR were reviewed. The recurrence rate in patients with intraoperative perforation, less than 12 lymph nodes (LNs) harvested, T2 staging, and positive circumferential resection margin (CRM) was 25.1, 19.9, 9.5, and 26.1% compared with 6.9, 7.0, 0, and 5.8% in patients with no perforation, 12 or more LNs harvested, T1, and negative CRM. The 5-year survival rate in patients with age of at least 70, perforation, less than 12 LNs harvested, T2, and positive CRM was 71.1, 60.8, 58.8, 69.9, and 46.0%, but 73.4, 73.5, 73.8, 89.4, and 75.0% in patients with age less than 70, no perforation, 12 or more LNs harvested, T1, and negative CRM. Meanwhile, patients with N0, N1, and N2 had a survival rate of 90.7, 69.9, and 63.9%. Multivariate analysis showed that perforation (PCRM status (P=0.002) were associated with local recurrence, whereas age of the patients (P=0.023), N staging (PCRM status (P=0.004) were associated with survival. APR was affected by patients' age, operation performer, perforation, number of LNs harvested, T staging, N staging, differentiation, and CRM status. Perforation, number of LNs harvested, T staging, differentiation, and CRM status were independent factors for recurrence; meanwhile, age of the patients, N staging, differentiation, and CRM status were independent factors influencing survival.

  12. Holy smoke in medieval funerary rites: chemical fingerprints of frankincense in southern Belgian incense burners.

    Science.gov (United States)

    Baeten, Jan; Deforce, Koen; Challe, Sophie; De Vos, Dirk; Degryse, Patrick

    2014-01-01

    Frankincense, the oleogum resin from Boswellia sp., has been an early luxury good in both Western and Eastern societies and is particularly used in Christian funerary and liturgical rites. The scant grave goods in late medieval burials comprise laterally perforated pottery vessels which are usually filled with charcoal. They occur in most regions of western Europe and are interpreted as incense burners but have never been investigated with advanced analytical techniques. We herein present chemical and anthracological results on perforated funerary pots from 4 Wallonian sites dating to the 12-14th century AD. Chromatographic and mass spectrometric analysis of lipid extracts of the ancient residues and comparison with extracts from four Boswellia species clearly evidence the presence of degraded frankincense in the former, based on characteristic triterpenoids, viz. boswellic and tirucallic acids, and their myriad dehydrated and oxygenated derivatives. Cembrane-type diterpenoids indicate B. sacra (southern Arabia) and B. serrata (India) as possible botanical origins. Furthermore, traces of juniper and possibly pine tar demonstrate that small amounts of locally available fragrances were mixed with frankincense, most likely to reduce its cost. Additionally, markers of ruminant fats in one sample from a domestic context indicate that this vessel was used for food preparation. Anthracological analysis demonstrates that the charcoal was used as fuel only and that no fragrant wood species were burned. The chars derived from local woody plants and were most likely recovered from domestic fires. Furthermore, vessel recycling is indicated by both contextual and biomarker evidence. The results shed a new light on funerary practices in the Middle Ages and at the same time reveal useful insights into the chemistry of burned frankincense. The discovery of novel biomarkers, namely Δ2-boswellic acids and a series of polyunsaturated and aromatic hydrocarbons, demonstrates the high

  13. Employment in Agribusiness.

    Science.gov (United States)

    Hilgenberg, Gene; Huston, Jane

    This curriculum guide is intended to assist persons teaching a course in employment in agribusiness. Addressed in the individual units of instruction are the following topics: employment information (training plans/agreements and wages, taxes, and fringe benefits); human relations (employer/employee/customer relations and communication skills);…

  14. Investigations of coal ignition in a short-range flame burner using optical measuring systems; Untersuchungen zur Kohlezuendung am Flachflammenbrenner unter Verwendung optischer Messtechnik

    Energy Technology Data Exchange (ETDEWEB)

    Hackert, G.; Kremer, H.; Wirtz, S. [Bochum Univ. (Germany). Lehrstuhl fuer Energieanlagentechnik

    1999-09-01

    The short-range flame burner and the KOALA reactor of DMT are experimental facilities for realistic simulation of coal conversion processes at high temperatures and pressures in atmospheric conditions. The TOSCA system enable measurements of temperatures, sizes, shapes and velocities of the fuel particles, which serve as a basis for a three-dimensional simulation model of coal combustion. In the future, further parameter studies will deepen the present knowledge of coal dust combustion under pressure and enable optimisation of the numerical models for simulation of industrial-scale systems for coal dust combustion under pressure. [Deutsch] Mit dem Flachflammenbrenner und dem KOALA-Reaktor der DMT stehen Versuchsapparaturen zur Verfuegung, mit deren Hilfe die Kohleumwandlungsprozesse bei hohen Temperaturen unter Druck und unter atmosphaerischen Bedingungen realistisch wiedergegeben werden. Das TOSCA-System erlaubt dabei die Bestimmung von Temperaturen, Groessen, Formen und Geschwindigkeiten der Brennstoffpartikel. Diese Daten liefern die Grundlage fuer die Erstellung eines dreidimensionalen Simulationsmodells zur Modellierung der Kohleverbrennung. In Zukunft werden weitere Parameterstudien das Verstaendnis der Kohlenstaubdruckverbrennung vertiefen und ein Optimierung der numerischen Modelle ermoeglichen, so dass die Simulation grosstechnischer Kohlenstaubdruckverbrennungsanlagen realisiert werden kann. (orig.)

  15. VIA Employability

    DEFF Research Database (Denmark)

    Andersen, Henrik Mariendal

    2017-01-01

    ’s realized at the entrance to the labor market and in the future career. The purpose is to find opportunities to improve employability-developing activities and to adapt it to specific needs from the students. Based on a number of qualitative interviews and personality tests of the graduates, an increased......The fact that students develop employability during their education is a key point for educational institutions and the focus on this issue has never been greater. This project looks into personal experience from VIA-graduates of "developing their employability" during the education and how it...

  16. Lesch-nyhan syndrome in an Indian child

    Directory of Open Access Journals (Sweden)

    Priyanka Chandekar

    2015-01-01

    Full Text Available Hypoxanthine guanine phosphoribosyl transferase-1 (HGPRT-1 leading to Lesch-Nyhan syndrome (LNS is one of the important causes of self-mutilation. Hereby, we report a case of LNS in a three and half-year-old male child, who presented with characteristic self-mutilating behavior. He had history of developmental delay, difficulty in social interaction, attention deficit and features of autism. His serum blood biochemistry was normal except for low hemoglobin levels and raised serum uric acid levels. With a diagnosis of LNS, the child was treated with allopurinol. With various modalities of physical restraint, his self-mutilating behavior came under control and currently the patient is being followed up.

  17. Which employment interview skills best predict the employability of schizophrenic patients?

    Science.gov (United States)

    Charisiou, J; Jackson, H J; Boyle, G J; Burgess, P M; Minas, I H; Joshua, S D

    1989-06-01

    To examine the effects of verbal and nonverbal interview microbehaviors and interview characteristics on employability, Simulated Employment Interviews were conducted with 46 psychiatric inpatients who each met the DSM-III criteria for a diagnosis of schizophrenia. Each interview was videotaped and shown to two raters, who generated independent ratings for six microbehaviors (eye-contact, facial gestures, body posture, verbal content, voice volume, and length of speech) and six subject characteristics (motivation, self-confidence, ability to communicate, manifest adjustment, manifest intelligence and overall interview skill). A panel of three Commonwealth Employment Service psychologists viewed the same videotaped interviews and generated employability ratings. Verbal and nonverbal microbehaviors were relatively independent while subject characteristics were highly interdependent. Microbehaviors and characteristics correlated at a high level. Of the 12 interview microbehaviors and characteristics, manifest adjustment and ability to communicate accounted for 64% of the total variance in predicting employability. Interviewees who were perceived as behaving in an adjusted manner and as being good communicators were rated as more employable.

  18. Esophageal motion characteristics in thoracic esophageal cancer: Impact of clinical stage T4 versus stages T1-T3

    Directory of Open Access Journals (Sweden)

    Yuta Kobayashi, MS

    2016-10-01

    Conclusions: The EM and the ITV margins in cT4 were significantly smaller than those in cT1-T3. The NM and the ITV margins of abdominal LNs were much larger than those of cervicothoracic LNs and the esophagus. In clinical radiation therapy planning for esophageal cancer, we should take cT stage into consideration.

  19. 20 CFR 404.1003 - Employment.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Employment. 404.1003 Section 404.1003...- ) Employment, Wages, Self-Employment, and Self-Employment Income Employment § 404.1003 Employment. Employment....1010. Section 404.1004 states the general rule on the kinds of work covered as employment. Exceptions...

  20. Experimental study of a laminar premixed LFG/air flame in a slot burner using Mach-Zehnder interferometry

    Directory of Open Access Journals (Sweden)

    Najafian Ashrafi Zabihollah

    2016-01-01

    Full Text Available An experimental study was conducted to investigate the influence of Reynolds number and equivalence ratio on flame temperature field and thermal flame height of laminar premixed LFG fuel. Mach-Zehnder interferometry technique is used to obtain an insight to the overall temperature field. The slot burner with large aspect ratio (L/W, length of L=60 mm and width of W=6 mm was used to eliminate the three- dimensional effect of temperature field. Two kinds of mixed fuels, LFG70 (70%CH4- 30%CO2 on volume basis and LFG50 (50%CH4- 50%CO2 were used to investigate flame characteristics under the test conditions of 100 ≤ Re ≤ 600 and 0.7 ≤ φ ≤ 1.3. The present measurement reveals that the variation of maximum flame temperature with increment of Reynolds number is mainly due to heat transfer effects and is negligible. On the other hand, the equivalence ratio and fuel composition have a noticeable effect on flame temperature. In addition, the results show that the LFG flames compared to the CH4 ones have a lower flame temperature. With increment of CO2 volume fraction at lean combustion, thermal flame height is augmented while at stoichiometric and rich combustion, its value reduced. Thermal flame height augments linearly by Reynolds number increase, while its increment at rich mixture is higher and the effect of Reynolds number at lean mixtures is insignificant. For validation of experimental results from Mach-Zehnder Interferometry, K-type thermocouples are used at peripherally low and moderate isotherm lines.