WorldWideScience

Sample records for surrounding combustible material

  1. Materials for High-Temperature Catalytic Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ersson, Anders

    2003-04-01

    Catalytic combustion is an environmentally friendly technique to combust fuels in e.g. gas turbines. Introducing a catalyst into the combustion chamber of a gas turbine allows combustion outside the normal flammability limits. Hence, the adiabatic flame temperature may be lowered below the threshold temperature for thermal NO{sub X} formation while maintaining a stable combustion. However, several challenges are connected to the application of catalytic combustion in gas turbines. The first part of this thesis reviews the use of catalytic combustion in gas turbines. The influence of the fuel has been studied and compared over different catalyst materials. The material section is divided into two parts. The first concerns bimetallic palladium catalysts. These catalysts showed a more stable activity compared to their pure palladium counterparts for methane combustion. This was verified both by using an annular reactor at ambient pressure and a pilot-scale reactor at elevated pressures and flows closely resembling the ones found in a gas turbine combustor. The second part concerns high-temperature materials, which may be used either as active or washcoat materials. A novel group of materials for catalysis, i.e. garnets, has been synthesised and tested in combustion of methane, a low-heating value gas and diesel fuel. The garnets showed some interesting abilities especially for combustion of low-heating value, LHV, gas. Two other materials were also studied, i.e. spinels and hexa aluminates, both showed very promising thermal stability and the substituted hexa aluminates also showed a good catalytic activity. Finally, deactivation of the catalyst materials was studied. In this part the sulphur poisoning of palladium, platinum and the above-mentioned complex metal oxides has been studied for combustion of a LHV gas. Platinum and surprisingly the garnet were least deactivated. Palladium was severely affected for methane combustion while the other washcoat materials were

  2. Testing fireproof materials in a combustion chamber

    Directory of Open Access Journals (Sweden)

    Kulhavy Petr

    2017-01-01

    Full Text Available This article deals with a prototype concept, real experiment and numerical simulation of a combustion chamber, designed for testing fire resistance some new insulating composite materials. This concept of a device used for testing various materials, providing possibility of monitoring temperatures during controlled gas combustion. As a fuel for the combustion process propane butane mixture has been used and also several kinds of burners with various conditions of inlet air (forced, free and fuel flows were tested. The tested samples were layered sandwich materials based on various materials or foams, used as fillers in fire shutters. The temperature distribution was measured by using thermocouples. A simulation of whole concept of experimental chamber has been carried out as the non-premixed combustion process in the commercial final volume sw Pyrosim. The result was to design chamber with a construction suitable, according to the international standards, achieve the required values (temperature in time. Model of the combustion based on a stoichiometric defined mixture of gas and the tested layered samples showed good conformity with experimental results – i.e. thermal distribution inside and heat release rate that has gone through the sample.

  3. Oxy-Combustion Boiler Material Development

    Energy Technology Data Exchange (ETDEWEB)

    Gagliano, Michael; Seltzer, Andrew; Agarwal, Hans; Robertson, Archie; Wang, Lun

    2012-01-31

    Under U.S. Department of Energy Cooperative Agreement No. DE-NT0005262 Foster Wheeler North America Corp conducted a laboratory test program to determine the effect of oxy-combustion on boiler tube corrosion. In this program, CFD modeling was used to predict the gas compositions that will exist throughout and along the walls of air-fired and oxy-fired boilers operating with low to high sulfur coals. Test coupons of boiler tube materials were coated with deposits representative of those coals and exposed to the CFD predicted flue gases for up to 1000 hours. The tests were conducted in electric tube furnaces using oxy-combustion and air-fired flue gases synthesized from pressurized cylinders. Following exposure, the test coupons were evaluated to determine the total metal wastage experienced under air and oxy-combustions conditions and materials recommendations were made. Similar to air-fired operation, oxy-combustion corrosion rates were found to vary with the boiler material, test temperature, deposit composition, and gas composition. Despite this, comparison of air-fired and oxy-fired corrosion rates showed that oxy-firing rates were, for the most part, similar to, if not lower than those of air-firing; this finding applied to the seven furnace waterwall materials (wrought and weld overlay) and the ten superheater/reheater materials (wrought and weld overlay) that were tested. The results of the laboratory oxy-combustion tests, which are based on a maximum bulk flue gas SO2 level of 3200 ppmv (wet) / 4050 ppmv (dry), suggest that, from a corrosion standpoint, the materials used in conventional subcritical and supercritical, air-fired boilers should also be suitable for oxy-combustion retrofits. Although the laboratory test results are encouraging, they are only the first step of a material evaluation process and it is recommended that follow-on corrosion tests be conducted in coal-fired boilers operating under oxy-combustion to provide longer term (one to two year

  4. Oxy-Combustion Boiler Material Development

    Energy Technology Data Exchange (ETDEWEB)

    Michael Gagliano; Andrew Seltzer; Hans Agarwal; Archie Robertson; Lun Wang

    2012-01-31

    Under U.S. Department of Energy Cooperative Agreement No. DE-NT0005262 Foster Wheeler North America Corp conducted a laboratory test program to determine the effect of oxy-combustion on boiler tube corrosion. In this program, CFD modeling was used to predict the gas compositions that will exist throughout and along the walls of air-fired and oxy-fired boilers operating with low to high sulfur coals. Test coupons of boiler tube materials were coated with deposits representative of those coals and exposed to the CFD predicted flue gases for up to 1000 hours. The tests were conducted in electric tube furnaces using oxy-combustion and air-fired flue gases synthesized from pressurized cylinders. Following exposure, the test coupons were evaluated to determine the total metal wastage experienced under air and oxy-combustions conditions and materials recommendations were made. Similar to air-fired operation, oxy-combustion corrosion rates were found to vary with the boiler material, test temperature, deposit composition, and gas composition. Despite this, comparison of air-fired and oxy-fired corrosion rates showed that oxy-firing rates were, for the most part, similar to, if not lower than those of air-firing; this finding applied to the seven furnace waterwall materials (wrought and weld overlay) and the ten superheater/reheater materials (wrought and weld overlay) that were tested. The results of the laboratory oxy-combustion tests, which are based on a maximum bulk flue gas SO{sub 2} level of 3200 ppmv (wet) / 4050 ppmv (dry), suggest that, from a corrosion standpoint, the materials used in conventional subcritical and supercritical, air-fired boilers should also be suitable for oxy-combustion retrofits. Although the laboratory test results are encouraging, they are only the first step of a material evaluation process and it is recommended that follow-on corrosion tests be conducted in coal-fired boilers operating under oxy-combustion to provide longer term (one to

  5. Synthesis of functional materials in combustion reactions

    Science.gov (United States)

    Zhuravlev, V. D.; Bamburov, V. G.; Ermakova, L. V.; Lobachevskaya, N. I.

    2015-12-01

    The conditions for obtaining oxide compounds in combustion reactions of nitrates of metals with organic chelating-reducing agents such as amino acids, urea, and polyvinyl alcohol are reviewed. Changing the nature of internal fuels and the reducing agent-to-oxidizing agent ratio makes possible to modify the thermal regime of the process, fractal dimensionality, morphology, and dispersion of synthesized functional materials. This method can be used to synthesize simple and complex oxides, composites, and metal powders, as well as ceramics and coatings. The possibilities of synthesis in combustion reactions are illustrated by examples of αand γ-Al2O3, YSZ composites, uranium oxides, nickel powder, NiO and NiO: YSZ composite, TiO2, and manganites, cobaltites, and aluminates of rare earth elements.

  6. Highly Enriched Uranium Metal Cylinders Surrounded by Various Reflector Materials

    International Nuclear Information System (INIS)

    Bernard Jones; J. Blair Briggs; Leland Monteirth

    2007-01-01

    A series of experiments was performed at Los Alamos Scientific Laboratory in 1958 to determine critical masses of cylinders of Oralloy (Oy) reflected by a number of materials. The experiments were all performed on the Comet Universal Critical Assembly Machine, and consisted of discs of highly enriched uranium (93.3 wt.% 235U) reflected by half-inch and one-inch-thick cylindrical shells of various reflector materials. The experiments were performed by members of Group N-2, particularly K. W. Gallup, G. E. Hansen, H. C. Paxton, and R. H. White. This experiment was intended to ascertain critical masses for criticality safety purposes, as well as to compare neutron transport cross sections to those obtained from danger coefficient measurements with the Topsy Oralloy-Tuballoy reflected and Godiva unreflected critical assemblies. The reflector materials examined in this series of experiments are as follows: magnesium, titanium, aluminum, graphite, mild steel, nickel, copper, cobalt, molybdenum, natural uranium, tungsten, beryllium, aluminum oxide, molybdenum carbide, and polythene (polyethylene). Also included are two special configurations of composite beryllium and iron reflectors. Analyses were performed in which uncertainty associated with six different parameters was evaluated; namely, extrapolation to the uranium critical mass, uranium density, 235U enrichment, reflector density, reflector thickness, and reflector impurities. In addition to the idealizations made by the experimenters (removal of the platen and diaphragm), two simplifications were also made to the benchmark models that resulted in a small bias and additional uncertainty. First of all, since impurities in core and reflector materials are only estimated, they are not included in the benchmark models. Secondly, the room, support structure, and other possible surrounding equipment were not included in the model. Bias values that result from these two simplifications were determined and associated

  7. Combustion

    CERN Document Server

    Glassman, Irvin

    1997-01-01

    This Third Edition of Glassman's classic text clearly defines the role of chemistry, physics, and fluid mechanics as applied to the complex topic of combustion. Glassman's insightful introductory text emphasizes underlying physical and chemical principles, and encompasses engine technology, fire safety, materials synthesis, detonation phenomena, hydrocarbon fuel oxidation mechanisms, and environmental considerations. Combustion has been rewritten to integrate the text, figures, and appendixes, detailing available combustion codes, making it not only an excellent introductory text but also an important reference source for professionals in the field. Key Features * Explains complex combustion phenomena with physical insight rather than extensive mathematics * Clarifies postulates in the text using extensive computational results in figures * Lists modern combustion programs indicating usage and availability * Relates combustion concepts to practical applications.

  8. Effects of backing board materials on wood combustion performance

    Science.gov (United States)

    Mathew J. Hagge; Kenneth M. Bryden; Mark A. Dietenberger

    2004-01-01

    Cone calorimeter tests show that backing board materials do not affect the ignition time, initial heat release rate, or the total heat released of combustion for redwood slabs. However, it has been observed that backing board materials alter combustion performance by altering the secondary heat release peak observed when the pyrolysis reaction front nears the unheated...

  9. Combustion synthesis of inorganic materials; Muki zairyo no nensho gose

    Energy Technology Data Exchange (ETDEWEB)

    Oyanagi, M. [Ryukoku University, Kyoto (Japan)

    1999-11-01

    Combustion synthesis of porous titan carbide is outlined. In combustion synthesis, exothermic chain reaction, which is induced by igniting at one point of the simple substance mixture, propagates the combustion wave, and the compound is synthesized, which can be sintered by it. By this method, to this day intermetallic compounds, ceramics and high melting point composite materials have been synthesized, and synthetics can be made compact by adding pressure during or just after the reaction. Recently, applying the induction heating jointly, preheating before the reaction and heat treatment after the reaction can be controlled, accordingly, many high melting point inorganic compounds and composite materials can be made by combustion synthesis under pressure. (NEDO)

  10. Co-combustion of waste materials using fluidized bed technology

    Energy Technology Data Exchange (ETDEWEB)

    M. Lopes; I. Gulyurtlu; P. Abelha; T. Crujeira; D. Boavida; I. Cabrita [INETI-DEECA, Lisbon (Portugal)

    2004-07-01

    There is growing interest in using renewable fuels in order to sustain the CO{sub 2} accumulation. Several waste materials can be used as coal substitutes as long as they contain significant combustible matter, as for example MSW and sewage sludge. Besides the outcome of the energetic valorization of such materials, combustion must be regarded as a pre-treatment process, contributing to the safe management of wastes. Landfilling is an expensive management option and requires a previous destruction of the organic matter present in residues, since its degradation generates greenhouse gases and produces acidic organic leachates. Fluidized bed combustion is a promising technology for the use of mixtures of coal and combustible wastes. This paper presents INETI's experience in the co-combustion of coal with this kind of residues performed in a pilot fluidized bed. Both the RDF (from MSW and sewage sludge) and sewage sludge combustion problems were addressed, relating the gaseous emissions, the behaviour of metals and the leachability of ashes and a comparison was made between co-combustion and mono-combustion in order to verify the influence of the utilization of coal. 9 refs., 1 fig., 3 tabs.

  11. Optimization of Surrounding Reflector Material for Hyb-WT

    International Nuclear Information System (INIS)

    Tariq Siddique, M.; Hong, Song Hee; Kim, Myung Hyun

    2013-01-01

    The choice of reflector material is crucial for fusion and hybrid reactors as it was for the fission reactors. Multiple reflector materials were studied for pure fusion blanket design. The purpose of reflector in fusion blanket is to enhance the tritium breeding ratio (TBR). In fusion fission hybrid blanket the roll of reflector is slightly changed as it include the fission core and the performance of fission core also needs to be optimized and evaluated with the choice of reflector material, along with the enhancement of TBR. The performance parameters of Hyb-WT are significantly influenced by the choice of reflector material. TiC is best for TRU transmutation, TBR and reduced the neutron wall loading and graphite is best for FP transmutation. Strategy of multi reflector materials gives the best TRU and FP transmutation performance and also enhanced TBR with reduced neutron wall loading and it is a better choice for Hyb-WT reflector. The neutron flux is primarily dominated by the fission neutrons

  12. Sulfur Release from Cement Raw Materials during Solid Fuel Combustion

    DEFF Research Database (Denmark)

    Nielsen, Anders Rooma; Larsen, Morten B.; Glarborg, Peter

    2011-01-01

    During combustion of solid fuels in the material inlet end of cement rotary kilns, local reducing conditions can occur and cause decomposition of sulfates from cement raw materials. Decomposition of sulfates is problematic because it increases the gas-phase SO2 concentration, which may cause...... deposit formation in the kiln system. SO2 release from cement raw materials during combustion of solid fuels has been studied experimentally in a high temperature rotary drum. The fuels were tire rubber, pine wood, petcoke, sewage sludge, and polypropylene. The SO2 release from the raw materials...

  13. Bursting Bubbles from Combustion of Thermoplastic Materials in Microgravity

    Science.gov (United States)

    Butler, K. B.

    1999-01-01

    Many thermoplastic materials in common use for a wide range of applications, including spacecraft, develop bubbles internally as they burn due to chemical reactions taking place within the bulk. These bubbles grow and migrate until they burst at the surface, forceably ejecting volatile gases and, occasionally, molten fuel. In experiments in normal gravity, Kashiwagi and Ohlemiller observed vapor jets extending a few centimeters from the surface of a radiatively heated polymethylmethacrylate (PMMA) sample, with some molten material ejected into the gas phase. These physical phenomena complicated the combustion process considerably. In addition to the non-steady release of volatiles, the depth of the surface layer affected by oxygen was increased, attributed to the roughening of the surface by bursting events. The ejection of burning droplets in random directions presents a potential fire hazard unique to microgravity. In microgravity combustion experiments on nylon Velcro fasteners and on polyethylene wire insulation, the presence of bursting fuel vapor bubbles was associated with the ejection of small particles of molten fuel as well as pulsations of the flame. For the nylon fasteners, particle velocities were higher than 30 cm/sec. The droplets burned robustly until all fuel was consumed, demonstrating the potential for the spread of fire in random directions over an extended distance. The sequence of events for a bursting bubble has been photographed by Newitt et al.. As the bubble reaches the fluid surface, the outer surface forms a dome while the internal bubble pressure maintains a depression at the inner interface. Liquid drains from the dome until it breaks into a cloud of droplets on the order of a few microns in size. The bubble gases are released rapidly, generating vortices in the quiescent surroundings and transporting the tiny droplets. The depression left by the escaping gases collapses into a central jet, which rises with a high velocity and may

  14. Prevention of spontaneous combustion of backfilled plant waste material.

    CSIR Research Space (South Africa)

    Adamski, SA

    2003-06-01

    Full Text Available Since Grootegeluk Coal Mine commenced operation in 1980 all plant discards and inter-burden material have been stacked on discards dumps, a practice that has led to the spontaneous combustion of the waste material on these dumps. From 1980 to 1988...

  15. Role of coal combustion products in sustainable construction materials

    Energy Technology Data Exchange (ETDEWEB)

    Naik, T.R.; Siddique, R.; Vaniker, S. [University of Wisconsin-Milwaukee, Milwaukee, WI (USA). UWM Center for Products Utilization, College of Engineering and Applied Science

    2003-07-01

    The paper describes various coal combustion products, CCPs produced in the process of power generation. These include fly ash, bottom ash, boiler slag and flue gas desulfurization products. Typical test protocol used for testing, analysis and evaluation of CCPs, as well as the current best recycling use options for these materials are discussed. Materials, productions, properties, and potential applications in the manufacture of emerging materials for sustainable construction, as well as environmental impact are also briefly discussed. 47 refs., 16 figs., 8 tabs.

  16. Chemical Pollution from Combustion of Modern Spacecraft Materials

    Science.gov (United States)

    Mudgett, Paul D.

    2013-01-01

    Fire is one of the most critical contingencies in spacecraft and any closed environment including submarines. Currently, NASA uses particle based technology to detect fires and hand-held combustion product monitors to track the clean-up and restoration of habitable cabin environment after the fire is extinguished. In the future, chemical detection could augment particle detection to eliminate frequent nuisance false alarms triggered by dust. In the interest of understanding combustion from both particulate and chemical generation, NASA Centers have been collaborating on combustion studies at White Sands Test Facility using modern spacecraft materials as fuels, and both old and new technology to measure the chemical and particulate products of combustion. The tests attempted to study smoldering pyrolysis at relatively low temperatures without ignition to flaming conditions. This paper will summarize the results of two 1-week long tests undertaken in 2012, focusing on the chemical products of combustion. The results confirm the key chemical products are carbon monoxide (CO), hydrogen cyanide (HCN), hydrogen fluoride (HF) and hydrogen chloride (HCl), whose concentrations depend on the particular material and test conditions. For example, modern aerospace wire insulation produces significant concentration of HF, which persists in the test chamber longer than anticipated. These compounds are the analytical targets identified for the development of new tunable diode laser based hand-held monitors, to replace the aging electrochemical sensor based devices currently in use on the International Space Station.

  17. Semiconductor properties of solid combustible materials

    Energy Technology Data Exchange (ETDEWEB)

    Patrushev, S G; Kamneva, A I; Galaktionov, S S; Aleksandrov, I V

    1980-01-01

    The photoelectric e.m.f. with p-type conductivity and the photodielectric effect were examined in specimens of a number of coals and coal microcomponents. These effects are largest in hard coal fusinite. Photosensitive materials show increased dielectric losses in the dark. The authors determined charge carrier mobility, and showed that the charge carriers are injected by oxygen in the presence of an electrolyte, and that the coals oxidise as in electrochemical corrosion.

  18. Use of Thermoanalytic Methods in the Evaluation of Combusted Materials

    Directory of Open Access Journals (Sweden)

    František Krepelka

    2006-12-01

    Full Text Available The paper describes possibilities of using thermoanalytic methods for the evaluation and comparison of materials designed for a direct combustion. Differential thermal analysis (DTA and thermogravimetric analysis (TGA were both used in the evaluation. The paper includes a description of methods of data processing from analyses for the purposes of comparison of used materials regarding their heating values. The following materials were analysed in the experiments: wooden coal of objectional grain size, fly ash from heating plant exhaust funnels, dendromass waste: spruce sawdust, micro-briquettes of spruce sawdust and fly-ash combined.

  19. Cermet materials prepared by combustion synthesis and metal infiltration

    Science.gov (United States)

    Holt, Joseph B.; Dunmead, Stephen D.; Halverson, Danny C.; Landingham, Richard L.

    1991-01-01

    Ceramic-metal composites (cermets) are made by a combination of self-propagating high temperature combustion synthesis and molten metal infiltration. Solid-gas, solid-solid and solid-liquid reactions of a powder compact produce a porous ceramic body which is infiltrated by molten metal to produce a composite body of higher density. AlN-Al and many other materials can be produced.

  20. Combustion

    CERN Document Server

    Glassman, Irvin

    1987-01-01

    Combustion, Second Edition focuses on the underlying principles of combustion and covers topics ranging from chemical thermodynamics and flame temperatures to chemical kinetics, detonation, ignition, and oxidation characteristics of fuels. Diffusion flames, flame phenomena in premixed combustible gases, and combustion of nonvolatile fuels are also discussed. This book consists of nine chapters and begins by introducing the reader to heats of reaction and formation, free energy and the equilibrium constants, and flame temperature calculations. The next chapter explores the rates of reactio

  1. Combustion

    CERN Document Server

    Glassman, Irvin

    2008-01-01

    Combustion Engineering, a topic generally taught at the upper undergraduate and graduate level in most mechanical engineering programs, and many chemical engineering programs, is the study of rapid energy and mass transfer usually through the common physical phenomena of flame oxidation. It covers the physics and chemistry of this process and the engineering applications-from the generation of power such as the internal combustion automobile engine to the gas turbine engine. Renewed concerns about energy efficiency and fuel costs, along with continued concerns over toxic and particulate emissions have kept the interest in this vital area of engineering high and brought about new developments in both fundamental knowledge of flame and combustion physics as well as new technologies for flame and fuel control. *New chapter on new combustion concepts and technologies, including discussion on nanotechnology as related to combustion, as well as microgravity combustion, microcombustion, and catalytic combustion-all ...

  2. Some relevant parameters for assessing fire hazards of combustible mine materials using laboratory scale experiments.

    Science.gov (United States)

    Litton, Charles D; Perera, Inoka E; Harteis, Samuel P; Teacoach, Kara A; DeRosa, Maria I; Thomas, Richard A; Smith, Alex C

    2018-04-15

    When combustible materials ignite and burn, the potential for fire growth and flame spread represents an obvious hazard, but during these processes of ignition and flaming, other life hazards present themselves and should be included to ensure an effective overall analysis of the relevant fire hazards. In particular, the gases and smoke produced both during the smoldering stages of fires leading to ignition and during the advanced flaming stages of a developing fire serve to contaminate the surrounding atmosphere, potentially producing elevated levels of toxicity and high levels of smoke obscuration that render the environment untenable. In underground mines, these hazards may be exacerbated by the existing forced ventilation that can carry the gases and smoke to locations far-removed from the fire location. Clearly, materials that require high temperatures (above 1400 K) and that exhibit low mass loss during thermal decomposition, or that require high heat fluxes or heat transfer rates to ignite represent less of a hazard than materials that decompose at low temperatures or ignite at low levels of heat flux. In order to define and quantify some possible parameters that can be used to assess these hazards, small-scale laboratory experiments were conducted in a number of configurations to measure: 1) the toxic gases and smoke produced both during non-flaming and flaming combustion; 2) mass loss rates as a function of temperature to determine ease of thermal decomposition; and 3) mass loss rates and times to ignition as a function of incident heat flux. This paper describes the experiments that were conducted, their results, and the development of a set of parameters that could possibly be used to assess the overall fire hazard of combustible materials using small scale laboratory experiments.

  3. Means of regulating combustible materials and products in external walls

    Directory of Open Access Journals (Sweden)

    Mikkola Esko

    2016-01-01

    Full Text Available This report presents proposals for defining means of regulating the use of combustible materials and products in external walls. Required protections are based on the quantities of fire loads and their contribution to fire development. The study is based on life safety and protection of property priorities taking into account reaction to fire classes related to different types of fire loads and fire compartmentation requirements of the adjacent spaces of concern. The proposals include the following main principles in relation to fire-separation requirements: In case of internal fire exposure the protective structure for combustible building parts needs to meet at least half of the fire-separating requirement for the compartment of concern. In case of external fire exposure the protection time requirement can be 15 minutes less than for the internal protection. The proposals are applicable for residential buildings and offices. In case of buildings with longer evacuation times more stringent requirement levels may be considered. For verification of protection performance of fire loads it is proposed to use existing standardized test methods (fire protection ability (K classes and fire-separating function (EI classes validated methods of calculation and/or large scale fire testing.

  4. Combustion and Ignition Studies of Nanocomposite Energetic Materials

    Science.gov (United States)

    2010-12-14

    Characterization of a gas burner to simulate a propellant flame and evaluate aluminum particle combustion,” M. Jackson, M. L. Pantoya and W. Gill, Combustion...of a gas burner to simulate a propellant flame and evaluate aluminum particle combustion,” M. Jackson, M. L. Pantoya and W. Gill, Combustion and...changes in parameters such as particle size. The LFA measures these properties for bulk powders, consolidated pellets or even liquid mediums and is

  5. Ignition Delay of Combustible Materials in Normoxic Equivalent Environments

    Science.gov (United States)

    McAllister, Sara; Fernandez-Pello, Carlos; Ruff, Gary; Urban, David

    2009-01-01

    Material flammability is an important factor in determining the pressure and composition (fraction of oxygen and nitrogen) of the atmosphere in the habitable volume of exploration vehicles and habitats. The method chosen in this work to quantify the flammability of a material is by its ease of ignition. The ignition delay time was defined as the time it takes a combustible material to ignite after it has been exposed to an external heat flux. Previous work in the Forced Ignition and Spread Test (FIST) apparatus has shown that the ignition delay in the currently proposed space exploration atmosphere (approximately 58.6 kPa and32% oxygen concentration) is reduced by 27% compared to the standard atmosphere used in the Space Shuttle and Space Station. In order to determine whether there is a safer environment in terms of material flammability, a series of piloted ignition delay tests using polymethylmethacrylate (PMMA) was conducted in the FIST apparatus to extend the work over a range of possible exploration atmospheres. The exploration atmospheres considered were the normoxic equivalents, i.e. reduced pressure conditions with a constant partial pressure of oxygen. The ignition delay time was seen to decrease as the pressure was reduced along the normoxic curve. The minimum ignition delay observed in the normoxic equivalent environments was nearly 30% lower than in standard atmospheric conditions. The ignition delay in the proposed exploration atmosphere is only slightly larger than this minimum. Interms of material flammability, normoxic environments with a higher pressure relative to the proposed pressure would be desired.

  6. Safe Handling and Use of Flammable and Combustible Materials. Module SH-30. Safety and Health.

    Science.gov (United States)

    Center for Occupational Research and Development, Inc., Waco, TX.

    This student module on safe handling and use of flammable and combustible materials is one of 50 modules concerned with job safety and health. This module introduces the student to the hazards of flammable and combustible materials and the measures necessary to control those hazards. Following the introduction, 14 objectives (each keyed to a page…

  7. Enhancement of thermal neutron self-shielding in materials surrounded by reflectors

    International Nuclear Information System (INIS)

    Cornelia Chilian; Gregory Kennedy

    2012-01-01

    Materials containing from 41 to 1124 mg chlorine and surrounded by polyethylene containers of various thicknesses, from 0.01 to 5.6 mm, were irradiated in a research reactor neutron spectrum and the 38 Cl activity produced was measured as a function of polyethylene reflector thickness. For the material containing the higher amount of chlorine, the 38 Cl specific activity decreased with increasing reflector thickness, indicating increased neutron self-shielding. It was found that the amount of neutron self-shielding increased by as much as 52% with increasing reflector thickness. This is explained by neutrons which have exited the material subsequently reflecting back into it and thus increasing the total mean path length in the material. All physical and empirical models currently used to predict neutron self-shielding have ignored this effect and need to be modified. A method is given for measuring the adjustable parameter of a self-shielding model for a particular sample size and combination of neutron reflectors. (author)

  8. Fast Reacting Nano Composite Energetic Materials: Synthesis and Combustion Characterization

    Science.gov (United States)

    2015-08-24

    nanoenergetic composites finding extensive use in ordnance and industrial applications, because of its high heat of combustion (~32 kJ/g) (S. H. Fischer ...2011. Farley, Cory. "Reactions of Aluminum with Halogen Containing Oxides." Dissertation. Lubbock, TX, May 2013. Gesner, Jeff , Michelle Pantoya, and...characteristics of novel hybrid nanoenergetic formulations." Combustion and Flame 158 (2011): 964- 978. S. H. Fischer , M. C. Grubelich. "Theoretical

  9. Technique for in-place welding of aluminum backed up by a combustible material

    Science.gov (United States)

    Spagnuolo, A. C.

    1971-01-01

    Welding external aluminum jacket, tightly wrapped around inner layer of wood composition fiberboard, in oxygen free environment prevents combustion and subsequent damage to underlying fiberboard. Technique also applies to metal cutting in similar assemblies without disassembly to remove combustible materials from welding heat proximity.

  10. Combustion of crude oil sludge containing naturally occurring radioactive material

    International Nuclear Information System (INIS)

    Mohamad Puad Abu; Muhd Noor Muhd Yunus; Shamsuddin, A.H.; Sopian, K.

    2000-01-01

    The characteristics of crude oil sludge fi-om the crude oil terminal are very unique because it contains both heavy metals and also Naturally Occurring Radioactive Material (NORM). As a result, the Department of Environmental (DOE) and the Atomic Energy Licensing Board (AELB) considered it as Scheduled Wastes and Low Level Radioactive Waste (LLRW) respectively. As a Scheduled Wastes, there is no problem in dealing with the disposal of it since there already exist a National Center in Bukit Nanas to deal with this type of waste. However, the Center could not manage this waste due to the presence of NORM by which the policy regarding the disposal of this kind of waste has not been well established. This situation is unclear to certain parties, especially with respect to the relevant authorities having final jurisdiction over the issue as well as the best practical method of disposal of this kind of waste. Existing methods of treatment viewed both from literature and current practice include that of land farming, storing in plastic drum, re-injection into abandoned oil well, recovery, etc., found some problems. Due to its organic nature, very low level in radioactivity and the existence of a Scheduled Waste incineration facility in Bukit Nanas, there is a potential to treat this sludge by using thermal treatment technology. However, prior to having this suggestion to be put into practice, there are issues that need to be addressed. This paper attempts to discuss the potentials and the related issues of combusting crude oil sludge based on existing experimental data as well as mathematical modeling

  11. Measured and Predicted Neutron Flux Distributions in a Material Surrounding a Cylindrical Duct

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, J; Sandlin, R

    1966-03-15

    The radial fast neutron flux attenuations in the material (iron) surrounding ducts of diameters 7, 9, and 15 cm and total duct length of about 1.5 m have been investigated with and without neutron scattering cans filled with D{sub 2}O in the duct. Experimentally the problem was solved by the use of foil activation techniques. Theoretically it was attacked by, in the first place, a Monte Carlo program specially written for this purpose and utilizing an importance sampling technique. In the second place non- and single-scattering removal flux codes were tried, and also simple hand calculations. The Monte Carlo results accounted well for the fast flux attenuation, while the non- and single-scattering methods overestimated the attenuation generally by a factor of 10 or less. Simple hand calculations using three empirical parameters could be fitted to the measured data within a factor of 1.2 - 1.3 at penetration depths greater than 3 - 4 cm. The distribution of the D{sub 2}O-scattered flux could well be described in terms of single scattering.

  12. Fluidized bed combustion bottom ash: A better and alternative geo-material resource for construction.

    Science.gov (United States)

    Mandal, A K; Paramkusam, Bala Ramudu; Sinha, O P

    2018-04-01

    Though the majority of research on fly ash has proved its worth as a construction material, the utility of bottom ash is yet questionable due to its generation during the pulverized combustion process. The bottom ash produced during the fluidized bed combustion (FBC) process is attracting more attention due to the novelty of coal combustion technology. But, to establish its suitability as construction material, it is necessary to characterize it thoroughly with respect to the geotechnical as well as mineralogical points of view. For fulfilling these objectives, the present study mainly aims at characterizing the FBC bottom ash and its comparison with pulverized coal combustion (PCC) bottom ash, collected from the same origin of coal. Suitability of FBC bottom ash as a dike filter material in contrast to PCC bottom ash in replacing traditional filter material such as sand was also studied. The suitability criteria for utilization of both bottom ash and river sand as filter material on pond ash as a base material were evaluated, and both river sand and FBC bottom ash were found to be satisfactory. The study shows that FBC bottom ash is a better geo-material than PCC bottom ash, and it could be highly recommended as an alternative suitable filter material for constructing ash dikes in place of conventional sand.

  13. Thermal conditions for stopping pyrolysis of forest combustible material and applications to firefighting

    Directory of Open Access Journals (Sweden)

    Zhdanova Alena O.

    2017-01-01

    Full Text Available Five models describing heat transfer during evaporation of the water sprayed over the forest to stop fires and to cool down the pyrolysis of the bio- top layer are established and investigated by a parametric approach. It aims to improve the understanding of the behaviour and the properties of the forest combustible material. A mathematical description of forest combustible material surfaces (needles of pine and fir-tree, leaves of birch is established. The characteristic time, td, to cool down the forest combustible material layer below the temperature of the onset of the pyrolysis is the important parameter investigated in the present work. The effective conditions were determined allowing to reach the shortest td and the lowest consumption of e. g. water to be dropped.

  14. 75 FR 17111 - Hazardous Materials Regulations: Combustible Liquids

    Science.gov (United States)

    2010-04-05

    ... the probability and quantity of a hazardous material release. Under the HMR, hazardous materials are... present during transportation. The HMR specify appropriate packaging and handling requirements for... hazardous materials in commerce. During our regulatory review process, we look for opportunities that may...

  15. Method and apparatus for measuring neutron characteristics of material surrounding a borehole

    International Nuclear Information System (INIS)

    Hopkinson, E.C.

    1983-01-01

    This invention relates to methods and apparatus for determining the macroscopic thermal neutron absorption cross section of the formations surrounding a borehole as determined by radiation measurements using optimized measurement intervals. A measurement of the decline of the thermal neutron population in the formation is derived by counting the detected radiation within a first pair of measurement intervals occurring at a fixed time after the neutron burst. A ratio of the two counting rates provides the rate of change over the selected time interval. The counting ratio is converted into a natural logarithm representative of the Sigma calculation

  16. Method and apparatus for measuring neutron characteristics of material surrounding a borehole

    International Nuclear Information System (INIS)

    Randall, R.R.

    1983-01-01

    A method for logging the formations surrounding an earth borehole, comprising: pulsedly irradiating said formations with discrete bursts form a source of high energy neutrons; detecting radiations emanating from said irradiated formations at a detector spaced from said source; measuring said detected radiations during first and second time intervals following a burst from said source; generating time-separated electrical pulses indicative of said detected radiations during a third fixed time duration interval following a subsequent burst from said sources; and controlling automatically the starting time of said third measurement interval in accordance with the said measurement from said first and second time intervals

  17. Effect of density on forward and upward smoldering combustion of cellulosic material

    Science.gov (United States)

    Veronica, Sherly; Putri, R. H.; Fitriani, F.; Ramadhan, M. L.; Riki, M.; Reynaldo, S.; Imran, F. A.; Nugroho, Yulianto S.

    2017-03-01

    Smoldering is a slow, flameless and the most persistent type of combustion. Wildland fire or ground fire is an example of smoldering combustion which has become one of the most important issue in Indonesia and no effective solution has been found to solve this phenomenon yet. The organic materials contained in peatland can potentially become a flammable fuel with the presence of a trigger for wildland fire. In this experimental work tobacco material was used to study smoldering phenomenon. The relation between material density with temperature distribution and mass loss rate are conducted in the experiment. The transmissivity of the smoke produced by the smoldering combustion will also be analyzed. Experiments are carried out for the material density ranging from 0.12 - 0.2 g/cm3. The result showed that smoldering combustion are affected by density, due to the allowance of airflow and heat propagation. The result showed that material bed with the lowest density of 0.12 g/cm3 has the slowest smoldering velocity and mass loss rate while the material bed with the highest density of 0.2 g/cm3 has the fastest smoldering velocity and mass loss rate. The smoke took a longer period time to reach the bed surface at higher bed density.

  18. A two-dimensional analytical subthreshold behavior model for junctionless dual-material cylindrical surrounding-gate MOSFETs

    International Nuclear Information System (INIS)

    Li Cong; Zhuang Yi-Qi; Zhang Li; Jin Gang

    2014-01-01

    A two-dimensional analytical subthreshold behavior model for junctionless dual-material cylindrical surrounding-gate (JLDMCSG) metal-oxide-semiconductor field-effect transistors (MOSFETs) is proposed. It is derived by solving the two-dimensional Poisson's equation in two continuous cylindrical regions with any simplifying assumption. Using this analytical model, the subthreshold characteristics of JLDMCSG MOSFETs are investigated in terms of channel electrostatic potential, horizontal electric field, and subthreshold current. Compared to junctionless single-material cylindrical surrounding-gate MOSFETs, JLDMCSG MOSFETs can effectively suppress short-channel effects and simultaneously improve carrier transport efficiency. It is found that the subthreshold current of JLDMCSG MOSFETs can be significantly reduced by adopting both a thin oxide and thin silicon channel. The accuracy of the analytical model is verified by its good agreement with the three-dimensional numerical simulator ISE TCAD

  19. Ignition delay of combustible materials in normoxic equivalent environments

    Science.gov (United States)

    Sara McAllister; Carlos Fernandez-Pello; Gary Ruff; David Urban

    2009-01-01

    Material flammability is an important factor in determining the pressure and composition (fraction of oxygen and nitrogen) of the atmosphere in the habitable volume of exploration vehicles and habitats. The method chosen in this work to quantify the flammability of a material is by its ease of ignition. The ignition delay time was defined as the time it takes a...

  20. Study of dimensional changes during redox cycling of oxygen carrier materials for chemical looping combustion

    NARCIS (Netherlands)

    Fossdal, A.; Darell, O.; Lambert, A.; Schols, E.; Comte, E.; Leenman, R.N.; Blom, R.

    2015-01-01

    Dimensional and phase changes of four candidate oxygen carrier materials for chemical looping combustion are investigated by dilatometry and high-temperature X-ray diffraction during four redox cycles. NiO/Ni2AlO4 does not exhibit significant dimensional changes during cycling, and it is shown that

  1. 29 CFR 1910.107 - Spray finishing using flammable and combustible materials.

    Science.gov (United States)

    2010-07-01

    ... drying apparatus and electrical connections and wiring thereto shall not be located within spray... apparatus, the drying apparatus, and the ventilating system of the spray enclosure shall be equipped with... 29 Labor 5 2010-07-01 2010-07-01 false Spray finishing using flammable and combustible materials...

  2. Flow evaluation of the leaching hazardous materials from spent nickel-cadmium batteries discarded in different water surroundings.

    Science.gov (United States)

    Guo, Xingmei; Song, Yan; Nan, Junmin

    2018-02-01

    The leaching characteristics of hazardous materials from Ni-Cd batteries immersed in four typical water samples, i.e., water with NaCl, river water, tap water, and deionized water, were investigated to evaluate the potential environmental harm of spent Ni-Cd batteries in the water surroundings. It is shown that four water surroundings all could leach hazardous materials from the Ni-Cd batteries. The water with NaCl concentration of 66.7 mg L -1 had the highest leaching ability, the hazardous materials were leached after only approximately 50 days (average time, with a standard deviation of 4.1), while less than 100 days were needed in the others. An electrochemical corrosion is considered to be the main leaching mechanism leading to battery breakage, while the dissolution-deposition process and the powder route result in the leakage and transference of nickel and cadmium materials from the electrodes. The anions, i.e., SO 4 2- and Cl - , and dissolved oxygen in water were demonstrated to be the vital factors that influence the leaching processes. Thus, it is proposed that spent Ni-Cd batteries must be treated properly to avoid potential danger to the environment.

  3. Combustion synthesis of advanced materials. [using in-situ infiltration technique

    Science.gov (United States)

    Moore, J. J.; Feng, H. J.; Perkins, N.; Readey, D. W.

    1992-01-01

    The combustion synthesis of ceramic-metal composites using an in-situ liquid infiltration technique is described. The effect of varying the reactants and their stoichiometry to provide a range of reactant and product species i.e. solids, liquids and gases, with varying physical properties e.g. thermal conductivity, on the microstructure and morphology of synthesized products is also described. Alternatively, conducting the combustion synthesis reaction in a reactive gas environment is also discussed, in which advantages can be gained from the synergistic effects of combustion synthesis and vapor phase transport. In each case, the effect of the presence or absence of gravity (density) driven fluid flow and vapor transport is discussed as is the potential for producing new and perhaps unique materials by conducting these SHS reactions under microgravity conditions.

  4. Thermal interactions of a molten core debris pool with surrounding structural materials

    International Nuclear Information System (INIS)

    Baker, L. Jr.; Cheung, F.B.; Farhadieh, R.; Stein, R.P.; Gabor, J.D.; Bingle, J.D.

    1979-01-01

    Analytical and experimental results on individual aspects of the overall problem of the interaction of a large mass of LMFBR core debris with concrete or other materials are reviewed. Results of recent heat transfer experiments with molten UO 2 have indicated the importance of internal thermal radiation and methods to take account of this are developed. Effects of gas release and density difference are considered. The GROWS-2 Code is used to illustrate the effects of various assumptions

  5. Considerations on valorization of biomass origin materials in co-combustion with coal in fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    I. Gulyurtlu; P. Abelha; H. Lopes; A. Crujeira; I. Cabrita [DEECA-INETI, Lisbon (Portugal)

    2007-07-01

    Co-combustion of biomass materials with coal is currently gaining increasing importance, in order to meet the targets on greenhouse gas emissions, defined in the Kyoto protocol. Co-firing of coal with biomass materials could be the short-term solution in reducing CO{sub 2} emissions from power stations. The work undertaken studied co-firing of meat and bone meal (MBM), olive cake and straw pellets with bituminous coals from Colombia (CC) and Poland (PC), which are commonly used in European power stations. The co-combustion studies were carried out on the pilot fluidized bed installation of INETI. Gaseous pollutants and solid concentration in flue gases and ashes from different locations were monitored. Results obtained indicate that the co-feeding of biomass materials did not present any problem and ensured stable combustion conditions and high efficiency. However, for temperatures above 800{sup o}C, bed agglomeration could be observed for all biomass species studied. Most of the combustion of biomass material, contrary to that of coal, was observed to take place in the riser where the temperature was as high as 150-250{sup o}C above that of the bed. SO{sub 2} and NOx levels were found to be lower. The emissions of dioxins could be considerable with fuels with high Cl as is the case with straw. However, mixing of fuels with high S content could lead to a strong reduction in dioxin emissions. Ashes produced from biomass combustion may be considered for further reutilization or landfilling. Other options depend on their characteristics, chemical composition and leaching behaviour. This was evaluated in this study.

  6. Combustion synthesis of TiC-based materials: Mechanisms, densification, and properties

    International Nuclear Information System (INIS)

    LaSalvia, J.C.; Meyers, M.A.

    1995-01-01

    The micromechanisms involved in the combustion synthesis of a Ti-C-Ni-Mo mixture resulting in the formation of a TiC-based composite were examined using the combustion wave quenching technique developed by Rogachev et al. At the micron level, the main reaction occurs at the interface between a Ti-Ni-C melt and C particles, resulting in the formation of a solid TiC x layer on the C particles. This layer undergoes a successive process of rapid growth and decomposition into TiC x spherules until all of the C particle is consumed. This mechanism is consistent with the apparent activation energy (E = 100 kJ/mol) for the process obtained from a macrokinetic investigation of the system. The apparent uniformity in size (d = 1 μm) of the TiC x spherules upon formation indicates a critical condition in the stability of the energetics involved in the process. These TiC x spherules undergo growth due to Ostwald ripening and coalescence mechanisms resulting in a final apparent size of 2.5 μm. For the compositions investigated, the addition of Mo did not affect either the micromechanisms or macrokinetics of the combustion synthesis process. Densification of the porous body after the combustion synthesis process can be carried out while it is still in a easily deformable state. The highly porous body is densified by a combination of fracture (communition), plastic deformation, and sintering. The mechanisms are identified for the case of combustion synthesized TiC. Mechanical properties and microstructures of a number of materials (e.g. TiC, TiB 2 , Al 2 O 3 -TiB 2 , TiB 2 -SiC, TiC-Ni-Mo) produced by combustion synthesis combined with a high-velocity forging step are reviewed

  7. THE REACTION TO FIRE TEST FOR FIRE RETARDANT AND FOR COMBUSTIBLE MATERIAL

    Directory of Open Access Journals (Sweden)

    Adelaida FANFAROVÁ

    2016-12-01

    Full Text Available Currently the natural materials become popular building material for houses, buildings and recreational property. The risk of fires in residential timber construction or eco houses cannot be completely ruled out, therefore there is a need for proper and correct implementing preventive measures and application of all available solutions, which may reduce the risk of fire as far as possible, to slow down the combustion process, to protect the life of people, animals and also the building itself until arrival members of the Fire and Rescue Services. Fireproofing of combustible materials is a specific area of fire protection. For scientific research as well as for real-life practice, not only their structural and physical properties, but also fire-technical characteristics are really important. The present researchers mostly focus on fire-retardant treatment of wood that is why the authors of this contribution focused on a different combustible material. This research article presents the experimental testing and examination of the reaction to fire test of the selected thermal insulation of hemp fiber that was impregnated by the selected fire retardant in laboratory conditions.

  8. Standard operating procedure for combustion of 14C - samples with OX-500 biological material oxidizer

    International Nuclear Information System (INIS)

    Nashriyah Mat.

    1995-01-01

    This procedure is for the purpose of safe operation of OX-500 biological material oxidizer. For ease of operation, the operation flow chart (including testing the system and sample combustion) and end of day maintenance flow chart were simplified. The front view, diagrams and switches are duly copied from operating manual. Steps on sample preparation are also included for biotic and a biotic samples. This operating procedure is subjected to future reviews

  9. Synthesis and characterization of a ferrous compound material obtained by combustion of ferroboron and ferrotitanium mixtures

    International Nuclear Information System (INIS)

    Bejar, M.A; Fuenzalida, J.L

    2008-01-01

    A ferrous compound material was synthesized in this work, by the air auto-combustion of mixtures of powdered ferroboron and ferrotitanium, compacted under pressures of 79 and 93 MPa and preheated to a temperature of about 1000 o C. The synthesized compounds were characterized by XRD analysis, and macro and micro-hardness tests. The formation of titanium diboride was found in all the synthesized test pieces (au)

  10. Utilization of stabilized municipal waste combustion ash residues as construction material

    International Nuclear Information System (INIS)

    Shieh, C.S.

    1992-01-01

    Stabilized municipal waste combustion (MWC) ash residues were investigated for their potential as construction material that can be beneficially used in terrestrial and marine environments. End-use products, such as patio stones, brick pavers, solid blocks, and reef units, were fabricated and tested for their engineering and chemical characteristics. engineering feasibility and environmental acceptability of using stabilized ash residues as construction material are discussed in this paper. Ash samples were collected from two mass-burn facilities and one refuse derived fuel (RDF) facility in Florida

  11. Process and unit for gasification of combustible material. Verfahren und Aggregat zur Vergasung brennbaren Gutes

    Energy Technology Data Exchange (ETDEWEB)

    Linneborn, J

    1987-05-21

    The invention refers to a process for the gasification of solid and combustible material in a moving bed and a unit in which this process can be carried out. By material to be gasified one means small material such as ground fossil coal and all organic substances such as wood, straw, husks and shells of fruit, to which sewage sludge can be added. The new process can be carried out, according to the invention, in a closed duct moved by vibration or shaking, in which the material or the ash produced moves from one end to the other by suitable vibration and comes into contact with round heat sources largely resistant to friction. This achieves rapid gasification of the material (at about 1000/sup 0/C) by convection and radiation.

  12. In vitro evaluation of resonance frequency analysis values to different implant contact ratio and stiffness of surrounding material.

    Science.gov (United States)

    Kwak, Mu-Seung; Kim, Seok-Gyu

    2013-11-01

    The present study was aimed to evaluate the influence of implant contact ratio and stiffness of implant-surrounding materials on the resonance frequency analysis (RFA) values. Seventy resin blocks that had the different amounts (100, 50, 30, 15%) of resin-implant contact (RIC) were fabricated. Ten silicone putty blocks with 100% silicone-implant contact were also made. The implants with Ø5.0 mm × 13.0 mm were placed on eighty specimen blocks. The RFA value was measured on the transducer that was connected to each implant by Osstell Mentor. Kruskal-Wallis and Scheffe's tests (α=.05) were done for statistical analysis. The control resin group with 100% RIC had the highest RFA value of 83.9, which was significantly different only from the resin group with 15% RIC among the resin groups. The silicone putty group with 100% contact had the lowest RFA value of 36.6 and showed statistically significant differences from the resin groups. Within the limitations of this in vitro study, there was no significant difference in the RFA values among the resin groups with different RIC's except when the RIC difference was more than 85%. A significant increase in the RFA value was observed related to the increase in stiffness of material around implant.

  13. Mechanochemical modification of the composition and structure of plant raw materials to control the combustion of alternative fuel

    Directory of Open Access Journals (Sweden)

    Bychkov Aleksey

    2017-01-01

    Full Text Available The possibilities of mechanochemistry in processing of renewable lignocellulose raw material into solid kinds of biofuel are demonstrated in this work. A review of lignocellulose raw materials promising for our country is presented. These raw materials include wastes from agriculture and forestry, and the biomass of rapidly growing plants. The physicochemical properties of lignocellulose materials with different delignification degrees were modeled with the help of the artificial mixtures of plant raw material with purified cellulose and lignin. The data illustrating the effect of disperse state and lignin content on the reactivity of the material in subsequent combustion are presented. The tests at the combustion bench with the thermal power up to 5 MW allowed determining the optimal combustion parameters for the obtained biofuel in the autothermal mode.

  14. Effect of plasma spraying modes on material properties of internal combustion engine cylinder liners

    Science.gov (United States)

    Timokhova, O. M.; Burmistrova, O. N.; Sirina, E. A.; Timokhov, R. S.

    2018-03-01

    The paper analyses different methods of remanufacturing worn-out machine parts in order to get the best performance characteristics. One of the most promising of them is a plasma spraying method. The mathematical models presented in the paper are intended to anticipate the results of plasma spraying, its effect on the properties of the material of internal combustion engine cylinder liners under repair. The experimental data and research results have been computer processed with Statistica 10.0 software package. The pare correlation coefficient values (R) and F-statistic criterion are given to confirm the statistical properties and adequacy of obtained regression equations.

  15. Coal combustion products in Europe valuable raw materials for the construction industry

    Energy Technology Data Exchange (ETDEWEB)

    Berg, W. vom; Feuerborn, H.J. [European Coal Combustion Products Association e.V., Essen (Germany)

    2005-07-01

    Coal combustion products (CCPs) are formed with the production of electricity in coal-fired power plants. The production of these CCPs has been increased by the years due to legal requirements for flue gas cleaning. The utilisation of CCPS is well is established in some European countries, based on long term experience and technical as well as environmental benefits. As CCPs are defined as waste materials by existing legislation the power industry has to handle the stigma put on the products and hamper the beneficial use. (orig.)

  16. Biomass waste carbon materials as adsorbents for CO2 capture under post-combustion conditions

    Directory of Open Access Journals (Sweden)

    Elisa M Calvo-Muñoz

    2016-05-01

    Full Text Available A series of porous carbon materials obtained from biomass waste have been synthesized, with different morphologies and structural properties, and evaluated as potential adsorbents for CO2 capture in post-combustion conditions. These carbon materials present CO2 adsorption capacities, at 25 ºC and 101.3 kPa, comparable to those obtained by other complex carbon or inorganic materials. Furthermore, CO2 uptakes under these conditions can be well correlated to the narrow micropore volume, derived from the CO2 adsorption data at 0 ºC (VDRCO2. In contrast, CO2 adsorption capacities at 25 ºC and 15 kPa are more related to only pores of sizes lower than 0.7 nm. The capacity values obtained in column adsorption experiments were really promising. An activated carbon fiber obtained from Alcell lignin, FCL, presented a capacity value of 1.3 mmol/g (5.7 %wt. Moreover, the adsorption capacity of this carbon fiber was totally recovered in a very fast desorption cycle at the same operation temperature and total pressure and, therefore, without any additional energy requirement. Thus, these results suggest that the biomass waste used in this work could be successfully valorized as efficient CO2 adsorbent, under post-combustion conditions, showing excellent regeneration performance.

  17. Suppression of the Thermal Decomposition Reaction of Forest Combustible Materials in Large-Area Fires

    Science.gov (United States)

    Volkov, R. S.; Zhdanova, A. O.; Kuznetsov, G. V.; Strizhak, P. A.

    2018-05-01

    Experimental investigations on the characteristic time of suppression of the thermal decomposition reaction of typical forest combustible materials (aspen twigs, birch leaves, spruce needles, pine chips, and a mixture of these materials) and the volume of water required for this purpose have been performed for model fire hotbeds of different areas: SFCM = 0.0003-0.007 m2 and SFCM = 0.045-0.245 m2. In the experiments, aerosol water flows with droplets of size 0.01-0.25 mm were used for the spraying of model fire hotbeds, and the density of spraying was 0.02 L/(m2·s). It was established that the characteristics of suppression of a fire by an aerosol water flow are mainly determined by the sizes of the droplets in this flow. Prognostic estimates of changes in the dispersivity of a droplet cloud, formed from large (as large as 0.5 L) "drops" (water agglomerates) thrown down from a height, have been made. It is shown that these changes can influence the conditions and characteristics of suppression of a forest fire. Dependences, allowing one to forecast the characteristics of suppression of the thermal decomposition of forest combustible materials with the use of large water agglomerates thrown down from an aircraft and aerosol clouds formed from these agglomerates in the process of their movement to the earth, are presented.

  18. Suppression of the Thermal Decomposition Reaction of Forest Combustible Materials in Large-Area Fires

    Science.gov (United States)

    Volkov, R. S.; Zhdanova, A. O.; Kuznetsov, G. V.; Strizhak, P. A.

    2018-03-01

    Experimental investigations on the characteristic time of suppression of the thermal decomposition reaction of typical forest combustible materials (aspen twigs, birch leaves, spruce needles, pine chips, and a mixture of these materials) and the volume of water required for this purpose have been performed for model fire hotbeds of different areas: SFCM = 0.0003-0.007 m2 and SFCM = 0.045-0.245 m2. In the experiments, aerosol water flows with droplets of size 0.01-0.25 mm were used for the spraying of model fire hotbeds, and the density of spraying was 0.02 L/(m2·s). It was established that the characteristics of suppression of a fire by an aerosol water flow are mainly determined by the sizes of the droplets in this flow. Prognostic estimates of changes in the dispersivity of a droplet cloud, formed from large (as large as 0.5 L) "drops" (water agglomerates) thrown down from a height, have been made. It is shown that these changes can influence the conditions and characteristics of suppression of a forest fire. Dependences, allowing one to forecast the characteristics of suppression of the thermal decomposition of forest combustible materials with the use of large water agglomerates thrown down from an aircraft and aerosol clouds formed from these agglomerates in the process of their movement to the earth, are presented.

  19. Physical and combustion characterization of pyrolytic oils derived from biomass material upgraded by catalytic hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Vitolo, S.; Ghetti, P. (Universita di Pisa, Pisa (Italy). Dipartimento di Ingegneria Chimica)

    1994-11-01

    Physical and combustion properties of a pyrolytic bio-oil are determined both as-obtained and after catalytic hydrodeoxygenation. The tests demonstrate that the hydrogenation treatment improves the oil as regards combustibility, viscosity and acidity. Combustion properties of the oil have been characterized by evaporation and temperature programmed combustion profiles. Short communication. 21 refs., 4 figs., 2 tabs.

  20. Aerial radiological survey of the Feed Materials Production Center and surrounding area, Fernald, Ohio. Date of survey: April 1985

    International Nuclear Information System (INIS)

    1985-10-01

    An aerial radiological survey was performed over the area surrounding the Feed Materials Production Center, located near Fernald, Ohio, during the period April 24 to 27, 1985. The survey covered a 70-square-kilometer (27-square-mile) area centered on the plant. The highest exposure rates, in excess of 0.35 milliroentgens per hour (mR/h), were inferred from the data measured directly over the plant. This radiation was due to the presence of nuclides which were consistent with normal plant operations. For the remainder of the survey area, the inferred radiation exposure rates, varying from 6 to 12 microroentgens per hour (μR/h), were due to naturally-occurring potassium, uranium, thorium, and daughter products. The reported exposure rate values include an estimated cosmic ray contribution of 3.7μR/h. Ground-based measurements, conducted during the time of the aerial survey, were compared to the aerial results. Pressurized ionization chamber readings and a group of soil samples were acquired at several locations within the survey area. The exposure rate values obtained from these measurements were in agreement with the inferred aerial results. Soil sample results showed several areas just outside the site boundary with slightly elevated amounts of U-238. The levels, however, were well below the detection limit of the aerial system. The only off-site area that showed apparent above background activity in the aerial data was directly west of the storage silos. The symmetric shape of the contours, however, suggests that these elevated levels are due to ''shine'' from material stored on-site in the silos and not to actual off-site contamination. Detailed comparison of the 1985 aerial survey data with a previous survey conducted in 1976 showed no significant change in any area outside the plant boundary. 6 refs., 9 figs., 3 tabs

  1. Smart Surroundings

    NARCIS (Netherlands)

    Havinga, Paul J.M.; Jansen, P.G.; Lijding, M.E.M.; Scholten, Johan

    2004-01-01

    Ambient systems are networked embedded systems integrated with everyday environments and supporting people in their activities. These systems will create a Smart Surrounding for people to facilitate and enrich daily life and increase productivity at work. Such systems will be quite different from

  2. Fluidised bed combustion system

    International Nuclear Information System (INIS)

    McKenzie, E.C.

    1976-01-01

    Fluidized bed combustion systems that facilitates the maintenance of the depth of the bed are described. A discharge pipe projects upwardly into the bed so that bed material can flow into its upper end and escape downwardly. The end of the pipe is surrounded by an enclosure and air is discharged into the enclosure so that material will enter the pipe from within the enclosure and have been cooled in the enclosure by the air discharged into it. The walls of the enclosure may themselves be cooled

  3. Efficient Flame Detection and Early Warning Sensors on Combustible Materials Using Hierarchical Graphene Oxide/Silicone Coatings.

    Science.gov (United States)

    Wu, Qian; Gong, Li-Xiu; Li, Yang; Cao, Cheng-Fei; Tang, Long-Cheng; Wu, Lianbin; Zhao, Li; Zhang, Guo-Dong; Li, Shi-Neng; Gao, Jiefeng; Li, Yongjin; Mai, Yiu-Wing

    2018-01-23

    Design and development of smart sensors for rapid flame detection in postcombustion and early fire warning in precombustion situations are critically needed to improve the fire safety of combustible materials in many applications. Herein, we describe the fabrication of hierarchical coatings created by assembling a multilayered graphene oxide (GO)/silicone structure onto different combustible substrate materials. The resulting coatings exhibit distinct temperature-responsive electrical resistance change as efficient early warning sensors for detecting abnormal high environmental temperature, thus enabling fire prevention below the ignition temperature of combustible materials. After encountering a flame attack, we demonstrate extremely rapid flame detection response in 2-3 s and excellent flame self-extinguishing retardancy for the multilayered GO/silicone structure that can be synergistically transformed to a multiscale graphene/nanosilica protection layer. The hierarchical coatings developed are promising for fire prevention and protection applications in various critical fire risk and related perilous circumstances.

  4. Gaseous products and smoke generation on combustion of the insulation materials of nuclear cables

    International Nuclear Information System (INIS)

    Noguchi, Isamu; Takami, Hiroshi; Ueyama, Michio; Fujimura, Shun-ichi.

    1976-01-01

    Serious requirements have been introduced to the cables used for nuclear power plants on their flame retardation in the IEEE Standard 383-1974. The movements that the users prescribe the quantity of corrosive gas generated from cables are also observed. This report describes on the measured results of the gaseous products generated by burning polyethylene, polyvinyl-chloride (PVC) and their flame-resistant products, and a part of the covering materials of the cables for nuclear power plants (flame-resistant, crosslinking polyethylene, flame-resistant, low hydrochloric acid PVC, flame-resistant jute) in the infra-red rapid heating combustion test facility designed by the Furukawa Electric Co. Ltd. In addition, the report introduces the test method for the smoke generation evaluation of polymers and a part of the measured results. The gaseous products of combustion were collected and determined quantitatively by gas chromatographic method. Since smoke generation is affected greatly by the kinds, shape, atmosphere, temperature, ignition procedure and others of burnt matters, the establishment of the evaluation test method is difficult, and a number of methods have been proposed. As the measured results showed, it is clear that smoke generation increases with the increase of flame resistant reagent addition. The smoke generation of PVC was of course great in quantity because it contains considerable amount of chlorine for its molecular structure. Flame-resistant polyethylene generates smoke much more than polyethylene without flame-resisting treatment because of its flame resistivity, but less than that of PVC. (Wakatsuki, Y.)

  5. Performance of candidate gas turbine abradeable seal materials in high temperature combustion atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Simms, N.J. [Cranfield University, Power Generation Technology Centre, Cranfield, Beds, MK43 0AL (United Kingdom); Norton, J.F. [Cranfield University, Power Generation Technology Centre, Cranfield, Beds, MK43 0AL (United Kingdom); Consultant in Corrosion Science and Technology, Hemel Hempstead, Herts HP1 1SR (United Kingdom); McColvin, G. [Siemens Industrial Turbines Ltd., Lincoln, LN5 7FD (United Kingdom)

    2005-11-01

    The development of abradeable gas turbine seals for higher temperature duties has been the target of an EU-funded R and D project, ADSEALS, with the aim of moving towards seals that can withstand surface temperatures as high as {proportional_to} 1100 C for periods of at least 24,000 h. The ADSEALS project has investigated the manufacturing and performance of a number of alternative materials for the traditional honeycomb seal design and novel alternative designs. This paper reports results from two series of exposure tests carried out to evaluate the oxidation performance of the seal structures in combustion gases and under thermal cycling conditions. These investigations formed one part of the evaluation of seal materials that has been carried out within the ADSEALS project. The first series of three tests, carried out for screening purposes, exposed candidate abradeable seal materials to a simulated natural gas combustion environment at temperatures within the range 1050-1150 C in controlled atmosphere furnaces for periods of up to {proportional_to} 2,500 h with fifteen thermal cycles. The samples were thermally cycled to room temperature on a weekly basis to enable the progress of the degradation to be monitored by mass change and visual observation, as well as allowing samples to be exchanged at planned intervals. The honeycombs were manufactured from PM2000 and Haynes 214. The backing plates for the seal constructions were manufactured from Haynes 214. Some seals contained fillers or had been surface treated (e.g. aluminised). The second series of three tests were carried out in a natural gas fired ribbon furnace facility that allowed up to sixty samples of candidate seal structures (including honeycombs, hollow sphere structures and porous ceramics manufactured from an extended range of materials including Aluchrom YHf, PM2Hf, Haynes 230, IN738LC and MarM247) to be exposed simultaneously to a stream of hot combustion gas. In this case the samples were cooled

  6. Low-reactive circulating fluidized bed combustion (CFBC) fly ashes as source material for geopolymer synthesis

    International Nuclear Information System (INIS)

    Xu Hui; Li Qin; Shen Lifeng; Zhang Mengqun; Zhai Jianping

    2010-01-01

    In this contribution, low-reactive circulating fluidized bed combustion (CFBC) fly ashes (CFAs) have firstly been utilized as a source material for geopolymer synthesis. An alkali fusion process was employed to promote the dissolution of Si and Al species from the CFAs, and thus to enhance the reactivity of the ashes. A high-reactive metakaolin (MK) was also used to consume the excess alkali needed for the fusion. Reactivities of the CFAs and MK were examined by a series of dissolution tests in sodium hydroxide solutions. Geopolymer samples were prepared by alkali activation of the source materials using a sodium silicate solution as the activator. The synthesized products were characterized by mechanical testing, scanning electron microscopy (SEM), X-ray diffractography (XRD), as well as Fourier transform infrared spectroscopy (FTIR). The results of this study indicate that, via enhancing the reactivity by alkali fusion and balancing the Na/Al ratio by additional aluminosilicate source, low-reactive CFAs could also be recycled as an alternative source material for geopolymer production.

  7. Combustion of peanut shells in a cone-shaped bubbling fluidized-bed combustor using alumina as the bed material

    International Nuclear Information System (INIS)

    Arromdee, Porametr; Kuprianov, Vladimir I.

    2012-01-01

    Highlights: ► We propose burning of peanut shells in a conical fluidized bed using alumina sand. ► We examine hydrodynamic, combustion and emission characteristics of the reactor. ► High, over 99%, combustion efficiency is achievable. ► Emissions of CO and NO from the combustor meet the national emission limits. ► Composition of the bed material undergoes significant changes during the combustion. -- Abstract: This paper reports experimental studies on burning peanut shells in the conical fluidized-bed combustor using alumina sand as the fluidizing agent. Prior to combustion tests, hydrodynamic regimes and characteristics of a conical alumina–biomass bed were investigated under cold-state conditions for variable percentage of peanut shells in the mixture and static bed height. With selected particle sizes (300–500 μm) and static bed height (30 cm), alumina ensured bubbling fluidization regime of the bed at operating conditions specified for firing biomass. Combustion tests were performed at 60 kg/h and 45 kg/h fuel feed rates, while ranging excess air from 20% to 80% at a fixed combustor load. Temperature and gas concentrations (O 2 , CO, C x H y as CH 4 , and NO) were measured along radial and axial directions inside the reactor as well as at stack in order to characterize combustion and emission performance of the combustor for the ranges of operating conditions. For firing 60 kg/h peanut shells, excess air of 40% can be selected as an appropriate value ensuring high, about 99%, combustion efficiency and rather low emissions of CO and NO: 520 ppm and 125 ppm, respectively (both on a dry basis and at 6% O 2 ). With reducing combustor load, the combustion efficiency and emission characteristics were improved to a little extent. No evidence of bed agglomeration was found during 30-h combustion tests on this conical fluidized-bed combustor using alumina sand as the bed material. However, the timescale effect on the composition of the bed material was

  8. Plant growth response in experimental soilless mixes prepared from coal combustion products and organic waste materials

    Energy Technology Data Exchange (ETDEWEB)

    Bardhan, S.; Watson, M.; Dick, W.A. [Ohio State University, Wooster, OH (United States)

    2008-07-15

    Large quantities of organic materials such as animal manures, yard trimmings, and biosolids are produced each year. Beneficial use options for them are often limited, and composting has been proposed as a way to better manage these organic materials. Similarly, burning of coal created 125 million tons of coal combustion products (CCP) in the United States in 2006. An estimated 53 million tons of CCP were reused, whereas the remainder was deposited in landfills. By combining CCP and composted organic materials (COM), we were able to create soilless plant growth mixes with physicochemical conditions that can support excellent plant growth. An additional benefit is the conservation of natural raw materials, such as peat, which is generally used for making soilless mixes. Experimental mixes were formulated by combining CCP and COM at ratios ranging from 2:8 to 8:2 (vol/vol), respectively. Water content at saturation for the created mixes was 63% to 72%, whereas for the commercial control, it was 77%. pH values for the best performing mixes ranged between 5.9 and 6.8. Electrical conductivity and concentrations of required plant nutrient were also within plant growth recommendations for container media. Significantly (P < 0.0001) higher plant biomass growth (7%-130%) was observed in the experimental mixes compared with a commercial mix. No additional fertilizers were provided during the experiment, and reduced fertilization costs can thus accrue as an added benefit to the grower. In summary, combining CCP and COM, derived from source materials often viewed as wastes, can create highly productive plant growth mixes.

  9. Effect of Metal Additives on the Combustion Characteristics of High-Energy Materials

    OpenAIRE

    Korotkikh, Aleksandr Gennadievich; Glotov, Oleg; Sorokin, Ivan

    2016-01-01

    Thermodynamic calculation of combustion parameters and equilibrium composition of HEMs combustion products showed, that at the increase of aluminum powder dispersity the specific impulse and combustion temperature of solid propellants are reduced due to the decrease of the mass fraction of active aluminum in particles. Partial or complete replacement of aluminum by metal powder (B, Mg, AlB[2], Al\\Mg alloy, Fe, Ti and Zr) in HEMs composition leads to the reduce of the specific impulse and comb...

  10. Evaluation of coal combustion byproducts as soil liming materials - their influence on soil pH and enzyme activities

    Energy Technology Data Exchange (ETDEWEB)

    McCarty, G W; Siddaramappa, R; Wright, R J; Codling, E E; Gao, G

    1994-03-01

    To evaluate coal combustion byproducts as liming materials and address issues related to soil quality, the authors compared the influence of different amounts of four combustion byproducts (fly ash and bed ash from a fluidized bed combustion furnace, lime-injected multistage burner residue, and spray dryer residue) and CaCO[sub 3] on soil pH and activities of urease, phosphatase, arylsulfatase, and dehydrogenase in an acidic soil. Studies comparing the influence of the combustion byproducts and CaCO[sub 3] on soil pH showed that on weight basis of application, substantial differences were observed in the ability of these materials to influence soil pH but that such differences decreased markedly after the data were transformed to a CaCO[sub 3] equivalent basis of application. Analysis of covariance for these transformed data indicated that whereas the liming abilities of fly ash and CaCO[sub 3] were not significantly different when compared on the CaCO[sub 3] equivalent basis, those of bed ash, multistage burner residue, and spray dryer residue were less than that of CaCO[sub 3]. Studies comparing the influence of the byproducts and CaCO[sub 3] on soil enzyme activities showed that the effect of these liming materials on the enzyme activities studied was largely due to their influence on soil pH. These studies showed that the combustion byproducts tested functioned as soil liming materials in a manner similar to that of CaCO[sub 3] and seemed to have little adverse effect on soil quality.

  11. Naturally Occurring Radioactive Materials in Uranium-Rich Coals and Associated Coal Combustion Residues from China.

    Science.gov (United States)

    Lauer, Nancy; Vengosh, Avner; Dai, Shifeng

    2017-11-21

    Most coals in China have uranium concentrations up to 3 ppm, yet several coal deposits are known to be enriched in uranium. Naturally occurring radioactive materials (NORM) in these U-rich coals and associated coal combustion residues (CCRs) have not been well characterized. Here we measure NORM (Th, U, 228 Ra, 226 Ra, and 210 Pb) in coals from eight U-rich coal deposits in China and the associated CCRs from one of these deposits. We compared NORM in these U-rich coals and associated CCRs to CCRs collected from the Beijing area and natural loess sediments from northeastern China. We found elevated U concentrations (up to 476 ppm) that correspond to low 232 Th/ 238 U and 228 Ra/ 226 Ra activity ratios (≪1) in the coal samples. 226 Ra and 228 Ra activities correlate with 238 U and 232 Th activities, respectively, and 226 Ra activities correlate well with 210 Pb activities across all coal samples. We used measured NORM activities and ash yields in coals to model the activities of CCRs from all U-rich coals analyzed in this study. The activities of measured and modeled CCRs derived from U-rich coals exceed the standards for radiation in building materials, particularly for CCRs originating from coals with U > 10 ppm. Since beneficial use of high-U Chinese CCRs in building materials is not a suitable option, careful consideration needs to be taken to limit potential air and water contamination upon disposal of U- and Ra-rich CCRs.

  12. Quantitative data on the fire behavior of combustible materials found in nuclear power plants: A literature review

    International Nuclear Information System (INIS)

    Nowlen, S.P.

    1987-02-01

    This report presents the findings of a task in which currently available fire research literature was reviewed for quantitative data on the burning characteristics of combustible materials that are found in nuclear power plants. The materials considered for which quantitative data were available include cable insulation materials, flammable liquids, furniture, trash and general refuse, and wood and wood products. A total of 90 figures and tables, taken primarily from the referenced works, which summarize the available quantitative fire characterization information for these materials is presented

  13. Properties of Controlled Low Strength Material with Circulating Fluidized Bed Combustion Ash and Recycled Aggregates

    Science.gov (United States)

    Weng, Tsai-Lung; Cheng, An; Chao, Sao-Jeng; Hsu, Hui-Mi

    2018-01-01

    This study aims to investigate the effect of adding circulating fluidized bed combustion (CFBC) ash, desulfurization slag, air-cooled blast-furnace slag and coal bottom ash to the controlled low-strength material (CLSM). Test methods include slump flow test, ball drop test, water soluble chloride ion content measurement, compressive strength and length change measurement. The results show that (1) the use of CFBC hydration ash with desulfurization slag of slump flow is the best, and the use of CFBC hydration ash with coal bottom ash and slump flow is the worst; (2) CFBC hydration ash with desulfurization slag and chloride ion content is the highest; (3) 24 h ball drop test (diameter ≤ 76 mm), and test results are 70 mm to 76 mm; (4) CFBC hydration ash with desulfurization slag and compression strength is the highest, with the coal bottom ash being the lowest; increase of CFBC hydration ash can reduce compressive strength; and (5) the water-quenched blast furnace slag and CFBC hydration ash would expand, which results in length changes of CLSM specimens. PMID:29724055

  14. Effect of Metal Additives on the Combustion Characteristics of High-Energy Materials

    Directory of Open Access Journals (Sweden)

    Korotkikh Alexander

    2016-01-01

    Full Text Available Thermodynamic calculation of combustion parameters and equilibrium composition of HEMs combustion products showed, that at the increase of aluminum powder dispersity the specific impulse and combustion temperature of solid propellants are reduced due to the decrease of the mass fraction of active aluminum in particles. Partial or complete replacement of aluminum by metal powder (B, Mg, AlB2, Al\\Mg alloy, Fe, Ti and Zr in HEMs composition leads to the reduce of the specific impulse and combustion temperature. Replacement of aluminum powder by boron and magnesium in HEM reduces the mass fraction of condensed products in the combustion chamber of solid rocket motor. So, for compositions HEMs with boron and aluminum boride the mass fraction in chamber is reduced by 24 and 36 %, respectively, with respect to the composition HEMs with Al powder. But the mass fraction of CCPs in the nozzle exit increases by 13 % for HEMs with aluminum boride due to the formation of boron oxide in the condensed combustion products. Partial replacement of 2 wt. % aluminum powder by iron and copper additives in HEM leads to the reduce of CCPs mass fraction in chamber by 4–10 % depending on the aluminum powder dispersity duo to these metals are not formed condensed products at the HEMs combustion in chamber.

  15. Fabrication and processing of next-generation oxygen carrier materials for chemical looping combustion

    Energy Technology Data Exchange (ETDEWEB)

    Nadarajah, Arunan [Univ. of Toledo, OH (United States)

    2017-04-26

    Among numerous methods of controlling the global warming effect, Chemical Looping Combustion is known to be the most viable option currently. A key factor to a successful chemical looping process is the presence of highly effective oxygen carriers that enable fuel combustion by going through oxidation and reduction in the presence of air and fuel respectively. In this study, CaMnO3-δ was used as the base material and doped on the A-site (Sr or La) and B-site (Fe, Ti, Zn and Al) by 10 mol % of dopants. Solid state reaction followed by mechanical extrusion (optimized paste formula) was used as the preparation method A series of novel doped perovskite-type oxygen carrier particles (CaxLa (Or Sa)1-x Mn1-yByO3-δ (B-site = Fe, Ti, Al, or Zr)) were synthesized by the proposed extrusion formula. The produced samples were characterized with XRD, SEM, BET and TGA techniques. According to the results obtained from TGA analysis, the oxygen capacity of the samples ranged between 1.2 for CLMZ and 1.75 for CSMF. Reactivity and oxygen uncoupling behaviors of the prepared samples were also evaluated using a fluidized bed chemical looping reactor using methane as the fuel at four different temperatures (800, 850, 900, 950 °C). All of the oxygen carriers showed oxygen uncoupling behavior and they were able to capture and release oxygen. Mass-based conversion of the perovskites was calculated and temperature increase proved to increase the mass-based conversion rate in all of the samples under study. Gas yield was calculated at 950 °C as well, and results showed that CLMZ, CM and CSMF showed 100% gas yields and CLMF and CSMZ showed approximately 85% yield in fluidized bed reactor, which is a high and acceptable quantity. Based on extended reactor tests the modified calcium manganese perovskite structures (CSMF) can be a good candidate for future pilot tests.

  16. Corrosion behaviour of boiler tube materials during combustion of fuels containing Zn and Pb

    Energy Technology Data Exchange (ETDEWEB)

    Bankiewicz, D.

    2012-11-01

    Many power plants burning challenging fuels such as waste-derived fuels experience failures of the superheaters and/or increased waterwall corrosion due to aggressive fuel components already at low temperatures. To minimize corrosion problems in waste-fired boilers, the steam temperature is currently kept at a relatively low level which drastically limits power production efficiency. The elements found in deposits of waste and waste-derived fuels burning boilers that are most frequently associated with high-temperature corrosion are: Cl, S, and there are also indications of Br; alkali metals, mainly K and Na, and heavy metals such as Pb and Zn. The low steam pressure and temperature in waste-fired boilers also influence the temperature of the waterwall steel which is nowadays kept in the range of 300 deg C - 400 deg C. Alkali chloride (KCl, NaCl) induced high-temperature corrosion has not been reported to be particularly relevant at such low material temperatures, but the presence of Zn and Pb compounds in the deposits have been found to induce corrosion already in the 300 deg C - 400 deg C temperature range. Upon combustion, Zn and Pb may react with Cl and S to form chlorides and sulphates in the flue gases. These specific heavy metal compounds are of special concern due to the formation of low melting salt mixtures. These low melting, gaseous or solid compounds are entrained in the flue gases and may stick or condense on colder surfaces of furnace walls and superheaters when passing the convective parts of the boiler, thereby forming an aggressive deposit. A deposit rich in heavy metal (Zn, Pb) chlorides and sulphates increases the risk for corrosion which can be additionally enhanced by the presence of a molten phase. The objective of this study was to obtain better insight into high-temperature corrosion induced by Zn and Pb and to estimate the behaviour and resistance of some boiler superheater and waterwall materials in environments rich in those heavy metals

  17. Development of teaching material to integrate GT-POWER into combustion courses for IC engine simulations.

    Science.gov (United States)

    2009-02-01

    The main objective of this project was to develop instructional engineering projects that utilize the newly-offered PACE software GT-POWER for engine simulations in combustion-related courses at the Missouri University of Science and Technology. Stud...

  18. Determination of the hydrogen isotopic compositions of organic materials and hydrous minerals using thermal combustion laser spectroscopy.

    Science.gov (United States)

    Koehler, Geoff; Wassenaar, Leonard I

    2012-04-17

    Hydrogen isotopic compositions of hydrous minerals and organic materials were measured by combustion to water, followed by optical isotopic analysis of the water vapor by off-axis integrated cavity output spectroscopy. Hydrogen and oxygen isotopic compositions were calculated by numerical integration of the individual isotopologue concentrations measured by the optical spectrometer. Rapid oxygen isotope exchange occurs within the combustion reactor between water vapor and molecular oxygen so that only hydrogen isotope compositions may be determined. Over a wide range in sample sizes, precisions were ±3-4 per mil. This is comparable but worse than continuous flow-isotope ratio mass spectroscopy (CF-IRMS) methods owing to memory effects inherent in water vapor transfer. Nevertheless, the simplicity and reduced cost of this analysis compared to classical IRMS or CF-IRMS methods make this an attractive option to determine the hydrogen isotopic composition of organic materials where the utmost precision or small sample sizes are not needed.

  19. Gel-like properties of MCM-41 material and its transformation to MCM-50 in a caustic alkaline surround

    International Nuclear Information System (INIS)

    Saputra, Hens; Othman, Raihan; Sutjipto, A.G.E.; Muhida, R.; Ani, M.H.

    2012-01-01

    Highlights: ► MCM-41 material transforms gradually into MCM-50 lamellar gel upon controlled exposure to 6 M KOH. ► The formation of MCM-50 ordered gel structure occurs at KOH weight content of 40–70 wt. %. ► MCM gel phase shows pseudoplastic behavior and possesses homogeneous matrix texture. -- Abstract: MCM-41 material, prepared by sol–gel method, reveals gel-like properties in a caustic alkaline environment, i.e., 6 M potassium hydroxide (KOH) electrolyte. The gellation of MCM-41 starts at a KOH weight ratio of 40 wt.%. The structural change of the material is verified with X-Ray diffractograms and supported by observation using Scanning Electron Microscope (SEM). As the KOH weight ratio increases, the MCM-41 hexagonal arrays structure gradually transforms into MCM-50 lamellar structure before disappearing completely at 80 wt.% KOH. The MCM gel phase is further characterized by rotational viscometry and texture analysis. The gel phase shows shear thinning or pseudoplastic behavior and possesses homogeneous matrix structure.

  20. Nanocrystals-based Macroporous Materials Synthesized by Freeze-drying Combustion

    International Nuclear Information System (INIS)

    Yan, Ruiqiang; Chen, Yu; Lin, Ye; Chen, Fanglin

    2016-01-01

    We present a novel freeze-drying combustion method for synthesis of macroporous powders with nano-network, using Sm 0.2 Ce 0.8 O 1.9 (SDC) as an example. The metal nitrate salt solution mixed with glycine is frozen to form homogeneous nitrate/glycine mixture and then freeze-dried through sublimation of ice crystals. Upon combustion of the freeze-dried mixture, SDC powders with macroporous microstructure consisting of 10–20 nm nanocrystals, high surface area and excellent sinterability are achieved. High resolution transmission electron microscopy (HRTEM) analysis indicates that nanodomains due to aggregation/segregation of dopants in the SDC powders obtained from freeze-drying combustion are much smaller than those in the SDC powders synthesized by the conventional nitrate solution combustion approach, demonstrating better elemental homogeneity and improved conductivity. Using low cost precursors and simple processing conditions, freeze-drying combustion can be a versatile method to synthesize nanocrystalline powders with excellent composition homogeneity for broad applications.

  1. Screening of candidate corrosion resistant materials for coal combustion environments -- Volume 4. Final report, January 31, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Boss, D.E.

    1997-12-31

    The development of a silicon carbide heat exchanger is a critical step in the development of the Externally-Fired Combined Cycle (EFCC) power system. SiC is the only material that provides the necessary combination of resistance to creep, thermal shock, and oxidation. While the SiC structural materials provide the thermomechanical and thermophysical properties needed for an efficient system, the mechanical properties of the SiC tubes are severely degraded through corrosion by the coal combustion products. To obtain the necessary service life of thousands of hours at temperature, a protective coating is needed that is stable with both the SiC tube and the coal combustion products, resists erosion from the particle laden gas stream, is thermal-shock resistant, adheres to SiC during repeated thermal shocks (start-up, process upsets, shut-down), and allows the EFCC system to be cost competitive. The candidate protective materials identified in a previous effort were screened for their stability to the EFCC combustion environment. Bulk samples of each of the eleven candidate materials were prepared, and exposed to coal slag for 100 hours at 1,370 C under flowing air. After exposure the samples were mounted, polished, and examined via x-ray diffraction, energy dispersive spectroscopy, and scanning electron microscopy. In general, the alumina-based materials behaved well, with comparable corrosion depths in all five samples. Magnesium chromite formed a series of reaction products with the slag, which included an alumina-rich region. These reaction products may act as a diffusion barrier to slow further reaction between the magnesium chromite and the slag and prove to be a protective coating. As for the other materials; calcium titanate failed catastrophically, the CS-50 exhibited extension microstructural and compositional changes, and zirconium titanate, barium zironate, and yttrium chromite all showed evidence of dissolution with the slag.

  2. Material movement of medium surrounding an underground nuclear explosion; Mouvement materiel du milieu environnant une explosion nucleaire souterraine

    Energy Technology Data Exchange (ETDEWEB)

    Guerrini, C; Garnier, J L [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1969-07-01

    The results of measurements of the mechanical effects in the, intermediate zone around underground nuclear explosions in Sahara granite are presented. After a description of the main characteristics of the equipment used, the laws drawn up using experimental results for the acceleration, the velocity, and the material displacement are presented. These laws are compared to those published in other countries for nuclear tests in granite, in tuff and in alluvial deposits. (authors) [French] Les resultats de mesures d'effets mecaniques en zone intermediaire autour d'essais nucleaires souterrains dans le granite du Sahara sont exposes. Apres avoir decrit, dans leurs grandes lignes, les materiels utilises, on presente les lois etablies avec les resultats experimentaux pour l'acceleration, la vitesse et le deplacement materiel. Ces lois sont comparees a celles publiees a l'etranger pour des essais nucleaires dans le granite, le tuf et les alluvions. (auteur)

  3. Fire Safety Aspects of Polymeric Materials. Volume 3. Smoke and Toxicity (Combustion Toxicology of Polymers)

    Science.gov (United States)

    1978-01-01

    complete combustion of these polymers and thus minimize cyanide formation (Ball and Boettner, 1973; Junod , 1976). This one example shows the critical...34Visibility Through Fire Smoke," II. Report of Fire Research Institute of Japan. No. 33. pp. 31-49, 1971. T. L. Junod , "Gaseous Emissions and Toxic Hazard

  4. Reconstruction of industrial boiler type DKVR-13 aiming for combustion of waste materials from oil-yielding production

    International Nuclear Information System (INIS)

    Gadzhanov, P.

    1997-01-01

    One of the methods for improving of the energy efficiency is the use of a secondary energy resources such as waste products from industrial processes. In case of the oil extraction a great amount of waste product (sunflower shells) with a good thermal potential is available. During the industrial process from 100 kg raw material 15 kg shells are obtained. The combustion heat is about 1700 kJ/kg. The volatile compounds yield is 66.1%. An installation has been constructed intended to use the waste product from the extraction, consisting of: a water tube boiler with a steam capacity of 20 t/h and two PKM-12 type flue boilers and two DKVR 10-13 type water tube boilers. The DKVR 10-13 type boilers are designed for the production of 22.77 kg/s saturated steam with pressure 1.28 MPa and temperature 194 o C. They have an unified constructional schemes with a two-drum evaporating system and a natural circulation. The furnace has a horizontally evaporation beam washed by the gas flux. The reconstruction is aimed to create condition for the use of the sunflower shells as a main fuel and the natural gas or other fuel as additional. The scheme is one using the sloping bed combustion. 70% of the steam production is due to the shells combustion. Calculations for the grid parameters have been done. An additional heater improves the efficiency with 4.5% and the expected annual fuel saving is 300 t. The introduction of hot air (165 o C) provides both combustion and ecological benefits

  5. Materiais cerâmicos para células a combustível Ceramic materials for fuel cells

    Directory of Open Access Journals (Sweden)

    D. Z. de Florio

    2004-12-01

    Full Text Available A partir da definição de células a combustível, é feita uma introdução sucinta dos tipos de células e dos materiais cerâmicos que são empregados em projeto e fabricação destes dispositivos geradores de energia elétrica. Tomando por base a ampla literatura científica disponível em publicações periódicas internacionais indexadas e arbitradas, bem como patentes, são relatados com detalhes os materiais cerâmicos com comportamento elétrico adequado para uso como eletrólitos, anodos, catodos, interconectores e selantes, que são os componentes básicos de células a combustível de óxidos sólidos. Por fim, é feita uma avaliação do estado da arte na pesquisa e desenvolvimento de materiais cerâmicos para uso em células a combustível de óxidos sólidos.Basic definitions of fuel cells and a brief introduction of different types of fuel cells are given. A review of the most important ceramic materials being considered for the design and fabrication of devices for producing electrical energy is presented. Ceramic materials with suitable electrical behavior to be used as electrolytes, anodes, cathodes, interconnectors, and sealants of solid oxide fuel cells are reported with details, taking into account the large number of available indexed and refereed scientific publications and patents. Finally, an evaluation of the state of the art of the research and development of ceramic materials for solid oxide fuel cells is presented.

  6. A new classification system for biomass and waste materials for their use in combustion

    OpenAIRE

    Jenkinson, Philip

    2016-01-01

    The use of biomass derived solid fuels for electricity generation in combustion, gasification and pyrolysis plant has received increasing levels of interest for commercial operation in recent years. However, there are limited tools available which allow a prediction of the performance of these fuels during thermochemical transformation given an understanding of their original chemical structure. As such, this investigation has concentrated on the derivation of a simply utilised classificat...

  7. The use of halogen carriers and buffers in the spectrographic determination of boron in carbonaceous materials and their combustion products

    International Nuclear Information System (INIS)

    Rucandio, M.I.; Martin, M.; Roca, M.

    1992-01-01

    For the determination of boron in carbonaceous materials (high purity graphite, coals and their processed products, such as ashes and slags from thermoelectric power plants) by atomic emission spectroscopy with direct current arc excitation and photographic recording, the behaviour of the analyte in the presence of halide compounds or spectrochemical buffers has been studied. Among the halides, cupric fluoride at a low concentration (2%) becomes very suitable for the graphite analysis, and at a higher concentration (25%) for coals being necessary in this case to carry out a dilution of samples with graphite. Strontium carbonate as a spectrochemical buffer allows to analyse satisfactorily coals and their combustion products. (author)

  8. The use of halogen carriers and buffers in the spectrographic determination of boron in carbonaceous materials and their combustion products

    International Nuclear Information System (INIS)

    Rucandio, M. I.; Martin, M.; Roca, M.

    1992-01-01

    For the determination of boron in carbonaceous materials (high purity graphite, coals and their processed products, such as ashes and slags from thermoelectric power plants) by atomic emission spectroscopy with direct current are excitation and photographic recording, the behaviour of the analyte in the presence of halide compounds or spectrochemical buffers has been studied. Among the halides, cupric fluoride at a low concentration (2%) becomes very suitable for the graphite analysis, and at a higher concentration (25 %) for coals, being necessary in this case to carry out a dilution of samples with graphite. Strontium carbonate as a spectrochemical buffer allows to analyse satisfactorily coals and their combustion products. (Author) 13 refs

  9. Research Combustion Laboratory (RCL)

    Data.gov (United States)

    Federal Laboratory Consortium — The Research Combustion Laboratory (RCL) develops aerospace propulsion technology by performing tests on propulsion components and materials. Altitudes up to 137,000...

  10. Experimental evaluation of washing for treatment of combustible plutonium-contaminated materials

    International Nuclear Information System (INIS)

    Wilkins, J.D.; Wisbey, S.J.

    1983-03-01

    Laboratory scale experiments have been carried out in order to assess the potential of washing as a method for removing plutonium from contaminated combustible wastes. A wide range of aqueous (eg 1 M HNO 3 , 1 M NaOH) and organic (1,1,2-trichlorotrifluoroethane) reagents have been investigated. Both synthetically contaminated and real wastes have been investigated. The preferred wash reagent has been identified as 1 M sodium hydroxide solution; plutonium recoveries of ca.80 to 90% can be achieved. (author)

  11. Fractionated-combustion analysis of carbonate-containing phases in composite materials of the hydroxyapatite-calcium carbonate system

    Science.gov (United States)

    Goldberg, M. A.; Shibaeva, T. V.; Smirnov, V. V.; Kutsev, S. V.; Barinov, S. M.; Grigorovich, K. V.

    2012-12-01

    Materials in the hydroxyapatite (HA)-calcium carbonate (CC) system were synthesized by a precipitation method from aqueous solutions. According to the data of X-ray phase analysis and IR spectroscopy, the powders consisted of CC and AB-type carbonate-substituted HA (CHA). In order to determine the content of carbonate-containing phases in materials, the temperature-temporal mode of fractionated-combustion analysis of carbon was developed. The quantitative phase ratios and the degree of substitution of carbonate groups in CHA were determined. It was shown that the degree of substitution of carbonate groups in CHA increased from 2.47 to 5.31 wt % as the CC content increased from 13.50 to 88.33 wt %.

  12. Study of new technique of solid combustible materials to determination of volatile elements by flame atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Campos, R.C. de.

    1988-01-01

    A new technique for direct trace element analysis of solid combustible materials is described. The samples (up to 10 mg) are weighed on a graphite platform wich is then placed in a quartz tube, at the focal point of three infrared lamps. When the lamps are turned on, the sample burns in a stream of air, and the resulting dry aerosol containing volatile elements such as Hg, Cd, Bi, Tl, Zn, Pb and Cu is carried into the mixing chamber and thence into the flame, where the atomic absorption measurement is carried out. This technique overcomes chemical sample preparation steps, avoiding contaminations of losses associated with these steps. A ''furnace in flame'' system where the aerosol is transported to a flame heated T-tube is also described. The influence of flame stoichiometry, observation height, platform material and air flux intensity was studied inorder to determine optimal analytical conditions. (author) [pt

  13. Study of materials used for the thermal protection of the intake system for internal combustion engines

    Science.gov (United States)

    Birtok-Băneasă, C.; Raţiu, S.; Puţan, V.; Josan, A.

    2018-01-01

    The present paper focuses on calculation of thermal conductivity for a new materials developed by the authors, using the heat flux plate method. This experimental method consists in placing the sample of the new material in a calorimetric chamber and heating from underside. As the heat flux which passes through the sample material is constant and knowing the values of the temperatures for the both sides of sample, the sample material thermal conductivity is determined. Six types of different materials were tested. Based on the experimental data, the values of the thermal conductivity according to the material and the average temperature were calculated and plotted.

  14. Evaluation of arklone for the decontamination of non-combustible plutonium contaminated materials

    International Nuclear Information System (INIS)

    Gaudie, S.C.; Wilkins, J.D.; Turner, A.D.

    1986-04-01

    The use of Arklone (1,1,2 trichloro-, 1,2,2 trifluoroethane) as a decontamination reagent for plutonium contaminated non-combustible wastes has been investigated on a laboratory scale. Arklone has been found to be effective for the removal of loose Pu0 2 contamination - in particular from organic surfaces - from both synthetic and genuine waste. Of the range of contacting techniques investigated, ultrasonics was the best, though vibrocleaning and low pressure spraying performed well. For painted mild steel, paint stripping followed by treatment with Marshall's solution (an aqueous solution of oxalic acid and hydrogen peroxide) cleaned the surface to below 10 -4 μCi/cm 2 . Alternatively , electrochemical techniques could be used - particularly electrodissolution in nitric acid for stainless steel - to reduce contamination levels to 10 -5 μCi/cm 2 . (author)

  15. Lightweight combustion residues-based structural materials for use in mines. Quarterly report, 1 December 1994--28 February 1995

    Energy Technology Data Exchange (ETDEWEB)

    Chugh, Yoginder P.; Zhang, Yuzhuo; Ghosh, A.K.; Palmer, S.R; Peng, Suping, Xiao, Y. [Southern Illinois Univ., Carbondale, IL (United States)

    1995-12-31

    The overall goal of this project is to develop, design and test artificial supports (post and crib members) for use in mines manufactured from coal combustion by-product (CCB) based lightweight structural materials. The lightweight cement-fly ash grout with density ranging from 70 to 110 pcf has been developed incorporating very high volume (50--60 % of whole solid materials) fly ash. Characterization of individual component materials for the CCB-based structural materials has been performed for Class F fly ash, ASTM Type I cement, lime, silica fume, polypropylene fibers, protein-based foam, water-reducing agents, and calcium chloride. During the past quarter, we emphasized on screening mix designs and establishing mixing and curing procedures. We have demonstrated for the first time that cellular cement-fly ash grout can be developed with very low water: cement ratio (0.32--0.45). After forming, all the samples in the molds were moist cured in a chamber for 24-hours, at 90% relatively humidity (RH) and at 72{degrees}F. They were then demolded and transferred to a low pressure steam chamber (150{degrees}F and 100% RH). After steaming for 24 hours the samples were removed to a moist cure chamber prior to testing.

  16. Effect of raw material particle-size distribution on combustion characteristics of stem wood pellets; Paaverkan av partikelfraktionsfoerdelningen paa utbraenningshastigheten hos traepellets vid nyttjande av olika soenderdelningsmetoder

    Energy Technology Data Exchange (ETDEWEB)

    Israelsson, Samuel; Henriksson, Gunnar; Boman, Christoffer; Oehman, Marcus

    2007-01-15

    The objective of the project was to determine the effect of raw material particle-size distribution on combustion characteristics of stem wood pellets. Several well defined pellet qualities were produced from raw materials (stem wood of pine and spruce) which had both different particle-size distributions and were produced with different milling equipments (hammer mill/refiner). The pellets were produced in a traditional (bench-scale) pellet mill and in a laboratory pellet mill/press. The combustion characteristics of the individual pellets were determined in a laboratory scale oven. Char yield, -shrinkage, -density and the micro pore volume of the produced char were also determined. Differences in total conversion times of approximately 5 % at experimental condition relevant for typical pellets equipment were determined for the different pellet qualities. The underlying reasons for the obtained differences in the combustion characteristics between the different pellet qualities are discussed in the report

  17. Combustible structural composites and methods of forming combustible structural composites

    Science.gov (United States)

    Daniels, Michael A.; Heaps, Ronald J.; Steffler, Eric D.; Swank, W. David

    2013-04-02

    Combustible structural composites and methods of forming same are disclosed. In an embodiment, a combustible structural composite includes combustible material comprising a fuel metal and a metal oxide. The fuel metal is present in the combustible material at a weight ratio from 1:9 to 1:1 of the fuel metal to the metal oxide. The fuel metal and the metal oxide are capable of exothermically reacting upon application of energy at or above a threshold value to support self-sustaining combustion of the combustible material within the combustible structural composite. Structural-reinforcing fibers are present in the composite at a weight ratio from 1:20 to 10:1 of the structural-reinforcing fibers to the combustible material. Other embodiments and aspects are disclosed.

  18. ASSESSMENTS OF FUTURE ENVIRONMENTAL TRENDS AND PROBLEMS OF INCREASED USE, RECYCLING, AND COMBUSTION OF FIBER-REINFORCED, PLASTIC AND METAL COMPOSITE MATERIALS

    Science.gov (United States)

    The purpose of the study is to identify and define future environmental concerns related to the projected utilization, recycling, and combustion of composite materials. The study is being conducted for the Office of Strategic Assessment and Special Studies (OSASS) of the U.S. Env...

  19. The Impact of Coal Combustion Fly Ash Used as a Supplemental Cementitious Material on the Leaching of Constituents from Cements and Concretes

    Science.gov (United States)

    The objective of this report is to compare the leaching of portland cement-based materials that have been prepared with and without coal combustion fly ash to illustrate whether there is evidence that the use of fly ash in cement and concrete products may result in increased leac...

  20. Skylab experiments. Volume 3: Materials science. [Skylab experiments on metallurgy, crystal growth, semiconductors, and combustion physics in weightless environment for high school level education

    Science.gov (United States)

    1973-01-01

    The materials science and technology investigation conducted on the Skylab vehicle are discussed. The thirteen experiments that support these investigations have been planned to evaluate the effect of a weightless environment on melting and resolidification of a variety of metals and semiconductor crystals, and on combustion of solid flammable materials. A glossary of terms which define the space activities and a bibliography of related data are presented.

  1. Process and Material Design for Micro-Encapsulated Ionic Liquids in Post-Combustion CO2 Capture

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Bo [Univ. of Notre Dame, IN (United States); Brennecke, Joan F [Univ. of Notre Dame, IN (United States); McCready, Mark [Univ. of Notre Dame, IN (United States); Stadtherr, Mark [Univ. of Notre Dame, IN (United States)

    2016-11-18

    Aprotic Heterocyclic Anion (AHA) Ionic Liquids (ILs) have been identified as promising new solvents for post-combustion carbon capture due to their high CO2 uptake and the high tenability 1,2 of their binding energy with CO2. Some of these compounds change phase (solid to liquid) on absorption of CO2; these Phase Change ILs (PCILs)3 offer the additional advantage that part of the heat needed to desorb the CO2 from the absorbent is provided by the heat of fusion as the PCIL solidifies upon release of CO2. However, the relatively high viscosity of AHA ILs and the occurrence of a phase change in PCILs present challenges for conventional absorption equipment. To overcome these challenges we are pursuing the use of new technology to micro-encapsulate the AHA ILs and PCILs. Our partners at Lawrence Livermore National Laboratory have successfully demonstrated this technology in the application of post-combustion carbon capture with sodium and potassium carbonate solutions,4 and have recently shown the feasibility of micro-encapsulation of an AHA IL for carbon capture.5 The large effective surface area and high CO2 permeability of the micro-capsules is expected to offset the drawback of the high IL viscosity and to provide for a more efficient and cost-effective mass transfer operation involving AHA ILs and PCILs. These opportunities, however, present us with both process and materials design questions. For example, what is the target CO2 absorption strength (enthalpy of chemical absorption) for the tunable AHA IL? What is the target for micro-capsule diameter in order to obtain a high mass transfer rate and good fluidization performance? What are the appropriate temperatures and pressures for the absorber and stripper? In order to address these and other questions, we have developed a rate-based model of a post-combustion CO2 capture process using micro-encapsulated ILs. As a performance baseline

  2. A novel solution combustion synthesis of cobalt oxide nanoparticles as negative-electrode materials for lithium ion batteries

    International Nuclear Information System (INIS)

    Wen Wei; Wu Jinming; Tu Jiangping

    2012-01-01

    Highlights: ► We examine the electrochemical performance of cobalt oxides fabricated by solution combustion synthesis for rechargeable lithium-ion battery applications. ► The additive of NaF in precursor results in an eruption combustion mode. ► The eruption combustion leads to fluffy networks with smaller grains and more macroporous voids. ► The network contributes to higher discharge capacity, higher initial coulombic efficiency, and better cycling performance for rechargeable lithium-ion batteries. - Abstract: Low cost mass production of cobalt oxide nanoparticles with high electrochemical performance is of practical interest for rechargeable lithium-ion batteries. In this report, cobalt oxide nanoparticles were fabricated by solution combustion synthesis, with the introduction of NaF into the precursor to alter the combustion mode. The novel eruption combustion resulted in fluffy networks with smaller particles and more macroporous voids, which contributed to the higher discharge capacity, higher initial coulombic efficiency, and better cycling performance when compared with that achieved by the conventional combustion mode.

  3. Advanced Materials and Manufacturing for Low-Cost, High-Performance Liquid Rocket Combustion Chambers, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Silicided niobium alloy (C103) combustion chambers have been used extensively in both NASA and DoD liquid rocket propulsion systems. Niobium alloys offer a good...

  4. MnO/N–C anode materials for lithium-ion batteries prepared by cotton-templated combustion synthesis

    Directory of Open Access Journals (Sweden)

    Cheng-Gong Han

    2017-10-01

    Full Text Available We herein report a facile one-pot synthesis of MnO/N-doped carbon (N–C composites via a sustainable cotton-template glycine–nitrate combustion synthesis to yield superior anode materials for Li ion batteries. MnO nanoparticles with several nanometers were well-embedded in a porous N-doped carbon matrix. It displays the unique characteristics, including the shortened Li+-ion transport path, increased contact areas with the electrolyte solution, inhibited volume changes and agglomeration of nanoparticles, as well as good conductivity and structural stability during the cycling process, thereby benefiting the superior cycling performance and rate capability. This favorable electrochemical performance of obtained MnO/N–C composites via a one-pot biomass-templated glycine/nitrate combustion synthesis renders the suitability as anode materials for Li-ion batteries. Keywords: Biomass, Cotton, Manganese oxide, Lithium ion battery, Porous carbon

  5. Method for storing radioactive combustible waste

    Science.gov (United States)

    Godbee, H.W.; Lovelace, R.C.

    1973-10-01

    A method is described for preventing pressure buildup in sealed containers which contain radioactively contaminated combustible waste material by adding an oxide getter material to the container so as to chemically bind sorbed water and combustion product gases. (Official Gazette)

  6. The emissions of VOCs during co-combustion of coal with different waste materials in a fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    I. Gulyurtlu; P. Abelha; A. Gregorio; A. Garcia-Garcia; D. Boavida; A. Crujeira; I. Cabrita [DEECA-INETI, Lisbon (Portugal)

    2004-06-01

    The combustion of different fuels gives rise to the formation of small but appreciable amounts of volatile organic compounds (VOCs). They basically result from incomplete combustion and their emissions have negative repercussions on health and on the environment in general. As their measurement is difficult, costly, and very time-consuming, very little is reported on the emissions of VOCs from combustion installations. In this study, various blends of two different coals with several wastes were burned in a pilot-scale fluidized bed combustor and measurements of VOCs at several locations along the combustor height as well as just before the stack were carried out. The results demonstrate that the parameters important for the formation of VOCs are temperature, excess air levels, and the effectiveness of the mixing of air with fuel. Furthermore, it was observed that coal was the principal source of VOCs, but the combustion of volatiles from fuels such as biomass, occurring in the freeboard, was important in reducing the emissions of VOCs to almost zero. 8 refs., 6 figs., 6 tabs.

  7. Thermal and mechanical behaviour of oxygen carrier materials for chemical looping combustion in a packed bed reactor

    NARCIS (Netherlands)

    Jacobs, M.; Van Noyen, J.; Larring, Y.; McCann, M.; Pishahang, M.; Amini, S.; Ortiz, M.; Galluci, F.; Sint-Annaland, M. V.; Tournigant, D.; Louradour, E.; Snijkers, F.

    2015-01-01

    Chemical looping combustion (CLC) is a promising carbon capture technology where cyclic reduction and oxidation of a metallic oxide, which acts as a solid oxygen carrier, takes place. With this system, direct contact between air and fuel can be avoided, and so, a concentrated CO2 stream is generated

  8. Toxicological and chemical characterization of the process stream materials and gas combustion products of an experimental low-btu coal gasifier.

    Science.gov (United States)

    Benson, J M; Hanson, R L; Royer, R E; Clark, C R; Henderson, R F

    1984-04-01

    The process gas stream of an experimental pressurized McDowell-Wellman stirred-bed low-Btu coal gasifier, and combustion products of the clean gas were characterized as to their mutagenic properties and chemical composition. Samples of aerosol droplets condensed from the gas were obtained at selected positions along the process stream using a condenser train. Mutagenicity was assessed using the Ames Salmonella mammalian microsome mutagenicity assay (TA98, with and without rat liver S9). All materials required metabolic activation to be mutagenic. Droplets condensed from gas had a specific mutagenicity of 6.7 revertants/microgram (50,000 revertants/liter of raw gas). Methylnaphthalene, phenanthrene, chrysene, and nitrogen-containing compounds were positively identified in a highly mutagenic fraction of raw gas condensate. While gas cleanup by the humidifier-tar trap system and Venturi scrubber led to only a small reduction in specific mutagenicity of the cooled process stream material (4.1 revertants/microgram), a significant overall reduction in mutagenicity was achieved (to 2200 revertants/liter) due to a substantial reduction in the concentration of material in the gas. By the end of gas cleanup, gas condensates had no detectable mutagenic activity. Condensates of combustion product gas, which contained several polycyclic aromatic compounds, had a specific mutagenicity of 1.1 revertants/microgram (4.0 revertants/liter). Results indicate that the process stream material is potentially toxic and that care should be taken to limit exposure of workers to the condensed tars during gasifier maintenance and repair and to the aerosolized tars emitted in fugitive emissions. Health risks to the general population resulting from exposure to gas combustion products are expected to be minimal.

  9. Process for the manufacture of a filter material for cleaning industrial or internal combustion engine exhaust gases and filter material manufactured according to the process. Verfahren zur Herstellung eines Filterstoffes zur Reinigung von industriellen oder Brennkraftmaschinen-Abgasen und ein hiernach hergestellter Filterstoff

    Energy Technology Data Exchange (ETDEWEB)

    Bumbalek, A.

    1986-01-02

    This is a process for the manufacture of a filter material for cleaning industrial or internal combustion engine exhaust gases and filter material manufactured according to the process. The filter material is manufactured from the mineralized combustion product of peel of tropical fruits burnt at a temperature of 820/sup 0/C to 840/sup 0/C in an oxidising atmosphere excluding the production of carbon, particularly using banana skins and orange peels, which product is granulated with carrier materials or compressed.

  10. Characterization of Spatial Impact of Particles Emitted from a Cement Material Production Facility on Outdoor Particle Deposition in the Surrounding Community.

    Science.gov (United States)

    Yu, Chang Ho; Fan, Zhihua Tina; McCandlish, Elizabeth; Stern, Alan H; Lioy, Paul J

    2011-10-01

    The objective of this study was to estimate the contribution of a facility that processes steel production slag into raw material for cement production to local outdoor particle deposition in Camden, NJ. A dry deposition sampler that can house four 37-mm quartz fiber filters was developed and used for the collection of atmospheric particle deposits. Two rounds of particle collection (3-4 weeks each) were conducted in 8-11 locations 200-800 m downwind of the facility. Background samples were concurrently collected in a remote area located ∼2 km upwind from the facility. In addition, duplicate surface wipe samples were collected side-by-side from each of the 13 locations within the same sampling area during the first deposition sampling period. One composite source material sample was also collected from a pile stored in the facility. Both the bulk of the source material and the particle deposition flux in the study area was higher (24-83 mg/m 2 ·day) than at the background sites (13-17 mg/m 2 ·day). The concentration of Ca, a major element in the cement source production material, was found to exponentially decrease with increasing downwind distance from the facility (P particle deposition. The contribution of the facility to outdoor deposited particle mass was further estimated by three independent models using the measurements obtained from this study. The estimated contributions to particle deposition in the study area were 1.8-7.4% from the regression analysis of the Ca concentration in particle deposition samples against the distance from the facility, 0-11% from the U.S. Environmental Protection Agency (EPA) Chemical Mass Balance (CMB) source-receptor model, and 7.6-13% from the EPA Industrial Source Complex Short Term (ISCST3) dispersion model using the particle-size-adjusted permit-based emissions estimates. [Box: see text].

  11. Oxygen Carrier Aided Combustion (OCAC of Wood Chips in a Semi-Commercial Circulating Fluidized Bed Boiler Using Manganese Ore as Bed Material

    Directory of Open Access Journals (Sweden)

    Magnus Rydén

    2016-11-01

    Full Text Available Oxygen Carrier Aided Combustion (OCAC is realized by using an active oxygen-carrying bed material in fluidized bed boilers. The active material is reduced in fuel rich parts of the boiler and oxidized in air rich parts. Advantages could be achieved such as new mechanisms for oxygen transport in space and time. Here calcined manganese ore has been used as active bed material in a 12 MWth circulating fluidized bed boiler. The fuel was wood chips and the campaign lasted more than two weeks. From an operational point of view, manganese ore worked excellently. From the temperature profile of the boiler it can be concluded that fuel conversion was facilitated, especially in the dense bottom bed. The effect did not always translate to reduced emissions, which suggests that final combustion in the cyclone outlet was also influenced. Substituting 10% of the sand bed with manganese ore made it possible to reduce the air to fuel ratio without generating large amounts of CO. The use of 100% manganese ore resulted in higher emissions of CO than the sand reference, but, when combined sulphur feeding, dramatic reductions in CO emissions, up to 90% compared to sand reference, was achieved.

  12. Combustion engineering

    CERN Document Server

    Ragland, Kenneth W

    2011-01-01

    Introduction to Combustion Engineering The Nature of Combustion Combustion Emissions Global Climate Change Sustainability World Energy Production Structure of the Book   Section I: Basic Concepts Fuels Gaseous Fuels Liquid Fuels Solid Fuels Problems Thermodynamics of Combustion Review of First Law Concepts Properties of Mixtures Combustion StoichiometryChemical EnergyChemical EquilibriumAdiabatic Flame TemperatureChemical Kinetics of CombustionElementary ReactionsChain ReactionsGlobal ReactionsNitric Oxide KineticsReactions at a Solid SurfaceProblemsReferences  Section II: Combustion of Gaseous and Vaporized FuelsFlamesLaminar Premixed FlamesLaminar Flame TheoryTurbulent Premixed FlamesExplosion LimitsDiffusion FlamesGas-Fired Furnaces and BoilersEnergy Balance and EfficiencyFuel SubstitutionResidential Gas BurnersIndustrial Gas BurnersUtility Gas BurnersLow Swirl Gas BurnersPremixed-Charge Engine CombustionIntroduction to the Spark Ignition EngineEngine EfficiencyOne-Zone Model of Combustion in a Piston-...

  13. Comprehensive characterization of humic-like substances in smoke PM2.5 emitted from the combustion of biomass materials and fossil fuels

    Science.gov (United States)

    Fan, Xingjun; Wei, Siye; Zhu, Mengbo; Song, Jianzhong; Peng, Ping'an

    2016-10-01

    Humic-like substances (HULIS) in smoke fine particulate matter (PM2.5) emitted from the combustion of biomass materials (rice straw, corn straw, and pine branch) and fossil fuels (lignite coal and diesel fuel) were comprehensively studied in this work. The HULIS fractions were first isolated with a one-step solid-phase extraction method, and were then investigated with a series of analytical techniques: elemental analysis, total organic carbon analysis, UV-vis (ultraviolet-visible) spectroscopy, excitation-emission matrix (EEM) fluorescence spectroscopy, Fourier transform infrared spectroscopy, and 1H-nuclear magnetic resonance spectroscopy. The results show that HULIS account for 11.2-23.4 and 5.3 % of PM2.5 emitted from biomass burning (BB) and coal combustion, respectively. In addition, contributions of HULIS-C to total carbon and water-soluble carbon in smoke PM2.5 emitted from BB are 8.0-21.7 and 56.9-66.1 %, respectively. The corresponding contributions in smoke PM2.5 from coal combustion are 5.2 and 45.5 %, respectively. These results suggest that BB and coal combustion are both important sources of HULIS in atmospheric aerosols. However, HULIS in diesel soot only accounted for ˜ 0.8 % of the soot particles, suggesting that vehicular exhaust may not be a significant primary source of HULIS. Primary HULIS and atmospheric HULIS display many similar chemical characteristics, as indicated by the instrumental analytical characterization, while some distinct features were also apparent. A high spectral absorbance in the UV-vis spectra, a distinct band at λex/λem ≈ 280/350 nm in EEM spectra, lower H / C and O / C molar ratios, and a high content of [Ar-H] were observed for primary HULIS. These results suggest that primary HULIS contain more aromatic structures, and have a lower content of aliphatic and oxygen-containing groups than atmospheric HULIS. Among the four primary sources of HULIS, HULIS from BB had the highest O / C molar ratios (0.43-0.54) and [H

  14. Study of material stability surrounding with loess-clay-loam rocks on an example of 'Olviya' monument of Ukrainian Northern Prichernomor'ya

    International Nuclear Information System (INIS)

    Zlobenko, B.; Kadoshnikov, V.; Manichev, V.; Demchenko, L.; Golovko, T.; Krapivina, V.

    2000-01-01

    In this work we have examined the archaeological material exhumed from the archaeology monument Olviya. The ancient State Olviya is situated on the territory of Ukraine (Nikolaev region) and it is considered to be an integral part of the world historical legacy. The samples of glasses were collected from P-25 excavation. The collected glasses and metals dated by I-II centuries of our era. They are situated in the south-east part of the Upper State on the territory of the Rome times. Study with the facilitation of physical-chemical and physical methods of research of chemical structure and surface layers of materials. The various physical methods of samples investigation were the following: investigation with half-quantitative spectral analysis performed on spectrograph (CTE-1); X-ray powder diffraction with DRON-UM-1 diffractometers use, X-ray fluorescent analysis (spectrometer VPA-30) and the x-ray microanalysis (JXA-5). Carried out microscopic researches have revealed the specific forms of metals and glasses; corrosion and dissolution of the surface that character is determined by structure and physic-chemical conditions of its burial place. (authors)

  15. Design of lightweight insulation packages for sports cars, component design, material selection and adoption of surrounding properties during the development of the new porsche Carrera Coupe

    Energy Technology Data Exchange (ETDEWEB)

    Lange, C. [Porsche (F.) AG, Weissach (Germany)

    2005-07-01

    Creating a proper insulation package for sports cars means to take into account not only an effective reduction of noise, but also weight optimisation, most possible reduction of package volume and to apply a suitable filter function to create sound. The Carrera's predecessor is a class leading vehicle concerning the weight of the damping and insulation package. Is it possible to improve its performance and shift targets positively? Is it time to exchange existing isolation components by absorption systems? The task for the new development was to style a lightweight trim package which offers a weight and a cost reduction at the same time. The layout considers the special requirements of a high performance sports car and combines the demand for long term rides with a very sporty response behaviour when driving at physical limits. The decision process of material selection is also strongly influenced by realised and expected changes in the design of the power train, chassis, body structure and interior trim components. The question arises if it is possible to regard all the changing noise components in the interior noise sound layout and wait for a final validation of the insulation and trim package until the very end of the development period. (orig.)

  16. Aerial radiological survey of the area surrounding the Feed Materials Production Center, Fernald, Ohio. Dates of surveys, August 1976/May-June 1977

    International Nuclear Information System (INIS)

    Feimster, E.L.

    1979-06-01

    Two aerial radiological surveys to measure terrestrial gamma radiation were made over an area centered on the United States Department of Energy's Feed Materials Production Center in the city of Fernald, Ohio. The Center is operated by the National Lead Company of Ohio. Gamma ray data were collected from east-west flight lines at 90 m intervals over an area 25 km 2 centered on the plant site. The small Ohio towns of Shandon, Ross, and New Baltimore were surveyed from north-south flight lines at 300 m intervals. Processed data indicated that on-site radioactivity was due primarily to radionuclides currently being handled or processed at the Center. Off-site data showed the radioactivity to be due to naturally occurring radionuclides northeast and south of the site. If the northwest corner of the survey area an unusually high count rate region of airborne radon daughter activity was encountered. This was equivalent to approximately four times the normal background. However, the follow-up survey of 1977 showed this area to be within the background count rate level

  17. Direct Energy Supply to the Reaction Mixture during Microwave-Assisted Hydrothermal and Combustion Synthesis of Inorganic Materials

    Directory of Open Access Journals (Sweden)

    Roberto Rosa

    2014-05-01

    Full Text Available The use of microwaves to perform inorganic synthesis allows the direct transfer of electromagnetic energy inside the reaction mixture, independently of the temperature manifested therein. The conversion of microwave (MW radiation into heat is useful in overcoming the activation energy barriers associated with chemical transformations, but the use of microwaves can be further extended to higher temperatures, thus creating unusual high-energy environments. In devising synthetic methodologies to engineered nanomaterials, hydrothermal synthesis and solution combustion synthesis can be used as reference systems to illustrate effects related to microwave irradiation. In the first case, energy is transferred to the entire reaction volume, causing a homogeneous temperature rise within a closed vessel in a few minutes, hence assuring uniform crystal growth at the nanometer scale. In the second case, strong exothermic combustion syntheses can benefit from the application of microwaves to convey energy to the reaction not only during the ignition step, but also while it is occurring and even after its completion. In both approaches, however, the direct interaction of microwaves with the reaction mixture can lead to practically gradient-less heating profiles, on the basis of which the main observed characteristics and properties of the aforementioned reactions and products can be explained.

  18. Potensi Material Sampah Combustible pada Zona Pasif TPA Jatibarang Semarang sebagai Bahan Baku RDF (Refuse Derived Fuel

    Directory of Open Access Journals (Sweden)

    Irma Natasya Hutabarat

    2018-03-01

    Full Text Available Abstrak: Peningkatan jumlah timbulan sampah menyebabkan meningkatnya kebutuhan lahan pada TPA Jatibarang. Untuk menghindari terjadinya kekurangan lahan perlu dilakukan penanganan pada sampah yakni dengan mengubah sampah menjadi sumber energi seperti bahan baku RDF (Refused Derived Fuel. RDF merupakan salah satu teknik penanganan sampah dengan mengubah sampah menjadi sesuatu yang bermanfaat yaitu bahan bakar. Sampah tersebut dapat dimanfaatkan menjadi bahan baku RDF dengan cara menganalisis nilai kalor yang dihasilkan. Untuk menganalisis nilai kalor pada sampah combustible zona pasif TPA Jatibarang dapat dilakukan dengan cara pengujian sampel sebanyak 100 gram dengan alat bom kalorimeter. Sampel tersebut diambil pada kedalaman 0-3 m dengan metode random sampling. Kemudian akan didapat nilai kalor tinggi yang dihasilkan sampel tersebut. Nilai Kalor Tinggi yang dihasilkan sampel tersebut sebesar 5,25 kkal/ton pada kedalaman 0-1 m, 5,76 kkal/ton pada kedalaman 1-2 m dan 6,31 kkal/ton pada kedalaman 2-3 m. Nilai kalor tinggi yang dihasilkan sampah combustible tersebut menunjukkan bahwa semakin rendah kedalaman sampah maka akan semakin tinggi nilai kalor yang dihasilkan dan sampah tersebut berpotensi sebagai bahan baku RDF.

  19. Current situation regarding the co-combustion of waste materials in power plants; Aktuelle Situation der Mitverbrennung von Abfallstoffen in Kraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Schirmer, U.; Krueger, H.; Puch, K.H. [VGB Technische Vereinigung der Grosskraftwerksbetreiber e.V., Essen (Germany)

    1998-09-01

    In view of the wholly insufficient capacity, relative to current arisings, of waste incineration plants, residue processing plants and plants for the utilisation of other combustible materials we are inevitably faced with the question whether power plant furnaces might not be suited for the thermal treatment and utilisation of wastes and residues. This possibility has been studied by many VGB member companies and seriously investigated for its practicability in several cases. The investigations were premised on the following fundamental positions. The VGB members are prepared to contribute to the solution of the above problems as long as this is possible without detriment to their duties as energy suppliers. They can only assume this responsibility if the requirements of the licensing laws are observed. This concerns the quality and arising quantities of wastes to be taken in, emissions, and the disposal of combustion residues. Power plants typically make more or less complete use of their own process residues, a feature which as far as possible should not be impaired by the co-combustion process. The technical problems posed by the co-combustion of suitable residues and wastes are usually solvable. Co-combustion offers an alternative and a supplement to dedicated waste utilisation plants or plants for the utilisation of suitable residues. Beyond this some companies are interested in profiting from the fees that will be due to them for utilising wastes. From 1990 to 1992 a VGB working group studied the option of co-combustion on the basis of the above premises. The material elaborated by the group now in turn serves as a basis for the following deliberations. [Deutsch] Da die Kapazitaet der Abfallverbrennungsanlagen, der Anlagen zur Reststoffverwertung und der Anlagen zur Nutzung sonstiger brennbaren Stoffe fuer das vorhandene Angebot bei weitem nicht ausreicht, ergibt sich die Frage der Eignung von Kraftwerksfeuerungen zur thermischen Behandlung und Verwertung von

  20. Solution-combustion synthesized aluminium-doped spinel (LiAl(subx)Mn(sub2-x)O(sub4) as a high-performance lithium-ion battery cathode material

    CSIR Research Space (South Africa)

    Kebede, MA

    2015-06-01

    Full Text Available High-performing (LiAl(subx)Mn(sub2-x)O(sub4) (x = 0, 0.125, 0.25, 0.375, and 0.5) spinel cathode materials for lithium-ion battery were developed using a solution combustion method. The as-synthesized cathode materials have spinel cubic structure...

  1. Sandia Combustion Research Program

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, S.C.; Palmer, R.E.; Montana, C.A. (eds.)

    1988-01-01

    During the late 1970s, in response to a national energy crisis, Sandia proposed to the US Department of Energy (DOE) a new, ambitious program in combustion research. Shortly thereafter, the Combustion Research Facility (CRF) was established at Sandia's Livermore location. Designated a ''user facility,'' the charter of the CRF was to develop and maintain special-purpose resources to support a nationwide initiative-involving US inventories, industry, and national laboratories--to improve our understanding and control of combustion. This report includes descriptions several research projects which have been simulated by working groups and involve the on-site participation of industry scientists. DOE's Industry Technology Fellowship program, supported through the Office of Energy Research, has been instrumental in the success of some of these joint efforts. The remainder of this report presents results of calendar year 1988, separated thematically into eleven categories. Referred journal articles appearing in print during 1988 and selected other publications are included at the end of Section 11. Our traditional'' research activities--combustion chemistry, reacting flows, diagnostics, engine and coal combustion--have been supplemented by a new effort aimed at understanding combustion-related issues in the management of toxic and hazardous materials.

  2. Identification of β-SiC surrounded by relatable surrounding diamond ...

    Indian Academy of Sciences (India)

    β-SiC is identified in the presence of a relatable surrounding diamond medium using subtle, but discernible Raman ... Change in the nature of the surrounding material structure and its .... intensity implies very low graphite content in thin film. In.

  3. A Contribution to Turbulent Combustion: Premixed Flames and Material Surfaces Une contribution à la combustion turbulente : flammes prémélangées et surfaces des matériaux

    Directory of Open Access Journals (Sweden)

    Nicolleau F.

    2006-11-01

    Full Text Available The behavior of premixed flames has been examined by many authors. In fact the problem of combustion which develops in a turbulent medium depends on two scalings. One makes reference to the scales of the flame the other one is related to the turbulent field. Comparisons between these two scalings allow us to identified what sort of regime is expected. In this paper we first study the development of a material surface which may be identify with a flame front under rather severe conditions. An analytical approach is first used. Hereafter a numerical simulation will be introduced. The role of a fine grained turbulence is more active on the extension of the surface than large structures. To a large extent big eddies convey the surface without distorting it. The risks of extinction are generally predicted by making comparisons between the scales of the flame and the scales of the turbulent field starting from a direct simulation. Poinçot et al show that the smallest structures are not responsible for the extinction : intermediate structures are more efficient than the smallest ones. In a previous paper the role of these structures was examined : the distorting mechanism are acting in a cumulative way. The life time of the smallest structures is too short to have them playing a decive role in the extinction process. Intermediate sized structures are less active but they strain the flame during a longer period. This idea requires a detailed description of the turbulent field. That is made possible by using the ß model which accounts for the location of turbulent structures whose ranks in the whole sequence is termed n . The cumulative role of the velocity gradients is given as a function of n . The influence of the intermediate structure on the extinction process is thereby emphasized. Finally the ß model is also used to describe the domain of distributed combustion zones. Flames propagate in limited regions of space. These regions are disconnected

  4. Development, testing, and evaluation of MHD materials and component designs, Volume 3: Electrical properties of coal combustion product

    Science.gov (United States)

    Young, W. E.; Lempert, J.

    1980-11-01

    Laboratory apparatus was assembled to produce a plasma identical in composition and properties to that resulting in an MHD system when coal and air are burned. This was accomplished with a combustion chamber in which benzene, char, sulfur, and seed mixtures were burned with electrically preheated air. The plasma entered a measuring section where temperatures were measured with iridium versus iridium-rhodium thermocouples, with pyrometers, and by means of line reversal. Measurements of electrical conductivity were made with current and voltage probes. Many difficulties were experienced in the operation and calibration of the equipment, however, some readings were obtained in the 19000 C to 20000 C range, averaging 10 to 20 mhos/meter - much higher than predicted theoretically, probably due to electrical leakage. Electrical measurements were made on the Waltz Mill passage during operation. Readings less than 1.0 mhos/meter were obtained which was not unexpected because the plasma temperature approximated 21000 C.

  5. Stack gas desulfurization using adsorbent materials based on copper oxide; Desulfuracion de gases de combustion usando materiales adsorbentes basados en oxido de cobre

    Energy Technology Data Exchange (ETDEWEB)

    Flores Velazquez, Roberto; Rodas Grapain, Arturo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2008-07-01

    One of main fossil fuels used to date in Mexico for power generation is the fuel oil, with a total participation of 32%. The Mexican fuel oil is constituted in average by 84% in weight of carbon, 11% hydrogen, 0.4% nitrogen, 0.2% oxygen, 4% sulfur and the remaining is assumed to be metals such as vanadium, nickel, calcium, magnesium among others. The purpose of the present paper is to show a new route of preparation of materials impregnated through the application of ultrasonic energy and to evaluate its performance in the stack gas desulfurization. [Spanish] Uno de los principales combustibles fosiles empleados actualmente en Mexico para la generacion de energia electrica es el combustoleo, con una participacion total del 32%. El combustoleo mexicano esta constituido en promedio por 84% en peso de carbono, 11% de hidrogeno, 0.4% de nitrogeno, 0.2% de oxigeno, 4% de azufre y el resto se asume a metales como vanadio, niquel, calcio, magnesio entre otros. El proposito del presente trabajo es mostrar una nueva ruta de preparacion de materiales impregnados a traves de la aplicacion de energia ultrasonica y evaluar su desempeno en la desulfuracion de gases de combustion.

  6. Electrochemical and diffusional insights of combustion synthesized SrLi2Ti6O14 negative insertion material for Li-ion Batteries

    Science.gov (United States)

    Dayamani, Allumolu; Shinde, Ganesh S.; Chaupatnaik, Anshuman; Rao, R. Prasada; Adams, Stefan; Barpanda, Prabeer

    2018-05-01

    Solvothermal synthetic routes can provide energy-savvy platforms to fabricate battery anode materials involving relatively milder annealing steps vis-à-vis the conventional solid-state synthesis. These energy efficient routes in turn restrict aggressive grain growth to form nanoscale particles favouring efficient Li+ diffusion. Here, we report an economic solution combustion synthesis of SrLi2Ti6O14 anode involving nitrate-urea complexation with a short annealing duration of only 2 h (900 °C). Rietveld refinement confirms the phase purity of target product assuming an orthorhombic framework (Cmca symmetry). It delivers reversible capacity of ∼125 mAh.g-1 at a rate of C/20 involving a 1.38 V Ti4+/Ti3+ redox activity with excellent rate kinetics and cycling stability. Bond valence site energy (BVSE) calculations gauge SrLi2Ti6O14 to be an anisotropic 3D Li+ ion conductor with the highest ionic conductivity along the c direction. The electrochemical and diffusional pathways have been elucidated for combustion prepared SrLi2Ti6O14 as an efficient and safe negative electrode candidate for Li-ion batteries.

  7. Contribution to the study of nuclear fuel materials with a metallic uranium base; Contribution a l'etude des materiaux combustibles nucleaires a base d'uranium metallique

    Energy Technology Data Exchange (ETDEWEB)

    Englander, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-11-15

    In a power reactor destined to supply industrially recoverable thermal energy, the most economical source of heat still consists of natural metallic uranium. However, the nuclear fuel material, most often employed in the form of rods of 20 to 40 mm diameter, is subjected to a series of stresses which lead to irreversible distortions usually incompatible with the substructure of the reactor. As a result the fuel material must possess at the outset a certain number of qualities which must be determined. Investigations have therefore been carried out, first on the technological characters peculiar to each of the three allotropic phases of pure uranium metal, and on their interactions on the stabilisation of the material which consists of either cast uranium or uranium pile-treated in the {gamma} phase. (author) [French] Dans un reacteur de puissance destine a fournir de l'energie thermique industriellement recuperable, la source de chaleur la plus economique reste constituee par de l'uranium metallique naturel. Or, le materiau combustible nucleaire, employe le plus souvent sous forme de barreaux de 20 a 40 mm de diametre, se trouve soumis a un ensemble de contraintes qui provoque des deformations irreversibles, le plus souvent incompatibles avec l'infrastructure du reacteur. Par consequent, le materiau combustible doit presenter a l'origine un certain nombre de qualites qu'il est necessaire de determiner. Aussi a-t-on d'abord etudie les caracteres technologiques propres a chacune des trois phases allotropiques de l'uranium-metal pur et leurs interactions sur la stabilisation du materiau constitue soit par de l'uranium coule, soit par de l'uranium traite en pile en phase {gamma}. (auteur)

  8. Twenty-fifth symposium (international) on combustion

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Approximately two-thirds of the papers presented at this conference are contained in this volume. The other one-third appear in special issues of ''Combustion and Flame'', Vol. 99, 1994 and Vol. 100, 1995. Papers are divided into the following sections: Supersonic combustion; Detonations and explosions; Internal combustion engines; Practical aspects of combustion; Incineration and wastes; Sprays and droplet combustion; Coal and organic solids combustion; Soot and polycyclic aromatic hydrocarbons; Reaction kinetics; NO x ; Turbulent flames; Turbulent combustion; Laminar flames; Flame spread, fire and halogenated fire suppressants; Global environmental effects; Ignition; Two-phase combustion; Solid propellant combustion; Materials synthesis; Microgravity; and Experimental diagnostics. Papers have been processed separately for inclusion on the data base

  9. Combustion physics

    Science.gov (United States)

    Jones, A. R.

    1985-11-01

    Over 90% of our energy comes from combustion. By the year 2000 the figure will still be 80%, even allowing for nuclear and alternative energy sources. There are many familiar examples of combustion use, both domestic and industrial. These range from the Bunsen burner to large flares, from small combustion chambers, such as those in car engines, to industrial furnaces for steel manufacture or the generation of megawatts of electricity. There are also fires and explosions. The bountiful energy release from combustion, however, brings its problems, prominent among which are diminishing fuel resources and pollution. Combustion science is directed towards finding ways of improving efficiency and reducing pollution. One may ask, since combustion is a chemical reaction, why physics is involved: the answer is in three parts. First, chemicals cannot react unless they come together. In most flames the fuel and air are initially separate. The chemical reaction in the gas phase is very fast compared with the rate of mixing. Thus, once the fuel and air are mixed the reaction can be considered to occur instantaneously and fluid mechanics limits the rate of burning. Secondly, thermodynamics and heat transfer determine the thermal properties of the combustion products. Heat transfer also plays a role by preheating the reactants and is essential to extracting useful work. Fluid mechanics is relevant if work is to be performed directly, as in a turbine. Finally, physical methods, including electric probes, acoustics, optics, spectroscopy and pyrometry, are used to examine flames. The article is concerned mainly with how physics is used to improve the efficiency of combustion.

  10. Producer for vegetal combustibles for internal-combustion motors

    Energy Technology Data Exchange (ETDEWEB)

    1943-12-28

    A producer is described for internal-combustion motors fed with wood or agricultural byproducts characterized by the fact that its full operation is independent of the degree of wetness of the material used.

  11. Furnace for degasification and gasification of combustibles rich in ashes

    Energy Technology Data Exchange (ETDEWEB)

    1952-05-13

    A furnace is described for the degasification and the gasification of combustibles rich in ashes with continuous-functioning vertical chambers of transversal rectangular sections in which the washing gas flows from one side to the other, traversing the combustible, characterized by the fact that the height of the combustible surrounded by the washing gas stays in a proportion higher than 10:1 to the thickness of the width of combustible.

  12. Luminescence properties of ZnMoO{sub 4}:Eu{sup 3+}:Y{sup 3+} materials synthesized by solution combustion synthesis method

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Naveen, E-mail: vermanaveen17@gmail.com; Singh, Krishan Chander; Jindal, Jitender; Yadav, Suprabha [Department of chemistry, Maharshi Dayanand University, Rohtak-124001 – India (India); Mari, Bernabe; Mollar, Miguel [Institut de Disseny per la Fabricació Automatitzada - Departament de Física Aplicada, Universitat Politècnica de València, Camí de Vera s/n, 46022 València (Spain)

    2016-04-13

    The Zn{sub (1-x-y)}MoO{sub 4}:Eu{sup 3+}{sub (x)}: Y{sup 3+}{sub (y)} (x = 1 mol% and y = 1 or 2 mol%) compounds were prepared by combustion synthesis method. The crystal structure of the samples was identified by X-ray diffraction (XRD). The photoluminescence properties were investigated and it is observed that the co-doping of Y{sup 3+} enhances the luminescence emission intensity of ZnMoO{sub 4}:Eu{sup 3+} material. The Y{sup 3+} acts as a sensitizer in the ZnMoO{sub 4}:Eu{sup 3+} lattice. The particle size is calculated from XRD data by using Scherer Equation. The particles has been found in the range of 30-40 nm.

  13. One-step solution combustion synthesis of Fe{sub 2}O{sub 3}/C nano-composites as anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Li, Peiyang; Deng, Jiachun; Li, Ying [Nano-Energy Inorganic Materials Laboratory, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Liang, Wei, E-mail: liangwei@tyut.edu.cn [Nano-Energy Inorganic Materials Laboratory, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Wang, Kun [Nano-Energy Inorganic Materials Laboratory, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Kang, Litao, E-mail: kangltxy@gmail.com [Nano-Energy Inorganic Materials Laboratory, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Zeng, Shaozhong; Yin, Shanhui; Zhao, Zhigang [Chery Automobile Co. Ltd., Wuhu 241006 (China); Liu, Xuguang; Yang, Yongzhen [College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Gao, Feng [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China)

    2014-03-25

    Highlights: • Fe{sub 2}O{sub 3}/C composite anode materials were prepared by a solution combustion process. • The carbon content could be adjusted by regulating the ratio of oxidizer/fuel. • The Fe{sub 2}O{sub 3}/C composite showed capacity 470 mA h g{sup −1} at the 80th cycle at 125 mA g{sup −1}. -- Abstract: This article describes a one-step solution combustion route (within 30 min at 350 °C in air) to prepare Fe{sub 2}O{sub 3} anode materials for lithium ion batteries (LIBs) from Fe(NO{sub 3}){sub 3}⋅9H{sub 2}O solution with citric acid. XRD, SEM-EDX and TEM showed that the product consisted a mixture of nano-sized α-Fe{sub 2}O{sub 3} and γ-Fe{sub 2}O{sub 3} crystals that agglomerated into porous particles. Significantly, in situ formed carbon could be introduced into the product (i.e., Fe{sub 2}O{sub 3}/C nano-composites) by simply increasing the dosage of citric acid in the precursor solution. The as-prepared Fe{sub 2}O{sub 3}/C nano-composite exhibited high reversible capacities of 470 and 419 mA h g{sup −1} at the 80th and 200th cycles with a current density of 125 mA g{sup −1}, which are much higher than those of counterparts without carbon (i.e., Fe{sub 2}O{sub 3} nano-particles). Comparison experiments correlated with the performance improvement of Fe{sub 2}O{sub 3}/C nano-composites with in situ formed carbon, well-developed mesopores and relatively high specific surface areas.

  14. Assessment of structural integrity of Monju steel liner against sodium leakage and combustion. Strain criterion of the liner material

    Energy Technology Data Exchange (ETDEWEB)

    Asayama, T.; Koi, M. [Japan Nuclear Cycle Development Institute, Ibaraki (Japan)

    2001-07-01

    In a postulated condition of sodium leakage and combustion in the secondary heat transfer system of the prototype Japanese fast breeder reactor Monju, thermal stresses raise in steel liners installed to prevent sodium from contacting to concrete. Excessive strain due to the thermal stresses leads to failure of the liner. This paper proposes a strain criterion below that the mechanical integrity of liner is assured. In-plane thermal expansion causes membrane strain and out-of-plane expansion causes bending strain. Therefore, failure modes to be taken into account are tensile fracture and bending fracture. The strain criterion can be determined based on tensile and bending tests. Tensile tests and three-point bending tests were performed at the temperature range from room temperature to 1000 C. Fracture elongation was measured in both tests. Uniform elongation was also measured in tensile tests. Various factors that can affect the above experimental results, multi-axiality, environmental effects, and creep were examined. Based on the above results, the strain criterion was determined. The criterion is 10% for membrane strain and 30% for membrane plus bending strain in the temperature range of 350 C to 1000 C. For the temperatures less than 350 C, the half of those values is used. (author)

  15. PROSPECTS OF MANUFACTURE OF PISTON RINGS INTERNAL COMBUSTION ENGINES OF POWDER MATERIALS ON THE BASE OF IRON

    Directory of Open Access Journals (Sweden)

    B. M. Musaibov

    2013-01-01

    Full Text Available Development and production of piston rings made of sintered materials on the basis of iron powder metallurgy is an innovative way. In the application of this technology reduces the consumption of material and costs for the production of piston rings 30-40% in comparison with the traditional methods of their manufacture

  16. Combustion 2000

    Energy Technology Data Exchange (ETDEWEB)

    A. Levasseur; S. Goodstine; J. Ruby; M. Nawaz; C. Senior; F. Robson; S. Lehman; W. Blecher; W. Fugard; A. Rao; A. Sarofim; P. Smith; D. Pershing; E. Eddings; M. Cremer; J. Hurley; G. Weber; M. Jones; M. Collings; D. Hajicek; A. Henderson; P. Klevan; D. Seery; B. Knight; R. Lessard; J. Sangiovanni; A. Dennis; C. Bird; W. Sutton; N. Bornstein; F. Cogswell; C. Randino; S. Gale; Mike Heap

    2001-06-30

    . To achieve these objectives requires a change from complete reliance of coal-fired systems on steam turbines (Rankine cycles) and moving forward to a combined cycle utilizing gas turbines (Brayton cycles) which offer the possibility of significantly greater efficiency. This is because gas turbine cycles operate at temperatures well beyond current steam cycles, allowing the working fluid (air) temperature to more closely approach that of the major energy source, the combustion of coal. In fact, a good figure of merit for a HIPPS design is just how much of the enthalpy from coal combustion is used by the gas turbine. The efficiency of a power cycle varies directly with the temperature of the working fluid and for contemporary gas turbines the optimal turbine inlet temperature is in the range of 2300-2500 F (1260-1371 C). These temperatures are beyond the working range of currently available alloys and are also in the range of the ash fusion temperature of most coals. These two sets of physical properties combine to produce the major engineering challenges for a HIPPS design. The UTRC team developed a design hierarchy to impose more rigor in our approach. Once the size of the plant had been determined by the choice of gas turbine and the matching steam turbine, the design process of the High Temperature Advanced Furnace (HITAF) moved ineluctably to a down-fired, slagging configuration. This design was based on two air heaters: one a high temperature slagging Radiative Air Heater (RAH) and a lower temperature, dry ash Convective Air Heater (CAH). The specific details of the air heaters are arrived at by an iterative sequence in the following order:-Starting from the overall Cycle requirements which set the limits for the combustion and heat transfer analysis-The available enthalpy determined the range of materials, ceramics or alloys, which could tolerate the temperatures-Structural Analysis of the designs proved to be the major limitation-Finally the commercialization

  17. Biofuels combustion.

    Science.gov (United States)

    Westbrook, Charles K

    2013-01-01

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly.

  18. New high-nitrogen materials based on nitroguanyl-tetrazines: explosive properties, thermal decomposition and combustion studies

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, David E.; Tappan, Bryce C.; Hiskey, Michael A.; Son, Steve F.; Harry, Herbert; Montoya, Dennis; Hagelberg, Stephanie [Dynamic Experimentation Division, DX-2 Materials Dynamics Group, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2005-12-01

    This paper describes the explosive sensitivity and performance properties of two novel high-nitrogen materials, 3,6-bis-nitroguanyl-1,2,4,5-tetrazine (1, (NQ{sub 2}Tz)) and its corresponding bis-triaminoguanidinium salt (2, (TAG){sub 2}(NQ){sub 2}Tz). These materials exhibit very low pressure dependence in burning rate. Flash pyrolysis/FTIR spectroscopy was performed, and insight into this interesting burning behavior was obtained. Our studies indicate that 1 and 2 exhibit highly promising energetic materials properties. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  19. Thermal and mechanical behaviour of oxygen carrier materials for chemical looping combustion in a packed bed reactor

    International Nuclear Information System (INIS)

    Jacobs, M.; Van Noyen, J.; Larring, Y.; Mccann, M.; Pishahang, M.; Amini, S.; Ortiz, M.; Galluci, F.; Sint-Annaland, M.V.; Tournigant, D.; Louradour, E.; Snijkers, F.

    2015-01-01

    Highlights: • Ilmenite-based oxygen carriers were developed for packed-bed chemical looping. • Addition of Mn_2O_3 increased mechanical strength and microstructure of the carriers. • Oxygen carriers were able to withstand creep and thermal cycling up to 1200 °C. • Ilmenite-based granules are a promising shape for packed-bed reactor conditions. - Abstract: Chemical looping combustion (CLC) is a promising carbon capture technology where cyclic reduction and oxidation of a metallic oxide, which acts as a solid oxygen carrier, takes place. With this system, direct contact between air and fuel can be avoided, and so, a concentrated CO_2 stream is generated after condensation of the water in the exit gas stream. An interesting reactor system for CLC is a packed bed reactor as it can have a higher efficiency compared to a fluidized bed concept, but it requires other types of oxygen carrier particles. The particles must be larger to avoid a large pressure drop in the reactor and they must be mechanically strong to withstand the severe reactor conditions. Therefore, oxygen carriers in the shape of granules and based on the mineral ilmenite were subjected to thermal cycling and creep tests. The mechanical strength of the granules before and after testing was investigated by crush tests. In addition, the microstructure of these oxygen particles was studied to understand the relationship between the physical properties and the mechanical performance. It was found that the granules are a promising shape for a packed bed reactor as no severe degradation in strength was noticed upon thermal cycling and creep testing. Especially, the addition of Mn_2O_3 to the ilmenite, which leads to the formation of an iron–manganese oxide, seems to results in stronger granules than the other ilmenite-based granules.

  20. Numerical and experimental study of the influence of the operational parameters on the formation mechanisms of oxides of nitrogen during the combustion of mixtures of cellulosic and plastic materials; Etude experimentale et numerique de l'influence des parametres operatoires sur les mecanismes de formation des oxydes d'azote lors de la combustion de melanges de materiaux cellulosiques et plastiques

    Energy Technology Data Exchange (ETDEWEB)

    Andzi Barhe, T.

    2004-10-15

    The current thesis was performed within a collaboration between the Laboratoire de Combustion et de Detonique (LCD of the University of Poitiers) and the Laboratoire de Physique et de Chimie d'Environnement (LPCE) of the University of Ouagadougou. It was financed by Agency for Environment and Energy Management (ADEME). The principle object of this study is the optimisation of the combustion process during the incineration of waste. This optimisation is aimed at the reduction of the polluting emissions, principally CO and NO, during the incineration of cellulosic and plastic materials. It involves the analysis of the influence of the operational parameters on the polluting emissions and the control of reaction mechanisms of formation and reduction of these pollutants during the combustion process. Consequently, the study was performed in two parts: an experimental part and a numerical part. The experimental part was realised using a fixed bed counterflow reactor. This setup simulates the combustion within an industrial waste incinerator. The reactor allows the combustion of a vertical layer of waste mixture (wood, cardboard, PET, polyamide) to be followed. Three model mixtures representative of the makeup of household waste were studied in order to determine the influence of the composition of the waste on the emission of pollutants (CO and NO). The obtained results show that this parameter has a practically negligible influence within the tested parameter range. Consequently the formation of pollutants depends on the operating parameters - the equivalence ratio and the temperature. A numerical study of the influence of these parameters in order to show their impact on the mechanisms of pollutant formation and to determine the chemical mechanisms involved in the formation of oxides of nitrogen. The numerical study was performed with software developed at the LCD. This programme based on a detailed chemical model coupled to a simple physical model. It uses the

  1. Combustion means for solid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Murase, D.

    1987-09-23

    A combustion device for solid fuel, suitable for coal, coke, charcoal, coal-dust briquettes etc., comprising:- a base stand with an opening therein, an imperforate heat resistant holding board locatable to close said opening; a combustion chamber standing on the base stand with the holding board forming the base of the combustion chamber; a wiper arm pivoted for horizontal wiping movement over the upper surface of the holding board; an inlet means at a lower edge of said chamber above the base stand, and/or in a surrounding wall of said chamber, whereby combustion air may enter as exhaust gases leave the combustion chamber; an exhaust pipe for the exhaust gases; generally tubular gas-flow heat-exchange ducting putting the combustion chamber and exhaust pipe into communication; and means capable of moving the holding board into and out of the opening for removal of ash or other residue. The invention can be used for a heating system in a house or in a greenhouse or for a boiler.

  2. High-resolution transmission electron microscopy studies of graphite materials prepared by high-temperature treatment of unburned carbon concentrates from combustion fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    Miguel Cabielles; Jean-Nol Rouzaud; Ana B. Garcia [Instituto Nacional del Carbn (INCAR), Oviedo (Spain)

    2009-01-15

    High-resolution transmission electron microscopy (HRTEM) has been used in this work to study the microstructural (structure and microtexture) changes occurring during the high-temperature treatment of the unburned carbon concentrates from coal combustion fly ashes. Emphasis was placed on two aspects: (i) the development of graphitic carbon structures and (ii) the disordered carbon forms remaining in the graphitized samples. In addition, by coupling HRTEM with energy-dispersive spectroscopy, the transformations with the temperature of the inorganic matter (mainly iron- and silicon-based phases) of the unburned carbon concentrates were evidenced. The HRTEM results were compared to the averaged structural order of the materials as evaluated by X-ray diffraction (XRD) and Raman spectroscopy. As indicated by XRD and Raman parameters, more-ordered materials were obtained from the unburned carbon concentrates with higher mineral/inorganic matter, thus inferring the catalytic effect of some of their components. However, the average character of the information provided by these instrumental techniques seems to be inconclusive in discriminating between carbon structures with different degrees of order (stricto sensu graphite, graphitic, turbostratic, etc.) in a given graphitized unburned carbon. Unlike XRD and Raman, HRTEM is a useful tool for imaging directly the profile of the polyaromatic layers (graphene planes), thus allowing the sample heterogeneity to be looked at, specifically the presence of disordered carbon phases. 49 refs., 9 figs., 3 tabs.

  3. Characteristics of oil sludge from crude oil terminal and behaviors of the naturally occurring radioactive materials and heavy metals on combustion of the sludge

    International Nuclear Information System (INIS)

    Mohamad Puad Abu

    2001-01-01

    The study on the characteristics and behaviors of Naturally Occurring Radioactive Materials (NORM) and heavy metals (HM) in the oil sludge from the crude oil terminal were performed using Gamma Spectroscopy (GM), Neutron Activation Analysis Instrumental (NAAI) and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). GM and NAAI were used to analyze the concentrations of radionuclides whereas NAAI as well as ICP-MS techniques were applied for HM. The samples were then combusted at temperature ranging from 100 degree Celsius - 800 degree Celsius for a period of 30-150 minutes. The ashes produced were then analyzed again for the various elemental concentrations by the above techniques. The percentage of volatilization was then derived mathematically. The concentration of Ra-226 (123 Bq/ kg) and Ra-228 (117 Bq/ kg) in the oil sludge are higher compared with their parent U-238 (32.12 Bq/ kg) and Th-232 (35.36 Bq/ kg). The concentration of HM such as As (13.30 ppm), Cr (46 ppm) and Zn (4287 ppm) in the oil sludge are also higher compared with As (7.5 ppm), Cr (43 ppm) and Zn (36 ppm) contain in the Malaysian normal soil. The heating value for crude oil sludge is 9000 kJ/ kg which is below the value for self-sustaining combustion (11000 kJ/ kg). The percentage of volatilization varies from 2-70 % depends on the elements, temperature and period of combustion. Uranium was found to volatile more than other elements. Higher temperatures (>500 degree Celsius) and longer exposure time (>90 minutes) promoted metal and radionuclide volatilization significantly more than 20 %. Based on the first order kinetic reaction, a new global mathematical model was developed (Q e =1-e -k e t ). This model can predict the percentage of volatilization for the various elements contain in the sludge if the temperature and time of combustion are known. With this known percentage of volatilization, the concentration of various elements present in the bottom and fly ashes can be deduced. From

  4. Use of co-combustion bottom ash to design an acoustic absorbing material for highway noise barriers.

    Science.gov (United States)

    Arenas, Celia; Leiva, Carlos; Vilches, Luis F; Cifuentes, Héctor

    2013-11-01

    The present study aims to determine and evaluate the applicability of a new product consisting of coal bottom ash mixed with Portland cement in the application of highway noise barriers. In order to effectively recycle the bottom ash, the influence of the grain particle size of bottom ash, the thickness of the panel and the combination of different layers with various particle sizes have been studied, as well as some environmental properties including leachability (EN-12457-4, NEN-7345) and radioactivity tests. Based on the obtained results, the acoustic properties of the final composite material were similar or even better than those found in porous concrete used for the same application. According to this study, the material produced presented no environmental risk. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Hydrogen like energy and materials for fuel cells; Hidrogeno como energetico y materiales para celdas de combustible

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez V, S. M., E-mail: suilma.fernandez@inin.gob.m [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2010-07-01

    The researches on the production, storage and the use of hydrogen like fuel or energy carrying are carried out in several laboratories around the world. In the Instituto Nacional de Investigaciones Nucleares (ININ), from the year of 1993 they are carried out researches about the synthesis of electro-catalysts materials than can serve in the hydrogen production starting from the electrolysis of the water, or in fuel cells, as well as of semiconductor materials for the photo-electrolysis of the water. Recently, in collaboration with other Departments of the ININ, the hydrogen production has been approached starting from fruit and vegetable wastes, with the purpose of evaluating the possibility that this residuals can be utilized for the energy obtaining and that they are not only garbage that causes problems of environmental pollution, generate toxic gases and pollute the soil with the organic acids that take place during their fermentation. (Author)

  6. AlSi17Cu5Mg alloy as future material for castings of pistons for internal combustion engines

    Directory of Open Access Journals (Sweden)

    J. Piątkowski

    2015-07-01

    Full Text Available The paper presents chosen properties and microstructure of AlSi17Cu5Mg alloy as future material for casting pistons in automotive industry. Tests were conducted to elaborate technology of preparation, assessment of crystallisation parameters and shaping the primary structure of the silumin with the aim to improve the working parameters and the functioning efficiency in cylinder-piston system. Refinement of Si crystals, achieved due to overheating above the temperature Tliq. causes that the alloy reaches satisfactory properties in working chamber of the engine are optimised. Such condition of material characteristics causes that hypereutectic silumins, for chosen applications in transport, may serve as an alternative to Al - Si alloys of hypoeutectic and near - eutectic type.

  7. An Assessment of the Fire Safety Hazard Associated with External Fire Spread in Tall Buildings with Combustible Façade Material

    DEFF Research Database (Denmark)

    Lavard Brogaard, Nicholas; Torero, Jose L.; Jomaas, Grunde

    2014-01-01

    in order to obtain a conclusive assessment of the fire safety hazards associated with combustible facades. Prescriptive fire safety codes are typically not allowing any type of combustible façade in buildings that are taller than 2-3 stories. However, a performance based approach does not contain height...

  8. Fly ashes from co-combustion as a filler material in concrete production; Anvaendning av energiaskor som fillermaterial vid betongtillverkning

    Energy Technology Data Exchange (ETDEWEB)

    Sundblom, Hillevi

    2004-01-01

    The Swedish concrete producers have decided to work towards a common goal to limit the production of concrete with naturally rounded aggregate. A consequence is when use of a substitute, crushed aggregate, the demand of filler material increases. During the last years ashes form the CFB boiler in Perstorp has been utilised as a filler material, with success, in concrete production at Sydsten, Malmoe, Sweden. To examine the potential of using Swedish fly ashes as a filler material in concrete production, have different Swedish fly ashes above been studied to see if they fit the requirements for a filler material. The fly ashes studied in the project can be divided into four different groups, considering fuel mix and boiler type; 1. Bio and sludge fired CFB/BFB boiler from the paper industry, 2. Bio and peat fired CFB/BFB boiler, 3. Pulverized peat/coal firing furnace, 4.Bio and peat fired grate-fired boiler. From Sydsten experiences of using Swedish fly ashes two demands have emerged concerning the chemical composition of the ashes. The total amount of chloride in the concrete should not be higher than 0,1% and the LOI, (Loss Of Ignition) must be less than 10 %. The different ash analyses showed that the fluidised bed boilers and pulverized firing furnaces, in this study, passed all the chemical requirements but the grate fire boilers had difficulties to fulfil the requirement of LOI. The ashes chosen to be studied in further rheological investigations in different fresh concrete mixtures were, Category 1 (Hallstavik's and Hyltebruk's papermill), Category 2 (Vaesteraas Vaermeverk och Vaertaverket) and from Category 3 (Vattenfall Vaerme Uppsala). The results presented an increased water consumption of ashes from paper mills comparing with the other ashes, a probable reason could be the shape of the ash grains. The experiments also showed that all ashes contributed to the final strength of the hardened concrete, the paper mill ashes also contributed to the

  9. Tubular combustion

    CERN Document Server

    Ishizuka, Satoru

    2014-01-01

    Tubular combustors are cylindrical tubes where flame ignition and propagation occur in a spatially confined, highly controlled environment, in a nearly flat, elongated geometry. This allows for some unique advantages where extremely even heat dispersion is required over a large surface while still maintaining fuel efficiency. Tubular combustors also allow for easy flexibility in type of fuel source, allowing for quick changeover to meet various needs and changing fuel pricing. This new addition to the MP sustainable energy series will provide the most up-to-date research on tubular combustion--some of it only now coming out of private proprietary protection. Plentiful examples of current applications along with a good explanation of background theory will offer readers an invaluable guide on this promising energy technology. Highlights include: * An introduction to the theory of tubular flames * The "how to" of maintaining stability of tubular flames through continuous combustion * Examples of both small-scal...

  10. Use of co-combustion bottom ash to design an acoustic absorbing material for highway noise barriers

    International Nuclear Information System (INIS)

    Arenas, Celia; Leiva, Carlos; Vilches, Luis F.; Cifuentes, Héctor

    2013-01-01

    Highlights: • The particle size of bottom ash influenced the acoustic behavior of the barrier. • The best sound absorption coefficients were measured for larger particle sizes. • The maximum noise absorption is displaced to lower frequencies for higher thickness. • A noise barrier was designed with better properties than commercial products. • Recycling products from bottom ash no present leaching and radioactivity problems. - Abstract: The present study aims to determine and evaluate the applicability of a new product consisting of coal bottom ash mixed with Portland cement in the application of highway noise barriers. In order to effectively recycle the bottom ash, the influence of the grain particle size of bottom ash, the thickness of the panel and the combination of different layers with various particle sizes have been studied, as well as some environmental properties including leachability (EN-12457-4, NEN-7345) and radioactivity tests. Based on the obtained results, the acoustic properties of the final composite material were similar or even better than those found in porous concrete used for the same application. According to this study, the material produced presented no environmental risk

  11. Use of co-combustion bottom ash to design an acoustic absorbing material for highway noise barriers

    Energy Technology Data Exchange (ETDEWEB)

    Arenas, Celia; Leiva, Carlos; Vilches, Luis F. [University of Seville, School of Industrial Engineering, Department of Chemical and Environmental Engineering, Camino de los Descubrimientos s/n, E-41092 Seville (Spain); Cifuentes, Héctor, E-mail: bulte@us.es [University of Seville, School of Industrial Engineering, Continuum Mechanics and Structural Analysis Department, Camino de los Descubrimientos s/n, E-41092 Seville (Spain)

    2013-11-15

    Highlights: • The particle size of bottom ash influenced the acoustic behavior of the barrier. • The best sound absorption coefficients were measured for larger particle sizes. • The maximum noise absorption is displaced to lower frequencies for higher thickness. • A noise barrier was designed with better properties than commercial products. • Recycling products from bottom ash no present leaching and radioactivity problems. - Abstract: The present study aims to determine and evaluate the applicability of a new product consisting of coal bottom ash mixed with Portland cement in the application of highway noise barriers. In order to effectively recycle the bottom ash, the influence of the grain particle size of bottom ash, the thickness of the panel and the combination of different layers with various particle sizes have been studied, as well as some environmental properties including leachability (EN-12457-4, NEN-7345) and radioactivity tests. Based on the obtained results, the acoustic properties of the final composite material were similar or even better than those found in porous concrete used for the same application. According to this study, the material produced presented no environmental risk.

  12. Advanced Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, Gordon R. [NETL

    2013-03-11

    The activity reported in this presentation is to provide the mechanical and physical property information needed to allow rational design, development and/or choice of alloys, manufacturing approaches, and environmental exposure and component life models to enable oxy-fuel combustion boilers to operate at Ultra-Supercritical (up to 650{degrees}C & between 22-30 MPa) and/or Advanced Ultra-Supercritical conditions (760{degrees}C & 35 MPa).

  13. Molten salt combustion of radioactive wastes

    International Nuclear Information System (INIS)

    Grantham, L.F.; McKenzie, D.E.; Richards, W.L.; Oldenkamp, R.D.

    1976-01-01

    The Atomics International Molten Salt Combustion Process reduces the weight and volume of combustible β-γ contaminated transuranic waste by utilizing air in a molten salt medium to combust organic materials, to trap particulates, and to react chemically with any acidic gases produced during combustion. Typically, incomplete combustion products such as hydrocarbons and carbon monoxide are below detection limits (i.e., 3 ) is directly related to the sodium chloride vapor pressure of the melt; >80% of the particulate is sodium chloride. Essentially all metal oxides (combustion ash) are retained in the melt, e.g., >99.9% of the plutonium, >99.6% of the europium, and >99.9% of the ruthenium are retained in the melt. Both bench-scale radioactive and pilot scale (50 kg/hr) nonradioactive combustion tests have been completed with essentially the same results. Design of three combustors for industrial applications are underway

  14. Sodium nitrate combustion limit tests

    International Nuclear Information System (INIS)

    Beitel, G.A.

    1976-04-01

    Sodium nitrate is a powerful solid oxidant. Energetically, it is capable of exothermically oxidizing almost any organic material. Rate-controlling variables such as temperature, concentration of oxidant, concentration of fuel, thermal conductivity, moisture content, size, and pressure severely limit the possibility of a self-supported exothermic reaction (combustion). The tests reported in this document were conducted on one-gram samples at atmospheric pressure. Below 380 0 C, NaNO 3 was stable and did not support combustion. At moisture concentrations above 22 wt percent, exothermic reactions did not propagate in even the most energetic and reactive compositions. Fresh resin and paraffin were too volatile to enable a NaNO 2 -supported combustion process to propagate. Concentrations of NaNO 3 above 95 wt percent or below 35 wt percent did not react with enough energy release to support combustion. The influence of sample size and confining pressure, both important factors, was not investigated in this study

  15. Nitrogen oxides in the combustion products of gas cookers

    Energy Technology Data Exchange (ETDEWEB)

    Benes, M.; Zahourek, J.

    1981-07-01

    The combustion of town gas and natural gas in two types of gas ranges manufactured in Czechoslovakia resulted in measurable amounts of NO/sub x/ in both the combustion products and the surrounding air. In all the cases tested, the amounts of NO/sub x/ given off exceeded levels permitted by current Czech standards. These results indicate that before the widespread use of any new gas ranges, their combustion products should be tested for NO/sub x/.

  16. High Combustion Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — At NETL's High-Pressure Combustion Research Facility in Morgantown, WV, researchers can investigate new high-pressure, high-temperature hydrogen turbine combustion...

  17. Combustion Research Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Combustion Research Laboratory facilitates the development of new combustion systems or improves the operation of existing systems to meet the Army's mission for...

  18. Combustion chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N.J. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

  19. Issues in waste combustion

    Energy Technology Data Exchange (ETDEWEB)

    Gustavsson, Lennart; Robertson, Kerstin; Tullin, Claes [Swedish National Testing and Research Inst., Boraas (Sweden); Sundquist, Lena; Wrangensten, Lars [AaF-Energikonsult AB, Stockholm (Sweden); Blom, Elisabet [AaF-Processdesign AB, Stockholm (Sweden)

    2003-05-01

    The main purpose of this review is to provide an overview of the state-of-the-art on research and development issues related to waste combustion with relevance for Swedish conditions. The review focuses on co-combustion in grate and fluidised bed furnaces. It is primarily literature searches in relevant databases of scientific publications with to material published after 1995. As a complement, findings published in different report series, have also been included. Since the area covered by this report is very wide, we do not claim to cover the issues included completely and it has not been possitile to evaluate the referred studies in depth. Basic knowledge about combustion issues is not included since such information can be found elsewhere in the literature. Rather, this review should be viewed as an overview of research and development in the waste-to-energy area and as such we hope that it will inspire scientists and others to further work in relevant areas.

  20. 30 CFR 57.4104 - Combustible waste.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Combustible waste. 57.4104 Section 57.4104... Control Prohibitions/precautions/housekeeping § 57.4104 Combustible waste. (a) Waste materials, including liquids, shall not accumulate in quantities that could create a fire hazard. (b) Waste or rags containing...

  1. Circumstances surrounding aneurysmal subarachnoid hemorrhage

    NARCIS (Netherlands)

    Schievink, W. I.; Karemaker, J. M.; Hageman, L. M.; van der Werf, D. J.

    1989-01-01

    The circumstances surrounding aneurysmal subarachnoid hemorrhage were investigated in a group of 500 consecutive patients admitted to a neurosurgical center. Subarachnoid hemorrhage occurred during stressful events in 42.8% of the patients, during nonstrenuous activities in 34.4%, and during rest or

  2. Rotary combustion device

    NARCIS (Netherlands)

    2008-01-01

    Rotary combustion device (1) with rotary combustion chamber (4). Specific measures are taken to provide ignition of a combustible mixture. It is proposed that a hollow tube be provided coaxially with the axis of rotation (6), so that a small part of the mixture is guided into the combustion chamber.

  3. Lung function and airway inflammation in rats following exposure to combustion products of carbon-graphite/epoxy composite material: comparison to a rodent model of acute lung injury.

    Science.gov (United States)

    Whitehead, Gregory S; Grasman, Keith A; Kimmel, Edgar C

    2003-02-01

    Pulmonary function and inflammation in the lungs of rodents exposed by inhalation to carbon/graphite/epoxy advanced composite material (ACM) combustion products were compared to that of a rodent model of acute lung injury (ALI) produced by pneumotoxic paraquat dichloride. This investigation was undertaken to determine if short-term exposure to ACM smoke induces ALI; and to determine if smoke-related responses were similar to the pathogenic mechanisms of a model of lung vascular injury. We examined the time-course for mechanical lung function, infiltration of inflammatory cells into the lung, and the expression of three inflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha), macrophage inflammatory protein-2 (MIP-2) and interferon-gamma (IFN-gamma). Male Fischer-344 rats were either exposed to 26.8-29.8 g/m(3) nominal concentrations of smoke or were given i.p. injections of paraquat dichloride. Measurements were determined at 1, 2, 3, and 7 days post exposure. In the smoke-challenged rats, there were no changes in lung function indicative of ALI throughout the 7-day observation period, despite the acute lethality of the smoke atmosphere. However, the animals showed signs of pulmonary inflammation. The expression of TNF-alpha was significantly increased in the lavage fluid 1 day following exposure, which preceded the maximum leukocyte infiltration. MIP-2 levels were significantly increased in lavage fluid at days 2, 3, and 7. This followed the leukocyte infiltration. IFN-gamma was significantly increased in the lung tissue at day 7, which occurred during the resolution of the inflammatory response. The paraquat, which was also lethal to a small percentage of the animals, caused several physiologic changes characteristic of ALI, including significant decreases in lung compliance, lung volumes/capacities, distribution of ventilation, and gas exchange capacity. The expression of TNF-alpha and MIP-2 increased significantly in the lung tissue as well as in the

  4. Co-combustion of cultivable raw materials in existing power supply plants -a study on the potential for such plants in the eastern Laender. Final report

    International Nuclear Information System (INIS)

    Grosskopf, W.; Kappelmann, K.H.

    1996-04-01

    The present study is dedicated to an analysis of co-combustion of biomass in existing power supply plants in the eastern Laender. The question to be resolved is whether the existing substantial potential for substituting fossil energy carriers for biomass in the short term and at low cost also offers a viable option from the viewpoint of political economy. In its final assessment the study also takes agropolitical and ecopolitical interests into account. A further basic question posed by this impact analysis is in what way the increased use of biomass as an energy carrier can contribute to farmers; income and thus help improve employment in rural area. Implicated in this is the question whether the conservation of developed land resulting from large-area biomass cultivation is desirable from the sociopolitical viewpoint. Another important aspect concerning the impact analysis is the question as to the environmental efficiency of biomass co-combustion given the Federal Government's aims regarding CO 2 abatement. The study examines how biomas co-combustion compares with other alternatives to this end in terms of CO 2 abatement costs. These deliberations provide the basis for the study's concluding recommendations to political decision makers who are confronted with the question whether and under what conditions public promotion of biomass co-combustion in the new Laender makes sociopolitical sense. (orig./SR) [de

  5. Solid waste combustion for alpha waste incineration

    International Nuclear Information System (INIS)

    Orloff, D.I.

    1981-02-01

    Radioactive waste incinerator development at the Savannah River Laboratory has been augmented by fundamental combustion studies at the University of South Carolina. The objective was to measure and model pyrolysis and combustion rates of typical Savannah River Plant waste materials as a function of incinerator operating conditions. The analytical models developed in this work have been incorporated into a waste burning transient code. The code predicts maximum air requirement and heat energy release as a function of waste type, package size, combustion chamber size, and temperature. Historically, relationships have been determined by direct experiments that did not allow an engineering basis for predicting combustion rates in untested incinerators. The computed combustion rates and burning times agree with measured values in the Savannah River Laboratory pilot (1 lb/hr) and full-scale (12 lb/hr) alpha incinerators for a wide variety of typical waste materials

  6. Introduction to Physics and Chemistry of Combustion Explosion, Flame, Detonation

    CERN Document Server

    Liberman, Michael A

    2008-01-01

    Most of the material covered in this book deals with the fundamentals of chemistry and physics of key processes and fundamental mechanisms for various combustion and combustion related phenomena in gaseous combustible mixture. It provides the reader with basic knowledge of burning processes and mechanisms of reaction wave propagation. The combustion of a gas mixture (flame, explosion, detonation) is necessarily accompanied by motion of the gas. The process of combustion is therefore not only a chemical phenomenon but also one of gas dynamics. The material selection focuses on the gas phase and

  7. Reduced NOX combustion method

    International Nuclear Information System (INIS)

    Delano, M.A.

    1991-01-01

    This patent describes a method for combusting fuel and oxidant to achieve reduced formation of nitrogen oxides. It comprises: It comprises: heating a combustion zone to a temperature at least equal to 1500 degrees F.; injecting into the heated combustion zone a stream of oxidant at a velocity within the range of from 200 to 1070 feet per second; injecting into the combustion zone, spaced from the oxidant stream, a fuel stream at a velocity such that the ratio of oxidant stream velocity to fuel stream velocity does not exceed 20; aspirating combustion gases into the oxidant stream and thereafter intermixing the aspirated oxidant stream and fuel stream to form a combustible mixture; combusting the combustible mixture to produce combustion gases for the aspiration; and maintaining the fuel stream substantially free from contact with oxidant prior to the intermixture with aspirated oxidant

  8. Materials Control in the Fabrication of Enriched Uranium Fuels; Controle des Matieres au Cours de la Fabrication des Combustibles a Base d'Uranium Enrichi; Uchet materialov pri izgotovlenii topliva na obogashchennom urane; Control de Materiales en la Elaboracion de Combustibles de Uranio Enriquecido

    Energy Technology Data Exchange (ETDEWEB)

    Cardwell, Jr., R. G. [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1966-02-15

    measurement were successfully used where alloy fuel content was critical. Scrap handling had an important effect on the materials balance, by which fuel content was confirmed and good accountability was assured. Records and handling procedures, including batching and physical marking methods, were formulated in a manner that assisted the fabricator in criticality control. (author) [French] Grace aux efforts intenses qui ont ete accomplis au cours des 15 dernieres annees dans le domaine de la technologie des elements de combustible par le Laboratoire national d'Oak Ridge, il a ete possible d'etablir des methodes rationnelles de fabrication et de controle des combustibles eraichis, qui trouvent une iaige application dans la fabrication industrielle des elements de combustible a l'heure actuelle. Des techniques eprouvees de manipulation du combustible enrichi en alliages, en dispersion et sous forme d'oxyde en vrac ont ete mises au point et appliquees a l'etude et a la' fabrication des prototypes d'elements combustibles utilises pour le demarrage du reacteur d'essai de materiaux, du reacteur a protection constituee par la masse du ra- lentisseur ou reacteur piscine, du reacteur de puissance transportable construit pat V, du reacteur protection en tour, du reacteur expose a la Conference de Geneve, du reacteur a haut flux pour la production de radioisotopes et du reacteur experimental refroidi par un gaz. L'experience acquise est la base du present memoire qui traite essentiellement des problemes de controle des matieres qui se posent au cours de la fabrication de differents types d'elements de combustible a base d'uranium enrichi et montre comment ils ont ete resolus. Les objectifs principaux d'un systeme rationnel de controle des matieres sont les suivants: 1. reduire le plus possible le nombre des postes matiere a controler; 2. etablir des releves distincts pour chacune des phases principales des operations et les coordonner de maniere a pouvoir relever les ecarts avec un

  9. Preparation of combustible material from high sulphur coal by means of pyrolysis: magnetic separation; Obtencion de combustibles limpios a partir de carbones con altos contenidos en azure mediante procesos de pirolisis: separacion magnetica

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-11-01

    Basic studies on coal desulphurization by pyrolysis have been carried out with a series of low rank coals with high total sulphur contents and differences in the distribution of sulphur forms. The evolved sulphur compounds were studied by sulphide selective electrode H{sub 2}S and Fourier transform infrared (FTIR) spectroscopy. The mechanisms affecting the sulphur removal during pyrolysis have been studied by scanning electron microscopy coupled with energy dispersive X-ray (SEM-EDX), X-ray diffraction (XRD) and photoelectronic spectroscopy (XPS). A sample coal of 11 Tm, representative of the Teruel basins was processed at pilot scale in a rotary kiln (coal HR). A series of pyrolysis runs simulating the experimental conditions of the rotary kiln were also carried out in laboratory scale. The magnetic behaviour of the chars from the rotary kiln and from the lab-scale pyrolysis was tested. The efficiency of the desulphurization, including pyrolysis and magnetic separation, was calculated. Chars from rotary kiln were tested by thermogravimetric analysis, air reactivity and carbon efficiency combustion in fluidized bed.

  10. Opportunity's Surroundings on Sol 1818

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends. The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view. The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock. This view is presented as a cylindrical projection with geometric seam correction.

  11. The use of halogen carriers and buffers in the spectrographic determination of boron in carbonaceous materials and their combustion products; Empleo de agentes halogenantes y reguladores en la determinacion espectrografica de Boro en carbones y productos derivados

    Energy Technology Data Exchange (ETDEWEB)

    Rucandio, M I; Martin, M; Roca, M

    1992-07-01

    For the determination of boron in carbonaceous materials (high purity graphite, coals and their processed products, such as ashes and slags from thermoelectric power plants) by atomic emission spectroscopy with direct current are excitation and photographic recording, the behaviour of the analyte in the presence of halide compounds or spectrochemical buffers has been studied. Among the halides, cupric fluoride at a low concentration (2%) becomes very suitable for the graphite analysis, and at a higher concentration (25 %) for coals, being necessary in this case to carry out a dilution of samples with graphite. Strontium carbonate as a spectrochemical buffer allows to analyse satisfactorily coals and their combustion products. (Author) 13 refs.

  12. Bed agglomeration risk related to combustion of cultivated fuels (wheat straw, red canary grass, industrial hemp) in commercial bed materials; Baeddagglomereringsrisk vid foerbraenning av odlade braenslen (hampa, roerflen, halm) i kommersiella baeddmaterial

    Energy Technology Data Exchange (ETDEWEB)

    Erhardsson, Thomas; Oehman, Marcus; Geyter, Sigrid de; Oehrstroem, Anna

    2006-12-15

    The market of forest products is expanding and thus resulting in more expensive biomass fuels. Therefore research within the combustion industry for alternative fuels is needed, for example cultivated fuels. Combustion and gasification research on these cultivated fuels are limited. The objectives of this work was to increase the general knowledge of silicon rich cultivated fuels by study the agglomeration characteristics for wheat straw, reed canary grass and industrial hemp in combination with commercial bed materials. Controlled fluidized bed agglomeration tests was conducted in a 5 kW, bench-scale, bubbling fluidized bed reactor. The tendencies of agglomeration were determined with the three cultivated fuels in combination with various minerals present in natural sand (quarts, plagioclase and potassium feldspar) and an alternative bed material (olivine). During the experiments bed samples and formed agglomerates were collected for further analyses with a scanning electron microscope (SEM) and with X-ray microanalysis (EDS). Wheat straw had the highest agglomeration tendency of the studied fuels followed by reed canary grass and industrial hemp. No significant layer formation was found around the different bed particles. Instead, the ash forming matter were found as individual ash sticky (partial melted) particles in the bed. The bed material mineralogical composition had no influence of the agglomeration process because of the non layer formation propensities of the used silicon rich fuels.

  13. Preparation and Characterization of Nano-structured Ceramic Powders Synthesized by Emulsion Combustion Method

    International Nuclear Information System (INIS)

    Takatori, Kazumasa; Tani, Takao; Watanabe, Naoyoshi; Kamiya, Nobuo

    1999-01-01

    The emulsion combustion method (ECM), a novel powder production process, was originally developed to synthesize nano-structured metal-oxide powders. Metal ions in the aqueous droplets were rapidly oxidized by the combustion of the surrounding flammable liquid. The ECM achieved a small reaction field and a short reaction period to fabricate the submicron-sized hollow ceramic particles with extremely thin wall and chemically homogeneous ceramic powder. Alumina, zirconia, zirconia-ceria solid solutions and barium titanate were synthesized by the ECM process. Alumina and zirconia powders were characterized to be metastable in crystalline phase and hollow structure. The wall thickness of alumina was about 10 nm. The zirconia-ceria powders were found to be single-phase solid solutions for a wide composition range. These powders were characterized as equiaxed-shape, submicron-sized chemically homogeneous materials. The powder formation mechanism was investigated through the synthesis of barium titanate powder with different metal sources

  14. Combustion Byproducts Recycling Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Ziemkiewicz, Paul; Vandivort, Tamara; Pflughoeft-Hassett, Debra; Chugh, Y Paul; Hower, James

    2008-08-31

    Each year, over 100 million tons of solid byproducts are produced by coal-burning electric utilities in the United States. Annual production of flue gas desulfurization (FGD) byproducts continues to increase as the result of more stringent sulfur emission restrictions. In addition, stricter limits on NOx emissions mandated by the 1990 Clean Air Act have resulted in utility burner/boiler modifications that frequently yield higher carbon concentrations in fly ash, which restricts the use of the ash as a cement replacement. Controlling ammonia in ash is also of concern. If newer, “clean coal” combustion and gasification technologies are adopted, their byproducts may also present a management challenge. The objective of the Combustion Byproducts Recycling Consortium (CBRC) is to develop and demonstrate technologies to address issues related to the recycling of byproducts associated with coal combustion processes. A goal of CBRC is that these technologies, by the year 2010, will lead to an overall ash utilization rate from the current 34% to 50% by such measures as increasing the current rate of FGD byproduct use and increasing in the number of uses considered “allowable” under state regulations. Another issue of interest to the CBRC would be to examine the environmental impact of both byproduct utilization and disposal. No byproduct utilization technology is likely to be adopted by industry unless it is more cost-effective than landfilling. Therefore, it is extremely important that the utility industry provide guidance to the R&D program. Government agencies and privatesector organizations that may be able to utilize these materials in the conduct of their missions should also provide input. The CBRC will serve as an effective vehicle for acquiring and maintaining guidance from these diverse organizations so that the proper balance in the R&D program is achieved.

  15. Combustion Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — For more than 30 years The Combustion Research Facility (CRF) has served as a national and international leader in combustion science and technology. The need for a...

  16. Alcohol combustion chemistry

    KAUST Repository

    Sarathy, Mani; Oß wald, Patrick; Hansen, Nils; Kohse-Hö inghaus, Katharina

    2014-01-01

    . While biofuel production and its use (especially ethanol and biodiesel) in internal combustion engines have been the focus of several recent reviews, a dedicated overview and summary of research on alcohol combustion chemistry is still lacking. Besides

  17. Infrastructure of the hydrogen use and materials for fuel cells: key for its soon use; Infraestructura de uso de hidrogeno y materiales para celdas de combustible: clave para su pronto uso

    Energy Technology Data Exchange (ETDEWEB)

    Cano Castillo, Ulises; Rejon Garcia, Leonardo; Ojeda Hernandez, Mirna [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2000-07-01

    Nowadays, many products for the personal generation of electrical energy exist, such as the batteries and the of internal combustion machines; that have developed and established the infrastructure required for their manufacture, distribution and commercial use. Nevertheless, disadvantages as well as practical limitations and their relationship with the environment exist. The fuel cells are able to increase their applications, as well as to solve practical and environmental challenges, but still they face challenges related to the initial cost and the infrastructure required for their uses. In this article the materials and the fuel cells (PEM) are described (membrane cells of proton interchange or of polymeric membrane electrolyte), of the proton interchanging membrane, gas diffuser, current collector plates of with fields gas flow fields and electrocatalizers. A table of fuel cells applications is shown according to the type of cell from a power of less than 1 KW to greater than 1 MW. Also there is a table of hydrogen production methods and tables where it is represented the hydrogen route in a PEM cell and the basic components of a type PEM fuel cell. In the article appears a table where a comparison of some properties of current collector plates is shown, as well as a graph of the spectra of electrochemical impedances. [Spanish] Hoy en dia, existen muchos productos para la generacion personal de energia electrica, como las baterias y las maquinas de combustion interna; que han desarrollado y establecido la infraestructura requerida para su fabricacion, distribucion y su uso comercial. Sin embargo, existen desventajas en cuanto a limitaciones practicas y su relacion con el ambiente. Las celdas de combustion son capaces de aumentar sus aplicaciones, asi como resolver retos practicos y ambientales, pero asi enfrentan retos relacionados con el costo inicial y las infraestructura requerida para su usos. En este articulo se describen los materiales y la descripcion

  18. Alternate fuels; Combustibles alternos

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes R, Hernando; Ambriz G, Juan Jose [Universidad Autonoma Metropolitana. Iztapalapa (Mexico)

    2003-07-01

    In the definition and description of alternate fuels we must center ourselves in those technological alternatives that allow to obtain compounds that differ from the traditional ones, in their forms to be obtained. In this article it is tried to give an overview of alternate fuels to the conventional derivatives of petroleum and that allow to have a clear idea on the tendencies of modern investigation and the technological developments that can be implemented in the short term. It is not pretended to include all the tendencies and developments of the present world, but those that can hit in a relatively short term, in accordance with agreed with the average life of conventional fuels. Nevertheless, most of the conversion principles are applicable to the spectrum of carbonaceous or cellulosic materials which are in nature, are cultivated or wastes of organic origin. Thus one will approach them in a successive way, the physical, chemical and biological conversions that can take place in a production process of an alternate fuel or the same direct use of the fuel such as burning the sweepings derived from the forests. [Spanish] En la definicion y descripcion de combustibles alternos nos debemos centrar en aquellas alternativas tecnologicas que permitan obtener compuestos que difieren de los tradicionales, al menos en sus formas de ser obtenidos. En este articulo se pretende dar un panorama de los combustibles alternos a los convencionales derivados del petroleo y que permita tener una idea clara sobre las tendencias de la investigacion moderna y los desarrollos tecnologicos que puedan ser implementados en el corto plazo. No se pretende abarcar todas las tendencias y desarrollos del mundo actual, sino aquellas que pueden impactar en un plazo relativamente corto, acordes con la vida media de los combustibles convencionales. Sin embargo, la mayor parte de los principios de conversion son aplicables al espectro de materiales carbonaceos o celulosicos los cuales se

  19. Interactive wood combustion for botanical tree models

    KAUST Repository

    Pirk, Sören

    2017-11-22

    We present a novel method for the combustion of botanical tree models. Tree models are represented as connected particles for the branching structure and a polygonal surface mesh for the combustion. Each particle stores biological and physical attributes that drive the kinetic behavior of a plant and the exothermic reaction of the combustion. Coupled with realistic physics for rods, the particles enable dynamic branch motions. We model material properties, such as moisture and charring behavior, and associate them with individual particles. The combustion is efficiently processed in the surface domain of the tree model on a polygonal mesh. A user can dynamically interact with the model by initiating fires and by inducing stress on branches. The flames realistically propagate through the tree model by consuming the available resources. Our method runs at interactive rates and supports multiple tree instances in parallel. We demonstrate the effectiveness of our approach through numerous examples and evaluate its plausibility against the combustion of real wood samples.

  20. Maximal combustion temperature estimation

    International Nuclear Information System (INIS)

    Golodova, E; Shchepakina, E

    2006-01-01

    This work is concerned with the phenomenon of delayed loss of stability and the estimation of the maximal temperature of safe combustion. Using the qualitative theory of singular perturbations and canard techniques we determine the maximal temperature on the trajectories located in the transition region between the slow combustion regime and the explosive one. This approach is used to estimate the maximal temperature of safe combustion in multi-phase combustion models

  1. Opportunity's Surroundings on Sol 1687

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 360-degree view of the rover's surroundings on the 1,687th Martian day, or sol, of its surface mission (Oct. 22, 2008). Opportunity had driven 133 meters (436 feet) that sol, crossing sand ripples up to about 10 centimeters (4 inches) tall. The tracks visible in the foreground are in the east-northeast direction. Opportunity's position on Sol 1687 was about 300 meters southwest of Victoria Crater. The rover was beginning a long trek toward a much larger crater, Endeavour, about 12 kilometers (7 miles) to the southeast. This view is presented as a cylindrical projection with geometric seam correction.

  2. Opportunity's Surroundings on Sol 1798

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top. The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock. This view is presented as a cylindrical projection with geometric seam correction.

  3. Starting procedure for internal combustion vessels

    Science.gov (United States)

    Harris, Harry A.

    1978-09-26

    A vertical vessel, having a low bed of broken material, having included combustible material, is initially ignited by a plurality of ignitors spaced over the surface of the bed, by adding fresh, broken material onto the bed to buildup the bed to its operating depth and then passing a combustible mixture of gas upwardly through the material, at a rate to prevent back-firing of the gas, while air and recycled gas is passed through the bed to thereby heat the material and commence the desired laterally uniform combustion in the bed. The procedure permits precise control of the air and gaseous fuel mixtures and material rates, and permits the use of the process equipment designed for continuous operation of the vessel.

  4. Investigations on the emission of air pollutants from small-scale firing plants during the combustion of cereals, straw and similar plant materials; Untersuchungen zur Emission von Luftschadstoffen aus Kleinfeuerungsanlagen bei der Verbrennung von Getreide, Stroh und aehnlichen pflanzlichen Stoffen

    Energy Technology Data Exchange (ETDEWEB)

    Kalkoff, Wolf-Dieter; Maiwald, Birk; Wolf, Stephan

    2013-05-15

    The purpose of the present field study by the State Environmental Protection Office and the State Institution for Agriculture, Forestry and Horticulture of Saxony Anhalt was to measure emissions of relevant pollutants during the combustion of biogenic fuels such as cereals, straw and similar plant materials in exemplary firing installations. In spite of considerable development efforts on the part of manufacturers there are still problems to be solved with some fuels in meeting the tightened limit values of the First Emission Control Ordinance while ensuring user-friendly equipment operability. Based on these insights, as well as the experiences gained in the course of the trial programme, the recommendation for problem fuels such as straw and similar materials is to operate the boiler at full load and provide robust, amply dimensioned ash removal equipment.

  5. Uncertainties in hydrogen combustion

    International Nuclear Information System (INIS)

    Stamps, D.W.; Wong, C.C.; Nelson, L.S.

    1988-01-01

    Three important areas of hydrogen combustion with uncertainties are identified: high-temperature combustion, flame acceleration and deflagration-to-detonation transition, and aerosol resuspension during hydrogen combustion. The uncertainties associated with high-temperature combustion may affect at least three different accident scenarios: the in-cavity oxidation of combustible gases produced by core-concrete interactions, the direct containment heating hydrogen problem, and the possibility of local detonations. How these uncertainties may affect the sequence of various accident scenarios is discussed and recommendations are made to reduce these uncertainties. 40 references

  6. Processing of hydroxyapatite obtained by combustion synthesis

    International Nuclear Information System (INIS)

    Canillas, M.; Rivero, R.; García-Carrodeguas, R.; Barba, F.; Rodríguez, M.A.

    2017-01-01

    One of the reasons of implants failure are the stress forces appearing in the material–tissue interface due to the differences between their mechanical properties. For this reason, similar mechanical properties to the surrounding tissue are desirable. The synthesis of hydroxyapatite by solution combustion method and its processing have been studied in order to obtain fully dense ceramic bodies with improved mechanical strength. Combustion synthesis provides nanostructured powders characterized by a high surface area to facilitate the following sintering. Moreover, synthesis was conducted in aqueous and oxidizing media. Oxidizing media improve homogenization and increase the energy released during combustion. It gives rise to particles whose morphology and size suggest lower surface energies compared with aqueous media. The obtained powders were sintered by using a controlled sintering rate schedule. Lower surfaces energies minimize the shrinkage during sintering and relative densities measurements and diametral compression test confirm improved densification and consequently mechanical properties. [es

  7. Processing of hydroxyapatite obtained by combustion synthesis

    Directory of Open Access Journals (Sweden)

    M. Canillas

    2017-09-01

    Full Text Available One of the reasons of implants failure are the stress forces appearing in the material–tissue interface due to the differences between their mechanical properties. For this reason, similar mechanical properties to the surrounding tissue are desirable. The synthesis of hydroxyapatite by solution combustion method and its processing have been studied in order to obtain fully dense ceramic bodies with improved mechanical strength. Combustion synthesis provides nanostructured powders characterized by a high surface area to facilitate the following sintering. Moreover, synthesis was conducted in aqueous and oxidizing media. Oxidizing media improve homogenization and increase the energy released during combustion. It gives rise to particles whose morphology and size suggest lower surface energies compared with aqueous media. The obtained powders were sintered by using a controlled sintering rate schedule. Lower surfaces energies minimize the shrinkage during sintering and relative densities measurements and diametral compression test confirm improved densification and consequently mechanical properties.

  8. Radioactivity of combustion residues from coal-fired power stations

    International Nuclear Information System (INIS)

    Vom Berg, W.; Puch, K.H.

    1996-01-01

    Each year in Germany, about 18 mill. t of combustion residues are produced from the combustion of bituminous coal and lignite. They are utilized to a great extent in the construction industry and in mining. During the combustion of coal, the radio-nuclides remain predominantly in the ash. The radionuclide concentration in lignite ash is within the range of that in natural soil. The combustion residues of bituminous coal contain radio-nuclides of a similar order of magnitude as also can occur in natural rock. The utilization of combustion residues in construction materials makes a negligible contribution to radiation exposure through retention in buildings. (orig.) [de

  9. Binaural Rendering in MPEG Surround

    Directory of Open Access Journals (Sweden)

    Kristofer Kjörling

    2008-04-01

    Full Text Available This paper describes novel methods for evoking a multichannel audio experience over stereo headphones. In contrast to the conventional convolution-based approach where, for example, five input channels are filtered using ten head-related transfer functions, the current approach is based on a parametric representation of the multichannel signal, along with either a parametric representation of the head-related transfer functions or a reduced set of head-related transfer functions. An audio scene with multiple virtual sound sources is represented by a mono or a stereo downmix signal of all sound source signals, accompanied by certain statistical (spatial properties. These statistical properties of the sound sources are either combined with statistical properties of head-related transfer functions to estimate “binaural parameters” that represent the perceptually relevant aspects of the auditory scene or used to create a limited set of combined head-related transfer functions that can be applied directly on the downmix signal. Subsequently, a binaural rendering stage reinstates the statistical properties of the sound sources by applying the estimated binaural parameters or the reduced set of combined head-related transfer functions directly on the downmix. If combined with parametric multichannel audio coders such as MPEG Surround, the proposed methods are advantageous over conventional methods in terms of perceived quality and computational complexity.

  10. Annual Report: Advanced Combustion (30 September 2012)

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, Jeffrey [NETL; Richards, George

    2012-09-30

    The Advanced Combustion Project addresses fundamental issues of fire-side and steam-side corrosion and materials performance in oxy-fuel combustion environments and provides an integrated approach into understanding the environmental and mechanical behavior such that environmental degradation can be ameliorated and long-term microstructural stability, and thus, mechanical performance can lead to longer lasting components and extended power plant life. The technical tasks of this effort are Oxy-combustion Environment Characterization, Alloy Modeling and Life Prediction, and Alloy Manufacturing and Process Development.

  11. New class of combustion processes

    International Nuclear Information System (INIS)

    Merzhanov, A.G.; Borovinskaya, I.P.

    1975-01-01

    A short review is given of the results of work carried out since 1967 on studying the combustion processes caused by the interaction of chemical elements in the condensed phase and leading to the formation of refractory compounds. New phenomena and processes are described which are revealed when investigating the combustion of the systems of this class, viz solid-phase combustion, fast combustion in the condensed phase, filtering combustion, combustion in liquid nitrogen, spinning combustion, self-oscillating combustion, and repeated combustion. A new direction in employment of combustion processes is discussed, viz. a self-propagating high-temperature synthesis of refractory nitrides, carbides, borides, silicides and other compounds

  12. Multi-stage combustion using nitrogen-enriched air

    Science.gov (United States)

    Fischer, Larry E.; Anderson, Brian L.

    2004-09-14

    Multi-stage combustion technology combined with nitrogen-enriched air technology for controlling the combustion temperature and products to extend the maintenance and lifetime cycles of materials in contact with combustion products and to reduce pollutants while maintaining relatively high combustion and thermal cycle efficiencies. The first stage of combustion operates fuel rich where most of the heat of combustion is released by burning it with nitrogen-enriched air. Part of the energy in the combustion gases is used to perform work or to provide heat. The cooled combustion gases are reheated by additional stages of combustion until the last stage is at or near stoichiometric conditions. Additional energy is extracted from each stage to result in relatively high thermal cycle efficiency. The air is enriched with nitrogen using air separation technologies such as diffusion, permeable membrane, absorption, and cryogenics. The combustion method is applicable to many types of combustion equipment, including: boilers, burners, turbines, internal combustion engines, and many types of fuel including hydrogen and carbon-based fuels including methane and coal.

  13. Combustion modeling in internal combustion engines

    Science.gov (United States)

    Zeleznik, F. J.

    1976-01-01

    The fundamental assumptions of the Blizard and Keck combustion model for internal combustion engines are examined and a generalization of that model is derived. The most significant feature of the model is that it permits the occurrence of unburned hydrocarbons in the thermodynamic-kinetic modeling of exhaust gases. The general formulas are evaluated in two specific cases that are likely to be significant in the applications of the model.

  14. Boiler using combustible fluid

    Science.gov (United States)

    Baumgartner, H.; Meier, J.G.

    1974-07-03

    A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

  15. Contribution to the study of nuclear fuel materials with a metallic uranium base; Contribution a l'etude des materiaux combustibles nucleaires a base d'uranium metallique

    Energy Technology Data Exchange (ETDEWEB)

    Englander, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-11-15

    In a power reactor destined to supply industrially recoverable thermal energy, the most economical source of heat still consists of natural metallic uranium. However, the nuclear fuel material, most often employed in the form of rods of 20 to 40 mm diameter, is subjected to a series of stresses which lead to irreversible distortions usually incompatible with the substructure of the reactor. As a result the fuel material must possess at the outset a certain number of qualities which must be determined. Investigations have therefore been carried out, first on the technological characters peculiar to each of the three allotropic phases of pure uranium metal, and on their interactions on the stabilisation of the material which consists of either cast uranium or uranium pile-treated in the {gamma} phase. (author) [French] Dans un reacteur de puissance destine a fournir de l'energie thermique industriellement recuperable, la source de chaleur la plus economique reste constituee par de l'uranium metallique naturel. Or, le materiau combustible nucleaire, employe le plus souvent sous forme de barreaux de 20 a 40 mm de diametre, se trouve soumis a un ensemble de contraintes qui provoque des deformations irreversibles, le plus souvent incompatibles avec l'infrastructure du reacteur. Par consequent, le materiau combustible doit presenter a l'origine un certain nombre de qualites qu'il est necessaire de determiner. Aussi a-t-on d'abord etudie les caracteres technologiques propres a chacune des trois phases allotropiques de l'uranium-metal pur et leurs interactions sur la stabilisation du materiau constitue soit par de l'uranium coule, soit par de l'uranium traite en pile en phase {gamma}. (auteur)

  16. Lump wood combustion process

    Science.gov (United States)

    Kubesa, Petr; Horák, Jiří; Branc, Michal; Krpec, Kamil; Hopan, František; Koloničný, Jan; Ochodek, Tadeáš; Drastichová, Vendula; Martiník, Lubomír; Malcho, Milan

    2014-08-01

    The article deals with the combustion process for lump wood in low-power fireplaces (units to dozens of kW). Such a combustion process is cyclical in its nature, and what combustion facility users are most interested in is the frequency, at which fuel needs to be stoked to the fireplace. The paper defines the basic terms such as burnout curve and burning rate curve, which are closely related to the stocking frequency. The fuel burning rate is directly dependent on the immediate thermal power of the fireplace. This is also related to the temperature achieved in the fireplace, magnitude of flue gas losses and the ability to generate conditions favouring the full burnout of the fuel's combustible component, which, at once ensures the minimum production of combustible pollutants. Another part of the paper describes experiments conducted in traditional fireplaces with a grate, at which well-dried lump wood was combusted.

  17. The Heat of Combustion of Tobacco and Carbon Oxide Formation

    Directory of Open Access Journals (Sweden)

    Norman AB

    2014-12-01

    Full Text Available Recent studies demonstrated a relationship between mass burn rates of straight-grade cigarettes and heats of combustion of the tobacco materials. In the present work, relationships between measured heats of combustion and elemental composition of the tobacco materials were further analyzed. Heats of combustion measured in oxygen were directly correlated with the carbon and hydrogen content of the tobacco materials tested. Ash content of the materials was inversely related to the heats of combustion. The water insoluble residues from exhaustively extracted tobacco materials showed higher heats of combustion and higher carbon content than the non-extracted materials, confirming a direct relationship between carbon content and heat of combustion. A value for the heat of formation of tobacco was estimated (1175 cal/g from the heat of combustion data and elemental analysis results. The estimated value for heat of formation of tobacco appears to be constant regardless of the material type. Heat values measured in air were uniformly lower than the combustion heats in oxygen, suggesting formation of CO and other reaction products. Gases produced during bomb calorimetry experiments with five tobacco materials were analyzed for CO and CO2 content. When the materials were burned in oxygen, no CO was found in the gases produced. Measured heats of combustion matched estimates based on CO2 found in the gas and conversion of the sample hydrogen content to water. Materials burned in air produced CO2 (56% to 77% of the sample carbon content and appreciable amounts of CO (7% to 16% of the sample carbon content. Unburned residue containing carbon and hydrogen was found in the air combustion experiments. Estimated heat values based on amounts of CO and CO2 found in the gas and water formed from the hydrogen lost during combustion in air were higher than the measured values. These observations indicate formation of products containing hydrogen when the materials

  18. Thermogravimetric analysis of biowastes during combustion

    International Nuclear Information System (INIS)

    Otero, M.; Sanchez, M.E.; Gomez, X.; Moran, A.

    2010-01-01

    The combustion of sewage sludge (SS), animal manure (AM) and the organic fraction of municipal solid waste (OFMSW) was assessed and compared with that of a semianthracite coal (SC) and of a PET waste by thermogravimetric (TG) analysis. Differences were found in the TG curves obtained for the combustion of these materials accordingly to their respective proximate analysis. Non-isothermal thermogravimetric data were used to assess the kinetics of the combustion of these biowastes. The present paper reports on the application of the Vyazovkin model-free isoconversional method for the evaluation of the activation energy necessary for the combustion of these biowastes. The activation energy related to SS combustion (129.1 kJ/mol) was similar to that corresponding to AM (132.5 kJ/mol) while the OFMSW showed a higher value (159.3 kJ/mol). These values are quite higher than the one determined in the same way for the combustion of SC (49.2 kJ/mol) but lower than that for the combustion of a PET waste (165.6 kJ/mol).

  19. Modeling Secondary Organic Aerosol Formation From Emissions of Combustion Sources

    Science.gov (United States)

    Jathar, Shantanu Hemant

    Atmospheric aerosols exert a large influence on the Earth's climate and cause adverse public health effects, reduced visibility and material degradation. Secondary organic aerosol (SOA), defined as the aerosol mass arising from the oxidation products of gas-phase organic species, accounts for a significant fraction of the submicron atmospheric aerosol mass. Yet, there are large uncertainties surrounding the sources, atmospheric evolution and properties of SOA. This thesis combines laboratory experiments, extensive data analysis and global modeling to investigate the contribution of semi-volatile and intermediate volatility organic compounds (SVOC and IVOC) from combustion sources to SOA formation. The goals are to quantify the contribution of these emissions to ambient PM and to evaluate and improve models to simulate its formation. To create a database for model development and evaluation, a series of smog chamber experiments were conducted on evaporated fuel, which served as surrogates for real-world combustion emissions. Diesel formed the most SOA followed by conventional jet fuel / jet fuel derived from natural gas, gasoline and jet fuel derived from coal. The variability in SOA formation from actual combustion emissions can be partially explained by the composition of the fuel. Several models were developed and tested along with existing models using SOA data from smog chamber experiments conducted using evaporated fuel (this work, gasoline, fischertropschs, jet fuel, diesels) and published data on dilute combustion emissions (aircraft, on- and off-road gasoline, on- and off-road diesel, wood burning, biomass burning). For all of the SOA data, existing models under-predicted SOA formation if SVOC/IVOC were not included. For the evaporated fuel experiments, when SVOC/IVOC were included predictions using the existing SOA model were brought to within a factor of two of measurements with minor adjustments to model parameterizations. Further, a volatility

  20. Flameless Combustion Workshop

    National Research Council Canada - National Science Library

    Gutmark, Ephraim

    2005-01-01

    .... "Flameless Combustion" is characterized by high stability levels with virtually no thermoacoustic instabilities, very low lean stability limits and therefore extremely low NOx production, efficient...

  1. Combustion Byproducts Recycling Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower

    2008-08-31

    Ashlines: To promote and support the commercially viable and environmentally sound recycling of coal combustion byproducts for productive uses through scientific research, development, and field testing.

  2. COMBUSTION PROPERTIES OF EUCALYPTUS WOOD

    Directory of Open Access Journals (Sweden)

    Yalçın ÖRS

    1999-03-01

    Full Text Available In this study, the combustion properties of some impregnation materials (abiotic and biotic factors used for eucalyptus wood in interior or exterior environments were investigated. The experimental samples were prepared from Eucalyptus wood based on ASTM-D-1413-76 Tanalith-CBC, boric acid, borax, vacsol-WR, immersol-WR, polyethylen glycole-400 and ammonium sulphate were used as an impregnation material. The results indicated that, vacuum treatment on Eucalyptus gave the lowest retention value of salts. Compounds containing boron+salt increased fire resistance however water repellents decreased the wood flammability.

  3. Combustion Stratification for Naphtha from CI Combustion to PPC

    KAUST Repository

    Vallinayagam, R.; Vedharaj, S.; An, Yanzhao; Dawood, Alaaeldin; Izadi Najafabadi, Mohammad; Somers, Bart; Johansson, Bengt

    2017-01-01

    This study demonstrates the combustion stratification from conventional compression ignition (CI) combustion to partially premixed combustion (PPC). Experiments are performed in an optical CI engine at a speed of 1200 rpm for diesel and naphtha (RON

  4. Nanocrystalline LiMn2O4 derived by HMTA-assisted solution combustion synthesis as a lithium-intercalating cathode material

    International Nuclear Information System (INIS)

    Fey, G.T.-K.; Cho, Y.-D.; Kumar, T. Prem

    2006-01-01

    Nanocrystalline LiMn 2 O 4 was synthesized by a self-sustaining solution combustion method with hexamethylenetetramine as a fuel. Ammonium nitrate was used as an additional oxidant-and-porogen. Thermal analytical studies showed the formation of LiMn 2 O 4 by a single-step decomposition process between 300 and 380 deg. C. The products were highly crystalline with an average crystallite size of ∼30 nm. Charge-discharge studies showed that the optimal heat treatment protocol was a 10 h calcination at 700 deg. C. A product obtained under these conditions from a precursor containing a 1:1 molar ratio of [LiNO 3 + Mn(NO 3 ) 2 ] and NH 4 NO 3 sustained 202 cycles between 3.0 and 4.3 V at a charge-discharge rate of 0.1 C before reaching an 80% charge retention cut-off value. Nanocrystalline particles provide small diffusion pathways that lead to an improvement in the lithium-ion intercalation kinetics and minimize surface distortions during cycling. These factors are believed to confer excellent electrochemical properties to the product

  5. Strobes: An oscillatory combustion

    NARCIS (Netherlands)

    Corbel, J.M.L.; Lingen, J.N.J. van; Zevenbergen, J.F.; Gijzeman, O.L.J.; Meijerink, A.

    2012-01-01

    Strobe compositions belong to the class of solid combustions. They are mixtures of powdered ingredients. When ignited, the combustion front evolves in an oscillatory fashion, and flashes of light are produced by intermittence. They have fascinated many scientists since their discovery at the

  6. Catalytically enhanced combustion process

    International Nuclear Information System (INIS)

    Rodriguez, C.

    1992-01-01

    This patent describes a fuel having improved combustion efficiency. It comprises a petroleum based liquid hydrocarbon; and a combustion catalyst comprising from about 18 to about 21 weight percent naphthalene, from about 75 to about 80 weight percent toluene, and from about 2.8 to about 3.2 weight percent benzyl alcohol

  7. Fifteenth combustion research conference

    International Nuclear Information System (INIS)

    1993-01-01

    The BES research efforts cover chemical reaction theory, experimental dynamics and spectroscopy, thermodynamics of combustion intermediates, chemical kinetics, reaction mechanisms, combustion diagnostics, and fluid dynamics and chemically reacting flows. 98 papers and abstracts are included. Separate abstracts were prepared for the papers

  8. Fuels and Combustion

    KAUST Repository

    Johansson, Bengt

    2016-08-17

    This chapter discusses the combustion processes and the link to the fuel properties that are suitable for them. It describes the basic three concepts, including spark ignition (SI) and compression ignition (CI), and homogeneous charge compression ignition (HCCI). The fuel used in a CI engine is vastly different from that in an SI engine. In an SI engine, the fuel should sustain high pressure and temperature without autoignition. Apart from the dominating SI and CI engines, it is also possible to operate with a type of combustion: autoignition. With HCCI, the fuel and air are fully premixed before combustion as in the SI engine, but combustion is started by the increased pressure and temperature during the compression stroke. Apart from the three combustion processes, there are also a few combined or intermediate concepts, such as Spark-Assisted Compression Ignition (SACI). Those concepts are discussed in terms of the requirements of fuel properties.

  9. Fuels and Combustion

    KAUST Repository

    Johansson, Bengt

    2016-01-01

    This chapter discusses the combustion processes and the link to the fuel properties that are suitable for them. It describes the basic three concepts, including spark ignition (SI) and compression ignition (CI), and homogeneous charge compression ignition (HCCI). The fuel used in a CI engine is vastly different from that in an SI engine. In an SI engine, the fuel should sustain high pressure and temperature without autoignition. Apart from the dominating SI and CI engines, it is also possible to operate with a type of combustion: autoignition. With HCCI, the fuel and air are fully premixed before combustion as in the SI engine, but combustion is started by the increased pressure and temperature during the compression stroke. Apart from the three combustion processes, there are also a few combined or intermediate concepts, such as Spark-Assisted Compression Ignition (SACI). Those concepts are discussed in terms of the requirements of fuel properties.

  10. PDF Modeling of Turbulent Combustion

    National Research Council Canada - National Science Library

    Pope, Stephen B

    2006-01-01

    .... The PDF approach to turbulent combustion has the advantages of fully representing the turbulent fluctuations of species and temperature, and of allowing realistic combustion chemistry to be implemented...

  11. Effects of combustible stacking in large compartments

    DEFF Research Database (Denmark)

    Gentili, Filippo; Giuliani, Luisa; Bontempi, Franco

    2013-01-01

    This paper focuses on the modelling of fire in case of various distributions of combustible materials in a large compartment. Large compartments often represent a challenge for structural fire safety, because of lack of prescriptive rules to follow and difficulties of taking into account the effect...... of non uniform distribution of the combustible materials and fire propagation. These aspects are discussed in this paper with reference to an industrial steel building, taken as case study. Fires triggered by the burning of wooden pallets stored in the premises have been investigated with respect...

  12. Neutron spectrum in small iron pile surrounded by lead reflector

    International Nuclear Information System (INIS)

    Kimura, Itsuro; Hayashi, S.A.; Kobayashi, Katsuhei; Matsumura, Tetsuo; Nishihara, Hiroshi.

    1978-01-01

    In order to save the quantity of sample material, a possibility to assess group constants of a reactor material through measurement and analysis of neutron spectrum in a small sample pile surrounded by a reflector of heavy moderator, was investigated. As the sample and the reflector, we chose iron and lead, respectively. Although the time dispersion in moderation of neutrons was considerably prolonged by the lead reflector, this hardly interferes with the assessment of group constants. Theoretical calculation revealed that both the neutron flux spectrum and the sensitivity coefficient of group constants in an iron sphere, 35 cm in diameter surrounded by the lead reflector, 25 cm thick, were close to those of the bare iron sphere, 108 cm in diameter. The neutron spectra in a small iron pile surrounded by a lead reflector were experimentally obtained by the time-of-flight method with an electron linear accelerator and the result was compared with the predicted values. It could be confirmed that a small sample pile surrounded by a reflector, such as lead, was as useful as a much larger bulk pile for the assessment of group constants of a reactor material. (auth.)

  13. Placental vascular responses are dependent on surrounding tissue

    DEFF Research Database (Denmark)

    Brøgger, Torbjørn Halle

    . Materials and methods. From fresh born placentas, stem villi arteries were carefully dissected. The artery branches were divided. The surrounding tissue was removed from one end and was left untouched in the other end.Then, using wire myography, they were investigated in terms of contractility...... and sensitivity to physiological relevant human-like agonists. Results. Sensitivity to PGF2α, Tx-analog, 5-HT and endothelin-1 was significantly lower in arteries with intact surrounding tissue compared to arteries stripped of the tissue. The maximal force development was also significantly lower in arteries...... with surrounding tissue when they were depolarized high extracellular [K+] or stimulated with PGF2α or endotheline-1. Conclusion. The perivascular tissue significantly alters stem villi arteries' sensitivity and force development in a suppressive way. This implicates a new aspect of blood flow regulation...

  14. Testing a model-guided approach to the development of new thermoluminescent materials using YAG:Ln produced by solution combustion synthesis

    International Nuclear Information System (INIS)

    Milliken, E.D.; Oliveira, L.C.; Denis, G.; Yukihara, E.G.

    2012-01-01

    The objective of this work is to test a model-guided approach, coupled with an efficient material synthesis method, for the development of new thermoluminescent (TL) material using yttrium aluminum garnet (YAG, Y 3 Al 5 O 12 ) as a model material. We systematically investigated undoped and lanthanide-doped YAG using x-ray diffraction (XRD), TL, and radioluminescence (RL) to understand the role of the lanthanides in the TL process, i.e., whether they act as trapping centers or recombination centers. We also prepared samples with multiple dopants to test the possibility of creating materials with multiple TL peaks. The initial rise method of TL analysis was used to estimate the activation energies associated with the TL peaks. The role of the lanthanide impurities predicted using the lanthanide energy level diagram was largely confirmed, as evidenced by the TL curves, TL emission spectra and activation energy analysis. However, our data suggests that the exact role of the lanthanide dopants during the TL process depends on the thermal stability of the trapped charges, i.e. the same lanthanide can act as a trapping center in one system and as a recombination center in another system. These results demonstrate the possibility of introducing appropriate TL peaks and recombination centers in YAG produced by SCS by lanthanide doping, where the role of the lanthanide dopant is consistent with a model for the lanthanide energy levels. This allows for a more guided approach to the development of new TL materials with peaks in certain temperature range or multiple TL peaks, at least in conditions in which the model applies. - Highlights: ► TL peaks and recombination centers introduced in YAG by Ln doping. ► Role of the Ln consistent with model for the Ln energy levels. ► Model-guided approach to the development of new TL materials demonstrated.

  15. Fuel Combustion Laboratory | Transportation Research | NREL

    Science.gov (United States)

    Fuel Combustion Laboratory Fuel Combustion Laboratory NREL's Fuel Combustion Laboratory focuses on designs, using both today's technology and future advanced combustion concepts. This lab supports the combustion chamber platform for fuel ignition kinetics research, was acquired to expand the lab's

  16. Fluidized bed combustion: mixing and pollutant limitation

    Energy Technology Data Exchange (ETDEWEB)

    Leckner, B. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Energy Conversion

    1997-10-01

    Fluidized bed combustion (FBC) has been applied commercially during a few decades, and sufficient knowledge is gained to design boilers with sizes of up to several hundreds of megawatt thermal power (MW{sub th}). The knowledge of what goes on inside a large combustion chamber is still limited, however, and this impedes further optimization and efficient solution of problems that might occur. Despite this lack of knowledge the present survey deals with combustion chamber processes and discusses mixing and distribution of fuel and air in the combustion chamber and its importance for sulphur capture and reduction of emissions of nitrogen oxides. It is desirable to present the material in a general way and to cover the entire field of FBC. However, the scarce openly published information deals mostly with coal combustion in atmospheric circulating fluidized bed (CFB) combustors, and therefore this application will receive most attention, but reference is also made to pressurized combustion and to other fuels than coal. In this context the important work made in the LIEKKI project on the analysis of different fuels and on the influence of pressure should be especially pointed out. (orig.)

  17. Utilization of coal ash from fluidized-bed combustion boilers as road base material; Sekitandaki ryudoso boiler kara no sekitanbai no robanzai to shite no riyo

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, Y. [Kawasaki Heavy Industries, Ltd., Kobe (Japan); Kozasa, K. [Center for Coal Utilization, Japan, Tokyo (Japan); Tsuzura, K. [Naruto Salt Mfg. Co. Ltd., Tokushima (Japan); Izumi, H. [Nippon Hodo Co. Ltd., Tokyo (Japan)

    1998-03-01

    Coal ash from the fluidized bed boiler is evaluated for its properties as is, as solidified or granulated, and as the roadbed material. The coal ash tested in the experiment is a mixture of ash from the fluidized bed boiler bottom, ash from the cyclone separator, and ash from the bag filter. In the manufacture of solid or granulated bodies, coal ashes are kneaded in water whose amount puts the mixture near the plasticization limit, are pressed in a low-pressure press and made into solid bodies by a 15-hour curing in 60degC saturated steam, and the solid bodies are crushed into solid granules. A content release test is conducted about the release of dangerous substances, and road paving experiments are conducted to learn the workability and serviceability of the granulated material as a road paving material. A study of the experimental results discloses what is mentioned below. Coal ash containing 10-20vol% of CaO and 15vol% or less of unburnt carbon turns into a high-strength solid after curing in saturated steam whose temperature is not higher than 60degC. The granulated solid satisfies the standards that an upper subbase material is expected to satisfy. It also meets the environmental standards in a release content test for soil set forth by Environment Agency notification No.46. 8 refs., 8 figs., 4 tabs.

  18. COMBUSTION OF BIOMASS AND CHARCOAL MADE FROM BABASSU NUTSHELL

    Directory of Open Access Journals (Sweden)

    Thiago de Paula Protásio

    2017-03-01

    Full Text Available In recent years, studies have examined the use of lignocellulosic wastes for energy generation. However, there is a lack of information on the combustibility of the residual biomass, especially the bark and charcoal of babassu nut. In this study, thermogravimetric analysis (TGA, differential thermal analysis (DTA and differential scanning calorimetry (DSC were used to achieve the following objectives: to evaluate the combustion of the residual biomass from the babassu nut; to evaluate the combustion of charcoal produced from this biomass, considering different final carbonization temperatures; and to determine the effect of the final carbonization temperature on the thermal stability of charcoal and on its performance in combustion. Thermal analyses were performed in synthetic air. In order to evaluate the characteristics of charcoal combustion and fresh biomass, the ignition temperature (Ti, the burnout temperature (Tf, characteristic combustion index (S, ignition index (Di, time corresponding to the maximum combustion rate (tp, and ignition time (tig were considered. The combustion of the babassu nutshell occurred in three phases and it was observed that this lignocellulosic material is suitable for the direct generation of heat. The increase in the final carbonization temperature caused an increase in the ignition temperature, as well as in the burnout temperature, the ignition time and the time corresponding to the maximum combustion rate. The results indicate that the increase in the carbonization temperature causes a decrease in combustion reactivity and, consequently, the charcoals produced at lower temperatures are easier to ignite and exhibit better performance in ignition.

  19. Sandia Combustion Research: Technical review

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    This report contains reports from research programs conducted at the Sandia Combustion Research Facility. Research is presented under the following topics: laser based diagnostics; combustion chemistry; reacting flow; combustion in engines and commercial burners; coal combustion; and industrial processing. Individual projects were processed separately for entry onto the DOE databases.

  20. Recycling of LiCo0.59Mn0.26Ni0.15O2 cathodic material from spent Li-ion batteries by the method of the citrate gel combustion

    Directory of Open Access Journals (Sweden)

    Senćanski Jelena V.

    2017-01-01

    Full Text Available The Li-ion batteries are the main power source for the high technology devices, such as mobile phones and electric vehicles. Because of that, the number of spent Li-ion batteries significantly increases. Today, the number of active mobile phones crossed 7.19 billion. It is estimated that the mass of the spent lithium ion batteries in China will exceed 500,000 t by 2020. The trouble is in the ingredients of these batteries. They contain Li, Co, Mn, Ni, Cu, Al and toxic and flammable electrolytes which have a harmful affection to the environment. Because of that, the recycling procedure attracts raising attention of researches. Several commercial spent Li-ion batteries were recycled by the relatively fast, economic and simple procedure. The three ways of separating the cathode material from Al collector were examined after the manual dismantling of the components of batteries with the Li(Co–Mn–NiO2 as cathode material. These were: 1. dissolution of the Al collector in the alkali medium, 2. peeling off with N-methylpyrrolidone and 3. thermal decomposition of the adhesive at 700°C. The procedure with the highest yield was the one with the dissolution in alkali medium. The chemical analysis of the single batteries'' components (the crust, Al/Cu collector, cathode material were done by the atomic absorption spectrometry. The components, before the analysis, were dissolved. The re-synthesis of the cathode material by the method of the citrate gel combustion was done after the separating the cathode material and dissolving it in the nitric acid. The obtained product was, after annealing, characterized by the methods of X-ray diffraction and Raman spectroscopy. The recycled product was LiCo0.59Mn0.26Ni0.15O2 stoichiometry, with the hexagonal layered structure α-NaFeO2 type. The functionalization of the resynthesized material was examined in the 1 M solution LiClO4 in the propylene carbonate, by galvanostatic charging, with the current density of 0

  1. Shale oil combustion

    International Nuclear Information System (INIS)

    Al-dabbas, M.A.

    1992-05-01

    A 'coutant' carbon steel combustion chamber cooled by water jacket was conslructed to burn diesel fuel and mixlure of shale oil and diesel fuels. During experimental work nir fuel ratio was determined, temperaturces were measured using Chromel/ Almel thermocouple, finally the gasous combustion product analysis was carricd out using gas chromatograph technique. The constructed combustion chamber was operating salisfactory for several hours of continous work. According to the measurements it was found that: the flame temperature of a mixture of diesel and shale oil fuels was greater than the flame temperature of diesel fuel. and the sulfer emissious of a mixture of diesel and shale oil fuels was higher than that of diesel fuel. Calculation indicated that the dry gas energy loss was very high and the incomplete combustion energy loss very small. (author). 23 refs., 35 figs

  2. Shale oil combustion

    Energy Technology Data Exchange (ETDEWEB)

    Al-dabbas, M A

    1992-05-01

    A `coutant` carbon steel combustion chamber cooled by water jacket was conslructed to burn diesel fuel and mixlure of shale oil and diesel fuels. During experimental work nir fuel ratio was determined, temperaturces were measured using Chromel/ Almel thermocouple, finally the gasous combustion product analysis was carricd out using gas chromatograph technique. The constructed combustion chamber was operating salisfactory for several hours of continous work. According to the measurements it was found that: the flame temperature of a mixture of diesel and shale oil fuels was greater than the flame temperature of diesel fuel. and the sulfer emissious of a mixture of diesel and shale oil fuels was higher than that of diesel fuel. Calculation indicated that the dry gas energy loss was very high and the incomplete combustion energy loss very small. (author). 23 refs., 35 figs.

  3. Indoor combustion and asthma.

    Science.gov (United States)

    Belanger, Kathleen; Triche, Elizabeth W

    2008-08-01

    Indoor combustion produces both gases (eg, nitrogen dioxide, carbon monoxide) and particulate matter that may affect the development or exacerbation of asthma. Sources in the home include both heating devices (eg, fireplaces, woodstoves, kerosene heaters, flued [ie, vented] or nonflued gas heaters) and gas stoves for cooking. This article highlights the recent literature examining associations between exposure to indoor combustion and asthma development and severity. Since asthma is a chronic condition affecting both children and adults, both age groups are included in this article. Overall, there is some evidence of an association between exposure to indoor combustion and asthma, particularly asthma symptoms in children. Some sources of combustion such as coal stoves have been more consistently associated with these outcomes than other sources such as woodstoves.

  4. Caracterização de íons majoritários presentes no material particulado gerado por combustão de motores do ciclo diesel

    OpenAIRE

    Regis, Ana Carla Dias

    2011-01-01

    92 f. Atualmente, tanto a necessidade de melhor compreensão dos mecanismos de formação de partículas atmosféricas quanto os efeitos do MPA no ambiente e na saúde humana, geram uma busca por espécies químicas que possam ser usadas como marcadores de fontes e/ou precursores de material particulado. Dentre estas, encontram-se os íons majoritários (formiato, acetato, oxalato, succinato, F-, Cl-, NO3-, SO42-,PO43-, dentre outros), estes podem ser representantes tanto de poluição atmosférica pri...

  5. Combustion synthesis and preliminary luminescence studies of ...

    Indian Academy of Sciences (India)

    The polycrystalline sample of LiBaPO4 : Tb3+ (LBPT) was successfully synthesized by solution combustion synthesis and studied for its luminescence characteristics. The thermoluminescence (TL) glow curve of LBPT material consists of two peaks at 204.54 and 251.21°C. The optimum concentration was 0.005 mol to ...

  6. Advanced Fuels and Combustion Processes for Propulsion

    Science.gov (United States)

    2010-09-01

    production from biomass steam reforming – Conduct a feasibility analysis of the proposed integrated process Energia Technologies - D. Nguyen & K. Parimi...strength foam material development by Ultramet – Combustion experiments performed U. Of Alabama – End-user input provided by Solar Turbines Major

  7. Religion's relationship with social boundaries surrounding gender ...

    African Journals Online (AJOL)

    Religion's relationship with social boundaries surrounding gender. ... is associated with segregation, marginalization and differentiation between men and women. ... are necessary in the society it should not be mistaken for gender inequality.

  8. Experimental research on combustion fluorine retention using calcium-based sorbents during coal combustion (II)

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Q.; Ma, X.; Liu, J.; Wu, X.; Zhou, J.; Cen, K. [Liaoning Technical University, Fuxin (China). College of Resource and Environment Engineering

    2008-12-15

    Fluoride pollution produced by coal burning can be controlled with the calcium-based sorbent combustion fluorine technique in which calcium-based sorbents are mixed with the coal or sprayed into the combustion chamber. In a fixed bed tube furnace combustion experiment using one calcium-based natural mineral, limestone and one calcium-based building material, it was shown that the calcium-based sorbent particle grain size and pore structure have a big influence on the combustion fluorine retention effect. Reducing the calcium-based sorbent particle grain size and improving the calcium sorbent structure characteristics at very high temperature to enhance the fluorine retention effect is the important approach to the fluorine retention agent development. 8 refs., 1 fig., 5 tabs.

  9. Heavy metals behaviour during mono-combustion and co-combustion of sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, M. Helena; Abelha, Pedro; Olieveira, J.F. Santos; Gulyurtlu, Ibrahim; Cabrita, Isabel [INETI-DEECA, Lisboa (Portugal)

    2005-03-01

    This paper presents the study of the combustion of granular dry sewage sludge performed on a pilot fluidized bed system. The results of mono-combustion of sludge and co-combustion with coal were compared with those of coal combustion for ash partitioning, the formation of gaseous pollutants and heavy metals behaviour. It was found that the mineral matter of sludge was essentially retained as bottom ashes. The production of fines ashes was small during the mono-combustion due to the tendency of coal to produce fine ashes which also contained unburned char. The degree of heavy metal volatilization was found to be slightly higher during co-combustion than in mono-combustion; however, most of them were retained in ashes and their emissions were found to be below the regulated levels. Hg was completely volatilized; however, during combustion trials involving coal it was captured by cyclone ashes at temperatures below 300 deg C. During sludge mono-combustion the retention of Hg in cyclone ashes containing low LOI was not enough to decrease emissions below the regulated levels; hence, it is necessary to install dedicated flue gas treatment for Hg removal. The leachability and ecotoxicity of sludge and ashes was compared with the new regulatory limits for landfill disposal in the EU. It was found that the release of organic matter and heavy metals found in the sludge was low from granular bed ashes; hence, except for sulphate release, bed ashes were converted into inert and non-ecotoxic materials. Ashes from test with limestone and cyclone ashes seemed to be more problematic because of pH effects and contamination with steel corrosion products. The recovery and reutilization of sludge bed ashes could, therefore, be possible, as long as the release of sulphate do not interfere with the process.

  10. Fe Al40, a new canning material for reactors using refractory fuels; Le Fe Al40, un nouveau materiau de gainage pour les reacteurs a combustibles refractaires

    Energy Technology Data Exchange (ETDEWEB)

    Sainfort, G; Cabane, G; Salesse, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    18-10 niobium - stabilized stainless steel, in water, either de oxygenated or saturated with oxygen at 25 C, the weight gain is one hundred time smaller than that of mild steel, after a 3 month test, in water vapour at 500 C, also after 3 months, only the growth of impervious and very adherent oxide skins is observed, in sodium up to 1000 h at 700 C, the behaviour is at least as good as that of stainless steel. No diffusion reaction has been detected either with uranium dioxide up to 800 C, or with uranium carbide up to 700 C. Extension specimens and thin walled cans are subjected to high flux irradiations between 20 and 700 C; preliminary results will be given. (authors) [French] Le Fe Al40, grace a sa haute teneur en aluminium, presente de grands avantages sur les aciers inoxydables, pour les applications nucleaires; en particulier, sa section efficace est moitie de celle de l'acier a 18 p.100 Cr et 10 p.100 Ni, et sa compatibilite avec les elements combustibles et avec les fluides caloporteurs est exceptionnellement bonne. Les alliages ferreux, contenant plus de 16 p.100 en poids d'aluminium, sont reputes fragiles en raison de leur structure ordonnee. En fait, la plus grande partie de la fragilite de ces alliages est due a la presence de precipites intergranulaires. L'emploi de fer et d'aluminium purs, ainsi que des additions destinees a pieger les traces d'impuretes residuelles, permet d'obtenir, par coulee sous vide, un alliage tres propre dont la fragilite a chaud est suffisamment reduite pour permettre une transformation. avec un excellent rendement. Les etudes de fonderie et de transformation, qui ont defini la composition de l'alliage et les meilleures conditions industrielles de preparation, seront decrites. Les proprietes mecaniques des produits files ou lamines sont conditionnees par la structure ferritique ordonnee des alliages ainsi prepares: allongement par traction a temperature ambiante compris entre 8 et 11 p.100, augmentation progressive de l

  11. Particle Emissions from Biomass Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Szpila, Aneta; Bohgard, Mats [Lund Inst. of Technology (Sweden). Div. of Ergonomics and Aerosol Technology; Strand, Michael; Lillieblad, Lena; Sanati, Mehri [Vaexjoe Univ. (Sweden). Div. of Bioenergy Technology; Pagels, Joakim; Rissler, Jenny; Swietlicki, Erik; Gharibi, Arash [Lund Univ. (Sweden). Div. of Nuclear Physics

    2003-05-01

    We have shown that high concentrations of fine particles of the order of 2-7x10{sup -7} particles per cm{sup 3} are being formed in all the combustion units studied. There was a higher difference between the units in terms of particle mass concentrations. While the largest differences was found for gas-phase constituents (CO and THC) and polyaromatic hydrocarbons. In 5 out of 7 studied units, multi-cyclones were the only measure for flue-gas separation. The multicyclones had negligible effect on the particle number concentration and a small effect on the mass of particles smaller than 5 {mu}m. The separation efficiency was much higher for the electrostatic precipitators. The boiler load had a dramatic influence on the coarse mode concentration during combustion of forest residue. PM0.8-6 increased from below 5 mg/m{sup 3} to above 50 mg/m{sup 3} even at a moderate change in boiler load from medium to high. A similar but less pronounced trend was found during combustion of dry wood. PM0.8-PM6 increased from 12 to 23 mg/m{sup 3} when the load was changed from low to high. When increasing the load, the primary airflow taken through the grate is increased; this itself may lead to a higher potential of the air stream to carry coarse particles away from the combustion zone. Measurements with APS-instrument with higher time-resolution showed a corresponding increase in coarse mode number concentration with load. Additional factor influencing observed higher concentration of coarse mode during combustion of forest residues, could be relatively high ash content in this type of fuel (2.2 %) in comparison to dry wood (0.3 %) and pellets (0.5 %). With increasing load we also found a decrease in PM1 during combustion of forest residue. Whether this is caused by scavenging of volatilized material by the high coarse mode concentration or a result of a different amount of volatilized material available for formation of fine particles needs to be shown in future studies. The

  12. Possible combustion hazards in 3013 plutonium waste container

    International Nuclear Information System (INIS)

    Sherman, M.P.

    1999-01-01

    Are there combustion hazards in plutonium-contaminated waste containers caused by combustible gas generation? Current gas generation models in which the only reaction considered is radiolysis must inevitably predict eventual complete dissociation of any water present into hydrogen and oxygen. Waste prepared for the 3013 container should be less subject to this problem because organic material and most of the absorbed water should have been removed. Depending on the waste form, moisture content, organic content, temperature, and container material, the pressure rise due to gas generation will be bounded by backreactions, recombination of the hydrogen and oxygen, absorption of the oxygen by plutonium oxide, and possibly other chemical reactions. Examination of a variety of food pack waste containers at Los Alamos National Laboratory (LANL) has shown little pressure rise, indeed often subatmospheric pressures. In a few cases large hydrogen concentrations up to 47% mole fraction were observed, but with negligible oxygen content. The only fuel seen in significant quantities was H 2 and, in one case, CO; the only oxidizer seen in significant quantities was O 2 . Considerable work on measuring gas generation is being done at Westinghouse Savannah River Company and LANL. In a mixture of H 2 , O 2 , and other diluent gases, if the hydrogen concentration is below the value at the lean flammability limit, or if the oxygen concentration is below that at the rich flammability limit, a flame will not propagate from an ignition source. Assuming H 2 is the only fuel present in significant quantities, a mixture leaner than the lean limit will get only leaner if mixed with air and is therefore no combustion hazard. However, when a mixture containing large amounts of H 2 is nonflammable because there is insufficient O 2 , there is a hazard. If the mixture should leak into a volume containing O 2 , or the container is opened into the surrounding air, the mixture will pass through the

  13. Oxygen isotopic signature of CO2 from combustion processes

    Directory of Open Access Journals (Sweden)

    W. A. Brand

    2011-02-01

    Full Text Available For a comprehensive understanding of the global carbon cycle precise knowledge of all processes is necessary. Stable isotope (13C and 18O abundances provide information for the qualification and the quantification of the diverse source and sink processes. This study focuses on the δ18O signature of CO2 from combustion processes, which are widely present both naturally (wild fires, and human induced (fossil fuel combustion, biomass burning in the carbon cycle. All these combustion processes use atmospheric oxygen, of which the isotopic signature is assumed to be constant with time throughout the whole atmosphere. The combustion is generally presumed to take place at high temperatures, thus minimizing isotopic fractionation. Therefore it is generally supposed that the 18O signature of the produced CO2 is equal to that of the atmospheric oxygen. This study, however, reveals that the situation is much more complicated and that important fractionation effects do occur. From laboratory studies fractionation effects on the order of up to 26%permil; became obvious in the derived CO2 from combustion of different kinds of material, a clear differentiation of about 7‰ was also found in car exhausts which were sampled directly under ambient atmospheric conditions. We investigated a wide range of materials (both different raw materials and similar materials with different inherent 18O signature, sample geometries (e.g. texture and surface-volume ratios and combustion circumstances. We found that the main factor influencing the specific isotopic signatures of the combustion-derived CO2 and of the concomitantly released oxygen-containing side products, is the case-specific rate of combustion. This points firmly into the direction of (diffusive transport of oxygen to the reaction zone as the cause of the isotope fractionation. The original total 18O signature of the material appeared to have little influence, however, a contribution of specific bio

  14. Pilot Demonstration of Technology for the Production of High Value Materials from the Ultra-Fine (PM2.5) Fraction of Coal Combustion Ash

    Energy Technology Data Exchange (ETDEWEB)

    T. L. Robl; J. G. Groppo; R. Rathbone; B. Marrs; R. Jewell

    2008-07-18

    The overall objective of this research was to determine the feasibility of recovering a very fine fraction of fly ash, that is 5 microns in diameter or less and examining the characteristics of these materials in new or at least less traditional applications. These applications included as a polymer filler or as a 'super' pozzolanic concrete additive. As part of the effort the ash from 6 power plants was investigated and characterized. This work included collection from ESP Hoppers and ponds. The ash was thoroughly characterized chemically and physically. Froth flotation was used to reduce the carbon and testing showed that flotation could effectively reduce carbon to acceptable levels (i.e. 0.5% LOI) for most of the substrates tested. in order to enable eventual use as fillers. Hydraulic classification was used in the separation of the fine ash from the coarse ash. Hydraulic classification requires the ash to be dispersed to be effective and a range of dispersants were tested for adsorption as well as sedimentation rate. A wide range of dosages were required (0.3 to 10 g/kg). In general the ponded ash required less dispersant. A model was developed for hydraulic classification. A pilot-scale hydraulic classifier was also designed and operated for the project. Product yields of up to 21% of feed solids were achieved with recoveries of <5 {micro}m particles as high as 64%. Mean particle sizes (D{sub 50}) of the ultra fine ash (UFA) products varied from 3.7 to 10 {micro}m. A patent was filed on the classifier design. A conceptual design of a Process Demonstration Unit (PDU) with a feed rate of 2 tons of raw ash feed per hour was also completed. Pozzolanic activity was determined for the UFA ashes in mortars. In general the overall strength index was excellent with values of 90% achieved in 3 days and {approx}100% in 7 days. Three types of thermoplastic polymers were evaluated with the UFA as a filler: high density polyethylene, thermoplastic elastomer and

  15. Mechanisms and kinetics of granulated sewage sludge combustion.

    Science.gov (United States)

    Kijo-Kleczkowska, Agnieszka; Środa, Katarzyna; Kosowska-Golachowska, Monika; Musiał, Tomasz; Wolski, Krzysztof

    2015-12-01

    This paper investigates sewage sludge disposal methods with particular emphasis on combustion as the priority disposal method. Sewage sludge incineration is an attractive option because it minimizes odour, significantly reduces the volume of the starting material and thermally destroys organic and toxic components of the off pads. Additionally, it is possible that ashes could be used. Currently, as many as 11 plants use sewage sludge as fuel in Poland; thus, this technology must be further developed in Poland while considering the benefits of co-combustion with other fuels. This paper presents the results of experimental studies aimed at determining the mechanisms (defining the fuel combustion region by studying the effects of process parameters, including the size of the fuel sample, temperature in the combustion chamber and air velocity, on combustion) and kinetics (measurement of fuel temperature and mass changes) of fuel combustion in an air stream under different thermal conditions and flow rates. The combustion of the sludge samples during air flow between temperatures of 800 and 900°C is a kinetic-diffusion process. This process determines the sample size, temperature of its environment, and air velocity. The adopted process parameters, the time and ignition temperature of the fuel by volatiles, combustion time of the volatiles, time to reach the maximum temperature of the fuel surface, maximum temperature of the fuel surface, char combustion time, and the total process time, had significant impacts. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Numerical Simulation of the Heat Transfer Behavior of a Zigzag Plate Containing a Phase Change Material for Combustion Heat Recovery and Power Generation

    Directory of Open Access Journals (Sweden)

    Peilun Wang

    2016-01-01

    Full Text Available This study presents a numerical analysis of the melting process of phase change materials (PCMs within a latent heat thermal energy storage (LHTES system employing zigzag plate. The numerical model used NaCl-MgCl2 mixture as PCMs and hot air as heat transfer fluid (HTF. An experimental system was built to validate the model, and the experimental data agrees reasonably well with the simulation results. The simulation results revealed the effects of the Reynolds and Stefan numbers and the surface topography of the zigzag plate on the charging process. Besides, the effect of the relationship between Reynolds and Stefan numbers on the charging process under a new boundary condition employing a fixed input power was studied. It is found that by modifying the shape of the zigzag plate surface it is feasible to enhance the heat transfer of the LHTES unit remarkably. The melting rate of PCMs increases with the value of Ste or Re numbers with only one of them changing; however, the melting rate of PCMs decreases with the increasing Ste (or decreasing Re in a fixed input power condition.

  17. Ecological mechanisms linking protected areas to surrounding lands.

    Science.gov (United States)

    Hansen, Andrew J; DeFries, Ruth

    2007-06-01

    Land use is expanding and intensifying in the unprotected lands surrounding many of the world's protected areas. The influence of this land use change on ecological processes is poorly understood. The goal of this paper is to draw on ecological theory to provide a synthetic framework for understanding how land use change around protected areas may alter ecological processes and biodiversity within protected areas and to provide a basis for identifying scientifically based management alternatives. We first present a conceptual model of protected areas embedded within larger ecosystems that often include surrounding human land use. Drawing on case studies in this Invited Feature, we then explore a comprehensive set of ecological mechanisms by which land use on surrounding lands may influence ecological processes and biodiversity within reserves. These mechanisms involve changes in ecosystem size, with implications for minimum dynamic area, species-area effect, and trophic structure; altered flows of materials and disturbances into and out of reserves; effects on crucial habitats for seasonal and migration movements and population source/sink dynamics; and exposure to humans through hunting, poaching, exotics species, and disease. These ecological mechanisms provide a basis for assessing the vulnerability of protected areas to land use. They also suggest criteria for designing regional management to sustain protected areas in the context of surrounding human land use. These design criteria include maximizing the area of functional habitats, identifying and maintaining ecological process zones, maintaining key migration and source habitats, and managing human proximity and edge effects.

  18. Transient flow combustion

    Science.gov (United States)

    Tacina, R. R.

    1984-01-01

    Non-steady combustion problems can result from engine sources such as accelerations, decelerations, nozzle adjustments, augmentor ignition, and air perturbations into and out of the compressor. Also non-steady combustion can be generated internally from combustion instability or self-induced oscillations. A premixed-prevaporized combustor would be particularly sensitive to flow transients because of its susceptability to flashback-autoignition and blowout. An experimental program, the Transient Flow Combustion Study is in progress to study the effects of air and fuel flow transients on a premixed-prevaporized combustor. Preliminary tests performed at an inlet air temperature of 600 K, a reference velocity of 30 m/s, and a pressure of 700 kPa. The airflow was reduced to 1/3 of its original value in a 40 ms ramp before flashback occurred. Ramping the airflow up has shown that blowout is more sensitive than flashback to flow transients. Blowout occurred with a 25 percent increase in airflow (at a constant fuel-air ratio) in a 20 ms ramp. Combustion resonance was found at some conditions and may be important in determining the effects of flow transients.

  19. Evaluation of meat and bone meal combustion residue as lead immobilizing material for in situ remediation of polluted aqueous solutions and soils: "chemical and ecotoxicological studies".

    Science.gov (United States)

    Deydier, E; Guilet, R; Cren, S; Pereas, V; Mouchet, F; Gauthier, L

    2007-07-19

    As a result of bovine spongiform encephalopathy (BSE) crisis, meat and bone meal (MBM) production can no longer be used to feed cattle and must be safely disposed of or transformed. MBM specific incineration remains an alternative that could offer the opportunity to achieve both thermal valorization and solid waste recovery as ashes are calcium phosphate-rich material. The aim of this work is to evaluate ashes efficiency for in situ remediation of lead-contaminated aqueous solutions and soils, and to assess the bioavailability of lead using two biological models, amphibian Xenopus laevis larvae and Nicotiana tabaccum tobacco plant. With the amphibian model, no toxic or genotoxic effects of ashes are observed with concentrations from 0.1 to 5 g of ashes/L. If toxic and genotoxic effects of lead appear at concentration higher than 1 mg Pb/L (1 ppm), addition of only 100 mg of ashes/L neutralizes lead toxicity even with lead concentration up to 10 ppm. Chemical investigations (kinetics and X-ray diffraction (XRD) analysis) reveals that lead is quickly immobilized as pyromorphite [Pb10(PO4)6(OH)2] and lead carbonate dihydrate [PbCO(3).2H2O]. Tobacco experiments are realized on contaminated soils with 50, 100, 2000 and 10000 ppm of lead with and without ashes amendment (35.3g ashes/kg of soil). Tobacco measurements show that plant elongation is bigger in an ashes-amended soil contaminated with 10000 ppm of lead than on the reference soil alone. Tobacco model points out that ashes present two beneficial actions as they do not only neutralize lead toxicity but also act as a fertilizer.

  20. Combustion of environmentally altered molybdenum trioxide nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Kevin; Pantoya, Michelle L. [Mechanical Engineering Department, Texas Tech University, 2500 Broadway, Lubbock, TX 79409 (United States)

    2006-06-15

    Nanocomposite thermite mixtures are currently under development for many primer applications due to their high energy densities, high ignition sensitivity, and low release of toxins into the environment. However, variability and inconsistencies in combustion performance have not been sufficiently investigated. Environmental interactions with the reactants are thought to be a contributing factor to these variabilities. Combustion velocity experiments were conducted on aluminum (Al) and molybdenum trioxide (MoO{sub 3}) mixtures to investigate the role of environmental interactions such as light exposure and humidity. While the Al particles were maintained in an ambient, constant environment, the MoO{sub 3} particles were exposed to UV or fluorescent light, and highly humid environments. Results show that UV and fluorescent lighting over a period of days does not significantly contribute to performance deterioration. However, a humid environment severely decreases combustion performance if the oxidizer particles are not heat-treated. Heat treatment of the MoO{sub 3} greatly increases the material's ability to resist water absorption, yielding more repeatable combustion performance. This work further quantifies the role of the environment in the decrease of combustion performance of nanocomposites over time. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  1. Dioxins and polyvinylchloride in combustion and fires.

    Science.gov (United States)

    Zhang, Mengmei; Buekens, Alfons; Jiang, Xuguang; Li, Xiaodong

    2015-07-01

    This review on polyvinylchloride (PVC) and dioxins collects, collates, and compares data from selected sources on the formation of polychlorinated dibenzofurans (PCDFs) and dibenzo-p-dioxins (PCDDs), or in brief dioxins, in combustion and fires. In professional spheres, the incineration of PVC as part of municipal solid waste is seldom seen as a problem, since deep flue gas cleaning is required anyhow. Conversely, with its high content of chlorine, PVC is frequently branded as a major chlorine donor and spitefully leads to substantial formation of dioxins during poorly controlled or uncontrolled combustion and open fires. Numerous still ill-documented and diverse factors of influence may affect the formation of dioxins during combustion: on the one hand PVC-compounds represent an array of materials with widely different formulations; on the other hand these may all be exposed to fires of different nature and consequences. Hence, attention should be paid to PVC with respect to the ignition and development of fires, as well as attenuating the emission of objectionable compounds, such as carbon monoxide, hydrogen chloride, polycyclic aromatic hydrocarbons, and dioxins. This review summarises available dioxin emissions data, gathers experimental and simulation studies of fires and combustion tests involving PVC, and identifies and analyses the effects of several local factors of influence, affecting the formation of dioxins during PVC combustion. © The Author(s) 2015.

  2. Enhancement of Afterimage Colors by Surrounding Contours

    Directory of Open Access Journals (Sweden)

    Takao Sato

    2011-05-01

    Full Text Available Presenting luminance contours surrounding the adapted areas in test phase enhances color afterimages in both duration and color appearance. The presence of surrounding contour is crucial to some color phenomenon such as van Lier's afterimage, but the contour-effect itself has not been seriously examined. In this paper, we compared the contour-effect to color afterimages and to actually colored patches to examine the nature of color information subserving color-aftereffect. In the experiment, observers were adapted for 1 sec to a small colored square (red, green, yellow, or blue presented on a gray background. Then, a test field either with or without surrounding contour was presented. Observers matched the color of a test-patch located near the afterimage to the color of afterimage. It was found that the saturation of negative afterimage was almost doubled by the presence of surrounding contours. There was no effect of luminance contrast or polarity of contours. In contrast, no enhancement of saturation by surrounding contours was observed for actually colored patches even though the colors of patches were equalized to that of afterimage without contours. This dissociation in the contour-effect demonstrates the crucial difference between the color information for aftereffects and for ordinary bottom-up color perception.

  3. Combustion and regulation; Combustion et reglementation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    This conference was organized after the publication of the French by-law no 2010 relative to combustion installations and to the abatement of atmospheric pollution. Five topics were discussed during the conference: the new regulations, their content, innovations and modalities of application; the means of energy suppliers to face the new provisions and their schedule; the manufacturers proposals for existing installations and the new equipments; the administration control; and the impact of the new measures on exploitation and engineering. Twenty papers and 2 journal articles are reported in these proceedings. (J.S.)

  4. Dust Combustion Safety Issues for Fusion Applications

    Energy Technology Data Exchange (ETDEWEB)

    L. C. Cadwallader

    2003-05-01

    This report summarizes the results of a safety research task to identify the safety issues and phenomenology of metallic dust fires and explosions that are postulated for fusion experiments. There are a variety of metal dusts that are created by plasma erosion and disruptions within the plasma chamber, as well as normal industrial dusts generated in the more conventional equipment in the balance of plant. For fusion, in-vessel dusts are generally mixtures of several elements; that is, the constituent elements in alloys and the variety of elements used for in-vessel materials. For example, in-vessel dust could be composed of beryllium from a first wall coating, tungsten from a divertor plate, copper from a plasma heating antenna or diagnostic, and perhaps some iron and chromium from the steel vessel wall or titanium and vanadium from the vessel wall. Each of these elements has its own unique combustion characteristics, and mixtures of elements must be evaluated for the mixture’s combustion properties. Issues of particle size, dust temperature, and presence of other combustible materials (i.e., deuterium and tritium) also affect combustion in air. Combustion in other gases has also been investigated to determine if there are safety concerns with “inert” atmospheres, such as nitrogen. Several coolants have also been reviewed to determine if coolant breach into the plasma chamber would enhance the combustion threat; for example, in-vessel steam from a water coolant breach will react with metal dust. The results of this review are presented here.

  5. Combustion Byproducts Recycling Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower

    2008-08-31

    The Combustion Byproducts Recycling Consortium (CBRC) program was developed as a focused program to remove and/or minimize the barriers for effective management of over 123 million tons of coal combustion byproducts (CCBs) annually generated in the USA. At the time of launching the CBRC in 1998, about 25% of CCBs were beneficially utilized while the remaining was disposed in on-site or off-site landfills. During the ten (10) year tenure of CBRC (1998-2008), after a critical review, 52 projects were funded nationwide. By region, the East, Midwest, and West had 21, 18, and 13 projects funded, respectively. Almost all projects were cooperative projects involving industry, government, and academia. The CBRC projects, to a large extent, successfully addressed the problems of large-scale utilization of CCBs. A few projects, such as the two Eastern Region projects that addressed the use of fly ash in foundry applications, might be thought of as a somewhat smaller application in comparison to construction and agricultural uses, but as a novel niche use, they set the stage to draw interest that fly ash substitution for Portland cement might not attract. With consideration of the large increase in flue gas desulfurization (FGD) gypsum in response to EPA regulations, agricultural uses of FGD gypsum hold promise for large-scale uses of a product currently directed to the (currently stagnant) home construction market. Outstanding achievements of the program are: (1) The CBRC successfully enhanced professional expertise in the area of CCBs throughout the nation. The enhanced capacity continues to provide technology and information transfer expertise to industry and regulatory agencies. (2) Several technologies were developed that can be used immediately. These include: (a) Use of CCBs for road base and sub-base applications; (b) full-depth, in situ stabilization of gravel roads or highway/pavement construction recycled materials; and (c) fired bricks containing up to 30%-40% F

  6. Materialism.

    Science.gov (United States)

    Melnyk, Andrew

    2012-05-01

    Materialism is nearly universally assumed by cognitive scientists. Intuitively, materialism says that a person's mental states are nothing over and above his or her material states, while dualism denies this. Philosophers have introduced concepts (e.g., realization and supervenience) to assist in formulating the theses of materialism and dualism with more precision, and distinguished among importantly different versions of each view (e.g., eliminative materialism, substance dualism, and emergentism). They have also clarified the logic of arguments that use empirical findings to support materialism. Finally, they have devised various objections to materialism, objections that therefore serve also as arguments for dualism. These objections typically center around two features of mental states that materialism has had trouble in accommodating. The first feature is intentionality, the property of representing, or being about, objects, properties, and states of affairs external to the mental states. The second feature is phenomenal consciousness, the property possessed by many mental states of there being something it is like for the subject of the mental state to be in that mental state. WIREs Cogn Sci 2012, 3:281-292. doi: 10.1002/wcs.1174 For further resources related to this article, please visit the WIREs website. Copyright © 2012 John Wiley & Sons, Ltd.

  7. Optical Tomography in Combustion

    DEFF Research Database (Denmark)

    Evseev, Vadim

    spectral measurements at several line-of-sights with a view to applications for tomographic measurements on full-scale industrial combustion systems. The system was successfully applied on industrial scale for simultaneous fast exhaust gas temperature measurements in the three optical ports of the exhaust......D project, it was also important to investigate the spectral properties of major combustion species such as carbon dioxide and carbon monoxide in the infrared range at high temperatures to provide the theoretical background for the development of the optical tomography methods. The new software....... JQSRT 113 (2012) 2222, 10.1016/j.jqsrt.2012.07.015] included in the PhD thesis as an attachment. The knowledge and experience gained in the PhD project is the first important step towards introducing the advanced optical tomography methods of combustion diagnostics developed in the project to future...

  8. Internal combustion engine

    Science.gov (United States)

    Baker, Quentin A.; Mecredy, Henry E.; O'Neal, Glenn B.

    1991-01-01

    An improved engine is provided that more efficiently consumes difficult fuels such as coal slurries or powdered coal. The engine includes a precombustion chamber having a portion thereof formed by an ignition plug. The precombustion chamber is arranged so that when the piston is proximate the head, the precombustion chamber is sealed from the main cylinder or the main combustion chamber and when the piston is remote from the head, the precombustion chamber and main combustion chamber are in communication. The time for burning of fuel in the precombustion chamber can be regulated by the distance required to move the piston from the top dead center position to the position wherein the precombustion chamber and main combustion chamber are in communication.

  9. Explaining preferences for home surroundings and locations

    DEFF Research Database (Denmark)

    Andersen, Hans Skifter

    2011-01-01

    This article is based on a survey carried out in Denmark that asked a random sample of the population about their preferences for home surroundings and locations. It shows that the characteristics of social surroundings are very important and can be divided into three independent dimensions......: avoiding social nuisances, preferring social homogeneity and living close to one’s social network and place of origin. The study shows that most people have many detailed preferences, whereas some have very few. This confirms an earlier theory that some people are very connected to certain places...... with given characteristics and thus do not have priorities regarding home surroundings and locations. For others, mostly young people and singles, home is just a place to sleep and relax, whereas life is lived elsewhere. For this group, there are only preferences for location and there are few specific...

  10. Sodium leak and combustion experiment-II report. Evaluation result of damage of mild steel liner

    Energy Technology Data Exchange (ETDEWEB)

    Aoto, K.; Hirakawa, Y.; Kuroda, T. [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1996-09-01

    Several material analyses on damage of the floor liner made of a mild steel which was in the test cell of the second sodium leak and combustion experiment (Test-2) performed in OEC/PNC on June 7 in 1996 were carried out to clarify the following issues. (1) Difference of the corrosion mechanism of Test-2 liner to that of the first sodium leak and combustion experiment (Test-1) liner. (2) The vital factor which can desides corrosion mechanism and damage location. The following analyses were accomplished. (1) Microstructure observation, (2) EPMA for cross-section of vicinity of corroded area, (3) X-ray diffraction (XRD) for the interface between corrosion product-liner (mild steel). The differences between the corrosion mechanism of Test-1 liner which is seemed to be the same that of `MONJU` liner and that of Test-2 liner is discussed based on the results of these material analyses. As the result, the Na-Fe double oxidization with mechanical/chemical removal of reaction product can be occurred on the Test-1 and `MONJU` liner. On the other hand, a hot-corrosion, that is the molten salt type corrosion is subject to be thinning of the Test-2 liner. All failures of Test-2 liner surround at the halfway up a convex. Considering the above corrosion mechanism, that fact leads that significant damage is occurred at the molten salt level. (author)

  11. Fuel and combustion stratification study of Partially Premixed Combustion

    OpenAIRE

    Izadi Najafabadi, M.; Dam, N.; Somers, B.; Johansson, B.

    2016-01-01

    Relatively high levels of stratification is one of the main advantages of Partially Premixed Combustion (PPC) over the Homogeneous Charge Compression Ignition (HCCI) concept. Fuel stratification smoothens heat release and improves controllability of this kind of combustion. However, the lack of a clear definition of “fuel and combustion stratifications” is obvious in literature. Hence, it is difficult to compare stratification levels of different PPC strategies or other combustion concepts. T...

  12. Aerosols from biomass combustion

    Energy Technology Data Exchange (ETDEWEB)

    Nussbaumer, T

    2001-07-01

    This report is the proceedings of a seminar on biomass combustion and aerosol production organised jointly by the International Energy Agency's (IEA) Task 32 on bio energy and the Swiss Federal Office of Energy (SFOE). This collection of 16 papers discusses the production of aerosols and fine particles by the burning of biomass and their effects. Expert knowledge on the environmental impact of aerosols, formation mechanisms, measurement technologies, methods of analysis and measures to be taken to reduce such emissions is presented. The seminar, visited by 50 participants from 11 countries, shows, according to the authors, that the reduction of aerosol emissions resulting from biomass combustion will remain a challenge for the future.

  13. High Gravity (g) Combustion

    Science.gov (United States)

    2006-02-01

    UNICORN (Unsteady Ignition and Combustion with Reactions) code10. Flame propagation in a tube that is 50-mm wide and 1000-mm long (similar to that...turbine engine manufacturers, estimating the primary zone space heating rate. Both combustion systems, from Company A and Company B, required a much...MBTU/atm-hr-ft3) Te m pe ra tu re R is e (K ) dP/P = 2% dP/P = 2.5% dP/P = 3% dP/P = 3.5% dP/P = 4% Company A Company B Figure 13: Heat Release Rate

  14. Alcohol combustion chemistry

    KAUST Repository

    Sarathy, Mani

    2014-10-01

    Alternative transportation fuels, preferably from renewable sources, include alcohols with up to five or even more carbon atoms. They are considered promising because they can be derived from biological matter via established and new processes. In addition, many of their physical-chemical properties are compatible with the requirements of modern engines, which make them attractive either as replacements for fossil fuels or as fuel additives. Indeed, alcohol fuels have been used since the early years of automobile production, particularly in Brazil, where ethanol has a long history of use as an automobile fuel. Recently, increasing attention has been paid to the use of non-petroleum-based fuels made from biological sources, including alcohols (predominantly ethanol), as important liquid biofuels. Today, the ethanol fuel that is offered in the market is mainly made from sugar cane or corn. Its production as a first-generation biofuel, especially in North America, has been associated with publicly discussed drawbacks, such as reduction in the food supply, need for fertilization, extensive water usage, and other ecological concerns. More environmentally friendly processes are being considered to produce alcohols from inedible plants or plant parts on wasteland. While biofuel production and its use (especially ethanol and biodiesel) in internal combustion engines have been the focus of several recent reviews, a dedicated overview and summary of research on alcohol combustion chemistry is still lacking. Besides ethanol, many linear and branched members of the alcohol family, from methanol to hexanols, have been studied, with a particular emphasis on butanols. These fuels and their combustion properties, including their ignition, flame propagation, and extinction characteristics, their pyrolysis and oxidation reactions, and their potential to produce pollutant emissions have been intensively investigated in dedicated experiments on the laboratory and the engine scale

  15. Combustibility of tetraphenylborate solids

    International Nuclear Information System (INIS)

    Walker, D.D.

    1989-01-01

    Liquid slurries expected under normal in-tank processing (ITP) operations are not ignitible because of their high water content. However, deposits of dry solids from the slurries are combustible and produce dense, black smoke when burned. The dry solids burn similarly to Styrofoam and more easily than sawdust. It is the opinion of fire hazard experts that a benzene vapor deflagration could ignite the dry solids. A tetraphenylborate solids fire will rapidly plug the waste tank HEPA ventilation filters due to the nature of the smoke produced. To prevent ignition and combustion of these solids, the waste tanks have been equipped with a nitrogen inerting system

  16. Studies in combustion dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Koszykowski, M.L. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    The goal of this program is to develop a fundamental understanding and a quantitative predictive capability in combustion modeling. A large part of the understanding of the chemistry of combustion processes comes from {open_quotes}chemical kinetic modeling.{close_quotes} However, successful modeling is not an isolated activity. It necessarily involves the integration of methods and results from several diverse disciplines and activities including theoretical chemistry, elementary reaction kinetics, fluid mechanics and computational science. Recently the authors have developed and utilized new tools for parallel processing to implement the first numerical model of a turbulent diffusion flame including a {open_quotes}full{close_quotes} chemical mechanism.

  17. Combustion stratification for naphtha from CI combustion to PPC

    NARCIS (Netherlands)

    Vallinayagam, R.; Vedharaj, S.; An, Y.; Dawood, A.; Izadi Najafabadi, M.; Somers, L.M.T.; Johansson, B.H.

    2017-01-01

    This study demonstrated the change in combustion homogeneity from conventional diesel combustion via partially premixed combustion towards HCCI. Experiments are performed in an optical diesel engine at a speed of 1200 rpm with diesel fuel. Single injection strategy is employed and the fuel is

  18. Toxicology of Biodiesel Combustion products

    Science.gov (United States)

    1. Introduction The toxicology of combusted biodiesel is an emerging field. Much of the current knowledge about biological responses and health effects stems from studies of exposures to other fuel sources (typically petroleum diesel, gasoline, and wood) incompletely combusted. ...

  19. Mechanical Characteristics Analysis of Surrounding Rock on Anchor Bar Reinforcement

    Science.gov (United States)

    Gu, Shuan-cheng; Zhou, Pan; Huang, Rong-bin

    2018-03-01

    Through the homogenization method, the composite of rock and anchor bar is considered as the equivalent material of continuous, homogeneous, isotropic and strength parameter enhancement, which is defined as reinforcement body. On the basis of elasticity, the composite and the reinforcement are analyzed, Based on strengthening theory of surrounding rock and displacement equivalent conditions, the expression of reinforcement body strength parameters and mechanical parameters is deduced. The example calculation shows that the theoretical results are close to the results of the Jia-mei Gao[9], however, closer to the results of FLAC3D numerical simulation, it is proved that the model and surrounding rock reinforcement body theory are reasonable. the model is easy to analyze and calculate, provides a new way for determining reasonable bolt support parameters, can also provides reference for the stability analysis of underground cavern bolting support.

  20. Carbon Shale Combustion in the Fluidized Bed Reactor

    Directory of Open Access Journals (Sweden)

    Olek Małgorzata

    2014-06-01

    Full Text Available The purpose of this article is to present the possibilities of coal shale combustion in furnaces with bubbling fluidized bed. Coal shale can be autothermally combusted in the fluidized bed, despite the low calorie value and high ash content of fuel. Established concentrations of CO (500 ppm and VOC (30 mg/m3 have indicated a high conversion degree of combustible material during combustion process. Average concentrations of SO2 and NOx in the flue gas were higher than this received from the combustion of high quality hard coal, 600 ppm and 500 ppm, respectively. Optional reduction of SO2 and NOx emission may require the installation of flue gas desulphurization and de-NOx systems.

  1. Smart Chips for Smart Surroundings -- 4S

    NARCIS (Netherlands)

    Schuler, Eberhard; König, Ralf; Becker, Jürgen; Rauwerda, G.K.; van de Burgwal, M.D.; Smit, Gerardus Johannes Maria; Cardoso, João M.P.; Hübner, Michael

    2011-01-01

    The overall mission of the 4S project (Smart Chips for Smart Surroundings) was to define and develop efficient flexible, reconfigurable core building blocks, including the supporting tools, for future Ambient System Devices. Reconfigurability offers the needed flexibility and adaptability, it

  2. Childhood Suicide and Myths Surrounding It.

    Science.gov (United States)

    Greene, Dorothea B.

    1994-01-01

    Dispels five misconceptions surrounding the suicide of children: that children under the age of six do not commit suicide; that suicide in latency years is extremely rare; that psychodynamically and developmentally true depression is not possible in childhood; that child cannot understand finality of death; and that children are cognitively and…

  3. Underground treatment of combustible minerals

    Energy Technology Data Exchange (ETDEWEB)

    Sarapuu, E

    1954-10-14

    A process is described for treating oil underground, consisting in introducing several electrodes spaced one from the other in a bed of combustibles underground so that they come in electric contact with this bed of combustibles remaining insulated from the ground, and applying to the electrodes a voltage sufficient to produce an electric current across the bed of combustibles, so as to heat it and create an electric connection between the electrodes on traversing the bed of combustibles.

  4. Supersonic Combustion Ramjet Research

    Science.gov (United States)

    2012-08-01

    was in collaboration with Prof. R. Bowersox (Texas A&M University) and Dr. K. Kobayashi ( Japanese Aerospace Exploration Agency, JAXA). 4.2 Ignition... cinema stereoscopic PIV system for the measurement of micro- and meso-scale turbulent premixed flame dynamics,” Paper B13, 5th US Combustion

  5. Infrared monitoring of combustion

    International Nuclear Information System (INIS)

    Bates, S.C.; Morrison, P.W. Jr.; Solomon, P.R.

    1991-01-01

    In this paper, the use of Fourier Transform Infrared (FT-IR) spectroscopy for combustion monitoring is described. A combination of emission, transmission, and reflection FT-IR spectroscopy yields data on the temperature and composition of the gases, surfaces and suspended particles in the combustion environment. Detection sensitivity of such trace exhaust gases as CO, CO 2 , SO 2 , NO x , and unburned hydrocarbons is at the ppm level. Tomographic reconstruction converts line-of-sight measurements into spatially resolved temperature and concentration data. Examples from various combustion processes are used to demonstrate the capabilities of the technique. Industrial measurements are described that have been performed directly in the combustion zone and in the exhaust duct of a large chemical recovery boiler. Other measurements of hot slag show how FT-IR spectroscopy can determine the temperature and optical properties of surfaces. In addition, experiments with water droplets show that transmission FT-IR data yield spectra that characterize particle size and number density

  6. Combustible dust tests

    Science.gov (United States)

    The sugar dust explosion in Georgia on February 7, 2008 killed 14 workers and injured many others (OSHA, 2009). As a consequence of this explosion, OSHA revised its Combustible Dust National Emphasis (NEP) program. The NEP targets 64 industries with more than 1,000 inspections and has found more tha...

  7. Composite materials

    International Nuclear Information System (INIS)

    Sambrook, D.J.

    1976-01-01

    A superconductor composite is described comprising at least one longitudinally extending superconductor filament or bundle of sub-filaments, each filament or bundle of sub-filaments being surrounded by and in good electrical contact with a matrix material, the matrix material comprising a plurality of longitudinally extending cells of a metal of high electrical conductivity surrounded by a material of lower electrical conductivity. The high electrical conductivity material surrounding the superconducting filament or bundle of sub-filaments is interrupted by a radially extending wall of the material of the lower electrical conductivity, the arrangement being such that at least two superconductor filaments or sub-filaments are circumferentially circumscribed by a single annulus of the material of high electrical conductivity. The annulus is electrically interrupted by a radially extending wall of the material of low electrical conductivity

  8. Materials

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2009-02-01

    Full Text Available . It is generally included as part of a structurally insulated panel (SIP) where the foam is sandwiched between external skins of steel, wood or cement. Cement composites Cement bonded composites are an important class of building materials. These products... for their stone buildings, including the Egyptians, Aztecs and Inca’s. As stone is a very dense material it requires intensive heating to become warm. Rocks were generally stacked dry but mud, and later cement, can be used as a mortar to hold the rocks...

  9. Multiphase Combustion of Metalized Nanocomposite Energetic Materials

    Science.gov (United States)

    2014-12-19

    on thermal conductivity and absorption coefficient for consolidated aluminum nanoparticles, International Journal of Heat and Mass Transfer, (06...28. Stacy, S.C., Zhang, X., Pantoya, M.L., Weeks, B., Effect of Density on Thermal Conductivity and Absorption Coefficient for Consolidated Aluminum...energetic powder to ESD stimuli generated from a piezo electric crystal ( PZT ). Results show that a high PZT dielectric strength leads to faster

  10. Laboratory weathering of combusted oil shale

    International Nuclear Information System (INIS)

    Essington, M.E.

    1991-01-01

    The objective of this study was to examine the mineralogy and leachate chemistry of three combusted oil shales (two Green River Formation and one New Albany) in a laboratory weathering environment using the humidity cell technique. The mineralogy of the combusted western oil shales (Green River Formation) is process dependent. In general, processing resulted in the formation of anhydrite, lime, periclase, and hematite. During the initial stages of weathering, lime, periclase, and hematite. During the initial stages of weathering, lime, periclase, and anhydrite dissolve and ettringite precipitates. The initial leachates are highly alkaline, saline, and dominated by Na, hydroxide, and SO 4 . As weathering continues, ettringite precipitates. The initial leachates are highly alkaline, saline, and dominated by Na, hydroxide, and SO 4 . As weathering continues, ettringite dissolves, gypsum and calcite precipitate, and the leachates are dominated by Mg, SO 4 , and CO 3 . Leachate pH is rapidly reduced to between 8.5 and 9 with leaching. The combusted eastern oil shale (New Albany) is composed of quartz, illite, hematite, and orthoclase. Weathering results in the precipitation of gypsum. The combusted eastern oil shale did not display a potential to produce acid drainage. Leachate chemistry was dominated by Ca and SO 4 . Element concentrations continually decreased with weathering. IN a western disposal environment receiving minimal atmospheric precipitation, spent oil shale will remain in the initial stages of weathering, and highly alkaline and saline conditions will dominate leachate chemistry. In an eastern disposal environment, soluble salts will be rapidly removed from the spent oil shale to potentially affect the surrounding environment

  11. Impacts of Artificial Reefs on Surrounding Ecosystems

    Science.gov (United States)

    Manoukian, Sarine

    Artificial reefs are becoming a popular biological and management component in shallow water environments characterized by soft seabed, representing both important marine habitats and tools to manage coastal fisheries and resources. An artificial reef in the marine environment acts as an open system with exchange of material and energy, altering the physical and biological characteristics of the surrounding area. Reef stability will depend on the balance of scour, settlement, and burial resulting from ocean conditions over time. Because of the unstable nature of sediments, they require a detailed and systematic investigation. Acoustic systems like high-frequency multibeam sonar are efficient tools in monitoring the environmental evolution around artificial reefs, whereas water turbidity can limit visual dive and ROV inspections. A high-frequency multibeam echo sounder offers the potential of detecting fine-scale distribution of reef units, providing an unprecedented level of resolution, coverage, and spatial definition. How do artificial reefs change over time in relation to the coastal processes? How accurately does multibeam technology map different typologies of artificial modules of known size and shape? How do artificial reefs affect fish school behavior? What are the limitations of multibeam technology for investigating fish school distribution as well as spatial and temporal changes? This study addresses the above questions and presents results of a new approach for artificial reef seafloor mapping over time, based upon an integrated analysis of multibeam swath bathymetry data and geoscientific information (backscatter data analysis, SCUBA observations, physical oceanographic data, and previous findings on the geology and sedimentation processes, integrated with unpublished data) from Senigallia artificial reef, northwestern Adriatic Sea (Italy) and St. Petersburg Beach Reef, west-central Florida continental shelf. A new approach for observation of fish

  12. Low emission internal combustion engine

    Science.gov (United States)

    Karaba, Albert M.

    1979-01-01

    A low emission, internal combustion compression ignition engine having a cylinder, a piston movable in the cylinder and a pre-combustion chamber communicating with the cylinder near the top thereof and in which low emissions of NO.sub.x are achieved by constructing the pre-combustion chamber to have a volume of between 70% and 85% of the combined pre-chamber and main combustion chamber volume when the piston is at top dead center and by variably controlling the initiation of fuel injection into the pre-combustion chamber.

  13. Process gas generator feeding internal combustion piston engines

    Energy Technology Data Exchange (ETDEWEB)

    Iwantscheff, G; Kostka, H; Henkel, H J

    1978-10-26

    The invention relates to a process gas generator feeding gaseous fuel to internal combustion piston engines. The cylinder linings of the internal combustion engine are enclosed by the catalytic reaction chamber of the process gas generator which contains perforated sintered nozzle bricks as carriers of the catalysts needed for the conversion. The reaction chamber is surrounded by the exhaust gas chamber around which a tube coil is ound which feeds the fuel charge to the reaction chamber after evaporation and mixing with exhaust gas and air. The fuel which may be used for this purpose, e.g., is low-octane gasoline or diesel fuel. In the reaction chamber the fuel is catalytically converted at temperatures above 200/sup 0/C, e.g., into low-molecular paraffins, carbon monoxide and hydrogen. Operation of the internal combustion engine with a process gas generator greatly reduces the pollutant content of the exhaust gases.

  14. Hydrogen assisted diesel combustion

    Energy Technology Data Exchange (ETDEWEB)

    Lilik, Gregory K.; Boehman, Andre L. [The EMS Energy Institute, The Pennsylvania State University, University Park, PA 16802 (United States); Zhang, Hedan; Haworth, Daniel C. [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Herreros, Jose Martin [Escuela Tecnica Superior de Ingenieros Industriales, Universidad de Castilla La-Mancha, Avda. Camilo Jose Cela s/n, 13071 Ciudad Real (Spain)

    2010-05-15

    Hydrogen assisted diesel combustion was investigated on a DDC/VM Motori 2.5L, 4-cylinder, turbocharged, common rail, direct injection light-duty diesel engine, with a focus on exhaust emissions. Hydrogen was substituted for diesel fuel on an energy basis of 0%, 2.5%, 5%, 7.5%, 10% and 15% by aspiration of hydrogen into the engine's intake air. Four speed and load conditions were investigated (1800 rpm at 25% and 75% of maximum output and 3600 rpm at 25% and 75% of maximum output). A significant retarding of injection timing by the engine's electronic control unit (ECU) was observed during the increased aspiration of hydrogen. The retarding of injection timing resulted in significant NO{sub X} emission reductions, however, the same emission reductions were achieved without aspirated hydrogen by manually retarding the injection timing. Subsequently, hydrogen assisted diesel combustion was examined, with the pilot and main injection timings locked, to study the effects caused directly by hydrogen addition. Hydrogen assisted diesel combustion resulted in a modest increase of NO{sub X} emissions and a shift in NO/NO{sub 2} ratio in which NO emissions decreased and NO{sub 2} emissions increased, with NO{sub 2} becoming the dominant NO{sub X} component in some combustion modes. Computational fluid dynamics analysis (CFD) of the hydrogen assisted diesel combustion process captured this trend and reproduced the experimentally observed trends of hydrogen's effect on the composition of NO{sub X} for some operating conditions. A model that explicitly accounts for turbulence-chemistry interactions using a transported probability density function (PDF) method was better able to reproduce the experimental trends, compared to a model that ignores the influence of turbulent fluctuations on mean chemical production rates, although the importance of the fluctuations is not as strong as has been reported in some other recent modeling studies. The CFD results confirm

  15. Modification of combustion aerosols in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Weingartner, E [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-07-01

    Combustion aerosols particles are released on large scale into the atmosphere in the industrialized regions as well as in the tropics (by wood fires). The particles are subjected to various aging processes which depend on the size, morphology, and chemical composition of the particles. The interaction of combustion particles with sunlight and humidity as well as adsorption and desorption of volatile material to or from the particles considerably changes their physical and chemical properties and thus their residence time in the atmosphere. This is of importance because combustion particles are known to have a variety of health effects on people. Moreover, atmospheric aerosol particles have an influence on climate, directly through the reflection and absorption of solar radiation and indirectly through modifying the optical properties and lifetime of clouds. In a first step, a field experiment was carried out to study the sources and characteristics of combustion aerosols that are emitted from vehicles in a road tunnel. It was found that most of the fine particles were tail pipe emissions of diesel powered vehicles. The calculation shows that on an average these vehicles emit about 300 mg fine particulate matter per driven kilometer. This emission factor is at least 100 times higher than the mean emission factor estimated for gasoline powered vehicles. Furthermore, it is found that during their residence time in the tunnel, the particles undergo significant changes: The particles change towards a more compact structure. The conclusion is reached that this is mainly due to adsorption of volatile material from the gas phase to the particle surface. In the atmosphere, the life cycle as well as the radiative and chemical properties of an aerosol particle is strongly dependent on its response to humidity. Therefore the hygroscopic behavior of combustion particles emitted from single sources (i.e. from a gasoline and a diesel engine) were studied in laboratory experiments.

  16. Ammonium nitrate: combustion mechanism and the role of additives

    Energy Technology Data Exchange (ETDEWEB)

    Sinditskii, Valery P.; Egorshev, Viacheslav Yu.; Levshenkov, Anton I.; Serushkin, Valery V. [Department of Chemical Engineering, Mendeleev University of Chemical Technology, 9 Miusskaya Sq., 125047, Moscow (Russian Federation)

    2005-09-01

    This paper presents an analysis of the observed combustion behavior of AN mixtures with different additives, fuels, and energetic materials. It has been determined on the basis of flame structure investigation by fine tungsten-rhenium thermocouples that the surface temperature of AN is controlled by the dissociation reaction of the salt occurring at the surface. Results obtained have indicated that the leading reaction of combustion of AN doped with additives proceeds in the condensed phase up to pressures of 20-30 MPa. A reason for the inability of pure AN to burn is suggested and the role of additives in the combustion mechanism is discussed. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  17. Induced radioactivity in a 4 MW target and its surroundings

    CERN Document Server

    Agosteo, Stefano; Otto, Thomas; Silari, Marco

    2003-01-01

    An important aspect of a future CERN Neutrino Factory is the material activation arising from a 2.2 GeV, 4 MW proton beam striking a mercury target. An estimation of the hadronic inelastic interactions and the production of residual nuclei in the target, the magnetic horn, the decay tunnel, the surrounding rock and a downstream dump was performed by the Monte Carlo hadronic cascade code FLUKA. The aim was both to assess the dose equivalent rate to be expected during maintenance work and to evaluate the amount of residual radioactivity, which will have to be disposed of after the facility has ceased operation.

  18. Emergency response mobile robot for operations in combustible atmospheres

    Science.gov (United States)

    Stone, Henry W. (Inventor); Ohm, Timothy R. (Inventor)

    1995-01-01

    A mobile, self-powered, self-contained, and remote-controlled robot is presented. The robot is capable of safely operating in a combustible atmosphere and providing information about the atmosphere to the operator. The robot includes non-sparking and non-arcing electro-mechanical and electronic components designed to prevent the robot from igniting the combustible atmosphere. The robot also includes positively pressurized enclosures that house the electromechanical and electronic components of the robot and prevent intrusion of the combustible atmosphere into the enclosures. The enclosures are interconnected such that a pressurized gas injected into any one of the enclosures is routed to all the other enclosures through the interconnections. It is preferred that one or more sealed internal channels through structures intervening between the enclosures be employed. Pressure transducers for detecting if the pressure within the enclosures falls below a predetermined level are included. The robot also has a sensing device for determining the types of combustible substances in the surrounding atmosphere, as well as the concentrations of each type of substance relative to a pre-determined lower explosive limit (LEL). In addition, the sensing device can determine the percent level of oxygen present in the surrounding atmosphere.

  19. An emergency response mobile robot for operations in combustible atmospheres

    Science.gov (United States)

    Stone, Henry W. (Inventor); Ohm, Timothy R. (Inventor)

    1993-01-01

    A mobile, self-powered, self-contained, and remote-controlled robot is presented. The robot is capable of safely operating in a combustible atmosphere and providing information about the atmosphere to the operator. The robot includes non-sparking and non-arcing electro-mechanical and electronic components designed to prevent the robot from igniting the combustible atmosphere. The robot also includes positively pressurized enclosures that house the electromechanical and electronic components of the robot and prevent intrusion of the combustible atmosphere into the enclosures. The enclosures are interconnected such that a pressurized gas injected into any one of the enclosures is routed to all the other enclosures through the interconnections. It is preferred that one or more sealed internal channels through structures intervening between the enclosures be employed. Pressure transducers for detecting if the pressure within the enclosures falls below a predetermined level are included. The robot also has a sensing device for determining the types of combustible substances in the surrounding atmosphere, as well as the concentrations of each type of substance relative to a pre-determined lower explosive limit (LEL). In addition, the sensing device can determine the percent level of oxygen present in the surrounding atmosphere.

  20. Combustion strategy : United Kingdom

    Energy Technology Data Exchange (ETDEWEB)

    Greenhalgh, D. [Heriot-Watt Univ., Edingburgh, Scotland (United Kingdom). School of Engineering and Physical Sciences

    2009-07-01

    The United Kingdom's combustion strategy was briefly presented. Government funding sources for universities were listed. The United Kingdom Research Councils that were listed included the Arts and Humanities Research Council (AHRC) and the Biotechnology and Biological Sciences Research Council (BBSRC); the Engineering and Physical Sciences Research Council (EPSRC); the Economic and Social Research Council; the Medical Research Council; the Natural Environment Research Council; and the Science and Technology Facilities Council. The EPSRC supported 65 grants worth 30.5 million pounds. The combustion industry was noted to be dominated by three main players of which one was by far the largest. The 3 key players were Rolls-Royce; Jaguar Land Rover; and Doosan Babcock. Industry and government involvement was also discussed for the BIS Technology Strategy Board, strategy technology areas, and strategy application areas.

  1. Aerosols from biomass combustion

    Energy Technology Data Exchange (ETDEWEB)

    Nussbaumer, T.

    2001-07-01

    This report is the proceedings of a seminar on biomass combustion and aerosol production organised jointly by the International Energy Agency's (IEA) Task 32 on bio energy and the Swiss Federal Office of Energy (SFOE). This collection of 16 papers discusses the production of aerosols and fine particles by the burning of biomass and their effects. Expert knowledge on the environmental impact of aerosols, formation mechanisms, measurement technologies, methods of analysis and measures to be taken to reduce such emissions is presented. The seminar, visited by 50 participants from 11 countries, shows, according to the authors, that the reduction of aerosol emissions resulting from biomass combustion will remain a challenge for the future.

  2. Ignition of a combustible half space

    Science.gov (United States)

    Olmstead, W. E.

    1983-01-01

    A half space of combustible material is subjected to an arbitrary energy flux at the boundary where convection heat loss is also allowed. An asymptotic analysis of the temperature growth reveals two conditions necessary for ignition to occur. Cases of both large and order unity Lewis number are shown to lead to a nonlinear integral equation governing the thermal runaway. Some global and asymptotic properties of the integral equation are obtained.

  3. Extinguishing agent for combustible metal fires

    Science.gov (United States)

    Riley, John F.; Stauffer, Edgar Eugene

    1976-10-12

    A low chloride extinguishing agent for combustible metal fires comprising from substantially 75 to substantially 94 weight percent of sodium carbonate as the basic fire extinguishing material, from substantially 1 to substantially 5 weight percent of a water-repellent agent such as a metal stearate, from substantially 2 to substantially 10 weight percent of a flow promoting agent such as attapulgus clay, and from substantially 3 to substantially 15 weight percent of a polyamide resin as a crusting agent.

  4. NOx Emission Reduction by Oscillating Combustion

    Energy Technology Data Exchange (ETDEWEB)

    John C. Wagner

    2004-03-31

    High-temperature, natural gas-fired furnaces, especially those fired with preheated air, produce large quantities of NO{sub x} per ton of material processed. Regulations on emissions from industrial furnaces are becoming increasingly more stringent. In addition, competition is forcing operators to make their furnaces more productive and/or efficient. Switching from preheated air to industrial oxygen can increase efficiency and reduce NO{sub x}, but oxygen is significantly more costly than air and may not be compatible with the material being heated. What was needed, and what was developed during this project, is a technology that reduces NO{sub x} emissions while increasing furnace efficiency for both air- and oxy-fired furnaces. Oscillating combustion is a retrofit technology that involves the forced oscillation of the fuel flow rate to a furnace. These oscillations create successive, fuel-rich and fuel-lean zones within the furnace. Heat transfer from the flame to the load increases due to the more luminous fuel-rich zones, a longer overall flame length, and the breakup of the thermal boundary layer. The increased heat transfer shortens heat up times, thereby increasing furnace productivity, and reduces the heat going up the stack, thereby increasing efficiency. The fuel-rich and fuel-lean zones also produce substantially less NO{sub x} than firing at a constant excess air level. The longer flames and higher heat transfer rate reduces overall peak flame temperature and thus reduces additional NO{sub x} formation from the eventual mixing of the zones and burnout of combustibles from the rich zones. This project involved the development of hardware to implement oscillating combustion on an industrial scale, the laboratory testing of oscillating combustion on various types of industrial burners, and the field testing of oscillating combustion on several types of industrial furnace. Before laboratory testing began, a market study was conducted, based on the

  5. NOx Emission Reduction by Oscillating combustion

    Energy Technology Data Exchange (ETDEWEB)

    Institute of Gas Technology

    2004-01-30

    High-temperature, natural gas-fired furnaces, especially those fired with preheated air, produce large quantities of NO{sub x} per ton of material processed. Regulations on emissions from industrial furnaces are becoming increasingly more stringent. In addition, competition is forcing operators to make their furnaces more productive and/or efficient. Switching from preheated air to industrial oxygen can increase efficiency and reduce NO{sub x}, but oxygen is significantly more costly than air and may not be compatible with the material being heated. What was needed, and what was developed during this project, is a technology that reduces NO{sub x} emissions while increasing furnace efficiency for both air- and oxy-fired furnaces. Oscillating combustion is a retrofit technology that involves the forced oscillation of the fuel flow rate to a furnace. These oscillations create successive, fuel-rich and fuel-lean zones within the furnace. Heat transfer from the flame to the load increases due to the more luminous fuel-rich zones, a longer overall flame length, and the breakup of the thermal boundary layer. The increased heat transfer shortens heat up times, thereby increasing furnace productivity, and reduces the heat going up the stack, thereby increasing efficiency. The fuel-rich and fuel-lean zones also produce substantially less NO{sub x} than firing at a constant excess air level. The longer flames and higher heat transfer rate reduces overall peak flame temperature and thus reduces additional NO{sub x} formation from the eventual mixing of the zones and burnout of combustibles from the rich zones. This project involved the development of hardware to implement oscillating combustion on an industrial scale, the laboratory testing of oscillating combustion on various types of industrial burners, and the field testing of oscillating combustion on several types of industrial furnace. Before laboratory testing began, a market study was conducted, based on the

  6. Plasma Assisted Combustion

    Science.gov (United States)

    2007-02-28

    Tracking an individual streamer branch among others in a pulsed induced discharge J. Phys. D: Appl. Phys. 35 2823--9 [29] van Veldhuizen E M and Rutgers...2005) AIAA–2005–0405. [99] E.M. Van Veldhuizen (ed) Electrical Discharges for Environmental Purposes: Fun- damentals and Applications (New York: Nova...Vandooren J, Van Tiggelen P J 1977 Reaction Mechanism and Rate Constants in Lean Hydrogen–Nitrous Oxide Flames Combust. Flame 28 165 [201] Dean A M, Steiner

  7. Fluid-bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, G.; Schoebotham, N.

    1981-02-01

    In Energy Equipment Company's two-stage fluidized bed system, partial combustion in a fluidized bed is followed by burn-off of the generated gases above the bed. The system can be retrofitted to existing boilers, and can burn small, high ash coal efficiently. It has advantages when used as a hot gas generator for process drying. Tests on a boiler at a Cadbury Schweppes plant are reported.

  8. Combustion science and engineering

    CERN Document Server

    Annamalai, Kalyan

    2006-01-01

    Introduction and Review of Thermodynamics Introduction Combustion Terminology Matter and Its Properties Microscopic Overview of Thermodynamics Conservation of Mass and Energy and the First Law of Thermodynamics The Second Law of Thermodynamics Summary Stoichiometry and Thermochemistry of Reacting Systems Introduction Overall Reactions Gas Analyses Global Conservation Equations for Reacting Systems Thermochemistry Summary Appendix Reaction Direction and Equilibrium Introduction Reaction Direction and Chemical Equilibrium Chemical Equilibrium Relations Vant Hoff Equation Adi

  9. Combustion Gases And Heat Release Analysis During Flame And Flameless Combustion Of Wood Pellets

    Directory of Open Access Journals (Sweden)

    Horváth Jozef

    2015-06-01

    Full Text Available With the growing prices of fossil fuels, alternative fuels produced of biomass come to the fore. They are made of waste materials derived from the processing of wood and wood materials. The main objective of this study was to analyse the fire-technical characteristics of wood pellets. The study analysed three dust samples acquired from wood pellets made of various types of wood biomass. Wood pellet dust is produced when manipulating with pellets. During this process a potentially hazardous situations may occur. Biomass is chemically composed mostly of hemicellulose, cellulose and lignin. During straining of the biomass by heat flux, combustion initiation occurs. Also, there was a change in the composition of material throughout combustion gases production, and the amount of heat generated by a flame or flameless combustion. Measurement of fire characteristics was conducted according to ISO 5660-1 standard using a cone calorimeter. Two samples of wood pellet dust were tested under the heat flux of 35 kW.m−2 and 50 kW.m−2. The process of combustion, the time to ignition, the carbon monoxide concentration and the amount of released heat were observed.

  10. The Diesel Combustion Collaboratory: Combustion Researchers Collaborating over the Internet

    Energy Technology Data Exchange (ETDEWEB)

    C. M. Pancerella; L. A. Rahn; C. Yang

    2000-02-01

    The Diesel Combustion Collaborator (DCC) is a pilot project to develop and deploy collaborative technologies to combustion researchers distributed throughout the DOE national laboratories, academia, and industry. The result is a problem-solving environment for combustion research. Researchers collaborate over the Internet using DCC tools, which include: a distributed execution management system for running combustion models on widely distributed computers, including supercomputers; web-accessible data archiving capabilities for sharing graphical experimental or modeling data; electronic notebooks and shared workspaces for facilitating collaboration; visualization of combustion data; and video-conferencing and data-conferencing among researchers at remote sites. Security is a key aspect of the collaborative tools. In many cases, the authors have integrated these tools to allow data, including large combustion data sets, to flow seamlessly, for example, from modeling tools to data archives. In this paper the authors describe the work of a larger collaborative effort to design, implement and deploy the DCC.

  11. Internal combustion engine using premixed combustion of stratified charges

    Science.gov (United States)

    Marriott, Craig D [Rochester Hills, MI; Reitz, Rolf D [Madison, WI

    2003-12-30

    During a combustion cycle, a first stoichiometrically lean fuel charge is injected well prior to top dead center, preferably during the intake stroke. This first fuel charge is substantially mixed with the combustion chamber air during subsequent motion of the piston towards top dead center. A subsequent fuel charge is then injected prior to top dead center to create a stratified, locally richer mixture (but still leaner than stoichiometric) within the combustion chamber. The locally rich region within the combustion chamber has sufficient fuel density to autoignite, and its self-ignition serves to activate ignition for the lean mixture existing within the remainder of the combustion chamber. Because the mixture within the combustion chamber is overall premixed and relatively lean, NO.sub.x and soot production are significantly diminished.

  12. Coal Combustion Products Extension Program

    Energy Technology Data Exchange (ETDEWEB)

    Tarunjit S. Butalia; William E. Wolfe

    2006-01-11

    This final project report presents the activities and accomplishments of the ''Coal Combustion Products Extension Program'' conducted at The Ohio State University from August 1, 2000 to June 30, 2005 to advance the beneficial uses of coal combustion products (CCPs) in highway and construction, mine reclamation, agricultural, and manufacturing sectors. The objective of this technology transfer/research program at The Ohio State University was to promote the increased use of Ohio CCPs (fly ash, FGD material, bottom ash, and boiler slag) in applications that are technically sound, environmentally benign, and commercially competitive. The project objective was accomplished by housing the CCP Extension Program within The Ohio State University College of Engineering with support from the university Extension Service and The Ohio State University Research Foundation. Dr. Tarunjit S. Butalia, an internationally reputed CCP expert and registered professional engineer, was the program coordinator. The program coordinator acted as liaison among CCP stakeholders in the state, produced information sheets, provided expertise in the field to those who desired it, sponsored and co-sponsored seminars, meetings, and speaking at these events, and generally worked to promote knowledge about the productive and proper application of CCPs as useful raw materials. The major accomplishments of the program were: (1) Increase in FGD material utilization rate from 8% in 1997 to more than 20% in 2005, and an increase in overall CCP utilization rate of 21% in 1997 to just under 30% in 2005 for the State of Ohio. (2) Recognition as a ''voice of trust'' among Ohio and national CCP stakeholders (particularly regulatory agencies). (3) Establishment of a national and international reputation, especially for the use of FGD materials and fly ash in construction applications. It is recommended that to increase Ohio's CCP utilization rate from 30% in 2005 to

  13. Development of flameless combustion; Desarrollo de la combustion sin flama

    Energy Technology Data Exchange (ETDEWEB)

    Flores Sauceda, M. Leonardo; Cervantes de Gortari, Jaime Gonzalo [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: 8344afc@prodigy.net.mx; jgonzalo@servidor.unam.mx

    2010-11-15

    The paper intends contribute to global warming mitigation joint effort that develops technologies to capture the CO{sub 2} produced by fossil fuels combustion and to reduce emission of other greenhouse gases like the NO{sub x}. After reviewing existing combustion bibliography is pointed out that (a) touches only partial aspects of the collective system composed by Combustion-Heat transfer process-Environment, whose interactions are our primary interest and (b) most specialists think there is not yet a clearly winning technology for CO{sub 2} capture and storage. In this paper the study of combustion is focused as integrated in the aforementioned collective system where application of flameless combustion, using oxidant preheated in heat regenerators and fluent gas recirculation into combustion chamber plus appropriated heat and mass balances, simultaneously results in energy saving and environmental impact reduction. [Spanish] El trabajo pretende contribuir al esfuerzo conjunto de mitigacion del calentamiento global que aporta tecnologias para capturar el CO{sub 2} producido por la combustion de combustibles fosiles y para disminuir la emision de otros gases invernadero como NOx. De revision bibliografica sobre combustion se concluye que (a) trata aspectos parciales del sistema compuesto por combustion-proceso de trasferencia de calor-ambiente, cuyas interacciones son nuestro principal interes (b) la mayoria de especialistas considera no hay todavia una tecnologia claramente superior a las demas para captura y almacenaje de CO{sub 2}. Se estudia la combustion como parte integrante del mencionado sistema conjunto, donde la aplicacion de combustion sin flama, empleando oxidante precalentado mediante regeneradores de calor y recirculacion de gases efluentes ademas de los balances de masa y energia adecuados, permite tener simultaneamente ahorros energeticos e impacto ambiental reducido.

  14. Opportunity's Surroundings on Sol 1818 (Vertical)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends. This view is presented as a vertical projection with geometric seam correction. North is at the top. The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view. The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

  15. Opportunity's Surroundings on Sol 1818 (Polar)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends. This view is presented as a polar projection with geometric seam correction. North is at the top. The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view. The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

  16. Crust Structure Data of Seas Surrounding Turkey

    International Nuclear Information System (INIS)

    Maden, N.; Gelisli, K.

    2007-01-01

    Black Sea, Aegean, Mediterranean and Marmara Sea, which surround the Turkey, have not been examined with respect to the Geological, Geophysical and other natural sciences sufficiently. In fact, it is not attach importance the Turkish seas adequately and abandoned with respect to the scientific researches. The most important reason of this situation is the lack of the education of the Marine Sciences in the Turkish Universities. In this study, it is tried to construct a crustal structure data base of the surrounding seas of the Turkey by collecting crustal structure data sets done by different authors in different times so far. The data acquired in the base are collected from different data base sources by dragging. The Moho depth in the eastern and western basin of the Black sea is 22 km and 19 km, respectively. In the Marmara Sea the Moho depth is 24 km. The moho value in the southern Aegean is 20 km, in the northern Aegean the moho depth is 30 km. on the other hand, the moho depth value in the eastern and western basin of the Mediterranean Sea are 15-20 km and 25-30 km, respectively

  17. Sulfur Chemistry in Combustion I

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Glarborg, Peter

    2000-01-01

    of the sulphur compounds in fossil fuels and the possibilities to remove them will be given. Then the combustion of sulphur species and their influence on the combustion chemistry and especially on the CO oxidation and the NOx formation will be described. Finally the in-situ removal of sulphur in the combustion...... process by reaction between SO2 and calcium containing sorbents and the influence on the NOx chemistry will be treated....

  18. Pulsating combustion - Combustion characteristics and reduction of emissions

    Energy Technology Data Exchange (ETDEWEB)

    Lindholm, Annika

    1999-11-01

    In the search for high efficiency combustion systems pulsating combustion has been identified as one of the technologies that potentially can meet the objectives of clean combustion and good fuel economy. Pulsating combustion offers low emissions of pollutants, high heat transfer and efficient combustion. Although it is an old technology, the interest in pulsating combustion has been renewed in recent years, due to its unique features. Various applications of pulsating combustion can be found, mainly as drying and heating devices, of which the latter also have had commercial success. It is, however, in the design process of a pulse combustor, difficult to predict the operating frequency, the heat release etc., due to the lack of a well founded theory of the phenomenon. Research concerning control over the combustion process is essential for developing high efficiency pulse combustors with low emissions. Natural gas fired Helmholtz type pulse combustors have been the experimental objects of this study. In order to investigate the interaction between the fluid dynamics and the chemistry in pulse combustors, laser based measuring techniques as well as other conventional measuring techniques have been used. The experimental results shows the possibilities to control the combustion characteristics of pulsating combustion. It is shown that the time scales in the large vortices created at the inlet to the combustion chamber are very important for the operation of the pulse combustor. By increasing/decreasing the time scale for the large scale mixing the timing of the heat release is changed and the operating characteristics of the pulse combustor changes. Three different means for NO{sub x} reduction in Helmholtz type pulse combustors have been investigated. These include exhaust gas recirculation, alteration of air/fuel ratio and changed inlet geometry in the combustion chamber. All used methods achieved less than 10 ppm NO{sub x} emitted (referred to stoichiometric

  19. Fiscal 1993 achievement report. International Clean Energy Network Using Hydrogen Conversion (WE-NET) technology (Subtask 8 - Research and development of hydrogen combustion turbine - Development of ultrahigh-temperature materials); 1993 nendo seika hokokusho. Suiso riyo kokusai clean energy system gijutsu (WE-NET). (Subtask 8. Suiso nensho tabin no kaihatsu - Cho koon zairyo no kaihatsu no kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-03-01

    Current technologies are surveyed and tasks to discharge are extracted relating to heat resistant alloys, intermetallic compounds, ceramic based composite materials, and carbon based composite materials, which are expected to be used for hydrogen combustion turbines. Concerning oxide dispersion strengthened alloys for cooled vanes, tasks to discharge are extracted, which relate to the designing, development, and selection of vane materials, bonding layer materials, and coating materials, and to thermal barrier coating techniques and machining techniques. Concerning porous fiber reinforced ceramic materials for ceramic shells, tasks involve the elucidation of corrosion behavior and manufacturing techniques. MoSi{sub 2}, which is a promising high-melting intermetallic compound, also presents some tasks to discharge for an increase in its high strength and high ductility in an ultrahigh-temperature steam/reducing atmosphere, and for improvement in manufacturing techniques. For the carbon/carbon composite material which is the sole material usable in the ultrahigh-temperature domain of 2,000 degrees C, an analysis and evaluation method taking its anisotropy into consideration needs to be developed, and an oxidation resistant coating has to be also developed. In addition to the designing and development of these materials, development is necessary of materials testing and evaluating techniques. (NEDO)

  20. Combustion from basics to applications

    CERN Document Server

    Lackner, Maximilian; Winter, Franz

    2013-01-01

    Combustion, the process of burning, is defined as a chemical reaction between a combustible reactant (the fuel) and an oxidizing agent (such as air) in order to produce heat and in most cases light while new chemical species (e.g., flue gas components) are formed. This book covers a gap on the market by providing a concise introduction to combustion. Most of the other books currently available are targeted towards the experienced users and contain too many details and/or contain knowledge at a fairly high level. This book provides a brief and clear overview of the combustion basics, suitable f

  1. Mathematical Modeling in Combustion Science

    CERN Document Server

    Takeno, Tadao

    1988-01-01

    An important new area of current research in combustion science is reviewed in the contributions to this volume. The complicated phenomena of combustion, such as chemical reactions, heat and mass transfer, and gaseous flows, have so far been studied predominantly by experiment and by phenomenological approaches. But asymptotic analysis and other recent developments are rapidly changing this situation. The contributions in this volume are devoted to mathematical modeling in three areas: high Mach number combustion, complex chemistry and physics, and flame modeling in small scale turbulent flow combustion.

  2. Thermoelectric Performance Enhancement by Surrounding Crystalline Semiconductors with Metallic Nanoparticles

    Science.gov (United States)

    Kim, Hyun-Jung; King, Glen C.; Park, Yeonjoon; Lee, Kunik; Choi, Sang H.

    2011-01-01

    Direct conversion of thermal energy to electricity by thermoelectric (TE) devices may play a key role in future energy production and utilization. However, relatively poor performance of current TE materials has slowed development of new energy conversion applications. Recent reports have shown that the dimensionless Figure of Merit, ZT, for TE devices can be increased beyond the state-of-the-art level by nanoscale structuring of materials to reduce their thermal conductivity. New morphologically designed TE materials have been fabricated at the NASA Langley Research Center, and their characterization is underway. These newly designed materials are based on semiconductor crystal grains whose surfaces are surrounded by metallic nanoparticles. The nanoscale particles are used to tailor the thermal and electrical conduction properties for TE applications by altering the phonon and electron transport pathways. A sample of bismuth telluride decorated with metallic nanoparticles showed less thermal conductivity and twice the electrical conductivity at room temperature as compared to pure Bi2Te3. Apparently, electrons cross easily between semiconductor crystal grains via the intervening metallic nanoparticle bridges, but phonons are scattered at the interfacing gaps. Hence, if the interfacing gap is larger than the mean free path of the phonon, thermal energy transmission from one grain to others is reduced. Here we describe the design and analysis of these new materials that offer substantial improvements in thermoelectric performance.

  3. Fluidised-bed combustion of gasification residue

    Energy Technology Data Exchange (ETDEWEB)

    Korpela, T.; Kudjoi, A.; Hippinen, I.; Heinolainen, A.; Suominen, M.; Lu Yong [Helsinki Univ. of Technology (Finland). Lab of Energy Economics and Power Plant Engineering

    1996-12-01

    Partial gasification processes have been presented as possibilities for future power production. In the processes, the solid materials removed from a gasifier (i.e. fly ash and bed material) contain unburnt fuel and the fuel conversion is increased by burning this gasification residue either in an atmospheric or a pressurised fluidised-bed. In this project, which is a part of European JOULE 2 EXTENSION research programme, the main research objectives are the behaviour of calcium and sulphur compounds in solids and the emissions of sulphur dioxide and nitrogen oxides (NO{sub x} and N{sub 2}O) in pressurised fluidised-bed combustion of gasification residues. (author)

  4. The combustion of sodium

    International Nuclear Information System (INIS)

    Newman, R.N.

    1978-01-01

    The burning rates of sodium in the form of vapour jets, droplets, sprays and unconfined and confined pools have been reviewed. Attention has been paid to assessing the value of models in the various combustion modes. Additional models have been constructed for the descriptions of laminar and turbulent vapour jets, stationary droplets, forced convection over ambient pool fires together with correlations for peak pressures in confined pool environments. Where appropriate experiments with sodium have not been conducted, the likely behaviour is predicted by comparison with the burning of other fuels, particularly in the field of large free ambient fires. Some areas where further knowledge is required are highlighted. (author)

  5. Fuel and combustion stratification study of Partially Premixed Combustion

    NARCIS (Netherlands)

    Izadi Najafabadi, M.; Dam, N.; Somers, B.; Johansson, B.

    2016-01-01

    Relatively high levels of stratification is one of the main advantages of Partially Premixed Combustion (PPC) over the Homogeneous Charge Compression Ignition (HCCI) concept. Fuel stratification smoothens heat release and improves controllability of this kind of combustion. However, the lack of a

  6. Methane combustion over lanthanum-based perovskite mixed oxides

    Energy Technology Data Exchange (ETDEWEB)

    Arandiyan, Hamidreza [New South Wales Univ., Sydney (Australia). School of Chemical Engineering

    2015-11-01

    This book presents current research into the catalytic combustion of methane using perovskite-type oxides (ABO{sub 3}). Catalytic combustion has been developed as a method of promoting efficient combustion with minimum pollutant formation as compared to conventional catalytic combustion. Recent theoretical and experimental studies have recommended that noble metals supported on (ABO{sub 3}) with well-ordered porous networks show promising redox properties. Three-dimensionally ordered macroporous (3DOM) materials with interpenetrated and regular mesoporous systems have recently triggered enormous research activity due to their high surface areas, large pore volumes, uniform pore sizes, low cost, environmental benignity, and good chemical stability. These are all highly relevant in terms of the utilization of natural gas in light of recent catalytic innovations and technological advances. The book is of interest to all researchers active in utilization of natural gas with novel catalysts. The research covered comes from the most important industries and research centers in the field. The book serves not only as a text for researcher into catalytic combustion of methane, 3DOM perovskite mixed oxide, but also explores the field of green technologies by experts in academia and industry. This book will appeal to those interested in research on the environmental impact of combustion, materials and catalysis.

  7. Predicting the combustion kinetics of Chinese coals

    Energy Technology Data Exchange (ETDEWEB)

    Niksa, Stephen [Niksa Energy Associates LLC, Belmont, CA (United States); Fujiwara, Naoki [Idemitsu Kosan Co., Ltd, Chiba (Japan). Coal and Environment Research Lab.

    2013-07-01

    The database on the devolatilization of Chinese coals in the English literature represents coals from all ranks and the major Chinese mines. It was mostly acquired with TGAs. There are sufficient datasets from devices that imposed rapid heating rates to bracket combustor behavior. The domains of heating rate, temperature, pressure, and particle size are either directly relevant to combustion conditions, or close enough to manage with modest extrapolations. Whereas the data on ultimate total yields is sufficient to validate a model for any coal type, more detailed product distributions and char compositions would be desirable. Based on the accurate interpretation of this database, there are few unresolved issues surrounding the applicability of FLASHCHAIN {sup registered} for combustion applications in China. The sub-database on devolatilization under rapid heating conditions represents 34 samples. The predicted yields were within the measurement uncertainties of 4 daf wt. % for 29 of these coals. Among the five ultimate yields that were not accurately predicted, three had measured values less than the proximate volatile matter (PVM), despite the rapid heating rates in the tests. Similarly, the sub-database on devolatilization under slow heating conditions characterizes ultimate devolatilization yields of 30 samples. The predicted yields were within the measurement uncertainties for 22 of these coals. Among the eight that were not accurately predicted, three had measured values that were much lower than the PVM (which is a problem even after accounting for the slow heating rates in the tests) and three were in studies that did not report ultimate analyses for the coals tested. Unfortunately, the database on the combustion behavior of the chars from Chinese coals is insufficient to specify char oxidation kinetics.

  8. Nitrogen Chemistry in Fluidized Bed Combustion of Coal

    DEFF Research Database (Denmark)

    Jensen, Anker Degn

    and reduction by homogeneous and heterogeneous reactions. The data for the estimation of kinetics of the heterogeneous reactions were measured by one of the partners in the project for char and bed material sampled from a pressurized FBC pilot plant burning Kiveton Park coal. Experimental data from the pilot...... plant were used for model verification. The simulations of the NO emission during staged combustion and NH3 injection for NO reduction were in qualitative agreement with the experimental data. A parametric study of the influence of operating conditions on the conversion of fuel-N to NO showed......, the gas interchange coefficient, the bubble size and the bubble rise velocity. The most important combustion parameters were the rate of CO and CH4 combustion and the fraction of CO produced from char combustion. By using a rate of production analysis, the important reactions in the NO model were...

  9. Opportunity's Surroundings on Sol 1798 (Polar)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top. This view is presented as a polar projection with geometric seam correction. The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

  10. Opportunity's Surroundings After Sol 1820 Drive (Polar)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009). This view is presented as a polar projection with geometric seam correction. North is at the top. The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock.

  11. Opportunity's Surroundings on Sol 1798 (Vertical)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top. This view is presented as a vertical projection with geometric seam correction. The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

  12. Opportunity's Surroundings on Sol 1687 (Vertical)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 360-degree view of the rover's surroundings on the 1,687th Martian day, or sol, of its surface mission (Oct. 22, 2008). Opportunity had driven 133 meters (436 feet) that sol, crossing sand ripples up to about 10 centimeters (4 inches) tall. The tracks visible in the foreground are in the east-northeast direction. Opportunity's position on Sol 1687 was about 300 meters southwest of Victoria Crater. The rover was beginning a long trek toward a much larger crater, Endeavour, about 12 kilometers (7 miles) to the southeast. This view is presented as a vertical projection with geometric seam correction.

  13. Opportunity's Surroundings After Sol 1820 Drive (Vertical)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009). This view is presented as a vertical projection with geometric seam correction. North is at the top. The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock.

  14. Opportunity's Surroundings on Sol 1687 (Polar)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 360-degree view of the rover's surroundings on the 1,687th Martian day, or sol, of its surface mission (Oct. 22, 2008). Opportunity had driven 133 meters (436 feet) that sol, crossing sand ripples up to about 10 centimeters (4 inches) tall. The tracks visible in the foreground are in the east-northeast direction. Opportunity's position on Sol 1687 was about 300 meters southwest of Victoria Crater. The rover was beginning a long trek toward a much larger crater, Endeavour, about 12 kilometers (7 miles) to the southeast. This view is presented as a polar projection with geometric seam correction.

  15. Opportunity's Surroundings After Sol 1820 Drive

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009). South is at the center; north at both ends. The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock. This view is presented as a cylindrical projection with geometric seam correction.

  16. Towards Semantic Understanding of Surrounding Vehicular Maneuvers

    DEFF Research Database (Denmark)

    Kristoffersen, Miklas Strøm; Dueholm, Jacob Velling; Satzoda, Ravi K.

    2016-01-01

    This paper proposes the use of multiple low-cost visual sensors to obtain a surround view of the ego-vehicle for semantic understanding. A multi-perspective view will assist the analysis of naturalistic driving studies (NDS), by automating the task of data reduction of the observed sequences...... into events. A user-centric vision-based framework is presented using a vehicle detector and tracker in each separate perspective. Multi-perspective trajectories are estimated and analyzed to extract 14 different events, including potential dangerous behaviors such as overtakes and cut-ins. The system...... is tested on ten sequences of real-world data collected on U. S. highways. The results show the potential use of multiple low-cost visual sensors for semantic understanding around the ego-vehicle....

  17. Lovelock black holes surrounded by quintessence

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Sushant G. [University of KwaZulu-Natal, Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics and Computer Science, Durban (South Africa); Centre for Theoretical Physics, Multidisciplinary Centre for Advanced Research and Studies (MCARS), New Delhi (India); Maharaj, Sunil D.; Baboolal, Dharmanand; Lee, Tae-Hun [University of KwaZulu-Natal, Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics and Computer Science, Durban (South Africa)

    2018-02-15

    Lovelock gravity consisting of the dimensionally continued Euler densities is a natural generalization of general relativity to higher dimensions such that equations of motion are still second order, and the theory is free of ghosts. A scalar field with a positive potential that yields an accelerating universe has been termed quintessence. We present exact black hole solutions in D-dimensional Lovelock gravity surrounded by quintessence matter and also perform a detailed thermodynamical study. Further, we find that the mass, entropy and temperature of the black hole are corrected due to the quintessence background. In particular, we find that a phase transition occurs with a divergence of the heat capacity at the critical horizon radius, and that specific heat becomes positive for r{sub h} < r{sub c} allowing the black hole to become thermodynamically stable. (orig.)

  18. Lovelock black holes surrounded by quintessence

    Science.gov (United States)

    Ghosh, Sushant G.; Maharaj, Sunil D.; Baboolal, Dharmanand; Lee, Tae-Hun

    2018-02-01

    Lovelock gravity consisting of the dimensionally continued Euler densities is a natural generalization of general relativity to higher dimensions such that equations of motion are still second order, and the theory is free of ghosts. A scalar field with a positive potential that yields an accelerating universe has been termed quintessence. We present exact black hole solutions in D-dimensional Lovelock gravity surrounded by quintessence matter and also perform a detailed thermodynamical study. Further, we find that the mass, entropy and temperature of the black hole are corrected due to the quintessence background. In particular, we find that a phase transition occurs with a divergence of the heat capacity at the critical horizon radius, and that specific heat becomes positive for r_h

  19. Heat transfer in heterogeneous propellant combustion systems

    International Nuclear Information System (INIS)

    Brewster, M.Q.

    1992-01-01

    This paper reports that heat transfer plays an important role in several critical areas of heterogeneous, solid-propellant combustion systems. These areas include heat feedback to the propellant surface, heat transfer between burning aluminum droplets and their surroundings, heat transfer to internal insulation systems, and heat transfer to aft-end equipment. Gas conduction dominates heat feedback to the propellant surface in conventional ammonium perchlorate (AP) composite propellants, although particle radiative feedback also plays a significant role in combustion of metalized propellants. Particle radiation plays a dominant role in heat transfer to internal insulation, compared with that of convection. However, conduction by impingement of burning aluminum particles, which has not been extensively studied, may also be significant. Radiative heat loss plays an important role in determining the burning rate of molten aluminum particles due to a highly luminous, oxide particle-laden, detached flame envelope. Radiation by aluminum oxide smoke particles also plays a dominant role in heat transfer from the exhaust plume to aft-end equipment. Uncertainties in aluminum oxide particle-size distribution and optical properties still make it difficult to predict radiative plume heat transfer accurately from first principles

  20. Combustion Stratification for Naphtha from CI Combustion to PPC

    KAUST Repository

    Vallinayagam, R.

    2017-03-28

    This study demonstrates the combustion stratification from conventional compression ignition (CI) combustion to partially premixed combustion (PPC). Experiments are performed in an optical CI engine at a speed of 1200 rpm for diesel and naphtha (RON = 46). The motored pressure at TDC is maintained at 35 bar and fuelMEP is kept constant at 5.1 bar to account for the difference in fuel properties between naphtha and diesel. Single injection strategy is employed and the fuel is injected at a pressure of 800 bar. Photron FASTCAM SA4 that captures in-cylinder combustion at the rate of 10000 frames per second is employed. The captured high speed video is processed to study the combustion homogeneity based on an algorithm reported in previous studies. Starting from late fuel injection timings, combustion stratification is investigated by advancing the fuel injection timings. For late start of injection (SOI), a direct link between SOI and combustion phasing is noticed. At early SOI, combustion phasing depends on both intake air temperature and SOI. In order to match the combustion phasing (CA50) of diesel, the intake air temperature is increased to 90°C for naphtha. The combustion stratification from CI to PPC is also investigated for various level of dilution by displacing oxygen with nitrogen in the intake. The start of combustion (SOC) was delayed with the increase in dilution and to compensate for this, the intake air temperature is increased. The mixture homogeneity is enhanced for higher dilution due to longer ignition delay. The results show that high speed image is initially blue and then turned yellow, indicating soot formation and oxidation. The luminosity of combustion images decreases with early SOI and increased dilution. The images are processed to generate the level of stratification based on the image intensity. The level of stratification is same for diesel and naphtha at various SOI. When O concentration in the intake is decreased to 17.7% and 14

  1. Some Factors Affecting Combustion in an Internal-Combustion Engine

    Science.gov (United States)

    Rothrock, A M; Cohn, Mildred

    1936-01-01

    An investigation of the combustion of gasoline, safety, and diesel fuels was made in the NACA combustion apparatus under conditions of temperature that permitted ignition by spark with direct fuel injection, in spite of the compression ratio of 12.7 employed. The influence of such variables as injection advance angle, jacket temperature, engine speed, and spark position was studied. The most pronounced effect was that an increase in the injection advance angle (beyond a certain minimum value) caused a decrease in the extent and rate of combustion. In almost all cases combustion improved with increased temperature. The results show that at low air temperatures the rates of combustion vary with the volatility of the fuel, but that at high temperatures this relationship does not exist and the rates depend to a greater extent on the chemical nature of the fuel.

  2. Preliminary assessment of combustion modes for internal combustion wave rotors

    Science.gov (United States)

    Nalim, M. Razi

    1995-01-01

    Combustion within the channels of a wave rotor is examined as a means of obtaining pressure gain during heat addition in a gas turbine engine. Several modes of combustion are considered and the factors that determine the applicability of three modes are evaluated in detail; premixed autoignition/detonation, premixed deflagration, and non-premixed compression ignition. The last two will require strong turbulence for completion of combustion in a reasonable time in the wave rotor. The compression/autoignition modes will require inlet temperatures in excess of 1500 R for reliable ignition with most hydrocarbon fuels; otherwise, a supplementary ignition method must be provided. Examples of combustion mode selection are presented for two core engine applications that had been previously designed with equivalent 4-port wave rotor topping cycles using external combustion.

  3. Synthesis and evaluation of ceramic materials for its application in fuel cells in solid state; Sintesis y evaluacion de materiales ceramicos para su aplicacion en celdas de combustible en estado solido

    Energy Technology Data Exchange (ETDEWEB)

    Cortes Escobedo, Claudia Alicia

    2007-09-15

    A study is presented on the Lanthanum Manganite of (LaMnO{sub 3}) with structure perovsquita type and its potential use as cathode in fuel cells. The mecano-sintesis of lanthanum powder manganites is proposed as a method to maximize the defects, since punctual defects in these materials for applications of cathodes in fuel cells are required. Intrinsic precise defects were introduced in the lanthanum manganite mixing lanthanum oxide with manganese oxide (with different numbers of oxidation). In addition, extrinsic defects were introduced doping the of lanthanum manganites with 15 and 20% of strontium in lanthanum sites. A comparison between the final structural properties of the manganites obtained by different processes is presented: a) high energy milling in one pass in a SPEX8000 and thermal treatment, b) milling in two passes by milling of high energy in a SPEX8000D and thermal treatment and c) by thermal activation. A study is presented of the main variables that take part in the mecanosintesis technique, as the volumetric relations between the powders and balls, etc. the relation in weight between dusts and the balls, etc. Experiments of pre-consolidation of synthesized powders took place using vegetal starches of native maize, potatoes, wheat and waxy wheat. The best results were obtained with native maize starch considering the distribution of open micro porosity without losing the shape of the test tubes presented. The test tubes in green were sintered at 1000, 1100 and 1300 degrees Celsius. The largest grain size was obtained in samples processed to 1300 degrees Celsius and a greater open porosity at 1100 degrees Celsius. The measurement results of the electrical conductivity in all the doped samples of LaMnO{sub 3} and without doping were carried out from 70 to 1173 degrees Kelvinand showed values in the rank of 100-25 S/cm. The highest total conductivity was obtained for samples of manganites prepared from MnO with 20% of strontium in lanthanum sites

  4. Path planning during combustion mode switch

    Science.gov (United States)

    Jiang, Li; Ravi, Nikhil

    2015-12-29

    Systems and methods are provided for transitioning between a first combustion mode and a second combustion mode in an internal combustion engine. A current operating point of the engine is identified and a target operating point for the internal combustion engine in the second combustion mode is also determined. A predefined optimized transition operating point is selected from memory. While operating in the first combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion engine to approach the selected optimized transition operating point. When the engine is operating at the selected optimized transition operating point, the combustion mode is switched from the first combustion mode to the second combustion mode. While operating in the second combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion to approach the target operating point.

  5. AIR EMISSIONS FROM SCRAP TIRE COMBUSTION

    Science.gov (United States)

    The report discusses air emissions from two types of scrap tire combustion: uncontrolled and controlled. Uncontrolled sources are open tire fires, which produce many unhealthful products of incomplete combustion and release them directly into the atmosphere. Controlled combustion...

  6. Plasma igniter for internal-combustion engines

    Science.gov (United States)

    Breshears, R. R.; Fitzgerald, D. J.

    1978-01-01

    Hot ionized gas (plasma) ignites air/fuel mixture in internal combustion engines more effectively than spark. Electromagnetic forces propel plasma into combustion zone. Combustion rate is not limited by flame-front speed.

  7. Manifold methods for methane combustion

    Energy Technology Data Exchange (ETDEWEB)

    Yang, B.; Pope, S.B. [Cornell Univ., Ithaca, NY (United States)

    1995-10-01

    Great progresses have been made in combustion research, especially, the computation of laminar flames and the probability density function (PDF) method in turbulent combustion. For one-dimensional laminar flames, by considering the transport mechanism, the detailed chemical kinetic mechanism and the interactions between these two basic processes, today it is a routine matter to calculate flame velocities, extinction, ignition, temperature, and species distributions from the governing equations. Results are in good agreement with those obtained for experiments. However, for turbulent combustion, because of the complexities of turbulent flow, chemical reactions, and the interaction between them, in the foreseeable future, it is impossible to calculate the combustion flow field by directly integrating the basic governing equations. So averaging and modeling are necessary in turbulent combustion studies. Averaging, on one hand, simplifies turbulent combustion calculations, on the other hand, it introduces the infamous closure problems, especially the closure problem with chemical reaction terms. Since in PDF calculations of turbulent combustion, the averages of the chemical reaction terms can be calculated, PDF methods overcome the closure problem with the reaction terms. It has been shown that the PDF method is a most promising method to calculate turbulent combustion. PDF methods have been successfully employed to calculate laboratory turbulent flames: they can predict phenomena such as super equilibrium radical levels, and local extinction. Because of these advantages, PDF methods are becoming used increasingly in industry combustor codes.

  8. Development of sodium droplet combustion analysis methodology using direct numerical simulation in 3-dimensional coordinate (COMET)

    International Nuclear Information System (INIS)

    Okano, Yasushi; Ohira, Hiroaki

    1998-08-01

    In the early stage of sodium leak event of liquid metal fast breeder reactor, LMFBR, liquid sodium flows out from a piping, and ignition and combustion of liquid sodium droplet might occur under certain environmental condition. Compressible forced air flow, diffusion of chemical species, liquid sodium droplet behavior, chemical reactions and thermodynamic properties should be evaluated with considering physical dependence and numerical connection among them for analyzing combustion of sodium liquid droplet. A direct numerical simulation code was developed for numerical analysis of sodium liquid droplet in forced convection air flow. The numerical code named COMET, 'Sodium Droplet COmbustion Analysis METhodology using Direct Numerical Simulation in 3-Dimensional Coordinate'. The extended MAC method was used to calculate compressible forced air flow. Counter diffusion among chemical species is also calculated. Transport models of mass and energy between droplet and surrounding atmospheric air were developed. Equation-solving methods were used for computing multiphase equilibrium between sodium and air. Thermodynamic properties of chemical species were evaluated using dynamic theory of gases. Combustion of single sphere liquid sodium droplet in forced convection, constant velocity, uniform air flow was numerically simulated using COMET. Change of droplet diameter with time was closely agree with d 2 -law of droplet combustion theory. Spatial distributions of combustion rate and heat generation and formation, decomposition and movement of chemical species were analyzed. Quantitative calculations of heat generation and chemical species formation in spray combustion are enabled for various kinds of environmental condition by simulating liquid sodium droplet combustion using COMET. (author)

  9. Combustion & Laser Diagnostics Research Complex (CLDRC)

    Data.gov (United States)

    Federal Laboratory Consortium — Description: The Combustion and Laser Diagnostics Research Complex (CLRDC) supports the experimental and computational study of fundamental combustion phenomena to...

  10. Fiscal 1997 survey report. Subtask 8 (hydrogen utilization worldwide clean energy system technology) (WE-NET) (R and D of hydrogen combustion turbines/development of ultra-high temperature materials); 1997 nendo seika hokokusho. Suiso riyo kokusai clean energy system gijutsu (WE-NET) subtask 8 suiso nensho turbine kenkyu kaihatsu chokoon zairyo no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    For the application to hydrogen combustion turbines, the R and D were continued of heat resistant alloys, ceramic composite materials, and carbonaceous composite materials. In the development of highly efficient super alloy single crystal materials, as to the single crystal alloy (Ni-5.3Al-0.5Ti-6.0Mo-4.8W-6.0Re) and an alloy made by adding 0.15%Si to the above alloy and an alloy made by adding 2.0%Hf to the above alloy, data on high temperature tensile property and creep rupture property were obtained, and it was confirmed that Hf added alloys were excellent in strength. Relating to the development of fiber reinforced ceramics, materials for trial fabrication were fabricated by the CVI method using SiC fiber, and the evaluation test was conducted to obtain the basic data. Besides, the following were carried out: study of coating for heat resistant alloy cooled blades, development of ceramic composite materials, development of ceramic multi-structure materials and analysis of fracture behaviors under the ultra-high composite environment, development of 3D fiber reinforced composite materials, development of technology to evaluate basic properties of ultra-high temperature materials, etc. 46 refs., 217 figs., 43 tabs.

  11. Combustion instability control in the model of combustion chamber

    International Nuclear Information System (INIS)

    Akhmadullin, A N; Ahmethanov, E N; Iovleva, O V; Mitrofanov, G A

    2013-01-01

    An experimental study of the influence of external periodic perturbations on the instability of the combustion chamber in a pulsating combustion. As an external periodic disturbances were used sound waves emitted by the electrodynamics. The purpose of the study was to determine the possibility of using the method of external periodic perturbation to control the combustion instability. The study was conducted on a specially created model of the combustion chamber with a swirl burner in the frequency range from 100 to 1400 Hz. The study found that the method of external periodic perturbations may be used to control combustion instability. Depending on the frequency of the external periodic perturbation is observed as an increase and decrease in the amplitude of the oscillations in the combustion chamber. These effects are due to the mechanisms of synchronous and asynchronous action. External periodic disturbance generated in the path feeding the gaseous fuel, showing the high efficiency of the method of management in terms of energy costs. Power required to initiate periodic disturbances (50 W) is significantly smaller than the thermal capacity of the combustion chamber (100 kW)

  12. Possibility of Coal Combustion Product Conditioning

    Science.gov (United States)

    Błaszczyński, Tomasz Z.; Król, Maciej R.

    2018-03-01

    This paper is focused on properties of materials known as green binders. They can be used to produce aluminium-siliceous concrete and binders known also as geopolymers. Comparing new ecological binders to ordinary cements we can see huge possibility of reducing amount of main greenhouse gas which is emitted to atmosphere by 3 to even 10 times depending of substrate type used to new green material production. Main ecological source of new materials obtaining possibility is to use already available products which are created in coal combustion and steel smelting process. Most of them are already used in many branches of industry. They are mostly civil engineering, chemistry or agriculture. Conducted research was based on less popular in civil engineering fly ash based on lignite combustion. Materials were examine in order to verify possibility of obtaining hardened mortars based of different factors connected with process of geopolymerization, which are temperature, amount of reaction reagent and time of heat treatment. After systematizing the matrices for the basic parameters affecting the strength of the hardened mortars, the influence of the fly ash treatment for increasing the strength was tested.

  13. Opportunity's Surroundings on Sol 1798 (Stereo)

    Science.gov (United States)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11850 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11850 NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this stereo 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top. This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left. The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock. This view is presented as a cylindrical-perspective projection with geometric seam correction.

  14. Opportunity's Surroundings on Sol 1818 (Stereo)

    Science.gov (United States)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11846 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11846 NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends. This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left. The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view. The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock. This view is presented as a cylindrical-perspective projection with geometric seam correction.

  15. Opportunity's Surroundings on Sol 1687 (Stereo)

    Science.gov (United States)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11739 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11739 NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this stereo, 360-degree view of the rover's surroundings on the 1,687th Martian day, or sol, of its surface mission (Oct. 22, 2008). The view appears three-dimensional when viewed through red-blue glasses. Opportunity had driven 133 meters (436 feet) that sol, crossing sand ripples up to about 10 centimeters (4 inches) tall. The tracks visible in the foreground are in the east-northeast direction. Opportunity's position on Sol 1687 was about 300 meters southwest of Victoria Crater. The rover was beginning a long trek toward a much larger crater, Endeavour, about 12 kilometers (7 miles) to the southeast. This panorama combines right-eye and left-eye views presented as cylindrical-perspective projections with geometric seam correction.

  16. Opportunity's Surroundings After Sol 1820 Drive (Stereo)

    Science.gov (United States)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11841 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11841 NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009). This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left. The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock. This view is presented as a cylindrical-perspective projection with geometric seam correction.

  17. The lithosphere-asthenosphere: Italy and surroundings

    International Nuclear Information System (INIS)

    Panza, G.F.; Aoudia, A.; Pontevivo, A.; Chimera, G.; Raykova, R.

    2003-02-01

    The velocity-depth distribution of the lithosphere-asthenosphere in the Italian region and surroundings is imaged, with a lateral resolution of about 100 km, by surface wave velocity tomography and non-linear inversion. Maps of the Moho depth, of the thickness of the lithosphere and of the shear-wave velocities, down to depths of 200 km and more, are constructed. A mantle wedge, identified in the uppermost mantle along the Apennines and the Calabrian Arc, underlies the principal recent volcanoes, and partial melting can be relevant in this part of the uppermost mantle. In Calabria a lithospheric doubling is seen, in connection with the subduction of the Ionian lithosphere. The asthenosphere is shallow in the Southern Tyrrhenian Sea. High velocity bodies, cutting the asthenosphere, outline the Adria-lonian subduction in the Tyrrhenian Sea and the deep-reaching lithospheric root in the Western Alps. Less deep lithospheric roots are seen in the Central Apennines. The lithosphere-asthenosphere properties delineate a differentiation between the northern and the southern sectors of the Adriatic Sea, likely attesting the fragmentation of Adria. (author)

  18. The lithosphere-asthenosphere Italy and surroundings

    CERN Document Server

    Panza, G F; Chimera, G; Pontevivo, A; Raykova, R

    2003-01-01

    The velocity-depth distribution of the lithosphere-asthenosphere in the Italian region and surroundings is imaged, with a lateral resolution of about 100 km, by surface wave velocity tomography and non-linear inversion. Maps of the Moho depth, of the thickness of the lithosphere and of the shear-wave velocities, down to depths of 200 km and more, are constructed. A mantle wedge, identified in the uppermost mantle along the Apennines and the Calabrian Arc, underlies the principal recent volcanoes, and partial melting can be relevant in this part of the uppermost mantle. In Calabria a lithospheric doubling is seen, in connection with the subduction of the Ionian lithosphere. The asthenosphere is shallow in the Southern Tyrrhenian Sea. High velocity bodies, cutting the asthenosphere, outline the Adria-lonian subduction in the Tyrrhenian Sea and the deep-reaching lithospheric root in the Western Alps. Less deep lithospheric roots are seen in the Central Apennines. The lithosphere-asthenosphere properties delineat...

  19. INTERSTELLAR MAGNETIC FIELD SURROUNDING THE HELIOPAUSE

    International Nuclear Information System (INIS)

    Whang, Y. C.

    2010-01-01

    This paper presents a three-dimensional analytical solution, in the limit of very low plasma β-ratio, for the distortion of the interstellar magnetic field surrounding the heliopause. The solution is obtained using a line dipole method that is the integration of point dipole along a semi-infinite line; it represents the magnetic field caused by the presence of the heliopause. The solution allows the variation of the undisturbed magnetic field at any inclination angle. The heliosphere is considered as having blunt-nosed geometry on the upwind side and it asymptotically approaches a cylindrical geometry having an open exit for the continuous outflow of the solar wind on the downwind side. The heliopause is treated as a magnetohydrodynamic tangential discontinuity; the interstellar magnetic field lines at the boundary are tangential to the heliopause. The interstellar magnetic field is substantially distorted due to the presence of the heliopause. The solution shows the draping of the field lines around the heliopause. The magnetic field strength varies substantially near the surface of the heliopause. The effect on the magnetic field due to the presence of the heliopause penetrates very deep into the interstellar space; the depth of penetration is of the same order of magnitude as the scale length of the heliosphere.

  20. Small scale combustion of solid biofuels; Smaaskalig foerbraenning av fasta biobraenslen

    Energy Technology Data Exchange (ETDEWEB)

    2010-12-15

    The purpose of this assignment is to explore the need and the consequences of giving municipalities more power to intervene in the case of individual plants of local heating creates a nuisance in the surrounding areas as high emissions of hazardous air pollutants. The mission does not include an analysis of general instruments for small-scale combustion of biofuels

  1. Space Station Freedom combustion research

    Science.gov (United States)

    Faeth, G. M.

    1992-01-01

    Extended operations in microgravity, on board spacecraft like Space Station Freedom, provide both unusual opportunities and unusual challenges for combustion science. On the one hand, eliminating the intrusion of buoyancy provides a valuable new perspective for fundamental studies of combustion phenomena. On the other hand, however, the absence of buoyancy creates new hazards of fires and explosions that must be understood to assure safe manned space activities. These considerations - and the relevance of combustion science to problems of pollutants, energy utilization, waste incineration, power and propulsion systems, and fire and explosion hazards, among others - provide strong motivation for microgravity combustion research. The intrusion of buoyancy is a greater impediment to fundamental combustion studies than to most other areas of science. Combustion intrinsically heats gases with the resulting buoyant motion at normal gravity either preventing or vastly complicating measurements. Perversely, this limitation is most evident for fundamental laboratory experiments; few practical combustion phenomena are significantly affected by buoyancy. Thus, we have never observed the most fundamental combustion phenomena - laminar premixed and diffusion flames, heterogeneous flames of particles and surfaces, low-speed turbulent flames, etc. - without substantial buoyant disturbances. This precludes rational merging of theory, where buoyancy is of little interest, and experiments, that always are contaminated by buoyancy, which is the traditional path for developing most areas of science. The current microgravity combustion program seeks to rectify this deficiency using both ground-based and space-based facilities, with experiments involving space-based facilities including: laminar premixed flames, soot processes in laminar jet diffusion flames, structure of laminar and turbulent jet diffusion flames, solid surface combustion, one-dimensional smoldering, ignition and flame

  2. Influence of surrounding environment on subcritical crack growth in marble

    Science.gov (United States)

    Nara, Yoshitaka; Kashiwaya, Koki; Nishida, Yuki; , Toshinori, Ii

    2017-06-01

    Understanding subcritical crack growth in rock is essential for determining appropriate measures to ensure the long-term integrity of rock masses surrounding structures and for construction from rock material. In this study, subcritical crack growth in marble was investigated experimentally, focusing on the influence of the surrounding environment on the relationship between the crack velocity and stress intensity factor. The crack velocity increased with increasing temperature and/or relative humidity. In all cases, the crack velocity increased with increasing stress intensity factor. However, for Carrara marble (CM) in air, we observed a region in which the crack velocity still increased with temperature, but the increase in the crack velocity with increasing stress intensity factor was not significant. This is similar to Region II of subcritical crack growth observed in glass in air. Region II in glass is controlled by mass transport to the crack tip. In the case of rock, the transport of water to the crack tip is important. In general, Region II is not observed for subcritical crack growth in rock materials, because rocks contain water. Because the porosity of CM is very low, the amount of water contained in the marble is also very small. Therefore, our results imply that we observed Region II in CM. Because the crack velocity increased in both water and air with increasing temperature and humidity, we concluded that dry conditions at low temperature are desirable for the long-term integrity of a carbonate rock mass. Additionally, mass transport to the crack tip is an important process for subcritical crack growth in rock with low porosity.

  3. Combustible dusts: a serious industrial hazard.

    Science.gov (United States)

    Joseph, Giby

    2007-04-11

    After investigating three fatal explosions in manufacturing plants, the U.S. Chemical Safety and Hazard Investigation Board (CSB) has concluded: The explosive hazard of combustible dust is not well known, and helping industry to understand this hazard is a priority. Prompted by these three incidents in North Carolina, Kentucky and Indiana and the need to increase the hazard awareness, CSB is conducting a study to examine the nature and scope of dust explosion risks in industry and to identify initiatives that may be necessary to more effectively prevent combustible dust fires and explosions. Such initiatives may include regulatory action, voluntary consensus standards, or other measures that could be taken by industry, labor, government, and other parties. A critical task of the dust study is analyzing past incidents to determine the severity of the problem within industry. The analysis is focusing on the number of incidents, injuries and fatalities, industrial sectors affected, and regulatory oversight. This paper presents the preliminary findings from CSBs analysis of combustible dust incidents over the past 25 years. This paper has not been approved by the Board and is published for general informational purposes only. Every effort has been made to accurately present the contents of any Board-approved report mentioned in this paper. Any material in the paper that did not originate in a Board-approved report is solely the responsibility of the authors and does not represent an official finding, conclusion, or position of the Board.

  4. The combustion behavior of large scale lithium titanate battery

    Science.gov (United States)

    Huang, Peifeng; Wang, Qingsong; Li, Ke; Ping, Ping; Sun, Jinhua

    2015-01-01

    Safety problem is always a big obstacle for lithium battery marching to large scale application. However, the knowledge on the battery combustion behavior is limited. To investigate the combustion behavior of large scale lithium battery, three 50 Ah Li(NixCoyMnz)O2/Li4Ti5O12 batteries under different state of charge (SOC) were heated to fire. The flame size variation is depicted to analyze the combustion behavior directly. The mass loss rate, temperature and heat release rate are used to analyze the combustion behavior in reaction way deeply. Based on the phenomenon, the combustion process is divided into three basic stages, even more complicated at higher SOC with sudden smoke flow ejected. The reason is that a phase change occurs in Li(NixCoyMnz)O2 material from layer structure to spinel structure. The critical temperatures of ignition are at 112–121°C on anode tab and 139 to 147°C on upper surface for all cells. But the heating time and combustion time become shorter with the ascending of SOC. The results indicate that the battery fire hazard increases with the SOC. It is analyzed that the internal short and the Li+ distribution are the main causes that lead to the difference. PMID:25586064

  5. FY 1998 annual summary report on International Clean Energy Network Using Hydrogen Conversion (WE-NET) system technology. Subtask 8. Development of hydrogen combustion turbine and ultrahigh-temperature materials; 1998 nendo seika hokokusho. Suiso riyo kokusai clean energy system gijutsu (WE-NET) subtask 8 (suiro nensho turbine no kaihatsu/chokoon zairyo no kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Summarized herein are the materials designs/production and tests/evaluation results of heat-resistant materials, i.e., alloys, ceramic composites and carbon-based composites, which are expected to be applicable to the hydrogen combustion turbines. These have been studied since 1993, and this paper summarizes the overall evaluation results of the phase I program. The intermetallic compound as one of the candidate materials has a high-temperature strength in a range from 1200 to 1400 degrees C by optimizing elements added. However, no prospect is obtained for heat resistance at 1700 degrees C or more for the material not coated or cooled moderately. Each of the other candidate materials tested shows a bright prospect of applicability at the base material and specimen levels. The single-crystal superalloy for hybrid cooling structures has novelty in that it is free of Cr but incorporated with Si and Hf, showing approximately 10 degrees C higher heat-resistant temperature than CMSX-4. CMC and C/C are inherently excellent heat-resistant materials, and are attractive advanced composites, because they are expected to realize no-cooled blades at 1700 degrees C. (NEDO)

  6. Dilute Oxygen Combustion Phase I Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, H.M.; Riley, M.F.; Kobayashi, H.

    1997-10-31

    A novel burner, in which fuel (natural gas) and oxidant (oxygen or air) are separately injected into a furnace, shows promise for achieving very low nitrogen oxide(s) (NOx) emissions for commercial furnace applications. The dilute oxygen combustion (DOC) burner achieves very low NOx through in-furnace dilution of the oxidant stream prior to combustion, resulting in low flame temperatures, thus inhibiting thermal NOx production. The results of a fundamental and applied research effort on the development of the DOC burner are presented. In addition, the results of a market survey detailing the potential commercial impact of the DOC system are disclosed. The fundamental aspects of the burner development project involved examining the flame characteristics of a natural gas turbulent jet in a high-temperature (~1366 K) oxidant (7-27% O2 vol. wet). Specifically, the mass entrainment rate, the flame lift-off height, the velocity field and major species field of the jet were evaluated as a function of surrounding-gas temperature and composition. The measured entrainment rate of the fuel jet decreased with increasing oxygen content in the surrounding high-temperature oxidant, and was well represented by the d+ scaling correlation found in the literature. The measured flame lift-off height decreased with increasing oxygen content and increasing temperature of the surrounding gas. An increase in surrounding-gas oxygen content and/or temperature inhibited the velocity decay within the jet periphery as a function of axial distance as compared to isothermal turbulent jets. However, the velocity measurements were only broadly represented by the d+ scaling correlation. Several DOC burner configurations were tested in a laboratory-scale furnace at a nominal firing rate of 185 kW (~0.63 MMBtu/h). The flue gas composition was recorded as a function of furnace nitrogen content, furnace temperature, burner geometric arrangement, firing rate, and fuel injection velocity. NOx emissions

  7. Dilute oxygen combustion. Phase I report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    A novel burner, in which fuel (natural gas) and oxidant (oxygen or air) are separately injected into a furnace, shows promise for achieving very low nitrogen oxide(s) (NO{sub x}) emissions for commercial furnace applications. The dilute oxygen combustion (DOC) burner achieves very low NO{sub x} through in-furnace dilution of the oxidant stream prior to combustion, resulting in low flame temperatures, thus inhibiting thermal NO{sub x} production. The results of a fundamental and applied research effort on the development of the DOC burner are presented. In addition, the results of a market survey detailing the potential commercial impact of the DOC system are disclosed. The fundamental aspects of the burner development project involved examining the flame characteristics of a natural gas turbulent jet in a high-temperature ({approximately}1366 K) oxidant (7-27% O{sub 2} vol. wet). Specifically, the mass entrainment rate, the flame lift-off height, the velocity field and major species field of the jet were evaluated as a function of surrounding-gas temperature and composition. The measured entrainment rate of the fuel jet decreased with increasing oxygen content in the surrounding high-temperature oxidant, and was well represented by the d{sup +} scaling correlation found in the literature. The measured flame lift-off height decreased with increasing oxygen content and increasing temperature of the surrounding gas. An increase in surrounding-gas oxygen content and/or temperature inhibited the velocity decay within the jet periphery as a function of axial distance as compared to isothermal turbulent jets. However, the velocity measurements were only broadly represented by the d{sup +} scaling correlation. Several DOC burner configurations were tested in a laboratory-scale furnace at a nominal firing rate of 185 kW ({approximately}0.63 MMBtu/h). The flue gas composition was recorded as a function of furnace nitrogen content, furnace temperature, burner geometric

  8. TEM investigations of microstructures of combustion aerosols

    International Nuclear Information System (INIS)

    Marquardt, A.; Hackfort, H.; Borchardt, J.; Schober, T.; Friedrich, J.

    1992-12-01

    In the incineration of organic material, apart from a series of gaseous pollutants, particulate pollutants or combustion aerosols also arise. The latter frequently consist of particles with a solid core of carbon to which a large number of inorganic and organic compounds are attached. These primarily include the polycyclic aromatic hydrocarbons (PAH) and their nitro-derivatives (NPAH), whose mutagenic or carcinogenic effect is known. The invisible particle sizes in the nanometer range, whose retention in the incineration off-gas is not state of the art, are of increasing significance for man and environment. On the one hand, they are deposited almost completely in the human lung. On the other hand, due to their fine dispersity they have along residence time in the atmosphere where they participate in chemical reactions and climatically significant processes. Important insights about the formation process of combustion aerosols are to be expected from the imaging of their microstructures in the transmission electron microscope (TEM). The present contribution describes the development and application of a representative sampling procedure for aerosols from a partial flow of flue gas from a fluidized-bed furnace. The method developed consists of electrically charging aerosol particles in situ and subsequently selectively precipitating them onto a microscope slide in an electric field. TEM studies of aerosol microstructures on the microscope slides revealed that in the combustion of petrol and heating oil under different combustion conditions in principle the same particle structures result, whereas in the incineration of used lubricating oil quite different particle structures were found. Results from the literature on aerosol microstructures in exhaust gases from petrol and diesel engines demonstrate agreement with the results of this study in the basic structure of the particles. (orig.) [de

  9. Understanding community norms surrounding tobacco sales.

    Directory of Open Access Journals (Sweden)

    Patricia A McDaniel

    Full Text Available In the US, denormalizing tobacco use is key to tobacco control; less attention has been paid to denormalizing tobacco sales. However, some localities have placed limits on the number and type of retailers who may sell tobacco, and some retailers have abandoned tobacco sales voluntarily. Understanding community norms surrounding tobacco sales may help accelerate tobacco denormalization.We conducted 15 focus groups with customers of California, New York, and Ohio retailers who had voluntarily discontinued tobacco sales to examine normative assumptions about where cigarettes should or should not be sold, voluntary decisions to discontinue tobacco sales, and government limits on such sales.Groups in all three states generally agreed that grocery stores that sold healthy products should not sell tobacco; California groups saw pharmacies similarly, while this was a minority opinion in the other two states. Convenience stores were regarded as a natural place to sell tobacco. In each state, it was regarded as normal and commendable for some stores to want to stop selling tobacco, although few participants could imagine convenience stores doing so. Views on government's role in setting limits on tobacco sales varied, with California and New York participants generally expressing support for restrictions, and Ohio participants expressing opposition. However, even those who expressed opposition did not approve of tobacco sales in all possible venues. Banning tobacco sales entirely was not yet normative.Limiting the ubiquitous availability of tobacco sales is key to ending the tobacco epidemic. Some limits on tobacco sales appear to be normative from the perspective of community members; it may be possible to shift norms further by problematizing the ubiquitous presence of cigarettes and drawing connections to other products already subject to restrictions.

  10. Understanding community norms surrounding tobacco sales.

    Science.gov (United States)

    McDaniel, Patricia A; Malone, Ruth E

    2014-01-01

    In the US, denormalizing tobacco use is key to tobacco control; less attention has been paid to denormalizing tobacco sales. However, some localities have placed limits on the number and type of retailers who may sell tobacco, and some retailers have abandoned tobacco sales voluntarily. Understanding community norms surrounding tobacco sales may help accelerate tobacco denormalization. We conducted 15 focus groups with customers of California, New York, and Ohio retailers who had voluntarily discontinued tobacco sales to examine normative assumptions about where cigarettes should or should not be sold, voluntary decisions to discontinue tobacco sales, and government limits on such sales. Groups in all three states generally agreed that grocery stores that sold healthy products should not sell tobacco; California groups saw pharmacies similarly, while this was a minority opinion in the other two states. Convenience stores were regarded as a natural place to sell tobacco. In each state, it was regarded as normal and commendable for some stores to want to stop selling tobacco, although few participants could imagine convenience stores doing so. Views on government's role in setting limits on tobacco sales varied, with California and New York participants generally expressing support for restrictions, and Ohio participants expressing opposition. However, even those who expressed opposition did not approve of tobacco sales in all possible venues. Banning tobacco sales entirely was not yet normative. Limiting the ubiquitous availability of tobacco sales is key to ending the tobacco epidemic. Some limits on tobacco sales appear to be normative from the perspective of community members; it may be possible to shift norms further by problematizing the ubiquitous presence of cigarettes and drawing connections to other products already subject to restrictions.

  11. Catalytic Combustion of Gasified Waste

    Energy Technology Data Exchange (ETDEWEB)

    Kusar, Henrik

    2003-09-01

    This thesis concerns catalytic combustion for gas turbine application using a low heating-value (LHV) gas, derived from gasified waste. The main research in catalytic combustion focuses on methane as fuel, but an increasing interest is directed towards catalytic combustion of LHV fuels. This thesis shows that it is possible to catalytically combust a LHV gas and to oxidize fuel-bound nitrogen (NH{sub 3}) directly into N{sub 2} without forming NO{sub x} The first part of the thesis gives a background to the system. It defines waste, shortly describes gasification and more thoroughly catalytic combustion. The second part of the present thesis, paper I, concerns the development and testing of potential catalysts for catalytic combustion of LHV gases. The objective of this work was to investigate the possibility to use a stable metal oxide instead of noble metals as ignition catalyst and at the same time reduce the formation of NO{sub x} In paper II pilot-scale tests were carried out to prove the potential of catalytic combustion using real gasified waste and to compare with the results obtained in laboratory scale using a synthetic gas simulating gasified waste. In paper III, selective catalytic oxidation for decreasing the NO{sub x} formation from fuel-bound nitrogen was examined using two different approaches: fuel-lean and fuel-rich conditions. Finally, the last part of the thesis deals with deactivation of catalysts. The various deactivation processes which may affect high-temperature catalytic combustion are reviewed in paper IV. In paper V the poisoning effect of low amounts of sulfur was studied; various metal oxides as well as supported palladium and platinum catalysts were used as catalysts for combustion of a synthetic gas. In conclusion, with the results obtained in this thesis it would be possible to compose a working catalytic system for gas turbine application using a LHV gas.

  12. Characterization of ultra-fast deposited polycrystalline graphite by a CO{sub 2} laser-assisted combustion-flame method

    Energy Technology Data Exchange (ETDEWEB)

    McKindra, Travis, E-mail: mckindra@mst.edu [Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Patil, Sandeep; O' Keefe, Matthew J. [Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Han Yaoxuan; Ling Hao; Lu Yongfeng [Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588 (United States)

    2009-02-15

    High deposition rate, 750 {mu}m/min, crystalline graphite was deposited on WC substrates by a CO{sub 2} laser-assisted combustion-flame method at laser powers between 300 and 800 W. The structures, which were identified as pillars, were characterized by various methods. The pillars were cylindrical in shape and grew to a size of approximately 3 mm in length and in a few minutes. The laser power did not affect the overall length of the pillar, but caused changes in the physical shape. X-ray and electron diffraction results revealed the pillars to be crystalline graphite regardless of the laser power. Investigation of the pillars by scanning electron microscopy showed two distinct microstructural areas: an inner core of dense material surrounded by an outer shell of lamellar-like material. The core/shell microstructure was unaffected by the level of CO{sub 2} laser power.

  13. Reducing emissions from diesel combustion

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper contains information dealing with engine design to reduce emissions and improve or maintain fuel economy. Topics include: Observation of High Pressure Fuel Spray with Laser Light Sheet Method; Determination of Engine Cylinder Pressures from Crankshaft Speed Fluctuations; Combustion Similarity for Different Size Diesel Engines: Theoretical Prediction and Experimental Results; Prediction of Diesel Engine Particulate Emission During Transient Cycles; Characteristics and Combustibility of Particulate Matter; Dual-Fuel Diesel Engine Using Butane; Measurement of Flame Temperature Distribution in D.I. Diesel Engine with High Pressure Fuel Injection: and Combustion in a Small DI Diesel Engine at Starting

  14. Proceedings of the 2006 Combustion Institute Canadian Section spring technical meeting

    International Nuclear Information System (INIS)

    Devaud, C.; Weckman, E.; Lam, C.; Spike, E.

    2006-01-01

    This conference provided a networking opportunity for academic, government and industrial combustion researchers from across Canada. All aspects of combustion were discussed, particularly those related to new engine technologies that reduce exhaust gas emissions while maintaining performance. Major engine operating and fuelling control parameters that improve combustion efficiency were identified. The conference was divided into several sessions dealing with combustion emissions and pollutants such as soot and particulates; alternative fuels including biofuels and fuel cells; chemical kinetics; droplet and spray combustion; combustion synthesis of materials; detonations, explosions, fires, flammability, flares and incineration; environmental issues and hazard analysis; and, numerical modeling and simulation. The conference featured 61 presentations, of which 39 have been catalogued separately for inclusion in this database

  15. A practical approach in porous medium combustion for domestic application: A review

    Science.gov (United States)

    Ismail, A. K.; Ibrahim, N. H.; Shamsuddin, K. A.; Abdullah, M. Z.; Zubair, M.

    2018-05-01

    Combustion in porous media has been widely studied. Many application involving the combustion of porous media has been reported in various way with most consider on numerical works and industrial application. Besides, recent application of porous medium combustion for domestic is the topic of interest among researchers. In this paper, a review was conducted on the combustion of porous media in term of practical application for domestic consumers. Details on the type of fuel used including bio fuel and their system have been search thoroughly. Most of the system have utilized compressed air system to provide lean combustion in domestic application. Some self-aspirating system of porous medium burner was also reported. The application of new technology such as cogeneration by using thermoelectric cells in tandem with porous medium combustion is also revised according to recent work which have already been published. Besides, the recent advances which include coating of porous material is also considered at the end of this paper.

  16. Method of making metal oxide ceramic powders by using a combustible amino acid compound

    Science.gov (United States)

    Pederson, Larry R.; Chick, Lawrence A.; Exarhos, Gregory J.

    1992-01-01

    This invention is directed to the formation of homogeneous, aqueous precursor mixtures of at least one substantially soluble metal salt and a substantially soluble, combustible co-reactant compound, typically an amino acid. This produces, upon evaporation, a substantially homogeneous intermediate material having a total solids level which would support combustion. The homogeneous intermediate material essentially comprises highly dispersed or solvated metal constituents and the co-reactant compound. The intermediate material is quite flammable. A metal oxide powder results on ignition of the intermediate product which combusts same to produce the product powder.

  17. Control over surrounding rocks deformation of soft floor and whole-coal gateways with trapezoidal supports

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, X.; Li, D.; Shao, Q.; Sun, Y. [Henan Polytechnic University, Jaozuo (China). Dept. of Resource and Material Engineering

    2005-06-01

    The coal seams of Guengcun Coal mine of Yima Coal Group Co. Ltd. are prone to spontaneous combustion. Fully mechanized longwall mining with sublevel caving is used as the mining method. Based on the characteristics of the gateways of the 1301 coal face and of the roof coal seams, the natural equilibrium arch theory was used to design the parameters of 11 mine-type metal supports. Then, in-situ supporting experiments were carried out. The results indicate that under the action of virgin rock stress, the width of broken rocks zone of surrounding rocks is 1.7-2.0 m in the return heading and 1.1-1.3 m in the outgoing headway and their surrounding rocks belong to the IV-type soft rock and the III-type common surrounding rock respectively. Therefore, under the movable abutment pressure, the gateway deformation is serious. At the same time, the accumulated water on gateway floor must be drained in time. These measures were taken in the 1302 and 1304 coal faces in Gengcun colliery, and satisfactory results have been obtained. 8 refs., 3 figs.

  18. Fuel injection apparatus for internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Fujisawa, H; Kobayashi, H; Nagata, S

    1975-01-07

    A fuel injection apparatus for a rapid cut of fuel supply to internal combustion engines during deceleration is described. The fuel cut is achieved by an electromagnetic switch. The number of engine revolutions are determined by the movement of cam shafts, and one of the cam shafts is made of electroconductive and nonconductive materials which generate an intermittent electrical signal to the magnetic switch. The device can cut the fuel in any deceleration condition, therefore it is more advantageous than fuel injection utilizing the intake load variation which can operate only under certain deceleration conditions.

  19. Risk of dust explosions of combustible nanomaterials

    International Nuclear Information System (INIS)

    Dobashi, Ritsu

    2009-01-01

    Nanomaterials have several valuable properties and are widely used for various practical applications. However, safety matters are suspected such as the influence on health and environment, and fire and explosion hazards. To minimize the risk of nanomaterials, appropriate understanding of these hazards is indispensable. Nanoparticles of combustible materials have potential hazard of dust explosion accidents. However, the explosion risk of nanomaterials has not yet been understood adequately because of the lack of data for nanomaterials. In this presentation, the risk of dust explosions of nanomaterials is discussed.

  20. Dust separation on bio mass combustion plants

    OpenAIRE

    Srebrenkoska, Vineta

    2011-01-01

    Biomass is material from vegetation, it can be used as a fuel in various boilers and combustor. The main components: carbon, oxygen and hydrogen but it also contains nitrogen, sulphur, small amounts of chlorides and ash. The main part of the ash comprises: Ca, K, Si, Mg, Mn, Al, Fe, P, Na and Zn. During combustion, various kinds of impurities are generated and some of them we find in the flue gas. Most of these are related to the composition of the biomass: particles from ash, NOx f...

  1. Radiation exposures due to fossil fuel combustion

    Science.gov (United States)

    Beck, Harold L.

    The current consensus regarding the potential radiation exposures resulting from the combustion of fossil fuels is examined. Sources, releases and potential doses to humans are discussed, both for power plants and waste materials. It is concluded that the radiation exposure to most individuals from any pathway is probably insignificant, i.e. only a tiny fraction of the dose received from natural sources in soil and building materials. Any small dose that may result from power-plant emissions will most likely be from inhalation of the small insoluble ash particles from the more poorly controlled plants burning higher than average activity fuel, rather than from direct or indirect ingestion of food grown on contaminated soil. One potentially significant pathway for exposure to humans that requires further evaluation is the effect on indoor external γ-radiation levels resulting from the use of flyash in building materials. The combustion of natural gas in private dwellings is also discussed, and the radiological consequences are concluded to be generally insignificant, except under certain extraordinary circumstances.

  2. Computational Modeling of Turbulent Spray Combustion

    NARCIS (Netherlands)

    Ma, L.

    2016-01-01

    The objective of the research presented in this thesis is development and validation of predictive models or modeling approaches of liquid fuel combustion (spray combustion) in hot-diluted environments, known as flameless combustion or MILD combustion. The goal is to combine good physical insight,

  3. Measures for a quality combustion (combustion chamber exit and downstream); Mesures pour une combustion de qualite (sortie de chambre de combustion et en aval)

    Energy Technology Data Exchange (ETDEWEB)

    Epinat, G. [APAVE Lyonnaise, 69 (France)

    1996-12-31

    After a review of the different pollutants related to the various types of stationary and mobile combustion processes (stoichiometric, reducing and oxidizing combustion), measures and analyses than may be used to ensure the quality and efficiency of combustion processes are reviewed: opacimeters, UV analyzers, etc. The regulation and control equipment for combustion systems are then listed, according to the generator capacity level

  4. Fuels and Combustion | Transportation Research | NREL

    Science.gov (United States)

    Fuels and Combustion Fuels and Combustion This is the March 2015 issue of the Transportation and , combustion strategy, and engine design hold the potential to maximize vehicle energy efficiency and performance of low-carbon fuels in internal combustion engines with a whole-systems approach to fuel chemistry

  5. Fluidized bed and pulverized coal combustion residues for secondary pavements

    International Nuclear Information System (INIS)

    Ghafoori, N.; Diawara, H.; Wang, L.

    2009-01-01

    The United States produced nearly 125 million tons of coal combustion products in 2006. These by-products include fly ash, flue gas desulphurization materials, bottom ash, boiler slag, and other power plant by-products. The expense associated with waste disposal, lack of disposal sites, and significant environmental damage linked with the disposal of coal combustion residues have encouraged innovative utilization strategies such as the fluidized bed combustion (FBC) unit. This paper presented the results of a laboratory investigation that examined the properties of composites developed with different proportions of pre-conditioned FBC spent bed, pulverized coal combustion fly ash, natural fine aggregate, and Portland cement. The purpose of the study was to examine the extent to which the by-product composites could replace currently used materials in secondary roads. The paper presented the research objectives and experimental programs, including matrix constituent and proportions; mixture proportions; and mixing, curing, sampling, and testing. The discussion of results centered around compressive strength and expansion by internal sulfate attack. It was concluded that with proper proportioning, by-products of pulverized and fluidized bed combustion promote binding of sand particles and provide adequate strength under various curing and moisture conditions 4 refs., 6 tabs.

  6. Combustion modeling in waste tanks

    International Nuclear Information System (INIS)

    Mueller, C.; Unal, C.; Travis, J.R.; Forschungszentrum Karlsruhe

    1997-01-01

    This paper has two objectives. The first one is to repeat previous simulations of release and combustion of flammable gases in tank SY-101 at the Hanford reservation with the recently developed code GASFLOW-II. The GASFLOW-II results are compared with the results obtained with the HMS/TRAC code and show good agreement, especially for non-combustion cases. For combustion GASFLOW-II predicts a steeper pressure rise than HMS/TRAC. The second objective is to describe a so-called induction parameter model which was developed and implemented into GASFLOW-II and reassess previous calculations of Bureau of Mines experiments for hydrogen-air combustion. The pressure time history improves compared with the one-step model, and the time rate of pressure change is much closer to the experimental data

  7. Environmental sensing and combustion diagnostics

    International Nuclear Information System (INIS)

    Santoleri, J.J.

    1991-01-01

    This book contains proceedings of Environmental Sensing and Combustion Diagnostics. Topics covered include: Incineration Systems Applications, Permitting, And Monitoring Overview; Infrared Techniques Applied to Incineration Systems; Continuous Emission Monitors; Analyzers and Sensors for Process Control And Environmental Monitoring

  8. 75 FR 3881 - Combustible Dust

    Science.gov (United States)

    2010-01-25

    ..., rubber, drugs, dried blood, dyes, certain textiles, and metals (such as aluminum and magnesium..., furniture manufacturing, metal processing, fabricated metal products and machinery manufacturing, pesticide... standard that will comprehensively address the fire and explosion hazards of combustible dust. The Agency...

  9. Particulate and gaseous emissions from residential biomass combustion

    International Nuclear Information System (INIS)

    Boman, Christoffer

    2005-04-01

    different stoves were determined with variations in fuel, appliance and operational properties. The emissions of PICs as well as PM tot from wood combustion were in general shown to be considerably higher compared to pellets combustion. PAH tot emissions were determined in the range of 1,300-220,000 μg/MJ for wood stoves and 2-300 μg/MJ for pellet stoves with phenantrene, fluoranthene and pyrene generally found as major PAHs. The PM emissions from present residential appliances was found to consist of significant but varying fractions of PICs, with emissions in the range 35-350 mg/MJ for wood stoves compared to 15-45 mg/MJ for pellet stoves. Accordingly, the use of up-graded biomass fuels, combusted under continuous and controlled conditions give advantageous combustion conditions compared to traditional batch wise firing of wood logs. The importance of high temperature in well mixed isothermal conditions was further illustrated during pellets combustion to obtain complete combustion with almost a total depletion of PICs. Fine (100-300 nm) particles dominated in all studied cases the PM with 80-95% as PM 1 . Beside varying fractions of carbonaceous material, the fine PM consisted of inorganic volatilized ash elements, mainly found as KCl, K 3 Na(SO 4 ) 2 and K 2 SO 4 with mass concentrations at 15-20 mg/MJ during complete combustion. The importance of the behavior of alkali elements for the ash transformation and fine particle formation processes was further shown, since the stability, distributions and compositions also directly control the degree of volatilization. In addition to the alkali metals, zinc was found as an important element in fine particles from residential biomass combustion. Finally, the behaviour of volatile trace elements, e.g. Zn and Cd, during pellets production and combustion were studied. A significant enrichment in the pellet fuel during the drying process was determined. The magnitude and importance of the enrichment was, however, relative small

  10. Modeling of microgravity combustion experiments

    Science.gov (United States)

    Buckmaster, John

    1995-01-01

    This program started in February 1991, and is designed to improve our understanding of basic combustion phenomena by the modeling of various configurations undergoing experimental study by others. Results through 1992 were reported in the second workshop. Work since that time has examined the following topics: Flame-balls; Intrinsic and acoustic instabilities in multiphase mixtures; Radiation effects in premixed combustion; Smouldering, both forward and reverse, as well as two dimensional smoulder.

  11. Quantifying emissions from spontaneous combustion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-09-01

    Spontaneous combustion can be a significant problem in the coal industry, not only due to the obvious safety hazard and the potential loss of valuable assets, but also with respect to the release of gaseous pollutants, especially CO2, from uncontrolled coal fires. This report reviews methodologies for measuring emissions from spontaneous combustion and discusses methods for quantifying, estimating and accounting for the purpose of preparing emission inventories.

  12. Development of Explosive Ripper with Two-Stage Combustion

    Science.gov (United States)

    1974-10-01

    inch pipe duct work, the width of this duct proved to be detrimental in marginally rippable material; the duct, instead of the penetrator tip, was...marginally rippable rock. ID. Operating Requirements 2. Fuel The two-stage combustion device is designed to operate using S A 42. the same diesel

  13. Drying wood waste with a pulse combustion dryer

    Energy Technology Data Exchange (ETDEWEB)

    Buchkowski, A.G. [Spectrum Engineering Corp., Ltd., Peterborough, Ontario (Canada); Kitchen, J.A. [John A. Kitchen, Ltd., Hastings, Ontario (Canada)

    1993-12-31

    There is a vast amount of wood waste available to be used as an alternate fuel if its moisture could be reduced efficiently. Tests have been conducted to assess an industrial dryer using pulse combustion as a heating source for drying wood waste; specifically sawdust and pulverized wet hog fuel. Pulse combustion offers the advantage of high heat transfer, efficient combustion, and low NO{sub x} emissions. The material is injected into the exhaust gases in the tailpipe of the combustor which uses natural gas or propane as a fuel. The turbulence created by the pulsations enhance the drying process by reducing the boundary layer thicknesses. The materials is further dried in a rotary drum. The material has been dried without scorching or burning in tests where the inlet moisture content has been as high as 60% on a wet basis. The outlet moisture contents achieved have typically been 10%. Analysis of the test data and cost estimates of the equipment indicate that the pulse combustion drying system is at least comparable to existing systems in terms of operating costs, and offers very significant savings in capital costs. Testing with various other materials such as wood pulp, sludges and peat is continuing to further assess the equipment`s performance.

  14. Fuel accountability and control at Combustion Engineering, Inc

    International Nuclear Information System (INIS)

    Kersteen, G.C.

    1978-01-01

    Combustion Engineering, Inc. has recently developed and installed an automated data collection, data processing system for the accounting and control of special nuclear material. The system uses a variety of data collection techniques and some relatively new data processing ideas. The next few pages describe the Fuel Accountability and Control System

  15. Detonation and combustion of explosives: A selected bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Dobratz, B. [comp.

    1998-08-01

    This bibliography consists of citations pertinent to the subjects of combustion and detonation of energetic materials, especially, but not exclusively, of secondary solid high explosives. These references were selected from abstracting sources, conference proceedings, reviews, and also individual works. The entries are arranged alphabetically by first author and numbered sequentially. A keyword index is appended.

  16. Thermal effects from the release of selenium from a coal combustion during high-temperature processing: a review.

    Science.gov (United States)

    Hu, Jianjun; Sun, Qiang; He, Huan

    2018-04-11

    The release of selenium (Se) during coal combustion can have serious impacts on the ecological environment and human health. Therefore, it is very important to study the factors that concern the release of Se from coal combustion. In this paper, the characteristics of the release of Se from coal combustion, pyrolysis, and gasification of different coal species under different conditions are studied. The results show that the amount of released Se increases at higher combustion temperatures. There are obvious increases in the amount of released Se especially in the temperature range of 300 to 800 °C. In addition, more Se is released from the coal gasification than coal combustion process, but more Se is released from coal combustion than pyrolysis. The type of coal, rate of heating, type of mineral ions, and combustion atmosphere have different effects on the released percentage of Se. Therefore, having a good understanding of the factors that surround the release of Se during coal combustion, and then establishing the combustion conditions can reduce the impacts of this toxic element to humans and the environment.

  17. Mathematical Model of Piston Ring Sealing in Combustion Engine

    Directory of Open Access Journals (Sweden)

    Koszałka Grzegorz

    2015-01-01

    Full Text Available This paper presents a mathematical model of piston-rings-cylinder sealing (TPC of a combustion engine. The developed model is an itegrated model of gas flow through gaps in TPC unit, displacements and twisting motions of piston rings in ring grooves as well as generation of oil film between ring face surfaces and cylinder liner. Thermal deformations and wear of TPC unit elements as well as heat exchange between flowing gas and surrounding walls, were taken into account in the model. The paper contains descriptions of: assumptions used for developing the model, the model itself, its numerical solution as well as its computer application for carrying out simulation tests.

  18. Bioenergy originating from biomass combustion in a fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Crujeira, T.; Gulyurtlu, I.; Lopes, H.; Abelha, P.; Cabrita, I. [INETI/DEECA, Lisboa (Portugal)

    2008-07-01

    Bioenergy could significantly contribute to reducing and controlling greenhouse emissions (GHG) and to replace fossil fuels in large power plants. Although the use of biomass, originating from forests, could be beneficial, particularly in preventing fires, there are obstacles to achieve a sustainable supply chain of biomass in most European countries. In addition, there are also technical barriers as requirements of biomass combustion may differ from those of coal, which could mean significant retrofitting of existing installations. The combustion behaviour of different biomass materials were studied on a pilot fluidised bed combustor, equipped with two cyclones for particulate matter removal. The gaseous pollutants leaving the stack were sampled under isokinetic conditions for particulate matter, chlorine compounds, heavy metals and dioxins and furans (PCDD/F). The results obtained indicated that the combustion of these materials did not present any operational problem, although for temperatures above 800{sup o}C, bed agglomeration could be observed for all biomass materials studied. Most of the combustion of biomass, contrary to what is observed for coal, takes place in the riser where the temperature was as much as 150{sup o}C above that of the bed. Stable combustion conditions were achieved as well as high combustion efficiency. When compared with the emissions of bituminous coal, the most used fossil fuel, the emissions of CO and SO2 were found to be lower and NOx emissions were similar to those of coal. HCl and PCDD/F could be considerable with biomasses containing high chlorine levels, as in the case of straw. It was observed that the nature of ash could give rise serious operating problems.

  19. Techniques de combustion Combustin Techniques

    Directory of Open Access Journals (Sweden)

    Perthuis E.

    2006-11-01

    Full Text Available L'efficacité d'un processus de chauffage par flamme est étroitement liée à la maîtrise des techniques de combustion. Le brûleur, organe essentiel de l'équipement de chauffe, doit d'une part assurer une combustion complète pour utiliser au mieux l'énergie potentielle du combustible et, d'autre part, provoquer dans le foyer les conditions aérodynamiques les plus propices oux transferts de chaleur. En s'appuyant sur les études expérimentales effectuées à la Fondation de Recherches Internationales sur les Flammes (FRIF, au Groupe d'Étude des Flammes de Gaz Naturel (GEFGN et à l'Institut Français du Pétrole (IFP et sur des réalisations industrielles, on présente les propriétés essentielles des flammes de diffusion aux combustibles liquides et gazeux obtenues avec ou sans mise en rotation des fluides, et leurs répercussions sur les transferts thermiques. La recherche des températures de combustion élevées conduit à envisager la marche à excès d'air réduit, le réchauffage de l'air ou son enrichissement à l'oxygène. Par quelques exemples, on évoque l'influence de ces paramètres d'exploitation sur l'économie possible en combustible. The efficiency of a flame heating process is closely linked ta the mastery of, combustion techniques. The burner, an essential element in any heating equipment, must provide complete combustion sa as to make optimum use of the potential energy in the fuel while, at the same time, creating the most suitable conditions for heat transfers in the combustion chamber. On the basis of experimental research performed by FRIF, GEFGN and IFP and of industrial achievements, this article describesthe essential properties of diffusion flames fed by liquid and gaseous fuels and produced with or without fluid swirling, and the effects of such flames on heat transfers. The search for high combustion temperatures means that consideration must be given to operating with reduced excess air, heating the air or

  20. Hydrogen utilization international clean energy system technology (WE-NET). Subtask 8. Research and development of hydrogen combustion turbines (development of ultra-high temperature materials); Suiso riyo kokusai clean energy system (WE-NET). Subtask 8. Suiso nensho turbine no kenkyu kaihatsu chokoon zairyo no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The paper described the result of the fiscal 1996 development of ultra-high temperature materials for parts of hydrogen combustion turbines, as part of the hydrogen utilization technology, which have excellent environmental protectivity and remarkably high efficiency. By the optimized solution heat treatment of monocrystal alloy developed in the previous fiscal year, obtained was strength property the same as the existing super alloys. As to FRC, pore size and strength property of SiC organic hybrid were made clear. ODS alloy cooling blades and heat insulation coating were studied, and YSZ was found to be most excellent as coating material. Concerning intermetallic compounds, the applicability to ultra-high temperatures up to 1700degC was not obtained. For improvement of heat resistance and environment resistance, adopted were highly compacting SiC matrix and BN coatings. Al2O3 was excellent in long-time stability. In the 1600degC steam corrosion test on multiplex structural materials with Al2O3 as surface material, chemical stability was confirmed. Three-dimensional woven fiber reinforced composite materials of C/C{center_dot}CMC were trially produced by changing the fiber orientation, and improvement in ultra-high temperature thermal shock resistance was confirmed. A study was made of spot observation of the specimen surface by laser microscope, and development was conducted of a temperature measuring method with no influence of radiant heat. 44 refs., 250 figs., 40 tabs.

  1. Evaluación de la eficiencia de remoción de material particulado y dióxido de azufre (so2) en un lavador tipo venturi para una caldera que emplea carbón como combustible

    OpenAIRE

    Jiménez Riaño, Quelver Yesid

    2012-01-01

    El aporte de las emisiones industriales a la contaminación del aire de Bogotá es significativo y, dentro de las industrias, aquellas que usan carbón como fuente de combustible para la generación de vapor en calderas son las que mayor impacto negativo tiene en la calidad del aire de la ciudad. En este trabajo se llevó a cabo la evaluación de las variables de operación de un sistema de control de emisiones atmosféricas para una caldera industrial a carbón. Se diseño, construyó y puso en marcha ...

  2. On the transition to the normal phase for superconductors surrounded by normal conductors

    DEFF Research Database (Denmark)

    Fournais, Søren; Kachmar, Ayman

    2009-01-01

    For a cylindrical superconductor surrounded by a normal material, we discuss transition to the normal phase of stable, locally stable and critical configurations. Associated with those phase transitions, we define critical magnetic fields and we provide a sufficient condition for which those...

  3. HERCULES Advanced Combustion Concepts Test Facility: Spray/Combustion Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, K. [Eidgenoessische Technische Hochschule (ETH), Labor fuer Aerothermochemie und Verbrennungssysteme, Zuerich (Switzerland)

    2004-07-01

    This yearly report for 2004 on behalf of the Swiss Federal Office of Energy (SFOE) at the Laboratory for Aero-thermochemistry and Combustion Systems at the Federal Institute of Technology ETH in Zurich, Switzerland, presents a review of work being done within the framework of HERCULES (High Efficiency R and D on Combustion with Ultra Low Emissions for Ships) - the international R and D project concerning new technologies for ships' diesels. The work involves the use and augmentation of simulation models. These are to be validated using experimental data. The report deals with the development of an experimental set-up that will simulate combustion in large two-stroke diesel engines and allow the generation of reference data. The main element of the test apparatus is a spray / combustion chamber with extensive possibilities for optical observation under variable flow conditions. The results of first simulations confirm concepts and shall help in further work on the project. The potential offered by high-speed camera systems was tested using the institute's existing HTDZ combustion chamber. Further work to be done is reviewed.

  4. Jet plume injection and combustion system for internal combustion engines

    Science.gov (United States)

    Oppenheim, Antoni K.; Maxson, James A.; Hensinger, David M.

    1993-01-01

    An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure.

  5. Pilas de combustible de membrana polimérica

    OpenAIRE

    Asensio, Juan Antonio

    2011-01-01

    En aquest treball revisem breument les piles de combustible polimèriques (PEM) basades en membranes d’intercanvi protònic i que constitueixen la tecnologia idònia de piles de combustible de baixa temperatura, i per tant les més adequades per a aplicació en transport. Revisarem els materials que les componen però també els desenvolupaments necessaris per a la seva implantació definitiva en un mercat inclement amb les tecnologies cares, per netes que siguin. En este trabajo revisamos breveme...

  6. Importance of small-scale wood combustion for the air quality at Lycksele and Vaexjoe

    International Nuclear Information System (INIS)

    Johansson, C.; Hansson, H.C.; Stroem, Johan; Hedberg, Emma; Olivares, Gustavo; Karlsson, Hans; Wideqvist, Ulla

    2005-02-01

    15% of the PM in Lycksele whereas these compounds represented almost 70% of PM in Vaexjoe. Assuming that most of the metals were in the form of oxides the total metal oxide concentration constituted around 10% at both sites. Source receptor modelling using the PMF model (Positive Multivariate Factorization) was performed based on 17 different elements analysed by PIXE. Six different sources were identified. In Lycksele the dominating source contribution was from wood burning (∼60%). This source was identified using potassium, rubidium and zinc. Long-range transport contributed with around 20% and local road dust with 6-10%. The LRT was identified mainly by sulphur. Essentially all sulphur was assigned to this source by the PMF model, with only 1% due to wood burning. Road dust was identified by the occurrence of iron, manganese and titanium. The concentrations of levoglucosan correlated strongly with the wood combustion source as calculated by the PMF model based on the elements. According to this correlation around 17% of the particle mass due to wood combustion would be levoglucosan. This was then compared with measured levoglucosan fractions in wood combustion in the laboratory. Unfortunately these laboratory measurements showed that the levoglucosan fraction varied from 0.3% to 22% of the total PM emitted. The variability could not be explained by different combustion conditions. This makes it very uncertain to use levoglucosan as a quantitative tracer of wood combustion. The alternative, to use the potassium elemental concentrations, works well for Forsdala (Lycksele) where wood burning is the dominating source for potassium. In Teleborg (Vaexjoe), crustal material and road dust also contribute to the potassium elemental concentrations. Since potassium is found in wood smoke mainly in the form of various water-soluble potassium salts, an (ion chromatography) analysis of only the water-soluble potassium would be a superior tracer for wood smoke. The results

  7. Characteristics of combustion products: a review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Chan, M.K.W.; Mishima, J.

    1983-07-01

    To determine the effects of fires in nuclear-fuel-cycle facilities, Pacific Northwest Laboratory (PNL) has surveyed the literature to gather data on the characteristics of combustion products. This report discusses the theories of the origin of combustion with an emphasis on the behavior of the combustible materials commonly found in nuclear-fuel-cycle facilities. Data that can be used to calculate particulate generation rate, size, distribution, and concentration are included. Examples are given to illustrate the application of this data to quantitatively predict both the mass and heat generated from fires. As the final result of this review, information gaps are identified that should be filled for fire-accident analyses in fuel-cycle facilities. 29 figures, 32 tables.

  8. Characteristics of combustion products: a review of the literature

    International Nuclear Information System (INIS)

    Chan, M.K.W.; Mishima, J.

    1983-07-01

    To determine the effects of fires in nuclear-fuel-cycle facilities, Pacific Northwest Laboratory (PNL) has surveyed the literature to gather data on the characteristics of combustion products. This report discusses the theories of the origin of combustion with an emphasis on the behavior of the combustible materials commonly found in nuclear-fuel-cycle facilities. Data that can be used to calculate particulate generation rate, size, distribution, and concentration are included. Examples are given to illustrate the application of this data to quantitatively predict both the mass and heat generated from fires. As the final result of this review, information gaps are identified that should be filled for fire-accident analyses in fuel-cycle facilities. 29 figures, 32 tables

  9. Hydrothermal processing of radioactive combustible waste

    International Nuclear Information System (INIS)

    Worl, L.A.; Buelow, S.J.; Harradine, D.; Le, L.; Padilla, D.D.; Roberts, J.H.

    1998-01-01

    Hydrothermal processing has been demonstrated for the treatment of radioactive combustible materials for the US Department of Energy. A hydrothermal processing system was designed, built and tested for operation in a plutonium glovebox. Presented here are results from the study of the hydrothermal oxidation of plutonium and americium contaminated organic wastes. Experiments show the destruction of the organic component to CO 2 and H 2 O, with 30 wt.% H 2 O 2 as an oxidant, at 540 C and 46.2 MPa. The majority of the actinide component forms insoluble products that are easily separated by filtration. A titanium liner in the reactor and heat exchanger provide corrosion resistance for the oxidation of chlorinated organics. The treatment of solid material is accomplished by particle size reduction and the addition of a viscosity enhancing agent to generate a homogeneous pumpable mixture

  10. Characterisation of ashes produced by co-combustion of recovered fuels and peat

    Energy Technology Data Exchange (ETDEWEB)

    Frankenhaeuser, M.; Zevenhoven, R. [Borealis Polymers Oy, Porvoo (Finland); Skrifvars, B.J. [Aabo Akademi, Turku (Finland); Orjala, M. [VTT Energy, Espoo (Finland); Peltola, K. [Foster Wheeler Energy (Finland)

    1996-12-01

    Source separation of combustible materials from household or municipal solid waste yields a raw material for the production of Packaging Derived Fuel (PDF). This fuel can substitute the traditional fuels in heat and power generation and is also called recycled fuel. Co-combustion of these types of fuels with coal has been studied in several LIEKKI-projects and the results have been both technically and environmentally favourable. (author)

  11. Gaseous emissions during concurrent combustion of biomass and non-recyclable municipal solid waste

    Directory of Open Access Journals (Sweden)

    Oakey John

    2011-02-01

    Full Text Available Abstract Background Biomass and municipal solid waste offer sustainable sources of energy; for example to meet heat and electricity demand in the form of combined cooling, heat and power. Combustion of biomass has a lesser impact than solid fossil fuels (e.g. coal upon gas pollutant emissions, whilst energy recovery from municipal solid waste is a beneficial component of an integrated, sustainable waste management programme. Concurrent combustion of these fuels using a fluidised bed combustor may be a successful method of overcoming some of the disadvantages of biomass (high fuel supply and distribution costs, combustion characteristics and characteristics of municipal solid waste (heterogeneous content, conflict with materials recycling. It should be considered that combustion of municipal solid waste may be a financially attractive disposal route if a 'gate fee' value exists for accepting waste for combustion, which will reduce the net cost of utilising relatively more expensive biomass fuels. Results Emissions of nitrogen monoxide and sulphur dioxide for combustion of biomass are suppressed after substitution of biomass for municipal solid waste materials as the input fuel mixture. Interactions between these and other pollutants such as hydrogen chloride, nitrous oxide and carbon monoxide indicate complex, competing reactions occur between intermediates of these compounds to determine final resultant emissions. Conclusions Fluidised bed concurrent combustion is an appropriate technique to exploit biomass and municipal solid waste resources, without the use of fossil fuels. The addition of municipal solid waste to biomass combustion has the effect of reducing emissions of some gaseous pollutants.

  12. Gaseous emissions during concurrent combustion of biomass and non-recyclable municipal solid waste.

    Science.gov (United States)

    Laryea-Goldsmith, René; Oakey, John; Simms, Nigel J

    2011-02-01

    Biomass and municipal solid waste offer sustainable sources of energy; for example to meet heat and electricity demand in the form of combined cooling, heat and power. Combustion of biomass has a lesser impact than solid fossil fuels (e.g. coal) upon gas pollutant emissions, whilst energy recovery from municipal solid waste is a beneficial component of an integrated, sustainable waste management programme. Concurrent combustion of these fuels using a fluidised bed combustor may be a successful method of overcoming some of the disadvantages of biomass (high fuel supply and distribution costs, combustion characteristics) and characteristics of municipal solid waste (heterogeneous content, conflict with materials recycling). It should be considered that combustion of municipal solid waste may be a financially attractive disposal route if a 'gate fee' value exists for accepting waste for combustion, which will reduce the net cost of utilising relatively more expensive biomass fuels. Emissions of nitrogen monoxide and sulphur dioxide for combustion of biomass are suppressed after substitution of biomass for municipal solid waste materials as the input fuel mixture. Interactions between these and other pollutants such as hydrogen chloride, nitrous oxide and carbon monoxide indicate complex, competing reactions occur between intermediates of these compounds to determine final resultant emissions. Fluidised bed concurrent combustion is an appropriate technique to exploit biomass and municipal solid waste resources, without the use of fossil fuels. The addition of municipal solid waste to biomass combustion has the effect of reducing emissions of some gaseous pollutants.

  13. NOx emissions from the underfeed combustion of coal and biomass

    International Nuclear Information System (INIS)

    Purvis, M.R.I.; Tadulan, E.L.; Tariq, A.S.

    2000-01-01

    Underfeed stokers have an inherent ability to minimise smoke emissions, thus providing environmental benefits in the combustion of solid fuels, such as biomass materials, which have a high volatile matter content. An evaluation of this attribute requires comparisons of the performance of combustion equipment using these fuels against reference data for coals. However, the recent literature is virtually devoid of studies of coal combustion in underfeed stokers and, in particular, information on nitrogen oxide emissions. In the UK, this reflects a lack of commercial interest in small-scale coal firing due to the wide availability of inexpensive gas and oil fuels. An experimental investigation has been carried out into the combustion of bituminous coal, anthracite and a 50:50 blend by mass of anthracite and oak wood chips on a modified commercial underfeed stoker. The intention was to obtain operational experiences in burning the fuels and reference data for nitrogen oxide emissions. Problems in the combustion of the fuels are described and related to the determination of nitrogen oxide emission values found under optimised plant conditions. These values, expressed at 6% O 2 , were 265 ppm for bituminous coal, 90 ppm for anthracite and 106 ppm for the anthracite/wood chip blend. (Author)

  14. Decommissioning Combustible Waste Treatment using Oxygen-Enriched Incinerator

    Energy Technology Data Exchange (ETDEWEB)

    Min, Byungyoun; Lee, Yoonji; Yun, Gyoungsu; Lee, Kiwon; Moon, Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The aim of the paper is current status of treatment for the decommissioning combustible waste in KAERI and for the purpose of the volume reduction and clearance for decommissioning combustible wastes generated by the decommissioning projects. The incineration technology has been selected for the treatment of combustible wastes. About 34 tons of decommissioning combustible waste has been treated using Oxygen Enriched incineration. Temperature, pressure of major components, stack gas concentration, i. e., SOx, NOx, CO, CO{sub 2} and HCl, and the residual oxygen were measured. Measured major parameters during normal operation were sustained on a stable status within a criteria operation condition. Oxygen enriched air, 22vol. % (dry basis) was used for stable incineration. The volume reduction ratio has achieved about 1/117. The incineration with decommissioning radioactive combustible waste is possible with moderate oxygen enrichment of 22 vol.% (dry basis) into the supply air. The incineration facility operated quite smoothly through the analysis major critical parameters of off-gas. The pressure, off-gas flow and temperature of major components remained constant within the range specified. The measures gases and particulate materials in stack were considerably below the regulatory limits. The achieved volume reduction ratio through incineration is about 1/117.

  15. Using X-ray methods to evaluate the combustion sulfur minerals and graphitic carbon in coals and ashes

    International Nuclear Information System (INIS)

    Wertz, D.L.; Collins, L.W.

    1988-01-01

    Coals are complex mixtures of vastly different materials whose combustion kinetics may well exhibit symbiotic effects. Although the sulfur oxide gases produced during the combustion of coals may have a variety of sources, they are frequently caused by the thermal degradation of inorganic minerals to produce ''acid rain''. Since many of the minerals involved either as reactants or products in coal combustion produce well defined x-ray power diffraction (XRPD) patterns, the fate of these minerals may be followed by measuring the XRPD patterns of combustion products. Coal 1368P, a coal with an unusually high pyrite (FeS/sub 2/) fraction, has been the subject materials in our investigations of the fate of the inorganic minerals during combustion. These studies include measuring the fate of pyrite and of graphitic carbon in coal 1368P under varying combustion conditions. The results discussed in this paper were obtained by standard XRPD methods

  16. Characterisation of wood combustion ashes

    DEFF Research Database (Denmark)

    Maresca, Alberto

    The combustion of wood chips and wood pellets for the production of renewable energy in Denmark increased from 5.7 PJ to 16 PJ during the period 2000-2015, and further increases are expected to occur within the coming years. In 2012, about 22,300 tonnes of wood ashes were generated in Denmark....... Currently, these ashes are mainly landfilled, despite Danish legislation allowing their application onto forest and agricultural soils for fertilising and/or liming purposes. During this PhD work, 16 wood ash samples generated at ten different Danish combustion plants were collected and characterised...... for their composition and leaching properties. Despite the relatively large variations in the contents of nutrients and trace metals, the overall levels were comparable to typical ranges reported in the literature for other wood combustion ashes, as well as with regards to leaching. In general, the composition...

  17. Novel Active Combustion Control Valve

    Science.gov (United States)

    Caspermeyer, Matt

    2014-01-01

    This project presents an innovative solution for active combustion control. Relative to the state of the art, this concept provides frequency modulation (greater than 1,000 Hz) in combination with high-amplitude modulation (in excess of 30 percent flow) and can be adapted to a large range of fuel injector sizes. Existing valves often have low flow modulation strength. To achieve higher flow modulation requires excessively large valves or too much electrical power to be practical. This active combustion control valve (ACCV) has high-frequency and -amplitude modulation, consumes low electrical power, is closely coupled with the fuel injector for modulation strength, and is practical in size and weight. By mitigating combustion instabilities at higher frequencies than have been previously achieved (approximately 1,000 Hz), this new technology enables gas turbines to run at operating points that produce lower emissions and higher performance.

  18. Chemical-looping combustion - status of development

    Energy Technology Data Exchange (ETDEWEB)

    Lyngfelt, Anders; Johansson, Marcus; Mattisson, Tobias

    2008-05-15

    Chemical-looping combustion (CLC) is a combustion technology with inherent separation of the greenhouse gas CO{sub 2}. The technique involves the use of a metal oxide as an oxygen carrier which transfers oxygen from combustion air to the fuel, and hence a direct contact between air and fuel is avoided. Two inter-connected fluidized beds, a fuel reactor and an air reactor, are used in the process. In the fuel reactor, the metal oxide is reduced by the reaction with the fuel and in the air reactor; the reduced metal oxide is oxidized with air. The outlet gas from the fuel reactor consists of CO{sub 2} and H{sub 2}O, and almost pure stream of CO{sub 2} is obtained when water is condensed. Considerable research has been conducted on CLC in the last years with respect to oxygen carrier development, reactor design, system efficiencies and prototype testing. In 2002 the process was a paper concept, albeit with some important but limited laboratory work on oxygen carrier particles. Today more than 600 materials have been tested and the technique has been successfully demonstrated in chemical-looping combustors in the size range 0.3 - 50 kW, using different types of oxygen carriers based on the metals Ni, Co, Fe, Cu and Mn. The total time of operational experience is more than a thousand hours. From these tests it can be established that almost complete conversion of the fuel can be obtained and 100% CO{sub 2} capture is possible. Most work so far has been focused on gaseous fuels, but the direct application to solid fuels is also being studied. Moreover, the same principle of oxygen transfer is used in chemical-looping reforming (CLR), which involves technologies to produce hydrogen with inherent CO{sub 2} capture. This paper presents an overview of the research performed on CLC and CLR highlights the current status of the technology

  19. How A Black Hole Lights Up Its Surroundings

    Science.gov (United States)

    Kohler, Susanna

    2017-10-01

    How do the supermassive black holes that live at the centers of galaxies influence their environments? New observations of a distant active galaxy offer clues about this interaction.Signs of CoevolutionPlot demonstrating the m-sigma relation, the empirical correlation between the stellar velocity dispersion of a galactic bulge and the mass of the supermassive black hole at its center. [Msigma]We know that the centers of active galaxies host supermassive black holes with masses of millions to billions of suns. One mystery surrounding these beasts is that they are observed to evolve simultaneously with their host galaxies for instance, an empirical relationship is seen between the growth of a black hole and the growth of its host galaxys bulge. This suggests that there must be a feedback mechanism through which the evolution of a black hole is linked to that of its host galaxy.One proposed source of this coupling is the powerful jets emitted from the poles of these supermassive black holes. These jets are thought to be produced as some of the material accreting onto the black hole is flung out, confined by surrounding gas and magnetic fields. Because the jets of hot gas and radiation extend outward through the host galaxy, they provide a means for the black hole to influence the gas and dust of its surroundings.In our current model of a radio-loud active galactic nuclei,a region of hot, ionized gas the narrow-line region lies beyond the sphere of influence of the supermassive black hole. [C.M. Urry and P. Padovani]Clues in the Narrow-Line RegionThe region of gas thought to sit just outside of the black holes sphere of influence (at a distance of perhaps a thousand to a few thousand light-years) is known as the narrow line region so named because we observe narrow emission lines from this gas. Given its hot, ionized state, this gas must somehow be being pummeled with energy. In the canonical picture, radiation from the black hole heats the gas directly in a process

  20. Chemical Absorption Materials

    DEFF Research Database (Denmark)

    Thomsen, Kaj

    2011-01-01

    Chemical absorption materials that potentially can be used for post combustion carbon dioxide capture are discussed. They fall into five groups, alkanolamines, alkali carbonates, ammonia, amino acid salts, and ionic liquids. The chemistry of the materials is discussed and advantages and drawbacks...

  1. Combustion instability modeling and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, R.J.; Yang, V.; Santavicca, D.A. [Pennsylvania State Univ., University Park, PA (United States); Sheppard, E.J. [Tuskeggee Univ., Tuskegee, AL (United States). Dept. of Aerospace Engineering

    1995-12-31

    It is well known that the two key elements for achieving low emissions and high performance in a gas turbine combustor are to simultaneously establish (1) a lean combustion zone for maintaining low NO{sub x} emissions and (2) rapid mixing for good ignition and flame stability. However, these requirements, when coupled with the short combustor lengths used to limit the residence time for NO formation typical of advanced gas turbine combustors, can lead to problems regarding unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions, as well as the occurrence of combustion instabilities. The concurrent development of suitable analytical and numerical models that are validated with experimental studies is important for achieving this objective. A major benefit of the present research will be to provide for the first time an experimentally verified model of emissions and performance of gas turbine combustors. The present study represents a coordinated effort between industry, government and academia to investigate gas turbine combustion dynamics. Specific study areas include development of advanced diagnostics, definition of controlling phenomena, advancement of analytical and numerical modeling capabilities, and assessment of the current status of our ability to apply these tools to practical gas turbine combustors. The present work involves four tasks which address, respectively, (1) the development of a fiber-optic probe for fuel-air ratio measurements, (2) the study of combustion instability using laser-based diagnostics in a high pressure, high temperature flow reactor, (3) the development of analytical and numerical modeling capabilities for describing combustion instability which will be validated against experimental data, and (4) the preparation of a literature survey and establishment of a data base on practical experience with combustion instability.

  2. Findings on pollutant formation in wood and chip board combustion. Erkenntnisse zur Schadstoffbildung bei der Verbrennung von Holz und Spanplatten

    Energy Technology Data Exchange (ETDEWEB)

    Marutzky, R.

    1991-10-01

    Combustion experiments were carried out using wood and several types of chip boards with binders on the basis of urea, melamine and phenol formaldehyde resins, polyureas, and PVC. The combustion process was observed, and the flue gas constituents in case of incomplete combustion were analyzed. The origins of the various organic and inorganic materials were discussed taking account of the results of pyrolysis experiments. (orig.).

  3. Improvement of fuel combustion technologies

    Energy Technology Data Exchange (ETDEWEB)

    Tumanovskii, A.G.; Babii, V.I.; Enyakin, Y.P.; Kotler, V.R.; Ryabov, G.V.; Verbovetskii, E.K.; Nadyrov, I.I. [All-Russian Thermal Engineering Institute, Moscow (Russian Federation)

    1996-07-01

    The main problems encountered in the further development of fuel combustion technologies at thermal power stations in Russia are considered. Experience is generalized and results are presented on the efficiency with which nitrogen oxide emissions are reduced by means of technological methods when burning natural gas, fuel oil, and coal. The problems that arise in the introduction of new combustion technologies and in using more promising grades of coal are considered. The results studies are presented that show that low grade Russian coals can be burnt in circulating fluidized bed boilers. 14 refs., 5 figs., 4 tabs.

  4. Chemical kinetics and combustion modeling

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.A. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    The goal of this program is to gain qualitative insight into how pollutants are formed in combustion systems and to develop quantitative mathematical models to predict their formation rates. The approach is an integrated one, combining low-pressure flame experiments, chemical kinetics modeling, theory, and kinetics experiments to gain as clear a picture as possible of the process in question. These efforts are focused on problems involved with the nitrogen chemistry of combustion systems and on the formation of soot and PAH in flames.

  5. HIV behavioural surveillance among refugees and surrounding host ...

    African Journals Online (AJOL)

    We used a standardised behavioural surveillance survey (BSS), modified to be directly relevant to populations in conflict and post-conflict settings as well as to their surrounding host populations, to survey the populations of a refugee settlement in south-western Uganda and its surrounding area. Two-stage probability ...

  6. Investigation of the readout electronics of DELPHI surround muon chamber

    International Nuclear Information System (INIS)

    Khovanskij, N.; Krumshtejn, Z.; Ol'shevskij, A.; Sadovskij, A.; Sedykh, Yu.; Molnar, J.; Sicho, P.; Tomsa, Z.

    1995-01-01

    The characteristics of the readout electronics of the DELPHI surround muon chambers with various AMPLEX chips (AMPLEX 16 and AMPLEX-SICAL) are presented. This electronics is studied in a cosmic rays test of the real surround muon chamber model. 4 refs., 6 figs., 1 tab

  7. Materiais usados na constituição dos principais componentes de células a combustível de óxido sólido Materials used in the manufacture of the main components of solid oxide fuel cells

    Directory of Open Access Journals (Sweden)

    A. C. Nascimento

    2009-03-01

    Full Text Available As células a combustível de óxido sólido (SOFC são dispositivos capazes de gerar energia elétrica com alta eficiência e baixa emissão de poluentes. As altas temperaturas de operação dessas células (600 a 1000 °C são benéficas no sentido de possibilitar a reforma in situ do combustível utilizado, bem como sua aplicação em sistemas de co-geração de energia, aumentando sua eficiência teórica total que pode chegar entre 80 e 85%. Entretanto, essas altas temperaturas, o contato direto entre materiais de constituições químicas diferentes e a utilização de gases redutores e oxidantes, são alguns dos fatores que impõem severas restrições aos materiais usados na preparação de seus principais componentes. O presente artigo tem como objetivo revisar o desenvolvimento do estado da arte, com relação aos materiais de ânodo, cátodo, eletrólito, interconectores e selantes, usados em SOFCs. Os requisitos necessários para o bom funcionamento de cada componente e os materiais que melhor se adequam aos mesmos são descritos. As vantagens e desvantagens dos principais materiais encontrados na literatura são também comentadas e comparadas.Solid oxide fuel cells (SOFC are devices capable to generate electricity with high efficiency and low emission of pollutants. The high operation temperatures of these batteries (600 to 1000 °C are advantageous, making possible the reform of the fuel used in situ as well as its application in systems for cogeneration of energy, increasing its total efficiency up to values between 80 and 85%. However, these high temperatures require severe restrictions on the materials used in the preparation of their main components. This paper aims to review the state of the art of the developed material as anode material, cathode, electrolyte, interconnects and seals, to be used in SOFCs. The requirements for a good operation of each component and the materials that best fit their specific need are described

  8. Application of the FIRST Combustion model to Spray Combustion

    NARCIS (Netherlands)

    de Jager, B.; Kok, Jacobus B.W.

    2004-01-01

    Liquid fuel is of interest to apply to gas turbines. The large advantage is that liquids are easily storable as compared to gaseous fuels. Disadvantage is that liquid fuel has to be sprayed, vaporized and mixed with air. Combustion occurs at some stage of mixing and ignition. Depending on the

  9. Development of a Premixed Combustion Capability for Scramjet Combustion Experiments

    Science.gov (United States)

    Rockwell, Robert D.; Goyne, Christopher P.; Rice, Brian E.; Chelliah, Harsha; McDaniel, James C.; Edwards, Jack R.; Cantu, Luca M. L.; Gallo, Emanuela C. A.; Cutler, Andrew D.; Danehy, Paul M.

    2015-01-01

    Hypersonic air-breathing engines rely on scramjet combustion processes, which involve high speed, compressible, and highly turbulent flows. The combustion environment and the turbulent flames at the heart of these engines are difficult to simulate and study in the laboratory under well controlled conditions. Typically, wind-tunnel testing is performed that more closely approximates engine testing rather than a careful investigation of the underlying physics that drives the combustion process. The experiments described in this paper, along with companion data sets being developed separately, aim to isolate the chemical kinetic effects from the fuel-air mixing process in a dual-mode scramjet combustion environment. A unique fuel injection approach is taken that produces a nearly uniform fuel-air mixture at the entrance to the combustor. This approach relies on the precombustion shock train upstream of the dual-mode scramjet combustor. A stable ethylene flame anchored on a cavity flameholder with a uniformly mixed combustor inflow has been achieved in these experiments allowing numerous companion studies involving coherent anti-Stokes Raman scattering (CARS), particle image velocimetry (PIV), and planar laser induced fluorescence (PLIF) to be performed.

  10. Stimulus size dependence of hue changes induced by chromatic surrounds.

    Science.gov (United States)

    Kellner, Christian Johannes; Wachtler, Thomas

    2016-03-01

    A chromatic surround induces a change in the perceived hue of a stimulus. This shift in hue depends on the chromatic difference between the stimulus and the surround. We investigated how chromatic induction varies with stimulus size and whether the size dependence depends on the surround hue. Subjects performed asymmetric matching of color stimuli with different sizes in surrounds of different chromaticities. Generally, induced hue shifts decreased with increasing stimulus size. This decrease was quantitatively different for different surround hues. However, when size effects were normalized to an overall induction strength, the chromatic specificity was largely reduced. The separability of inducer chromaticity and stimulus size suggests that these effects are mediated by different neural mechanisms.

  11. Up-date on cyclone combustion and cyclone boilers

    Energy Technology Data Exchange (ETDEWEB)

    Carmo, Felipe Alfaia do; Nogueira, Manoel Fernandes Martins; Rocha, Rodrigo Carnera Castro da; Gazel, Hussein Felix; Martins, Diego Henrique dos Reis [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Campus Universitario Jose da Silveira Netto], E-mails: mfmn@ufpa.br, mfmn@ufpa.br

    2010-07-01

    The boiler concept has been around for more than 70 years, and there are many types available. Boilers provide steam or hot water for industrial and commercial use. The Federal University of Para (UFPA) through the research group EBMA (Energy,Biomass and Environment) has been developing cyclonic furnace with a water wall, a boiler, aiming to use regional timbers (sawdust) and agro-industries residues as fuel to produce steam to be used in industrial processes as well as in power generation,. The use of cyclonic combustion for burning waste instead of burning in a fixed bed is mainly due to two factors efficiency improvement causing a more compact boiler and less risk of explosion, since their process does not generate an accumulation of volatile. Present state-of-art for commercial cyclone boilers has as set up a cyclone combustor with two combustion chambers, in fluid communication, where there ducts for supplying air and fuel directly into the first chamber and for forming a cyclonic flow pattern and a heat exchanger surrounding the second chamber for keeping low combustion temperature in both chambers. This paper shows the results of a literature review about design, construction and operation of cyclonic boilers using solid, liquid or gaseous fuel. This information has been used for the design of a cyclone boiler to be constructed at UFPA for research purposes and its basic concept is presented at the end of this article. (author)

  12. Interactive wood combustion for botanical tree models

    KAUST Repository

    Pirk, Sö ren; Jarząbek, Michał; Hadrich, Torsten; Michels, Dominik L.; Palubicki, Wojciech

    2017-01-01

    We present a novel method for the combustion of botanical tree models. Tree models are represented as connected particles for the branching structure and a polygonal surface mesh for the combustion. Each particle stores biological and physical

  13. Free Energy and Internal Combustion Engine Cycles

    OpenAIRE

    Harris, William D.

    2012-01-01

    The performance of one type (Carnot) of Internal Combustion Engine (ICE) cycle is analyzed within the framework of thermodynamic free energies. ICE performance is different from that of an External Combustion Engine (ECE) which is dictated by Carnot's rule.

  14. Scramjet Combustion Stability Behavior Modeling, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — A recent breakthrough in combustion stability analysis (UCDS) offers the potential to predict the combustion stability of a scramjet. This capability is very...

  15. Scramjet Combustion Stability Behavior Modeling, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A recent breakthrough in combustion stability analysis (UCDS) offers the means to accurately predict the combustion stability of a scramjet. This capability is very...

  16. Publication sites productive uses of combustion ash

    Science.gov (United States)

    Publication Sites Productive Uses of Combustion Ash For more information contact: e:mail: Public waste combustion ash in landfills. The new technology brief describes recent studies where ash was used

  17. Combustion Research Facility | A Department of Energy Office of Science

    Science.gov (United States)

    Collaborative Research Facility Back to Sandia National Laboratory Homepage Combustion Research Search the CRF Combustion Chemistry Flame Chemistry Research.Combustion_Chemistry.Flame_Chemistry Theory and Modeling Theory and Modeling Combustion Kinetics High Pressure Chemistry Chemistry of Autoignition

  18. Fuel Combustion and Engine Performance | Transportation Research | NREL

    Science.gov (United States)

    Fuel Combustion and Engine Performance Fuel Combustion and Engine Performance Photo of a gasoline emissions in advanced engine technologies. Photo by Dennis Schroeder, NREL NREL's combustion research and combustion and engine research activities include: Developing experimental and simulation research platforms

  19. A novel device for processing radioactive combustibles

    International Nuclear Information System (INIS)

    Phelan, P.F.; Thompson, T.K.

    1991-01-01

    Los Alamos National Laboratory is assisting EG ampersand G Rocky Flats, Colorado, with the development of a special incinerator for wastes contaminated with plutonium, a radioactive element. This paper describes one conceptual design that was developed by T.K. Thompson, Inc., under contract to Los Alamos National Laboratory. The design is a tentative proposal that tries to address the many constraints that are peculiar to this project. It has not been endorsed or accepted by EG ampersand G Rocky Flats, and it is subject to revision. Nevertheless, it is noteworthy because of the novel concepts it embodies. Before examining the design itself, it is instructive to understand the constraints imposed by safety and operational concerns. There are three main requirements related to safety: There may be no emissions of radioactive material either to the atmosphere or into the building that houses the incinerator. The outer surfaces of the combustion chamber must be kept below 140oF so that the lead-lined rubber gloves will not melt if the operator reaches inside the glovebox while the incinerator is hot. The combustion chambers and other locations where plutonium-containing ash could accumulate must be designed in such a way that it would be impossible for a critically accident to occur. 3 figs

  20. Volatiles and char combustion rates of demineralised lignite and wood blends

    International Nuclear Information System (INIS)

    Yilgin, Melek; Pehlivan, Dursun

    2009-01-01

    Today, much interest is given to the utilisation of materials of plant origin as substitutions of fossil fuels in meeting energy needs to reduce the level of atmospheric pollutant emissions and global warming threat, and emphasis has been placed on the co-combustion of coal and biomass. In this study, volatiles and char combustion behaviour of the fuel pellets composed from demineralised lignite and poplar wood sawdust, were investigated in a cylindrical wire mesh basket placed in a preheated tube furnace. The results have shown that ignition times of the pellets decreased with the burning temperature and shortened further due to demineralisation of lignite. Volatiles combustion rates of the samples did not correlate well with combustion times. However, they can be correlated with their respective proximate volatile matter contents. Char burnout times decreased with increasing combustion rates and correlated well with the respective proximate fixed carbon contents of the samples. Deviations were more considerable in the case of rate data. (author)

  1. Natural Ores as Oxygen Carriers in Chemical Looping Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Hanjing; Siriwardane, Ranjani; Simonyi, Thomas; Poston, James

    2013-08-01

    Chemical looping combustion (CLC) is a combustion technology that utilizes oxygen from oxygen carriers (OC), such as metal oxides, instead of air to combust fuels. The use of natural minerals as oxygen carriers has advantages, such as lower cost and availability. Eight materials, based on copper or iron oxides, were selected for screening tests of CLC processes using coal and methane as fuels. Thermogravimetric experiments and bench-scale fixed-bed reactor tests were conducted to investigate the oxygen transfer capacity, reaction kinetics, and stability during cyclic reduction/oxidation reaction. Most natural minerals showed lower combustion capacity than pure CuO/Fe{sub 2}O{sub 3} due to low-concentrations of active oxide species in minerals. In coal CLC, chryscolla (Cu-based), magnetite, and limonite (Fe-based) demonstrated better reaction performances than other materials. The addition of steam improved the coal CLC performance when using natural ores because of the steam gasification of coal and the subsequent reaction of gaseous fuels with active oxide species in the natural ores. In methane CLC, chryscolla, hematite, and limonite demonstrated excellent reactivity and stability in 50-cycle thermogravimetric analysis tests. Fe{sub 2}O{sub 3}-based ores possess greater oxygen utilization but require an activation period before achieving full performance in methane CLC. Particle agglomeration issues associated with the application of natural ores in CLC processes were also studied by scanning electron microscopy (SEM).

  2. High Frequency Combustion Instabilities of LOx/CH4 Spray Flames in Rocket Engine Combustion Chambers

    NARCIS (Netherlands)

    Sliphorst, M.

    2011-01-01

    Ever since the early stages of space transportation in the 1940’s, and the related liquid propellant rocket engine development, combustion instability has been a major issue. High frequency combustion instability (HFCI) is the interaction between combustion and the acoustic field in the combustion

  3. Chemical reactor for converting a first material into a second material

    Science.gov (United States)

    Kong, Peter C

    2012-10-16

    A chemical reactor and method for converting a first material into a second material is disclosed and wherein the chemical reactor is provided with a feed stream of a first material which is to be converted into a second material; and wherein the first material is combusted in the chemical reactor to produce a combustion flame, and a resulting gas; and an electrical arc is provided which is passed through or superimposed upon the combustion flame and the resulting gas to facilitate the production of the second material.

  4. Thermochemical Modeling and Experimental Validation of Wood Pyrolysis Occurring During Pre-ignition Combustion

    Science.gov (United States)

    Fawaz, M.; Lautenberger, C.; Bond, T. C.

    2017-12-01

    The use of wood as a solid fuel for cooking and heating is associated with high particle emission which largely contribute to the dispersion of particulate matter (PM) in the atmosphere. The majority of those particles are released during the "pre-ignition" phase, i.e., before flaming of the wood occurs. In this work, we investigate the factors that influence the emission of PM during pre-ignition and lead to high particle emission to the atmosphere. During this combustion phase, at elevated temperature, pyrolysis is responsible for wood degradation and the production of gaseous materials that travel and exit the wood. We model the thermal degradation using Gpyro, an open source finite volume method numerical model to simulate heat, mass, and momentum transfer in the wood. In our analysis, we study factors that vary during combustion and that influence emission of PM: wood sample size and boundary conditions. In a fire the boundary conditions represent the thermal energy a piece of wood receives from the surrounding in the form of heat flux. We find that heat transfer is the limiting process governing the production and transport of gas from the wood, and that the amount of emitted PM is dependent on the size of the wood. The dependence of heat transfer from the boundaries on PM emission becomes more important with increasing wood log size. The model shows that a small log of wood (6cm by 2cm) emits close values of total mass of gas at low and high heat fluxes. For a large log of wood (20cm by 5cm) the total mass of gas emitted increases by 30% between low and high heat flux. We validate the model results with a controlled-temperature reactor that accommodates centimeter scale wood samples. The size of the wood used, indicates the abundance of wood in the region where wood is used a solid fuel. Understanding those factors will allow for defining conditions that result in reducing particle emissions during combustion.

  5. Facile one-pot transformation using structure-guided combustion waves of micro-nanostructured β-Bi2O3 to α-Bi2O3@C and analysis of electrochemical capacitance

    Science.gov (United States)

    Hwang, Hayoung; Shin, Jung-ho; Lee, Kang Yeol; Choi, Wonjoon

    2018-01-01

    Precise phase-transformation can facilitate control of the properties of various materials, while an organic coating surrounding inorganic materials can yield useful characteristics. Herein, we demonstrate facile, selective manipulation of micro-nanostructured bismuth oxide (Bi2O3) for phase transformation from microflower-like β-Bi2O3 to micropill-like α-Bi2O3, with carbon-coating layer deposition, using structure-guided combustion waves (SGCWs). Microflower-like β-Bi2O3 are synthesized as core materials and nitrocellulose is coated on their surfaces for the formation of core-shell hybrid structures of Bi2O3 and chemical fuel. The SGCWs, which propagate along the core-material and fuel interfaces, apply high thermal energy (550-600 °C) and deposit incompletely combusted carbonaceous fuel on the microflower-like β-Bi2O3 to enable transformation to α-phase and carbon-coating-layer synthesis. SGCW-induced improvements to the electrochemical characteristics of the developed micropill-like α-Bi2O3@C, compared with the microflower-like β-Bi2O3, are investigated. The enhanced stability from the α-phase Bi2O3 and micropill-like structures during charge-discharge cycling improves the specific capacitance, while the carbon-coating layers facilitate increased electrical conductivity. SGCW-based methods exhibit high potential for selective phase manipulation and synthesis of carbon coatings surrounding micro-nanomaterials. They constitute a low-cost, fast, large-scale process for metal oxides, ceramics, and hybrid materials, implemented through control of the processing parameters by tuning the temperature, chemical fuel, and ambient conditions.

  6. Leaching from biomass combustion ash

    DEFF Research Database (Denmark)

    Maresca, Alberto; Astrup, Thomas Fruergaard

    2014-01-01

    The use of biomass combustion ashes for fertilizing and liming purposes has been widely addressed in scientific literature. Nevertheless, the content of potentially toxic compounds raises concerns for a possible contamination of the soil. During this study five ash samples generated at four...

  7. An incinerator for combustable radwastes

    International Nuclear Information System (INIS)

    Li Jingquan; Jiang Yun; Zhang Yinsheng; Chen Boling; Zhang Shihang

    1989-01-01

    An incinerator has been built up in Shanghai. In this paper, the devices of the incinerator, main parameters of the process, and the results of non-radioactive waste and simulated radwaste combustion tests were contributed. That provides reference information for radwaste treatment with incineration process

  8. 75 FR 32142 - Combustible Dust

    Science.gov (United States)

    2010-06-07

    .... Contact Mat Chibbaro, P.E., Fire Protection Engineer, Office of Safety Systems, OSHA Directorate of..., and metals (such as aluminum and magnesium). Industries that may have combustible dust hazards include..., chemical manufacturing, textile manufacturing, furniture manufacturing, metal processing, fabricated metal...

  9. Sulfur Chemistry in Combustion II

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Kiil, Søren

    2000-01-01

    Several options are available to control the emission of SO2 from combustion processes. One possibility is to use a cleaner technology, i.e. fuel switching from oil and coal to natural gas or biomass, or to desulphurize coal and oil. Another possibility is to change to a different technology...

  10. Multi-zone modelling of PCCI combustion

    NARCIS (Netherlands)

    Egüz, U.; Somers, L.M.T.; Leermakers, C.A.J.; Goey, de L.P.H.

    2011-01-01

    Early Direct Injection Premixed Charge Compression Ignition (EDI PCCI) combustion is a promising concept for the diesel combustion. Although EDI PCCI assures very low soot and NO xemission levels, the injection is uncoupled from combustion, which narrows down the operating conditions. The main

  11. Method and device for diagnosing and controlling combustion instabilities in internal combustion engines operating in or transitioning to homogeneous charge combustion ignition mode

    Science.gov (United States)

    Wagner, Robert M [Knoxville, TN; Daw, Charles S [Knoxville, TN; Green, Johney B [Knoxville, TN; Edwards, Kevin D [Knoxville, TN

    2008-10-07

    This invention is a method of achieving stable, optimal mixtures of HCCI and SI in practical gasoline internal combustion engines comprising the steps of: characterizing the combustion process based on combustion process measurements, determining the ratio of conventional and HCCI combustion, determining the trajectory (sequence) of states for consecutive combustion processes, and determining subsequent combustion process modifications using said information to steer the engine combustion toward desired behavior.

  12. Parameter studies to determine sensitivity of slug impact loads to properties of core surrounding structures

    International Nuclear Information System (INIS)

    Gvildys, J.

    1985-01-01

    A sensitivity study of the HCDA slug impact response of fast reactor primary containment to properties of core surrounding structures was performed. Parameters such as the strength of the radial shield material, mass, void, and compressibility properties of the gas plenum material, mass of core material, and mass and compressibility properties of the coolant were used as variables to determine the magnitude of the slug impact loads. The response of the reactor primary containment and the partition of energy were also given. A study was also performed using water as coolant to study the difference in slug impact loads

  13. Environmental optimisation of waste combustion

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Robert [AaF Energikonsult, Stockholm (Sweden); Berge, Niclas; Stroemberg, Birgitta [TPS Termiska Processer AB, Nykoeping (Sweden)

    2000-12-01

    The regulations concerning waste combustion evolve through R and D and a strive to get better and common regulations for the European countries. This study discusses if these rules of today concerning oxygen concentration, minimum temperature and residence time in the furnace and the use of stand-by burners are needed, are possible to monitor, are the optimum from an environmental point of view or could be improved. No evidence from well controlled laboratory experiments validate that 850 deg C in 6 % oxygen content in general is the best lower limit. A lower excess air level increase the temperature, which has a significant effect on the destruction of hydrocarbons, favourably increases the residence time, increases the thermal efficiency and the efficiency of the precipitators. Low oxygen content is also necessary to achieve low NO{sub x}-emissions. The conclusion is that the demands on the accuracy of the measurement devices and methods are too high, if they are to be used inside the furnace to control the combustion process. The big problem is however to find representative locations to measure temperature, oxygen content and residence time in the furnace. Another major problem is that the monitoring of the operation conditions today do not secure a good combustion. It can lead to a false security. The reason is that it is very hard to find boilers without stratifications. These stratifications (stream lines) has each a different history of residence time, mixing time, oxygen and combustible gas levels and temperature, when they reach the convection area. The combustion result is the sum of all these different histories. The hydrocarbons emission is in general not produced at a steady level. Small clouds of unburnt hydrocarbons travels along the stream lines showing up as peaks on a THC measurement device. High amplitude peaks has a tendency to contain higher ratio of heavy hydrocarbons than lower peaks. The good correlation between some easily detected

  14. Changes in unique hues induced by chromatic surrounds.

    Science.gov (United States)

    Klauke, Susanne; Wachtler, Thomas

    2016-03-01

    A chromatic surround can have a strong influence on the perceived hue of a stimulus. We investigated whether chromatic induction has similar effects on the perception of colors that appear pure and unmixed (unique red, green, blue, and yellow) as on other colors. Subjects performed unique hue settings of stimuli in isoluminant surrounds of different chromaticities. Compared with the settings in a neutral gray surround, unique hue settings altered systematically with chromatic surrounds. The amount of induced hue shift depended on the difference between stimulus and surround hues, and was similar for unique hue settings as for settings of nonunique hues. Intraindividual variability in unique hue settings was roughly twice as high as for settings obtained in asymmetric matching experiments, which may reflect the presence of a reference stimulus in the matching task. Variabilities were also larger with chromatic surrounds than with neutral gray surrounds, for both unique hue settings and matching of nonunique hues. The results suggest that the neural representations underlying unique hue percepts are influenced by the same neural processing mechanisms as the percepts of other colors.

  15. Combustor nozzle for a fuel-flexible combustion system

    Science.gov (United States)

    Haynes, Joel Meier [Niskayuna, NY; Mosbacher, David Matthew [Cohoes, NY; Janssen, Jonathan Sebastian [Troy, NY; Iyer, Venkatraman Ananthakrishnan [Mason, OH

    2011-03-22

    A combustor nozzle is provided. The combustor nozzle includes a first fuel system configured to introduce a syngas fuel into a combustion chamber to enable lean premixed combustion within the combustion chamber and a second fuel system configured to introduce the syngas fuel, or a hydrocarbon fuel, or diluents, or combinations thereof into the combustion chamber to enable diffusion combustion within the combustion chamber.

  16. Ash quality and environmental quality assurance system in co-combustion - Co-combustion of forest industry waste

    International Nuclear Information System (INIS)

    Laine-Ylijoki, J.; Wahlstroem, M.

    2000-01-01

    The environmental acceptability and possible utilization of co-combustion ashes will have a significant influence on the wider use of co-combustion in the future. At present the correlation between currently used fuels, their mixture ratios, and quality variations in ashes are not known, which complicates the assessment of possible utilization and environmental acceptability of co-combustion ashes. The composition of ashes has also been found to vary significantly. Effective utilization requires that process variations to alter ash composition and quality variations are known in advance. The aim of the research was to characterize the fly ash from co- combustion of peat, wood and biological paper mill sludge produced under different fuel loadings, especially with and without sludge addition, ant to identify critical parameters influencing on the ash composition. The variations in the leaching properties of ashes collected daily were followed up. The environmental acceptability of the ashes produced under different fuel loadings, especially their suitability for use in road constructions, were evaluated. The project included also the preparation of laboratory reference material from ash material. Guidelines were developed for sampling, sample preparation and analysis, and leaching tests. Furthermore, a quality control system, including sampling strategies, sample analysis and leaching testing, was established

  17. Coal combustion waste management study

    International Nuclear Information System (INIS)

    1993-02-01

    Coal-fired generation accounted for almost 55 percent of the production of electricity in the United States in 1990. Coal combustion generates high volumes of ash and flue gas desulfurization (FGD) wastes, estimated at almost 90 million tons. The amount of ash and flue gas desulfurization wastes generated by coal-fired power plants is expected to increase as a result of future demand growth, and as more plants comply with Title IV of the 1990 Clean Air Act Amendments. Nationwide, on average, over 30 percent of coal combustion wastes is currently recycled for use in various applications; the remaining percentage is ultimately disposed in waste management units. There are a significant number of on-site and off-site waste management units that are utilized by the electric utility industry to store or dispose of coal combustion waste. Table ES-1 summarizes the number of disposal units and estimates of waste contained at these unites by disposal unit operating status (i.e, operating or retired). Further, ICF Resources estimates that up to 120 new or replacement units may need to be constructed to service existing and new coal capacity by the year 2000. The two primary types of waste management units used by the industry are landfills and surface impoundments. Utility wastes have been exempted by Congress from RCRA Subtitle C hazardous waste regulation since 1980. As a result of this exemption, coal combustion wastes are currently being regulated under Subtitle D of RCRA. As provided under Subtitle D, wastes not classified as hazardous under Subtitle C are subject to State regulation. At the same time Congress developed this exemption, also known as the ''Bevill Exclusion,'' it directed EPA to prepare a report on coal combustion wastes and make recommendations on how they should be managed

  18. Modeling of Plasma Assisted Combustion

    Science.gov (United States)

    Akashi, Haruaki

    2012-10-01

    Recently, many experimental study of plasma-assisted combustion has been done. However, numerous complex reactions in combustion of hydrocarbons are preventing from theoritical study for clarifying inside the plasma-assisted combustion, and the effect of plasma-assist is still not understood. Shinohara and Sasaki [1,2] have reported that the shortening of flame length by irradiating microwave without increase of gas temperature. And they also reported that the same phenomena would occur when applying dielectric barrier discharges to the flame using simple hydrocarbon, methane. It is suggested that these phenomena may result by the electron heating. To clarify this phenomena, electron behavior under microwave and DBD was examined. For the first step of DBD plasma-assisted combustion simulation, electron Monte Carlo simulation in methane, oxygen and argon mixture gas(0.05:0.14:0.81) [2] has been done. Electron swarm parameters are sampled and electron energy distribution function (EEDF)s are also determined. In the combustion, gas temperature is higher(>1700K), so reduced electric field E/N becomes relatively high(>10V/cm/Torr). The electrons are accelerated to around 14 eV. This result agree with the optical emission from argon obtained by the experiment of reference [2]. Dissociation frequency of methane and oxygens are obtained in high. This might be one of the effect of plasma-assist. And it is suggested that the electrons should be high enough to dissociate methane, but plasma is not needed.[4pt] [1] K. Shinohara et al, J. Phys. D:Appl. Phys., 42, 182008 (1-7) (2009).[0pt] [2] K. Sasaki, 64th Annual Gaseous Electronic Conference, 56, 15 CT3.00001(2011).

  19. Combustive management of oil spills

    International Nuclear Information System (INIS)

    1992-01-01

    Extensive experiments with in situ incineration were performed on a desert site at the University of Arizona with very striking results. The largest incinerator, 6 feet in diameter with a 30 foot chimney, developed combustion temperatures of 3000, F, and attendant soot production approximately 1000 times less than that produced by conventional in situ burning. This soot production, in fact, is approximately 30 times less than current allowable EPA standards for incinerators and internal combustion engines. Furthermore, as a consequence of the high temperature combustion, the bum rate was established at a very high 3400 gallons per hour for this particular 6 foot diameter structure. The rudimentary design studies we have carried out relative to a seagoing 8 foot diameter incinerator have predicted that a continuous burn rate of 7000 gallons per hour is realistic. This structure was taken as a basis for operational design because it is compatible with C130 flyability, and will be inexpensive enough ($120,000 per copy) to be stored at those seaside depots throughout the US coast line in which the requisite ancillary equipments (booms, service tugs, etc.) are already deployed. The LOX experiments verified our expectations with respect to combustion of debris and various highly weathered or emulsified oils. We have concluded, however, that the use of liquid oxygen in actual beach clean up is not promising because the very high temperatures associated with this combustion are almost certain to produce environmentally deleterious effects on the beach surface and its immediately sublying structures. However, the use of liquid oxygen augmentation for shore based and flyable incinerators may still play an important role in handing the problem of accumulated debris

  20. Physics of the fuel cycle. Evaluation of methods, uncertainties and estimation of the material balance for fuels UO{sub 2} and UO{sub 2}-PuO{sub 2}; Physique du cycle du combustible evaluation des methodes, incertitudes et estimation du bilan matiere pour les combustibles UO{sub 2} et UO{sub 2}-PuO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Monier, C

    1997-09-01

    The research works of this thesis are aimed to evaluate the methods and the associated uncertainties for the material balances estimation of the burn-up UO{sub 2} and MOX fuels which intervene in the fuel cycle physics. The studies carried out are used to qualify the cycle `package` DARWIN for the PWRs material balances estimation. The elaboration and optimisation of the calculation routes are carried out following a very specific methodology, aimed at estimating the bias introduced by the modelizations simplification by a comparison with almost exact reference modelizations. Depending on the precision goals and the informations, the permissible approximation will be determined. Two calculation routes have been developed and the qualified by applying them to the used fuels isotopic analysis interpretation: one `industry-oriented` calculation route which can calculate full UO{sub 2} assemblies material balances with a 2 % precision on the main actinides, respecting the industrial specifications. This route must run with a reasonable calculation time and stay user-friendly; one reference calculation route for the precise interpretation of fuel samples made of pieces of burn-up MOX rods. Aiming to provide material balances with the best possible precision, this route does not have the same specifications concerning its use and its calculation time performance. (author)

  1. Combustion Engineering, Inc

    International Nuclear Information System (INIS)

    1980-01-01

    Four (4) 3 '' O.D. x 0.470'' nominal wall thickness (NWT) hot rotary pierced/roll reduced modified AOD/ESR tube hollows were cold pilger reduced through one pass to 2'' O.D. x 0.250'' NWT tubing. Two (2) additional hollows of same size and process history were cold pilger reduced through one pass to 2 1/8'' O.D. x 0.200'' NWT. Six (6) 3 3/4'' O.D. x 0.600'' NWT hot extruded tube hollows were cold pilger reduced through two passes to 2'' O.D. x 0.250'' NWT tubing. Four of the extrusions represented duplex AOD/ESR melting practice and two extrusions represented AOD melting practice. Twelve (12) pieces of 2 1/8'' O.D. x 0.200'' NWT x approx. 9' long tubing were final heat treated, straightened, and ultrasonically tested. Twelve (12) more pieces of 2 1/8'' O.D. tubing have been solution austenitized (1177 0 C) and are to be reaustenitized (1066 0 C), tempered (760 0 C), straightened, and ultrasonically inspected. All 2'' O.D. x 0.250'' NWT tubing is in the solution austenitized condition. Creep and stress rupture testing has continued on aged material from CarTech heat 91887 and on unaged material from CarTech heat 30182A

  2. FY1995 annual report on the advanced combustion science in microgravity field

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Research was implemented continuously from the previous year on combustion equipment enabling advanced combustion technologies, by studying combustion in a microgravity field, for the purpose of preventing environmental pollution caused by diversification of energy sources and exhaust gasses. In joint studies with NASA, the 1995 themes were continued, for which tests were conducted 34 times using Japanese drop test equipment. Further, studies were added for flammability limits and flame dynamics of spherical flames in homogeneous and heterogeneous mixed fuels. The evaluation and analysis of the experiments and test data by the microgravity test equipment were such that laser ignitions of floating or fuel-oozing droplets, spherical/cylindrical combustion of liquid fuels, for example, were studied in regards to the combustion and vaporization process of fuel droplets, that high calorie fuel combustion in microgravitation field for example was investigated in relation to the combustion characteristics of high density fuels, that flame stability of lean premixed gasses for example was researched concerning flammability limit, and that NOx generation mechanism in liquid fuel combustion was looked into in connection with emission mechanisms of pollutant gaseous materials. (NEDO)

  3. Co-combustion of coal and non-recyclable paper and plastic waste in a fluidised bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    D. Boavida; P. Abelha; I. Gulyurtlu; I. Cabrita [DEECA-INETI, Lisbon (Portugal)

    2003-10-01

    Co-combustion of waste with coal was carried out using a fluidised bed combustor with the aim of achieving a fuel mixture with little variations in its heating value and simultaneously reducing the accumulation of non-toxic waste material by upgrading them for energy purposes. Results obtained indicate that the feeding of waste materials plays an important role to achieve conditions for a stable combustion. The form in which the fuel is fed to the combustor makes a significant contribution to achieve desirable combustion performance and differences were observed in results regarding the combustion efficiency and emissions when waste was fed densified or in a fluffy state when it was burned mixed with coal. Part of the combustion of waste material, contrary to that of coal, was observed to take place in the freeboard where the temperature was as much as 150{sup o}C above that of the bed. 15 refs., 8 figs., 8 tabs.

  4. SO2 Release as a Consequence of Alternative Fuel Combustion in Cement Rotary Kiln Inlets

    DEFF Research Database (Denmark)

    Cortada Mut, Maria del Mar; Nørskov, Linda Kaare; Glarborg, Peter

    2015-01-01

    The combustion of alternative fuels in direct contact with the bed material of the rotary kiln may cause local reducing conditions and, subsequently, decomposition of sulfates from cement raw materials, increasing the SO2 concentration in the gas phase. The decomposition of sulfates increases...... the sulfur circulation and may be problematic because high sulfur circulation can cause sticky material buildup, affecting the process operation of the cement kiln system. The SO2 release from cement raw materials during combustion of pine wood and tire rubber has been studied experimentally in a high...

  5. Use of combustible wastes as fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Salamov, A.A.

    1983-01-01

    Achievements of science and technology in creating and using units for combustion of wastes with recovery of heat of the escaping gases has been systematized and generalized. Scales and outlooks are examined for the use of general, industrial and agricultural waste as fuel, composition of the waste, questions of planning and operating units for combustion of solid refuse, settling of waste water and industrial and agricultural waste. Questions are covered for preparing them for combustion use in special units with recovery of heat and at ES, aspects of environmental protection during combustion of waste, cost indicators of the employed methods of recovering the combustible waste.

  6. The combustion of biomass - the impact of its types and combustion technologies on the emission of nitrogen oxide

    Directory of Open Access Journals (Sweden)

    Mladenović Milica R.

    2016-01-01

    Full Text Available Harmonization of environmental protection and the growing energy needs of modern society promote the biomass application as a replacement for fossil fuels and a viable option to mitigate the green house gas emissions. For domestic conditions this is particularly important as more than 60% of renewables belongs to biomass. Beside numerous benefits of using biomass for energy purposes, there are certain drawbacks, one of which is a possible high emission of NOx during the combustion of these fuels. The paper presents the results of the experiments with multiple biomass types (soybean straw, cornstalk, grain biomass, sunflower oil, glycerin and paper sludge, using different combustion technologies (fluidized bed and cigarette combustion, with emphasis on the emission of NOx in the exhaust gas. A presentation of the experimental installations is given, as well as an evaluation of the effects of the fuel composition, combustion regimes and technology on the NOx emissions. As the biomass combustion took place at temperatures low enough that thermal and prompt NOx can be neglected, the conclusion is the emissions of nitrogen oxides primarily depend on the biomass composition- it is increasing with the increase of the nitrogen content, and decreases with the increase of the char content which provides catalytic surface for NOx reduction by CO. [Projekat Ministarstva nauke Republike Srbije, br. TR33042: Improvement of the industrial fluidized bed facility, in scope of technology for energy efficient and environmentally feasible combustion of various waste materials in fluidized bed i br. III42011: Development and improvement of technologies for efficient use of energy of several forms of agricultural and forest biomass in an environmentally friendly manner, with the possibility of cogeneration

  7. Vibration combustion as a prospect for utilizing firewood contaminated with radiocesium

    Science.gov (United States)

    Polezhaev, Yu. V.; Geshele, V. D.; Raskatov, I. P.; Solov'ev, V. N.; Pleshchankov, I. G.; Bida, L. A.; Levchuk, A. S.; Fokina, G. I.

    2013-01-01

    We present results of experimental investigation relevant to vibration combustion of solid fuel specimens in a Rijke tube and the interpretation of the combustion mechanism on the basis of "energy" approach. The decrease in the flame temperature is noted, which can be used to reduce the yield of low-boiling mineral components of ash, e.g., radioactive 137Cs isotope, in the volatile phase. The distribution of 137Cs in thermal conversions of firewood has been studied with the aid of computational-experimental methods, and the use of vibration combustion for utilizing the firewood contaminated with radiocesium has been suggested to decrease the emission of 137Cs into the surrounding medium.

  8. Wood products in the waste stream: Characterization and combustion emissions. Volume 1. Final report

    International Nuclear Information System (INIS)

    1992-11-01

    Waste wood is wood separated from the solid-waste stream and processed into a uniform-sized product that is reused for other purposes such as fuel. As an alternative to the combustion of fossil fuels, it has raised concerns that if it is 'contaminated' with paints, resins, preservatives, etc., unacceptable environmental impacts may be generated during combustion. Given the difficulty of separating contaminated materials from waste wood and the large energy potential existing in the resource, it is important to identify possible problems associated with contaminated waste wood combustion. The study describes research about technical, public policy, and regulatory issues that affect the processing and combustion of waste wood for fuel. The project's purpose was to provide environmental regulators, project developers, and others with data to make informed decisions on the use of waste wood materials as a combustion resource. Potential environmental problems and solutions were identified. A specific project result was the identification of combustion system operation parameters and air pollution control technologies that can minimize emissions of identified air and solid waste contaminants from combustion of wood waste

  9. Setting up experimental incineration system for low-level radioactive samples and combustion experiments

    International Nuclear Information System (INIS)

    Yumoto, Yasuhiro; Hanafusa, Tadashi; Nagamatsu, Tomohiro; Okada, Shigeru

    1997-01-01

    An incineration system was constructed which were composed of a combustion furnace (AP-150R), a cyclone dust collector, radioisotope trapping and measurement apparatus and a radioisotope storage room built in the first basement of the Radioisotope Center. Low level radioactive samples (LLRS) used for the combustion experiment were composed of combustible material or semi-combustible material containing 500 kBq of 99m TcO 4 or 23.25 kBq of 131 INa. The distribution of radioisotopes both in the inside and outside of combustion furnace were estimated. We measured radioactivity of a smoke duct gas in terminal exit of the exhaust port. In case of combustion of LLRS containing 99m TcO 4 or 131 INa, concentration of radioisotopes at the exhaust port showed less than legal concentration limit of these radioisotopes. In cases of combustion of LLRS containing 99m TcO 4 or 131 INa, decontamination factors of the incineration system were 120 and 1.1, respectively. (author)

  10. A synchronous surround increases the motion strength gain of motion.

    Science.gov (United States)

    Linares, Daniel; Nishida, Shin'ya

    2013-11-12

    Coherent motion detection is greatly enhanced by the synchronous presentation of a static surround (Linares, Motoyoshi, & Nishida, 2012). To further understand this contextual enhancement, here we measured the sensitivity to discriminate motion strength for several pedestal strengths with and without a surround. We found that the surround improved discrimination of low and medium motion strengths, but did not improve or even impaired discrimination of high motion strengths. We used motion strength discriminability to estimate the perceptual response function assuming additive noise and found that the surround increased the motion strength gain, rather than the response gain. Given that eye and body movements continuously introduce transients in the retinal image, it is possible that this strength gain occurs in natural vision.

  11. Surrounding Moving Obstacle Detection for Autonomous Driving Using Stereo Vision

    Directory of Open Access Journals (Sweden)

    Hao Sun

    2013-06-01

    Full Text Available Detection and tracking surrounding moving obstacles such as vehicles and pedestrians are crucial for the safety of mobile robotics and autonomous vehicles. This is especially the case in urban driving scenarios. This paper presents a novel framework for surrounding moving obstacles detection using binocular stereo vision. The contributions of our work are threefold. Firstly, a multiview feature matching scheme is presented for simultaneous stereo correspondence and motion correspondence searching. Secondly, the multiview geometry constraint derived from the relative camera positions in pairs of consecutive stereo views is exploited for surrounding moving obstacles detection. Thirdly, an adaptive particle filter is proposed for tracking of multiple moving obstacles in surrounding areas. Experimental results from real-world driving sequences demonstrate the effectiveness and robustness of the proposed framework.

  12. Contamination of nebulisers and surrounding air at the bedside of ...

    African Journals Online (AJOL)

    An air sampler was used to collect air samples from the surrounding bedside environment. .... individualised resealable plastic bags and stored upside down in a cooler .... conventional and mesh technology nebulisers used at home by adults.

  13. Glow phenomenon surrounding the vertical stabilizer and OMS pods

    Science.gov (United States)

    1994-01-01

    This 35mm frame, photographed as the Space Shuttle Columbia was orbiting Earth during a 'night' pass, documents the glow phenomenon surrounding the vertical stabilizer and the Orbital Maneuvering System (OMS) pods of the spacecraft.

  14. Distributed Low Temperature Combustion: Fundamental Understanding of Combustion Regime Transitions

    Science.gov (United States)

    2016-09-07

    behaviour as compared to ethanol. The latter fuel has also been considered along with methane. Work has also been performed on the further assessment of... behaviour as compared to ethanol. The latter fuel has also been considered along with methane. Work has also been performed on the further assess- ment of...identification of various combustion gas states. A range of Damköhler numbers (Da) from the conventional propagating flamelet regime well into the distributed

  15. Combustion synthesis: A new approach for preparation of thermoelectric zinc antimonide compounds

    Energy Technology Data Exchange (ETDEWEB)

    Rouessac, F., E-mail: Florence.Rouessac@univ-montp2.fr [Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-UM2-ENSCM-UM1, C2M Universite Montpellier 2, CC 1504 Place Eugene Bataillon, 34095 Montpellier Cedex 5 (France); Ayral, R.-M. [Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-UM2-ENSCM-UM1, C2M Universite Montpellier 2, CC 1504 Place Eugene Bataillon, 34095 Montpellier Cedex 5 (France)

    2012-07-25

    Highlights: Black-Right-Pointing-Pointer Reliable preparation method of thermoelectric materials. Black-Right-Pointing-Pointer Formation of zinc antimonide by the combustion synthesis method is investigated. Black-Right-Pointing-Pointer XRD and Raman spectroscopy as a function of temperature. Black-Right-Pointing-Pointer SHS: a new way for synthesizing thermoelectric materials. - Abstract: Due to the interesting properties of Zn{sub 4}Sb{sub 3} thermoelectric material, a reliable preparation method of this material is required. In this study, the formation of zinc antimonides by the combustion synthesis method is investigated and subjected to characterization using X-ray diffraction and Raman spectroscopy as a function of temperature. The results show that combustion synthesis can be a new way for synthesizing these thermoelectric materials.

  16. Monitoring program of surrounding of the NPP SE-EBO

    International Nuclear Information System (INIS)

    Dobis, L.; Kostial, J.

    1997-01-01

    The paper dealt with monitoring program of radiation control of surrounding of the NPP Bohunice, which has the aim: (1) to ensure the control of influence of work of the NPP Bohunice on the environment in their surrounding; (2) to ensure the back-ground for regular brief of control and supervisory organs about condition of the environment in surrounding of the NPP Bohunice; (3) to maintain the expected technical level of control of the NPP Bohunice and to exploit optimally the technical means; (4) to solicit permanently the data about the radioactivity of environment in surrounding of the NPP Bohunice for forming of files of the data; (5) to exploit purposefully the technical equipment, technical workers and to maintain their in permanent emergency and technical eligibility for the case of the breakdown; (6) to obtain permanently the files of the values for qualification of the reference levels. This program of monitoring includes the radiation control of surrounding of the NPP Bohunice, in the time of normal work of power-station's blocks, inclusively of all types of trouble-shooting and repairer works in surrounding of the NPP Bohunice, up to distance 20 km from power-station. The monitoring includes: outlets from the NPP Bohunice, monitoring of radiation characteristics in surrounding of the NPP Bohunice, (aerosols, fall-outs, soil), the links of food chains: (grass and fodder, milk, agriculture products), hydrosphere in surrounding (surface waters, drink water, bores of radiation control in complex of the NPP Bohunice, components of the hydrosphere), measurement of radiation from external sources (measurement of the dose rates, measurement of the doses [sk

  17. Chromatic induction from surrounding stimuli under perceptual suppression.

    Science.gov (United States)

    Horiuchi, Koji; Kuriki, Ichiro; Tokunaga, Rumi; Matsumiya, Kazumichi; Shioiri, Satoshi

    2014-11-01

    The appearance of colors can be affected by their spatiotemporal context. The shift in color appearance according to the surrounding colors is called color induction or chromatic induction; in particular, the shift in opponent color of the surround is called chromatic contrast. To investigate whether chromatic induction occurs even when the chromatic surround is imperceptible, we measured chromatic induction during interocular suppression. A multicolor or uniform color field was presented as the surround stimulus, and a colored continuous flash suppression (CFS) stimulus was presented to the dominant eye of each subject. The subjects were asked to report the appearance of the test field only when the stationary surround stimulus is invisible by interocular suppression with CFS. The resulting shifts in color appearance due to chromatic induction were significant even under the conditions of interocular suppression for all surround stimuli. The magnitude of chromatic induction differed with the surround conditions, and this difference was preserved regardless of the viewing conditions. The chromatic induction effect was reduced by CFS, in proportion to the magnitude of chromatic induction under natural (i.e., no-CFS) viewing conditions. According to an analysis with linear model fitting, we revealed the presence of at least two kinds of subprocesses for chromatic induction that reside at higher and lower levels than the site of interocular suppression. One mechanism yields different degrees of chromatic induction based on the complexity of the surround, which is unaffected by interocular suppression, while the other mechanism changes its output with interocular suppression acting as a gain control. Our results imply that the total chromatic induction effect is achieved via a linear summation of outputs from mechanisms that reside at different levels of visual processing.

  18. The Spontaneous Combustion of Railway Ties and Asphalt Shingles

    Science.gov (United States)

    Leslie, Geoffrey

    Many Low Carbon Fuels (LCFs) present unknown spontaneous combustion risks, which must be quantified before their use as fossil fuel replacements. Wood and coal spontaneous combustion is well understood; however, LCFs weather, and subsequent chemical changes could affect their spontaneous combustion properties. LCF spontaneous combustion could lead to accidental fires with possible loss of life, limb and property. The spontaneous combustion risks of two LCFs, discarded creosote-treated wooden railway ties and roofing asphalt shingles, were investigated with calorimetry and heat transfer experiments. Chemical changes due to weathering were studied with pyrolysis-Gas Chromatography/Mass Spectrometry (py-GC/MS). Creosote-treated wooden railway tie dust, roofing asphalt shingle particles, poplar wood pellets, and petroleum coke self-heating were studied with isothermal calorimetry. Railway tie dust and asphalt shingle heat transfer were characterized with a guarded hot plate. Petroleum coke self-heating was consistent with coal, while both poplar pellets and railway tie dust were found to be more reactive compared to oven test results of similar materials. The observed increase in reactivity was probably a result of significant moisture contenint in the pellet and railway tie dust. Critical conditions for spontaneous combustion were evaluated with the Frank-Kamenetskii parameter, assuming an ambient temperature of 40°C and constant moisture content. Kamenetskii calculations indicate that a 1.6 m cube of railway tie dust, or a 58 m cube of asphalt particles, would be unstable and combust. LCF chemistry may have been affected by weathering, which would cause chemical changes that affect their spontaneous combustion properties. Therefore, railway tie wood and roofing asphalt shingle chemistry were investigated by identifying products of 250° and 550°C pyrolysis with py-GC/MS. Railway tie wood pyrolyzates did not show signs of weathering; in contrast, asphalt pyrolysis

  19. Combustion synthesis of TiB2-based cermets: modeling and experimental results

    International Nuclear Information System (INIS)

    Martinez Pacheco, M.; Bouma, R.H.B.; Katgerman, L.

    2008-01-01

    TiB 2 -based cermets are prepared by combustion synthesis followed by a pressing stage in a granulate medium. Products obtained by combustion synthesis are characterized by a large remaining porosity (typically 50%). To produce dense cermets, a subsequent densification step is performed after the combustion process and when the reacted material is still hot. To design the process, numerical simulations are carried out and compared to experimental results. In addition, physical and electrical properties of the products related to electrical contact applications are evaluated. (orig.)

  20. Fundamental study of single biomass particle combustion

    Energy Technology Data Exchange (ETDEWEB)

    Momeni, M.

    2013-06-01

    This thesis is a comprehensive study of single biomass particle combustion. The effect of particle shape and size and operating conditions on biomass conversion characteristics were investigated experimentally and theoretically. The experimental samples were divided in two groups: particles with regular shapes (spheres and cylinders) and particles with irregular shapes (almost flake-like). A CAMSIZER analyser (Retsch Technology GMBH) was used to determine the size and shape of the particles via Dynamical Digital Image Processing. The experiments were performed in a single particle reactor under well-defined conditions, and the complete combustion processes were recorded as video sequences by a CCD camera installed in the set-up. One of the project objectives is to simulate conditions reasonably close to the conditions in a power plant boiler, i.e., reasonably high temperatures (up to 1600 deg. C) and varying oxygen concentrations in the 5 to 20% range. A one-dimensional mathematical model was used to simulate all the intraparticle conversion processes (drying, recondensation, devolatilisation, char gasification/oxidation and heat/mass/momentum transfer) within single particles of different shapes and size under various conditions. The model also predicts the flame layer domain of a single particle. The model was validated by experimental results under different conditions; good agreement between the model predictions and the experimental data was observed. Both the experimental and modelling results showed that cylindrical particles lose mass faster than spherical particles of a similar volume (mass) and that the burnout time is reduced by increasing the particle aspect ratio (surface area to volume ratio). Very similar conversion times were observed for cylindrical particles with nearly identical surface area to volume ratios. Similar conversion times were also observed for two size classes of pulverised particles (with irregular shapes) made from the same type of

  1. Acid digestion and pressurization control in combustible radwaste treatment

    International Nuclear Information System (INIS)

    Allen, C.R.; Cowan, R.G.; Grelecki, C.J.

    1978-01-01

    Acid digestion has been developed to reduce the volume of combustible nuclear waste materials, while converting them to an inert, noncombustible residue. A 100 kg/day test unit has recently been constructed to process radioactively contaminated combustible wastes. The unit, called the Radioactive Acid Digestion Test Unit (RADTU) was completed in September, 1977, and is currently undergoing nonradioactive shakedown tests. Radioactive operation is expected in May, 1978. Because of uncertainties in waste composition and reactivity, the system was required to contain pressurizations. This led to the development of a simple and inexpensive system, which is capable of attenuating a shock wave from a full scale vapor detonation. The system has potential application in a wide spectrum of chemical reactors, since the fabrication materials are resistant to a very wide range of corrosive chemical attack

  2. Acid digestion of combustible wastes: a status report

    International Nuclear Information System (INIS)

    Lerch, R.E.

    1975-05-01

    Work at the Hanford Engineering Development Laboratory on development of the acid digestion process for treating combustible wastes is discussed. Materials such as paper, rubber, and plastics are readily decomposed into a low volume, noncombustible residue. Engineering results using the Acid Digestion Test Unit are discussed. Tests to date generally duplicated earlier laboratory results with respect to waste processing rates, volume reduction, off-gas generation rates and volumes, acid consumption, and completeness of reaction. Demonstrated processing rates were as high as 5 kg/hr for short duration run periods. The tests indicated engineering feasibility of the acid digestion process and showed acid digestion to be a potentially attractive method for treating combustible nuclear wastes. Other areas discussed in the report are behavior of plutonium and americium during acid digestion, behavior of various construction materials, and safety. An integrated flowsheet for operation of an acid digestion unit is also presented. (U.S.)

  3. Hydrogen Generation, Combustibility and Mitigation in Nuclear Power Plant Systems

    International Nuclear Information System (INIS)

    Talha, K.A.; El-Sheikh, B.M.; Gad El-Mawla, A.S.

    2003-01-01

    The nuclear power plant is provided with features to insure safety. The engineered safety features (ESFs) are devoted to set operating conditions under accident conditions. If ESFs fail to apply in some accidents, this would lead to what called severe accidents, and core damage. In this case hydrogen will be generated from different sources particularly from metal-water reactions. Since the containment is the final barrier to protect the environment from the release of radioactive materials; its integrity should not be threatened. In recent years, hydrogen concentration represents a real problem if it exceeds the combustibility limits. This work is devoted to calculate the amount of hydrogen to be generated, indelicate its combustibility and how to inertize the containment using different gases to maintain its integrity and protect the environment from the release of radioactive materials

  4. Solution-combustion synthesized nickel-substituted spinel cathode materials (LiNixMn2-xO4; 0≤x≤0.2) for lithium ion battery: enhancing energy storage, capacity retention, and lithium ion transport

    CSIR Research Space (South Africa)

    Kebede, MA

    2014-01-01

    Full Text Available Spherically shaped Ni-substituted LiNi(subx)Mn(sub2-x)O(sub4) (x=0, 0.1, 0.2) spinel cathode materials for lithium ion battery with high first cycle discharge capacity and remarkable cycling performance were synthesized using the solution...

  5. Analytical V TH and S models for (DMG-GC-stack) surrounding-gate MOSFET

    Science.gov (United States)

    Aouaj, Abdellah; Bouziane, Ahmed; Nouaçry, Ahmed

    2012-01-01

    This article presents an analytical model of surface potential, threshold voltage and subthreshold swing for a new structure of surrounding-gate MOSFET by combining dual-material gate, graded channel and gate stack. By comparison with published results, it is shown that the new MOSFET structure can improve the immunity of CMOS-based devices in the nanoscale regime against short-channel effects.

  6. Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ojeda, William de

    2010-07-31

    The project which extended from November 2005 to May of 2010 demonstrated the application of Low Temperature Combustion (LTC) with engine out NOx levels of 0.2 g/bhp-hr throughout the program target load of 12.6bar BMEP. The project showed that the range of loads could be extended to 16.5bar BMEP, therefore matching the reference lug line of the base 2007 MY Navistar 6.4L V8 engine. Results showed that the application of LTC provided a dramatic improvement over engine out emissions when compared to the base engine. Furthermore LTC improved thermal efficiency by over 5% from the base production engine when using the steady state 13 mode composite test as a benchmark. The key enablers included improvements in the air, fuel injection, and cooling systems made in Phases I and II. The outcome was the product of a careful integration of each component under an intelligent control system. The engine hardware provided the conditions to support LTC and the controller provided the necessary robustness for a stable combustion. Phase III provided a detailed account on the injection strategy used to meet the high load requirements. During this phase, the control strategy was implemented in a production automotive grade ECU to perform cycle-by-cycle combustion feedback on each of the engine cylinders. The control interacted on a cycle base with the injection system and with the Turbo-EGR systems according to their respective time constants. The result was a unique system that could, first, help optimize the combustion system and maintain high efficiency, and secondly, extend the steady state results to the transient mode of operation. The engine was upgraded in Phase IV with a Variable Valve Actuation system and a hybrid EGR loop. The impact of the more versatile EGR loop did not provide significant advantages, however the application of VVA proved to be an enabler to further extend the operation of LTC and gain considerable benefits in fuel economy and soot reduction. Finally

  7. Microscale combustion and power generation

    CERN Document Server

    Cadou, Christopher; Ju, Yiguang

    2014-01-01

    Recent advances in microfabrication technologies have enabled the development of entirely new classes of small-scale devices with applications in fields ranging from biomedicine, to wireless communication and computing, to reconnaissance, and to augmentation of human function. In many cases, however, what these devices can actually accomplish is limited by the low energy density of their energy storage and conversion systems. This breakthrough book brings together in one place the information necessary to develop the high energy density combustion-based power sources that will enable many of these devices to realize their full potential. Engineers and scientists working in energy-related fields will find: An overview of the fundamental physics and phenomena of microscale combustion; Presentations of the latest modeling and simulation techniques for gasphase and catalytic micro-reactors; The latest results from experiments in small-scale liquid film, microtube, and porous combustors, micro-thrusters, a...

  8. Combustion process science and technology

    Science.gov (United States)

    Hale, Robert R.

    1989-01-01

    An important and substantial area of technical work in which noncontact temperature measurement (NCTM) is desired is that involving combustion process research. In the planning for this workshop, it was hoped that W. Serignano would provide a briefing regarding the experimental requirements for thermal measurements to support such research. The particular features of thermal measurement requirements included those describing the timeline for combustion experiments, the requirements for thermal control and diagnostics of temperature and other related thermal measurements and the criticality to the involved science to parametric features of measurement capability including precision, repeatability, stability, and resolution. In addition, it was hoped that definitions could be provided which characterize the needs for concurrent imaging as it relates to science observations during the conduct of experimentation.

  9. Dynamical issues in combustion theory

    International Nuclear Information System (INIS)

    Fife, P.C.; Williams, F.

    1991-01-01

    This book looks at the world of combustion phenomena covering the following topics: modeling, which involves the elucidation of the essential features of a given phenomenon through physical insight and knowledge of experimental results, devising appropriate asymptotic and computational methods, and developing sound mathematical theories. Papers in this book describe how all of these challenges have been met for particular examples within a number of common combustion scenarios: reactive shocks, low Mach number premixed reactive flow, nonpremixed phenomena, and solid propellants. The types of phenomena examined are also diverse: the stability and other properties of steady structures, the long time dynamics of evolving solutions, properties of interfaces and shocks, including curvature effects, and spatio-temporal patterns

  10. SPECIFIC EMISSIONS FROM BIOMASS COMBUSTION

    Directory of Open Access Journals (Sweden)

    Pavel Skopec

    2014-02-01

    Full Text Available This paper deals with determining the specific emissions from the combustion of two kinds of biomass fuels in a small-scale boiler. The tested fuels were pellets made of wood and pellets made of rape plant straw. In order to evaluate the specific emissions, several combustion experiments were carried out using a commercial 25 kW pellet-fired boiler. The specific emissions of CO, SO2 and NOx were evaluated in relation to a unit of burned fuel, a unit of calorific value and a unit of produced heat. The specific emissions were compared with some data acquired from the reference literature, with relatively different results. The differences depend mainly on the procedure used for determining the values, and references provide no information about this. Although some of our experimental results may fit with one of the reference sources, they do not fit with the other. The reliability of the references is therefore disputable.

  11. Steady state HNG combustion modeling

    Energy Technology Data Exchange (ETDEWEB)

    Louwers, J.; Gadiot, G.M.H.J.L. [TNO Prins Maurits Lab., Rijswijk (Netherlands); Brewster, M.Q. [Univ. of Illinois, Urbana, IL (United States); Son, S.F. [Los Alamos National Lab., NM (United States); Parr, T.; Hanson-Parr, D. [Naval Air Warfare Center, China Lake, CA (United States)

    1998-04-01

    Two simplified modeling approaches are used to model the combustion of Hydrazinium Nitroformate (HNF, N{sub 2}H{sub 5}-C(NO{sub 2}){sub 3}). The condensed phase is treated by high activation energy asymptotics. The gas phase is treated by two limit cases: the classical high activation energy, and the recently introduced low activation energy approach. This results in simplification of the gas phase energy equation, making an (approximate) analytical solution possible. The results of both models are compared with experimental results of HNF combustion. It is shown that the low activation energy approach yields better agreement with experimental observations (e.g. regression rate and temperature sensitivity), than the high activation energy approach.

  12. Oxy-coal Combustion Studies

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, J. [Univ. of Utah, Salt Lake City, UT (United States); Eddings, E. [Univ. of Utah, Salt Lake City, UT (United States); Lighty, J. [Univ. of Utah, Salt Lake City, UT (United States); Ring, T. [Univ. of Utah, Salt Lake City, UT (United States); Smith, P. [Univ. of Utah, Salt Lake City, UT (United States); Thornock, J. [Univ. of Utah, Salt Lake City, UT (United States); Y Jia, W. Morris [Univ. of Utah, Salt Lake City, UT (United States); Pedel, J. [Univ. of Utah, Salt Lake City, UT (United States); Rezeai, D. [Univ. of Utah, Salt Lake City, UT (United States); Wang, L. [Univ. of Utah, Salt Lake City, UT (United States); Zhang, J. [Univ. of Utah, Salt Lake City, UT (United States); Kelly, K. [Univ. of Utah, Salt Lake City, UT (United States)

    2012-01-06

    The objective of this project is to move toward the development of a predictive capability with quantified uncertainty bounds for pilot-scale, single-burner, oxy-coal operation. This validation research brings together multi-scale experimental measurements and computer simulations. The combination of simulation development and validation experiments is designed to lead to predictive tools for the performance of existing air fired pulverized coal boilers that have been retrofitted to various oxy-firing configurations. In addition, this report also describes novel research results related to oxy-combustion in circulating fluidized beds. For pulverized coal combustion configurations, particular attention is focused on the effect of oxy-firing on ignition and coal-flame stability, and on the subsequent partitioning mechanisms of the ash aerosol.

  13. Design of a High Intensity Turbulent Combustion System

    Science.gov (United States)

    2015-05-01

    mixing of the reactants in chemical reactors, boilers , furnaces and mixing of fuel and air in engines take place in turbulent flow. One of the most...determining flame speed. When a tube containing combustible mixture, the flame speed is the propagation speed of the flame front towards the unburned...stress criteria is effective when the material is ductile in nature. This stress theory is developed from the 44 ’distortion energy failure theory

  14. Forest Fragments Surrounded by Sugar Cane Are More Inhospitable to Terrestrial Amphibian Abundance Than Fragments Surrounded by Pasture

    Directory of Open Access Journals (Sweden)

    Paula Eveline Ribeiro D’Anunciação

    2013-01-01

    Full Text Available In recent years, there has been increasing interest in matrix-type influence on forest fragments. Terrestrial amphibians are good bioindicators for this kind of research because of low vagility and high philopatry. This study compared richness, abundance, and species composition of terrestrial amphibians through pitfall traps in two sets of semideciduous seasonal forest fragments in southeastern Brazil, according to the predominant surrounding matrix (sugar cane and pasture. There were no differences in richness, but fragments surrounded by sugar cane had the lowest abundance of amphibians, whereas fragments surrounded by pastures had greater abundance. The most abundant species, Rhinella ornata, showed no biometric differences between fragment groups but like many other amphibians sampled showed very low numbers of individuals in fragments dominated by sugar cane fields. Our data indicate that the sugar cane matrix negatively influences the community of amphibians present in fragments surrounded by this type of land use.

  15. Coal combustion technology in China

    International Nuclear Information System (INIS)

    Huang, Z.X.

    1994-01-01

    Coal is the most important energy source in China, the environmental pollution problem derived from coal burning is rather serious in China. The present author discusses coal burning technologies both in boilers and industrial furnaces and their relations with environmental protection problems in China. The technological situations of Circulating Fluidized Bed Coal Combustor, Pulverized Coal Combustor with Aerodynamic Flame Holder and Coal Water Slurry Combustion have been discussed here as some of the interesting problems in China only. (author). 3 refs

  16. Example Problems in LES Combustion

    Science.gov (United States)

    2016-09-26

    Lesieur, M., Turbulence in Fluids , 2nd Revised Ed., Fluid Mechanics and Its Applications, Vol. 1, Kluwer Academic Publishers, Boston, Massachusetts, 1990...34, Journal of Fluid Mechanics , Vol. 238, 1992, pp. 155-185. 5. Hirsch, C., Numerical Computation of Internal and External Flows, Vol. 2, Computational...reaction mechanisms for the oxidation of hydrocarbon fuels in flames", Combustion Science and Technology, Vol. 27, 1981, pp. 31-43. 14. Spalding, D.B

  17. Combustion synthesis and characterization of uranium and thorium tellurides

    International Nuclear Information System (INIS)

    Czechowicz, D.G.

    1985-10-01

    This report describes an investigation of the chemical systems uranium-tellurium and thorium-tellurium. A novel synthesis technique, combustion synthesis, which uses the exothermic heat of reaction rather than externally supplied heat, was utilized to form the phases UTe, U 3 Te 4 , and UTe 2 in the U-Te system and the phases ThTe, Th 2 Te 3 , and ThTe 2 in the Th-Te system from reactions of the type U/sub x/ + Te/sub y/ = U/sub x/Te/sub y/. With this synthetic method, U-Te and Th-Te products could be formed in a matter of seconds, and the purity of the products was often greater than that of the starting materials used. Control over final product stoichiometry was found to be very difficult. The product phase distribution observed in combustion products, as determined by x-ray diffraction, electron microprobe, and optical metallographic methods, was found to be spatially complex. Lattice constants were calculated from x-ray diffraction patterns for the compounds UTe, U 3 Te 4 , and ThTe. SOLGASMIX thermodynamic equilibrium calculations were performed using available and estimated thermodynamic data on the system U-Te-O in an attempt to understand the products formed by combustion. Adiabatic combustion reaction temperatures for specific U-Te and Th-Te reactions were also calculated utilizing available and estimated thermodynamic data. 71 refs., 31 figs., 15 tabs

  18. Automatic combustion control of the ArcelorMittal Tubarao coke oven batteries

    Energy Technology Data Exchange (ETDEWEB)

    L. Barbosa de Oliveira Mello; C.-H. Sampaio Dandrea; G.-H. Marietto Goncalves; A. Estevao Torres; N.-L. Biccas

    2008-05-15

    The objective of the automatic combustion control is to guarantee the operational stability of the coke batteries based on the control of the coking time and consequently, minimize the reduction of useful life of the ovens. This control is guided by a mathematical model whose inputs are process variables and raw materials parameters and outputs are combustion parameters. Therefore, this paper will present the evolution of the performance of the burning process, providing a stability of the coking time.

  19. FY2011 Annual Progress Report for Propulsion Materials

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Patrick B. [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States); Schutte, Carol L. [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States); Gibbs, Jerry L. [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

    2011-12-01

    Annual Progress Report for Propulsion Materials focusing on enabling and innovative materials technologies that are critical in improving the efficiency of advanced engines by providing enabling materials support for combustion, hybrid, and power electronics development.

  20. Combustion instability modeling and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, R.J.; Yang, V.; Santavicca, D.A. [Pennsylvania State Univ., University Park, PA (United States)] [and others

    1995-10-01

    It is well known that the two key elements for achieving low emissions and high performance in a gas turbine combustor are to simultaneously establish (1) a lean combustion zone for maintaining low NO{sub x} emissions and (2) rapid mixing for good ignition and flame stability. However, these requirements, when coupled with the short combustor lengths used to limit the residence time for NO formation typical of advanced gas turbine combustors, can lead to problems regarding unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions, as well as the occurrence of combustion instabilities. Clearly, the key to successful gas turbine development is based on understanding the effects of geometry and operating conditions on combustion instability, emissions (including UHC, CO and NO{sub x}) and performance. The concurrent development of suitable analytical and numerical models that are validated with experimental studies is important for achieving this objective. A major benefit of the present research will be to provide for the first time an experimentally verified model of emissions and performance of gas turbine combustors.

  1. Combustion char characterisation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rosenberg, P; Ingermann Petersen, H; Sund Soerensen, H; Thomsen, E; Guvad, C

    1996-06-01

    The aim was to correlate reactivity measures of raw coals and the maceral concentrates of the coals obtained in a previous project with the morphology of the produced chars by using a wire grid devolatilization method. Work involved determination of morphology, macroporosity and a detailed study by Scanning Electron Microscopy (SEM). Systematic variations in the texture of chars produced in different temperature domains and heating rates were demonstrated by using incident light microscopy on polished blocks and by SEM studies directly on the surfaces of untreated particles. Results suggest that work in the field of char reactivity estimates and correlations between char morphology and coal petrography can be accomplished only on chars produced under heating rates and temperatures comparable to those for the intended use of coal. A general correlation between the coals` petrography and the the morphology of high temperature chars was found. The SEM study of the chars revealed that during the devolatilization period the particles fuse and the macroporosity and thus the morphotypes are formed. After devolatilization ceases, secondary micropores are formed. These develop in number and size throughout the medium combustion interval. At the end of the combustion interval the macrostructure breaks down, caused by coalescence of the increased number of microspores. This can be observed as a change in the morphology and the macroporosity of the chars. Results indicate that char reactivity is a function of the macroporosity and thus the morphology of combustion chars. (AB) 34 refs.

  2. Management of coal combustion wastes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-02-01

    It has been estimated that 780 Mt of coal combustion products (CCPs) were produced worldwide in 2010. Only about 53.5% were utilised, the rest went to storage or disposal sites. Disposal of coal combustion waste (CCW) on-site at a power plant may involve decades-long accumulation of waste, with hundreds of thousands, if not millions, of tonnes of dry ash or wet ash slurry being stored. In December 2008, a coal combustion waste pond in Kingston, Tennessee, USA burst. Over 4 million cubic metres of ash sludge poured out, burying houses and rivers in tonnes of toxic waste. Clean-up is expected to continue into 2014 and will cost $1.2 billion. The incident drew worldwide attention to the risk of CCW disposal. This caused a number of countries to review CCW management methods and regulations. The report begins by outlining the physical and chemical characteristics of the different type of ashes generated in a coal-fired power plant. The amounts of CCPs produced and regulations on CCW management in selected countries have been compiled. The CCW disposal methods are then discussed. Finally, the potential environmental impacts and human health risks of CCW disposal, together with the methods used to prevent them, are reviewed.

  3. Modeling the internal combustion engine

    Science.gov (United States)

    Zeleznik, F. J.; Mcbride, B. J.

    1985-01-01

    A flexible and computationally economical model of the internal combustion engine was developed for use on large digital computer systems. It is based on a system of ordinary differential equations for cylinder-averaged properties. The computer program is capable of multicycle calculations, with some parameters varying from cycle to cycle, and has restart capabilities. It can accommodate a broad spectrum of reactants, permits changes in physical properties, and offers a wide selection of alternative modeling functions without any reprogramming. It readily adapts to the amount of information available in a particular case because the model is in fact a hierarchy of five models. The models range from a simple model requiring only thermodynamic properties to a complex model demanding full combustion kinetics, transport properties, and poppet valve flow characteristics. Among its many features the model includes heat transfer, valve timing, supercharging, motoring, finite burning rates, cycle-to-cycle variations in air-fuel ratio, humid air, residual and recirculated exhaust gas, and full combustion kinetics.

  4. Catalytic reduction of emissions from small scale wood combustion. State of the art

    Energy Technology Data Exchange (ETDEWEB)

    Hargitai, T.; Silversand, F.A. [Katator AB, Lund (Sweden)

    1998-12-31

    Small-scale combustion of big-fuel often results in excessive emissions of volatile organic compounds (VOC), polyaromatic compounds (PAM) and carbon monoxide (CO). These compounds have a negative impact on human health and urban air quality. The predominant volatile organic compounds present in flue gases from big-fuel combustion are propylene, ethylene, butadiene, methanol, ethanol, methane, phenol and benzene. The poor combustion performance of some wood stoves has in certain cases led to legislation against small-scale combustion of big-fuel in urban areas. Catalytic cleaning is one very efficient way of decreasing the environmental impacts of big-fuel combustion. Several studies concerning catalytic purification of flue gases from big-fuel combustion have been presented over the years. Several problems must be addressed when designing a catalyst for this application: Clogging problems from deposition of ashes and particulates in the catalyst; Catalyst poisoning by sulphur, phosphorus, alkali metals etc.; Catalyst fouling due to deposition of ashes and particulates; Catalyst overheating at high flue-gas temperatures and Poor catalyst performance during start-up Most studies have been focused on monolith-type catalysts and- the conversion of CO, VOC and PAH typically is above 80 %. The observed problems are associated with increased pressure drop due to catalyst clogging and decreased catalyst performance due to fouling and poisoning. In most cases precious metals, preferably Pt. have been used as active combustion catalyst. Precious metals have a high activity for the combustion of CO and hydrocarbons and a fair stability against poisoning with compounds present in flue gases from big-fuel, e.g. sulphur and alkali metals. The majority of the studies on precious metals have been focused on Pt. Rh and Pd, which are especially active in catalytic combustion. Some metal oxides are used in catalytic combustion, especially at low temperatures (e.g. in VOC abatement

  5. Experimental studies on combustion of composite biomass pellets in fluidized bed.

    Science.gov (United States)

    Guo, Feihong; Zhong, Zhaoping

    2017-12-01

    This work presents studies on the combustion of Composite Biomass Pellets (CBP S ) in fluidized bed using bauxite particles as the bed material. Prior to the combustion experiment, cold-flow characterization and thermogravimetric analysis are performed to investigate the effect of air velocity and combustion mechanism of CBP S . The cold-state test shows that CBPs and bauxite particles fluidize well in the fluidized bed. However, because of the presence of large CBPs, optimization of the fluidization velocity is rather challenging. CBPs can gather at the bottom of the fluidized bed at lower gas velocities. On the contrary, when the velocity is too high, they accumulate in the upper section of the fluidized bed. The suitable fluidization velocity for the system in this study was found to be between 1.5-2.0m/s. At the same time, it is found that the critical fluidization velocity and the pressure fluctuation of the two-component system increase with the increase of CBPs mass concentration. The thermogravimetric experiment verifies that the combustion of CBPs is a first-order reaction, and it is divided into three stages: (i) dehydration, (ii) release and combustion of the volatile and (iii) the coke combustion. The combustion of CBPs is mainly based on the stage of volatile combustion, and its activation energy is greater than that of char combustion. During the combustion test, CBP S are burned at a 10kg/h feed rate, while the excess air is varied from 25% to 100%. Temperatures of the bed and flue gas concentrations (O 2 , CO, SO 2 and NO) are recorded. CBPs can be burnt stably, and the temperature of dense phase is maintained at 765-780°C. With the increase of the air velocity, the main combustion region has a tendency to move up. While the combustion is stable, O 2 and CO 2 concentrations are maintained at about 7%, and 12%, respectively. The concentration of SO 2 in the flue gas after the initial stage of combustion is nearly zero. Furthermore, NO concentration

  6. Electrically fired incineration of combustible radioactive waste

    International Nuclear Information System (INIS)

    Charlesworth, D.; Hill, M.

    1985-01-01

    Du Pont Company and Shirco, Inc. are developing a process to incinerate plutonium-contaminated combustible waste in an electrically fired incineration system. Preliminary development was completed at Shirco, Inc. prior to installing an incineration system at the Savannah River Laboratory (SRL), which is operated by Du Pont for the US Department of Energy (DOE). The waste consists of disposable protective clothing, cleaning materials, used filter elements, and miscellaneous materials exposed to plutonium contamination. Incinerator performance testing, using physically representative nonradioactive materials, was completed in March 1983 at Shirco's Pilot Test Facility in Dallas, TX. Based on the test results, equipment sizing and mechanical begin of a full-scale process were completed by June 1983. The full-scale unit is being installed at SRL to confirm the initial performance testing and is scheduled to begin in June 1985. Remote operation and maintenance of the system is required, since the system will eventually be installed in an isolated process cell. Initial operation of the process will use nonradioactive simulated waste. 2 figs., 2 tabs

  7. UTILIZATION OF LOW NOx COAL COMBUSTION BY-PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    J.Y. Hwang; X. Huang; M.G. McKimpson; R.E. Tieder; A.M. Hein; J.M. Gillis; D.C. Popko; K.L. Paxton; Z. Li; X. Liu; X. Song; R.I. Kramer

    1998-12-01

    Low NO{sub x} combustion practices are critical for reducing NO{sub x} emissions from power plants. These low NO{sub x} combustion practices, however, generate high residual carbon contents in the fly ash produced. These high carbon contents threaten utilization of this combustion by-product. This research has successfully developed a separation technology to render fly ash into useful, quality-controlled materials. This technology offers great flexibility and has been shown to be applicable to all of the fly ashes tested (more than 10). The separated materials can be utilized in traditional fly ash applications, such as cement and concrete, as well as in nontraditional applications such as plastic fillers, metal matrix composites, refractories, and carbon adsorbents. Technologies to use beneficiated fly ash in these applications are being successfully developed. In the future, we will continue to refine the separation and utilization technologies to expand the utilization of fly ash. The disposal of more than 31 million tons of fly ash per year is an important environmental issue. With continued development, it will be possible to increase economic, energy and environmental benefits by re-directing more of this fly ash into useful materials.

  8. Isotope Dilution - Thermal Ionisation Mass Spectrometric Analysis for Tin in a Fly Ash Material; Analisis de Estano en una Ceniza de Combustion mediante Espectrometria de Masas de Ionizacion Termica con Dilucion Isotopica

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, C; Fernandez, M; Quejido, A L

    2006-07-01

    Isotope dilution-thermal ionisation mass spectrometry (ID-TIMS) analysis has been applied to the determination of tin in a fly ash sample supplied by the EC Joint Research Centre (Ispra, Italy). The proposed procedure includes the silica gel/phosphoric acid technique for tin thermal ionisation activation and a strict heating protocol for isotope ratio measurements. Instrumental mass discrimination factor has been previously determined measuring a natural tin standard solution. Spike solutions has been prepared from 112Sn-enriched metal and quantified by reverse isotope dilution analysis. Two sample aliquots were spiked and tin was extracted with 4,5 M HCI during 25 min ultrasound exposure time. Due to the complex matrix of this fly ash material, a two-step purification stage using ion-exchange chromatography was required prior TIMS analysis. Obtained results for the two sample-spike blends (10,10 + - 0,55 y 10,50 + - 0,64 imolg-1) are comprarable, both value and uncertainty. Also a good reproducibility is observed between measurements. The proposed ID-TIMS procedure, as a primary method and due to the lack of fly ash reference material certified for tin content, can be used to validate more routine methodologies applied to tin determination in this kind of materials. (Author) 75 refs.

  9. Analysis of cathode materials of perovskite structure for solid oxide fuel cells, sofc s; Analisis de materiales catodicos de estructura perovskita para celdas de combustible de oxido solido, sofcs

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado F, J.; Espino V, J.; Avalos R, L. [Universidad Michoacana de San Nicolas de Hidalgo, Facultad de Ingenieria Quimica, Santiago Tapia 403, Morelia, Michoacan (Mexico)

    2015-07-01

    Fuel cells directly and efficiently convert the chemical energy of a fuel into electrical energy. Of the various types of fuel cells, the solid oxide (Sofc), combine the advantages in environmentally benign energy generation with fuel flexibility. However, the need for high operating temperatures (800 - 1000 grades C) has resulted in high costs and major challenges in relation to the compatibility the cathode materials. As a result, there have been significant efforts in the development of intermediate temperature Sofc (500 - 700 grades C). A key obstacle for operation in this temperature range is the limited activity of traditional cathode materials for electrochemical reduction oxygen. In this article, the progress of recent years is discussed in cathodes for Sofc perovskite structure (ABO{sub 3}), more efficient than the traditionally used La{sub 1-x}Sr{sub x}MnO{sub 3-δ} (LSM) or (La, Sr) CoO{sub 3}. Such is the case of mixed conductors (MIEC) double perovskite structure (A A B{sub 2}O{sub 5+δ}) using different doping elements as La, Sr, Fe, Ti, Cr, Sm, Co, Cu, Pr, Nd, Gd, dy, Mn, among others, which could improve the operational performance of existing cathode materials, promoting the development of optimized intermediate temperature Sofc designs. (Author)

  10. Analysis of the effects of combining air separation with combustion in a zero emissions (ZEITMOP) cycle

    International Nuclear Information System (INIS)

    Foy, Kirsten; McGovern, Jim

    2007-01-01

    The ZEITMOP cycle is a zero emissions (oxyfuel) power plant cycle proposed by Evgeny Yantovski that uses oxygen ion transport membranes to extract the oxygen required for combustion from air. A current proposed configuration of the cycle requires an oxygen ion transport membrane air separation unit operating at 920 deg. C and a separate combustion chamber operating at 1400 deg. C. If oxygen is consumed by a chemical reaction on the permeate side of an oxygen transport membrane, the oxygen flux is larger, so the air separation unit can be physically smaller. In addition, if this reaction is exothermic, the air separation unit is heated by the reaction, requiring no additional heating. Combustion fulfils both of these requirements, so combustion in the oxygen transport membrane air separation unit would allow a smaller air separation unit, which would also act as a combustion chamber. Unfortunately, a combustion temperature of 1400 deg. C will damage most oxygen transport membranes available today. However, new materials are continually being developed and investigated, so it may be possible to have an oxygen transport membrane chamber operating at 1400 deg. C in the short to medium term future. Alternatively the combustion chamber may be cooled, allowing it to operate at more realistic temperatures for currently available oxygen transport membranes. Controlling the operation temperature of the combined unit requires changing the mass flow rates of various streams of fluid in the cycle. This will have an effect on the work and heat transfers in the cycle. It is possible to calculate the theoretical effects of these changes in temperature. This paper presents an analysis investigating the impact of combining the air separator and the combustion chamber. The efficiency of the cycle was calculated at various operation temperatures for the combined oxygen transport membrane combustion chamber. The results were compared to the efficiency of the current cycle. The changes

  11. Material Programming

    DEFF Research Database (Denmark)

    Vallgårda, Anna; Boer, Laurens; Tsaknaki, Vasiliki

    2017-01-01

    . Consequently we ask what the practice of programming and giving form to such materials would be like? How would we be able to familiarize ourselves with the dynamics of these materials and their different combinations of cause and effect? Which tools would we need and what would they look like? Will we program......, and color, but additionally being capable of sensing, actuating, and computing. Indeed, computers will not be things in and by themselves, but embedded into the materials that make up our surroundings. This also means that the way we interact with computers and the way we program them, will change...... these computational composites through external computers and then transfer the code them, or will the programming happen closer to the materials? In this feature we outline a new research program that floats between imagined futures and the development of a material programming practice....

  12. Method and apparatus for active control of combustion rate through modulation of heat transfer from the combustion chamber wall

    Science.gov (United States)

    Roberts, Jr., Charles E.; Chadwell, Christopher J.

    2004-09-21

    The flame propagation rate resulting from a combustion event in the combustion chamber of an internal combustion engine is controlled by modulation of the heat transfer from the combustion flame to the combustion chamber walls. In one embodiment, heat transfer from the combustion flame to the combustion chamber walls is mechanically modulated by a movable member that is inserted into, or withdrawn from, the combustion chamber thereby changing the shape of the combustion chamber and the combustion chamber wall surface area. In another embodiment, heat transfer from the combustion flame to the combustion chamber walls is modulated by cooling the surface of a portion of the combustion chamber wall that is in close proximity to the area of the combustion chamber where flame speed control is desired.

  13. IEA combustion agreement : a collaborative task on alternative fuels in combustion

    International Nuclear Information System (INIS)

    Larmi, M.

    2009-01-01

    The focus of the alternative fuels in combustion task of the International Energy Agency is on high efficiency engine combustion, furnace combustion, and combustion chemistry. The objectives of the task are to develop optimum combustion for dedicated fuels by fully utilizing the physical and chemical properties of synthetic and renewable fuels; a significant reduction in carbon dioxide, NOx and particulate matter emissions; determine the minimum emission levels for dedicated fuels; and meet future emission standards of engines without or with minimum after-treatment. This presentation discussed the alternative fuels task and addressed issues such as synthetic fuel properties and benefits. The anticipated future roadmap was presented along with a list of the synthetic and renewable engine fuels to be studied, such as neat oxygenates like alcohols and ethers, biogas/methane and gas combustion, fuel blends, dual fuel combustion, high cetane number diesel fuels like synthetic Fischer-Tropsch diesel fuel and hydrogenated vegetable oil, and low CN number fuels. Implementation examples were also discussed, such as fuel spray studies in optical spray bombs; combustion research in optical engines and combustion chambers; studies on reaction kinetics of combustion and emission formation; studies on fuel properties and ignition behaviour; combustion studies on research engines; combustion optimization; implementing the optimum combustion in research engines; and emission measurements. Overall milestone examples and the overall schedule of participating countries were also presented. figs.

  14. Spontaneous human combustion in the light of the 21st century.

    Science.gov (United States)

    Koljonen, Virve; Kluger, Nicolas

    2012-01-01

    The term "spontaneous human combustion" refers to a situation when a human body is found with significant portions of the middle parts of the body reduced to ashes, much less damage to the head and extremities, and minimal damage to the direct surroundings of the body. Typically, no observable source of ignition is found in the vicinity of the victim and a bad smelling oily substance is noted. In the past, such a situation was erroneously attributed to supernatural powers, as such phenomenon occurs in the absence of any witness. The purpose of this review article was to analyze articles published from January 1, 2000, on this unique type of burn injury. Further aims were to gather and present data on the causes and events leading to this situation. The literature was reviewed with PubMed interface using the key words spontaneous human combustion and preternatural combustion. Specific inclusion criteria resulted in 12 patients. A unique sequence of events takes place for the human body to incinerate to ashes. The flame burn victim has to die for the body fat to start melting. A tear in the skin has to occur for the melted fat to impregnate the charred clothes, igniting a wick effect that produces localized heat for extended period. A phenomenon called spontaneous human combustion is reality. The term "spontaneous human combustion" has nuances which are not applicable to this situation or to these modern times, therefore we suggest a new term "fat wick burns."

  15. Radiological impact of phosphogypsum in the Surrounding Ecosystem

    International Nuclear Information System (INIS)

    Al-Attar, L.; Al-Oudat, M.; Budier, Y.; Khalili, H.; Hamwi, A.; Kanakri, S.

    2011-01-01

    This study was carried out to assess the radiological impact of Syrian PG piles in the compartments of the surrounding ecosystem. Therefore, estimating the distribution of naturally occurring radionuclides (i.e. 2 26 Ra, 2 38 U, 2 32 Th, 2 10 Po and 2 10 Pb) in the raw materials, product and by-product of the Syrian phosphate fertilizer industry was essential. The obtained data revealed that 2 26 Ra retained in PG with a mean activity of 318 Bq kg-1. Uranium content in PG was low since it remained in the produced phosphoric acid. However, over 80% of 2 32 Th, 2 10 Po and 2 10 Pb partitioned in PG. The presence of PG piles did not increase the concentration of 2 22 Rn nor gamma rays exposure dose in the studied area. The annual effective dose was only 0.082 mSv y-1. The geometric mean of total suspended solids was ca. 85 g m-3. The concentration of the radionuclides in filtration and runoff waters were below the detection limits; and were much lower than the permissible limits set for drinking water by the WHO in ground and Qattina Lake waters. Eastern sites soil samples of PG piles were of the highest activity concentrations, due to the characterised western and north-western wind in the area, but remained within the natural levels reported in Syrian soil. The impact of PG piles on plants varied upon the plant species. Significantly, higher concentrations of the radionuclides were recorded for grass in comparison to broad-leaved plants. Among the species that naturally grown on PG piles, Inula, Ecballium and Polygonium may be radionuclides accumulators. Nevertheless, a determined effort is needed on national level to achieve a common and coherent approach to regulate PG piles or to consider it a resource material rather than waste or residue. The presence of PG piles did not increase the concentration of 2 22 Rn nor gamma rays exposure dose in the studied area. The annual effective dose was only 0.082 mSv y -1 . The geometric mean of total suspended solids was ca

  16. Combustion of Solid Propellants (La Combustion des Propergols Solides)

    Science.gov (United States)

    1991-07-01

    the of ether and ethyl alcohol and removing objective of these lectures to give a this solvent. Instead of having a fibrous comprehensive understanding...do cetto esrne do Les propergols composites, A matrice confifrences une description tout A fait A polymarique charg~o pst, un oxydant at un jour des...rusa., De nouveaux souvant suppos6 qua la vitesa des gaz de oxydes de for ultrafirts mont aujourd’hui combustion est n~gligeable at qua d~velopps pour

  17. Placental vascular responses are dependent on surrounding tissue

    DEFF Research Database (Denmark)

    Brøgger, Torbjørn Halle

    -depth understanding of the mechanism regulating blood flow and perfusion is necessary if we are to come up with new ideas for intervention and treatment. Method: From fresh born placentas stem villi arteries were carefully dissected. The artery branches were divided. The surrounding tissue was removed from one end...... and was left untouched in the other end. Then using wire myography they were investigated in terms of contractility and sensitivity to physiological relevant human-like agonists. Results: Sensitivity to PGF2α, Tx-analog, 5-HT and endothelin-1 was significantly lower in arteries with intact surrounding tissue...... compared to arteries stripped of the tissue. The maximal force development was also significantly lower in arteries with surrounding tissue, when they were depolarized high extracellular [K+] or stimulated with PGF2α or endotheline-1. Conclusion: The perivascular tissue significantly alters stem villi...

  18. Surrounding rock stress analysis of underground high level waste repository

    International Nuclear Information System (INIS)

    Liu Wengang; Wang Ju; Wang Guangdi

    2006-01-01

    During decay of nuclear waste, enormous energy was released, which results in temperature change of surrounding rock of depository. Thermal stress was produced because thermal expansion of rock was controlled. Internal structure of surrounding rock was damaged and strength of rock was weakened. So, variation of stress was a dynamic process with the variation of temperature. BeiShan region of Gansu province was determined to be the depository field in the future, it is essential to make research on granite in this region. In the process of experiment, basic physical parameters of granite were analyzed preliminary with MTS. Long range temperature and stress filed was simulated considering the damage effect of surrounding rock, and rules of temperature and stress was achieved. (authors)

  19. Straw combustion on slow-moving grates

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen

    2005-01-01

    Combustion of straw in grate-based boilers is often associated with high emission levels and relatively poor fuel burnout. A numerical grate combustion model was developed to assist in improving the combustion performance of these boilers. The model is based on a one-dimensional ‘‘walking......-column’’ approach and includes the energy equations for both the fuel and the gas accounting for heat transfer between the two phases. The model gives important insight into the combustion process and provides inlet conditions for a computational fluid dynamics analysis of the freeboard. The model predictions...... indicate the existence of two distinct combustion modes. Combustion air temperature and mass flow-rate are the two parameters determining the mode. There is a significant difference in reaction rates (ignition velocity) and temperature levels between the two modes. Model predictions were compared...

  20. Oxy-fuel combustion of solid fuels

    DEFF Research Database (Denmark)

    Toftegaard, Maja Bøg; Brix, Jacob; Jensen, Peter Arendt

    2010-01-01

    Oxy-fuel combustion is suggested as one of the possible, promising technologies for capturing CO2 from power plants. The concept of oxy-fuel combustion is removal of nitrogen from the oxidizer to carry out the combustion process in oxygen and, in most concepts, recycled flue gas to lower the flame...... provide additional options for improvement of process economics are however likewise investigated. Of particular interest is the change of the combustion process induced by the exchange of carbon dioxide and water vapor for nitrogen as diluent. This paper reviews the published knowledge on the oxy......-fuel process and focuses particularly on the combustion fundamentals, i.e. flame temperatures and heat transfer, ignition and burnout, emissions, and fly ash characteristics. Knowledge is currently available regarding both an entire oxy-fuel power plant and the combustion fundamentals. However, several...