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Sample records for burner les bruleurs

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  3. Laminar partially premixed flame stability - application to domestic burner; Stabilite de flammes laminaires partiellement premelangees. Application aux bruleurs domestiques

    Energy Technology Data Exchange (ETDEWEB)

    Lacour, C.

    2006-05-15

    Phenomena responsible of partially premixed laminar flame stabilisation are investigated on a rich premixed burner configuration. The structure and aerodynamic of the flame generated by a cooking model burner are characterized by Planar Laser Induced Fluorescence of OH radical and Particle Image Velocimetry. The flame behaviour is studied from a stable reference case toward blow-out by varying the flow inlet conditions, the burner geometry and its thermal properties. The flame can be considered as two neighbour and independent reactive zones, each consisting of a double edge flame. The upper double flame stabilisation is similar to the one of a Bunsen burner with a flame-holder attached base and a flame tip stabilized in the flow according to the ratio of the flow velocity and flame speed of the rich pre-mixture. The bottom double flame is stabilized at the crossing point of the stoichiometric flame speed. The flame is finally blown out when there is no more crossing point. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Salentey, L.

    2002-04-15

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

  5. Measurements of the concentration of major chemical species in the flame of a test burner with a air swirling system; Mesures de concentration d`especes chimiques majoritaires dans la flamme d`un bruleur modele avec mise en rotation de l`air

    Energy Technology Data Exchange (ETDEWEB)

    Albert, St. [Gaz de France (GDF), 93 - La Plaine-Saint-Denis (France); Most, J.M.; Poireault, B. [Centre National de la Recherche Scientifique (CNRS), 86 - Poitiers (France)

    1996-12-31

    The study of combustion in industrial burners remains difficult because of the complexity of the equipments used: materials geometry, tri-dimensional flows etc.. The phenomena that control the combustion in a gas burner with a swirl air system has been studied thanks to a collaboration between the Direction of Research of Gaz de France (GdF) and the Laboratory for Combustion and Detonation Research (LCD) of the French National Centre of Scientific Research (CNRS). The burner used is developed by the LCD and the measurements of stable chemical species were performed by the CERSTA centre of GdF. These series of tests, performed in confined environment, have permitted to identify some of the parameters that influence combustion chemistry. Mapping of chemical species allows to distinguish 5 zones of flame development and also the zones of nitrogen oxides formation. Methane is rapidly centrifuged a few millimeters above the injection pipe and centrifuged with rotating combustion air. Carbon monoxide occurs immediately in the central recirculation zone which is weakly reactive (no oxygen and no methane). Oxygen content increases downflow from this area and carbon dioxide reaches its concentration maxima. CO formation decreases when the swirl number increases and CO{sub 2} formation occurs earlier. On the contrary, the emissions of CO and CH{sub 4} do not depend on the swirl value and the NO{sub x} values are only slightly dependent on this value. (J.S.)

  6. Effect of burner geometry on swirl stabilized methane/air flames: A joint LES/OH-PLIF/PIV study

    KAUST Repository

    Liu, X.

    2017-07-04

    Large eddy simulation (LES) using a transported PDF model and OH-PLIF/PIV experiments were carried out to investigate the quarl effects on the structures of swirl stabilized methane/air flames. Two different quarls were investigated, one straight cylindrical quarl and one diverging conical quarl. The experiments show that the flames are significantly different with the two quarls. With the straight cylindrical quarl a compact blue flame is observed while with the diverging conical quarl the flame appears to be long and yellow indicating a sooty flame structure. The PIV results show the formation of a stronger flow recirculation inside the diverging conical quarl than that in the straight quarl. LES results reveal further details of the flow and mixing process inside the quarl. The results show that with the diverging quarl vortex breakdown occurs much earlier towards the upstream of the quarl. As a result the fuel is convected into the air flow tube and a diffusion flame is stabilized inside the air flow tube upstream the quarl. With the straight quarl, vortex breakdown occurs at a downstream location in the quarl. The scalar dissipation rate in the shear layer of the fuel jet is high, which prevents the stabilization of a diffusion flame in the proximity of the fuel nozzle; instead, a compact partially premixed flame with two distinct heat release layers is stablized in a downstream region in the quarl, which allows for the fuel and air to mix in the quarl before combustion and a lower formation rate of soot. The results showed that the Eulerian Stochastic Fields transported PDF method can well predict the details of the swirl flame dynamics.

  7. Multifuel burner

    Energy Technology Data Exchange (ETDEWEB)

    Raybould, J.D.

    1982-04-28

    A design is proposed for turbulent burner (B) for simultaneous burning of powder, liquid and/or gaseous fuel (F). The liquid F is sprayed with the help of a rotation sprayer arranged on the axis of the burner device. The gas can be supplied through the opening made in the dish-shaped bottom encompassing the central part of the B. The powder F (aeromixture) enters the combustion zone through the channels with vortex blades arranged on the periphery of the bottom of the B. Through the annular channel arranged around the rotation sprayer, primary air is supplied, and through the channels arranged on the periphery of the B, secondary air. The percentage of solid F during operation of the B can be 75-90%.

  8. Burner cap assembly

    Energy Technology Data Exchange (ETDEWEB)

    Craver, A.F.

    1974-05-07

    A new gas burner for domestic gas ranges is economical in cost, has the proper configuration for the aesthetics of the housewife, and overcomes certain undesirable operational features of conventional gas burners. The design eliminates the burner base, eliminates the venturi section of the mixing tube, incorporates a new cap with a novel port configuration, and, in the preferred version, eliminates the air shutter at the primary air inlet to the mixing tube. Because the voluminous conventional burner base has been eliminated, the amount of unburned gas escaping after turning the burner off is no longer sizable enough to disturb the cook. The burner produces less carbon monoxide but a higher temperature and greater efficiency than conventional burners and may be placed much closer to the utensil. Thus, no expensive supplemental mounting brackets are needed below the bottom of the burner box; the burner may even be mounted directly on the oven top without danger of oven contraction/expansion moving the unit out of the allowable burner-height range. The unit requires less cleaning and is less susceptible to closure by lint, dirt, and grease.

  9. Performance evaluation of biogas burners

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, A.; Tiwari, G.N.; Srivastava, V.K.; Yadav, Y.P. (Indian Inst. of Tech., New Delhi (India). Centre of Energy Studies)

    1991-01-01

    The results of testing some biogas burners of various brands are presented. A wide variation is found in their performance under similar conditions of testing. Parametric investigations have also been carried out on a typical biogas burner. These investigations reveal that the burner efficiency is a strong function of biogas flow pressure, pan-size and its position over the burner head. (author).

  10. Pressurized burner test facility

    Energy Technology Data Exchange (ETDEWEB)

    Maloney, D.J.; Norton, T.S.; Hadley, M.A. [Morgantown Energy Technology Center, WV (United States)

    1993-06-01

    The Morgantown Energy Technology Center (METC) is currently fabricating a high-pressure burner test facility. The facility was designed to support the development of gas turbine combustion systems fired on natural gas and coal-derived gaseous fuels containing fuel-bound nitrogen. Upon completion of fabrication and shake-down testing in October 1993, the facility will be available for use by industrial and university partners through Cooperative Research and Development Agreements (CRADAs) or through other cooperative arrangements. This paper describes the burner test facility and associated operating parameter ranges and informs interested parties of the availability of the facility.

  11. Improved burner without pump

    Energy Technology Data Exchange (ETDEWEB)

    Graat, H.W.; Remie, H.T.; Verhagen, A.M.

    1980-10-02

    The burner described in main patent 2828319 is operated with fluid pulverised fuel and air in a nearly stochiometric ratio. In order to achieve correct ignition with this composition, it is proposed to insert a heatable body, preferably a wire spiral or ignition spiral in the area of the pulverising and mixing chamber.

  12. Dark Matter Burners

    Energy Technology Data Exchange (ETDEWEB)

    Moskalenko, Igor V.; /Stanford U., HEPL; Wai, Lawrence L.; /SLAC

    2007-02-28

    We show that a star orbiting close enough to an adiabatically grown supermassive black hole (SMBH) can capture weakly interacting massive particles (WIMPs) at an extremely high rate. The stellar luminosity due to annihilation of captured WIMPs in the stellar core may be comparable to or even exceed the luminosity of the star due to thermonuclear burning. The model thus predicts the existence of unusual stars, essentially WIMP burners, in the vicinity of a SMBH. We find that the most efficient WIMP burners are stars with degenerate electron cores, e.g. white dwarfs (WDs); such WDs may have a very high surface temperature. If found, such stars would provide evidence for the existence of particle dark matter and can possibly be used to establish its density profile. On the other hand, the lack of such unusual stars may provide constraints on the WIMP density near the SMBH, as well as the WIMP-nucleus scattering and pair annihilation cross-sections.

  13. Waste burner overfire draft system

    Energy Technology Data Exchange (ETDEWEB)

    Kahlert, G.; Pommer, L.; Davis, J.; Whebell, B.

    1977-11-22

    An overfire draft system for a waste burner is disclosed. Such system comprises air vents arranged circumferentially around the base of the burner for communicating the interior of the burner to the atmosphere and a draft modulated damper plate located in each air vent for automatically regulating the volume of overfire air delivered to the interior of the burner. Each draft modulated damper plate is provided with a lower lip which is deflected by a predetermined angle with respect to the plate to create an aerodynamic lift effect with large opening moment to assist the damper plate in its response under low air velocity conditions, and an oppositely deflected upper lip with proportionately less bent surface to avoid flutter or hunting of the damper as it approaches the maximum open position and to provide added dynamic opening force. The overfire draft system is also provided with ducts connected to the air vents and oriented so as to direct air tangentially around the base of the burner and toward the lower inside wall of the burner so as to minimize the disturbance of the inside air. The waste burner may also be provided with draft modulated or forced air vents arranged circumferentially at mid-elevation around the burner and duct means connected to such vents and directed at a small angle with the radius of the burner so as to cause turbulence in the flame zone and reduce the vertical velocity of gases above the fire, thus reducing emission of particulate materials.

  14. Pressurized burner test facility

    Energy Technology Data Exchange (ETDEWEB)

    Maloney, D.J.; Norton, T.S.; Hadley, M.A.

    1993-09-01

    The US Department of Energy`s METC has recently completed construction and commissioning of a new high-pressure combustion research facility. Utilities servicing the facility enable combustion tests at scales up to 3 MW (10 MM Btu/h) and pressures in excess of 3000 kPa (30 atm). These include a preheated, high-pressure air supply that can deliver up to 1.7 kg/s (3.7 lbs/s) of combustion air, and a high-pressure, natural gas compressor that can deliver 0.8 kg/s (.19 lbs/s). In the summer of 1994 METC`s syngas generator is scheduled to come on line, at which time combustion tests on a range of fuel gases from low to medium to high heating values will be possible. The syngas generator will simulate a range of fuel gas compositions characteristic of coal gasification product streams. As part of the combustion facility, a high-pressure burner test facility is currently being constructed to support the development of gas turbine combustion systems fired on natural gas and coal-derived gaseous fuels containing fuel-bound nitrogen. The facility, illustrated in Figure 1, is a 61-centimeter (24-inch) diameter, refractory-lined vessel of modular construction, offering the flexibility to test a variety of NO{sub x} control concepts. Burner test modules are sandwiched between gas inlet and sampling plenums with a maximum combustion test zone of 2.2 m (90 inches) in length. Modules are custom designed for specific burners.

  15. Refractoriless liquid fuel burner

    Energy Technology Data Exchange (ETDEWEB)

    Musil, J.E.

    1986-07-15

    A liquid fuel burner head is described which consists of: A. a generally annular burner head housing spacedly enveloping a generally cylindrical primary air assembly, the head and assembly each having corresponding forward and rearward ends, (a) the primary air assembly having a plurality of internal primary air supply passage means extending in a generally forwardly direction in the assembly and emerging through annularly disposed primary air port means at the forward end of the primary air assembly, (b) means effective to produce a swirl of primary air in one direction about the axis of the primary air assembly as the air emerges from the primary air port means, (c) means associated with the primary air port means for adjusting the location of flame origin forward of and relative to the primary air port means, (d) the primary air assembly including a liquid fuel supply passage and a nozzle, the nozzle being centrally disposed at the forward end of the primary air assembly and encompassed by the primary air port means, the liquid fuel nozzle being effective to discharge a substantially fan-like spray of liquid fuel just forward of and across the primary air port means, (e) the primary air assembly and the nozzle together being axially movable relative to the housing between forwardmost and rearwardmost positions respectively responsive to change in burner firing rate between minimum and maximum; B. secondary air supply passage means disposed in the space between the housing and the primary air assembly; C. means rearwardly of the secondary air directional means and port means effective to meter the amount of secondary air supplied air port means from a lesser quantity when the primary air assembly and nozzle are in their forwardmost position to a greater quantity when the primary air assembly and nozzle are in their rearwardmost position.

  16. Flame monitoring enhances burner management

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, T.; Bailey, R.; Fuller, T.; Daw, S.; Finney, C.; Stallings, J. [Babcock & Wilcox Research Center (USA)

    2003-02-01

    A new burner monitoring and diagnostic system called Flame Doctor offers users a more precise and discriminating understanding of burner conditions. Alpha testing on Unit 4 at AmerenUE's Meramec power plant in St. Louis, MO, USA and Beta testing is underway at plants owned by Dynegy and Allegheny Energy. 6 refs., 3 figs.

  17. A coal dust burner

    Energy Technology Data Exchange (ETDEWEB)

    Vakhrshev, B.M.; Khasnullin, I.G.; Krauze, Ye.G.; Ushakov, Yu.A.; Zinovyev, V.G.

    1982-01-01

    The burner for combustion of coal dust fuel, primarily, in rotating furnaces, contains coaxially disposed pipes, a branch pipe for feeding in the air mixture and a rotating mechanism. The first two pipes are switched in to an air source. The third pipe on the input end has an oblique section and the pipe may be rotated around an axis by a mechanism. The first pipe has ports and it may be moved in an axial direction. By installing the third pipe in the first and second positions, it is possible to direct the dust coming from the branch pipe along the central (the larger part of the dust) or the central pipe, respectively, which makes it possible to regulate the configuration of the torch and its temperature. Hot air is sucked from the furnace through the ports in the perforated first pipe to the mouth of the burner, which makes it possible to intensify combustion. By moving the fifitpipe to the right it is possible to overlap the ports with the projections and to rule out suction of the air. The possibility of regulating combustion in wide ranges makes it possible to reduce the expenditure of fuel by 2 to 3 percent.

  18. Radial lean direct injection burner

    Science.gov (United States)

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

    2012-09-04

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

  19. Catalyzed Ceramic Burner Material

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Amy S., Dr.

    2012-06-29

    Catalyzed combustion offers the advantages of increased fuel efficiency, decreased emissions (both NOx and CO), and an expanded operating range. These performance improvements are related to the ability of the catalyst to stabilize a flame at or within the burner media and to combust fuel at much lower temperatures. This technology has a diverse set of applications in industrial and commercial heating, including boilers for the paper, food and chemical industries. However, wide spread adoption of catalyzed combustion has been limited by the high cost of precious metals needed for the catalyst materials. The primary objective of this project was the development of an innovative catalyzed burner media for commercial and small industrial boiler applications that drastically reduce the unit cost of the catalyzed media without sacrificing the benefits associated with catalyzed combustion. The scope of this program was to identify both the optimum substrate material as well as the best performing catalyst construction to meet or exceed industry standards for durability, cost, energy efficiency, and emissions. It was anticipated that commercial implementation of this technology would result in significant energy savings and reduced emissions. Based on demonstrated achievements, there is a potential to reduce NOx emissions by 40,000 TPY and natural gas consumption by 8.9 TBtu in industries that heavily utilize natural gas for process heating. These industries include food manufacturing, polymer processing, and pulp and paper manufacturing. Initial evaluation of commercial solutions and upcoming EPA regulations suggests that small to midsized boilers in industrial and commercial markets could possibly see the greatest benefit from this technology. While out of scope for the current program, an extension of this technology could also be applied to catalytic oxidation for volatile organic compounds (VOCs). Considerable progress has been made over the course of the grant

  20. Burner ignition system

    Science.gov (United States)

    Carignan, Forest J.

    1986-01-21

    An electronic ignition system for a gas burner is battery operated. The battery voltage is applied through a DC-DC chopper to a step-up transformer to charge a capacitor which provides the ignition spark. The step-up transformer has a significant leakage reactance in order to limit current flow from the battery during initial charging of the capacitor. A tank circuit at the input of the transformer returns magnetizing current resulting from the leakage reactance to the primary in succeeding cycles. An SCR in the output circuit is gated through a voltage divider which senses current flow through a flame. Once the flame is sensed, further sparks are precluded. The same flame sensor enables a thermopile driven main valve actuating circuit. A safety valve in series with the main gas valve responds to a control pressure thermostatically applied through a diaphragm. The valve closes after a predetermined delay determined by a time delay orifice if the pilot gas is not ignited.

  1. Afnor NF D 35-330. Gas-fired central heating boilers. Type B{sub 11} and B{sub 11BIS} boilers fitted with atmospheric burners of nominal heat input not exceeding 70 kW. (European standard EN 297); Afnor NF D 35-330. Chaudieres de chauffage central utilisant les combustibles gazeux. Chaudieres des types B{sub 11} et B{sub 11BIS} equipees de bruleurs atmospheriques dont le debit calorifique nominal est inferieur ou egal a 70 kW. (Norme europeenne EN 297)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-10-01

    This standard document defines the specifications and testing techniques relative to the manufacturing, safety, energy rational use, functioning capacity, classification and labeling of gas-fueled heating plants. It replaces the previous NF D 35-331 norm from November 1989 which comprised the NF D 35-331 norm from January 1980, its additives 1 (January 1980) and 2 (June 1984), its modifications 1 (July 1980), 2 (September 1986), 3 (December 1988) and 4 (November 1989) and the D 30-005 experimental norm of November 1991. (J.S.)

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

    DEFF Research Database (Denmark)

    Yang, Yang

    This thesis represents the research on swirling flow using large eddy simulation(LES). Three cases from the Sydney swirl burner database have been chosen as test cases; one medium swirl isothermal case N29S054, one high swirl isothermal case N16S159 and one medium swirl reacting case SM1...

  3. Ecothal burner development; Ecothal braennarutveckling

    Energy Technology Data Exchange (ETDEWEB)

    Lewin, Thomas [KANTHAL AB, Hallstahammar (Sweden)

    2004-08-01

    A SER burner system with catalytic cleaning have been optimised for an outer tube OD 100-115 mm. The aim has been to develop a burner with an emission of nitrogen oxides below 50 ppm and an efficiency higher than 80%. An optimised burner system have been realised but will not be stable enough for commercialisation. In order to fullfill the requirements it have to be regulated with closed loop oxygen sensor system regulating the air/gas supply (Lambda-value). Practically it is possible to reach 200-300 ppm nitrogen oxide with an efficiency around 70-80%. Following work have to focus on how to improve the stability considering geometrical changes when in operation but also towards accomodation of production tolerances and fluctuations in gas supply systems.

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

    NARCIS (Netherlands)

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

    2012-01-01

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

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

    NARCIS (Netherlands)

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

    2012-01-01

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

  6. Pulverized fuel-oxygen burner

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Curtis; Patterson, Brad; Perdue, Jayson

    2017-09-05

    A burner assembly combines oxygen and fuel to produce a flame. The burner assembly includes an oxygen supply tube adapted to receive a stream of oxygen and a solid fuel conduit arranged to extend through the oxygen tube to convey a stream of fluidized, pulverized, solid fuel into a flame chamber. Oxygen flowing through the oxygen supply tube passes generally tangentially through a first set of oxygen-injection holes formed in the solid fuel conduit and off-tangentially from a second set of oxygen-injection holes formed in the solid fuel conduit and then mixes with fluidized, pulverized, solid fuel passing through the solid fuel conduit to create an oxygen-fuel mixture in a downstream portion of the solid fuel conduit. This mixture is discharged into a flame chamber and ignited in the flame chamber to produce a flame.

  7. Pluto: New modulating vaporizing - burner with small power

    Energy Technology Data Exchange (ETDEWEB)

    Eger, M.; Schlup, E.; Wueest, J. [Toby AG, Solothurn (Switzerland); Schelp, A.

    2003-07-01

    Starting from a existing Kerosene burner, a modulating oil burner suitable for European light oil was developed for low power operation. This burner combines the advantages of vaporising burner, premix burner and surface burner. This burner stands for low pollutant emission, extremely low operating noise for use in living rooms and reliable modulation of load in the range of e.g. 6 to 16,5 kW, or 3 to 9 kW. The paper presents principles of function and the most important features of this burner. (orig.)

  8. Computational fluid dynamics in oil burner design

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, T.A. [Brookhaven National Labs., Upton, NY (United States)

    1997-09-01

    In Computational Fluid Dynamics, the differential equations which describe flow, heat transfer, and mass transfer are approximately solved using a very laborious numerical procedure. Flows of practical interest to burner designs are always turbulent, adding to the complexity of requiring a turbulence model. This paper presents a model for burner design.

  9. 14 CFR 31.47 - Burners.

    Science.gov (United States)

    2010-01-01

    ... emergency operation. (d) The burner system (including the burner unit, controls, fuel lines, fuel cells...) Five hours at the maximum fuel pressure for which approval is sought, with a burn time for each one... intermediate fuel pressure, with a burn time for each one minute cycle of three to ten seconds. An...

  10. Burners

    Science.gov (United States)

    ... Situations Pets and Animals myhealthfinder Food and Nutrition Healthy Food Choices Weight Loss and Diet Plans Nutrients and Nutritional Info Sugar and Sugar Substitutes Exercise and Fitness Exercise Basics Sports Safety Injury Rehabilitation Emotional Well- ...

  11. DESIGN AND DEVELOPMENT OF MILD COMBUSTION BURNER

    Directory of Open Access Journals (Sweden)

    M.M. Noor

    2013-12-01

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

  12. LES of an ignition sequence in a gas turbine engine

    Energy Technology Data Exchange (ETDEWEB)

    Boileau, M.; Staffelbach, G.; Cuenot, B. [CERFACS, Toulouse (France); Poinsot, T. [IMFT - CNRS, Toulouse (France); Berat, C. [Turbomeca (SAFRAN group), Bordes (France)

    2008-07-15

    Being able to ignite or reignite a gas turbine engine in a cold and rarefied atmosphere is a critical issue for many manufacturers. From a fundamental point of view, the ignition of the first burner and the flame propagation from one burner to another are phenomena that are usually not studied. The present work is a large eddy simulation (LES) of these phenomena. To simulate a complete ignition sequence in an annular chamber, LES has been applied to the full 360 geometry, including 18 burners. This geometry corresponds to a real gas turbine chamber. Massively parallel computing (700 processors on a Cray XT3 machine) was essential to perform such a large calculation. Results show that liquid fuel injection has a strong influence on the ignition times. Moreover, the rate of flame progress from burner to burner is much higher than the turbulent flame speed due to a major effect of thermal expansion. This flame speed is also strongly modified by the main burner aerodynamics due to the swirled injection. Finally, the variability of the combustor sectors and quadrant ignition times is highlighted. (author)

  13. Burners and combustion apparatus for carbon nanomaterial production

    Science.gov (United States)

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

    2007-10-09

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

  14. CHP Integrated with Burners for Packaged Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Castaldini, Carlo; Darby, Eric

    2013-09-30

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

  15. IMPROVEMENT OF OPERATIONAL CHARACTERISTICS OF ELECTRIC COOKER BURNERS

    Directory of Open Access Journals (Sweden)

    I. M. Kirick

    2008-01-01

    Full Text Available On the basis of a complex theoretical and experimental investigations a principally new design of small inertial burner for electric cookers has been developed that significantly out-perform burners of conventional types. 

  16. Fuel-flexible burner apparatus and method for fired heaters

    Energy Technology Data Exchange (ETDEWEB)

    Zink, Darton J.; Isaacs, Rex K.; Jamaluddin, A. S. (Jamal); Benson, Charles E.; Pellizzari, Roberto O.; Little, Cody L.; Marty, Seth A.; Imel, K. Parker; Barnes, Jonathon E.; Parker, Chris S.

    2017-03-14

    A burner apparatus for a fired heating system and a method of burner operation. The burner provides stable operation when burning gas fuels having heating values ranging from low to high and accommodates sudden wide changes in the Wobbe value of the fuel delivered to the burner. The burner apparatus includes a plurality of exterior fuel ejectors and has an exterior notch which extends around the burner wall for receiving and combusting a portion of the gas fuel. At least a portion of the hot combustion product gas produced in the exterior notch is delivered through channels formed in the burner wall to the combustion area at the forward end of the burner. As the Wobbe value of the gas fuel decreases, one or more outer series of addition ejectors can be automatically activated as needed to maintain the amount of heat output desired.

  17. Improved radiant burner material. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Milewski, J.V.; Shoultz, R.A.; Bourque, M.M.; Milewski, E.B. [and others

    1998-01-01

    Under DOE/ERIP funds were made available to Superkinetic, Inc. for the development of an improved radiant burner material. Three single crystal ceramic fibers were produced and two fiber materials were made into felt for testing as radiant burner screens. The materials were alpha alumina and alpha silicon nitride. These fibers were bonded with a high temperature ceramic and made into a structurally sound trusswork like screen composed of million psi fiber members. These screens were about 5% solid for 95 porosity as needed to permit the flow of combustable natural gas and air mixture. Combustion test proved that they performed very satisfactory and better than the current state of art screen and showed no visable degrade after testing. It is recommended that more time and money be put into expanding this technology and test these new materials for their maximum temperature and durability for production applications that require better burner material.

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

    Science.gov (United States)

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

  19. Arrangement of burner with sheath tube

    Energy Technology Data Exchange (ETDEWEB)

    Graat, J.W.; Remie, H.T.; Verhagen, A.M.

    1980-10-02

    This is concerned with an addition to the burner described in patent 28 28 319 in which fluid pulverised fuel and air is burnt in a chamber. The additional patent concerns a sheath tube, which surrounds the chamber and conducts the burnt gases on. The sheath tube has openings for better guidance of the thermal flow.

  20. FLARE FLAME INSTABILITY AND BURNER COMBUSTION CONTROL

    OpenAIRE

    БОНДАРЕНКО А.В.; В. Э. Волков; Максимов, М. В.

    2014-01-01

    Research of the flare instability development and the laminar-to-turbulent transition for the flares was executed. It was proved that the effects of viscosity and compressibility have the stabilizing influence on the gas flame. The study of the individual flare stability makes the theoretical basis of the fuel burning technology in combustion chambers and for the burner combustion control.

  1. Regenerative Burner System for Thermoelectric Power Sources.

    Science.gov (United States)

    1979-07-01

    wy aid id.nt lfy by block nsaib.r) • k’ all and (or • Thermoelectric ~t special Regenerative Burner Power Sources - 20. AS TRACT (Contlnu. on r...ELECTRIC POWER SOURCES C. Cuazgo~t , J. Angello, & A. Rerchshow.ki Power Source. Division US Army Electronic. Technology and Devices Laboratory

  2. Characterizing Particle Combustion in a Rijke Burner.

    Science.gov (United States)

    1987-05-29

    Rijke Burner. rp = NU In( I + BT) PgpCpgdp 3.2 Shrinking Core Model -, Levenspiel (1972) outlines the shrinking core model. In this model the particle...M. E., Numerical Methods and Modeling for Chemical Engineers. John Wiley and Sons (1984) Levenspiel , 0., Chemical Reaction Engineering Second

  3. Market assessment for the fan atomized oil burner

    Energy Technology Data Exchange (ETDEWEB)

    Westphalen, D. [A.D. Little, Inc., Cambridge, MA (United States)

    1996-07-01

    The market potential for the fan atomized burner (FAB) in water and space heating applications was examined. The major findings of the study are as follows. (1). The FAB`s low-input capability allows development of oil-fired room heaters and wall furnaces, a new market area for oil heat. (2). Among conventional oil-fired products, furnaces will benefit most from the burner`s low input capability due to (1) their quick delivery of heat and (2) their more prevalent use in warmer climates and smaller homes. (3). The greatest potential for increased product sales or oil sales exists in the use of the burner with new products (i.e., room heaters). Sales of boilers and direct-fired water heaters are not likely to increase with the use of the burner. (4). Acceptance of the burner will be dependent on proof of reliability. Proof of better reliability than conventional burners would accelerate acceptance.

  4. Catalytic burners in larger boiler appliances

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-02-15

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

  5. Refinery burner simulation design architecture summary.

    Energy Technology Data Exchange (ETDEWEB)

    Pollock, Guylaine M.; McDonald, Michael James; Halbgewachs, Ronald D.

    2011-10-01

    This report describes the architectural design for a high fidelity simulation of a refinery and refinery burner, including demonstrations of impacts to the refinery if errors occur during the refinery process. The refinery burner model and simulation are a part of the capabilities within the Sandia National Laboratories Virtual Control System Environment (VCSE). Three components comprise the simulation: HMIs developed with commercial SCADA software, a PLC controller, and visualization software. All of these components run on different machines. This design, documented after the simulation development, incorporates aspects not traditionally seen in an architectural design, but that were utilized in this particular demonstration development. Key to the success of this model development and presented in this report are the concepts of the multiple aspects of model design and development that must be considered to capture the necessary model representation fidelity of the physical systems.

  6. Arrangement of burners for nearly stochiometric combustion

    Energy Technology Data Exchange (ETDEWEB)

    Graat, J.W.; Remie, H.T.; Verhagen, A.M.

    1980-10-02

    This is concerned with an improvement of the burners described in patent 28 28 319, where a fluid fuel which can be ground into powder and air are taken together. In order to produce correct ignition with nearly stochiometric composition of the mixture, it is proposed that a heatable body, preferably a wire spiral or ignition spiral should be used. Various variants of the shape of the heating body are discussed.

  7. PULSE DRYING EXPERIMENT AND BURNER CONSTRUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Robert States

    2006-07-15

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

  8. Field testing the prototype BNL fan-atomized oil burner

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, R.; Celebi, Y. [Brookhaven National Lab., Upton, NY (United States)

    1995-04-01

    BNL has developed a new oil burner design referred to as the Fan Atomized burner System. The primary objective of the field study was to evaluate and demonstrate the reliable operation of the Fan Atomized Burner. The secondary objective was to establish and validate the ability of a low firing rate burner (0.3-0.4 gph) to fully satisfy the heating and domestic hot water load demands of an average household in a climate zone with over 5,000 heating-degree-days. The field activity was also used to evaluate the practicality of side-wall venting with the Fan Atomized Burner with a low stack temperature (300F) and illustrate the potential for very high efficiency with an integrated heating system approach based on the Fan Atomized Burner.

  9. Furnaces with multiple flameless combustion burners

    NARCIS (Netherlands)

    Danon, B.

    2011-01-01

    In this thesis three different combustion systems, equipped with either a single or multiple flameless combustion burner(s), are discussed. All these setups were investigated both experimentally and numerically, i.e., using Computational Fluid Dynamics (CFD) simulations. Flameless combustion is a com

  10. 0. 20-m (8-in. ) primary burner development report

    Energy Technology Data Exchange (ETDEWEB)

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

    1977-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-02-15

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

  12. Les blogs

    OpenAIRE

    Angé, Caroline; Bigey, Magali; Broudoux, Évelyne; Candel, Étienne; Chapelain, Brigitte; Couleau, Christèle; Deseilligny, Oriane; di Rosario, Giovanna; Escolin-Contensou, Isabelle; Gefen, Alexandre; Hellégouarc’h, Pascale; Jeanne-Perrier, Valérie; Labbé, Mathilde; Massip, Bernard; Paloque-Berges, Camille

    2014-01-01

    Parler de genre à propos des blogs, c’est moins chercher à découvrir une espèce littéraire nouvelle dans ce corpus hétérogène et massif que tenter de définir, au-delà des spécifications techniques et fonctionnelles, un objet esthétique. Le blog s’écrit contre les genres existants, mais en porte l’empreinte autant qu’il en déplace les lignes. Il invente aussi ses usages, ses communautés, ses configurations poétiques – autant de caractéristiques par lesquelles il fait genre. Les déclinaisons mu...

  13. Fan Atomized Burner design advances & commercial development progress

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, B. [Heat-Wise, Inc., Ridge, NY (United States); Butcher, T.A. [Brookhaven National Lab., Upton, NY (United States)

    1996-07-01

    As a part of the Oil Heat Research and Development program, sponsored by the US Department of Energy, Brookhaven National Laboratory (BNL) has an on-going interest in advanced combustion technologies. This interest is aimed at: improving the initial efficiency of heating equipment, reducing long term fouling and efficiency degradation, reducing air pollutant emissions, and providing practical low-firing rate technologies which may lead to new, high efficiency oil-fired appliances. The Fan-Atomized Burner (FAB) technology is being developed at BNL as part of this general goal. The Fan-Atomized Burner uses a low pressure, air atomizing nozzle in place of the high pressure nozzle used in conventional burners. Because it is air-atomized the burner can operate at low firing rates without the small passages and reliability concerns of low input pressure nozzles. Because it uses a low pressure nozzle the burner can use a fan in place of the small compressor used in other air-atomized burner designs. High initial efficiency of heating equipment is achieved because the burner can operate at very low excess air levels. These low excess air levels also reduce the formation of sulfuric acid in flames. Sulfuric acid is responsible for scaling and fouling of heat exchanger surfaces.

  14. Les aciers inoxydables dans les fixations

    CERN Document Server

    CETIM

    2010-01-01

    Cet ouvrage, qui fait la synthèse de plusieurs travaux menés par le Cetim, propose une vue d'ensemble sur les aciers inoxydables utilisés pour les fixations. Au sommaire : les normes EN, ISO et ATSM qui s'y rapportent , les désignations symboliques , les nuances et caractéristiques mécaniques , les différentes formes de corrosion, les méthodes pour les détecter , les règles du métier , les mises en oeuvre. L'ouvrage comprend plusieurs fiches matériaux et des tableaux qui présentent les équivalences entre les désignations.

  15. Intensification of heat transfer by changing the burner nozzle

    Science.gov (United States)

    DzurÅák, Róbert; Kizek, Ján; Jablonský, Gustáv

    2016-06-01

    Thermal aggregates are using burner which burns combustible mixture with an oxidizing agent, by adjustment of the burner nozzle we can achieve better conditions of combustion to intensify heat transfer at furnace space. The aim of the present paper was using a computer program Ansys Workbench to create a computer simulation which analyzes the impact of the nozzle on the shape of a flame thereby intensifies heat transfer in rotary drum furnaces and radiation heat transfer from the flue gas into the furnace space. Article contains analysis of the geometry of the burner for achieving temperature field in a rotary drum furnace using oxy-combustion and the practical results of computer simulations

  16. Computational fluid dynamics analysis of a synthesis gas turbulent combustion in a round jet burner

    Science.gov (United States)

    Mansourian, Mohammad; Kamali, Reza

    2017-05-01

    In this study, the RNG-Large Eddy Simulation (RNG-LES) methodology of a synthesis gas turbulent combustion in a round jet burner is investigated, using OpenFoam package. In this regard, the extended EDC extinction model of Aminian et al. for coupling the reaction and turbulent flow along with various reaction kinetics mechanisms such as Skeletal and GRI-MECH 3.0 have been utilized. To estimate precision and error accumulation, we used the Smirinov's method and the results are compared with the available experimental data under the same conditions. As a result, it was found that the GRI-3.0 reaction mechanism has the least computational error and therefore, was considered as a reference reaction mechanism. Afterwards, we investigated the influence of various working parameters including the inlet flow temperature and inlet velocity on the behavior of combustion. The results show that the maximum burner temperature and pollutant emission are affected by changing the inlet flow temperature and velocity.

  17. Firing in fluid beds and burners

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-02-01

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

  18. Assessment of PWR plutonium burners for nuclear energy centers

    Energy Technology Data Exchange (ETDEWEB)

    Frankel, A J; Shapiro, N L

    1976-06-01

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

  19. Study of a ceramic burner for shaftless stoves

    Institute of Scientific and Technical Information of China (English)

    Fang-qin Dai; Suo-yi Huang; Shao-hua Li; Ke Liu

    2009-01-01

    A multi-burner-port annular flameless ceramic burner (MAFCB) of the shaftless stove for blast furnaces was designed.The characteristics of pressure drop, homogeneousness of the flows at burner ports, and distribution of the flows in the chambers and joint were studied by cold model experiments.This type of ceramic burner was successfully applied in 6# blast furnace at Liuzhou Iron & Steel Co.Ltd.(LISC) and this practice proved that it could be used in the hot blast stove and other stoves with a higher effi-ciency and a higher steadiness of hot blast temperature at 1200℃.With the combustion of blast furnace gas alone, the thermal effi- ciency was up to 78.95%, saving energy remarkably.

  20. Sensors and methods for control of modulating burners

    Energy Technology Data Exchange (ETDEWEB)

    Michel, J.-B.; Neumann, V.; Theurillat, P. [Centre Suisse d' Electronique et de Microtechnique, Neuchatel (Switzerland); Abu-Sharekh, Y. [Erlangen-Nuremberg Univ. (Germany). LSTM

    2003-07-01

    In recent years, many interesting developments have taken place for an improved control of domestic burners, with an emphasis on modulating gas and oil burners. These relate to new types of sensors for the control of excess air and to new methods and tools for the implantation of control systems on micro-controllers. These developments are reviewed and the application to the Bioflam domestic boiler is described. (orig.)

  1. Design and characterization of a linear Hencken-type burner

    Science.gov (United States)

    Campbell, M. F.; Bohlin, G. A.; Schrader, P. E.; Bambha, R. P.; Kliewer, C. J.; Johansson, K. O.; Michelsen, H. A.

    2016-11-01

    We have designed and constructed a Hencken-type burner that produces a 38-mm-long linear laminar partially premixed co-flow diffusion flame. This burner was designed to produce a linear flame for studies of soot chemistry, combining the benefit of the conventional Hencken burner's laminar flames with the advantage of the slot burner's geometry for optical measurements requiring a long interaction distance. It is suitable for measurements using optical imaging diagnostics, line-of-sight optical techniques, or off-axis optical-scattering methods requiring either a long or short path length through the flame. This paper presents details of the design and operation of this new burner. We also provide characterization information for flames produced by this burner, including relative flow-field velocities obtained using hot-wire anemometry, temperatures along the centerline extracted using direct one-dimensional coherent Raman imaging, soot volume fractions along the centerline obtained using laser-induced incandescence and laser extinction, and transmission electron microscopy images of soot thermophoretically sampled from the flame.

  2. Design and characterization of a linear Hencken-type burner.

    Science.gov (United States)

    Campbell, M F; Bohlin, G A; Schrader, P E; Bambha, R P; Kliewer, C J; Johansson, K O; Michelsen, H A

    2016-11-01

    We have designed and constructed a Hencken-type burner that produces a 38-mm-long linear laminar partially premixed co-flow diffusion flame. This burner was designed to produce a linear flame for studies of soot chemistry, combining the benefit of the conventional Hencken burner's laminar flames with the advantage of the slot burner's geometry for optical measurements requiring a long interaction distance. It is suitable for measurements using optical imaging diagnostics, line-of-sight optical techniques, or off-axis optical-scattering methods requiring either a long or short path length through the flame. This paper presents details of the design and operation of this new burner. We also provide characterization information for flames produced by this burner, including relative flow-field velocities obtained using hot-wire anemometry, temperatures along the centerline extracted using direct one-dimensional coherent Raman imaging, soot volume fractions along the centerline obtained using laser-induced incandescence and laser extinction, and transmission electron microscopy images of soot thermophoretically sampled from the flame.

  3. Advanced burner test reactor preconceptual design report.

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-12-16

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

  4. Flashback Analysis in Tangential Swirl Burners

    Directory of Open Access Journals (Sweden)

    Valera-Medina A.

    2011-10-01

    Full Text Available Premixed lean combustion is widely used in Combustion Processes due to the benefits of good flame stability and blowoff limits coupled with low NOx emissions. However, the use of novel fuels and complex flows have increased the concern about flashback, especially for the use of syngas and highly hydrogen enriched blends. Thus, this paper describes a combined practical and numerical approach to study the phenomenon in order to reduce the effect of flashback in a pilot scale 100 kW tangential swirl burner. Natural gas is used to establish the baseline results and effects of different parameters changes. The flashback phenomenon is studied with the use of high speed photography. The use of a central fuel injector demonstrates substantial benefits in terms of flashback resistance, eliminating coherent structures that may appear in the flow channels. The critical boundary velocity gradient is used for characterization, both via the original Lewis and von Elbe formula and via analysis using CFD and investigation of boundary layer conditions in the flame front.

  5. Automatic burner adjustment in a singeing oven

    Energy Technology Data Exchange (ETDEWEB)

    Aabo, P.

    1984-07-01

    The expected energy savings of 10-15% of the actual fuel consumption in the singeing oven was reduced because of the change in the design of the singeing oven itself. The socalled optimized singeing oven hereafter includes: ceramic fibres, combustion air from the ceiling, fireproof oven bottom, automatic adjustment of air and fuel, rapid opening and closing, change over to pilot flame during stops and the slaughter line, and sealing between the oven's two parts and bottom. This optimization of the design of the singeing oven reduces the oil consumption from 0.8 litre to 0.45 litre fuel per pig carcass. The described optimization of the oven is partly carried out during this project. Thus the starting point for further reduction of the energy consumption is changed rather much. Neverthless a calculation of prospective profits proves that it is still profitable to invest in equipment for adjusting the burner in the singeing oven. It has been proved that the degree of singeing can be controlled by the parameters singeing period and oven temperature. A control device for controlling of the oil consumption on the basis of the temperature of the waste gas has succesfully been installed and it has been proved that the pay back period for this control device is approximately 2 years.

  6. Enhanced Combustion Low NOx Pulverized Coal Burner

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-06-30

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

  7. Les choses…

    Directory of Open Access Journals (Sweden)

    Pierre Curie

    2012-05-01

    Full Text Available Dans la culture tant des Monuments historiques que de l’Université française, le monumental a longtemps prévalu sur l’objet, peinture, sculpture ou objet d’art qui, lui, dans l’inconscient collectif, relevait tout naturellement du musée. Dans la pensée et dans les goûts d’André Chastel, les catégories n’étaient pas aussi manichéennes et à l’Inventaire, malgré une certaine prééminence de l’architecture, l’objet - au sens large - tint, dès le début de l’aventure, une place non négligeable. Le premier des Vocabulaires parus, en 1969, fut consacré à la tapisserie, suivi, en une vingtaine d’années, par la sculpture, les objets et le mobilier civil domestique, le vitrail…In the culture of France’s historic monuments, as in French universities, the monumental has long been considered as more important than sculptures or works of art, generally seen as more to do with museums. In the writings and tastes of André Chastel, however, the categories were not so clear-cut and, at the French Inventory, although architecture has enjoyed a certain pre-eminence, the object, in the broadest sense of the term, has been taken into consideration form the outset. Over 17,000 items now feature in the national database Palissy, on moveable objects. The first scientific vocabulary, published by the Inventory services in 1969, was devoted to tapestry and, over the last twenty years, other vocabularies have dealt with sculpture, domestic civil furniture and stained glass.

  8. Les incommensurables

    CERN Document Server

    Houdart, Sophie

    2015-01-01

    Le Large Hadron Collider, ou grand collisionneur de hadrons, est l'accélérateur de particules le plus grand et le plus puissant du monde. Prenant la forme d'un anneau de 26,659 kilomètres de circonférence, lové 100 mètres sous terre et officiellement domicilié à Meyrin, à la frontière de la France et de la Suisse, il est constitué d'aimants supraconducteurs et de structures accélératrices qui augmentent l'énergie des particules qui y circulent. Chaque jour, à l'intérieur de l'accélérateur, deux faisceaux de particules qui circulent en sens contraire à des énergies très élevées avant de rentrer en collision l'un avec l'autre. Les particules, lancées à 99,9999991 % de la vitesse de la lumière, effectuent 11245 fois le tour de l'accélérateur par seconde et entrent en collision quelque 600 millions de fois par seconde. Les Incommensurables est une minutieuse enquête de terrain sur cette "cathédrale" enfouie qui offre la possibilité de se connecter à l'immensité et aux mystères de...

  9. OPTIMIZATION OF COAL PARTICLE FLOW PATTERNS IN LOW NOX BURNERS

    Energy Technology Data Exchange (ETDEWEB)

    Jost O.L. Wendt; Gregory E. Ogden; Jennifer Sinclair; Stephanus Budilarto

    2001-09-04

    It is well understood that the stability of axial diffusion flames is dependent on the mixing behavior of the fuel and combustion air streams. Combustion aerodynamic texts typically describe flame stability and transitions from laminar diffusion flames to fully developed turbulent flames as a function of increasing jet velocity. Turbulent diffusion flame stability is greatly influenced by recirculation eddies that transport hot combustion gases back to the burner nozzle. This recirculation enhances mixing and heats the incoming gas streams. Models describing these recirculation eddies utilize conservation of momentum and mass assumptions. Increasing the mass flow rate of either fuel or combustion air increases both the jet velocity and momentum for a fixed burner configuration. Thus, differentiating between gas velocity and momentum is important when evaluating flame stability under various operating conditions. The research efforts described herein are part of an ongoing project directed at evaluating the effect of flame aerodynamics on NO{sub x} emissions from coal fired burners in a systematic manner. This research includes both experimental and modeling efforts being performed at the University of Arizona in collaboration with Purdue University. The objective of this effort is to develop rational design tools for optimizing low NO{sub x} burners. Experimental studies include both cold-and hot-flow evaluations of the following parameters: primary and secondary inlet air velocity, coal concentration in the primary air, coal particle size distribution and flame holder geometry. Hot-flow experiments will also evaluate the effect of wall temperature on burner performance.

  10. Advanced Burner Reactor Preliminary NEPA Data Study.

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, L. L.; Cahalan, J. E.; Deitrich, L. W.; Fanning, T. H.; Grandy, C.; Kellogg, R.; Kim, T. K.; Yang, W. S.; Nuclear Engineering Division

    2007-10-15

    The Global Nuclear Energy Partnership (GNEP) is a new nuclear fuel cycle paradigm with the goals of expanding the use of nuclear power both domestically and internationally, addressing nuclear waste management concerns, and promoting nonproliferation. A key aspect of this program is fast reactor transmutation, in which transuranics recovered from light water reactor spent fuel are to be recycled to create fast reactor transmutation fuels. The benefits of these fuels are to be demonstrated in an Advanced Burner Reactor (ABR), which will provide a representative environment for recycle fuel testing, safety testing, and modern fast reactor design and safeguard features. Because the GNEP programs will require facilities which may have an impact upon the environment within the meaning of the National Environmental Policy Act of 1969 (NEPA), preparation of a Programmatic Environmental Impact Statement (PEIS) for GNEP is being undertaken by Tetra Tech, Inc. The PEIS will include a section on the ABR. In support of the PEIS, the Nuclear Engineering Division of Argonne National Laboratory has been asked to provide a description of the ABR alternative, including graphics, plus estimates of construction and operations data for an ABR plant. The compilation of this information is presented in the remainder of this report. Currently, DOE has started the process of engaging industry on the design of an Advanced Burner Reactor. Therefore, there is no specific, current, vendor-produced ABR design that could be used for this PEIS datacall package. In addition, candidate sites for the ABR vary widely as to available water, geography, etc. Therefore, ANL has based its estimates for construction and operations data largely on generalization of available information from existing plants and from the environmental report assembled for the Clinch River Breeder Reactor Plant (CRBRP) design [CRBRP, 1977]. The CRBRP environmental report was chosen as a resource because it thoroughly

  11. Les expositions

    OpenAIRE

    2016-01-01

    Liré Musée Joachim Du Bellay. Jeux et divertissements à la Renaissance Depuis le vernissage du samedi 26 avril 2008 et jusqu’au 31 octobre 2008, l’exposition Jeux et divertissements à la Renaissance a été proposée au public par le Musée. Des panneaux expliquaient et illustraient les amusements de la Renaissance : danses, théâtre, jeux de sociétés, fêtes, tournois, jeu de paume… Des jeux étaient à disposition pour tester ses connaissances, s’essayer aux jeux de sociétés ou d’adresse de l’époqu...

  12. Compact Green's Function for a Generic Rijke Burner

    Directory of Open Access Journals (Sweden)

    P. R. Murray

    2011-09-01

    Full Text Available A theoretical examination is made of the thermo-acoustic properties of a Rijke burner of large aspect ratio rectangular cross-section. Such a generic device has been proposed by Kok et al. (2009 paper presented at the 16th International Congress on Sound & Vibration to make canonical studies of combustion instabilities. An aeroacoustic Green's function is derived which permits the sound pressure produced by arbitrary thermal and vortex sources within the burner to be calculated by convolution. The Green's function corresponds to the potential flow sound field produced by an impulsive point source; its calculation taking account of flame-holder geometry is facilitated by use of the Schwarz-Christoffel transformation. The transformation is performed numerically to accommodate complex burner geometry and validated by comparison with an alternative procedure involving the direct numerical integration of Laplace's equation.

  13. 280 burners reduce NOx emissions and improve boiler performance at Nanticoke power station

    Energy Technology Data Exchange (ETDEWEB)

    Burpee, J.; Tigges, K.-D.; Baehner, J. [Ontario Power Generation, Inc. (Canada)

    1999-07-01

    Describes work undertaken at the Nanticoke coal-fired power station (Canada), to convert the existing burners to low NO{sub x} burners to meet NO{sub x} reduction requirements and improve boiler performance. The burners on four units have already been modified and conversion work is been carried out on three other units. 280 modified coal burners are expected to be in operation by the end of 1999. 17 figs.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-06-01

    An initial testing campaign was carried out during the summer of 2000 to evaluate the impact of multiburner firing on NOx emissions. Extensive data had been collected during the Fall of 1999 and Spring of 2000 using a single pulverized-coal (PC) burner, and this data collection was funded by a separate Department of Energy program, the Combustion 2000 Low Emission Boiler System (LEBS) project under the direction of DB Riley. This single-burner data was thus available for comparison with NOx emissions obtained while firing three burners at the same overall load and operating conditions. A range of operating conditions were explored that were compatible with single-burner data, and thus the emission trends as a function of air staging, burner swirl and other parameters will be described below. In addition, a number of burner-to-burner operational variations were explored that provided interesing insight on their potential impact on NOx emissions. Some of these variations include: running one burner very fuel rich while running the others fuel lean; varying the swirl of a single burner while holding others constant; increasing the firing rate of a single burner while decreasing the others. In general, the results to date indicated that multiburner firing yielded higher NOx emissions than single burner firing at the same fuel rate and excess air. At very fuel rich burner stoichiometries (SR < 0.75), the difference between multiple and single burners became indistinguishable. This result is consistent with previous single-burner data that showed that at very rich stoichiometries the NOx emissions became independent of burner settings such as air distributions, velocities and burner swirl.

  15. Mathematical Model of Combustion in Blunt Annular Ceramic Burner

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The computer simulation of the combustion process in blast furnace (BF) stove has been studied by using the k-ε-g turbulent diffusion flame model. The combustion process in blunt annular ceramic burner was calculated by using the software. The profiles of gas and air velocity, temperature of the combustion products, concentration of the components, and the shape and length of the flame during combustion have been researched . Compared with the original annular ceramic burner, the new design of the blunt one improves the mixing of the gas and the air significantly, and shortened the length of the flame.

  16. Arrangement of burner without pump with subsequent sheath tube

    Energy Technology Data Exchange (ETDEWEB)

    Graat, J.W.; Remie, H.T.; Verhagen, A.M.

    1980-10-02

    The burner described in main patent 2828319 is operated with fluid pulverised fuel and air. The additional patent concerns a sheath tube, which surrounds the combustion chamber and conducts the hot gases on. Flow guide elements, e.g. a cylindrical guide sleeve, are installed in the sheath tube to improve the guidance of the thermal flow.

  17. 30 CFR 57.7803 - Lighting the burner.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Lighting the burner. 57.7803 Section 57.7803 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and...

  18. 30 CFR 56.7803 - Lighting the burner.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Lighting the burner. 56.7803 Section 56.7803 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary...

  19. Camping Burner-Based Flame Emission Spectrometer for Classroom Demonstrations

    Science.gov (United States)

    Ne´el, Bastien; Crespo, Gasto´n A.; Perret, Didier; Cherubini, Thomas; Bakker, Eric

    2014-01-01

    A flame emission spectrometer was built in-house for the purpose of introducing this analytical technique to students at the high school level. The aqueous sample is sprayed through a homemade nebulizer into the air inlet of a consumer-grade propane camping burner. The resulting flame is analyzed by a commercial array spectrometer for the visible…

  20. The generation of resonant turbulence for a premixed burner

    NARCIS (Netherlands)

    Verbeek, A.A.; Pos, R.C.; Stoffels, G.G.M.; Geurts, B.J.; Meer, van der Th.H.

    2012-01-01

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

  1. A burner for plasma-coal starting of a boiler

    Science.gov (United States)

    Peregudov, V. S.

    2008-04-01

    Advanced schemes of a plasma-coal burner with single-and two-stage chambers for thermochemical preparation of fuel are described. The factors causing it becoming contaminated with slag during oil-free starting of a boiler are considered, and methods for preventing this phenomenon are pointed out.

  2. A burner for plasma-coal starting of a boiler

    Energy Technology Data Exchange (ETDEWEB)

    V.S. Peregudov [Kutateladze Institute of Thermal Physics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2008-04-15

    Advanced schemes of a plasma-coal burner with single-and two-stage chambers for thermochemical preparation of fuel are described. The factors causing it becoming contaminated with slag during oil-free starting of a boiler are considered, and methods for preventing this phenomenon are pointed out.

  3. Gap flow burners in industrial applications; Spaltstrombrenner im industriellen Einsatz

    Energy Technology Data Exchange (ETDEWEB)

    Wuenning, Joachim G. [WS Waermeprozesstechnik GmbH, Renningen (Germany)

    2013-02-15

    Gaseous fuels are usually the most economical and ecological source of energy for heating industrial furnaces. However, it is always possible to further increase efficiency and lower emissions. The introduction of new burner systems requires a close cooperation with furnace makers and operators to ensure success of the new products. (orig.)

  4. [Burner head with high sensitivity in atomic absorption spectroscopy].

    Science.gov (United States)

    Feng, X; Yang, Y

    1998-12-01

    This paper presents a burner head with gas-sample separate entrance and double access, which is used for atomic absorption spectroscopy. According to comparison and detection, the device can improve sensitivity by a factor of 1 to 5. In the meantime it has properties of high stability and resistance to interference.

  5. Oxyhydrogen burner for low-temperature flame fusion

    Science.gov (United States)

    Ueltzen, M.; Brüggenkamp, T.; Franke, M.; Altenburg, H.

    1993-04-01

    An oxyhydrogen burner as described in this article enables the growth of crystals by Verneuil's technique at temperatures of about 1000 °C. The powder fed to the crystal passes along a low-temperature pathway through the flame, so that evaporation of volatile components is prevented. Low-temperature flame fusion of superconducting Y-Ba-cuprate is reported.

  6. Study of the Effects of Ambient Conditions Upon the Performance of Fan Powered, Infrared Natural Gas Burners

    Energy Technology Data Exchange (ETDEWEB)

    Clark Atlanta University

    2002-12-02

    The objective of this investigation was to characterize the operation of a fan-powered, infrared burner (IR burner) at various gas compositions and ambient conditions, develop numerical model to simulate the burner performances, and provide design guidelines for appliances containing PIR burners for satisfactory performance.

  7. VARIABLE FIRING RATE OIL BURNER USING PULSE FUEL FLOW CONTROL.

    Energy Technology Data Exchange (ETDEWEB)

    KRISHNA,C.R.; BUTCHER,T.A.; KAMATH,B.R.

    2004-10-01

    The residential oil burner market is currently dominated by the pressure-atomized retention head burner, which has an excellent reputation for reliability and efficiency. In this burner, oil is delivered to a fuel nozzle at pressures from 100 to 150 psi. In addition, to atomizing the fuel, the small, carefully controlled size of the nozzle exit orifice serves to control the burner firing rate. Burners of this type are currently available at firing rates of more than 0.5 gallons-per-hour (70,000 Btu/hr). Nozzles have been made for lower firing rates, but experience has shown that such nozzles suffer rapid fouling of the necessarily small passages, leading to bad spray patterns and poor combustion performance. Also, traditionally burners and the nozzles are oversized to exceed the maximum demand. Typically, this is figured as follows. The heating load of the house on the coldest day for the location is considered to define the maximum heat load. The contractor or installer adds to this to provide a safety margin and for future expansion of the house. If the unit is a boiler that provides domestic hot water through the use of a tankless heating coil, the burner capacity is further increased. On the contrary, for a majority of the time, the heating system is satisfying a much smaller load, as only rarely do all these demands add up. Consequently, the average output of the heating system has to be much less than the design capacity and this is accomplished by start and stop cycling operation of the system so that the time-averaged output equals the demand. However, this has been demonstrated to lead to overall efficiencies lower than the steady-state efficiency. Therefore, the two main reasons for the current practice of using oil burners much larger than necessary for space heating are the unavailability of reliable low firing rate oil burners and the desire to assure adequate input rate for short duration, high draw domestic hot water loads. One approach to solve this

  8. USE OF GAS BURNERS TYPE "DAVA" OPERATING UNDER VARIABLE LOAD TO PRODUCE HEAT AND HOT WATER

    Directory of Open Access Journals (Sweden)

    Daud V.

    2014-12-01

    Full Text Available The article brings additional information referred to upgraded gas burners type "DAVA", which are characterized by high performance at variable load. Adaptation of burner operation is carried out automatically. There are presented design features that allow increase of the efficiency and the reliability of these burners at variable load, and reducing natural gas consumption. The range of variation of the coefficient of excess air affects the efficiency of the burner. The experimental results of the tests of gas burners of different power had confirmed the economic effect of the upgraded burners at heat production. It is proved that economic effect increases with increasing of burner output and of operation time during the season.

  9. Equipment for biomass. Wood burners; Materiels pour la biomasse, les chaudieres bois

    Energy Technology Data Exchange (ETDEWEB)

    Chieze, B. [SA Compte R., 63 - Arlanc (France)

    1997-12-31

    A review of the French classification of biomass wastes (and more especially wood and wood wastes) concerning classified burning equipment, is presented: special authorization is thus needed for burning residues from wood second transformation processes. Limits for combustion product emission levels are detailed and their impact on wood burning and process equipment is examined: feeder, combustion chamber, exchanger, fume treatment device, residue disposal. Means for reducing pollutant emissions are reviewed

  10. LES SOFTWARE FOR THE DESIGN OF LOW EMISSION COMBUSTION SYSTEMS FOR VISION 21 PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    Clifford Smith

    2003-09-01

    Application and testing of the new combustion Large Eddy Simulation (LES) code for the design of advanced gaseous combustion systems is described in this 12th quarterly report. In this quarter, continued validation and testing of the combustion LES code was performed for the DOE-SimVal combustor. Also, beta testing by six consortium members was performed for various burner and combustor configurations. A list of suggested code improvements by the beta testers was itemized. Work will continue in FY04. A conditional modification to the contract will be granted. The additional work will focus on modeling/analyzing the SimVal experiments.

  11. Comment les jeunes gens utilisent les cartes

    Directory of Open Access Journals (Sweden)

    H. Sandford

    1990-09-01

    Full Text Available Des recherches sur l’utilisation des cartes dans les collèges et les lycées révèlent une hiérarchie de procédés qui met au jour des lacunes dans la formation au niveau secondaire.

  12. Visualization of flashback in a premixed burner with swirling flow

    Institute of Scientific and Technical Information of China (English)

    Satoshi; TANIMURA; Masaharu; KOMIYAMA; Kenichiro; TAKEISHI; Yuji; IWASAKI; Kiyonobu; NAKAYAMA

    2010-01-01

    In this study,the measurement object is a flame propagating in a premixed burner with swirling flow in order to investigate unsteady flame behavior in a gas turbine premixer.During flashback,the flame propagating upstream was visualized with a high-speed camera.Moreover,we established the technique to measure the instantaneous flow fields of unburned fuel-air mixture in a swirling premixed burner using particle image velocimetry(PIV).As a result,the characteristics of flame behavior propagating upstream were examined.And it was found that a low velocity region existed in the vicinity of the flame tip.The relationship between low velocity region and flame behavior was discussed in detail.

  13. Low Acoustic Impact Burner; Combustore a basso impatto acustico

    Energy Technology Data Exchange (ETDEWEB)

    Bartolini, C.M.; Cesini, G.; Mattei, E.; Salvi, D. [Ancona Univ., Ancona (Italy). Dipt. di Energetica; Sesterzi, M. [Accorroni S.r.l., Osimo, AN (Italy)

    2000-03-01

    The combustion process in some gas burners generates low frequency vibrations which cause sound energy; in order to reducing those acoustic emissions all the releasing sources of the unit have been analysed, choosing to operate directly upon the combustion process. The combustion noise has been reduced of 7.5 dB, with an increase in the number of the burner's releasing sources, keeping constant engaged thermal power. [Italian] Il processo di combustione che avviene in alcuni bruciatori a gas genera pulsazioni a bassa frequenza che liberano energia sonora; allo scopo di ridurre tali emissioni acustiche sono state analizzate tutte le sorgenti emissive del complesso, decidendo di intervenire direttamente sul processo di combustione. Il rumore di combustione e' stato ridotto di 7,5 dB aumentando il numero delle sorgenti emissive del bruciatore, tenendo costante la potenza termica impegnata.

  14. OPTIMIZATION OF COAL PARTICLE FLOW PATTERNS IN LOW NOX BURNERS

    Energy Technology Data Exchange (ETDEWEB)

    Jost O.L. Wendt; Gregory E. Ogden; Jennifer Sinclair; Caner Yurteri

    2001-08-20

    The proposed research is directed at evaluating the effect of flame aerodynamics on NO{sub x} emissions from coal fired burners in a systematic manner. This fundamental research includes both experimental and modeling efforts being performed at the University of Arizona in collaboration with Purdue University. The objective of this effort is to develop rational design tools for optimizing low NO{sub x} burners to the kinetic emissions limit (below 0.2 lb./MMBTU). Experimental studies include both cold and hot flow evaluations of the following parameters: flame holder geometry, secondary air swirl, primary and secondary inlet air velocity, coal concentration in the primary air and coal particle size distribution. Hot flow experiments will also evaluate the effect of wall temperature on burner performance. Cold flow studies will be conducted with surrogate particles as well as pulverized coal. The cold flow furnace will be similar in size and geometry to the hot-flow furnace but will be designed to use a laser Doppler velocimeter/phase Doppler particle size analyzer. The results of these studies will be used to predict particle trajectories in the hot-flow furnace as well as to estimate the effect of flame holder geometry on furnace flow field. The hot-flow experiments will be conducted in a novel near-flame down-flow pulverized coal furnace. The furnace will be equipped with externally heated walls. Both reactors will be sized to minimize wall effects on particle flow fields. The cold-flow results will be compared with Fluent computation fluid dynamics model predictions and correlated with the hot-flow results with the overall goal of providing insight for novel low NO{sub x} burner geometry's.

  15. Controversy of the year. Biomedical ethics on the front burner.

    Science.gov (United States)

    2000-12-22

    CONTROVERSY OF THE YEAR: Biomedical Ethics on the Front Burner It was a hot year for debates over research ethics. Controversy erupted in late 1999 after the death of 18-year-old Jesse Gelsinger in a gene-therapy clinical trial at the University of Pennsylvania. Because Penn and one of its clinicians had a financial stake in a gene-therapy company, questions about potential conflicts of interest arose at once.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-11-15

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

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

    Directory of Open Access Journals (Sweden)

    K. F. Mustafa

    2015-01-01

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

  18. Cathlean: catalytic, hybrid, lean-premixed burner for gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Carroni, Richard; Griffin, Timothy [Alstom Power Technology Ltd., Baden-Daettwil (Switzerland); Kelsall, Greg [Alstom Power Technology Centre, Whetstone (United Kingdom)

    2004-08-01

    Cathlean (an EU FP5 project) addresses the research and development of an advanced, ultra-low NO{sub x}, hybrid burner for gas turbines (present and future), that combines catalytic and lean-premix combustion components. Such a hybrid design enables this new technology to be introduced in a lower-risk manner. The catalytic elements serve to pretreat the fuel in order to enhance performance in terms of emissions <3 ppmv NO{sub x} and <10 ppmv CO at 15% O{sub 2} and 50-100% load, for natural gas fuel), part-load stability (reducing the lean blow-out temperature by over 100 deg C) and thermoacoustic phenomena (pulsations << 0.3% of pressure). The principle scientific objective is to quantify the advantages of the hybrid burner in terms of the above-mentioned criteria, relative to traditional, lean-premixed combustors. The present paper describes the technical and organisational aspects of the project, including an outline of state-of-the-art catalytic combustion technology, technical specification of the advanced burner and a description of the methods used to attain project goals. (Author)

  19. The BNL fan-atomized burner system prototype

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, T.A.; Celebi, Y. [Brookhaven National Lab., Upton, NY (United States)

    1995-04-01

    Brookhaven National Laboratory (BNL) has a continuing interest in the development of advanced oil burners which can provide new capabilities not currently available with pressure atomized, retention head burners. Specifically program goals include: the ability to operate at firing rates as low as 0.25 gph; the ability to operate with very low excess air levels for high steady state efficiency and to minimize formation of sulfuric acid and iron sulfate fouling; low emissions of smoke, CO, and NO{sub x} even at very low excess air levels; and the potential for modulation - either staged firing or continuous modulation. In addition any such advanced burner must have production costs which would be sufficiently attractive to allow commercialization. The primary motivation for all work sponsored by the US DOE is, of course, improved efficiency. With existing boiler and furnace models this can be achieved through down-firing and low excess air operation. Also, with low excess air operation fouling and efficiency degradation due to iron-sulfate scale formation are reduced.

  20. Further development of the 'Pluto'-burner; Weiterentwicklung des Pluto-Brenners (Simulationsunterstuetzung)

    Energy Technology Data Exchange (ETDEWEB)

    Baykal, S.; Gass, J.

    2004-07-01

    This well-illustrated final report for the Swiss Federal Office of Energy (SFOE) made by the Laboratory for Thermodynamics at the Federal Institute of Technology in Zurich presents the measurements made and the results obtained from tests made on the 'Pluto' burner. This burner is a low-power oil-evaporation burner with a power of 5 - 15 kW with a high potential for use as an atomizer burner in well-insulated single-family homes. The report presents a multitude of results in graphical form. The simulations carried out at the laboratory investigated the use of the burner in a condensing heating unit with top-to-bottom airflow and provided the basis for optimisation of the burner's performance and manufacturing costs.

  1. Les classiques, les modernes et nous

    Directory of Open Access Journals (Sweden)

    François Hartog

    2010-06-01

    Full Text Available Quelle est la place des études classiques aujourd'hui, qu'a-t-elle été, que peut-elle être encore? Dans la longue durée de l'histoire européenne, nous nous arrêterons sur les opérations  que le  recours aux anciens possible. Quels gestes ont-ils suscité? Quelles configurations ont été incessamment reprises, scrutées, investies et réinvesties au cours des siècles: le couple formé par les ancients et les modernes, mais aussi dans leur sillage les sauvages ou les barbares face aux civilisés, les classiques, face aux romantiquesavec des préclassiques et pui des néoclassiques...A travers leurs interrelations et leurs oppositions, se dessine, en fait, le mouvement continué de production de la culture moderne de l'Europe , où le couple des anciens et des modernes a longtemps tenus un des premiers ròles, avec sa longue histoire de "querelles"

  2. Strand Burner Results of AFP-001 Propellant with Inert Coating for Temperature Compensation

    Science.gov (United States)

    2015-10-01

    ARL-MR-0907 ● OCT 2015 US Army Research Laboratory Strand Burner Results of AFP -001 Propellant with Inert Coating for Temperature...Laboratory Strand Burner Results of AFP -001 Propellant with Inert Coating for Temperature Compensation by John J Ritter and Anthony Canami...COVERED (From - To) February 2015 4. TITLE AND SUBTITLE Strand Burner Results of AFP -001 Propellant with Inert Coating for Temperature Compensation

  3. Computational investigations of low-emission burner facilities for char gas burning in a power boiler

    Science.gov (United States)

    Roslyakov, P. V.; Morozov, I. V.; Zaychenko, M. N.; Sidorkin, V. T.

    2016-04-01

    Various variants for the structure of low-emission burner facilities, which are meant for char gas burning in an operating TP-101 boiler of the Estonia power plant, are considered. The planned increase in volumes of shale reprocessing and, correspondingly, a rise in char gas volumes cause the necessity in their cocombustion. In this connection, there was a need to develop a burner facility with a given capacity, which yields effective char gas burning with the fulfillment of reliability and environmental requirements. For this purpose, the burner structure base was based on the staging burning of fuel with the gas recirculation. As a result of the preliminary analysis of possible structure variants, three types of early well-operated burner facilities were chosen: vortex burner with the supply of recirculation gases into the secondary air, vortex burner with the baffle supply of recirculation gases between flows of the primary and secondary air, and burner facility with the vortex pilot burner. Optimum structural characteristics and operation parameters were determined using numerical experiments. These experiments using ANSYS CFX bundled software of computational hydrodynamics were carried out with simulation of mixing, ignition, and burning of char gas. Numerical experiments determined the structural and operation parameters, which gave effective char gas burning and corresponded to required environmental standard on nitrogen oxide emission, for every type of the burner facility. The burner facility for char gas burning with the pilot diffusion burner in the central part was developed and made subject to computation results. Preliminary verification nature tests on the TP-101 boiler showed that the actual content of nitrogen oxides in burner flames of char gas did not exceed a claimed concentration of 150 ppm (200 mg/m3).

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

    Energy Technology Data Exchange (ETDEWEB)

    Diezinger, S.

    2006-07-01

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

  5. Les risques du travail

    CERN Document Server

    Thébaud-Mony, Annie

    2015-01-01

    Depuis les années 1990, les conditions de travail se sont peu à peu imposées dans le débat social. Néanmoins, la situation reste critique. Les risques traditionnels n'ont pas disparu : les manutentions lourdes, l'exposition professionnelle aux cancérogènes, au bruit ou aux vibrations demeurent répandues... De plus, certaines " améliorations " n'ont fait que déplacer et dissimuler les problèmes, telle l'externalisation des risques grâce à la sous-traitance. Dans le même temps, les transformations du travail et des modalités de gestion de la main-d'œuvre ont fragilisé les collectifs et accru l'isolement des salariés, conduisant à une montée visible de la souffrance psychique. Face à ces évolutions, il est plus que jamais nécessaire que tous les acteurs concernés, en particulier les salariés eux-mêmes et leurs représentants, s'approprient les connaissances indispensables pour améliorer la protection de la santé sur les lieux du travail. Tel est le but de ce livre, qui renouvelle int�...

  6. Numerical simulation of fluid flow in a reheating furnace with multi-swirling-burners

    Institute of Scientific and Technical Information of China (English)

    Baowei Li; Zengwu Zhao; Yike Li; Wenfei Wu; Daqiang Cang

    2003-01-01

    A general numerical simulating program for three-dimensional (3-D) and time-dependent fluid flow for a reheating furnace with multi-swirling-burners has been developed based upon an arbitrary Lagrangian-Eulerian scheme (ALE) with the finite volume method. The parameters of fluid flow in a reheating furnace with multi-swirling-burners was calculated and the 3-D velocity distributions were obtained. The design of the burners was optimized for forming better swirling flow. The simulation shows that the fluid flow in the reheating furnace with the optimized burners is reasonable.

  7. Les Cahiers du CREAD

    African Journals Online (AJOL)

    Admin

    les littératures économique et gestionnaire, mais souvent dans ces travaux, l'effet de ... chiffre d'affaires du nouvel ensemble résultant de la vente des produits mieux .... syndicalisme, droit de grève), fiscales (différents taux d'imposition, etc.) .... nouvel ensemble et aussi, les différentes relations avec les alliances verticales ...

  8. Les outils du CERN

    CERN Multimedia

    1999-01-01

    C'est le plus grand centre mondial de recherche en physique des particules. Les outils du Laboratoire, accélérateurs et détecteurs de particules, figurent parmi les instruments scientifiques les plus complexes au monde. Des prix Nobels ont d'ailleurs été attribués aux physiciens du CERN pour leurs développements.

  9. Mechanisms of suppressing cup-burner flame with water vapor

    Institute of Scientific and Technical Information of China (English)

    CONG BeiHua; LIAO GuangXuan

    2008-01-01

    The mechanisms of suppressing a laminar methane-air co-flow diffusion flame formed on a cup burner with water vapor have been studied experimentally and numerically. The methane burned in a steel cup surrounded by a glass chimney. A mist generator produced fine droplets delivered though the glass chimney with air. These droplets were heated into water vapor when they went though the diffuser. The extinguishing limit was obtained by gradually increasing the amount of water vapor to replace the air in the coflowing oxidizer stream. Results showed that the agent concentration required for extinguishment was constant over a wide range of the oxidizer velocity, i.e., a so-called "plateau region". The measured extinguishing mass fractions of the agents were: (16.7±0.6)% for H2O, (15.9±0.6)% for CO2, and (31.9±0.6)% for N2. The computation used the Fire Dynamics Simulator (FDS) de-veloped by the NIST. The numerical simulations showed that the predicted water vapor extinguishing limits and the flickering frequency were in good agreements with the experimental observations and, more importantly, revealed that the sup-pression of cup-burner flames occurred via a partial extinction mechanism (in which the flame base drifts downstream and then blows off) rather than the global extinction mechanism of typical counter-flow diffusion flames. And the flame-base oscillation just before the blow-off was the key step for the non-premixed flame extinction in the cup burner.

  10. Mechanisms of suppressing cup-burner flame with water vapor

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The mechanisms of suppressing a laminar methane-air co-flow diffusion flame formed on a cup burner with water vapor have been studied experimentally and numerically. The methane burned in a steel cup surrounded by a glass chimney. A mist generator produced fine droplets delivered though the glass chimney with air. These droplets were heated into water vapor when they went though the diffuser. The extinguishing limit was obtained by gradually increasing the amount of water vapor to replace the air in the coflowing oxidizer stream. Results showed that the agent concentration required for extinguishment was constant over a wide range of the oxidizer velocity, i.e., a so-called "plateau region". The measured extinguishing mass fractions of the agents were: (16.7 ± 0.6)% for H2O, (15.9 ± 0.6)% for CO2, and (31.9 ± 0.6)% for N2. The computation used the Fire Dynamics Simulator (FDS) de- veloped by the NIST. The numerical simulations showed that the predicted water vapor extinguishing limits and the flickering frequency were in good agreements with the experimental observations and, more importantly, revealed that the sup- pression of cup-burner flames occurred via a partial extinction mechanism (in which the flame base drifts downstream and then blows off) rather than the global extinction mechanism of typical counter-flow diffusion flames. And the flame-base oscillation just before the blow-off was the key step for the non-premixed flame extinction in the cup burner.

  11. Premixed Combustion of Coconut Oil on Perforated Burner

    OpenAIRE

    I.K.G. Wirawan; I. N. G. Wardana; Rudy Soenoko; Slamet Wahyudi

    2013-01-01

    Coconut oil premixed combustion behavior has been studied experimentally on perforated burner with equivalence ratio (φ) varied from very lean until very rich. The results showed that burning of glycerol needs large number of air so that the laminar burning velocity (SL) is the highest at very lean mixture and the flame is in the form of individual Bunsen flame on each of the perforated plate hole. As φ is increased the  SL decreases and the secondary Bunsen flame with open tip occurs from φ ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Storm Pedersen, Lars

    1997-08-01

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

  13. OH Diffusion in Silica Glass Preform During Jacketing Process by Oxy-Hydrogen Burner

    Institute of Scientific and Technical Information of China (English)

    B. H. Kim; S. R. Han; U. C. Paek; W.-T. Han; S. K. Oh

    2003-01-01

    Radial distribution of OH diffusion in silica glass preform during jacketing process using a oxy-hydrogen burner was investigated by FTIR spectroscopy. The OH peaks at the jacketing boundary and the surface of the preform were found to be due to diffusion of OH incorporated from the burner.

  14. 16 CFR Figure 5 to Part 1633 - Details of Burner Stand-off

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Details of Burner Stand-off 5 Figure 5 to Part 1633 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS... of Burner Stand-off ER15MR06.004...

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

    DEFF Research Database (Denmark)

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

    1999-01-01

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

  16. Plasma-assisted combustion technology for NOx reduction in industrial burners.

    Science.gov (United States)

    Lee, Dae Hoon; Kim, Kwan-Tae; Kang, Hee Seok; Song, Young-Hoon; Park, Jae Eon

    2013-10-01

    Stronger regulations on nitrogen oxide (NOx) production have recently promoted the creation of a diverse array of technologies for NOx reduction, particularly within the combustion process, where reduction is least expensive. In this paper, we discuss a new combustion technology that can reduce NOx emissions within industrial burners to single-digit parts per million levels without employing exhaust gas recirculation or other NOx reduction mechanisms. This new technology uses a simple modification of commercial burners, such that they are able to perform plasma-assisted staged combustion without altering the outer configuration of the commercial reference burner. We embedded the first-stage combustor within the head of the commercial reference burner, where it operated as a reformer that could host a partial oxidation process, producing hydrogen-rich reformate or synthesis gas product. The resulting hydrogen-rich flow then ignited and stabilized the combustion flame apart from the burner rim. Ultimately, the enhanced mixing and removal of hot spots with a widened flame area acted as the main mechanisms of NOx reduction. Because this plasma burner acted as a low NOx burner and was able to reduce NOx by more than half compared to the commercial reference burner, this methodology offers important cost-effective possibilities for NOx reduction in industrial applications.

  17. Industrial burners with compact burner management system on industrial applications; Industriebrenner mit kompaktem Brenner-Management-System in verschiedenen industriellen Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Saenger, P.; Bloess, H. [CRONE Waermetechnik GmbH (Germany)

    2008-07-15

    Industrial burners are the heart of every thermal process-based production line. The quality of the final product depends largely on the burner's reliability and performance. Small maintenance effort and maximum availability, high energy efficiency and seamless integration into existing automation systems are the key requirements placed on advanced industrial firing systems. Whether thermal after-burning, drying or assisted firing, the scope of industrial applications demands an extensive range of solutions. Depending on individual requirements, the LMV family of burner management systems from Siemens Building Technologies (SBT) offers complete high-end solutions for the control of thermal process-based production lines reaching from metalworking to the production of glass wool, ceramics or automobiles, textiles, paper, plastics and rubber. This paper describes various burner management systems that are used on a number of different applications. (orig.)

  18. Experimental Study of Flow Field at the Outlet of Dual-Channel Burner

    Institute of Scientific and Technical Information of China (English)

    Yao Bin; Wang Hanfeng; Zeng Hancai; Jiao Qingfeng

    2005-01-01

    This paper presents an experimental study result of flow field of a dual-channel burner. In order to solve the ubiquitous problem of bad rigidity of jets in dual-channel burners, wedges with different arrangements and structural parameters were added to different positions at the outlet of the burners. Laser Particle Image Velocimetry (PIV) was used in this study to measure the flow field to investigate influence of the wedges on flow field of the dual-channel burner. Experimental study shows that fixing wedges at both right and left sides of the burner's outlet can increase the intensity of recirculation without changing the size of the recirculation zone and enhance the rigidity of jets via increasing speed of the two primary air jets at the outlet.

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

    Energy Technology Data Exchange (ETDEWEB)

    J. D. Sullivan; A. Webb

    1999-12-01

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

  20. 40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

    Science.gov (United States)

    2010-07-01

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

  1. Les Nymphes dans les rites du mariage

    OpenAIRE

    2013-01-01

    Le champ du mariage (où l’on rencontre à la fois les Nymphes puissances surnaturelles et les numphai humaines) peut se révéler intéressant pour croiser des données littéraires, archéologiques et épigraphiques sur le culte des Nymphes. Lors des préliminaires, ces puissances peuvent être l’objet des protéléia (sacrifices prénuptiaux) ou être associées avec la loutrophorie et le bain prénuptial. Les Nymphes n’interviennent guère pendant la journée de célébration du mariage, sauf dans des textes ...

  2. Visualisation of isothermal large coherent structures in a swirl burner

    Energy Technology Data Exchange (ETDEWEB)

    Valera-Medina, A.; Syred, N.; Griffiths, A. [School of Engineering, Cardiff University, Queen' s Building, The Parade, Cardiff, Wales CF24 3AA (United Kingdom)

    2009-09-15

    Lean premixed combustion using swirl flame stabilisation is widespread amongst gas turbine manufacturers. The use of swirl mixing and flame stabilisation is also prevalent in many other non-premixed systems. Problems that emerge include loss of stabilisation as a function of combustor geometry and thermo-acoustic instabilities. Coherent structures and their relationship with combustion processes have been a concern for decades due to their complex nature. This paper thus adopts an experimental approach to characterise large coherent structures in swirl burners under isothermal conditions so as to reveal the effects of swirl in a number of geometries and cold flow patterns that are relevant in combustion. Aided by techniques such as Hot Wire Anemometry, High Speed Photography and Particle Image Velocimetry, the recognition of several structures was achieved in a 100 kW swirl burner model. Several varied, interacting, structures developed in the field as a consequence of the configurations used. New structures never observed before were identified, the results not only showing the existence of very well defined large structures, but also their dependency on geometrical and flow parameters. The PVC is confirmed to be a semi-helical structure, contrary to previous simulations performed on the system. The appearance of secondary recirculation zones and suppression of the vortical core as a consequence of geometrical constrictions are presented as a mechanism of flow control. The asymmetry of the Central Recirculation Zone in cold flows is observed in all the experiments, with its elongation dependent on Re and swirl number used. (author)

  3. Advanced monitoring of industrial burners based on fluctuating flame signals

    Energy Technology Data Exchange (ETDEWEB)

    A. Sanz; J. Ballester; R. Hernandez; L.M. Cerecedo [University of Zaragoza, Zaragoza (Spain). Fluid Mechanics Group/LITEC

    2008-06-15

    The present work explores the potential of pressure and radiation sensors for the advanced monitoring/control of industrial flames. These instruments are rugged, non-intrusive and non-expensive and might be used in routine plant operation to obtain direct information from the flame. However, further research is needed to assess the existence of relationships among their outputs and operating conditions as well as to define suitable methods for signal processing. Those aspects have been addressed by means of a thorough experimental programme in a model industrial burner. Parametric analysis of flame signals recorded for a broad range of operating conditions revealed that they varied widely with the actual combustion state. In order to perform a systematic study, different correlation techniques were tried. Multiple regression methods provided some insight into mutual influences among different variables, although only in case of linear dependences. Artificial neural networks have been used as a more versatile type of algorithms, suitable for complex functional forms between input and output variables. Remarkably good results were obtained when NOx emissions or some burner settings were estimated from selected features of the flame signals, supporting their applicability for the development of advanced diagnostic methods in combustion processes. 40 refs., 13 figs., 3 tabs.

  4. Les trous noirs

    CERN Document Server

    Ioli, Elena

    2016-01-01

    L'univers est peuplé par des étoiles, des planètes, des galaxies, des astéroïdes, des comètes, mais les trous noirs en sont certainement les habitants les plus mystérieux et les plus fascinants ! Grâce à cette merveilleuse histoire racontée par papy Gino, professeur d'astronomie, les trous noirs n auront plus de secrets pour vous ! C est l'été, le soleil illumine le ciel, la plage est en feu : une journée à la plage pleine de jeux et de plongée qui va se transformer pour Bernardo, Gregorio et leurs deux amis en une aventure inattendue. Ils découvriront les secrets des trous noirs, d étranges objets célestes que personne n'a jamais vus mais qui existent bel et bien ! Grand-père Gino, un professeur d astronomie à la retraite, emmènera les enfants à l'intérieur d'un trou noir, leur expliquera pourquoi ils sont noirs, comment ils sont nés et comment les scientifiques pensent qu'ils vont mourir. Et Gino leur racontera même ce qui se trouve de l'autre côté d'un trou noir...

  5. A catalytic burner using propane and toluene alternately for the drying of textile coatings

    Energy Technology Data Exchange (ETDEWEB)

    Yongseog Seo; Sungkyu Kang [Korea Inst. of Energy Research, Taejon (Korea); Hyundong Shin [Korea Advanced Inst. of Science and Technology (KAIST), Taejon (Korea)

    1999-07-01

    This study aims to develop a low-temperature catalytic burner using propane and toluene alternately as a fuel and to apply it to the drying of acrylic coatings on textiles. Pt catalysts deposited on ceramic fibres (Al{sub 2}O{sub 3}) were employed. For propane, the diffusive catalytic burner was used. The combustion efficiency of the diffusive catalytic burner deteriorated rapidly when it was installed in downward position. Two concepts of forced diffusion combustion and premixed combustion were introduced to improve the downward placed diffusive catalytic burner. The combustion efficiency was enhanced with these modifications, but the forced diffusion was preferred since premixed combustion raised the temperature of the catalyst above 700degC leading to sintering of the catalysts. For the toluene catalytic burner the premixed combustion mode was adopted. Its optimum operation conditions were obtained by analysing the temperature within the catalyst layer and by adjustment of the toluene mixture. Field tests were performed on the drying acrylic coatings using the catalytic burners. The results showed that the use of catalytic burners had several benefits such as energy savings and less pollutant emissions. (Author)

  6. Correction, Calculation and Experimental Adjustment of Burner, Destined for Burning Methane in Electric Field

    OpenAIRE

    Pavel KLAUS; Tomčík, Petr; Kulhánek, Jiří

    2011-01-01

    In this paper was solved modification of combustion burner for experimental exam of methane combustion in the electric field with high intensity voltage. The burner was originally designed for the combustion stack gas. The burner must have been necessary adjusted, because the mixture of stack gas and air was replaced by mixture of methane and oxygen. The fundamental requirement is to adjust the height of the flame that may reach a maximum of height 100 mm. This height was re-quired because th...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1979-02-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1979-02-01

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

  9. Numerical modeling of Jinlong CJD burner copper flash smelting furnace

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Fluid flow, heat transfer and combustion in Jinlong CJD concentrate burner flash smelting furnace have been investigated by numerical modeling and flow visualization. The modeling is based on the Eulerian approach for the gas flow equations and the Lagrangian approach for the particles. Interaction between the gas phase and particle phase, such as frictional forces, heat and mass transfer, are included by the addition of sources and sinks. The modeling results including the fluid flow field, temperature field, concentration field of gas phase and the trajectories of particles have been obtained. The predicted results are in good agreement with the data obtained from a series of experiments and tests in the Jinlong Copper Smelter and the temperature error is less than 20 K.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-10-01

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

  11. Influence of the mass flow rate of secondary air on the gas/particle flow characteristics in the near-burner region of a double swirl flow burner

    Energy Technology Data Exchange (ETDEWEB)

    Jing, J.P.; Li, Z.Q.; Wang, L.; Chen, Z.C.; Chen, L.Z.; Zhang, F.C. [Harbin Institute of Technology, Harbin (China)

    2011-06-15

    The influence of the mass flow rate of secondary air on the gas/particle flow characteristics of a double swirl flow burner, in the near-burner region, was measured by a three-component particle-dynamics anemometer, in conjunction with a gas/particle two-phase test facility. Velocities, particle volume flux profiles, and normalized particle number concentrations were obtained. The relationship between the gas/particle flows and the combustion characteristics of the burners was discussed. For different mass flow rates of secondary air, annular recirculation zones formed only in the region of r/d=0.3-0.6 at x/d=0.1-0.3. With an increasing mass flow rate of secondary air, the peaks of the root mean square (RMS) axial fluctuating velocities, radial mean velocities, RMS radial fluctuating velocities, and tangential velocities all increased, while the recirculation increased slightly. There was a low particle volume flux in the central zone of the burner. At x/d=0.1-0.7, the profiles of particle volume flux had two peaks in the secondary air flow zone near the wall. With an increasing mass flow rate of secondary air, the peak of particle volume flux in the secondary air flow zone decreased, but the peak of particle volume flux near the wall increased. In section x/d=0.1-0.5, the particle diameter in the central zone of the burner was always less than the particle diameter at other locations.

  12. PECULIARITIES OF CHOICE OF BURNER DEVICES FOR HEATING FURNACES OF MACHINE-BUILDING AND METALLURGICAL PRODUCTIONS

    Directory of Open Access Journals (Sweden)

    S. V. Korneev

    2010-01-01

    Full Text Available It is shown that the choice of recuperative burners is more reasonable for different types of heating furnaces of machine-building and metallurgical productions of little efficiency.

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

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    Work on process design and LNS Burner design was deferred during this period, pending a reassessment of the project by TransAlta prior to commencement of Budget Period II, and only limited Balance of Plant engineering work was done.

  14. Optimum feeding rate of solid hazardous waste in a cement kiln burner

    National Research Council Canada - National Science Library

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

    2013-01-01

    Solid hazardous waste mixed with wood chips (SHW) is a partly CO2 neutral fuel, and hence is a good candidate for substituting fossil fuels like pulverized coal in rotary kiln burners used in cement kiln systems...

  15. Cold Gas-particle Flows in a New Swirl Pulverized-coal Burner by PDPA Measurement

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new type of swirl burner has been developed to stabilize pulverized-coal combustion by burning different types of coal at different loads and to reduce NOx formation during combustion. The burner uses a device to concentrate the coal powder in the primary-air tube that divides the primary coal-air into two streams with different pulverized-coal concentrations. This paper reports the measurement of gas-particle flows at the exit of the different swirl burners using a 3-D Phase Doppler Particle Anemometer (PDPA). The effect of different geometrical configurations on the two-phase flow field is studied. The results that give the two-phase flow fields and particle concentrations show the superiority of the new swirl burner.

  16. Demonstration test of burner liner strain measurements using resistance strain gages

    Science.gov (United States)

    Grant, H. P.; Anderson, W. L.

    1984-01-01

    A demonstration test of burner liner strain measurements using resistance strain gages as well as a feasibility test of an optical speckle technique for strain measurement are presented. The strain gage results are reported. Ten Kanthal A-1 wire strain gages were used for low cycle fatigue strain measurements to 950 K and .002 apparent strain on a JT12D burner can in a high pressure (10 atmospheres) burner test. The procedure for use of the strain gages involved extensive precalibration and postcalibration to correct for cooling rate dependence, drift, and temperature effects. Results were repeatable within + or - .0002 to .0006 strain, with best results during fast decels from 950 K. The results agreed with analytical prediction based on an axisymmetric burner model, and results indicated a non-uniform circumferential distribution of axial strain, suggesting temperature streaking.

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

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

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

    DEFF Research Database (Denmark)

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

    2004-01-01

    Co-firing biomass with coal or gas in the existing units has gained increasing interest in the recent past to increase the production of environmentally friendly, renewable green power. This paper presents design considerations for co-firing biomass with natural gas in wall-fired burners by use...... and reaction of a particle. To better understand biomass combustion and thus improve the design for co-firing biomass in wall-fired burners, non-sphericity of biomass particles is considered. To ease comparison, two cases are numerically studied in a 10m long gas/biomass co-fired burner model. (1) The biomass...... the design for co-firing biomass in wall-fired burners are finally suggested....

  19. Experimental study and numerical simulation of gas-particle flows with radial bias combustion and centrally fuel rich swirl burners

    Institute of Scientific and Technical Information of China (English)

    LI Zheng-qi; ZHOU Jue; CHEN Zhi-chao; SUN Rui; QIN Yu-kun

    2008-01-01

    Numerical simulation is applied to gas-particle flows of the primary and the secondary air ducts and burner region, and of two kinds of swirl burners. The modeling results of Radial Bias Combustion (RBC) burn-er well agreed with the data from the three-dimensional Phase-Doppler anemometry (PDA) experiment by Li, et al. The modeling test conducted in a 1025 t/h boiler was to study the quality of aerodynamics for a Central Fuel Rich (CFR) burner, and the Internal Recirculation Zone (IRZ) was measured. In addition, gas-particle flows with a CFR burner were investigated by numerical simulation, whose results accorded with the test data funda-mentally. By analyzing the distribution of gas velocity and trajectories of particles respectively, it is found that the primary air's rigidity of CFR burner is stronger than that of RBC burner, and the primary air mixes with the secondary air later. Furthermore, high concentration region of pulverized coal exists in the burner's central zone whose atmosphere is reduced, and trajectories of particles in IRZ of CFR burner are longer than that of RBC burner. They are favorable to coal's ignition and the reduction of NOx emission.

  20. Design aspects of a Low-NOx burner for a Stirling engine

    Energy Technology Data Exchange (ETDEWEB)

    Zepter, Klaus

    2003-07-01

    The Stirling engine is a promising prime mover for micro-scale combined heat and power. For Stirling engines with heat supply by combustion, the external heating system is one of the most important parts. It has major influence on the overall performance. The central component of the external heating system is the burner. This thesis describes the theoretical and experimental studies in the development of a gas fired burner for the extemal heating system that have been carried out. The focus was on low emissions and high system efficiency. As a first step, a system analysis of the external heating system is presented based on fundamental considerations about the thermodynamics and practical aspects of the Stirling engine. The results of the analysis show that the expected NOx emissions are strongly determined by the system design. Without making any restrictions to the burner design, a span of the NOx emissions with a ratio of 1:800 was found. Modern design methodology is then introduced in order to analyze a large number of different low-NOx burner concepts that were found in literature. The concepts are evaluated and classified with help of the methodology in order to find possible new low-NOx concepts by favourable combinations of generic principles. Based on this, the concept of the porous inert media (PIM) burner is chosen for further development as a burner for the Stirling engine. The selection is confirmed by an experimental benchmark study in which the PIM burner shows low NOx emissions and the lowest pressure drop compared to three other low NOx burner concepts. The optimization of the design of the PIM burner is described. A favourable combination of materials was found, which enables stable operation with a turn-down ratio of 1:15 and a span of the excess-air ratio from 1.28 to 2.0 when methane is used as the fuel. Temperature and CO measurements inside the combustion region were made which enable conclusion about the stabilization of the combustion

  1. Non-aerated burner reduces drying costs; Diffusiebrander maakt drogen goedkoper

    Energy Technology Data Exchange (ETDEWEB)

    Koopman, F.P. [Gasunie Research, Groningen (Netherlands)

    1998-10-01

    Gas-fired tumble dryers are more expensive than electric dryers. However, consumers appear to be more satisfied about the drying results of gas-fired tumble dryers. Since premix burner lead to higher natural gas conversion costs, Gasunie Research developed a non-aerated burner, featuring a simple design and a limited number of parts. Moreover, it can be manufactured at low cost, which should improve the competitiveness of the gas-fired tumble dryer

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

    Directory of Open Access Journals (Sweden)

    Oraz J.A.

    2017-01-01

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

  3. Rotrix `vortex breakdown` burner turbulence-stabilized combustion of heating oil

    Energy Technology Data Exchange (ETDEWEB)

    Hofbauer, P. [Viessmann Manufacturing Co., Inc., Ontario (Canada)

    1995-04-01

    For the past two years, the Viessmann MatriX radiant burner has been setting the standard for low emission combustion of gas. Now, with the RotriX burner, Viessmann has succeeded in drastically reducing nitrogenoxide emissions in the combustoin of oil. After a successful test period, the RotriX burner is now being introduced to the market. The RotriX oil burner consequently takes into account the mechanisms in the creation of harmful emissions in the combustion of heating oil No. 2, and guarantees stable combustion under any operating conditions. The burner has the following features: heating oil is combusted only after complete vaporization and mixing with combustion air and recirculated flue gases; the flame is not stabilized with a turbulator disk, but a strong turbulating current is created by means of the Vortex Breakdown phenomenon, which develops a very stable flame under any operating conditions; and high internal flue gas recirculation rates lower the flame temperature to the point where thermal NO formation is reduced to the same low level as in the combustion of gas. The new burner has extremely low emissions of NOx < 60 mg/kWh, and CO < 5 mg/kWh at a CO{sub 2} concentraiton of 14%.

  4. Burner Rig with an Unattached Duct for Evaluating the Erosion Resistance of Thermal Barrier Coatings

    Science.gov (United States)

    Miller, Robert A.; Kuczmarski, Maria A.; Zhu, Dongming

    2011-01-01

    Extensive computational fluid dynamics (CFD) modeling backed by experimental observation has demonstrated the feasibility of using an unattached duct to increase the velocity and spatial spread of erodent particles exiting from a burner rig. It was shown that gas velocity and temperature are mostly retained if the inner diameter of the unattached duct equaled the exit diameter of the burner rig nozzle. For particles having a mean diameter of 550 millimeters, the modeled velocity attained at a distance 2.0 in. (50.8 millimeters) beyond the exit of a 12 in. (305 millimeters) long duct was approximately twice as large as the velocity the same distance from the nozzle when the duct was not present. For finer particles, the relative enhancement was somewhat less approximately 1.5 times greater. CFD modeling was also used to guide the construction of a device for slowing down the velocity of the particles being injected into the burner rig. This device used a simple 45 degree fitting to slow the particle velocity in the feed line from 20 meters per second, which is in the range needed to convey the particles, to about 3 meters per second just as they are injected into the burner. This lower injection velocity would lessen the severity of the collision of large particles with the wall of the burner liner opposite the injection port, thereby reducing potential damage to the burner liner by high-velocity particles.

  5. Comparison of numerical methods and combustion models for LES of a ramjet

    Science.gov (United States)

    Roux, A.; Reichstadt, S.; Bertier, N.; Gicquel, L.; Vuillot, F.; Poinsot, T.

    2009-06-01

    Ramjets are very sensitive to instabilities and their numerical predictions can only be addressed adequately by Large Eddy Simulation (LES). With this technique, solvers can be implicit or explicit and handle structured, unstructured or hybrid meshes, etc. Turbulence and combustion models are other sources of differences. The impact of these options is here investigated for the ONERA ramjet burner. To do so, two LES codes developed by ONERA and CERFACS compute one stable operating condition. Preliminary LES results of the two codes underline the overall robustness of LES. Mean flow features at the various critical sections are reasonably well predicted by both codes. Disagreement mainly appear in the chamber where combustion positions differ pointing to the importance of the combustion and subgrid mixing models. The two LES produce different energy containing motions. With CEDRE, a low frequency dominates while AVBP produces different ranges of low frequencies that can be linked with acoustic modes of the configuration. To cite this article: A. Roux et al., C. R. Mecanique 337 (2009).

  6. Artaud et les Tarahumaras

    Directory of Open Access Journals (Sweden)

    Marta Mariasole Raimondi

    2008-01-01

    Full Text Available Ce film propose des scènes de vie des Tarahumaras, une ethnie originaire du Mexique installée dans le territoire de l'Etat de Chiuahua, dans un milieu montagneux très sauvage. La caméra reprend les danses et les rites de ces mangeurs de peyotl d'un regard rapide et saccadé primant des cadrages de détail où prédominent les pieds, pour nous montrer ces corps d'homme et de femme en mouvement, courant, dansant, bondissant au milieu des leurs éléments naturels : rocailles, rivières, rochers, sans...

  7. Les quartiers de Zabid

    Directory of Open Access Journals (Sweden)

    Paul Bonnenfant

    1999-08-01

    Full Text Available Je voudrais présenter ici des notes concernant les quartiers de Zabîd, ville située dans la plaine côtière de la Tihâma, à une centaine de kilomètres au sud-est d'al-Hudayda. Elles ont été rassemblées au cours d'une étude portant sur l'architecture domestique de Zabîd, dont les résultats seront publiés dans un livre ultérieur. J'ai étudié la genèse d'habitations exceptionnelles qui, avec les monuments religieux et militaires, ont valu à Zabîd d'être classée sur la liste du Patrimoine mondial ...

  8. LES INFECTIONS NOSOCOMIALES NEONATALEj

    OpenAIRE

    BELHOCINE, Meryem; BELGAID, Hanane

    2013-01-01

    introduction: Les infections nosocomiales représentent un réel problème dans les unités de néonatologie. Elles ont vu leur incidence croitre en raison de l'extension des procédures invasives de diagnostics et thérapeutiques. Objectif: déterminer l'épidémiologie des infections nosocomiales dans le sente de néonatologie a i'EHS Mère-Enfant de Tlemcen. Matériel et méthodes: Il s'agissait d'une étude rétrospective de type cas —témoin incluant tous les nouveau-nés admis en 2011 e...

  9. LES INFECTIONS NOSOCOMIALES NEONATALEj

    OpenAIRE

    BELHOCINE, Meryem; BELGAID, Hanane

    2013-01-01

    introduction: Les infections nosocomiales représentent un réel problème dans les unités de néonatologie. Elles ont vu leur incidence croitre en raison de l'extension des procédures invasives de diagnostics et thérapeutiques. Objectif: déterminer l'épidémiologie des infections nosocomiales dans le sente de néonatologie a i'EHS Mère-Enfant de Tlemcen. Matériel et méthodes: Il s'agissait d'une étude rétrospective de type cas —témoin incluant tous les nouveau-nés admis en 2011 e...

  10. Reboiser sous les tropiques

    Directory of Open Access Journals (Sweden)

    Pierlot, R.

    2007-01-01

    Full Text Available To Reafforest in the Tropics. Le sanctuaire de gorilles de Lossi constitue une expérience sur la synergie entre la recherche scientifique et la conservation de la nature. Trois parties prenantes sont impliquées dans un processus de gestion participative: l'Etat congolais, la communauté autochtone représentée par l'association des ayants droits des terres de Lossi et le programme européen sur les écosystèmes forestiers d'Afrique centrale. Une enquête de terrain a été effectuée sur le site de Lossi en 2003; elle avait comme objectif d'étudier les effets générés par la gestion participative et d'identifier les contraintes liées à l'exécution de cette approche participative en milieu réel. Les travaux de recherche sur la primatologie ont abouti à l'habituation des gorilles à la présence humaine, ce qui a conduit à la création d'un tourisme de vision de gorilles de plaine de l'Ouest. Un camp de touristes a été construit, ainsi que l'ouverture de la route d'accès au sanctuaire. Le tourisme a généré des emplois en faveur de la population locale qui est aussi prestataire de contrats sur les travaux de réfection des routes. Une partie des revenus a permis la construction d'un centre de santé intégré. Cependant, les travaux de recherche scientifique et le tourisme ont été ralentis pendant l'apparition de la fièvre hémorragique d'Ebola et pendant les trois épisodes de la guerre civile. La consolidation et le long terme de cette entreprise de cogestion du patrimoine naturel de Lossi consiste en l'établissement d'un plan d'aménagement et de gestion, qui concilie la conservation, le développement rural et la recherche scientifique tout en garantissant une répartition équitable des revenus entre les trois partenaires.

  11. Premixed Combustion of Coconut Oil on Perforated Burner

    Directory of Open Access Journals (Sweden)

    I.K.G. Wirawan

    2013-10-01

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

  12. Development of a lean premixed burner for hydrogen utilization

    Energy Technology Data Exchange (ETDEWEB)

    Keller, J.O. [Sandia National Lab., Livermore, CA (United States)

    1996-10-01

    The long-term mandate of the hydrogen program is to develop the technologies needed to establish a hydrogen economy. Although a hydrogen fueled automobile has been established as a demonstration project, there are at least three other end use sectors that are recognized by the H{sub 2} program and that are addressed by this project. These end uses are: (1) power generation from stationary turbines, (2) generation of process heat or steam, and (3) commercial and residential direct use applications. Eliminating carbon from the fuel will remove carbon containing species from the emissions, however, NO{sub x} resulting from thermal NO production cannot be ignored. Thermal NO production is minimized by reducing the peak combustion temperature and the residence time at the peak temperature. NO can be reduced to extremely low levels (a few ppm) by operating sufficiently lean to reduce the peak combustion temperatures below 1700 to 1800 K. The objectives for this project are to: (1) develop an environmentally benign and safe burner operating on hydrogen in a lean premixed mode, (2) provide a facility in which fundamental investigations can be performed to support other programs.

  13. Fat burners: nutrition supplements that increase fat metabolism.

    Science.gov (United States)

    Jeukendrup, A E; Randell, R

    2011-10-01

    The term 'fat burner' is used to describe nutrition supplements that are claimed to acutely increase fat metabolism or energy expenditure, impair fat absorption, increase weight loss, increase fat oxidation during exercise, or somehow cause long-term adaptations that promote fat metabolism. Often, these supplements contain a number of ingredients, each with its own proposed mechanism of action and it is often claimed that the combination of these substances will have additive effects. The list of supplements that are claimed to increase or improve fat metabolism is long; the most popular supplements include caffeine, carnitine, green tea, conjugated linoleic acid, forskolin, chromium, kelp and fucoxanthin. In this review the evidence for some of these supplements is briefly summarized. Based on the available literature, caffeine and green tea have data to back up its fat metabolism-enhancing properties. For many other supplements, although some show some promise, evidence is lacking. The list of supplements is industry-driven and is likely to grow at a rate that is not matched by a similar increase in scientific underpinning.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-01-01

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

  15. New recuperator- and regenerator burners reduce waste-gas losses and emissions; Verringerung der Abgasverluste und Emissionen durch neue Rekuperator und Regeneratorbrenner

    Energy Technology Data Exchange (ETDEWEB)

    Wuenning, Joachim G. [WS Waermeprozesstechnik GmbH, Renningen (Germany)

    2009-10-15

    The reduction of waste gas losses is often the most effective and economic way to increase the efficiency of industrial furnaces. This article will present two new burner models, enabling to cut waste gas losses of finned recuperative burners almost in half. The regenerative burner achieves highest efficiency but one has to accept a certain expenditure for cyclic switching and exhaust gas suction. This might not be justified for smaller burner sizes and furnaces. The new gap flow recuperative burner reaches almost the same efficiencies with a recuperative system. Both burner models use flameless oxidation technology for lowest NO{sub x} emissions. (orig.)

  16. Flame investigations of coal and biomass combustion with a 35 MW DS {sup registered} burner and modification for indirect firing

    Energy Technology Data Exchange (ETDEWEB)

    Weirich, Tanja; Leisse, Alfons; Niesbach, Juergen; Kuhr, Christian; Koczorowski, Hans-Joachim [Hitachi Power Europe GmbH, Duisburg (Germany)

    2010-07-01

    Based on experimental flame investigations the capability of a DS {sup registered} burner to operate in a wide load range with different fuels was verified. A DS {sup registered} burner with a thermal capacity of 35 MW was installed in a combustion test facility in order to perform in-flame ash sampling and detailed measurements of temperatures, flue gas species as well as convective and radioactive heat fluxes. Moreover the DS {sup registered} burner was modified to DS {sup registered} T burner for the use of dense phase fuel conveying for indirect firing systems including the oxyfuel process. (orig.)

  17. Les Cahiers du CREAD

    African Journals Online (AJOL)

    Admin

    C'est dans un climat de crise économique où les pouvoirs publics perdent la capacité de ... d'offres d'emploi et permettre aux usagers d'accéder aux ressources offertes par la ville, ...... «Croissance urbaine, mobilité et transport urbain.

  18. Notes sur les Limaces

    NARCIS (Netherlands)

    Regteren, van C.O.

    1964-01-01

    9. DESCRIPTION D'UNE NOUVELLE ESPÈ CE DE DEROCERAS DES ENVIRONS DE GRENADE 1) Même pour celui qui ne dispose pas d'une voiture, la ville de Grenade est un magnifique centre d'excursions. Les trams et autobus permettent au naturaliste de sortir de la ville en toutes directions et de commencer ses pro

  19. Les formes du fond

    Directory of Open Access Journals (Sweden)

    Michel Maffesoli

    2004-12-01

    Full Text Available Il n'est pas vrai que la nature a horreur du vide. Peut-être même s'y complait-elle. Le creux est aussi une modalité de l'être. Il est possible de s'y nicher, de s'y lover paresseusement et, ainsi, de se protéger contre l'angoisse du temps qui passe. Le creux des apparences est, à certains moments, une des formes d'expression de la vie sociale. Encore faut-il savoir le reconnaître. Certes, nous avons tous une existence personnelle, mais nous sommes, également, les représentants, parfois même les victimes, d'un "esprit commun", peut-être même d'un "inconscient collectif" qui s'est constitué de siècle en siècle. Et, très souvent, là où nous croyons exprimer nos propres idées, nous ne sommes que les porte-voix, les figurants d'un vaste "theatrum mundi" aux dimensions infinies.

  20. Notes sur les Limaces

    NARCIS (Netherlands)

    Regteren, van C.O.

    1964-01-01

    9. DESCRIPTION D'UNE NOUVELLE ESPÈ CE DE DEROCERAS DES ENVIRONS DE GRENADE 1) Même pour celui qui ne dispose pas d'une voiture, la ville de Grenade est un magnifique centre d'excursions. Les trams et autobus permettent au naturaliste de sortir de la ville en toutes directions et de commencer ses

  1. Simulation Modeling of an Enhanced Low-Emission Swirl-Cascade Burner

    Energy Technology Data Exchange (ETDEWEB)

    Ala Qubbaj

    2004-09-01

    ''Cascade-burners'' is a passive technique to control the stoichiometry of the flame through changing the flow dynamics and rates of mixing in the combustion zone with a set of venturis surrounding the flame. Cascade-burners have shown advantages over other techniques; its reliability, flexibility, safety, and cost makes it more attractive and desirable. On the other hand, the application of ''Swirl-burners'' has shown superiority in producing a stable flame under a variety of operating conditions and fuel types. The basic idea is to impart swirl to the air or fuel stream, or both. This not only helps to stabilize the flame but also enhances mixing in the combustion zone. As a result, nonpremixed (diffusion) swirl burners have been increasingly used in industrial combustion systems such as gas turbines, boilers, and furnaces, due to their advantages of safety and stability. Despite the advantages of cascade and swirl burners, both are passive control techniques, which resulted in a moderate pollutant emissions reduction compared to SCR, SNCR and FGR (active) methods. The present investigation will study the prospects of combining both techniques in what to be named as ''an enhanced swirl-cascade burner''. Natural gas jet diffusion flames in baseline, cascade, swirl, and swirl-cascade burners were numerically modeled using CFDRC package. The thermal, composition, and flow (velocity) fields were simulated. The numerical results showed that swirl and cascade burners have a more efficient fuel/air mixing, a shorter flame, and a lower NOx emission levels, compared to the baseline case. The results also revealed that the optimal configurations of the cascaded and swirling flames have not produced an improved performance when combined together in a ''swirl-cascade burner''. The non-linearity and complexity of the system accounts for such a result, and therefore, all possible combinations, i

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

    Science.gov (United States)

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

    2009-12-15

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

  3. Les barrages alpins

    Directory of Open Access Journals (Sweden)

    Alain Marnezy

    2009-03-01

    Full Text Available Les barrages-réservoirs de montagne ont été réalisés initialement dans les Alpes pour répondre à la demande d’énergie en période hivernale. Une certaine diversification des usages de l’eau s’est ensuite progressivement développée, en relation avec le développement touristique des collectivités locales. Aujourd’hui, la participation des ouvrages d’Électricité De France à la production de neige de culture représente une nouvelle étape. Dans les régions où les aménagements hydroélectriques sont nombreux, les besoins en eau pour la production de neige peuvent être résolus par prélèvements à partir des adductions EDF. Les gestionnaires de stations échappent ainsi aux inconvénients liés à la construction et à la gestion des « retenues collinaires ». Cette évolution, qui concerne déjà quelques régions alpines comme la haute Maurienne ou le Beaufortin, apparaît comme une forme renouvelée d’intégration territoriale de la ressource en eau.Mountain reservoirs were initially built in the Alps to meet energy needs in the winter. A certain diversification in the uses of water then gradually developed, related to tourism development in the local communities. Today, the use of facilities belonging to EDF (French Electricity Authority to provide water for winter resorts to make artificial snow represents a new phase. By taking water from EDF resources to supply snow-making equipment, resort managers are thus able to avoid the problems related to the construction and management of small headwater dams. This new orientation in the use of mountain water resources already affects a number of alpine regions such as the Upper Maurienne valley and Beaufortain massif and represents a renewed form of the territorial integration of water resources.

  4. LES APPROCHES PSYCHOSOCIOLOGIQUES DES ORGANISATIONS

    Directory of Open Access Journals (Sweden)

    Deaconu Alecxandrina

    2008-05-01

    Full Text Available Les préoccupations pour bien comprendre la complexité des organisations sont bien connues dans la théorie et la pratique du management. La motivation la plus fréquente pour toutes les recherches et les investigationes faites a été fondée sur le besoin de savoir gérer les situations diverses en vue de maximiser la performance organisationnelle. En ce qui nous concerne, pour enrichir les informations disponibles, nous voulons élargir, dans notre communication, les approches traditionelles, focaliser l’attention sur la dimension psychologiques des organisations et présenter les mécanismes qui favorisent l’implication des salariés.

  5. Cyrano et les hydropotes

    Directory of Open Access Journals (Sweden)

    Alain Mothu

    2007-10-01

    Full Text Available « Car il sera grand devant le Seigneur. Il ne boira ni vin, ni liqueur enivrante, et il sera rempli de l’Esprit-Saint dès le sein de sa mère »(Luc, I, 15Cyrano dédie sa lettre à la gloire de l’aqueduc d’Arcueil et des fontaines parisiennes qu’il alimentait, à « (ses amis les buveurs d’eau ». Cette dédicace abrite peut-être une fine allusion au fait que la construction de l’« acqueduc Médicis », entamée en 1612, fut financée en partie par un droit d’entrée à Paris imposé sur les vins, comme ...

  6. Faire voter les morts

    Directory of Open Access Journals (Sweden)

    Boris Jeanne

    2008-04-01

    Full Text Available Le film de zombie a toujours été politique. Marxiste même, associant dans une lecture rapide du Capital les morts-vivants et le Lumpenproletariat, et s’en prenant vivement à la société de consommation, que ce soit chez les fondateurs (George Romero ou leurs épigones (L’armée des morts de Zack Snyder se passe dans un centre commercial. En contexte post-11 septembre, ce sont Bush et Fox News qui en deviennent la cible, et le film de zombie réalisé par Joe Dante pour la première saison de la ...

  7. Development and certification of the innovative pioneer oil burner for residential heating appliances

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, B. [Heat Wise Inc., Ridge, NY (United States)

    1997-09-01

    The Pioneer burner represents another important milestone for the oil heat industry. It is the first practical burner design that is designated for use in small capacity heating appliances matching the needs of modern energy efficient home designs. Firing in the range of 0.3 GPH to 0.65 GPH (40,000-90,000 Btu/hr) it allows for new oil heating appliance designs to compete with the other major fuel choices in the small design load residential market. This market includes energy efficient single family houses, town-houses, condominiums, modular units, and mobile homes. The firing range also is wide enough to cover a large percentage of more conventional heating equipment and home designs as well. Having recently passed Underwriters Laboratory certification tests the burner in now being field tested in several homes and samples are being made available to interested boiler and furnace manufacturers for product development and application testing.

  8. Investigation of lean combustion stability and pressure drop in porous media burners

    Science.gov (United States)

    Sobhani, Sadaf; Haley, Bret; Bartz, David; Dunnmon, Jared; Sullivan, John; Ihme, Matthias

    2016-11-01

    The stability and thermal durability of combustion in porous media burners (PMBs) is examined experimentally and computationally. For this, two burner concepts are considered, which consist of different pore topologies, porous materials, and matrix arrangements. Long-term material durability tests at constant and cycled on-off conditions are performed, along with a characterization of combustion stability, pressure drop and pollutant emissions for a range of equivalence ratios and mass flow rates. Experimental thermocouple temperature measurements and pressure drop data are presented and compared to results obtained from one-dimensional volume-averaged simulations. Experimental and model results show reasonable agreement for temperature profiles and pressure drop evaluated using Ergun's equations. Enhanced flame stability is illustrated for burners with Yttria-stabilized Zirconia Alumina upstream and Silicon Carbide in the downstream combustion zone. Results reinforce concepts in PMB design and optimization, and demonstrate the potential of PMBs to overcome technological barriers associated with conventional free-flame combustion technologies.

  9. PREDICTION OF COMBUSTION CHARACTERISTICS OF A TYPICAL BIOGAS BURNER USING CFD

    Directory of Open Access Journals (Sweden)

    K. MADHUSOODAN PILLAI

    2012-07-01

    Full Text Available Biogas is obtained from anaerobic digestion of biodegradable materials such as agricultural waste, animal waste, and othertype of household solid waste and its main constituents are CH4 and CO2. Effects of the concentration of each species are very important in the biogas combustion. The present study focuses on the effect of inlet velocities of methane and air on the flame temperature in a biogas burner lamp. The model of biogas burner lamp is constructed by using the CFD software GAMBIT and the simulation process was performed by using Fluent Software. The flame temperature obtained is 2172 k when the inlet velocities of methane and air are 0.2m/s and 0.8 m/s respectively. Results of this study will provide valuable data for biogas burner lamp manufacturers.

  10. Development of lean premixed low-swirl burner for low NO{sub x} practical application

    Energy Technology Data Exchange (ETDEWEB)

    Yegian, D.T.; Cheng, R.K.

    1999-07-07

    Laboratory experiments have been performed to evaluate the performance of a premixed low-swirl burner (LSB) in configurations that simulate commercial heating appliances. Laser diagnostics were used to investigate changes in flame stabilization mechanism, flowfield, and flame stability when the LSB flame was confined within quartz cylinders of various diameters and end constrictions. The LSB adapted well to enclosures without generating flame oscillations and the stabilization mechanism remained unchanged. The feasibility of using the LSB as a low NO{sub x} commercial burner has also been verified in a laboratory test station that simulates the operation of a water heater. It was determined that the LSB can generate NO{sub x} emissions < 10 ppm (at 3% O{sub 2}) without significant effect on the thermal efficiency of the conventional system. The study has demonstrated that the lean premixed LSB has commercial potential for use as a simple economical and versatile burner for many low emission gas appliances.

  11. SIMULATION MODELING OF AN ENHANCED LOW-EMISSION SWIRL-CASCADE BURNER

    Energy Technology Data Exchange (ETDEWEB)

    Ala Qubbaj

    2004-04-01

    Based on the physical and computational models outlined in the previous technical progress reports, Natural gas jet diffusion flames in baseline, cascade, swirl, and swirlcascade burners were numerically modeled. The thermal, composition, and flow (velocity) fields were simulated. The temperature, CO{sub 2} and O{sub 2} concentrations, as well as the axial and radial velocity profiles were computed and analyzed. The numerical results showed that swirl and cascade burners have a more efficient fuel/air mixing, a shorter flame, and a lower NOx emission levels, compared to the baseline case. The results also revealed that the optimal configurations of the cascaded and swirling flames have not produced an improved performance when combined together in a ''swirl-cascade burner''.

  12. Les Tinamous. Tinami

    NARCIS (Netherlands)

    Schlegel, H.

    1880-01-01

    Les Tinamous forment une tribu d’oiseaux parfaitement isolée et circonscrite, et bornée à la partie de l’Amérique comprise entre le Mexico méridional et la Patagonie. Ils se rattachent, toutefois, naturellement à l’ordre des Gallinae, tout en offrant certaines affinités avec l’ordre des Autruches. I

  13. Les urgences infectieuses ORL

    Science.gov (United States)

    Sereme, Moustapha; Tarnagda, Souleymane; Guiguimde, Patrice; Gyebre, Yvette Marie Chantal; Ouedraogo, Bertin; Céline, Bambara; Ouattara, Maimouna; Ouoba, Kampadilemba

    2016-01-01

    Affections gravissimes à pronostic très réservé particulièrement dans notre contexte de sous médicalisation et de pauvreté. Notre but en initiant ce travail est de déterminer les étiologies de ces urgences et discuter de leur prise en charge thérapeutique. Étude de type rétrospective et descriptive sur 05 ans, au total 52 dossiers cliniques ont été inclus. Ces infections ont représenté 0,33% de nos consultations. La moyenne d'âge de nos patients a été 23 ans. Le jeune âge, les traitements inappropriés et certaines affections ORL ont été retrouvés comme facteurs favorisants. Les motifs de consultation ont été variés en fonction du siège de l'infection, cependant deux signes cliniques ont été constants: la douleur et la fièvre. L'adénophlegmon, le phlegmon péri-amygdalien, les cellulites ont été nos principales étiologies avec le streptocoque et le staphylocoque comme principaux germes en cause. L'antibiothérapie probabiliste a été utilisée en première intention notamment l'association céphalosporine de 3ème génération + aminoside + imidazolé. L'évolution clinique de nos patients a été marquée par la survenue de complications locales et générales. Urgence diagnostic et thérapeutique leur évolution reste encore émaillée de complication en raison de la consultation tardive de nos patients. PMID:28154719

  14. Les Cahiers du CREAD

    African Journals Online (AJOL)

    Admin

    l'apprentissage implicite ou explicite qui fonctionne comme un système de schèmes générateurs, est générateur de stratégie qui peuvent être objectivement conformes ..... passe mais il a une idée de toutes les nouvelles technologies utilisées, de ..... ction dans une situation de dépendance épistémique, de problème.

  15. Some parameters and conditions defining the efficiency of burners in the destruction of long-lived nuclear wastes

    Indian Academy of Sciences (India)

    V V Seliverstov

    2007-02-01

    A number of new wordings and statements regarding the targeted problem of destruction of long-lived wastes (transmutation) is considered. Some new criteria concerning the efficiency of a particular burner type are proposed. It is shown that the destruction efficiency of a specific burner is greatly influenced by the prospective time period of the whole destruction process.

  16. Les tactiques de Chronos

    CERN Document Server

    Klein, Etienne

    2009-01-01

    Nous ne doutons pas de l'existence du temps, qui demeure pourtant un objet introuvable. Nous voyons, entendons, goûtons, touchons dans le temps, mais non le temps lui-même. Il concerne toute chose, contraint tout, mais de quelle façon ? Est-il apparu en même temps que l'univers ou l'a t-il précédé ? Est-il dans le monde ou le contient-il ? S'écoule-t-il en sens unique ? Serait-ce la mort qui nous obligerait à penser le temps ? Au XXe siècle, la physique a bouleversé notre conception du temps et en vient à effleurer des questions jusque la façon dont l'homme choisit de vivre et de se vivre. Quelles sont les convergences et les différence entre le temps physique et le temps sensible, existentiel ? Pour éclairer les paradoxes, répondre aux questions, Etienne Klein puise, en contrepoint de la physique, dans la philosophie, la psychologie, la littérature, ma poésie... et le sport.

  17. Les pirogues du Maroni

    Directory of Open Access Journals (Sweden)

    Sophie François

    2012-04-01

    Full Text Available Sur le Maroni, fleuve frontière entre la Guyane française et le Surinam, les pirogues amarrées le long des berges se comptent par centaines. Elles représentent le seul moyen de transport pour les milliers de personnes vivant sur les rives du Maroni. Les différentes formes de pirogues sont révélatrices de la diversité géographique du Maroni et de la diversité culturelle des populations. Les Amérindiens du littoral naviguent uniquement dans l’estuaire du fleuve. Ils construisent des pirogues larges, hautes et terminées à la poupe par une haute étrave qui fend les vagues. Ces pirogues sont construites à partir d’une coque monoxyle expansée et rehaussée d’un ou de deux bordages. En chauffant la grume évidée, le bois acquiert une certaine plasticité qui permet d’écarter les flancs et d’obtenir une coque très large à partir d’un arbre de faible diamètre. Les Bushinenge, populations d’origine africaine qui ont déserté les grandes plantations de la Guyane hollandaise dès le début du XVIIe siècle et se sont installées sur les deux rives du Maroni, ont développé des formes de pirogues adaptées au passage des sauts. Leurs pirogues, construites également en expansant la coque au feu, sont étroites et longues et possèdent des extrémités curvilignes qui dépassent largement au–dessus du bordage. Les longues pirogues à moteur comme les canots–pagaies sont ornés de motifs d’entrelacs appelés tembé ; et de décors d’inspiration contemporaine. L’inventaire des pirogues du Maroni a mis en évidence la richesse et la vitalité du patrimoine nautique de cette région au début du XXIe siècle, tant au niveau des formes des embarcations que des décors et des pratiques de navigation.On the Maroni river, natural border between French Guyana and the Surinam, canoes tied to the river banks can be counted by the hundreds. They are the only mean of transportation for thousands of people living along the

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

    Science.gov (United States)

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

    2017-08-01

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

  19. Scaling the weak-swirl burner from 15 kW to 1 MW

    Energy Technology Data Exchange (ETDEWEB)

    Yegian, D.T.; Cheng, R.K. [Lawrence Berkeley National Lab., CA (United States). Environmental Energy Technologies Div.; Hack, R.L.; Miyasato, M.M.; Chang, A.; Samuelsen, G.S. [Univ. of California, Irvine, CA (United States). UCI Combustion Lab.

    1998-03-01

    With the passage of SCAQMD 1146.2, low NO{sub x} regulations will be enforced for new water heaters and boilers from 22 to 585 kW starting January 1, 2000; less than two years away. This has given an added impetus to develop a burner capable of producing NO{sub x} < 30 ppm and CO < 400 ppm without substantial manufacturing costs or complexity. Developed at the Berkeley Lab, the Weak-Swirl Burner (WSB) operates in the lean premixed combustion mode over a wide firing and equivalence ratio range. This work investigated scaling issues (e.g. swirl rates and stability limits) of the WSB when fired at higher rates useful to industry. Three test configurations which varied the ratio of furnace area to burner area were utilized to understand the effects of burner chamber coupling on emissions and stability. Preliminary tests from 12 to 18 kW of a WSB in a commercial heat exchanger were undertaken at LBNL, with further testing from 18 to 105 kW completed at UCI Combustion Laboratory in an octagonal enclosure. After scaling the small (5 cm diameter) to a 10 cm WSB, the larger burner was fired from 150 to 600 kW within a 1.2 MW furnace simulator at UCICL. Test results demonstrate that NO{sub x} emissions (15 ppm at 3% O{sub 2} at equivalence ratio {phi} = 0.80) were invariant with firing rate and chamber/burner ratio. However, the data indicates that CO and UHC are dependent on system parameters, such that a minimum firing rate exists below which CO and UHC rise from lower limits of 25 ppm and 0 ppm respectively.

  20. Development of the Radiation Stabilized Distributed Flux Burner. Phase 1, final report

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, J.D.; Duret, M.J.

    1997-06-01

    The RSB was first developed for Thermally Enhanced Oil Recovery steamers which fire with a single 60 MMBtu/hr burner; the California Energy Commission and Chevron USA were involved in the burner development. The burner has also since found applications in refinery and chemical plant process heaters. All Phase I goals were successfully met: the RSB achieved sub-9 ppM NOx and sub-50 ppM CO emissions using high excess air, external flue gas recirculation (FGR), and fuel staging in the 3 MMBtu/hr laboratory watertube boiler. In a test in a 50,000 lb/hr oil field steamer with fuel staging, it consistently achieved sub-20 ppM NOx and as low as 10 ppM NOx. With high CO{sub 2} casing gas in this steamer, simulating external FGR, sub-20 ppM NOx and as low as 5 ppM NOx were achieved. Burner material cost was reduced by 25% on a per Btu basis by increasing the effective surface firing rate at the burner; further reductions will occur in Phase II. The market for 30 ppM and 9 ppM low NOx burners has been identified as package boilers in the 50,000 to 250,000 lb/hr size range (the 30 ppM is for retrofit, the 9 ppM for the new boiler market). Alzeta and Babcock & Wilcox have teamed to sell both boiler retrofits and new boilers; they have identified boiler designs which use the compact flame shape of the RSB and can increase steam capacity while maintaining the same boiler footprint. Alzeta, Chevron, and B & W have teamed to identify sites to demonstrate the RSB in Phases II and III. In Phase II, the RSB will be demonstrated in a 100,000 lb/hr industrial watertube boiler.

  1. LES SOFTWARE FOR THE DESIGN OF LOW EMISSION COMBUSTION SYSTEMS FOR VISION 21 PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    Steven Cannon; Clifford Smith

    2003-04-01

    Application and testing of the new combustion Large Eddy Simulation (LES) code for the design of advanced gaseous combustion systems is described in this 10th quarterly report. CFD Research Corporation has developed the LES module within the parallel, unstructured solver included in the commercial CFD-ACE+ software. In this quarter, validation and testing of the combustion LES code was performed for the DOE-Simval combustor. Also, Beta testing by consortium members was performed for various burner and combustor configurations. In the two quarters ahead, CFDRC will validate the code on the new DOE SimVal experiments. Experimental data from DOE should be available in June 2003, though LES calculations are currently being performed. This will ensure a truly predictive test of the software. CFDRC will also provide help to the consortium members on running their cases, and incorporate improvements to the software suggested by the beta testers. The beta testers will compare their predictions with experimental measurements and other numerical calculations. At the end of this project (October, 2003), a final released version of the software will be available for licensing to the general public.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hamid Farzan; Jennifer Sivy; Alan Sayre; John Boyle

    2003-07-01

    Under sponsorship of the Department of Energy's National Energy Technology Laboratory (NETL), McDermott Technology, Inc. (MTI), the Babcock & Wilcox Company (B&W), and Fuel Tech teamed together to investigate an integrated solution for NOx control. The system was comprised of B&W's DRB-4Z{trademark} low-NO{sub x} pulverized coal (PC) burner technology and Fuel Tech's NO{sub x}OUT{reg_sign}, a urea-based selective non-catalytic reduction (SNCR) technology. The technology's emission target is achieving 0.15 lb NO{sub x}/10{sup 6} Btu for full-scale boilers. Development of the low-NOx burner technology has been a focus in B&W's combustion program. The DRB-4Z{trademark} burner (see Figure 1.1) is B&W's newest low-NO{sub x} burner capable of achieving very low NO{sub x}. The burner is designed to reduce NO{sub x} by diverting air away from the core of the flame, which reduces local stoichiometry during coal devolatilization and, thereby, reduces initial NO{sub x} formation. Figure 1.2 shows the historical NO{sub x} emission levels from different B&W burners. Figure 1.2 shows that based on three large-scale commercial installations of the DRB-4Z{trademark} burners in combination with OFA ports, using Western subbituminous coal, the NO{sub x} emissions ranged from 0.16 to 0.18 lb/10{sup 6} Btu. It appears that with continuing research and development the Ozone Transport Rule (OTR) emission level of 0.15 lb NO{sub x}/10{sup 6} Btu is within the reach of combustion modification techniques for boilers using western U.S. subbituminous coals. Although NO{sub x} emissions from the DRB-4Z{trademark} burner are nearing OTR emission level with subbituminous coals, the utility boiler owners that use bituminous coals can still benefit from the addition of an SNCR and/or SCR system in order to comply with the stringent NO{sub x} emission levels facing them.

  3. Les alfabetitzacions digitals

    Directory of Open Access Journals (Sweden)

    José Luis Rodríguez Illera

    2005-01-01

    Full Text Available En este artículo se analiza el concepto de alfabetizaciones digitales, enfatizando los cambios en la idea de alfabetización y los efectos sobre las denominadas «nuevas alfabetizaciones». Se proponen los ejes principales para analizarlo, considerando con más detalle lo que suponen las nuevas prácticas de escritura en el caso de la multimedialidad. Finalmente, se apunta que las alfabetizaciones digitales requieren ser tomadas como un campo de investigación educativa y no únicamente como capacitación en el uso de los medios digitales. _____________________________________________________________________________________________________________________________ Cet article analyse le concept d’alphabétisation digitale, en mettant l’accent sur les changements de l’idée même d’alphabétisation ainsi que sur les effets quant aux «nouvelles alphabétisations». Il pose les axes principaux permettant d’analyser ce concept, en envisageant plus en détail ce qu’impliquent les nouvelles pratiques d’écriture dans un environnement multimédia. Enfi n, il insiste sur le fait que les alphabétisations digitales doivent être considérées comme un domaine de recherche et pas seulement comme une capacitation dans l’usage des moyens digitaux.This paper analyses the concept of digital literacies, underlining the changes in the idea of literacy and the effects on the socalled “new literacies”. The main focus points are proposed for the analysis, taking a closer look at what new writing practices suppose in the case of multimediality. Last of all, it is pointed out that digital literacies need to be treated as a fi eld of educational research and not only as an enabling factor in the use of digital media.En este artículo se analiza el concepto de alfabetizaciones digitales, enfatizando los cambios en la idea de alfabetización y los efectos sobre las denominadas «nuevas alfabetizaciones». Se proponen los ejes principales para

  4. Development and testing of the pore burner technology for oil burners. Final report; Entwicklung und Erprobung der Porenbrennertechnik fuer Oelbrenner. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Durst, F.; Trimis, D.; Wawrzinek, K.; Koehne, H.; Lucka, K.; Rudolphi, I.; Hatzfeld, O.; Volkert, J.; Rutsche, A.; Adler, J.; Standke, G.; Haase, F.; Krueger, K.; Kuechen, C.

    2001-11-01

    The application of the pore burner technology in oil burners was investigated. Together with a new concept for oil-fuelled high efficiency boilers, this technology opens up a vast potential for energy conservation and pollutant reduction. [German] Der Waermebedarf von Wohneinheiten nimmt, flankiert durch Vorgaben des Gesetzgebers, in Zukunft weiter ab. Parallel dazu werden die Grenzwerte fuer die maximal zulaessigen Schadgasemissionen der Heizanlagen verschaerft und die emissionsintensiven und im intermittierenden Betrieb bei Teillast sehr haeufigen Start/Stop-Betriebsphasen konventioneller Oel-Heizsysteme strenger bewertet. Ziel dieses Vorhabens ist es, die fuer die Verbrennung gasfoermiger Brennstoffe bereits erfolgreich demonstrierten Vorteile der Porenbrennertechnik (sehr niedrige Schadstoffemissionen, aeusserst breiter Bereich der Leistungsmodulation bis 1:20, hohe Energiedichte und damit kleine Baugroesse, minimale Geraeuschemission) auch fuer die Verbrennung von Heizoel nutzbar zu machen. In Verbindung mit einem neuen Konzept fuer die Oel-Brennwerttechnik erschliesst diese Technologie ein hohes Einsparpotential hinsichtlich Energieverbrauch und Schadstoffemissionen. (orig.)

  5. Des Orques sous les tropiques

    OpenAIRE

    Sounguet, Guy-Philippe

    2002-01-01

    Les populations de Cétacés qui vivent au Sud et qui atteignent les côtes du Gabon, quittent la région antarctique à la fin de l'été austral. Lorsque la banquise s'étend vers le nord, ils remontent vers les côtes occidentales africaines en empruntant le courant froid antarctique qui les portent jusqu'à l'équateur. Cette migration saisonnière Sud-Nord s'effectue durant l'hiver austral. Les animaux font leur apparition dans les régions équatoriales en juin pour repartir à partir de septembre. Bi...

  6. DEVELOPMENT AND DEMONSTRATION OF NOVEL LOW-NOx BURNERS IN THE STEEL INDUSTRY

    Energy Technology Data Exchange (ETDEWEB)

    Cygan, David

    2006-12-28

    Gas Technology Institute (GTI), together with Hamworthy Peabody Combustion Incorporated (formerly Peabody Engineering Corporation), the University of Utah, and Far West Electrochemical have developed and demonstrated an innovative combustion system suitable for natural gas and coke-oven gas firing within the steel industry. The combustion system is a simple, low-cost, energy-efficient burner that can reduce NOx by more than 75%. The U.S. steel industry needs to address NOx control at its steelmaking facilities. A significant part of NOx emissions comes from gas-fired boilers. In steel plants, byproduct gases – blast furnace gas (BFG) and coke-oven gas (COG) – are widely used together with natural gas to fire furnaces and boilers. In steel plants, natural gas can be fired together with BFG and COG, but, typically, the addition of natural gas raises NOx emissions, which can already be high because of residual fuel-bound nitrogen in COG. The Project Team has applied its expertise in low-NOx burners to lower NOx levels for these applications by combining advanced burner geometry and combustion staging with control strategies tailored to mixtures of natural gas and byproduct fuel gases. These methods reduce all varieties of NOx – thermal NOx produced by high flame temperatures, prompt NOx produced by complex chain reactions involving radical hydrocarbon species and NOx from fuel-bound nitrogen compounds such as ammonia found in COG. The Project Team has expanded GTI’s highly successful low-NOx forced internal recirculation (FIR) burner, previously developed for natural gas-fired boilers, into facilities that utilize BFG and COG. For natural gas firing, these burners have been shown to reduce NOx emissions from typical uncontrolled levels of 80-100 vppm to single-digit levels (9 vppm). This is done without the energy efficiency penalties incurred by alternative NOx control methods, such as external flue gas recirculation (FGR), water injection, and selective non

  7. Video a les aules

    OpenAIRE

    Ramírez León, Vanessa

    2012-01-01

    Memòria del Projecte Final de Màster "Vídeo a les aules", consistent en una plataforma col·laborativa online per potenciar l'ús didàctic del vídeo a l'aula. "Video in the classroom" is an online collaborative platform to promote the educational use of video in the classroom. Memoria del Proyecto Final de Máster "Video en las aulas", consistente en una plataforma colaborativa online para potenciar el uso didáctico del vídeo en el aula.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-08-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-06-01

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

  10. Confronting the "Bra-Burners": Teaching Radical Feminism with a Case Study

    Science.gov (United States)

    Kreydatus, Beth

    2008-01-01

    In many of the U.S. History courses the author has taught, she has encountered students who refer to the second-wave feminists of the 1960s and 1970s as "bra-burners." Unsurprisingly, these students know very little about the origin of this epithet, and frequently, they know even less about the women's movement generally. Second-wave feminism, and…

  11. Cordierite Bricks for Ceramic Burner of Hot Blast Stove YB/T 4128-2005

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaohui; Chai Junlan

    2009-01-01

    @@ 1 Scope This standard specifies the classification,brand,technical requirements,shape and dimension,test method,quality appraisal procedure,packing,marking,transportation,storage and quality certificate of cordierite bricks for ceramic burner of blast furnace and hot blast stove.

  12. Performance analysis of porous radiant burners used in LPG cooking stove

    Directory of Open Access Journals (Sweden)

    P. Muthukumar, Piyush Anand, Prateek Sachdeva

    2011-03-01

    Full Text Available This paper discusses the performance investigations of a porous radiant burner (PRB used in LPG cooking stove. Performance of the burner was studied at different equivalence ratios and power intensities. Thermal efficiency was found using the water-boiling test described in IS: 4246:2002. The newly designed PRB showed a maximum thermal efficiency of about 71%, which is 6% higher than that of the conventional burners. Influence of ambient temperature on the thermal efficiency of the PRB was also investigated. Using a PRB of 80 mm diameter at the operating conditions of 0.68 equivalence ratio and 1.24 kW power intensity, the thermal efficiency was found to increase from 61% at 18.5 oC to 71% at 31 oC ambient temperature. The CO and NOx emissions of the PRB are in the range of 9 to 16 ppm and 0 to 0.2 ppm, respectively, while the respective values for the conventional burner are in the range of 50 to 225 ppm and 2 to 7 ppm.

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    This paper discusses optimal control strategies for switching between different burner modes in a novel compact  marine boiler design. The ideal behaviour is defined in a performance index the minimisation of which defines an ideal trade-off between deviations in boiler pressure and water level...

  14. The porous medium oil burner applied to a household heating system

    Energy Technology Data Exchange (ETDEWEB)

    Heiderman, T.; Rutsche, A.; Tanke, D. [Invent GmbH, Uttenreuth (Germany); Hatzfeld, O.; Koehne, H.; Lucka, K.; Rudolphi, I. [Technische Hochschule Aachen (Germany). Lehr- und Forschungsgebiet Energie- und Stofftransport; Durst, F.; Trimis, D.; Wawrzinek, K. [Erlangen-Nuernberg Univ., Erlangen (Germany). Lehrstuhl fuer Stroemungsmechanik

    2000-03-01

    The thermal power used in the household is a combination of two contributions. Firstly, the power for the water heating and secondly, for the room heating. While the first contribution is roughly constant at around 20 kW the latter decreases for modern low energy houses continually down to a few kW in the last years. Therefore, a heating system with a high dynamic power range like the porous medium burner technology developed at the University of Erlangen-Nuernberg is required. This burner technology is extended to oil burner using the concept of cold flames in the oil evaporation zone, developed at EST Aachen. The oil burner is working with high thermal efficiency and low noise. The pollutant emission low is due to this new combustion concept and due to the strongly reduced number of start-stop-cycles. (orig.) [German] Waehrend der Raumwaermebedarf moderner Wohneinheiten stetig sinkt, erfordert die Warmwasserbereitung nach wie vor die Bereitstellung ausreichend grosser Waermeleistungen. Aus diesem Grund geht der Trend bei modernen Oelfeuerungsanlagen im Haushaltsbereich hin zu kompakten, emissionsarmen Einheiten mit Brennwertnutzung. Einen Durchbruch verspricht der Oelporenbrenner. Die Porenbrennertechnik wurde am LSTM Erlangen entwickelt. Der Oelporenbrenner vereinigt das am EST der RWTH Aachen entwickelte Verdampfungskonzept unter Nutzung der 'Kalte Flamme' mit der Porenbrennertechnik zu einem neuartigen Heizgeraetekonzept, das die hochmodulierbare, schadstoff- und geraeuscharme Verbrennung von Heizoel mit Brennwertnutzung ermoeglicht. Dadurch wird eine Verbesserung des Feuerungswirkungsgrads bis zu 10% erreicht. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-03-15

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

  16. CONTROL OF POLLUTANT EMISSIONS IN NATURAL GAS DIFFUSION FLAMES BY USING CASCADE BURNERS

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Ala Qubbaj

    2001-12-30

    The goal of this exploratory research project is to control the pollutant emissions of diffusion flames by modifying the air infusion rate into the flame. The modification was achieved by installing a cascade of venturis around the burning gas jet. The basic idea behind this technique is controlling the stoichiometry of the flame through changing the flow dynamics and rates of mixing in the combustion zone with a set of venturis surrounding the flame. A natural gas jet diffusion flame at burner-exit Reynolds number of 5100 was examined with a set of venturis of specific sizes and spacing arrangement. The thermal and composition fields of the baseline and venturi-cascaded flames were numerically simulated using CFD-ACE+, an advanced computational environment software package. The instantaneous chemistry model was used as the reaction model. The concentration of NO was determined through CFD-POST, a post processing utility program for CFD-ACE+. The numerical results showed that, in the near-burner, midflame and far-burner regions, the venturi-cascaded flame had lower temperature by an average of 13%, 19% and 17%, respectively, and lower CO{sub 2} concentration by 35%, 37% and 32%, respectively, than the baseline flame. An opposite trend was noticed for O{sub 2} concentration; the cascaded flame has higher O{sub 2} concentration by 7%, 26% and 44%, in average values, in the near-burner, mid-flame and far-burner regions, respectively, than in the baseline case. The results also showed that, in the near-burner, mid-flame, and far-burner regions, the venturi-cascaded flame has lower NO concentrations by 89%, 70% and 70%, in average values, respectively, compared to the baseline case. The numerical results substantiate that venturi-cascading is a feasible method for controlling the pollutant emissions of a burning gas jet. In addition, the numerical results were useful to understand the thermo-chemical processes involved. The results showed that the prompt-NO mechanism

  17. Pluto: new modulating oil-burner for low-power operation; Pluto: Neuer modulierender Oelbrenner kleiner Leistung

    Energy Technology Data Exchange (ETDEWEB)

    Wueest, J.

    2002-07-01

    Starting from a existing Kerosene burner, a modulating oil burner suitable for light and oeko oil was developed for low power operation. This burner combines the advantages of vaporising burner, premix burner and surface burner. This burner stands for low pollutant emission, extremely low operating noise for use in living rooms and reliable modulation of load in the range of e.g. 6 to 16,5 kW, or 3 to 9 kW. The paper presents principles of function and most important features. (orig.) [German] Ausgehend von einem bestehenden Kerosinbrenner wurde ein modulierender Oelbrenner mit kleiner Leistung entwickelt. Er vereint die Vorteile von Verdampfungs-, Premix- und Oberflaechen-Brenner. Der modulierende Oelbrenner eignet sich fuer Heizoel EL sowie Oeko-Oel. Er zeichnet sich aus durch niedrige Schadstoffemissionen und geraeuscharmen Betrieb sowie durch zuverlaessige und stoerungsfreie Modulation der Leistung im Bereich von z.B. 6,0 bis 16,5 kW, oder 3 bis 9 kW. Der Vortrag praesentiert das Funktionsprinzip sowie die wesentlichen Merkmale dieses Brenners. (orig.)

  18. Les perspectives nutritionnelles offertes par les OGM en alimentation humaine

    Directory of Open Access Journals (Sweden)

    Pascal Gérard

    2004-03-01

    Full Text Available Une étude des brevets récents, des publications scientifiques ainsi que des documents présentant les projets des firmes de biotechnologie constituent la base de cet article qui présente les perspectives de développement en alimentation humaine des organismes génétiquement modifiés (OGM présentant un intérêt nutritionnel. Si l’on trouve dans les brevets et les publications scientifiques des applications qui concernent l’amélioration ou l’enrichissement de la composition en macro- et micronutriments, ces applications restent curieusement à l’état de projets, très loin de la mise sur le marché. Les critiques aussi bien que les louanges dont sont l’objet les rares cas dont on pourrait envisager une mise en œuvre à moyen terme, comme le « riz doré », sont aussi injustifiées et excessives les unes que les autres. Les violentes polémiques autour des OGM risquent de handicaper le développement d’une technique puissante, qui n’est certes pas indispensable pour apporter une solution à l’éradication de la faim dans le monde, mais qui peut apporter des améliorations à la nutrition des populations, aussi bien des populations des pays en développement que des pays développés.

  19. The development of low NOx burners under the IEA Coal Combustion Sciences agreement

    Energy Technology Data Exchange (ETDEWEB)

    Whaley, H. [CANMET Energy Technology Centre, Ottawa, Ontario (Canada)

    1997-09-01

    Canada has been involved in the International Energy Agency (IEA) implementing agreement on coal combustion sciences since 1985. The other countries belonging to this agreement are Australia, Germany, Denmark, Finland, Italy, the Netherlands, Sweden, the United Kingdom and the US. There are two operating annexes, the first, Annex 1 being task-shared, in which designated research projects within the participating countries are reported on an annual basis. Annex 2 is cost-shared and the research is conducted at the International Flame Research Foundation (IFRF) in the Netherlands and paid for by the participants, Canada, Germany, the Netherlands and the UK. The objectives of Annex 2 are to develop advanced low NOx coal burners for power boilers and to characterize their performance with a wide range of coals and coal blends. Two burners have been selected as showing great promise in suppressing NOx formation, thereby reducing emissions to below regulatory levels. One is an aerodynamically air-staged burner (AASB) and the other an internally fuel-staged burner (IFSB). Both can utilize a single boiler entry port, which makes them ideal for retrofitting, the former relies on combustion air staging, the latter on fuel staging or reburning. The IFSB, when developed to a commercial stage, is anticipated to meet projected Canadian NOx regulations for the foreseeable future. Supplementary aspects of the program have been coal characterization, ash behavior and deposition, advanced in-flame measurement technique development and validation data bases for flame, combustion and NOx modeling. This presentation will focus on the two low NOx burners developed under the Annex 2 program.

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

    KAUST Repository

    Kim, Daejoong

    2009-11-10

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

  1. Application of a Central Composite Design for the Study of NOx Emission Performance of a Low NOx Burner

    Directory of Open Access Journals (Sweden)

    Marcin Dutka

    2015-04-01

    Full Text Available In this study, the influence of various factors on nitrogen oxides (NOx emissions of a low NOx burner is investigated using a central composite design (CCD approach to an experimental matrix in order to show the applicability of design of experiments methodology to the combustion field. Four factors have been analyzed in terms of their impact on NOx formation: hydrogen fraction in the fuel (0%–15% mass fraction in hydrogen-enriched methane, amount of excess air (5%–30%, burner head position (20–25 mm from the burner throat and secondary fuel fraction provided to the burner (0%–6%. The measurements were performed at a constant thermal load equal to 25 kW (calculated based on lower heating value. Response surface methodology and CCD were used to develop a second-degree polynomial regression model of the burner NOx emissions. The significance of the tested factors over their respective ranges has been evaluated using the analysis of variance and by the consideration of the coefficients of the model equation. Results show that hydrogen addition to methane leads to increased NOx emissions in comparison to emissions from pure methane combustion. Hydrogen content in a fuel is the strongest factor affecting NOx emissions among all the factors tested. Lower NOx formation because of increased excess air was observed when the burner was fuelled by pure methane, but this effect diminished for hydrogen-rich fuel mixtures. NOx emissions were slightly reduced when the burner head was shifted closer to the burner outer tube, whereas a secondary fuel stream provided to the burner was found to have no impact on NOx emissions over the investigated range of factors.

  2. A posteriori testing of algebraic flame surface density models for LES

    Science.gov (United States)

    Ma, T.; Stein, O. T.; Chakraborty, N.; Kempf, A. M.

    2013-06-01

    In the application of Large Eddy Simulation (LES) to premixed combustion, the unknown filtered chemical source term can be modelled by the generalised flame surface density (FSD) using algebraic models for the wrinkling factor Ξ. The present study compares the behaviour of the various models by first examining the effect of sub-grid turbulent velocity fluctuation on Ξ through a one-dimensional analysis and by the LES of the ORACLES burner (Nguyen, Bruel, and Reichstadt, Flow, Turbulence and Combustion Vol. 82 [2009], pp. 155-183) and the Volvo Rig (Sjunnesson, Nelsson, and Max, Laser Anemometry, Vol. 3 [1991], pp. 83-90; Sjunnesson, Henrikson, and Löfström, AIAA Journal, Vol. 28 [1992], pp. AIAA-92-3650). Several sensitivity studies on parameters such as the turbulent viscosity and the grid resolution are also carried out. A statistically 1-D analysis of turbulent flame propagation reveals that counter gradient transport of the progress variable needs to be accounted for to obtain a realistic flame thickness from the simulations using algebraic FSD based closure. The two burner setups are found to operate mainly within the wrinkling/corrugated flamelet regime based on the premixed combustion diagram for LES (Pitsch and Duchamp de Lageneste, Proceedings of the Combustion Institute, Vol. 29 [2002], pp. 2001-2008) and this suggests that the models are operating within their ideal range. The performance of the algebraic models are then assessed by comparing velocity statistics, followed by a detailed error analysis for the ORACLES burner. Four of the tested models were found to perform reasonably well against experiments, and one of these four further excels in being the most grid-independent. For the Volvo Rig, more focus is placed upon the comparison of temperature data and identifying changes in flame structure amongst the different models. It is found that the few models which largely over-predict velocities in the ORACLES case and volume averaged ? in a

  3. GABLS3-LES Intercomparison Study

    NARCIS (Netherlands)

    Basu, S.; Holtslag, A.A.M.; Bosveld, F.C.

    2012-01-01

    Recently, a large-eddy simulation (LES) intercomparison study was organized under the auspices of the GEWEX Atmospheric Boundary Layer Study (GABLS). Eleven LES modelling groups around the world participated in this study to model a baroclinic, mid-latitude nighttime stable boundary layer utilizing

  4. Les infections nosocomiale

    OpenAIRE

    AMMOLR, Naima; ZEKRI, DjaIeI; Lazreg, Mohammed

    2006-01-01

    L'infection hospitalière est un phénomène grave et coûteux pour la société et pour le malade; • elle prolonge la durée de séjours; • augmente la consommation thérapeutique ( antibiotique, antalgique...); • entraîne une mobilisation excessive du personnel; • nuit la réputation du personnel soignant et de l'établissement; • multiplie l'évaluation du coût de prise en charge; • induit des séquelles neurologiques irréversibles. Mieux vaut investir dans les mesures de préven...

  5. Les infections nosocomiale

    OpenAIRE

    AMMOLR, Naima; ZEKRI, DjaIeI; Lazreg, Mohammed

    2006-01-01

    L'infection hospitalière est un phénomène grave et coûteux pour la société et pour le malade; • elle prolonge la durée de séjours; • augmente la consommation thérapeutique ( antibiotique, antalgique...); • entraîne une mobilisation excessive du personnel; • nuit la réputation du personnel soignant et de l'établissement; • multiplie l'évaluation du coût de prise en charge; • induit des séquelles neurologiques irréversibles. Mieux vaut investir dans les mesures de préven...

  6. Les lueurs des sables

    CERN Multimedia

    Les lueurs des sables

    2013-01-01

    Two CERN ladies are getting ready for the “Trophée Roses des Sables” rally adventure: Julie and Laetitia are finalizing the last details before setting off on Monday 7th October 2013. Julie from EN-MEF group and Laetitia from DGS-SEE group, met at the CERN Rugby club. This year, they are participating in the 100 % female rally which will take place in Morocco from 10 to 20 October. They will be carrying along 100 kg of humanitarian donation for children such as some clothes, books and medical material. Do not hesitate to show your support at their farewell party to be held on Monday 7 October, from 4 to 6 pm in front of the St Genis-Pouilly Mairie (city Hall). Follow their exciting adventure on the blog leslueursdessables.trophee-roses-des-sables.org and on their association’s Facebook page Les Lueurs des Sables.

  7. Les plans de gestion de crises dans les pays francophones

    OpenAIRE

    Barkaoui, Houssem; Guinet, Alain; Tao, Wang; Meskens, Nadine

    2016-01-01

    International audience; La gestion des catastrophes, appelée plus communément gestion des situations d'urgences ou encore gestion de crises, est la discipline qui s'intéresse à l'évaluation des menaces et de leurs risques relatifs ainsi qu'aux stratégies mises en oeuvre afin d'en limiter l'occurrence ou les conséquences en cas de survenue. Dans ce papier, nous allons étudier le cadre réglementaire et les mesures prises par les gouvernements pour gérer des situations exceptionnelles de crises ...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-12-15

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

  9. Les jardins de la physique

    CERN Document Server

    Allemand, Luc

    2017-01-01

    À l'écart du monde, loin des laboratoires, en contact avec la nature, des savants réputés du monde entier viennent enseigner les grands sujets de la physique et partager les dernières avancées avec de nombreux élèves. À l'écart du monde, loin des laboratoires, en contact avec la nature, des savants réputés du monde entier viennent enseigner les grands sujets de la physique et partager les dernières avancées avec de nombreux élèves. Ces hauts-lieux sont propices à la méditation et procurent autant d'opportunités de rencontres et d'échanges. La liberté de pensée qui y règne permet d'explorer de nouvelles pistes pour la physique de demain. Car les grandes découvertes surviennent rarement comme des illuminations : elles résultent plutôt de lentes maturations, accompagnées de travail acharné et de discussions suivies. De tels lieux existent depuis les années 1950 en France : l'Institut d'Études scientifiques de Cargèse, en Corse, et l'École de Physique des Houches, dans les Alpes, ...

  10. Experimental data regarding the characterization of the flame behavior near lean blowout in a non-premixed liquid fuel burner

    Directory of Open Access Journals (Sweden)

    Maria Grazia De Giorgi

    2016-03-01

    The data are related to the research article “Image processing for the characterization of flame stability in a non-premixed liquid fuel burner near lean blowout” in Aerospace Science and Technology [1].

  11. Les incentives dans les enquêtes en ligne

    OpenAIRE

    Solène Guillemot

    2013-01-01

    Ce mémoire présente les recherches antérieures d'auteurs s'intéressant aux incentives dans les études marketing et une expérimentation cherchant à vérifier les impacts, à la fois positifs et négatifs, des incentives dans les enquêtes quantitatives en ligne. Ainsi, un questionnaire a été administré par emailing à deux groupes, l'un recevant la possibilité de participer à un tirage au sort (incentive de l'étude), et l'autre n'ayant pas cette possibilité. Il s'agissait dans un premier temps de v...

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

    OpenAIRE

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

    2013-01-01

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

  13. Les chercheurs inquiets malgre les promesses de Claudie Haignere

    CERN Multimedia

    2003-01-01

    "Le 9 avril, lors d'un colloque sur l'innovation, la ministre deleguee a la recherche et aux nouvelles technologies a annonce, "en plein accord, dit-elle, avec le premier ministre", que "les etablissements publics a caractere scientifique et technologique (EPST) ne connaitront en 2003 aucune nouvelle annulation de credits de paiement et d'autorisations de programme" et que "les reserves de precaution sont entierement levees" (1 page).

  14. Industrial thermal oxidation with an innovative burner management system; Industrielle thermische Nachverbrennung mit innovativem Brenner-Managementsystem

    Energy Technology Data Exchange (ETDEWEB)

    Gnoss, T. [Siemens Building Technologies HVAC Product GmbH, Rastatt (Germany); Pilz, R. [Control and Heating-Systems, Felsberg-Gensungen (Switzerland); Saenger, P. [Siemens Building Technologies HVAC Product GmbH, Frankfurt am Main(Germany)

    2006-06-15

    In view of rising energy costs and the emission limits stipulated by the latest 'TA-Luft' (Technical Directive: Prevention of Air Pollution) and 'BImSchV' (Federal Immission Control Ordinance in force in Germany), industrial thermal oxidation plants must be either completely replaced or a new burner system must be installed to ensure compliance with the latest environmental standards that demand restriction of pollutant emissions. Replacement of the original burner control system by a state-of-the-art burner management system improves not only the combustion process and the flue gas quality but also saves energy and thus costs through the use of a thermal incinerator. One of the key features of a thermal oxidation plant is a new technology used for controlling and monitoring the burner. The following article examines the innovative LMV5.. burner management system which offers a host of functions, such as burner control, electronic fuel / air ratio control, valve proving and load control - components which, previously, had to be separately assembled and electrically interconnected. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-12-01

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

  16. Experimental Study of Pre-mixed Flames on a Multi-Hole Matrix Burner

    Directory of Open Access Journals (Sweden)

    Vasudevan Raghavan

    2012-05-01

    Full Text Available This paper deals with an experimental investigation of the flame characteristics of premixed Liquefied Petroleum Gas (LPG - air mixtures with different equivalence ratios on a multi-hole matrix burner. Lowest possible fuel-lean mixing conditions are envisaged. Results show that the flame pattern changes into four different types which are oscillatory flames in the middle region, flames with oscillations along the centerline, flames with very little oscillations and stable flames from all the holes. Species concentration measurements are performed with the help of  gas analyzer and the results show that the concentrations of carbon-monoxide and oxygen decreases, whereas that of carbon-dioxide and nitric oxide increases with increase in the volumetric flow rate of LPG and air mixture. In addition to this, temperature measurements are carried out using a K-type thermocouple over the burner surface at different heights. Temperature contours for each plane have been presented.

  17. Self-inflicted Firearm Discharge from Heating Using a Gas Burner.

    Science.gov (United States)

    Osawa, Motoki; Matsushima, Yutaka; Kumar, Alok; Tsuboi, Akio; Kakimoto, Yu; Satoh, Fumiko

    2016-05-01

    A male in his 70s was found lying dead in the living room of his house. A gunshot entrance wound was observed in the left orbit, with a lead slug and wadding left in the skull, which exhibited fatal cranio-cerebral trauma. A cartridge had been discharged from a handmade launcher, or zip gun, that had been fixed to a spare gun barrel on a pipe chair, by heating the launcher from the side using a gas burner. The deceased had owned guns for hunting in the past and had returned the license, but he had retained a spare barrel and live cartridges at home. In this unique case of suicide, a zip gun was discharged by heating with a gas burner. © 2016 American Academy of Forensic Sciences.

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

    KAUST Repository

    Tran, Vu Manh

    2015-10-22

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

  19. Adapter for converting an oil burner head for burning of pulverized coal

    Energy Technology Data Exchange (ETDEWEB)

    Musil, J.E.

    1988-03-29

    This patent describes a burner head means forming a primary air passage in the burner head including a portion of generally circular configuration in cross-section having openings uniformally circularly disposed about its periphery, and a manifold effective to envelope the primary air passage means. The manifold has inlet means for connection to a source of pulverized coal and air, internal coal and air passages downstream of the inlet effective to divide incoming coal and air into a plurality of discrete streams thereof, and a manifold coal and air outlet opening from each coal and air passage. The manifold outlet openings each are in communication with a duct means having an outlet discharging into one of the openings about the periphery of the primary air passage means.

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

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

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

  1. Interaction of turblence and chemistry in a low-swirl burner

    Science.gov (United States)

    Bell, J. B.; Cheng, R. K.; Day, M. S.; Beckner, V. E.; Lijewski, M. J.

    2008-07-01

    New combustion systems based on ultra-lean premixed combustion have the potential for dramatically reducing pollutant emissions in transportation systems, heat, and stationary power generation. However, lean premixed flames are highly susceptible to fluid-dynamical combustion instabilities, making robust and reliable systems difficult to design. Low-swirl burners are emerging as an important technology for meeting design requirements in terms of both reliability and emissions for next-generation combustion devices. In this paper, we present simlations of a laboratory-scale low-swirl burner using detailed chemistry and transport without incorporating explicit models for turbulence or turbulence/chemistry interaction. We consider two fuels, methane and hydrogen, each at two turbulent intensities. Here we examine some of the basic properties of the flow field and the flame structure. We focus on the differences in flame behavior for the two fuels, particularly on the hydrogen flame, which burns with a cellular structures.

  2. Computational Fluid Dynamics Based Investigation of Sensitivity of Furnace Operational Conditions to Burner Flow Controls

    Energy Technology Data Exchange (ETDEWEB)

    Marc Cremer; Dave Wang; Connie Senior; Andrew Chiodo; Steven Hardy; Paul Wolff

    2005-07-01

    This is the Final Technical Report for DOE Cooperative Agreement No: DE-FC26-02NT41580. The goal of this project was to systematically assess the sensitivity of furnace operational conditions to burner air and fuel flows in coal fired utility boilers. The focus of this project was to quantify the potential impacts of ''fine level'' controls rather than that of ''coarse level'' controls (i.e. combustion tuning). Although it is well accepted that combustion tuning will generally improve efficiency and emissions of an ''out of tune'' boiler, it is not as well understood what benefits can be derived through active multiburner measurement and control systems in boiler that has coarse level controls. The approach used here was to utilize existing baseline furnace models that have been constructed using Reaction Engineering International's (REI) computational fluid dynamics (CFD) software. Using CFD analyses provides the ability to carry out a carefully controlled virtual experiment to characterize the sensitivity of NOx emissions, unburned carbon (UBC), furnace exit CO (FECO), furnace exit temperature (FEGT), and waterwall deposition to burner air and fuel flow rates. The Electric Power Research Institute (EPRI) provided co-funding for this program, and instrument and controls experts from EPRI's Instrument and Controls (I&C) Center have been active participants in this project. CFD simulations were completed for five coal fired boilers as planned: (1) 150 MW wall fired, (2) 500 MW opposed wall fired, (3) 600 MW T-Fired, (4) 330 MW cyclone-fired, and (5) 200 MW T-Fired Twin Furnace. In all cases, the unit selections were made in order to represent units that were descriptive of the utility industry as a whole. For each unit, between 25 and 44 furnace simulations were completed in order to evaluate impacts of burner to burner variations in: (1) coal and primary air flow rate, and (2) secondary air flow

  3. Les êtres collectifs en question

    OpenAIRE

    Angeletti, T.; Berlan, A.

    2015-01-01

    Dans quelles situations les individus se retrouvent-ils confrontés à des êtres, des institutions ou des systèmes qui les dépassent ? Comment y font-ils référence ? Quelles solutions théoriques les sciences sociales mobilisent-elles pour en parler ? Ce numéro regroupe des contributions empiriques et théoriques proposant d’étudier et d’expliciter les modes d’existence et d’apparition des êtres collectifs, quand ils sont envisagés comme des vecteurs d’action. Ce faisant, il s’agit de reposer la ...

  4. Les stalles d’Entremont

    OpenAIRE

    Chassany, Chloé

    2010-01-01

    Les stalles sont un rare exemple de siège liturgique. On les trouve dans le chœur des sanctuaires où se réunissaient les communautés pour célébrer collectivement l’office. Les stalles datées du début du XVIe siècle, conservées dans l’église d’Entremont en Haute Savoie, n’ont jamais fait l’objet d’une étude approfondie. La première partie du mémoire réunit le bilan des recherches de première année de master, une synthèse historiographique du mobilier liturgique savoyard ainsi que l’histoire co...

  5. Information sur les technologies nucleaires

    CERN Multimedia

    2002-01-01

    "La base Inis (International Nuclear Information System) de l'Agence Internationale d'Energie Atomique (IAEA) dispose desormais de liens vers les textes complets de documents internationaux" (1 paragraph).

  6. Premixed Combustion of Kapok (ceiba pentandra) seed oil on Perforated Burner

    OpenAIRE

    I.K.G. Wirawan; I. N. G. Wardana; Rudy Soenoko; Slamet Wahyudi

    2014-01-01

    Availability of fossil fuels in the world decrease gradually due to excessive fuel exploitation. This situations push researcher to look for alternative fuels as a source of renewable energy, one of them is kapok (ceiba pentandra) seed oil. The aim this study was to know the behavior of laminar burning velocity, secondary Bunsen flame with open tip, cellular and triple flame. Premixed combustion of kapok seed oil was studied experimentally on perforated burner with equivalence ratio (φ) varie...

  7. Optimum feeding rate of solid hazardous waste in a cement kiln burner

    OpenAIRE

    2013-01-01

    Solid hazardous waste mixed with wood chips (SHW) is a partly CO2 neutral fuel, and hence is a good candidate for substituting fossil fuels like pulverized coal in rotary kiln burners used in cement kiln systems. SHW is used in several cement plants, but the optimum substitution rate has apparently not yet been fully investigated. The present study aims to find the maximum possible replacement of coal by SHW, without negatively affecting the product quality, emissions and overall operation of...

  8. The porous burner - concept, technique, and fields of application; Der Porenbrenner - Konzept, Technik und Anwendungsgebiete

    Energy Technology Data Exchange (ETDEWEB)

    Durst, F.; Kesting, A.; Moessbauer, S.; Pickenaecker, K.; Pickenaecker, O.; Trimis, D. [Erlangen Univ. (Germany). Lehrstuhl fuer Stroemungsmechanik

    1997-06-01

    In its efforts to optimize combustion processes, the Institute of Fluid Dynamics in Erlangen (LSTM-Erlangen) has succeeded in developing the technology of combustion in a porous medium. This novel technique stands out for its advantages that no other modern burner technology can show so far. These advantages can be summarized by an extremely high, infinitely variable power dynamic range combined with minimum waste gas emissions and a very compact size. The concept of porous burner technology is briefly described in the present article. Starting with general principles, the basic design as well as the structures and the properties of materials that are suitable for the combustion in porous media are described. Additionally, some important fields of application for this novel technology are outlined including a precompetitive latent heat gas boiler. Moreover, first studies showing the possibility of applying the porous burner technology in gas turbine furnaces or as radiation burners, respectively, were performed. (orig.) [Deutsch] Im Zuge der Optimierung von Verbrennungsprozessen gelang am LSTM-Erlangen die Entwicklung der neuartigen Porenbrennertechnologie, die sich durch Vorteile auszeichnet, welche derart zur Zeit keine andere moderne Brennertechnologie aufweist. Diese Vorteile koennen mit einer aeusserst kompakten Bauweise und einer extrem hohen, stufenlosen Leistungsdynamik bei gleichzeitig minimaler Schadstoffemission charakterisiert werden. Das Konzept der Porenbrennertechnik wird in dem vorliegenden Artikel kurz vorgestellt. Ausgehend von allgemeinen Grundlagen werden neben den konstruktiven Grundueberlegungen und den Arten und Eigenschaften poroeser Strukturen, die sich fuer die Verbrennung in poroesen Medien eignen, einige wichtige Anwendungsgebiete dieser neuartigen Technologie dargestellt. Im Bereich der Haushaltstechnik wird ein vorwettbewerblicher Brennwert-Gas-Wassererhitzer vorgestellt, der auf dem Porenbrennerkonzept basiert. Ebenso werden erste

  9. Blower burner market development. Boiler management by electronics; Ventilatorbrandermarkt in beweging. Elektronica maakt ketelmanagement mogelijk

    Energy Technology Data Exchange (ETDEWEB)

    Harms, R. [Monarch Nederland, Diemen (Netherlands)

    2004-09-01

    A brief overview is given of the developments in the market for blower burners. New technology concerns digital control techniques. [Dutch] De Nederlandse ventilatorbrandermarkt ondergaat de laatste jaren aanzienlijke wijzigingen. 25 jaar geleden trof men tientallen producenten en importeurs van gas-en oliebrandersnaar op een vakbeurs voor verwarming. Nu zijn er nog maar tien. Technische ontwikkelingen spelen zich op dit moment af op het terrein van de digitale besturingstechniek wat extra mogelijkheden biedt.

  10. An Advanced Option for Sodium Cooled TRU Burner Loaded with Uranium-Free Fuels

    Energy Technology Data Exchange (ETDEWEB)

    You, WuSeung; Hong, Ser Gi [Kyung Hee University, Yongin (Korea, Republic of)

    2015-05-15

    The sodium cooled fast reactors of this kind that are called burners are designed to have low conversion ratio by reducing fuel volume fraction or reducing neutron leakage or increasing neutron absorption. However, the typical SFR burners have a limited ability of TRU burning rate due to the fact that they use metallic or oxide fuels containing fertile nuclides such as {sup 238}U and {sup 232}Th and these fertile nuclides generate fissile nuclides through neutron capture even if they are designed to have low conversion ratio (e.g., 0.6). To further enhance the TRU burning rate, the removal of the fertile nuclides from the initial fuels is required and it will accelerate the reduction of TRUs that are accumulated in storages of LWR spent fuels. However, it has been well-known 4 that the removals of the fertile nuclides from the fuel degrade the inherent safety of the SFR burner cores through the significant decrease of the fuel Doppler effect, the increase of sodium void reactivity worth, and reduction of delayed neutron fraction. In this work, new option for the sodium cooled fast TRU burner cores loaded with fertile-free metallic fuels was proposed and the new cores were designed by using the suggested option. The cores were designed to enhance the inherent safety characteristics by using axially central absorber region and 6 or 12 ZrH1.8 moderator rods per fuel assembly. For each option, we considered two different types of fertile-free ternary metallic fuel (i.e., TRU-W-10Zr and TRU-Ni-10Zr). Also, we performed the BOR (Balance of Reactivity) analyses to show the self-controllability under ATWS as a measure of inherent safety. The core performance analysis showed that the new cores using axially central absorber region substantially improve the core performance parameters such as burnup reactivity swing and sodium void reactivity worth.

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

    OpenAIRE

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

    2013-01-01

    Background: Residential natural gas cooking burners (NGCBs) can emit substantial quantities of pollutants, and they are typically used without venting range hoods. Objective: We quantified pollutant concentrations and occupant exposures resulting from NGCB use in California homes. Methods: A mass-balance model was applied to estimate time-dependent pollutant concentrations throughout homes in Southern California and the exposure concentrations experienced by individual occupants. We estimated...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-01

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

  13. Les stocks dans la crise.

    OpenAIRE

    de Rougemont, P.

    2011-01-01

    Fin 2008, un mouvement de déstockage massif et mondial contribue à la forte contraction de l’activité et du commerce international. Ce mouvement est sans doute accentué par les contraintes financières sur les entreprises et par la transmission du choc le long de chaînes de production mondialisées. En sens inverse, mi-2009, le ralentissement du déstockage contribue à une reprise en « V ».

  14. Winter School Les Houches

    CERN Document Server

    Lannoo, Michel; Bastard, Gérald; Voos, Michel; Boccara, Nino

    1986-01-01

    The Winter School held in Les Houches on March 12-21, 1985 was devoted to Semiconductor Heterojunctions and Superlattices, a topic which is recognized as being now one of the most interesting and active fields in semiconductor physics. In fact, following the pioneering work of Esaki and Tsu in 1970, the study of these two-dimensional semiconductor heterostructures has developed rapidly, both from the point of view of basic physics and of applications. For instance, modulation-doped heterojunctions are nowadays currently used to investigate the quantum Hall effect and to make very fast transistors. This book contains the lectures presented at this Winter School, showing in particular that many aspects of semiconductor heterojunctions and super­ lattices were treated, extending from the fabrication of these two-dimensional systems to their basic properties and applications in micro-and opto-electron­ ics. Among the subjects which were covered, one can quote as examples: molecular beam epitaxy and metallorgani...

  15. Combustion characteristics of low concentration coal mine methane in divergent porous media burner

    Institute of Scientific and Technical Information of China (English)

    Lin Baiquan; Dai Huaming⇑; Wang Chaoqun; Li Qingzhao; Wang Ke; Zheng Yuanzhen

    2014-01-01

    Low-concentration methane (LCM) has been one of the biggest difficulties in using coal mine methane. And previous studies found that premixed combustion in porous media is an effective method of low cal-orific gas utilization. This paper studied the combustion of LCM in a divergent porous medium burner (DPMB) by using computational fluid dynamics (CFD), and investigated the effect of gas initial tempera-ture on combustion characteristic, the distribution of temperature and pollutant at different equivalence ratios in detail. Besides, the comparison of divergent and cylindrical burners was also performed in this paper. The results show that:the peak temperature in DPMB increases as the increasing of equivalence ratio, which is also suitable for the outlet NO discharge;the linear correlation is also discovered between peak temperature and equivalence ratios;NO emission at the initial temperature of 525 K is 5.64 times, larger than NO emission at the initial temperature of 300 K. Thus, it is preferable to balance the effect of thermal efficiency and environment simultaneously when determining the optimal initial temperature range. The working parameter limits of divergent burner are wider than that of cylindrical one which contributes to reducing the influence of LCM concentration and volume fluctuation on combustion.

  16. THEORETICAL ANALYSIS AND PRACTICE ON THE SELECTION OF KEY PARAMETERS FOR HORIZONTAL BIAS BURNER

    Institute of Scientific and Technical Information of China (English)

    刘泰生; 许晋源

    2003-01-01

    The air flow ratio and the pulverized-coal mass flux ratio between the rich and lean sides are the key parameters of horizontal bias burner. In order to realize high combustion efficiency, excellent stability of ignition, low NOx emission and safe operation, six principal demands are presented on the selection of key parameters. An analytical model is established on the basis of the demands, the fundamentals of combustion and the operation results. An improved horizontal bias burner is also presented and applied. The experiment and numerical simulation results show the improved horizontal bias burner can realize proper key parameters, lower NOx emission, high combustion efficiency and excellent performance of part load operation without oil support. It also can reduce the circumfluence and low velocity zone existing at the downstream sections of vanes, and avoid the burnout of the lean primary-air nozzle and the jam in the lean primary-air channel. The operation and test results verify the reasonableness and feasibility of the analytical model.

  17. Measurements of Non-reacting and Reacting Flow Fields of a Liquid Swirl Flame Burner

    Institute of Scientific and Technical Information of China (English)

    CHONG Cheng Tung; HOCHGREB Simone

    2015-01-01

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

  18. A Development and Application of a Ladle Regenerative Burner System for a Steel Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Seong Soo [POSCO, Pohang (Korea); Park, Heung Soo [Research Institute of Industrial Science and Technology, Pohang (Korea)

    2001-06-01

    This study developed a self-model on a regenerative ladle heating system, 300 millions kcal/hr of a burning capacity using COG fuel, and conducted a performance test through applying it to a field. The model has a structure, which can tilt through loading a mixed burner with a high-speed spay nozzle on a ladle cover, as well as a fixed duct and can inhale and exhaust the air through the inside of a rotating duct built horizontally. The regenerative system is designed of a rectangular parallelepiped, 0.56 m{sup 3} of an inside volume, and uses 25 mm diameter of a ceramic ball as a regenerating material. This study got conclusions through operating the installed system in field and testing burning as follows: 1) The structure of a burner and a duct system selected through this study is a vertical burning regenerative ladle heating system and suitable to a space application and an operation; 2) The self-designed burner shows the stable burning state, its ignition is excellent in high loading time, and the designed speed of a moving fluid in spray is adequate; 3) In the condition of the lowest absorption, the preheating temperature of burning air reaches to 530 deg C, and the sensible heat of burning exhaust gas can be recovered over 50%; 4) The saving effect of fuel gas due to the installation of this system is measured minimum 25%{approx}30%. 3 figs.

  19. Prediction of Excess Air Factor in Automatic Feed Coal Burners by Processing of Flame Images

    Science.gov (United States)

    Talu, Muhammed Fatih; Onat, Cem; Daskin, Mahmut

    2017-05-01

    In this study, the relationship between the visual information gathered from the flame images and the excess air factor λ in coal burners is investigated. In conventional coal burners the excess air factor λ. can be obtained using very expensive air measurement instruments. The proposed method to predict λ for a specific time in the coal burners consists of three distinct and consecutive stages; a) online flame images acquisition using a CCD camera, b) extraction meaningful information (flame intensity and brightness)from flame images, and c) learning these information (image features) with ANNs and estimate λ. Six different feature extraction methods have been used: CDF of Blue Channel, Co-Occurrence Matrix, L ∞-Frobenius Norms, Radiant Energy Signal (RES), PCA and Wavelet. When compared prediction results, it has seen that the use of co-occurrence matrix with ANNs has the best performance (RMSE = 0.07) in terms of accuracy. The results show that the proposed predicting system using flame images can be preferred instead of using expensive devices to measure excess air factor in during combustion.

  20. Mixing and Recirculation Characteristics of A double COncentric Burner with Bluff—Body

    Institute of Scientific and Technical Information of China (English)

    H.K.Ma; C.H.Chiou; 等

    1993-01-01

    The concentric bluff-body jet burner is widely used in industrial combustion systems.This kind of burner often generates a considerably complex recirculation zone behind the bluff body.As a result,the fuel often remains in the recirculation zone,achieving stability of flame.This study investigates,by means of experiments,the variations of the aerodynamics as the fluid is injected into a combustion chamber through a doble concentric burner with a bluff-body.The observation and measurement of the aerodynamics in our experiment are conducted under a cold flow.The controlled parameters in our experiment are:variations in the blockage ratio of the center bluff body,the cone angle of the bluff body,and the velocity ratio(Us/Up) of the secondary jet and primary jet;the injection of helium bubbles into the primary and secondary jets to observe the recirculation zone behind the bluff body;using Tufts for obseving the characteristics of corner recirculation zone in a combustion chamber,measuring the average velocity of each point within the aerodynamics by the 5-hole pitot tube;measuring the distribution of static pressure of the combustion chamber walls with a static pressure tap.

  1. FRACTAL CHARACTERISTICS OF AERODYNAMIC FIELD AT OUTLET OF LOW-NOx COAXIAL SWIRLING BURNER

    Institute of Scientific and Technical Information of China (English)

    WU Jiang; TIAN Feng-guo; ZHANG Ming-chuan; SONG Yu-bao; GAO Mao; YIN Bin

    2004-01-01

    The primary wind of a low-NOx coaxial swirling burner was visualized by using glycol as smog tracer. The information of the visual flow field was input into a computer through image-capturing card with CCD camera as the image-capturing element. The boundary of the visual zone, i.e., the interface of the primary wind and secondary wind was obtained by image processing. The fractal dimension (FD) of the boundary was examined and found to vary from 1.10 to 1.40 with S1, S2 and ζ1. It is concluded that when FD is small, the complex level of the interface is low, and mixture between the primary and secondary wind is weak near the exit of the burner at the initial phase of combustion resulting in stratified flow; when FD is big, mixture becomes strong near the exit of the burner. It is showed that the flow with FD ranging from 1.10 to 1.20 is stratified flow, which is benefical to reduce NOx yield and the flow with FD from 1.25 to 1.40 is mixed flow, producing much NOx. The mechanism of the forming of stratified flow and mixed flow was theoretically analyzed. The corresponding S1, S2 and ζ1 of these flows were given.

  2. CFD prediction of physical field for multi-air channel pulverized coal burner in rotary kiln

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A 3-D numerical simulation with CFX software on physical field of multi-air channel coal burner in rotary kiln was carried out. The effects of various operational and structural parameters on flame feature and temperature distribution were investigated. A thermal measurement was conducted on a rotary kiln (4.5 m in diameter, 90 m in length) with four-air channel coal burner to determine the boundary conditions and to verify the simulation results.The calculation result shows that the distribution of velocity near burner exit is saddle-like; recirculation zones near nozzle and wall are useful for mixture primary air with coal and high temperature fume. A little central airflow can avoid coal backing up and cool nozzle. Adjusting the ratio of internal airflow to outer airflow is an effective and major means to regulate flame and temperature distribution in sintering region. Large whirlcone angle can intensify disturbution range at flame root to accelerate ignition and mixture. Large coal size can reduce high temperature region and result in coal combusting insufficiently. Too much combustion air will lengthen flame and increase heat loss.

  3. "Les Hollande" de Whistler chez Proust

    NARCIS (Netherlands)

    M. van Montfrans

    2011-01-01

    Le rôle que les portraits mondains et les marines de Whistler, l’un des modèles d’Elstir, ont joué dans la Recherche, a fait l’objet de nombreux commentaires. Il n’en est pas de même pour « les Hollande », fruit des séjours fréquents du peintre aux Pays-Bas. Les rares références aux voyages en Holla

  4. Controverses sur les sucres [Controversies about sugars

    Directory of Open Access Journals (Sweden)

    Malika BOUCHENAK

    2016-12-01

    Full Text Available La surconsommation de sucres ajoutés et leurs effets putatifs sur diverses pathologies cardiométaboliques continuent de susciter des controverses. Dans les années 1950, le taux élevé de maladies cardiovasculaires (MCV, chez les hommes Américains a conduit à des études sur le rôle des facteurs alimentaires, tels que le cholestérol, les phytostérols, l'excès de calories, les acides aminés, les graisses, les glucides, les vitamines et les minéraux, à influencer le risque de MCV. Dans les années 60, deux éminents physiologistes, plaidant pour des hypothèses causales divergentes de MCV, John Yudkin a identifié les sucres ajoutés comme agent primaire, tandis que Ancel Keys identifiait les graisses totales, les graisses saturées et le cholestérol alimentaire. Cependant, dans les années 80, peu de scientifiques croyaient que les sucres ajoutés jouaient un rôle important dans la maladie coronarienne, et les premiers conseils nutritionnels de 1980 (1980 Dietary Guidelines for americans étaient axés sur la réduction des graisses totales, des graisses saturées et du cholestérol alimentaire pour la prévention des MCV.

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

    KAUST Repository

    Ismail, Mohamed

    2016-05-04

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

  6. Development of the Radiation Stabilized Distributed Flux Burner, Phase II Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Webb, A.; Sullivan, J.D.

    1997-06-01

    This report covers progress made during Phase 2 of a three-phase DOE-sponsored project to develop and demonstrate the Radiation Stabilized Distributed Flux burner (also referred to as the Radiation Stabilized Burner, or RSB) for use in industrial watertube boilers and process heaters. The goal of the DOE-sponsored work is to demonstrate an industrial boiler burner with NOx emissions below 9 ppm and CO emissions below 50 ppm (corrected to 3% stack oxygen). To be commercially successful, these very low levels of NOx and CO must be achievable without significantly affecting other measures of burner performance such as reliability, turndown, and thermal efficiency. Phase 1 of the project demonstrated that sub-9 ppm NOx emissions and sub-50 ppm CO emissions (corrected to 3% oxygen) could be achieved with the RSB in a 3 million Btu/Hr laboratory boiler using several methods of NOx reduction. The RSB was also tested in a 60 million Btu/hr steam generator used by Chevron for Thermally Enhanced Oil Recovery (TEOR). In the larger scale tests, fuel staging was demonstrated, with the RSB consistently achieving sub-20 ppm NOx and as low as 10 ppm NOx. Large-scale steam generator tests also demonstrated that flue gas recirculation (FGR) provided a more predictable and reliable method of achieving sub-9 ppm NOx levels. Based on the results of tests at San Francisco Thermal and Chevron, the near-term approach selected by Alzeta for achieving low NOx is to use FGR. This decision was based on a number of factors, with the most important being that FGR has proved to be an easier approach to transfer to different facilities and boiler designs. In addition, staging has proved difficult to implement in a way that allows good combustion and emissions performance in a fully modulating system. In Phase 3 of the project, the RSB will be demonstrated as a very low emissions burner product suitable for continuous operation in a commercial installation. As such, the Phase 3 field demonstration

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

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-07-01

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

  8. Une vie active saine pour les enfants et les adolescents

    Science.gov (United States)

    2002-01-01

    De mauvais modes de vie, comme une alimentation malsaine et l’inactivité physique, sont d'importants facteurs contributifs à une augmentation de la morbidité et de la mortalité secondaires à des maladies chroniques à l’âge adulte. Depuis dix ans, on remarque une augmentation du mode de vie sédentaire et de l’obésité chez les enfants et les adolescents, tant en Amérique du Nord qu’ailleurs dans le monde. Les médecins doivent être conscients de l’importance du problème, fournir des conseils de prévention aux familles et promouvoir une vie active saine dans leur pratique.

  9. ["Les Impatients": expression through art].

    Science.gov (United States)

    Lamontagne, Céline; Palardy, Lorraine

    2015-01-01

    The organization called "Les Impatients" was founded in 1992. Using a unique model, Les Impatients welcomes those with mental health issues who would like to express themselves through art. Les Impatients offers free creative workshops and encourages exchanges with the community through the sharing of its participants' creations. The name Les Impatients reinforces the idea that the organization does not consider those attending its workshops as patients, but rather creators who are eager to heal, develop their craft and find their place in society. The participants contribute to the collective objective of breaking down the stigma that surrounds mental illness.Les Impatients collaborates with various mental health organizations in Quebec, such as the Institut universitaire en santé mentale de Montréal (IUSMM) affiliated to the Université de Montréal, Douglas Mental Health University Institute (DMHUI), the Centre de santé et services sociaux Drummond (CSSS Drummond) and the Centre de santé et services sociaux Pierre-Boucher (CSSS Pierre-Boucher). Les Impatients offers more than 48 workshops in eight different locations to around 450 participants each week.Dissemination activities, remarkable events, original projects: Les Impatients stands out through its realizations. Examples are exhibitions, collections of love letters, comic books, CD, concerts, and reading nights. The organization's originality resides in the exploration of the links between the work of the participants and that of professional artists. An illustration of this interest is the annual Parle-moi d'amour auction-exhibition, which has been one of Les Impatients' major events since 1999.As part of its mission, Les Impatients conserves the works of art created by the participants during the workshops. Its collection includes more than 15,000 works of art from Les Impatients as well as pieces donated by collectors of unconventional art, commonly known as "art brut" or "outsider art". The

  10. Max Planck et les quanta

    CERN Document Server

    Boudenot, Jean-Claude

    2016-01-01

    « Les atomes, dit Jean Perrin en 1913, ne sont pas ces éléments éternels et insécables dont l'irréductible simplicité donnait au possible une borne, et, dans leur inimaginable petitesse, nous commençons à pressentir un fourmillement prodigieux de mondes nouveaux ». C'est bien dans un monde totalement nouveau, le monde quantique, que nous a fait pénétrer la découverte des quanta par Max Planck. Son article de 1900 est le déclencheur de l'une des plus grandes révolutions scientifiques de tous les temps. Les trente années qui suivent sont les plus riches de la physique ; Planck, Einstein, Bohr, Sommerfeld, de Broglie, Schrödinger, Heisenberg, Dirac, Born, Pauli… reconstruisent la physique sur de nouvelles bases sur fond de conflit des générations. Le monde est par ailleurs secoué par la guerre, Max Planck est tourmenté et vit des épreuves personnelles dramatiques. C'est l'homme, aussi bien que l'oeuvre, que les auteurs ont tenté de dépeindre dans cet ouvrage. Ils ont également souhait�...

  11. Les énergies renouvelables.

    OpenAIRE

    Gautier, Henri

    2015-01-01

    Voici un livre très utile pour les béotiens qui voudraient aborder la thématique des énergies renouvelables comme introduction, mais également pour les analystes travaillant dans ce domaine comme manuel de référence. En effet, écrit par un praticien de l’énergie et un pédagogue des sciences physiques, cet ouvrage balaie le panel des énergies renouvelables actuellement disponibles en fournissant des indications techniques indispensables sur chaque solution énergétique et des repères utiles sur...

  12. Les enseignements de la catastrophe

    OpenAIRE

    Grünewald, François

    2011-01-01

    Avant le séisme, divers mécanismes de coordination internationale impliquant différentes parties prenantes (donateurs, ONG internationales et nationales, agences des Nations unies, acteurs multilatéraux, Gouvernement d’Haïti, etc.), détentrices de mandats différents avaient été mis sur pied. Même si le dialogue entre les groupes de la société civile haïtienne et les différents fora de coordination internationale ont souvent été difficiles, face à des risques naturels nombreux, des efforts ava...

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

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Ajay; Taylor, Robert

    2013-09-30

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

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

    Directory of Open Access Journals (Sweden)

    Petrović-Bećirović Sanja B.

    2015-01-01

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

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

    Science.gov (United States)

    1990-07-01

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

  16. Numerical Simulation of Oxy-coal Combustion for a Swirl Burner with EDC Model

    Institute of Scientific and Technical Information of China (English)

    崔凯; 刘冰; 吴玉新; 杨海瑞; 吕俊复; 张海

    2014-01-01

    The characteristics of oxy-coal combustion for a swirl burner with a specially designed preheating chamber are studied numerically. In order to increase the accuracy in the prediction of flame temperature and igni-tion position, eddy dissipation concept (EDC) model with a skeletal chemical reaction mechanism was adopted to describe the combustion of volatile matter. Simulation was conducted under six oxidant stream conditions with dif-ferent O2/N2/CO2 molar ratios:21/79/0, 30/70/0, 50/50/0, 21/0/79, 30/0/70 and 50/0/50. Results showed that O2 en-richment in the primary oxidant stream is in favor of combustion stabilization, acceleration of ignition and increase of maximum flame temperature, while the full substitution of N2 by CO2 in the oxidant stream delays ignition and decreases the maximum flame temperature. However, the overall flow field and flame shapes in these cases are very similar at the same flow rate of the primary oxidant stream. Combustion characteristics of the air-coal is similar to that of the oxy-coal with 30%O2 and 70%CO2 in the oxidant stream, indicating that the rear condition is suitable for retrofitting an air-coal fired boiler to an oxy-coal one. The swirl burner with a specially designed preheating chamber can increase flame temperature, accelerate ignition and enhance burning intensity of pulverized coal under oxy-coal combustion. Also, qualitative experimental validation indicated the burner can reduce the overall NOx emission under certain O2 enrichment and oxy-coal combustion conditions against the air-coal combustion.

  17. Comment diffuser les savoirs à travers les Alpes ?

    Directory of Open Access Journals (Sweden)

    Wolfgang Pfefferkorn

    2009-03-01

    Full Text Available CIPRA’s Future in the Alps Project aims at showcasing examples of successful implementation and successful projects in the Alps, and making available to others the extensive pool of experience and practical knowledge that lies in these projects. But how to transfer knowledge in an area of some 14 million inhabitants with several linguistic and cultural regions in which thousands of projects are carried out each year, that all kinds of players who work and life in completely different contexts are able to learn and benefit from one another? How do you go about something like that?Le projet « Avenir dans les Alpes » de la CIPRA (Commission Internationale pour la Protection des Alpes a pour objectif de présenter des exemples de réalisations et de projets réussis dans les Alpes, et de mettre à disposition du public l’ensemble de l’expérience et des connaissances pratiques acquises dans le cadre de ces projets. Cependant, comment transférer les savoirs dans une zone comptant quelque 14 millions d’habitants, composée de plusieurs régions linguistiques et culturelles dans lesquelles des milliers de projets sont menés à bien chaque année, et dont tous les acteurs, qui travaillent et vivent dans des contextes complètement différents, sont capables d’apprendre et de tirer profit les uns des autres ? Comment aborder ce genre de cas ?

  18. Les charniers en Bosnie-Herzégovine. Les crimes contre les survivants

    Directory of Open Access Journals (Sweden)

    Amor Masovic

    2005-04-01

    Full Text Available Amor Masovic, responsable de la commission de recherche des disparus en Bosnie-Herzégovine et ancien responsable de la commission pour l’échange des prisonniers pendant la guerre de 1992-1995, nous présente ensuite un tableau accablant des disparitions dans les guerres récentes en ex-Yougoslavie, et des pratiques pour faire en sorte que ceux-ci ne soient ni retrouvés ni, encore moins, identifiés (d’où des fosses communes de deux types : « primaires » –  où les corps furent enterrés initialement – et « secondaires » – où ces mêmes corps furent ré-enterrés, souvent démembrés, après avoir été déterrés pour être dispersés et moins aisés à repérer. 28 000 des 40 000 disparus ex-Yougoslaves relèvent du conflit en Bosnie et sont à 95 % des civils protégés par les conventions de Genève. Sur les 280 charniers identifiés la plupart se trouvaient à l’arrière et non sur le front et les disparitions sont datables à des périodes de non-combat. Le but de la commission est donc d’abord de retrouver et identifier les morts pour « faire savoir » et permettre le deuil (puisque la barbarisation qui a été exercée est double : contre les victimes et contre leurs familles qui ne peuvent « vivre » tant qu’elles n’ont pas de certitude. En outre, faute de disposition légale et d’une absence de droit spécifique des disparus personne ne peut être incriminé pour une disparition devant le TPIY où les « disparus » ne sont donc pas représentés. Amor Masovic tire quatre conclusions de son exposé : 1 la barbarie exprimée aujourd’hui est pour partie un résultat des manques de la justice à l’égard des crimes de guerre de la seconde guerre mondiale ; 2 la guerre contre les civils augmente en même temps qu’augmentent les dispositions internationales contre ces exactions qui restent donc purement formelles ; 3 en Bosnie, la barbarisation s’est exercée sur les corps des

  19. "Les actants, les acteurs et les figures”, de A. J. Greimas

    OpenAIRE

    Baquero Velásquez Julia Marlén

    1991-01-01

    "Les actants, les acteurs et les figures" es un artículo de carácter teórico en el cual Greimas intenta responder los siguientes interrogantes: ¿Qué se entiende por actantes, actores y figuras? ¿Cómo se diferencian unos de otros? ¿, Cómo se relacionan estos tres conceptos? ¿Qué ubicación tiene cada uno en el marco de la teoría semiótica general? No se puede decir, sin embargo, que tal información se pueda obtener en forma precisa a partir de este texto, quizá debido, por un lado, a que el art...

  20. COAL PARTICLE FLOW PATTERNS FOR O2 ENRICHED, LOW NOx BURNERS

    Energy Technology Data Exchange (ETDEWEB)

    Jennifer L. Sinclair

    2001-09-30

    Over the past year, the hot flow studies have focused on the validation of a novel 2M near-flame combustion furnace. The 2M furnace was specifically designed to investigate burner aerodynamics and flame stability phenomena. Key accomplishments include completion of coal & oxygen mass balance calculations and derivation of emission conversion equations, upgrade of furnace equipment and flame safety systems, shakedown testing and partial completion of a parametric flame stability study. These activities are described in detail below along with a description of the 2M furnace and support systems.

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

    Energy Technology Data Exchange (ETDEWEB)

    Burgoyne, R.M.

    1976-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-02-15

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

  3. Computational Fluid Dynamics Based Investigation of Sensitivity of Furnace Operational Conditions to Burner Flow Controls

    Energy Technology Data Exchange (ETDEWEB)

    Marc Cremer; Kirsi St. Marie; Dave Wang

    2003-04-30

    This is the first Semiannual Technical Report for DOE Cooperative Agreement No: DE-FC26-02NT41580. The goal of this project is to systematically assess the sensitivity of furnace operational conditions to burner air and fuel flows in coal fired utility boilers. Our approach is to utilize existing baseline furnace models that have been constructed using Reaction Engineering International's (REI) computational fluid dynamics (CFD) software. Using CFD analyses provides the ability to carry out a carefully controlled virtual experiment to characterize the sensitivity of NOx emissions, unburned carbon (UBC), furnace exit CO (FECO), furnace exit temperature (FEGT), and waterwall deposition to burner flow controls. The Electric Power Research Institute (EPRI) is providing co-funding for this program, and instrument and controls experts from EPRI's Instrument and Controls (I&C) Center are active participants in this project. This program contains multiple tasks and good progress is being made on all fronts. A project kickoff meeting was held in conjunction with NETL's 2002 Sensors and Control Program Portfolio Review and Roadmapping Workshop, in Pittsburgh, PA during October 15-16, 2002. Dr. Marc Cremer, REI, and Dr. Paul Wolff, EPRI I&C, both attended and met with the project COR, Susan Maley. Following the review of REI's database of wall-fired coal units, the project team selected a front wall fired 150 MW unit with a Riley Low NOx firing system including overfire air for evaluation. In addition, a test matrix outlining approximately 25 simulations involving variations in burner secondary air flows, and coal and primary air flows was constructed. During the reporting period, twenty-two simulations have been completed, summarized, and tabulated for sensitivity analysis. Based on these results, the team is developing a suitable approach for quantifying the sensitivity coefficients associated with the parametric tests. Some of the results of the CFD

  4. Making highly flammable liquid wastes of petrochemical works safe by combustion without burners

    Energy Technology Data Exchange (ETDEWEB)

    Shelygin, B.L.; Bakhirev, V.I.; Gudzyuk, V.L.

    1983-11-01

    At the V.I. Lenin Energy Institute in Ivanov a technological program was implementd for combustion of highly flammable bulk wastes (for example, piperylene fractions) of petrochemical enterprises, with a moisture content of under 10% and mechanical admixtures (particles of catalyst dust) of up to 5%, without the use of burners. In devising the program, the results of mathematical theoretical analysis of pre-igniting preparation of substances to make them safe were utilized as well as the experience acquired in burning petroleum sludge in furnaces with bubbling equipment.

  5. La guitare dans les musiques traditionnelles

    OpenAIRE

    Rougier, Thierry

    2002-01-01

    International audience; Ce que l'organologie classique désigne sous le nom de "guitare" connaît en fait une très grande variété (de forme, d'accord, de mode de jeu) dans les musiques traditionnelles. L'ethnomusicologie rend compte de la continuité entre les cordophones de type guitare, les autres cordophones et les instruments à percussion, sur de nombreux terrains (dans la musique flamenca, brésilienne...)

  6. Validating LES for Jet Aeroacoustics

    Science.gov (United States)

    Bridges, James

    2011-01-01

    Engineers charged with making jet aircraft quieter have long dreamed of being able to see exactly how turbulent eddies produce sound and this dream is now coming true with the advent of large eddy simulation (LES). Two obvious challenges remain: validating the LES codes at the resolution required to see the fluid-acoustic coupling, and the interpretation of the massive datasets that result in having dreams come true. This paper primarily addresses the former, the use of advanced experimental techniques such as particle image velocimetry (PIV) and Raman and Rayleigh scattering, to validate the computer codes and procedures used to create LES solutions. It also addresses the latter problem in discussing what are relevant measures critical for aeroacoustics that should be used in validating LES codes. These new diagnostic techniques deliver measurements and flow statistics of increasing sophistication and capability, but what of their accuracy? And what are the measures to be used in validation? This paper argues that the issue of accuracy be addressed by cross-facility and cross-disciplinary examination of modern datasets along with increased reporting of internal quality checks in PIV analysis. Further, it is argued that the appropriate validation metrics for aeroacoustic applications are increasingly complicated statistics that have been shown in aeroacoustic theory to be critical to flow-generated sound.

  7. Le CERN sous les yeux

    CERN Multimedia

    Lambelet, S

    1984-01-01

    J. Grinevald, A. Gsponer, L. Hanouz et P. Lehmann sortent un livre : "la quadrature du CERN". Ils apportent une vision critique de la physique des particules et entament une réflexion sur les buts de cette science (1 page).

  8. Le clonage somatique : un état des lieux chez les bovins et les petits ruminants

    OpenAIRE

    Heyman, Yvan; Chavatte-Palmer, Pascale; Vignon, Xavier; Richard, Christophe; Renard, Jean Paul

    2005-01-01

    Parmi les récentes biotechnologies de la reproduction chez les mammifères d’élevage, le clonage par transfert de noyaux somatiques constitue un pas en avant depuis la naissance de la brebis Dolly. Cet article fait le point sur les résultats actuels obtenus dans le monde chez les bovins et les petits ruminants, les limites de la technique et les applications potentielles. L’efficacité globale du clonage (nombre de jeunes nés /nombre d’embryons reconstitués) reste encore faible (≤ 7 %), mais el...

  9. Les consequences de l'echouement de l'Amoco Cadiz" sur les peuplements algaux exploitables

    OpenAIRE

    Kaas, Raymond

    1980-01-01

    Introduction. On évalue actuellement de 6 à 16 millions de tonnes par an les quantités d'hydrocarbures qui sont rejetées à la mer. Ces pollutions proviennent d'origines différentes : les rejets chroniques liés à l'activité humaine tels les déballastages des pétroliers ou les déversements d'installations côtières de traitement de pétrole ; les rejets chroniques naturels ; les rejets accidentels comme les fuites survenant sur les têtes de puits de forage ou les accidents de pétroliers. Les déve...

  10. Description d'un nouveau brûleur compact. Fonctionnement en régime de gaz prémélangés Description of a New Compact Premixed Gas Burner

    Directory of Open Access Journals (Sweden)

    Minetti R.

    2006-11-01

    Full Text Available On décrit un nouveau brûleur compact à gaz, de haut rendement et d'une puissance variable de 1 à 5 kW. La source de chaleur est une flamme plate d'un prémélange stoechiométrique de gaz naturel et d'air stabilisé sur une grille d'une surface de 100 cm2. Plusieurs grilles en acier inoxydable sont comparées. Elles diffèrent par leur épaisseur, le nombre et la dimension des trous. Un échangeur de chaleur en laiton à circulation d'eau peut être approché jusqu'à 7 mm de la surface du brûleur. La température des gaz frais, le débit et la position de l'échangeur ont été modifiés et les conditions optimales de fonctionnement sont décrites. Les températures à travers les gaz frais, la flamme, les gaz brûlés et les fumées, ont été mesurées. Un modèle simple des échanges de chaleurs est présenté. Il permet une meilleure compréhension des processus de transfert et facilite le choix des conditions opératoires. Dans les meilleures conditions, 93 % du contenu thermique du mélange gazeux est transféré à l'échangeur. Some general characteristics of a compact and efficient gas burner are described (1-5 kW. The heat source is a premixed flat flame stabilized on a 100 cm2 grid fed by a stoechiometric mixture of air and natural gas. Various types of stainless steel grids have been investigated. They differ according to their thickness and to the number and size of the holes. A circulating water heat exchanger made of brass can be approached to the flame as close as 7 mm above the burner surface. The temperature of the inlet gas mixture, the flow rate, and the position of the heat exchanger have been varied. The best working conditions are given as well as the temperature through the fresh gaseous mixture, the temperature profiles of the flame and the temperature of the fumes. From heat transfer calculations a simple model is presented. It gives better insight into the heat transfer processes and facilitates a judicious

  11. Experimental and numerical investigation of flame characteristics during swirl burner operation under conventional and oxy-fuel conditions

    Directory of Open Access Journals (Sweden)

    Jovanović Rastko D.

    2017-01-01

    Full Text Available Oxy-fuel coal combustion, together with carbon capture and storage or utilization, is a set of technologies allowing to burn coal without emitting globe warming CO2. As it is expected that oxy-fuel combustion may be used for a retrofit of existing boilers, development of a novel oxy-burners is very important step. It is expected that these burners will be able to sustain stable flame in oxy-fuel conditions, but also, for start-up and emergency reasons, in conventional, air conditions. The most cost effective way of achieving dual-mode boilers is to introduce dual-mode burners. Numerical simulations allow investigation of new designs and technologies at a relatively low cost, but for the results to be trustworthy they need to be validated. This paper proposes a workflow for design, modeling, and validation of dual-mode burners by combining experimental investigation and numerical simulations. Experiments are performed with semi-industrial scale burners in 0.5 MWt test facility for flame investigation. Novel CFD model based on ANSYS FLUENT solver, with special consideration of coal combustion process, especially regarding devolatilization, ignition, gaseous and surface reactions, NOx formation, and radiation was suggested. The main model feature is its ability to simulate pulverized coal combustion under different combusting atmospheres, and thus is suitable for both air and oxy-fuel combustion simulations. Using the proposed methodology two designs of pulverized coal burners have been investigated both experimentally and numerically giving consistent results. The improved burner design proved to be a more flexible device, achieving stable ignition and combustion during both combustion regimes: conventional in air and oxy-fuel in a mixture of O2 and CO2 (representing dry recycled flue gas with high CO2 content. The proposed framework is expected to be of use for further improvement of multi-mode pulverized fuel swirl burners but can be also used

  12. Les présages expliqués

    CERN Document Server

    Belly

    2015-01-01

    Extrait : ""Les Romains et les Grecs avaient emprunté aux Chaldéens la plupart des arts divinatoires : Ce que disent les caractères de l'Écriture. Ce que disent les lignes du visage. Ce que disent les traits du visage. Ce que disent les cartes, etc.""

  13. Combustion development of an industrial scale burner, with particular reference to coal blends and co-firing coal with natural gas and sawdust

    Energy Technology Data Exchange (ETDEWEB)

    Allen, G. [International Combustion Limited, Derby (United Kingdom). Rolls Royce Industrial Power Group

    1998-12-31

    Described herein are the results of pulverised coal combustion experiments performed on a 35 MWth low NO{sub x} burner installed in International Combustion`s large scale combustion test facility. In-flame and furnace exit combustion/emissions species and temperature measurements were taken during firing trials with: different coal blends; a coal-wood dust fuel blend; coal and natural gas `In-Burner` co-firing. The NO{sub x} and unburned carbon in ash results generated from the coal blend tests were shown to correlate well against fuel ratio. The gas co-firing results confirmed low momentum gas injection along the burner axis as optimum. This reduced NO{sub x} by 16% whilst unburned carbon in ash fell from 3 to 1.5%. Larger NO{sub x} reductions were anticipated by virtue of activating an `In-Burner` gas reburn de-NO{sub x} process. A 1/2th scale isothermal low NO{sub x} burner model was used to characterise pulverized coal particle (PF) dynamics in the near burner region. Laser sheet velocimetry and laser doppler anemometry measurements indicated that the larger PF particles follow a straight trajectory and penetrate the burner internal recirculation zone. Conversely, the smaller PF particles are drawn radially outwards into the shear layer between the burner PA and SA flow streams to initiate combustion. A CFD model of this burner was validated against the experimental data. This exercise highlighted the importance of specifying accurate CFD model inlet boundary conditions, adopting fine grids, and selecting appropriate turbulence models. This mathematical model was subsequently used to derive new flame stabiliser concepts, which were tested on a full size burner. 9 refs., 27 figs., 8 tabs.

  14. Feasibility investigation and combustion enhancement of a new burner functioning with pulverized solid olive waste

    Directory of Open Access Journals (Sweden)

    Bounaouara H., Sautet J.C., Ben Ticha H., Mhimid A.

    2014-01-01

    Full Text Available This article describes an experimental study on solid olive residue (olive cake combustion in form of pulverized jet. This is a contribution to the valorization of olive residue as a source of renewable energy available in the majority of mediterranean countries. A sample of olive cake from Tunisian origin is prepared for the experiment; this sample is crushed, dried and sifted in order to obtain the desired particles form. A new burner made up of a coaxial cylindrical tube is especially designed and fabricated. In order to start the combustion of olive cake and maintain the main flame, two types of pilot flame were used: a central premixed flame of methane/oxygen and an annular diffusion flame of methane. This paper shows the conditions for an efficient olive cake burner operation in free air. The effects of particle size and pilot flame position have been discussed. The olive cake combustion is possible only with particles at a size below 200 μm. Moreover, the combustion maintained by the annular pilot flame ensures better burning conditions than the central pilot flame. Finally, the inserted preheating system has improved the olive cake combustion.

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

    KAUST Repository

    Tran, Vu Manh

    2016-09-11

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

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

    KAUST Repository

    Yamamoto, Kazuhiro

    2015-05-01

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

  17. A New Method to Measure Temperature and Burner Pattern Factor Sensing for Active Engine Control

    Science.gov (United States)

    Ng, Daniel

    1999-01-01

    The determination of the temperatures of extended surfaces which exhibit non-uniform temperature variation is very important for a number of applications including the "Burner Pattern Factor" (BPF) of turbine engines. Exploratory work has shown that use of BPF to control engine functions can result in many benefits, among them reduction in engine weight, reduction in operating cost, increase in engine life, while attaining maximum engine efficiency. Advanced engines are expected to operate at very high temperature to achieve high efficiency. Brief exposure of engine components to higher than design temperatures due to non-uniformity in engine burner pattern can reduce engine life. The engine BPF is a measure of engine temperature uniformity. Attainment of maximum temperature uniformity and high temperatures is key to maximum efficiency and long life. A new approach to determine through the measurement of just one radiation spectrum by a multiwavelength pyrometer is possible. This paper discusses a new temperature sensing approach and its application to determine the BPF.

  18. NON-INTRUSIVE GAS-PHASE THERMOMETRY FOR INDUSTRIAL OXY-FUEL BURNERS

    Directory of Open Access Journals (Sweden)

    J. W. Tröger

    2015-03-01

    Full Text Available The use of oxy-fuel combustion processes is of large interest for several industrial fields applications since it offers the advantages of low NOx emissions in combination with high combustion temperatures even without additional preheating. For optimization of such processеs a detailed understanding based on precise experimental data is necessary. So far there is still a lack of precise experimental data achieved with high spatial and temporal resolution from industrial relevant turbulent oxy-fuel combustion processes. Beside species concentration information the gas phase temperature is of utmost importance for an improved understanding of the basic chemical reactions and the pollutant formation. The coherent anti-Stokes Raman spectroscopy (CARS technique is a very well suited laser based tool for a non-intrusive investigation of such turbulent high temperature combustion processes. In this work we analysed an industrial 400 kW oxy-fuel burner with the help of O2 based vibrational CARS system which is integrated in an industrial relevant test furnace. The burner is fed with pure oxygen and natural gas at an equivalence ratio of =0.9. At one downstream position temporal and spatial resolved temperatures were measured along a 600 mm line. Additional air sucked in from the environment seems to influence the gas phase temperature significantly.

  19. Performance Evaluation of Palm Oil-Based Biodiesel Combustion in an Oil Burner

    Directory of Open Access Journals (Sweden)

    Abdolsaeid Ganjehkaviri

    2016-02-01

    Full Text Available This paper presents an experimental investigation of the combustion characteristics of palm methyl ester (PME, also known as palm oil-based biodiesel, in an oil burner system. The performance of conventional diesel fuel (CDF and various percentages of diesel blended with palm oil-based biodiesel is also studied to evaluate their performance. The performance of the various fuels is evaluated based on the temperature profile of the combustor’s wall and emissions, such as nitrogen oxides (NOx and carbon monoxide (CO. The combustion experiments were conducted using three different oil burner nozzles (1.25, 1.50 and 1.75 USgal/h under lean (equivalence ratio (Φ = 0.8, stoichiometric (Φ = 1 and rich fuel (Φ = 1.2 ratio conditions. The results show that the rate of emission formation decreases as the volume percent of palm biodiesel in a blend increases. PME combustion tests present a lower temperature inside the chamber compared to CDF combustion. High rates of NOx formation occur under lean mixture conditions with the presence of high nitrogen and sufficient temperature, whereas high CO occurs for rich mixtures with low oxygen presence.

  20. The oil pore burner for household furnaces; Der Oelporenbrenner fuer die Haushaltsfeuerung

    Energy Technology Data Exchange (ETDEWEB)

    Heidermann, T.; Keppler, M.; Rutsche, A.; Hatzfeld, O.; Koehne, H.; Lucka, K.; Rudolphi, R.; Trimis, D.; Durst, F.

    1999-07-01

    While heating of modern buildings requires less and less energy, sufficient heat is still required for water heating. There is a trend towards compact, low-emission and high-efficiency systems. The oil pore burner developed at LSTM Erlangen is a promising technology, which combines the cold flame evaporation concept of EST of RWTH Aachen with the pore burner technology. The result is a modern system for high-modulating, low-emission and low-noise combustion of heating oil with exhaust condensation. A 10% improvement in furnace efficiency is achieved. [German] Waehrend der Raumwaermebedarf moderner Wohneinheiten stetig sinkt, erfordert die Warmwasserbereitung nach wie vor die Bereitstellung ausreichend grosser Waermeleistungen. Aus diesem Grund geht der Trend bei modernen Oelfeuerungsanlagen im Haushaltsbereich in zu kompakten, emissionsarmen Einheiten mit Brennwertnutzung. Einen Druchbruch verspricht der Oelporenbrenner. Der Porenbrennertechnik wurde am LSTM Erlangen entwickelt. Der Oelporenbrenner vereinigt das am EST der RWTH Aachen entwickelte Verdampfungskonzept unter Nutzung der Kalten Flammen mit der Porenbrennertechnik zu einem neuartigen Heizgeraetekonzept, das die hochmodulierbare, schadstoff- und geraeuscharme Verbrennung von Heizoel mit Brennwertnutzung ermoeglicht. Dadurch wird eine Verbesserung des Feuerungwirkungsgrades bis zu 10% erreicht. (orig.)

  1. The Study of Numerical Simulation of Oxygen-‎enriched Burner System

    Directory of Open Access Journals (Sweden)

    Yuesheng Fan

    2010-12-01

    Full Text Available In order to reduce overall fuel consumption, or partially substitute a “valuable” fuel with a ‎poor one, in electric power plant boilers, oxygen enrichment of combustion air can be very ‎effective. The paper proposes an oxygen-enriched ignition system which based on the ‎existing pulverized coal fired boiler ignition devices. Small coal particle is suitable for this ‎system. The new burner includes inside, outside and middle casings. And it transfer heat in ‎two ways of downstream and upstream. The burner has authorized a patent in China. A ‎numerical simulation theory were used to analysis it. The results indicate that: it can ‎increase the maximum burning velocity ‎ ‎ and the average burning ‎velocity ‎, and decrease ignition temperature Ti and burnout temperature Tb of ‎pulverized coal. In addition, the pulverized coal fired boilers are easier to be ignited and the ‎comprehensive combustibility index S is improved. At the same time, it demonstrates that it ‎is an effective way to warm-up the pulverized coal in ignition of the boiler in the power ‎plant.‎

  2. Modeling Population Exposures to Pollutants Emitted from Natural Gas Cooking Burners

    Energy Technology Data Exchange (ETDEWEB)

    Lobscheid, Agnes; Singer, Brett C.; Klepeis, Neil E.

    2011-06-01

    We developed a physics-based data-supported model to investigate indoor pollutant exposure distributions resulting from use of natural gas cooking appliances across households in California. The model was applied to calculate time-resolved indoor concentrations of CO, NO2 and formaldehyde resulting from cooking burners and entry with outdoor air. Exposure metrics include 1-week average concentrations and frequency of exceeding ambient air quality standards. We present model results for Southern California (SoCal) using two air-exchange scenarios in winter: (1) infiltration-only, and (2) air exchange rate (AER) sampled from lognormal distributions derived from measurements. In roughly 40percent of homes in the SoCal cohort (N=6634) the 1-hour USEPA NO2 standard (190 ?g/m3) was exceeded at least once. The frequency of exceeding this standard was largely independent of AER assumption, and related primarily to building volume, emission rate and amount of burner use. As expected, AER had a more substantial impact on one-week average concentrations.

  3. Dynamic rod worth simulation study for a sodium-cooled TRU burner

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Ji; Ha, Pham Nhu Viet, E-mail: phamha@kaeri.re.kr; Lee, Min Jae; Kang, Chang Mu

    2015-12-15

    Highlights: • Dynamic rod worth calculation methodology for a sodium-cooled TRU burner was developed. • The spatial weighting functions were relatively insensitive to control rods position. • The simulated pseudo detector response agreed well with the calculated core power. • The simulated dynamic rod worths compared well against the simulated static values. • Impact of individual detector on the simulated dynamic worth was evaluated. - Abstract: This paper presents a preliminary dynamic rod worth simulation study for a TRU burner core mockup of the PGSFR (Korean Prototype Gen-IV Sodium-cooled Fast Reactor) named BFS-76-1A so as to establish a calculation methodology for evaluating the rod worth of the PGSFR. The simulation method was mainly based on a three-dimensional multi-group nodal diffusion transient code for fast reactors in which the rod drop simulation for the BFS-76-1A was performed and all the fuel assemblies were taken into account for the detector response calculation. Then the dynamic rod worths were inferred from the simulated detector responses using an inverse point kinetics model and compared against the simulated static worths. The results show good agreement between the simulated pseudo detector response and the calculated core power as well as between the simulated dynamic and static rod worths, and thus indicate that the dynamic rod worth simulation method developed in this work can be applied to the rod worth estimation and validation for the PGSFR.

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

    Directory of Open Access Journals (Sweden)

    Redko A.

    2017-08-01

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

  5. Optimum feeding rate of solid hazardous waste in a cement kiln burner

    Directory of Open Access Journals (Sweden)

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

    2013-01-01

    Full Text Available Solid hazardous waste mixed with wood chips (SHW is a partly CO2 neutral fuel, and hence is a good candidate for substituting fossil fuels like pulverized coal in rotary kiln burners used in cement kiln systems. SHW is used in several cement plants, but the optimum substitution rate has apparently not yet been fully investigated. The present study aims to find the maximum possible replacement of coal by SHW, without negatively affecting the product quality, emissions and overall operation of the process. A full-scale experiment was carried out in the rotary kiln burner of a cement plant by varying the SHW substitution rate from 0 to 3 t/hr. Clinker quality, emissions and other relevant operational data from the experiment were analysed using fuel characteristics of coal and SHW. The results revealed that SHW could safely replace around 20% of the primary coal energy without giving negative effects. The limiting factor is the free lime content of the clinker. Results from the present study were also compared with results from a previous test using meat and bone meal.

  6. Optimum feeding rate of solid hazardous waste in a cement kiln burner

    Energy Technology Data Exchange (ETDEWEB)

    Ariyaratne, W.K. Hiromi; Melaaen, Morten C.; Tokheim, Lars-Andre [Telemark University College, Faculty of Technology, Kjoelnes Ring 56, P.O. Box 203, N-3901, Porsgrunn (Norway)

    2013-07-01

    Solid hazardous waste mixed with wood chips (SHW) is a partly CO2 neutral fuel, and hence is a good candidate for substituting fossil fuels like pulverized coal in rotary kiln burners used in cement kiln systems. SHW is used in several cement plants, but the optimum substitution rate has apparently not yet been fully investigated. The present study aims to find the maximum possible replacement of coal by SHW, without negatively affecting the product quality, emissions and overall operation of the process. A full-scale experiment was carried out in the rotary kiln burner of a cement plant by varying the SHW substitution rate from 0 to 3 t/hr. Clinker quality, emissions and other relevant operational data from the experiment were analysed using fuel characteristics of coal and SHW. The results revealed that SHW could safely replace around 20% of the primary coal energy without giving negative effects. The limiting factor is the free lime content of the clinker. Results from the present study were also compared with results from a previous test using meat and bone meal.

  7. Les discours politiques. Approches interactionnistes et multimodales

    OpenAIRE

    Chanay, Hugues de Constantin de; Turbide, Olivier

    2011-01-01

    Envisager les discours politiques dans une perspective interactionniste, c’est considérer que la nature politique d’un discours s’établit en fonction de la relation instaurée entre les acteurs et auteurs de ces discours et les différentes catégories de récepteurs. Comme le rappelle Charaudeau (2005, p. 30), ce n’est pas le locuteur qui fait qu’un discours est politique, ni le contenu de son discours, ni les lieux de son expression ou les types d’activités, mais c’est la situation d’interactio...

  8. Retour sur les images d’organisations

    OpenAIRE

    Audigier, Nathalie; Boutin, Éric; Bryon-Portet, Céline; Buisson, Lysiane; Cousineau, Marie-Marthe; Cousserand, Isabelle; Dilliere-Brooks, Stéphanie; Hamel, Sylvie; Hardy, Mylène; Heller, Thomas; Laborde, Aurélie; Lagacé, Martine; Lenay Blason, Alexandra; Le Moënne, Christian; Liu, Pei

    2011-01-01

    Ce numéro 34 de Communication & Organisation est consacré aux approches communicationnelles de l’image des organisations. Les contributions portent sur des aspects théoriques de définition de l’image, sur son application aux organisations, sur des aspects plus méthodologiques, et enfin sur les enjeux critiques qui entourent les pratiques organisationnelles centrées sur l’image. Depuis les années 1970, ce sont surtout les sciences de gestion et la littérature managériale qui ont produit plusie...

  9. Note sur les sur les droits de diffusion des images

    Directory of Open Access Journals (Sweden)

    André Gunthert

    2009-12-01

    Full Text Available Selon l’article L 122-5 du Code de la propriété intellectuelle : « Lorsque l’oeuvre a été divulguée, l’auteur ne peut interdire : (... les analyses et courtes citations justifiées par le caractère critique, polémique, pédagogique, scientifique ou d’information de l’oeuvre à laquelle elles sont incorporées. » La jurisprudence reconnaît aux photogrammes ou vidéogrammes de films la qualité d’extrait bref, constitutif de l’exception de citation. Dans les conditions énoncées par la loi, la public...

  10. Hybrid LES – Review and assessment

    Indian Academy of Sciences (India)

    S Vengadesan; P Nithiarasu

    2007-10-01

    In the late eighties and up to the beginning of nineties computation of turbulent flows is mostly dominated by RANS (Reynolds Averaged Navier–Stokes Simulation) type modelling. During the last few years URANS (Unsteady RANS) and LES (Large Eddy Simulation) type of approaches have been attempted with some success. Yet, there have been many difficulties when LES is applied to practical engineering problems and to high Reynolds number flows as energy dissipating eddies become really small and mesh resolution required for a reasonably resolved LES approaches that of DNS (Direct Numerical Simulation). An alternative solution suggested was to combine RANS and LES, which in general referred to as Hybrid LES. There have been many proposals for combining RANS and LES in different ways. In this article, some of the issues involved in performing hybrid LES reported in the recent literature is briefly reviewed.

  11. Les bienfaits de la mondialisation

    Directory of Open Access Journals (Sweden)

    Denise Pumain

    2013-05-01

    Full Text Available Du pays qui impose un système d’échanges fondé sur l’hypothèse de l’efficacité des marchés, vient enfin une proposition de régulation des excès de l’évasion fiscale, que des officines spécialisées ont euphémisée en « optimisation ». La mesure suffira-t-elle à décourager les propositions alléchantes des paradis fiscaux et à rééquilibrer les forces entre le pouvoir des Etats et la finance spéculative ? La violence de la crise engendrée par ces excès depuis plus de cinq années, dont tant de pers...

  12. Les ennemis d'Internet

    OpenAIRE

    2015-01-01

    À l’occasion de la journée mondiale contre la cybercensure, Reporters sans frontières propose dans un second rapport annuel une cartographie globale et actualisée du phénomène, géopolitique particulière distinguant les pays « ennemis de l’Internet » de ceux « mis sous surveillance ». La liste des ennemis s’est allongée : le Bélarus et Bahrain, placés l’an passé sous surveillance, figurent désormais parmi les régimes autoritaires comme l’Arabie Saoudite, la Chine, Cuba et de façon extrême en S...

  13. Burner (Stinger)

    Science.gov (United States)

    ... Football Sports and Exercise Safety Dealing With Sports Injuries Sports Center Magnetic Resonance Imaging (MRI) Contact Us Print Resources Send to a friend Permissions Guidelines ... Veer, Science Photo Library, Science Source Images, Shutterstock, and Clipart.com

  14. SUSY Les Houches Accord 2

    Energy Technology Data Exchange (ETDEWEB)

    Allanach, B.; Balazs, C.; Belanger, G.; Bernhardt, M.; Boudjema, F.; Choudhury, D.; Desch, K.; Ellwanger, U.; Gambino, P.; Godbole, R.; Goto, T.; Guasch, J.; Guchait, M.; Hahn, T.; Heinemeyer, S.; Hugonie, C.; Hurth, T.; Kraml, S.; Kreiss, S.; Lykken, J.; Moortgat, F.; /Cambridge U., DAMTP /Monash U. /Annecy, LAPTH /Bonn U. /Harish-Chandra Res. Inst. /Orsay, LPT /Turin U. /INFN, Turin /Bangalore, Indian Inst. Sci. /KEK, Tsukuba /Barcelona U. /Tata Inst. /Munich, Max Planck Inst. /Cantabria Inst. of Phys. /Montpellier U. /CERN /SLAC /Edinburgh U. /Fermilab /Zurich, ETH /Southampton U.

    2007-11-08

    The Supersymmetry Les Houches Accord (SLHA) provides a universal set of conventions for conveying spectral and decay information for supersymmetry analysis problems in high energy physics. Here, we propose extensions of the conventions of the first SLHA to include various generalizations: the minimal supersymmetric standard model with violation of CP, R-parity, and flavor, as well as the simplest next-to-minimal model.

  15. SUSY Les Houches Accord 2

    Energy Technology Data Exchange (ETDEWEB)

    Allanach, B.; Balazs, C.; Belanger, G.; Bernhardt, M.; Boudjema, F.; Choudhury, D.; Desch, K.; Ellwanger, U.; Gambino, P.; Godbole, R.; Goto, T.; /Cambridge U., DAMTP /Monash U. /Annecy, LAPTH /Bonn U. /Harish-Chandra Res. Inst. /Orsay, LPT /Turin U. /INFN, Turin /Bangalore, Indian Inst. Sci. /KEK, Tsukuba /Barcelona U.

    2007-11-08

    The Supersymmetry Les Houches Accord (SLHA) [1] provides a universal set of conventions for conveying spectral and decay information for supersymmetry analysis problems in high energy physics. Here, we propose extensions of the conventions of the first SLHA to include various generalizations: the minimal supersymmetric standard model with violation of CP, R-parity, and flavor, as well as the simplest next-to-minimal model.

  16. La Tentation et les savoirs

    Directory of Open Access Journals (Sweden)

    Gisèle Séginger

    2009-01-01

    Full Text Available Malgré son inactualité apparente, La Tentation de Saint Antoine se rattache à une série de savoirs, de recherches historiques, d’interrogations qui caractérisent son époque et définissent une configuration épistémologique. Les savoirs sont impliqués à deux niveaux : dans l’organisation de la poétique de l’œuvre, dans les représentations de l’œuvre. Flaubert utilise des savoirs historiques, anthropologiques et psychiatriques qui légitiment l’organisation du texte et les déconstruit en même temps. Il invente une nouvelle forme de grotesque – le grotesque des idées – et met en abyme un questionnement sur les savoirs qui évolue de la première Tentation à celle de 1874.Despite its apparent irrelevancy to Flaubert's time, La Tentation de Saint Antoine is linked to a net of knowledge, historical research, questions that characterize a period and define an epistemological configuration. These types of knowledge are at play on two levels: in the organization of the poetics of the work and in its representations. Flaubert uses historical, anthropological and psychiatric knowledge which legitimates the organization of the text while at the same time he deconstructs this body of knowledge. Flaubert invents a new form of grotesque – the grotesque of ideas – and, in a mise-en-abyme from the first Tentation to the 1874 version, he questions these fields of knowledge.

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

    Directory of Open Access Journals (Sweden)

    Amal S. Zakhary

    2014-03-01

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

  18. High Pressure Burner Rig Testing of Advanced Environmental Barrier Coatings for Si3N4 Turbine Components

    Science.gov (United States)

    Zhu, Dongming; Fox, Dennis S.; Pastel, Robert T.

    2007-01-01

    Advanced thermal and environmental barrier coatings are being developed for Si3N4 components for turbine engine propulsion applications. High pressure burner rig testing was used to evaluate the coating system performance and durability. Test results demonstrated the feasibility and durability of the coating component systems under the simulated engine environments.

  19. Making a Low-Cost Soda Can Ethanol Burner for Out-of-Laboratory Flame Test Demonstrations and Experiments

    Science.gov (United States)

    Yu, Henson L. Lee; Domingo, Perfecto N., Jr.; Yanza, Elliard Roswell S.; Guidote, Armando M., Jr.

    2015-01-01

    This article demonstrates how to make a low-cost ethanol burner utilizing soda cans. It burns with a light blue flame suitable for out-of-laboratory flame test demonstrations where interference from a yellow flame needs to be avoided.

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

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Maciejowski, Jan

    2008-01-01

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

  1. Les Rêves chez Marguerite Yourcenar

    Directory of Open Access Journals (Sweden)

    Kyeongmi Kim-Bernard

    2005-04-01

    Full Text Available Marguerite Yourcenar a publié un recueil de récits de rêves intitulé Les Songes et Les Sorts en 1938. La préface de ce texte qui registre une trentaine de récits authentiques rêvés entre 1930 et 1936, donc entre ses 28 et 33 ans, nous intéresse particulièrement par ses profondes réflexions sur la matière du rêve dont les traces se trouvent dans ses écrits, notamment romanesques. Partiellement convaincue par la théorie freudienne, elle marque clairement la différence de sa vision sur ce système d’images qu’elle souhaite ne pas être traité comme le sujet d’une analyse psychanalytique ou psychologique: elle refuse le rôle intégral du rêve qui serait, selon le fondateur de la psychanalyse, la partie submergée du défoulement psychologique, notamment celle de la libido. « Le freudisme a trop cru à l’unité du symbole.

  2. Les découvreurs

    CERN Document Server

    Boorstin, Daniel

    1986-01-01

    Sous une forme vivante, enlevée, très personnelle, Les Découvreurs raconte la plus grande épopée de l'homme : celle de sa quête pour découvrir le monde qui l'entoure. Daniel Boorstin s'écarte volontairement de la traditionnelle et fastidieuse énumération des batailles, des naissances d'empires et des grands règnes : avec lui, l'histoire de notre monde devient une féerie de découvertes et de commencements. En chaque découverte d'importance, que ce soit celle de l'Amérique par Christophe Colomb ou celle de la relativité par Einstein, il voit un épisode d'une biographie. Les héros de la saga qu'il nous raconte sont des hommes dotés d'une insatiable frénésie de connaissance et d'un courage exemplaire pour affronter l'inconnu. Daniel Boorstin nous fait découvrir sous un jour nouveau des noms familiers : Hérodote, Ptolémée, Marco Polo, Copernic, Newton, Marx, Freud, et ressuscite également quelques figures remarquables oubliées de l'histoire. Pour quelles raisons les Chinois n'ont-ils pas...

  3. Les leaders d'opinion sur les réseaux socionumériques

    OpenAIRE

    Camille Alloing; Marie Haikel-Elsabeh

    2012-01-01

    L'une des problématiques des entreprises investissant dans les campagnes marketing sur les réseaux sociaux numériques est de déterminer une population cible qui a une capacité de diffusion et de médiatisation identifiable. Le concept de leader d'opinion semble de prime abord répondre aux caractéristiques souhaitées par les entreprises pour des actions marketing sur Internet. Seulement, les leaders d'opinions sont-ils les seuls usagers d'Internet à pouvoir influer sur les cibles de l'entrepris...

  4. Study of the effects of ambient conditions upon the performance of fan powered, infrared, natural gas burners. Quarterly technical progress report, July 1--September 30, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Bai, T.; Yeboah, Y.D.; Sampath, R.

    1995-10-01

    The objective of this investigation is to characterize the operation of fan powered infrared burner (PIR) at various gas compositions and ambient conditions and develop design guidelines for appliances in containing PIR burners for satisfactory performance. During this period, experimental setup with optical and electronic instrumentation that is necessary for measuring the radiant heat output and the emission gas output of the burner has been established. The radiation measurement instrument, an FTIR, has been purchased and installed in the porous burner experimental system. The radiation measurement capability of the FTIR was tested and found to be satisfactory. A standard blackbody source, made by Graseby Infrared, was employed to calibrate the FTIR. A collection duct for emission gas measurement was fabricated and connected to the existing Horiba gas analyzer. Test runs are being conducted for flue gas analysis. A number of published research papers on modeling of porous burners were reviewed. The physical mechanism and theoretical analysis of the combustion process of the PIR burner was formulated. The numerical modeling, and implementation of a PIR burner code at CAU`s computing facility is in progress.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-09-30

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

  6. Les torsions sur testicules cryptorchides

    Science.gov (United States)

    Gharbi, Mohamed; Amri, Najmeddine; Chambeh, Wahib; Braiek, Salem; Kamel, Rafik El

    2010-01-01

    Résumé But : La cryptorchidie est une pathologie assez fréquente en urologie. Elle est associée à un risque élevé d’infertilité et de dégénérescence. Elle semble aussi être associée à un risque important de torsion. Cette entité est très peu abordée dans la littérature. Nous rapportons tous les cas de torsion sur testicule cryptorchide observés à notre service dans le but de mieux caractériser cette pathologie et de réduire ainsi le taux d’orchidectomies. Méthodologie : Il s’agit d’une étude rétrospective portant sur tous les cas de torsion sur testicule cryptorchide opérés dans notre service d’urologie entre 1999 et 2007. Les patients ont fait l’objet d’une description basée sur le résumé de leurs observations. Résultats : Les patients étaient âgés de 7 mois à 39 ans. La torsion touchait le testicule droit dans 53 % des cas. Le tableau clinique comportait une douleur au niveau de la région inguinale d’apparition soudaine avec une masse sous-cutanée inflammatoire et douloureuse à ce niveau et surtout un hémiscrotum homolatéral vide. Dans 60 % des cas, le diagnostic était tardif et une orchidectomie a été réalisée. Dans les autre cas, un abaissement du testicule a été réalisé avec orchidopexie controlatéral dans le même temps opératoire. Conclusion : Bien qu’il s’agisse d’une pathologie peu courante, la torsion sur testicule cryptorchide doit être étudiée davantage. Le diagnostic précoce permettra de sauver et d’abaisser le testicule et faciliter ainsi le dépistage d’une éventuelle dégénérescence. PMID:21191497

  7. Communiquer ! les bibliothécaires, les décideurs et les journalistes

    CERN Document Server

    2010-01-01

    L'enjeu de la communication en direction des élus, des décideurs, mais aussi des journalistes, est devenu vital pour les bibliothèques : il s'agit de donner à voir aux tutelles leurs activités, de rendre intelligible leur stratégie de développement, de construire une image institutionnelle forte. De quels moyens dispose la bibliothèque pour faire la preuve du bien-fondé de son existence ? Comment communiquer en direction d'un élu municipal ou régional, d'un responsable politique de la bibliothèque ? Que peut apporter une bonne collaboration avec des journalistes, avec les partenaires naturels ou hiérarchiques au sein de l'université ou de la collectivité territoriale ? Comment utiliser à bon escient les méthodes du lobbying et du marketing, ou l'emploi des réseaux sociaux ? Voilà quelques-unes des questions abordées ici.

  8. "Les actants, les acteurs et les figures”, de A. J. Greimas

    Directory of Open Access Journals (Sweden)

    Baquero Velásquez Julia Marlén

    1991-06-01

    Full Text Available "Les actants, les acteurs et les figures" es un artículo de carácter teórico en el cual Greimas intenta responder los siguientes interrogantes: ¿Qué se entiende por actantes, actores y figuras? ¿Cómo se diferencian unos de otros? ¿, Cómo se relacionan estos tres conceptos? ¿Qué ubicación tiene cada uno en el marco de la teoría semiótica general? No se puede decir, sin embargo, que tal información se pueda obtener en forma precisa a partir de este texto, quizá debido, por un lado, a que el artículo supone el conocimiento de otros textos que especifican parte de los planteamientos del autor, y, por otro, a que Greimas en tal época no había elaborado suficientemente su teoría, sino que se encontraba construyéndola.

  9. Les modèles fractals en finance.

    OpenAIRE

    Idier, J.

    2011-01-01

    Pour rappeler l’apport du mathématicien Benoît Mandelbrot, connu pour la théorie des fractales élaborée dès les années 1960 et décédé le 14 octobre 2010, ce court article présente la pertinence économique de sa théorie pour la modélisation des marchés financiers, des événements extrêmes ou encore des phénomènes de contagion.

  10. Discussion on Combustion Gas Burner and its Application in Industry%浅论燃气燃烧器及其在工业中的应用

    Institute of Scientific and Technical Information of China (English)

    刘彬; 陆羽

    2013-01-01

    简要介绍了目前工业生产中常用的燃气燃烧器的种类,各种燃烧器的基本原理、特点,并根据各种燃烧器的特点分别介绍了其在工业中的适用场合。%The paper briefly introduces types of combustion gas burner used in existing industrial production, basic principle and characteristics of all burners, meanwhile, the paper respectively introduces the applicable occasions in industry according to characteristic of the burners.

  11. Experiments on the TECFLAM standard burner. Final colloquium; Experimente am TECFLAM Standard-Brenner. Abschlusskolloquium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    This year's annual seminar had two main subjects: First, the final colloquium of the CRAY-TECFLAM project in which an industrial code for simulation of combustion processes in furnaces and gas turbines was developed in cooperation with the relevant industry, and secondly, investigations on a TECFLAM standard burner which served to establish a reliable set of state variables by different methods that were applied simultaneously, as well as the validation of the mathematical models. [German] Das alljaehrliche oeffentliche Seminar stand in diesem Jahr unter zwei zentralen Themen: zum einen das Abschlusskolloquium des CRAY-TECFLAM-Projekts, in dem ein Industriecode zur Simulation der Verbrennungsvorgaenge in Feuerungen und Gasturbinen - unter Beteiligung der relevanten Industrie - entwickelt wurde, zum anderen die Untersuchungen am TECFLAM Standardbrenner, mit denen ein verlaesslicher Satz von Zustandsgroessen mit unterschiedlichen, aber simultan angewandten Messmethoden ermittelt wird und die mathematischen Modelle validiert werden. (orig.)

  12. On the instability of a modified cup-burner flame in the infrared spectral region

    Directory of Open Access Journals (Sweden)

    Petr Bitala

    2016-03-01

    Full Text Available This study describes the modification of a standardised cup-burner apparatus. The replacement of the original glass chimney is performed by shielding a nitrogen co-flow enabled measurement at a wavelength of 3.9 μm. This modification, together with a special arrangement of the measuring system (spectral filtering, data acquisition and post-processing, permitted the observation of various types of hydrodynamic instabilities, including transition states. The advantages of our arrangement are demonstrated with an ethylene non-premixed flame with high sooting tendency. Two known modes of hydrodynamic instability (varicose and sinuous that occur in buoyant flames were studied and described quantitatively. Based on the intensity of the infrared emissions, we identified and qualitatively described the modes of periodic hydrodynamic instability that are accompanied by flame tip opening, which has not been observed for this type of flame.

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

    Directory of Open Access Journals (Sweden)

    Luciano Fanton

    2012-01-01

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

  14. Assessment of Startup Fuel Options for the GNEP Advanced Burner Reactor (ABR)

    Energy Technology Data Exchange (ETDEWEB)

    Jon Carmack (062056); Kemal O. Pasamehmetoglu (103171); David Alberstein

    2008-02-01

    The Global Nuclear Energy Program (GNEP) includes a program element for the development and construction of an advanced sodium cooled fast reactor to demonstrate the burning (transmutation) of significant quantities of minor actinides obtained from a separations process and fabricated into a transuranic bearing fuel assembly. To demonstrate and qualify transuranic (TRU) fuel in a fast reactor, an Advanced Burner Reactor (ABR) prototype is needed. The ABR would necessarily be started up using conventional metal alloy or oxide (U or U, Pu) fuel. Startup fuel is needed for the ABR for the first 2 to 4 core loads of fuel in the ABR. Following start up, a series of advanced TRU bearing fuel assemblies will be irradiated in qualification lead test assemblies in the ABR. There are multiple options for this startup fuel. This report provides a description of the possible startup fuel options as well as possible fabrication alternatives available to the program in the current domestic and international facilities and infrastructure.

  15. Performance (Off-Design) Cycle Analysis for a Turbofan Engine With Interstage Turbine Burner

    Science.gov (United States)

    Liew, K. H.; Urip, E.; Yang, S. L.; Mattingly, J. D.; Marek, C. J.

    2005-01-01

    This report presents the performance of a steady-state, dual-spool, separate-exhaust turbofan engine, with an interstage turbine burner (ITB) serving as a secondary combustor. The ITB, which is located in the transition duct between the high- and the low-pressure turbines, is a relatively new concept for increasing specific thrust and lowering pollutant emissions in modern jet-engine propulsion. A detailed off-design performance analysis of ITB engines is written in Microsoft(Registered Trademark) Excel (Redmond, Washington) macrocode with Visual Basic Application to calculate engine performances over the entire operating envelope. Several design-point engine cases are pre-selected using a parametric cycle-analysis code developed previously in Microsoft(Registered Trademark) Excel, for off-design analysis. The off-design code calculates engine performances (i.e. thrust and thrust-specific-fuel-consumption) at various flight conditions and throttle settings.

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

    Directory of Open Access Journals (Sweden)

    Riahi Zouhair

    2013-01-01

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

  17. Nuclear data uncertainty analysis on a minor actinide burner for transmuting spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hangbok

    1998-08-01

    A comprehensive sensitivity and uncertainty analysis was performed on a 1200 MWt minor actinides burner designed for a low burnup reactivity swing, negative doppler coefficient, and low sodium void worth. Sensitivities of the performance parameters were generated using depletion perturbation methods for the constrained close fuel cycle of the reactor. The uncertainty analysis was performed using the sensitivity and covariance data taken from ENDF-B/V and other published sources. The uncertainty analysis of a liquid metal reactor for burning minor actinide has shown that uncertainties in the nuclear data of several key minor actinide isotopes can introduce large uncertainties in the predicted performance of the core. The relative uncertainties in the burnup swing, doppler coefficient, and void worth were conservatively estimated to be 180 %, 97 %, and 46 %, respectively. An analysis was performed to prioritize the minor actinide reactions for reducing the uncertainties. (author). 41 refs., 17 tabs., 1 fig.

  18. Studi Eksperimen Distribusi Temperatur Nyala Api Kompor Bioetanol Tipe Side Burner dengan Variasi Diameter Firewall

    Directory of Open Access Journals (Sweden)

    R.R. Vienna Sona Saputri Soetadi

    2012-09-01

    Full Text Available Untuk mendapatkan kompor bioetanol efisiensi thermal maksimal diperlukan penelitian komprehensif. Salah satunya adalah penelitian terhadap posisi peletakkan beban pada kompor bioetanol kompak. Pengujian dilakukan pada kompor uji bioetanol dengan kadar 99%, yaitu kompor bioetanol tipe side burner dengan firewall 2.5 inci dan firewall 3 inci. Pengukuran temperatur api dengan 13 thermocouple K dengan pengukuran searah api keatas setiap 5 mm-an. Kemudian, water boiling test dilakukan untuk mendapatkan daya dan beban dan dilanjutkan mengukur waktu pendidihan air. Hasil penelitian ini menunjukkan gambaran total distribusi temperatur nyala api difusi. Hasil menunjukkan untuk kompor 2.5 inci dengan daya 1.6 kW mempunyai temperatur 542 ºC dengan jarak ketinggian 5 mm dari rim kompor sedangkan kompor 3 inci menghasilkan daya 2.38 kW dengan temperatur 516 ºC.

  19. Pollutant exposures from unvented gas cooking burners: A Simulation-based Assessment for Southern California

    Energy Technology Data Exchange (ETDEWEB)

    Logue, Jennifer M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Indoor Environment Group and Residential Building Systems Group; Klepeis, Neil E. [Stanford Univ., CA (United States). Dept. of Civil and Environmental Engineering; San Diego Univ., CA (United States). Center for Behavioral Epidemiology and Community Health; Lobscheid, Agnes B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Indoor Environment Group; Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Indoor Environment Group and Residential Building Systems Group

    2014-01-01

    Residential natural gas cooking burners (NGCBs) can emit substantial quantities of pollutants, and they are typically used without venting range hoods. In this study, LBNL researchers quantified pollutant concentrations and occupant exposures resulting from NGCB use in California homes.The simulation model estimated that—in homes using NGCBs without coincident use of venting range hoods -- 62%, 9%, and 53% of occupants are routinely exposed to NO2, CO, and HCHO levels that exceed acute health-based standards and guidelines. NGCB use increased the sample median of the highest simulated 1-hr indoor concentrations by 100, 3,000, and 20 ppb for NO2, CO, and HCHO, respectively. The study recommends that reducing pollutant exposures from NGCBs should be a public health priority. Simulation results suggest that regular use of even moderately effective venting range hoods would dramatically reduce the percentage of homes in which concentrations exceed health-based standards.

  20. SIMULATION MODELING OF AN ENHANCED LOW-EMISSION SWIRL-CASCADE BURNER

    Energy Technology Data Exchange (ETDEWEB)

    Ala Qubbaj

    2003-10-01

    The numerical computations were conducted using the CFD-CHEMKIN computational program. A cell-centered control volume approach was used, in which the discretized equations or the finite difference equations (FDE) were formulated by evaluating and integrating fluxes across the faces of control volumes in order to satisfy the continuity, momentum, energy and mixture fractions conservation equations. The first order upwind scheme and the well-known SIMPLEC algorithm were used. The standard k-{var_epsilon} model was used to close the set of equations. The thermal and composition fields in the baseline, cascade, swirl, and swirl-cascade burners were simulated. The temperature and CO{sub 2} concentration fields were just computed and the observations are reported. The analysis of these results is currently underway.

  1. Investigation of the Effect of Pilot Burner on Lean Blow Out Performance of A Staged Injector

    Institute of Scientific and Technical Information of China (English)

    YANG Jinhu; ZHANG Kaiyu; LIU Cunxi; RUAN Changlong; LIU Fuqiang; XU Gang

    2014-01-01

    The staged injector has exhibited great potential to achieve low emissions and is becoming the preferable choice of many civil airplanes.Moreover,it is promising to employ this injector design in military engine,which requires most of the combustion air enters the combustor through injector to reduce smoke emission.However,lean staged injector is prone to combustion instability and extinction in low load operation,so techniques for broadening its stable operation ranges are crucial for its application in real engine.In this work,the LBO performance of a staged injector is assessed and analyzed on a single sector test section.The experiment was done in atmospheric environment with optical access.Kerosene-PLIF technique was used to visualize the spray distribution and common camera was used to record the flame patterns.Emphasis is put on the influence of pilot burner on LBO performance.The fuel to air ratios at LBO of six injectors with different pilot swirler vane angle were evaluated and the obtained LBO data was converted into data at idle condition.Results show that the increase of pilot swirler vane angle could promote the air assisted atomization,which in turn improves the LBO performance slightly.Flame patterns typical in the process of LBO are analyzed and attempts are made to find out the main factors which govern the extinction process with the assistance of spray distribution and numerical flow field results.It can be learned that the flame patterns are mainly influenced by structure of the flow field just behind the pilot burner when the fuel mass flow rate is high; with the reduction of fuel,atomization quality become more and more important and is the main contributing factor of LBO.In the end of the paper,conclusions are drawn and suggestions are made for the optimization of the present staged injector.

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

    Directory of Open Access Journals (Sweden)

    Marzena Gibczyńska

    2016-12-01

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

  3. Methane combustion in catalytic premixed burners; Combustione del metano in bruciatori catalitici premiscelati

    Energy Technology Data Exchange (ETDEWEB)

    Cerri, I.; Saracco, G.; Specchia, V. [Turin Politecnico, Turin (Italy). Dipt. di scienza dei materiali ed ingegneria chimica

    1999-06-01

    Catalytic premixed burners for domestic boiler applications were developed with the aim of achieving a power modularity from 10 to 100% and pollutant emissions limited to NO{sub x} (<)75 ppmv, CO(<)100 ppmv, HC(<)10 ppmv. The catalyst played a strategic role in reducing the CO and HC emissions, particularly when operating at superficial heat power lower than 800 kw/m{sup 2}, where the combustion took place entirely inside the burner heating it to incandescence and allowing a decrease in the flame temperature and NO{sub x} emissions. Such results were confirmed through further tests carried out in a commercial industrial-scale boiler equipped with the conical panels. All the results, by varying the excess air and the heat power employed, are presented and discussed. [Italian] Sono stati sviluppati bruciatori catalitici premiscelati con l'intento di raggiungere una modulazione della potenza termica dal 10 al 100% con una limitata generazione di emissioni inquinanti. Il catalizzatore ha giocato un ruolo strategico nel ridurre le missioni di CO e HC, specialmente per carichi termici inferiori a 800 kw/m{sup {sup }}, valori per i quali la combustione si realizza all'interno del apnnello che, raggiungendo le condizioni radianti, permette la riduzione della temperatura di fiamma e quindi dei livelli di NO{sub x}. Tali risultati sono stati poi confermati da ulteriori prove realizzate in una caldaia commerciale di scala industriale su due pannelli conici. Tutti i risultati, al variare dell'eccesso d'aria e della potenza termica impiegata, vengono presentati e discussi.

  4. Les AOC dans la mondialisation

    Directory of Open Access Journals (Sweden)

    Jean-Claude Hinnewinkel

    2004-12-01

    Full Text Available Fruit du conflit plusieurs fois séculaire entre les producteurs et le négoce, le terroir vitivinicole est né de phénomènes de « distinction » qui en Bordelais donnent les « crus ». Ces terroirs de production identifiés, il fallut les faire durer, face à conjoncture, face au négoce. Les réussites les plus nettes sont le résultat d’un projet collectif dont l’AOC à la française est l’une des plus spectaculaires. Renforcer le terroir, compris comme un espace de production géré par les producteurs, devient alors une des conditions essentielles de la durabilité du système. L’avenir des AOC réside sans doute dans une meilleure gestion du conflit négoce/production par l’interprofession mais aussi (surtout ! dans un renforcement de la gestion de la production au sein de l’aire de production qu’est le terroir. L’avenir du terroir relève de la gouvernance de cette aire de production avec trois partenaires : la puissance publique (INAO, l’interprofession et le syndicat des producteurs. Se pose dès lors la question du partage des compétences et la durabilité des AOC paraît liée en grande partie à une définition claire du rôle et donc du statut des syndicats de producteurs, à une véritable gouvernance locale, seule capable de donner du sens à l’ancrage géographique des vins dits de « terroir ». Mais alors ne faut-il pas impliquer un troisième partenaire, la société locale toute entière à travers ses représentations démocratique et associative ?Resulting from century-long conflicts between producers and merchants, vineyards have developped out of "distinction" phenomenons which in the Bordeaux region gave birth to "crus" (vintages. Such identified terroirs had to be defended: the French collective AOC (Denomination of Origin project is one of the most spectacular success. The terroir, as production territory organized by producers, is one of the essential conditions for sustainability

  5. Lesão muscular nos atletas

    OpenAIRE

    Barroso,Guilherme Campos; Thiele,Edilson Schwansee

    2011-01-01

    Este artigo tem por objetivo demonstrar a fisiologia, o diagnóstico e o tratamento das lesões musculares com foque nos atletas, suas demandas e expectativas. As lesões musculares estão entre as queixas mais comuns no atendimento ortopédico, ocorrendo tanto em atletas como em não atletas. Estas lesões caracterizam um desafio para os especialistas, haja vista a lenta recuperação que afasta o atleta dos treinamentos e competições, as frequentes sequelas e a recorrência das lesões. A maior parte ...

  6. Espaces de femmes dans les territoires urbains

    OpenAIRE

    Rouag Djenidi, Abla

    2012-01-01

    En Algérie, les espaces féminins étaient essentiellement les espaces domestiques de la maison traditionnelle où la femme régnait sur les activités et le groupe domestique. Les espaces publics urbains étaient des espaces masculins Nous assistons actuellement à une évolution dans la condition de la femme mais également dans sa relation à l’espace urbain qui est de plus en plus investi par la population féminine. L’espace domestique s’ouvre de plus en plus à l’homme, en restant toutefois le terr...

  7. Protection contre les radiations recommandations

    CERN Document Server

    Claude, A; Kipfer, P; Bacq, Z

    Considérations générales ; mesures de sécurité vis-à-vis des sources de rayonnement externes ; mesures de sécurité vis-à-vis des radioisotopes ; étude spéciale de la protection dans quelques cas particuliers ; mesures de sécurité vis-à-vis des neutrons ; mesures de protection pour les appareils de supervoltage ; appareils physiques de mesure et de contrôle pour la protection.

  8. Les PME en forte croissance.

    OpenAIRE

    Brun, M; F. Chai

    2012-01-01

    Les PME indépendantes en forte croissance dynamisent le tissu économique français : elles créent de nombreux emplois, contribuent significativement à l’innovation et sont particulièrement rentables lorsqu’elles parviennent à émerger. Leur développement rapide exige un mode de financement adapté : une fois parvenues à maturité, ces entreprises augmentent leur ressources propres afin d’équilibrer leur bilan, ouvrant leur capital à des investisseurs privés, particuliers ou entreprises....

  9. Les esclaves du commandant Quiquandon

    OpenAIRE

    Tymowski, Michal

    2003-01-01

    Le 10 janvier 1895, Albert Grodet, gouverneur général du Soudan français, adressa au ministère des Colonies une dépêche accusant le commandant Quiquandon, dirigeant de la région Nord-Est (Ségou), d'exploiter illégalement un domaine sur lequel travaillent 140 esclaves. À partir de ce cas particulier, l'auteur analyse les conflits qui existaient à l'époque entre l'administration civile et un groupe d'officiers soudanais. Il se demande si la possession d'esclaves par des officiers, prenant...

  10. Les écoulements fluviaux

    Directory of Open Access Journals (Sweden)

    Huguette VIVIAN

    1992-06-01

    Full Text Available Cette carte présente une image des principaux fleuves et de leurs affluents, ainsi que la situation des principales stations de mesure et des lames d’eau écoulées. Cette mesure des écoulements fluviaux, effectuée d’abord à l’aide des débits mesurés dans 400 stations hydrométriques choisies parmi les 800 du réseau national, a été éventuellement enrichie par des informations complémentaires.

  11. 多喷嘴对置式水煤浆气化炉内固体颗粒微观特性研究%Microscopic characteristics of solid pa rticle s in op posed multi-burner gasifier

    Institute of Scientific and Technical Information of China (English)

    孙利军; 龚岩; 郭庆华; 于广锁

    2014-01-01

    pore structure increases.The isotherm s of ap rticle samp les aer all type II, and the particle samples consist of continuous and complete system of pores.The hysteresis loops are H3-type, and there are a large amount of fractured pores.BET surface area and pore volume increase with increasing distance from the burner plane, and average pore diameter gradually reduces, and larger changes occur in the vicinity of the burne r plane.The mesopores less than 10 nm vary apparently and increase with increasing distances from the burner plane, while the pores larger than 10 nm are almost unchanged.

  12. Pollutant Emissions and Lean Blowoff Limits of Fuel Flexible Burners Operating on Gaseous Renewable and Fossil Fuels

    Science.gov (United States)

    Colorado, Andres

    This study provides an experimental and numerical examination of pollutant emissions and stability of gaseous fueled reactions stabilized with two premixed-fuel-flexible and ultra-low NOx burner technologies. Both burners feature lean combustion technology to control the formation of nitrogen oxides (NOx). The first fuel--flexible burner is the low-swirl burner (LSB), which features aerodynamic stabilization of the reactions with a divergent flow-field; the second burner is the surface stabilized combustion burner (SSCB), which features the stabilization of the reactions on surface patterns. For combustion applications the most commonly studied species are: NOx, carbon monoxide (CO), and unburned hydrocarbons (UHC). However these are not the only pollutants emitted when burning fossil fuels; other species such as nitrous oxide (N2O), ammonia (NH3) and formaldehyde (CH2O) can be directly emitted from the oxidation reactions. Yet the conditions that favor the emission of these pollutants are not completely understood and require further insight. The results of this dissertation close the gap existing regarding the relations between emission of pollutants species and stability when burning variable gaseous fuels. The results of this study are applicable to current issues such as: 1. Current combustion systems operating at low temperatures to control formation of NOx. 2. Increased use of alternative fuels such as hydrogen, synthetic gas and biogas. 3. Increasing recognition of the need/desire to operate combustion systems in a transient manner to follow load and to offset the intermittency of renewable power. 4. The recent advances in measurement methods allow us to quantify other pollutants, such as N 2O, NH3 and CH2O. Hence in this study, these pollutant species are assessed when burning natural gas (NG) and its binary mixtures with other gaseous fuels such as hydrogen (H2), carbon dioxide (CO2), ethane (C 2H6) and propane (C3H8) at variable operation modes including

  13. Les Plantations D’alignements En Turquie

    Directory of Open Access Journals (Sweden)

    Metin SARIBAŞ

    2008-01-01

    Full Text Available L’état actuel des forets de Turquie est insuffisant pour les besoins en bois. İl est indispensable de chercher denouvelles alternatives pour enrichir les produits du bois en dehors de la source forestière. Les plantationsd’alignements peuvent etre les ressources assez abondantes.Actuellement les pays qui font les plantations d’alignements sont: France, L’İtalie, Belgique, Pays-Bas,L’Allemange, L’Angleterre, Hongrie, Turquie, Grèce; L’Iraq, L’İran, Au Japonais, Aux Etat-Unis, Au Canada,L’Argentine, Bosna -Herzégovinia, L’Avustralie, Bulgaria etc. Selon les etudes de L’İnstitut Turc de RecherchePeuplier à İzmit en Turquie, longueurs des plantations routières sont aux environs de 64000km. D’aprés Hilf(1953 en France %10; en Angletterre %30 de production du bois était à l’origine des plantations routières.Depuis longtemps on discute des inconvénients et des avantages des plantations d’alignements. A parte quelquesrares exceptions, les plantations sont donc devenues pratique, courante, confiées le plus souvent a des servicesadministratifs et lorsqu’elles ne sont pas rendues obligatoires, encoragées tout au moins par subventions, enargents ou en nature et par exemptions d’impots.Les essences utilisées dans les plantations d’alignements sont: Le Platane, L’Orme, Le Peuplier, Le Frene, LeTilleul, L’Erable, Le Sycomore, Le Robinier, L’Acacia, Le Pavia, Le Noyer, Le Carya, Le Chataigner, L’Aulne,Le Bouleau, Le Chene, Le Hetre, Le Paulownia, Aillanthe, L’Alisier, Le Charme, Le Murrier etc. Dans notrearticle on porrrait étudier le potentiel prochain en détail les plantations d’alignements actuelle et dans l’avenir.

  14. Low NO{sub x}/SO{sub x} Burner retrofit for utility cyclone boilers. Quarterly technical progress report, July--September 1991

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-31

    Work on process design and LNS Burner design was deferred during this period, pending a reassessment of the project by TransAlta prior to commencement of Budget Period II, and only limited Balance of Plant engineering work was done.

  15. Enhancing the operational dependability of oil and gas burners: radial blowers with compression in two stages; Zur Erhoehung der Betriebssicherheit von Oel- und Gasbrennern: Radialgeblaese mit zweistufiger Verdichtung

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, H. [Produktmanagement Anwendungstechnik, Oertli-Rohleder Waermetechnik GmbH, Moeglingen (Germany)

    1999-02-01

    A blower system for oil and gas burners with blowers (Duopress) is described which achieves high blower compression at low rates of air intake. The high starting resistance of burners is thus easily overcome and operational dependability is much enhanced. Moreover, the system permits modular construction of burner blowers. As a consequence, different sizes of burners can be built and their ease of maintenance is enhanced. (orig.) [Deutsch] Es wird ein Geblaesesystem fuer Oel- oder Gasgeblaesebrenner (Duopress) vorgestellt, welches es ermoeglicht, hohe Geblaesepressungen bei niedrigem Luftvolumenstrom zu erreichen. So lassen sich die hohen Anfahrwiderstaende bei den Brennerstarts muehelos ueberwinden, und man kann eine deutlich gesteigerte Betriebssicherheit erreichen. Das vorgestellte System ermoeglicht zudem eine modulare Bauweise der Brennergeblaese. Dadurch koennen auf einfache Art verschiedene Baugroessen eines Brenners realisiert und die Wartungsfreundlichkeit der Brenner gesteigert werden. (orig.)

  16. Les Fleurs bleues (R. Queneau

    Directory of Open Access Journals (Sweden)

    Séverine Manhaval

    1999-09-01

    Full Text Available Les Fleurs bleues, roman paru en 1965, propose un fascinant voyage dans le temps et dans l'espace géographique des langues, une odyssée au cœur de la problématique babélienne dont il se fait le porte-parole. Queneau joue sur les particularités linguistiques, les idiolectes et les syntaxes dans une perspective transhistorique et cosmopolite, créant un nouvel esperanto romanesque : le « néobabélien ». Toutes les langues s'interpénètrent et se correspondent, enrichissent l'écriture de l'œuvre et dévoilent peu a peu ses prolongements à la fois scientifiques et philosophiques. Queneau élabore ainsi son propre système linguistique et littéraire, dans ce laboratoire de l'arche romanesque, où la langue future est en gestation.Reprenant le flambeau de Noé, l'écrivain entraîne ses lecteurs dans une traversée du déluge qui mêle le rêve et la réalité, l'humour et la nostalgie – celle de la langue unique, la virtuosité du style et la rigueur de la composition. Le roman démantèle les frontières historiques et géographiques, faisant ainsi de Noé une nouvelle figure de l'artiste, sauveur et reconstructeur du Verbe, et chantre de l'infinie potentialité du langage. Non sans humour, son esthétique se fonde sur une dialectique de la contrainte et de la liberté, de la destruction et de la reconstruction, soutenue par un style vif et corrosif. Le conteur, le poète et le mathématicien se rejoignent et conjuguent leur sagesse dans ce roman complexe et déroutant, récit à clés d'une expérience linguistique originale et approfondie.The novel Les Fleurs bleues, which was published in 1965, is an invitation to a fascinating journey into the time and space dimensions of languages, an odyssey into the heart of the Babelian problematics which it publicizes. Queneau plays upon linguistic particularities, idiosyncrasies and syntaxes within a historical and cosmopolitan perspective, and creates a new Esperanto for the novel: the

  17. Les horloges d'Einstein

    CERN Document Server

    Galison, P L

    1999-01-01

    Dans la version traditionnelle de l'Histoire de la relativitÂ? restreinte,la reformulation par EINSTEIN de la simultanÂ?itÂ? est vue comme une intervention quasi-philosophique,rendue possible par le fait qu'il ait pris ses distances par rapport Â? la physique de l'Â?poque. D'autre part,l'emploi d'Einstein au Bureau des Brevets entre dans l'histoire comme un travail bassement quotidien, lui permettant une formation technique certes,mais peu pertinente pour son travail sur la relativitÂ?. Le confÂ?rencier montrera que,bien au contraire,le travail d'Einstein sur les brevets l'a placÂ? au beau milieu de trÂ?s riches discussions culturelles et de brevets menant Â? la synchronisation des horloges le long des voies de chemin de fer reliant les villes d'Europe centrale.Une fois que l'on a compris l'histoire des horloges synchronisÂ?es, le travail d'Einstein sur la relativitÂ? en mai 1905 brille d'un feu trÂ?s diffÂ?rent.

  18. Revenir vers les habitants, revenir sur les territoires

    Directory of Open Access Journals (Sweden)

    Élizabeth Auclair

    2011-05-01

    Full Text Available Le développement durable se voulait un projet de civilisation, mais le concept a vite été fragilisé par la suprématie des intérêts économiques, et par l’enfermement dans des préoccupations d’ordre environnemental. Dans la période de crise actuelle, on s’interroge : comment veut-on vivre ? avec quelles valeurs ? dans quelles villes et dans quels territoires? Il s’agit ici de voir comment les arts et la culture peuvent contribuer à cet objectif du « vivre ensemble ». Au-delà de positionnements opportunistes, on observe qu’une meilleure prise en compte de la culture, dans ses différentes acceptions, peut promouvoir des approches transversales, reposant sur les valeurs de solidarité, de respect de la diversité culturelle, de démocratie locale et de citoyenneté, et remettre ainsi les habitants au cœur des politiques et des projets de territoires. La recomposition du paysage culturel que l’on observe en France, notamment autour des agendas 21 de la culture et des nouveaux territoires de l’art, témoigne de la part d’artistes, élus et autres professionnels de la culture d’une volonté de travailler au plus près de la population afin de monter des projets qui remettent la culture au cœur des politiques locales.Sustainable development was supposed to be a “civilization” concept, but the power of the economic interests and the pressure of the environmental issues have fragilized the concept. With the recent world crisis, many questions now arise: we must change our model, but how do we want to live, with which values and indicators, in what kind of towns and territories? In this article we propose to analyse how cultural development can help to reach the aim of “living together”. Indeed, taking into account cultural diversity and initiating local activities enables to develop new kinds of projects with the inhabitants, and to promote essential values such as local democracy, solidarity, tolerance

  19. The use of ceramic gas burner in paper drying. Combustion and paper coating tests - Final report; Paperin kuivatus keraamisella kaasupolttimella; Polttokokeet laboratoriossa sekae paperin paeaellystyskoe - Loppuraportti

    Energy Technology Data Exchange (ETDEWEB)

    Kiiskinen, H.; Edelman, K. [Technical Research Centre of Finland, Jyvaeskylae (Finland). Combustion and Thermal Engineering Lab.

    1992-12-31

    The use of infrared dryers in drying of paper has rapidly increased. Gas fired IR dryers cause lower investment and smaller operational cost than the electric ones. On the other hand, the massive construction of the gas fired IR dryers causes weaker controllability than possible for the electric IR dryers. Ceramic gas burner is intended for combustion of pre-mixed gas-air mixture. The combustion takes place in a thin layer on the surface of the burner. The heat from combustion is transferred to the ceramic material mainly through convection but also through radiation. The heated ceramic surface emits radiation to it`s surroundings, according to the radiation properties of the ceramic material. The measurements carried out reveal that the emissivity and the surface temperature of the ceramic burner are very close to the present gas fired IR dryers. The radiative heat efficiency of the present devices is about 36-40 %. The highest recorded radiative heat efficiency of the ceramic burner was 36 %. The controllability of the ceramic burner is better than the present ones: the burner responds to changes in the fuel flow within 1-2 seconds and the control range is broad, about 150-450 kW/m{sup 2}. The mechanic strength properties of the ceramic burner are rather poor due to porous and lightweight construction. It is possible to increase the strength e.g. through the use of thicker ceramic fibre but this will decrease the controllability of the burner. The ceramic materials - very likely - will be used in infrared dryers as soon as the mechanical strength problems will be resolved

  20. Les effets de la supervision et de la réglementation sur les crises bancaires

    OpenAIRE

    2006-01-01

    Dans ce papier, nous avons analysé les liens possibles entre les indicateurs de supervision, de réglementation et les crises bancaires, nous avons construit alors différents indicateurs de supervision, de réglementation pour 40 pays développés et émergents. Nous avons appliqué un modèle Logit pour déterminer les variables explicatives de supervision et de réglementation qui expliquent le plus les crises bancaires. Nous avons trouvé que lorsque le pouvoir des autorités de supervision est impor...

  1. Esteróles en esponjas marinas

    Directory of Open Access Journals (Sweden)

    Carmenza Duque

    2009-07-01

    Full Text Available Esta revisión bibliográfica comprende la mayona del trabajo publicado hasta el momento sobre esteróles aislados de esponjas marinas. Estos esteróles comprenden compuestos desde Cig hasta C31 con estructuras convencionales y con estructuras novedosas (núcleo y/o cadena lateral no convencional.

  2. Les associations en milieu urbain dakarois z

    African Journals Online (AJOL)

    vue d'atteindre dans les domaines du social, de l'économique, du culturel, etc., des buts .... lorsqu' on sait l'importance de la relation de l' individu au groupe—et elle est vraiment ..... attendus peuvent concerner en droit soit exclusivement les membres, ..... notamment des coopératives (Thabitat et des GIE ayant affaire avec.

  3. Industrial Applications of LES in Mechanical Engineering

    Science.gov (United States)

    2001-08-01

    UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP013624 TITLE: Industrial Applications of LES in Mechanical Engineering DISTRIBUTION...compilation report: ADP013620 thru ADP013707 UNCLASSIFIED INDUSTRIAL APPLICATIONS OF LES IN MECHANICAL ENGINEERING CHISACHI KATO Institute of Industrial...Science University of Tokyo, Tokyo, Japan MASAYUKI KAIHO, AKIRA MANABE Mechanical Engineering Research Laboratory Hitachi LTD., Ibaraki, Japan Abstract

  4. Inquiétudes pour les emplois

    CERN Multimedia

    2002-01-01

    "Le dépassement budgétaire du LHC oblige la direction a réaliser des économies. Selon les syndicats francais et suisses, ces économies entraineraient des suppressions d'emplois, notamment chez les enterprises sous-traitantes du Cern"

  5. 大型硫磺回收装置燃烧器选型研究%STUDY ON THE MODEL SELECTION OF BURNERS IN LARGE SCALE SRU

    Institute of Scientific and Technical Information of China (English)

    徐璟

    2013-01-01

    从工程实例出发,对大型硫磺回收装置两种不同型式的燃烧器预混式和扩散式燃烧器的结构及性能进行了研究与对比,为此类燃烧器的选型提供一些参考.硫磺回收装置专用燃烧器在装置运行中起到核心作用,燃烧器选型时需要全面、系统地考虑工艺要求、操作安全性和设备运行维护的长期性,从而获得最佳的综合使用效果.%This paper studies and compares the structure and performance of two different types of burners including pre-mixing burners and diffusion burners used in large scale SRU with engineering examples, which provides certain reference for the model selection of such burners. Special designed burners for SRU are essential for the smooth operation of the unit, so it is necessary to consider the technical requirement, operation safety and long-term operation maintanence of the equiment throughtly and systematically when selecting burners for optimal comprehensive effect.

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

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

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

  7. Experience with natural gas/oxygen burners on a cupola furnace; Erfahrungen mit Erdgas/Sauerstoff-Brennern an einem Kupolofen

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, J. [Ruhrgas AG, Essen (Germany); Lemperle, M. [Kuettner GmbH und Co. KG, Essen (Germany); Wieting, T. [RWTH Aachen (Germany). Inst. fuer Eisenhuettenkunde; Wilczek, M [Frauenhofer Inst. UMSICHT (Germany); Struening, H. [Fritz Winter Eisengiesserei GmbH und Co. KG, Stadtallendorf (Germany); Frielingsdorf, O. [Air Products GmbH, Hattingen (Germany)

    2003-11-01

    The 'KUPOLOPT' joint research project has as its target the economic and ecological optimization of cupola furnaces in foundries. The use of natural gas/oxygen burners during foundry operation is being studied on Fritz Winter Eisengiesserei GmbH and Co. KG's cupola furnace with the objective of enhancing melting rate, reducing emissions and permitting re-utilization of foundry and other particulates. This work is also intended to improve the cupola-furnace process in economic terms, in order to enhance its competitiveness. This article presents the results of the first project phase, which served to investigate the natural gas/oxygen burner as an external supplier of energy. (orig.)

  8. Average Droplet Diameter Measurement and Results for Fuel Aerosol Injected by Certain Types of the Turbojet Burners

    Institute of Scientific and Technical Information of China (English)

    TadeuszOpara

    1997-01-01

    Measurement of the diameter of the fuel aerosol droplet is very important in the design of new type burners and in diagnostic process,Diffraction method is one of the most useful measuring procedures in this case.An investigation setup is presented enabling the determination of the substituting drop diameter in fuel aerosol stream created by aeroengine injectors the results obtained for K 108-767,K 108-012,37.03.9595,16.83.0310 types are presented.

  9. Female Struggle in Patriarchal Society-Comparative Interpretation of Gimmal and Crumbs of Agalloch Eaglewood-the First Incense Burner

    Institute of Scientific and Technical Information of China (English)

    李姝颖

    2014-01-01

    Zhang Ailin created so many various kinds of female charaters in her novels;females who own distinct characters and identities just have similar fates and struggles. This paper tries to probe into the similar fates and struggles of two heroines with dif-ferent identities in the same social background by analysing the novel Gimmal and Crumbs of Agalloch Eaglewood-the First In-cense Burner from perspective of feminism.

  10. Experimental study on NOx emission and unburnt carbon of a radial biased swirl burner for coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Shan Xue; Shi' en Hui; Qulan Zhou; Tongmo Xu [Xi' an Jiaotong University, Xi' an (China). State Key Laboratory of Multiphase Flow in Power Engineering

    2009-07-15

    Pilot tests were carried out on a 1 MW thermal pulverized coal fired testing furnace. Symmetrical combustion was implemented by use of two whirl burners with dual air adjustment. The burnout air device was installed in various places at the top of the main burner, which consists of a primary air pipe with a varying cross-section and an impact ring. In the primary air pipe, the air pulverized coal (PC) stream was separated into a whirling stream that was thick inside and thin outside, thus realizing the thin-thick distribution at the burner nozzle in the radial direction. From the comparative combustion tests of three coals with relatively great characteristic differences, Shaanbei Shenhua high rank bituminous coal (SH coal), Shanxi Hejin low rank bituminous coal (HJ coal), and Shanxi Changzhi meager coal (CZ coal), were obtained such test results as the primary air ratio, inner secondary air ratio, outer secondary air ratio, impact of the change of outer secondary air, change of the relative position for the layout of burnout air, change of the swirling intensity of the primary air and secondary air, etc., on the NOx emission, and unburnt carbon content in fly ash (CFA). At the same time, the relationship between the NOx emission and burnout ratio and affecting factors of the corresponding test items on the combustion stability and economic results were also acquired. The results may provide a vital guiding significance to engineering designs and practical applications. According to the experimental results, the influence of each individual parameter on NOx formation and unburned carbon in fly ash agrees well with the existing literature. In this study, the influences of various combinations of these parameters are also examined, thus providing some reference for the design of the radial biased swirl burner, the configuration of the furnace, and the distribution of the air. 23 refs., 14 figs., 2 tabs.

  11. Characterization of primary and secondary wood combustion products generated under different burner loads

    Science.gov (United States)

    Bruns, E. A.; Krapf, M.; Orasche, J.; Huang, Y.; Zimmermann, R.; Drinovec, L.; Močnik, G.; El-Haddad, I.; Slowik, J. G.; Dommen, J.; Baltensperger, U.; Prévôt, A. S. H.

    2015-03-01

    Residential wood burning contributes to the total atmospheric aerosol burden; however, large uncertainties remain in the magnitude and characteristics of wood burning products. Primary emissions are influenced by a variety of parameters, including appliance type, burner wood load and wood type. In addition to directly emitted particles, previous laboratory studies have shown that oxidation of gas-phase emissions produces compounds with sufficiently low volatility to readily partition to the particles, forming considerable quantities of secondary organic aerosol (SOA). However, relatively little is known about wood burning SOA, and the effects of burn parameters on SOA formation and composition are yet to be determined. There is clearly a need for further study of primary and secondary wood combustion aerosols to advance our knowledge of atmospheric aerosols and their impacts on health, air quality and climate. For the first time, smog chamber experiments were conducted to investigate the effects of wood loading on both primary and secondary wood combustion products. Products were characterized using a range of particle- and gas-phase instrumentation, including an aerosol mass spectrometer (AMS). A novel approach for polycyclic aromatic hydrocarbon (PAH) quantification from AMS data was developed and results were compared to those from GC-MS analysis of filter samples. Similar total particle mass emission factors were observed under high and average wood loadings; however, high fuel loadings were found to generate significantly higher contributions of PAHs to the total organic aerosol (OA) mass compared to average loadings. PAHs contributed 15 ± 4% (mean ±2 sample standard deviations) to the total OA mass in high-load experiments, compared to 4 ± 1% in average-load experiments. With aging, total OA concentrations increased by a factor of 3 ± 1 for high load experiments compared to 1.6 ± 0.4 for average-load experiments. In the AMS, an increase in PAH and

  12. Characterization of primary and secondary wood combustion products generated under different burner loads

    Directory of Open Access Journals (Sweden)

    E. A. Bruns

    2014-10-01

    Full Text Available Residential wood burning contributes significantly to the total atmospheric aerosol burden; however, large uncertainties remain in the magnitude and characteristics of wood burning products. Primary emissions are influenced by a variety of parameters, including appliance type, burner wood load and wood type. In addition to directly emitted particles, previous laboratory studies have shown that oxidation of gas phase emissions produces compounds with sufficiently low volatility to readily partition to the particles, forming significant quantities of secondary organic aerosol (SOA. However, relatively little is known about wood burning SOA and the effects of burn parameters on SOA formation and composition are yet to be determined. There is clearly a need for further study of primary and secondary wood combustion aerosols to advance our knowledge of atmospheric aerosols and their impacts on health, air quality and climate. For the first time, smog chamber experiments were conducted to investigate the effects of wood loading on both primary and secondary wood combustion products. Products were characterized using a range of particle and gas phase instrumentation, including an aerosol mass spectrometer (AMS. A novel approach for polycyclic aromatic hydrocarbon (PAH quantification from AMS data was developed and results were compared to those from GC-MS analysis of filter samples. Similar total particle mass emission factors were observed under high and average wood loadings, however, high fuel loadings were found to generate significantly higher contributions of PAHs to the total organic aerosol (OA mass compared to average loadings. PAHs contributed 15 ± 4% (mean ± 2 sample standard deviations to the total OA mass in high load experiments, compared to 4 ± 1% in average load experiments. With aging, total OA concentrations increased by a factor of 3 ± 1 for high load experiments compared to 1.6 ± 0.4 for average load experiments. In the AMS, an

  13. Numerical study of a jet-in-hot-coflow burner with hydrogen-addition using the Flamelet Generated Manifolds technique

    Science.gov (United States)

    Abtahizadeh, Seyed Ebrahim; van Oijen, Jeroen; de Goey, Philip

    2012-11-01

    Recently Mild combustion is subjected to intensive research because of its unique ability to provide high efficiency and low pollutant combustion simultaneously in industrial heating processes. In most practical Mild combustion applications, a fuel jet is ignited due to recirculation of hot burned gases. The impact of burned gases on autoignition and flame stabilization has been studied in a laboratory jet-in-hot-coflow (JHC) burner. Results of this study help us to understand recent experimental observations of the Delft group (DJHC burner) in which Dutch Natural Gas (DNG) is mixed with various amounts of H2. The main focus is on the modeling of autoignition in the DJHC burner by using the Flamelet Generated Manifolds (FGM) technique. In this technique, kinetic information is tabulated with a few controlling variables which results in a significant decrease in simulation time. The FGM tabulation has been performed using igniting laminar counterflow diffusion flames. Since H2 is present in the fuel composition, it is essential to include preferential diffusion effects in the table due to the high diffusivity of H2. Based on results, the FGM table is capable to reproduce the autoignition of hydrogen containing fuel predicted by detailed chemistry in 1D counterflow flames. The Authors gratefully acknowledge financial support of the Dutch Technology Foundation STW.

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

    Directory of Open Access Journals (Sweden)

    P. Koutmos

    2012-01-01

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

  15. Effect of oxyfuel burner ratio changes on energy efficiency in electric arc furnace at Co-Steel Lasco

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, M.J. [University of Toronto (Canada). Dept. of Mechanical and Industrial Engineering; Kournetas, N.G.; Sommerville, I.D.; McLean, A. [University of Toronto (Canada). Dept. of Metallurgy and Materials Science; Evenson, E. [Stantec Global Technologies Ltd., Mississauga (Canada); Guerard, J. [Co-Steel Lasco, Whitby (Canada)

    2001-07-01

    Trials were conducted on Co-Steel Lasco's electric arc furnace (EAF) to evaluate the effect of oxyfuel burner ratio changes on furnace energy efficiency and productivity. Carefully controlled trials with the collection of numerous process and sample data over 331 heats provided statistically significant results. The oxygen available for post-combustion in the furnace was increased by 19%. As the burners were operating at their maximum oxygen constraint, this was achieved by decreasing the natural gas consumption by 43%. Results of this study indicate that decreases in terms of specific electrical energy consumption (4.0%), power on time (5.0%), and tap to tap time (4.5%) were realised. Slag chemistry, electrode consumption, and yield were not affected. Measurement data support the finding that more heat was transferred into the steel with the post-combustion burners: a flat bath was achieved earlier; high bath temperatures were reached more quickly; power on time was reduced, leading to reduced electrical energy consumption. Analysis suggests that furnace thermal energy losses were reduced by less air inleakage, less incomplete methane combustion, and earlier achievement of foamy slag conditions. (author)

  16. Anisotropic grid adaptation in LES

    Science.gov (United States)

    Toosi, Siavash; Larsson, Johan

    2016-11-01

    The modeling errors depend directly on the grid (or filter) spacing in turbulence-resolving simulations (LES, DNS, DES, etc), and are typically at least as significant as the numerical errors. This makes adaptive grid-refinement complicated, since it prevents the estimation of the local error sources through numerical analysis. The present work attempts to address this difficulty with a physics-based error-source indicator that accounts for the anisotropy in the smallest resolved scales, which can thus be used to drive an anisotropic grid-adaptation process. The proposed error indicator is assessed on a sequence of problems, including turbulent channel flow and flows in more complex geometries. The formulation is geometrically general and applicable to complex geometries.

  17. Lipides et comportement alimentaire chez les enfants

    Directory of Open Access Journals (Sweden)

    Nicklaus Sophie

    2016-05-01

    Full Text Available Cet article analyse la place des lipides dans l’alimentation des jeunes enfants. Premièrement, il montre d’une part la contribution importante que devraient avoir les lipides aux apports énergétiques totaux des enfants de moins de deux ans, en raison de leur intérêt fonctionnel dans le développement neuronal et de leur effet potentiellement protecteur d’une obésité ultérieure; d’autre part, il souligne la faible contribution des lipides aux apports énergétiques totaux chez les enfants français, d’après les estimations disponibles, avec une minorité d’enfants pour lesquels les apports en lipides sont satisfaisants. Deuxièmement, il rapporte les connaissances disponibles concernant le contrôle « sensoriel » de la consommation de lipides. Chez les nouveau-nés et les nourrissons, quelques travaux portent sur les préférences pour les lipides, et indiquent l’absence d’une préférence pour les lipides. Chez les enfants, une teneur augmentée en lipides a parfois (mais pas toujours un effet positif sur l’appréciation d’un aliment, avec souvent une teneur optimale; mais elle n’est pas associée à une consommation plus élevée de l’aliment. Des teneurs élevées en lipides ont deux effets sur les apprentissages alimentaires. Chez des enfants de moins de 3 ans, un triplement de la densité énergétique par l’ajout de lipides est associé à la mise en place d’un rassasiement conditionné pour l’aliment concerné; chez des enfants plus âgés, un doublement de la densité énergétique par l’ajout de lipides, est associé à une augmentation de l’appréciation des flaveurs associées aux versions les plus riches en lipides. Des pistes d’études complémentaires sont discutées.

  18. Cotation de fabrication avec les normes ISO

    CERN Document Server

    Anselmetti, Bernard

    2010-01-01

    La cotation ISO en production impose de nouvelles méthodologies pour élaborer les documents de maîtrise de la qualité géométrique des produits : les dessins de phase, du brut et d'états intermédiaires pour la conformité des pièces et les fiches de production, de réglage, de contrôle et de surveillance pour la conformité des moyens de production. Une méthode de transfert unidirectionnelle simple permet d'établir des dessins de phase en normes ISO et d'optimiser la répartition des tolérances à isocapabilité. Cette cotation est déclinée en cotation d'état intermédiaire, de production et de réglage. Une méthode tridimensionnelle est proposée pour prendre en compte les effets des défauts angulaires. Une maquette montre les fonctionnalités envisageables pour les futurs outils d'aides au tolérancement de fabrication au sein de la CFAO. De nombreux exercices illustrent les différentes démarches. Ce Manuel de tolérancement est principalement destiné aux préparateurs méthodes et aux c...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-06-13

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

  20. Fully-Enclosed Ceramic Micro-burners Using Fugitive Phase and Powder-based Processing

    Science.gov (United States)

    Do, Truong; Shin, Changseop; Kwon, Patrick; Yeom, Junghoon

    2016-08-01

    Ceramic-based microchemical systems (μCSs) are more suitable for operation under harsh environments such as high temperature and corrosive reactants compared to the more conventional μCS materials such as silicon and polymers. With the recent renewed interests in chemical manufacturing and process intensification, simple, inexpensive, and reliable ceramic manufacturing technologies are needed. The main objective of this paper is to introduce a new powder-based fabrication framework, which is a one-pot, cost-effective, and versatile process for ceramic μCS components. The proposed approach employs the compaction of metal-oxide sub-micron powders with a graphite fugitive phase that is burned out to create internal cavities and microchannels before full sintering. Pure alumina powder has been used without any binder phase, enabling more precise dimensional control and less structure shrinkage upon sintering. The key process steps such as powder compaction, graphite burnout during partial sintering, machining in a conventional machine tool, and final densification have been studied to characterize the process. This near-full density ceramic structure with the combustion chamber and various internal channels was fabricated to be used as a micro-burner for gas sensing applications.

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

    KAUST Repository

    Ismail, Mohamed

    2015-01-01

    A novel curved wall-jet (CWJ) burner was designed for flame synthesis, by injecting precursors through a center tube and by supplying fuel/air mixtures as an annular-inward jet for rapid mixing of the precursors in the reaction zone. Titanium dioxide (TiO2) and silicon dioxide (SiO2) nanoparticles were produced in ethylene (C2H4)/air premixed flames using titanium tetraisopropoxide (TTIP) and hexamethyldisiloxane (HMDSO) as the precursors, respectively. Particle image velocimetry measurements confirmed that the precursors can be injected into the flames without appreciably affecting flow structure. The nanoparticles were characterized using X-ray diffraction, Raman spectroscopy, the Brunauer-Emmett-Teller (BET) method, and high-resolution transmission electron microscopy. In the case of TiO2, the phase of nanoparticles could be controlled by adjusting the equivalence ratio, while the particle size was dependent on the precursor loading rate and the flame temperature. The synthesized TiO2 nanoparticles exhibited high crystallinity and the anatase phase was dominant at high equivalence ratios (φ > 1.3). In the case of SiO2, the particle size could be controlled from 11 to 18 nm by adjusting the precursor loading rate. © 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

  2. Laminar burn rates of gun propellants measured in the high-pressure strand burner

    Energy Technology Data Exchange (ETDEWEB)

    Reaugh, J. E., LLNL

    1997-10-01

    The pressure dependence of the laminar burn rate of gun propellants plays a role in the design and behavior of high-performance guns. We have begun a program to investigate the effects of processing variables on the laminar burn rates, using our high-pressure strand burner to measure these rates at pressures exceeding 700 MPa. We have burned JA2 and M43 propellant samples, provided by Dr. Arpad Juhasz, ARL, from propellant lots previously used in round-robin tests. Our results at room temperature are in accord with other measurements. In addition, we present results measured for propellant that has been preheated to 50 C before burning. We used our thermochemical equilibrium code, CHEETAH, to help interpret the simultaneous pressure and temperature measurements taken during the testing, and show examples of its use. It has been modified to provide performance measures and equations of state for the products that are familiar to the gun-propellant community users of BLAKE.

  3. Analysis of Reactor Deployment Scenarios with Introduction of SFR Breakeven Reactors and Burners Using DANESS Code

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young In; Hahn, Do Hee; Won, Byung Chool; Lee, Dong Uk

    2008-01-15

    Using the DANESS code newly employed for future scenario analysis, reactor deployment scenarios with the introduction of sodium cooled fast reactors(SFRs) having different conversion ratios in the existing PWRs dominant nuclear fleet have been analyzed to find the SFR deployment strategy for replacing PWRs with the view of a spent fuel reduction and an efficient uranium utilization through its reuse in a closed nuclear fuel cycle. Descriptions of the DANESS code and how to use are briefly given from the viewpoint of its first application. The use of SFRs and recycling of TRUs by reusing PWR spent fuel leads to the substantial reduction of the amount of PWR spent fuel and environmental burden by decreasing radiotoxicity of high level waste, and a significant improvement on the natural uranium resources utilization. A continuous deployment of burners effectively decreases the amount of PWR spent fuel accumulation, thus lightening the burden for PWR spent fuel management. An introduction of breakeven reactors effectively reduces the uranium demand through producing excess TRU during the operation, thus contributing to a sustainable nuclear power development. With SFR introduction starting in 2040, PWRs will remain as a main power reactor type till 2100 and SFRs will be in support of waste minimization and fuel utilization.

  4. Laser Metal Deposition as Repair Technology for a Gas Turbine Burner Made of Inconel 718

    Science.gov (United States)

    Petrat, Torsten; Graf, Benjamin; Gumenyuk, Andrey; Rethmeier, Michael

    Maintenance, repair and overhaul of components are of increasing interest for parts of high complexity and expensive manufacturing costs. In this paper a production process for laser metal deposition is presented, and used to repair a gas turbine burner of Inconel 718. Different parameters for defined track geometries were determined to attain a near net shape deposition with consistent build-up rate for changing wall thicknesses over the manufacturing process. Spot diameter, powder feed rate, welding velocity and laser power were changed as main parameters for a different track size. An optimal overlap rate for a constant layer height was used to calculate the best track size for a fitting layer width similar to the part dimension. Deviations in width and height over the whole build-up process were detected and customized build-up strategies for the 3D sequences were designed. The results show the possibility of a near net shape repair by using different track geometries with laser metal deposition.

  5. Oxy-Combustion Burner and Integrated Pollutant Removal Research and Development Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Mark Schoenfield; Manny Menendez; Thomas Ochs; Rigel Woodside; Danylo Oryshchyn

    2012-09-30

    A high flame temperature oxy-combustion test facility consisting of a 5 MWe equivalent test boiler facility and 20 KWe equivalent IPR® was constructed at the Hammond, Indiana manufacturing site. The test facility was operated natural gas and coal fuels and parametric studies were performed to determine the optimal performance conditions and generated the necessary technical data required to demonstrate the technologies are viable for technical and economic scale-up. Flame temperatures between 4930-6120F were achieved with high flame temperature oxy-natural gas combustion depending on whether additional recirculated flue gases are added to balance the heat transfer. For high flame temperature oxy-coal combustion, flame temperatures in excess of 4500F were achieved and demonstrated to be consistent with computational fluid dynamic modeling of the burner system. The project demonstrated feasibility and effectiveness of the Jupiter Oxygen high flame temperature oxy-combustion process with Integrated Pollutant Removal process for CCS and CCUS. With these technologies total parasitic power requirements for both oxygen production and carbon capture currently are in the range of 20% of the gross power output. The Jupiter Oxygen high flame temperature oxy-combustion process has been demonstrated at a Technology Readiness Level of 6 and is ready for commencement of a demonstration project.

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

    KAUST Repository

    Mansour, Morkous S.

    2015-08-02

    This study concerns the flame dynamics of a curved-wall jet (CWJ) stabilized turbulent premixed flame as it approaches blow-off conditions. Time resolved OH planar laser-induced fluorescence (PLIF) delineated reaction zone contours and simultaneously stereoscopic particle image velocimetry (SPIV) quantified the turbulent flow field features. Ethylene/air flames were stabilized in CWJ burner to determine the sequence of events leading to blowoff. For stably burning flames far from blowoff, flames are characterized with a recirculation zone (RZ) upstream for flame stabilization followed by an intense turbulent interaction jet (IJ) and merged-jet regions downstream; the flame front counterparts the shear layer vortices. Near blowoff, as the velocity of reactants increases, high local stretch rates exceed the extinction stretch rates instantaneously resulting in localized flame extinction along the IJ region. As Reynolds number (Re) increases, flames become shorter and are entrained by larger amounts of cold reactants. The increased strain rates together with heat loss effects result in further fragmentation of the flame, eventually leading to the complete quenching of the flame. This is explained in terms of local turbulent Karlovitz stretch factor (K) and principal flow strain rates associated with C contours. Hydrogen addition and increasing the RZ size lessen the tendency of flames to be locally extinguished.

  7. Burner Rig Hot Corrosion of Five Ni-Base Alloys Including Mar-M247

    Science.gov (United States)

    Nesbitt, James A.; Helmink, R.; Harris, K.; Erickson, G.

    2000-01-01

    The hot corrosion resistance of four new Ni-base superalloys was compared to that of Mar-M247 by testing in a Mach 0.3 burner rig at 900 C for 300 1-hr cycles. While the Al content was held the same as in the Mar-M247, the Cr and Co levels in the four new alloys were decreased while other strengthening elements (Re, Ta) were increased. Surprisingly, despite their lower Cr and Co contents, the hot corrosion behavior of all four new alloys was superior to that of the Mar-M247 alloy. The Mar-M247 alloy began to lose weight almost immediately whereas the other four alloys appeared to undergo an incubation period of 50-150 1-hr cycles. Examination of the cross-sectional microstructures showed regions of rampant corrosion attack (propagation stage) in all five alloys after 300 1-hr cycles . This rampant corrosion morphology was similar for each of the alloys with Ni and Cr sulfides located in an inner subscale region. The morphology of the attack suggests a classic "Type I", or high temperature, hot corrosion attack.

  8. Le zapping, les ethnologues, et leurs Indiens

    Directory of Open Access Journals (Sweden)

    Frédérique Langue

    2005-06-01

    Full Text Available Comme toujours s'agissant des expositions mises en scène au Grand Palais, la présentation est parfaite, impeccable. La mise en valeur des objets venus aussi bien de musées brésiliens qu'européens, et les commentaires qui les accompagnent, orientent le visiteur dans un labyrinthe "exotique" de poteries et d'objets de plume, coupé de temps à autre de documentaires portant sur les rituels amérindiens, chants psalmodiques à l'appui. L'auditoire y semble comme vissé sur place, davantage d'ailleur...

  9. New Light Alloys (Les Nouveaux Alliages Legers)

    Science.gov (United States)

    1990-09-01

    abord~s lors de la conference on distingue: la physique des m~taux et les traitements, les caract~ristiques des materiaux existants et les perspectives...I’Ngide du Panel AGARD des Structures et Materiaux . iii List of Authors/Speakers Lecture Series Director: IGA P.Costa Directeur Scientifique des Mat...rairalement amorphes, pr~sentent l’avantage de pouvoir ktre synth~tisds A temp&ature ambiante soit A partir de suspensions colloidales d’oxydes ou d’hydroxydes

  10. Blending of hydrogen in natural gas distribution systems. Volume II. Combustion tests of blends in burners and appliances. Final report, June 1, 1976--August 30, 1977. [8, 11, 14, 20, 22, 25, and 31% hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-10-01

    The emerging ''hydrogen economy'' is a strong contender as one method to supplement or extend the domestic natural gas supply. This volume of the subject study ''Blending Hydrogen in Natural Gas Distribution Systems'' describes combustion studies to determine the maximum amount of hydrogen that can be blended in natural gas and utilized satisfactorily in typical appliances with no adjustment or conversion. Eleven pilot burners and twenty-three main burners typical of those in current use were operated on hydrogen-natural gas mixtures containing approximately 8, 11, 14, 20, 22, 25, and 31 percent, by volume, hydrogen. The eleven pilot burners and thirteen main burners were tested outside the appliance they were a part of. Ten main burners were tested in their respective appliances. Performance of the various burners tested are as follows: (1) Gas blends containing more than 6 to 11% hydrogen are the limiting mixtures for target type pilot burners. (2) Gas blends containing more than 20 to 22% hyrogen are the limiting mixtures for main burners operating in the open. (3) Gas blends containing more than 22 to 25% hydrogen are the limiting mixtures for main burners tested in appliances. (4) Modification of the orifice in target pilots or increasing the supply pressure to a minimum of 7 inches water column will permit the use of gas blends with 20% hydrogen.

  11. Fundamental research of development and optimization of ceramic recuperative burners. Final report; Grundlagenuntersuchung zur Entwicklung und Optimierung keramischer Rekuperatorbrenner. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Brune, M.; Boss, M.; Flamme, M.; Lynen, A.; Wuenning, J.A.; Wuenning, J.G.; Dittmann, H.J.; Seltmann, M.

    1998-10-01

    A significant reduction of CO{sub 2} emissions from high temperature processes can be accomplished by means of heat recovery from the flue gases. For several years now, recuperative burners consisting of reaction-bonded silicon carbide have been available on the market for temperatures above 110 C and for service with corrosive flue gases, where chromium-nickel steels cannot be used. With support from the BMBF and the gas industry, the ceramic recuperative burners have been developed for highr outputs and efficiencies. The relative air preheating, the pressure drop on the air- and flue gas side, the flue gas emission and the production costs have been considered for the development and optimization of full ceramic recuperative burners. Parallel to the development of the new recuperative burners, calculations with the CFD-programm FLUENT have been carried out for the description of the heat transfer processes in the recuperator and the combustion processes. With the help of these calculations the development expenditure could be reduced. Due to the development of the production technical possibilities for RbSiC-components, it has been proven possible to produce recuperators with surface structures using the slip casting technique which on the one hand can be manufactured at a rational price level and, on the other, achieve a relative air preheating of up to {epsilon}=0.8. By the new burner concepts the NO{sub x} emission could be lowered under the limit of the German TA Luft even at highest air preheating temperatures. For the direct heating the ceramic recuperative burners comes into action, where high application temperatures, e.g. in furnace forges or ceramic kilns, or aggressive flue gases are present. For the indirect heating in heat treatment installations the ceramic recuperative burners are used in connection with full ceramic radiant tubes. (orig.) [Deutsch] Bei Hochtemperaturprozessen ist eine erhebliche Verringerung des CO{sub 2}-Ausstosses durch

  12. Quand le crédit à la consommation classe les gens et les choses

    DEFF Research Database (Denmark)

    Ossandón, José

    2012-01-01

    Le développement du crédit à la consommation est l’une des principales manifestations de la financiarisation de l’économie. Les éléments institutionnels et techniques qui lui ont donné forme tels que les dispositifs d’attribution de score aux consommateurs, de détermination des taux ou encore les...... structuration et que ces travaux empiriques contribuent de façon originale à la sociologie....

  13. Les produits de la mer se diversifient

    OpenAIRE

    Penez, Jacqueline

    1993-01-01

    L'idée qui prévaut dans l'opinion du public est la surexploitation de la mer. Or, seule une très faible partie de la biomasse marine est prélevée via les pêches et cultures marines. Traditionnellement appréciés pour leurs qualités nutritionnelles, les poissons représentent de surcroît une importante source de molécules dont les activités biologiques intéressent au plus haut point les industries pharmaceutiques et cosmétiques La part de ces molécules marines, comparée aux matières premières d'...

  14. A Les Houches Interface for BSM Generators

    Energy Technology Data Exchange (ETDEWEB)

    Alwall, J.; /SLAC; Boos, E.; Dudko, L.; /SINP, Moscow; Gigg, M.; /Durham U., IPPP; Herquet, M.; /Louvain U., CP3; Pukhov, A.; /Moscow State U.; Richardson, P.; /Durham U., IPPP /CERN; Sherstnev, A.; /Cambridge U. /SINP, Moscow; Skands, P.; /CERN /Fermilab

    2007-12-01

    We propose to combine and slightly extend two existing 'Les Houches Accords' to provide a simple generic interface between beyond-the-standard-model parton-level and event-level generators. All relevant information--particle content, quantum numbers of new states, masses, cross sections, parton-level events, etc.--is collected in one single file, which adheres to the Les Houches Event File (LHEF) standard.

  15. A Les Houches Interface for BSM Generators

    Energy Technology Data Exchange (ETDEWEB)

    Alwall, J.; /SLAC; Boos, E.; Dudko, L.; /SINP, Moscow; Gigg, M.; /Durham U., IPPP; Herquet, M.; /Louvain U., CP3; Pukhov, A.; /Moscow State U.; Richardson, P.; /Durham U., IPPP /CERN; Sherstnev, A.; /Cambridge U. /SINP, Moscow; Skands, P.; /CERN /Fermilab

    2008-01-23

    We propose to combine and slightly extend two existing 'Les Houches Accords' to provide a simple generic interface between beyond-the-standard-model parton-level and event-level generators. All relevant information--particle content, quantum numbers of new states, masses, cross sections, parton-level events, etc.--is collected in one single file, which adheres to the Les Houches Event File (LHEF) standard.

  16. Les atomes existent-ils vraiment ?

    CERN Document Server

    Diu, Bernard

    1997-01-01

    Peu de notions scientifiques ont autant suscité l'imagination spéculative que l'entropie thermodynamique. Tous les systèmes organisés - les sociétés, les êtres vivants - seraient promis à la décadence, à la mort, forcément. Ce livre expose en toute clarté le développement historique et conceptuel de la thermodynamique. Née du désir de comprendre et de maîtriser le fonctionnement des machines à vapeur - emblème de nos sociétés industrielles -, elle est devenue la science des corps, de tous les corps à notre échelle. Mais elle se passait sans états d'âme de l'hypothèse atomique. Elle a donc été battue en brèche par la mécanique statistique qui faisait droit aux impératifs dictés par la structure atomique des corps. Après une lutte épique, et même sanglante, thermodynamique et mécanique statistique se sont réconciliées sur les fondements de la seconde mais avec les techniques de la première. Ce livre se lit comme un roman de physique contemporaine.

  17. LES versus DNS: A comparative study

    Science.gov (United States)

    Shtilman, L.; Chasnov, J. R.

    1992-01-01

    We have performed Direct Numerical Simulations (DNS) and Large Eddy Simulations (LES) of forced isotropic turbulence at moderate Reynolds numbers. The subgrid scale model used in the LES is based on an eddy viscosity which adjusts instantaneously the energy spectrum of the LES to that of the DNS. The statistics of the large scales of the DNS (filtered DNS field or fDNS) are compared to that of the LES. We present results for the transfer spectra, the skewness and flatness factors of the velocity components, the PDF's of the angle between the vorticity and the eigenvectors of the rate of strain, and that between the vorticity and the vorticity stretching tensor. The above LES statistics are found to be in good agreement with those measured in the fDNS field. We further observe that in all the numerical measurements, the trend was for the LES field to be more gaussian than the fDNS field. Future research on this point is planned.

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

    Directory of Open Access Journals (Sweden)

    Tzu-Hsiang Yen, Wen-Tang Hong, Yu-Ching Tsai, Hung-Yu Wang, Cheng-Nan Huang, Chien-Hsiung Lee, Bao-Dong Chen

    2010-07-01

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

  19. Premixed Combustion of Kapok (ceiba pentandra seed oil on Perforated Burner

    Directory of Open Access Journals (Sweden)

    I.K.G. Wirawan

    2014-05-01

    Full Text Available Availability of fossil fuels in the world decrease gradually due to excessive fuel exploitation. This situations push researcher to look for alternative fuels as a source of renewable energy, one of them is kapok (ceiba pentandra seed oil. The aim this study was to know the behavior of laminar burning velocity, secondary Bunsen flame with open tip, cellular and triple flame. Premixed combustion of kapok seed oil was studied experimentally on perforated burner with equivalence ratio (φ varied from 0.30 until 1.07. The results showed that combustion of glycerol requires a large amount of air so that laminar burning velocity (SL is the highest at very lean mixture (φ =0.36 in the form of individual Bunsen flame on each of the perforated plate hole.  Perforated and secondary Bunsen flame both reached maximum SL similar with that of ethanol and higher than that of hexadecane. Slight increase of φ decreases drastically SL of perforated and secondary Bunsen flame. When the mixture was enriched, secondary Bunsen and perforated flame disappears, and then the flame becomes Bunsen flame with open tip and triple flame (φ = 0.62 to 1.07. Flame was getting stable until the mixture above the stoichiometry. Being isolated from ambient air, the SL of perforated flame, as well as secondary Bunsen flame, becomes equal with non-isolated flame. This shows the decreasing trend of laminar burning velocity while φ is increasing. When the mixture was enriched island (φ = 0.44 to 0.48 and petal (φ = 0.53 to 0.62 cellular flame take place. Flame becomes more unstable when the mixture was changed toward stoichiometry.

  20. Holy Smoke in Medieval Funerary Rites: Chemical Fingerprints of Frankincense in Southern Belgian Incense Burners

    Science.gov (United States)

    Baeten, Jan; Deforce, Koen; Challe, Sophie; De Vos, Dirk; Degryse, Patrick

    2014-01-01

    Frankincense, the oleogum resin from Boswellia sp., has been an early luxury good in both Western and Eastern societies and is particularly used in Christian funerary and liturgical rites. The scant grave goods in late medieval burials comprise laterally perforated pottery vessels which are usually filled with charcoal. They occur in most regions of western Europe and are interpreted as incense burners but have never been investigated with advanced analytical techniques. We herein present chemical and anthracological results on perforated funerary pots from 4 Wallonian sites dating to the 12–14th century AD. Chromatographic and mass spectrometric analysis of lipid extracts of the ancient residues and comparison with extracts from four Boswellia species clearly evidence the presence of degraded frankincense in the former, based on characteristic triterpenoids, viz. boswellic and tirucallic acids, and their myriad dehydrated and oxygenated derivatives. Cembrane-type diterpenoids indicate B. sacra (southern Arabia) and B. serrata (India) as possible botanical origins. Furthermore, traces of juniper and possibly pine tar demonstrate that small amounts of locally available fragrances were mixed with frankincense, most likely to reduce its cost. Additionally, markers of ruminant fats in one sample from a domestic context indicate that this vessel was used for food preparation. Anthracological analysis demonstrates that the charcoal was used as fuel only and that no fragrant wood species were burned. The chars derived from local woody plants and were most likely recovered from domestic fires. Furthermore, vessel recycling is indicated by both contextual and biomarker evidence. The results shed a new light on funerary practices in the Middle Ages and at the same time reveal useful insights into the chemistry of burned frankincense. The discovery of novel biomarkers, namely Δ2-boswellic acids and a series of polyunsaturated and aromatic hydrocarbons, demonstrates the

  1. Holy smoke in medieval funerary rites: chemical fingerprints of frankincense in southern Belgian incense burners.

    Directory of Open Access Journals (Sweden)

    Jan Baeten

    Full Text Available Frankincense, the oleogum resin from Boswellia sp., has been an early luxury good in both Western and Eastern societies and is particularly used in Christian funerary and liturgical rites. The scant grave goods in late medieval burials comprise laterally perforated pottery vessels which are usually filled with charcoal. They occur in most regions of western Europe and are interpreted as incense burners but have never been investigated with advanced analytical techniques. We herein present chemical and anthracological results on perforated funerary pots from 4 Wallonian sites dating to the 12-14th century AD. Chromatographic and mass spectrometric analysis of lipid extracts of the ancient residues and comparison with extracts from four Boswellia species clearly evidence the presence of degraded frankincense in the former, based on characteristic triterpenoids, viz. boswellic and tirucallic acids, and their myriad dehydrated and oxygenated derivatives. Cembrane-type diterpenoids indicate B. sacra (southern Arabia and B. serrata (India as possible botanical origins. Furthermore, traces of juniper and possibly pine tar demonstrate that small amounts of locally available fragrances were mixed with frankincense, most likely to reduce its cost. Additionally, markers of ruminant fats in one sample from a domestic context indicate that this vessel was used for food preparation. Anthracological analysis demonstrates that the charcoal was used as fuel only and that no fragrant wood species were burned. The chars derived from local woody plants and were most likely recovered from domestic fires. Furthermore, vessel recycling is indicated by both contextual and biomarker evidence. The results shed a new light on funerary practices in the Middle Ages and at the same time reveal useful insights into the chemistry of burned frankincense. The discovery of novel biomarkers, namely Δ2-boswellic acids and a series of polyunsaturated and aromatic hydrocarbons

  2. Holy smoke in medieval funerary rites: chemical fingerprints of frankincense in southern Belgian incense burners.

    Science.gov (United States)

    Baeten, Jan; Deforce, Koen; Challe, Sophie; De Vos, Dirk; Degryse, Patrick

    2014-01-01

    Frankincense, the oleogum resin from Boswellia sp., has been an early luxury good in both Western and Eastern societies and is particularly used in Christian funerary and liturgical rites. The scant grave goods in late medieval burials comprise laterally perforated pottery vessels which are usually filled with charcoal. They occur in most regions of western Europe and are interpreted as incense burners but have never been investigated with advanced analytical techniques. We herein present chemical and anthracological results on perforated funerary pots from 4 Wallonian sites dating to the 12-14th century AD. Chromatographic and mass spectrometric analysis of lipid extracts of the ancient residues and comparison with extracts from four Boswellia species clearly evidence the presence of degraded frankincense in the former, based on characteristic triterpenoids, viz. boswellic and tirucallic acids, and their myriad dehydrated and oxygenated derivatives. Cembrane-type diterpenoids indicate B. sacra (southern Arabia) and B. serrata (India) as possible botanical origins. Furthermore, traces of juniper and possibly pine tar demonstrate that small amounts of locally available fragrances were mixed with frankincense, most likely to reduce its cost. Additionally, markers of ruminant fats in one sample from a domestic context indicate that this vessel was used for food preparation. Anthracological analysis demonstrates that the charcoal was used as fuel only and that no fragrant wood species were burned. The chars derived from local woody plants and were most likely recovered from domestic fires. Furthermore, vessel recycling is indicated by both contextual and biomarker evidence. The results shed a new light on funerary practices in the Middle Ages and at the same time reveal useful insights into the chemistry of burned frankincense. The discovery of novel biomarkers, namely Δ2-boswellic acids and a series of polyunsaturated and aromatic hydrocarbons, demonstrates the high

  3. Advanced Fuel Cycle Economic Analysis of Symbiotic Light-Water Reactor and Fast Burner Reactor Systems

    Energy Technology Data Exchange (ETDEWEB)

    D. E. Shropshire

    2009-01-01

    The Advanced Fuel Cycle Economic Analysis of Symbiotic Light-Water Reactor and Fast Burner Reactor Systems, prepared to support the U.S. Advanced Fuel Cycle Initiative (AFCI) systems analysis, provides a technology-oriented baseline system cost comparison between the open fuel cycle and closed fuel cycle systems. The intent is to understand their overall cost trends, cost sensitivities, and trade-offs. This analysis also improves the AFCI Program’s understanding of the cost drivers that will determine nuclear power’s cost competitiveness vis-a-vis other baseload generation systems. The common reactor-related costs consist of capital, operating, and decontamination and decommissioning costs. Fuel cycle costs include front-end (pre-irradiation) and back-end (post-iradiation) costs, as well as costs specifically associated with fuel recycling. This analysis reveals that there are large cost uncertainties associated with all the fuel cycle strategies, and that overall systems (reactor plus fuel cycle) using a closed fuel cycle are about 10% more expensive in terms of electricity generation cost than open cycle systems. The study concludes that further U.S. and joint international-based design studies are needed to reduce the cost uncertainties with respect to fast reactor, fuel separation and fabrication, and waste disposition. The results of this work can help provide insight to the cost-related factors and conditions needed to keep nuclear energy (including closed fuel cycles) economically competitive in the U.S. and worldwide. These results may be updated over time based on new cost information, revised assumptions, and feedback received from additional reviews.

  4. Preliminary studies of a new accelerator-driven minor actinide burner in industrial scale

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xunzhao; Zhou, Shengcheng [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049, Shaanxi (China); Zheng, Youqi, E-mail: yqzheng@mail.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049, Shaanxi (China); Wang, Kunpeng [Nuclear and Radiation Safety Center, PO Box 8088, No. 54, Beijing 100082 (China); Wu, Hongchun [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049, Shaanxi (China)

    2015-10-15

    Highlights: • A new accelerator-driven minor actinide (MA) burner was proposed. • Comprehensive design of spallation target, fuel assembly and subcritical core was performed. • Preliminary safety analyses indicate the inherent safety of the core in the reactivity insertion (500 pcm) and beam overpower (50% increase) transients. - Abstract: Pursuing high transmutation rate of minor actinide (MA), a preliminary conceptual design of a lead-bismuth (LBE) cooled accelerator-driven system (ADS) is proposed in this study. Parametric studies are performed to optimize the neutronics and thermal–hydraulics performances. The proton energy and axial position of the proton beam impact is investigated to obtain high neutron source efficiency and spallation neutron yield. The influences of MA/Pu mixing ratio and the ratio of pin pitch to diameter (P/D) are also optimized to control the burnup reactivity swing and the minimum coolant velocity for adequate cooling. To reduce the power peak, three kinds of power flattening techniques are adopted and compared. The results show that the inert matrix ratio zone loading method seems more versatile. Based on the analyses, an optimized three zone loading pattern is proposed for the 800 MWth subcritical core. The total transmutation rate of MA is 328.8 kg per effective full power year. Preliminary safety analyses based on the balance of power method (BOP) are performed and the results show that in the reactivity insertion and beam overpower transients, the core shows inherent safety, but the scram is necessary by cutting off the beam current to protect the core from possible damages caused by the loss of flow.

  5. Flat-flame burner studies of pulverized-coal combustion. Experimental results on char reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Peck, R.E.; Shi, L.

    1996-12-01

    Structure of laminar, premixed pulverized-coal flames in a 1-D reactor has been studied with emphasis on char reactivity. A 1.1-meter-long tube furnace accommodated high-temperature environments and long residence times for the laminar flames produced by a flat-flame, coal-dust burner. Experiments were conducted at different operating conditions (fuel type/size, fuel-air ratio). Measurements included solid sample composition, major gas species and hydrocarbon species concentrations, and gas- and particle-phase line-of-sight temperatures at different axial locations in flames. Degree of char burnout increased with coal volatiles content and decreased with coal particle size. Combustion in furnace was in oxidizer-deficient environment and higher burnout was achieved as the fuel-air ratio neared stoichiometric. For 0-45 {mu}m particles most of the fixed carbon mass loss occurred within 5 cm of the furnace inlet, and char reaction was slow downstream due to low oxidizer concentrations. Fixed carbon consumption of the 45-90 {mu}m particles generally was slower than for the small particles. About 40%-80% of the fixed carbon was oxidized in the furnace. Primary volatiles mass loss occurred within the first 4.5 cm, and more than 90% of the volatiles were consumed in the flames. The flames stabilized in the furnace produced less CH{sub 4} and H{sub 2} in the burnt gas than similar unconfined flames. NO concentrations were found to decrease along the furnace and to increase with decreasing fuel/air ratio. Temperature measurement results showed that gas-phase temperatures were higher than solid-phase temperatures. Temperatures generally decreased with decreasing volatiles content and increased as the equivalence ratio approached one. The results can be used to interpret thermochemical processes occurring in pulverized-coal combustion. (au) 15 refs.

  6. Les Elements Legers: Diffusion dans les Enveloppes Stellaires et Implications Cosmologiques

    Science.gov (United States)

    Richer, Jacques

    1992-01-01

    Les observations des abondances des elements legers (Z premieres minutes de l'expansion de l'Univers. Nous tenons compte de la difference possible entre l'abondance primordiale de Li et les abondances observees dans les plus vieilles etoiles. Cette difference (un facteur 2, environ) est estimee en construisant des modeles evolutifs d'etoiles peu massives de Population II, incluant la sedimentation gravitationnelle du lithium et de l'helium. Ces modeles montrent egalement que les ages des vieux amas stellaires sont grandement surestimes lorsqu'ils sont determines a partir de modeles stellaires n'incluant pas l'effet de la diffusion de He. Nous calculons ensuite comment evoluent les abondances de Li et Be dans des etoiles plus massives et plus jeunes, de la pre-sequence principale ou de la ZAMS, jusqu'a l'epuisement de leur hydrogene central. Les modeles incluent la sedimentation simultanee de l'helium a travers l'enveloppe. Une approche hierarchique (evolution du coeur--evolution de l'enveloppe --tri des elements traces) est utilisee pour simuler efficacement le grand nombre d'etoiles necessaire pour la construction d'isochrones. Une attention particuliere est portee aux consequences de la sedimentation de He sur l'etendue des zones convectives, et sur la diffusion de Li et Be. Les forces radiatives agissant sur ces deux elements sont calculees en detail a partir des donnees atomiques. Les etoiles simulees correspondent approximativement aux types spectraux A, F, et AmFm. Les abondances de Li et Be observees dans les etoiles jeunes de ces types sont comparees a nos predictions dans le but d'identifier les conditions ou la diffusion peut etre le processus principal. ou un processus important controlant les abondances superficielles observees. La position et la profondeur du "trou du lithium" observe parmi les etoiles F des Hyades et d'autres amas jeunes, sont reproduites sans l'aide de parametres ajustables; cet accord n'est obtenu que si les recentes opacites OPAL

  7. Les paradoxes du littoral Swahili

    Directory of Open Access Journals (Sweden)

    François Bart

    2008-10-01

    Full Text Available Le contact entre l'océan Indien occidental et le continent africain a forgé l'identité et l'originalité du littoral swahili. Cette interface, longue d'environ 2 000 kilomètres, du sud de la Somalie au nord du Mozambique, constitue un monde original où, au gré de traditions anciennes de circulation maritime et continentale se sont diffusées et mêlées des influences culturelles venues du continent africain, de la péninsule arabique et de la péninsule indienne. Le développement du continent, du littoral et des archipels s'inscrit dans une double logique de fragmentation et d'ouverture au monde. Dans cette vaste aire géographique, le rôle de relais des îles et des axes de pénétration continentale à partir des ports est essentiel.The identity and the original features of the Swahili seashore mainly proceed from the contact of African mainland and western indian Ocean. This coastal interface, stretching over 2 000 kilometres from southern Somalia to northern Mozambique, is characterized by ancient traditions of trade movements through maritime areas and mainland as well, which spread and mixed different cultural influences originating from Africa and both Arabic and Indian peninsulas. The development of this area is linked to both fragmentation and opening dynamics. In such a wide area, the relaying function of islands and continental corridors from main harbours is very important.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-09-15

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

  9. Fundamental study for the development and optimization of ceramic recuperator burners; Grundlagenuntersuchung zur Entwicklung und Optimierung keramischer Rekuperatorbrenner

    Energy Technology Data Exchange (ETDEWEB)

    Brune; Boss, M.; Flamme, M. [Gaswaerme-Institut e.V., Essen (Germany); Lynen, A. [Schunk Ingenieurkeramik GmbH, Willich (Germany); Wuenning, J.A.; Wuenning, J.G. [WS Waermeprozesstechnik GmbH, Renningen (Germany); Dittmann, H.J.; Seltmann, M. [Kromschroeder Prozesswaerme GmbH, Wuppertal (Germany)

    1998-06-01

    A significant reduction of CO{sub 2} emissions from high-temperature processes can be accomplished by means of recovery of heat from the flue gases. For several years now, recuperator burners consisting of reaction-bonded silicon carbide have been available on the market for temperatures above 1100 C and for service with corrosive flue gases, where chromium-nickel steels cannot be used. Ceramic recuperative burners for higher outputs and efficiencies have been developed with support from the BMBF and the gas industry. It has proven possible to produce ceramic recuperators which on the one hand can be manufactured at a rational price level and, on the other, achieve a relative air pre-heat of up to {epsilon}=0.8. In addition to optimization of these heat exchange elements, new burner systems by means of which NO{sub x} emissions can be reduced have also been developed. (orig.) [Deutsch] Bei Hochtemperaturprozessen ist eine erhebliche Verringerung des CO{sub 2}-Ausstosses durch Waermerueckgewinnung aus den Abgasen moeglich. Fuer Temperaturen oberhalb 1100 C und bei korrosiven Abgasen, bei denen Chrom-Nickel-Staehle nicht eingesetzt werden koennen, sind seit einigen Jahren Rekuperatorbrenner aus reaktionsgebundenem Siliciumcarbid auf dem Markt. Mit Foerderung vom BMBF und von der Gaswirtschaft wurden die keramischen Rekuperatorbrenner fuer hoehere Leistungen und Wirkungsgrade weiterentwickelt. Dabei ist es gelungen, keramische Rekuperatoren zu fertigen, die zum einen kostenguenstig hergestellt werden koennen und zum anderen bei einer Prozesstemperatur von 1300 C eine relative Luftvorwaermung von bis zu {epsilon}=0,8 erreichen. Neben der Optimierung der Waermetauscher wurden neue Brennersysteme entwickelt, mit denen die NO{sub x}-Emission reduziert wurde. (orig.)

  10. Development and application of autoignition burner%自动点火燃烧器的研制与应用

    Institute of Scientific and Technical Information of China (English)

    李卫权; 白田增; 吴德; 富玉海; 仪忠建; 任严

    2015-01-01

    钻井、井下作业及油井测试过程中将产生含有较多甲烷、乙烷以及少量易挥发的液态烃及微量的二氧化碳、氮、硫化氢等杂质的伴生气,给安全生产带来重大隐患。为了解决该问题,研发了自动点火燃烧器,该装置用太阳能电池板提供能源,当伴生气压力超过0.1 MPa时,控制系统自动打火点燃液化气,引燃燃烧区内伴生气。现场应用表明,该燃烧器结构设计合理,拆装、运输方便,使用过程中不产生明火,比以往同类手动产品更加安全可靠。%Drilling, downhole operation and oil well testing will generate associated gas which has high content of methane, ethane, small content of volatile liquid hydrocarbon as well as trace amount of carbon dioxide, nitrogen, hydrogen sulifde and other impurities, bringing about major hidden danger to production safety. An autoignition burner is developed, which adopts solar panel to provide energy. When associated gas pressure exceeds 0.1 MPa, control system will enable automatic ignition to ignite liqueifed gas combustion rod, thus to ignite the associated gas in combustion area. It is shown from ifeld application that the burner features reasonable structure design, convenient assembly or disassembly and transportation, and is not easy to generate open ifre, thus the burner is safer and more reliable than previous similar manual products.

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

    KAUST Repository

    Mansour, Morkous S.

    2015-06-30

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

  12. Contribution to the development of the simulation model for the rotary cap burner in the marine steam boiler

    Directory of Open Access Journals (Sweden)

    Dvornik Joško

    2015-01-01

    Full Text Available This paper presents the simulation model for determining the intervals of preventive replacement of the system's components. The application of the Weibull distribution has been proved to be efficient in the approximation of many forms of delay, while numerical integration supported by Simpson formula and Fortran software has been applied to simulate optimum values of the preventive replacement of the components of the rotary cap burner SAACKE, type SKV 60 in the marine steam boiler, on the basis of the available data gathered through the system's exploitation and through empirical assumptions.

  13. Research, development, and testing of a prototype two-stage low-input rate oil burner for variable output heating system applications

    Energy Technology Data Exchange (ETDEWEB)

    Krajewski, R.F.; Butcher, T.A. [Brookhaven National Labs., Upton, NY (United States)

    1997-09-01

    The use of a Two-Stage Fan Atomized Oil Burner (TSFAB) in space and water heating applications will have dramatic advantages in terms of it`s potential for a high Annual Fuel Utilization Efficiency (AFUE) and/or Energy Factor (EF) rating for the equipment. While demonstrations of a single rate burner in an actual application have already yielded sufficient confidence that space and domestic heating loads can be met at a single low firing rate, this represents only a narrow solution to the diverse nature of building space heating and domestic water loads that the industry must address. The mechanical development, proposed control, and testing of the Two-Stage burner is discussed in terms of near term and long term goals.

  14. Migrations et modernité dans les îles Kerkennah

    OpenAIRE

    Ben Hamida, Abdesslem

    2006-01-01

    Les îles Kerkennah, au large de la ville de Sfax, à l’écart des circuits modernes semblent n’être qu’un conservatoire des traditions. Ces îles sont concernées par un important mouvement migratoire dû à un développement de la population et à une économie agricole et de pêche en stagnation. Y a-t-il un lien entre migration et modernité ? La colonisation a eu peu d’influence sur les îles Kerkennah, quelques apports sont à signaler au plan scolaire et sanitaire mais rien d’assez important pour le...

  15. Gradients socioéconomiques du risque cardiovasculaire chez les enfants et les adolescents canadiens

    Directory of Open Access Journals (Sweden)

    Y. Shi

    2016-01-01

    Full Text Available Introduction : Les maladies cardiovasculaires (MCV et leurs facteurs de risque présentent des gradients socioéconomiques clairs chez les adultes canadiens, mais présentent des ambiguïtés chez les enfants. L'objectif de cette étude est de vérifier l'existence ou non de gradients socioéconomiques dans les marqueurs physiologiques du risque de MCV chez les enfants et les adolescents canadiens. Méthodologie : À partir des données transversales combinées de l'Enquête canadienne sur les mesures de la santé 2007-2011, nous avons étudié, chez 2 149 enfants (6 à 11 ans et 2 073 adolescents (12 à 17 ans et selon le sexe, les marqueurs de risque cardiovasculaire suivants : excès de poids (y compris l'obésité, score de capacité aérobique (SCA, pression artérielle (PA, lipides sanguins (totaux, cholestérol LDL et HDL, triglycérides, métabolisme du glucose et protéine C réactive (CRP. Des analyses de régression logistique et de régression linéaire multidimensionnelles ont permis de dégager les tendances relatives au risque cardiovasculaire en fonction de la suffisance du revenu du ménage et du niveau de scolarité des parents, après ajustement en fonction de l'âge et de l'origine ethnique, et après stratification par groupe d'âge et par sexe. Résultats : La prévalence de l'obésité était sensiblement plus élevée chez les jeunes garçons que chez les jeunes filles (prévalence de 18,5 %, intervalle de confiance [IC] à 95 % : 15,6 à 21,5 contre 7,7 %, IC à 95 % : 5,2 à 10,3. Toutefois, des gradients socioéconomiques négatifs ont été observés en ce qui concerne le risque d'adiposité chez les jeunes filles et les adolescentes, et non chez les garçons. Parmi les enfants et les adolescents, les garçons étaient en meilleure condition physique que les filles (SCA moyen de 541, IC à 95 % : 534 à 546 contre 501, IC à 95 % : 498 à 505 chez les enfants; 522, IC à 95 % : 514 à 529 contre 460, IC à 95 % : 454

  16. Prise en charge de l’infection gonococcique chez les adultes et les jeunes

    Science.gov (United States)

    Pogany, Lisa; Romanowski, Barbara; Robinson, Joan; Gale-Rowe, Margaret; Latham-Carmanico, Cathy; Weir, Christine; Wong, Tom

    2015-01-01

    Résumé Objectif Présenter des recommandations sur la prise en charge de l’infection gonococcique chez les adultes et les jeunes. Qualité des données Les recommandations thérapeutiques des lignes directrices canadiennes sur les infections transmissibles sexuellement reposent sur une recherche documentaire de même que sur des catégories de recommandations et des niveaux de qualité de données déterminés par au moins 2 évaluateurs. Les recommandations ont été revues par des pairs et sont en instance d’approbation par le groupe de travail d’experts. Message principal Les nouvelles recommandations portant sur la prise en charge de l’infection gonococcique chez les adultes et les jeunes préconisent les cultures à titre d’outil diagnostique lorsqu’elles sont pratiques, le traitement par antibiothérapie combinée (ceftriaxone associée à l’azithromycine) et le signalement sans délai de tous les cas dont le traitement a échoué aux autorités de santé publique. Conclusion Si elles sont suivies, ces nouvelles recommandations pourraient réduire l’échec thérapeutique, contribuer à une surveillance plus étroite des tendances à la résistance de Neisseria gonorrhoeae aux antibiotiques et contribuer à prévenir la transmission de gonorrhée résistante à plusieurs médicaments.

  17. Independent flameout alarm monitoring system of combustion furnace multi-burners%燃炉多燃烧器独立熄火报警监控系统

    Institute of Scientific and Technical Information of China (English)

    方平; 王一民; 于晓红; 曹旭杰; 何军民

    2014-01-01

    Various combustion furnaces in petrochemical industry use a large number of burners, the normal combustion of burners is related to the safe operation of the combustion furnace. This paper analy-ses how by endoscope-type high temperature probe capture video images of combustion furnace burners, and process images, judge flameout for each burner independently use of computer,when flameout appea-ring in the burner then giving the corresponding alarm. Proved with the accuracy of image analysis soft-ware for judge the flameout of the burner. In the petroleum chemical industry, it will produce far-reac-hing effect for all kinds of fuel, gas-fired boiler risk pre-alarm and safety operation monitoring.%石化各种燃炉内使用的大量燃烧器是否正常燃烧关系到整个燃炉的安全运行。该文分析了如何通过内窥式耐高温探头摄取燃炉内燃烧器视频图像,并使用计算机进行图像处理、分析,对每个燃烧器进行独立的熄火判断,在燃烧器熄火时给出相应的报警。论证了图像分析软件对燃烧器火焰判断的准确性,对石油化工行业各种燃油、燃气锅炉危险预报警等安全运行监控方面将产生深远的影响。

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

    KAUST Repository

    Chung, Yong Ho

    2013-03-01

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

  19. DNS and LES of some engineering flows

    Science.gov (United States)

    Rodi, Wolfgang

    2006-02-01

    In this paper, direct numerical simulations (DNS) and large eddy simulations (LES) of three engineering flows carried out in the author's research group are presented. The first example, simulated both with DNS and LES, is the flow in a low-pressure turbine cascade with wakes passing periodically through the cascade channel. In this situation, the laminar-turbulent transition of the boundary layers on the blade surfaces, which is strongly influenced by the passing wakes, is of special interest. Next, LES of the flow past the Ahmed body is presented, which is a car model with slant back. In spite of the fairly simple geometry, the flow around the model has many features of the complex, fully 3D flow around real cars. The third example, for which LES is presented, is the flow past a surface mounted circular cylinder of height-to-diameter ratio of 2.5. In this case also complex 3D flow develops with interaction of various vortices behind the cylinder. By means of these examples, the paper shows that complex turbulent flows of engineering relevance can be predicted realistically by DNS and LES, albeit at large cost. The methods are particularly suited and superior to RANS methods for situations where unsteadiness like shedding and large-scale structures dominate the flow, and DNS has evolved into an important tool for studying transition mechanisms.

  20. LES of Gas Exchange in IC Engines

    Directory of Open Access Journals (Sweden)

    Mittal V.

    2013-10-01

    Full Text Available As engine technologies become increasingly complex and engines are driven to new operating points, understanding transient phenomena is important to ensure reliable engine operation. Unlike Reynolds Averaged Navier-Stokes (RANS studies that only provide cycle-averaged information, Large Eddy Simulation (LES studies are capable of simulating cycle-to-cycle dynamics. In this work, a finite difference based structured methodology for LES of IC engines is presented. This structured approach allows for an efficient mesh generation process and provides potential for higher order numerical accuracy. An efficient parallel scalable block decomposition is done to overcome the challenges associated with the low ratio of fluid elements to overall mesh elements. The motion of the valves and piston is handled using a dynamic cell blanking approach and the Arbitrary Lagrangian Eulerian (ALE method, respectively. Modified three-dimensional Navier-Stokes Characteristic Boundary Conditions (NSCBC are used in the simulation to prescribe conditions in the manifolds. The accuracy of the simulation framework is validated using various canonical configurations. Flow bench simulations of an axisymmetric configuration and an actual engine geometry are done with the LES methodology. Simulations of the gas exchange in an engine under motored conditions are also performed. Overall, good agreement is obtained with experiments for all the cases. Therefore, this framework can be used for LES of engine simulations. In the future, reactive LES simulations will be performed using this framework.

  1. Experimental Study of the Burners for Liquefied Petroleum Gas%液化石油气烧嘴的试验研究

    Institute of Scientific and Technical Information of China (English)

    王璋保; 陶保国

    2000-01-01

    介绍了LYS2液化石油气烧嘴的结构特点和热工特点。它具有空-煤气混合好、调节比大、助燃空气压力低、可用于冷风或热风、适应性强等特点。%In this paper,the design and thermal characteristics of LYS2 type burner for liquefied petroleum gas are introduced. This kind of burner has good air/gas mixture ,large regulating ratio and low combustion air pressure ,and is applicable to cold or hot air.

  2. Evaluation of Gas Reburning & Low NOx Burners on a Wall Fired Boiler Performance and Economics Report Gas Reburning-Low NOx Burner System Cherokee Station Unit 3 Public Service Company of Colorado

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    1998-07-01

    Under the U.S. Department of Energy's Clean Coal Technology Program (Round 3), a project was completed to demonstrate control of boiler NOX emissions and to a lesser degree, due to coal replacement, SO2 emissions. The project involved combining Gas Reburning with Low NOX Burners (GR-LNB) on a coal-fired electric utility boiler to determine if high levels of NOX reduction (70%) could be achieved. Sponsors of the project included the U.S. Department of Energy, the Gas Research Institute, Public Service Company of Colorado, Colorado Interstate Gas, Electric Power Research Institute, and the Energy and Environmental Research Corporation. The GR-LNB demonstration was performed on Public Service Company of Colorado's (PSCO) Cherokee Unit #3, located in Denver, Colorado. This unit is a 172 MW~ wall-fired boiler that uses Colorado Bituminous, low-sulfur coal. It had a baseline NOX emission level of 0.73 lb/106 Btu using conventional burners. Low NOX burners are designed to yield lower NOX emissions than conventional burners. However, the NOX control achieved with this technique is limited to 30-50%. Also, with LNBs, CO emissions can increase to above acceptable standards. Gas Reburning (GR) is designed to reduce NOX in the flue gas by staged fuel combustion. This technology involves the introduction of natural gas into the hot furnace flue gas stream. When combined, GR and LNBs minimize NOX emissions and maintain acceptable levels of CO emissions. A comprehensive test program was completed, operating over a wide range of boiler conditions. Over 4,000 hours of operation were achieved, providing substantial data. Measurements were taken to quantify reductions in NOX emissions, the impact on boiler equipment and operability and factors influencing costs. The GR-LNB technology achieved good NOX emission reductions and the goals of the project were achieved. Although the performance of the low NOX burners (supplied by others) was less than expected, a NOX reduction of

  3. Les collections de modèles anatomiques équins de Louis Auzoux, une collection à constituer

    OpenAIRE

    Degueurce, Christophe

    2015-01-01

    Le docteur Louis Auzoux (1797-1880) est bien connu pour les mannequins anatomiques de papier qu’il produisit et exporta dans le monde entier. Si les modèles se rapportant à l’homme ont une force esthétique qui leur a donné une visibilité prépondérante, ils sont loin d’être les seuls que le célèbre industriel a conçus et commercialisés ; les animaux, les végétaux et tout particulièrement les fleurs, constituent une autre facette de son art. Mais les modèles dédiés au cheval eurent une importan...

  4. Opposed Jet Burner Extinction Limits: Simple Mixed Hydrocarbon Scramjet Fuels vs Air

    Science.gov (United States)

    Pellett, Gerald L.; Vaden, Sarah N.; Wilson, Lloyd G.

    2007-01-01

    Opposed Jet Burner tools have been used extensively by the authors to measure Flame Strength (FS) of laminar non-premixed H2 air and simple hydrocarbon (HC) air counterflow diffusion flames at 1-atm. FS represents a strain-induced extinction limit based on air jet velocity. This paper follows AIAA-2006-5223, and provides new HC air FSs for global testing of chemical kinetics, and for characterizing idealized flameholding potentials during early scramjet-like combustion. Previous FS data included six HCs, pure and N2-diluted; and three HC-diluted H2 fuels, where FS decayed very nonlinearly as HC was added to H2, due to H-atom scavenging. This study presents FSs on mixtures of (candidate surrogate) HCs, some with very high FS ethylene. Included are four binary gaseous systems at 300 K, and a hot ternary system at approx. 600 K. The binaries are methane + ethylene, ethane + ethylene, methane + ethane, and methane + propylene. The first three also form two ternary systems. The hot ternary includes both 10.8 and 21.3 mole % vaporized n-heptane and full ranges of methane + ethylene. Normalized FS data provide accurate means of (1) validating, globally, chemical kinetics for extinction of non-premixed flames, and (2) estimating (scaling by HC) the loss of incipient flameholding in scramjet combustors. The n-heptane is part of a proposed baseline simulant (10 mole % with 30% methane + 60% ethylene) that mimics the ignition of endothermically cracked JP-7 like kerosene fuel, as suggested by Colket and Spadaccini in 2001 in their shock tube Scramjet Fuels Autoignition Study. Presently, we use FS to gauge idealized flameholding, and define HC surrogates. First, FS was characterized for hot nheptane + methane + ethylene; then a hot 36 mole % methane + 64% ethylene surrogate was defined that mimics FS of the baseline simulant system. A similar hot ethane + ethylene surrogate can also be defined, but it has lower vapor pressure at 300 K, and thus exhibits reduced gaseous

  5. Use of freeze-casting in advanced burner reactor fuel design

    Energy Technology Data Exchange (ETDEWEB)

    Lang, A. L.; Yablinsky, C. A.; Allen, T. R. [Dept. of Engineering Physics, Univ. of Wisconsin Madison, 1500 Engineering Drive, Madison, WI 53711 (United States); Burger, J.; Hunger, P. M.; Wegst, U. G. K. [Thayer School of Engineering, Dartmouth College, 8000 Cummings Hall, Hanover, NH 03755 (United States)

    2012-07-01

    This paper will detail the modeling of a fast reactor with fuel pins created using a freeze-casting process. Freeze-casting is a method of creating an inert scaffold within a fuel pin. The scaffold is created using a directional solidification process and results in open porosity for emplacement of fuel, with pores ranging in size from 300 microns to 500 microns in diameter. These pores allow multiple fuel types and enrichments to be loaded into one fuel pin. Also, each pore could be filled with varying amounts of fuel to allow for the specific volume of fission gases created by that fuel type. Currently fast reactors, including advanced burner reactors (ABR's), are not economically feasible due to the high cost of operating the reactors and of reprocessing the fuel. However, if the fuel could be very precisely placed, such as within a freeze-cast scaffold, this could increase fuel performance and result in a valid design with a much lower cost per megawatt. In addition to competitive costs, freeze-cast fuel would also allow for selective breeding or burning of actinides within specific locations in fast reactors. For example, fast flux peak locations could be utilized on a minute scale to target specific actinides for transmutation. Freeze-cast fuel is extremely flexible and has great potential in a variety of applications. This paper performs initial modeling of freeze-cast fuel, with the generic fast reactor parameters for this model based on EBR-II. The core has an assumed power of 62.5 MWt. The neutronics code used was Monte Carlo N-Particle (MCNP5) transport code. Uniform pore sizes were used in increments of 100 microns. Two different freeze-cast scaffold materials were used: ceramic (MgO-ZrO{sub 2}) and steel (SS316L). Separate models were needed for each material because the freeze-cast ceramic and metal scaffolds have different structural characteristics and overall porosities. Basic criticality results were compiled for the various models

  6. Herder et les Lumières

    OpenAIRE

    2011-01-01

    Si Herder construit sa pensée en s’opposant à l’hégémonie voltairienne sur l’Allemagne, c’est aussi en fréquentant très précisément Jean-Jacques Rousseau ou encore Helvétius et d’Alembert, les écrits de Hume ou les chants d’Ossian, qu’il conduit sa réflexion à sa pleine maturité. Les philosophies française et écossaise jouent dans son évolution un rôle décisif. Des chercheurs européens ont réuni leurs efforts pour souligner la dimension cosmopolite de Herder. L’élargissement géographique de l...

  7. Les actionnaires salariés

    OpenAIRE

    Philippe Desbrières

    2002-01-01

    L'actionnariat est l'une des formules de participation financière utilisées pour stimuler les efforts des salariés. Il leur permet de constituer un portefeuille de valeurs mobilières et d'acquérir, souvent dans des conditions avantageuses, des actions de la société qui les emploie. Mais il conduit les salariés à y assumer un double statut : d'apporteur de capital humain d'une part, d'apporteur de ressources financières d'autre part. Se pose alors de manière accrue le problème de la sauvegarde...

  8. Les consequences de Tchernobyl et la sociopathologie

    Directory of Open Access Journals (Sweden)

    Laurent Bocéno

    2006-06-01

    Full Text Available Dans la situation de post-catastrophe aux alentours de Tchernobyl, la vie quotidienne est une correspondance constante entre l'institué et le vécu qui sont souvent analysés séparément. Avec l'approche par les sociopathologies, il est possible d'examiner le social entré dans le corps comme le résultat de l'intériorisation en nous, d'archétypes sociaux d'une part et d'autre part, de situations incorporées. Les sociopathologies sont liées aux formes d'institutionnalisation dont le sens est souvent ignoré par les personnes qui y sont confrontées.

  9. Les traditions céramiques dogon

    OpenAIRE

    Gallay, Alain; Kalapo, Y.; Guindo, E.

    2006-01-01

    Le Pays dogon est réputé pour ses traditions artisanales. Depuis une dizaine d'années, nous nous sommes donnés pour tâche d'étudier l'artisanat de la poterie, aujourd'hui en cours de disparition sous la pression de la diffusion de la vaisselle métallique d'origine industrielle, et de dresser un tableau complet des traditions céramiques du Pays dogon. Notre intérêt s'est porté plus particulièrement sur les relations existant entre les différentes traditions et les principales communautés dogon...

  10. Les métamorphoses du pouvoir

    OpenAIRE

    Adler, Alfred

    2004-01-01

    On sait que la sorcellerie en Afrique peut s'exercer du faible au fort ou l'inverse. Les situations qui sont ici analysées sont celles où les rois ou les chefs sont expressément désignés comme sorciers, soit qu'ils le deviennent du fait même de leur investiture, soit qu'il leur ait fallu le devenir pour accéder au pouvoir et le conserver face à des rivaux usant des mêmes moyens. Quoi qu'il en soit, un roi-sorcier offre une figure paradoxale du pouvoir, et cela doublement : garant de l'...

  11. Retour sur les images d’organisations

    OpenAIRE

    Laborde, Aurélie; Mahy, Isabelle; Soubiale, Nadège

    2011-01-01

    Depuis les années 1970, les sciences de gestion et la littérature managériale se sont emparées du vocable d’image pour traduire un ensemble de conduites et de stratégies éparses des organisations soumises aux aléas de la concurrence et de la dérégulation des marchés. Construite et projetée par l’organisation, l’image se fait image de marque, communication institutionnelle et corporative, stratégie de valorisation de l’image des entreprises. Perçue et interprétée par les acteurs et l’environn...

  12. Chapitre II. Les madréporaires

    OpenAIRE

    Service mixte de surveillance radiologique et biologique,

    2013-01-01

    On emploie couramment le terme de corail pour désigner les organismes sécrétant le squelette calcaire blanc que l’on observe sur les récifs. A vrai dire, employé dans ce sens, le terme corail est impropre. Le véritable corail est le corail rouge : Corallium rubrum vivant en Méditerranée et au Japon et dont le squelette branchu sert à la fabrication des bracelets et des colliers. Le corail des récifs est désigné par les naturalistes sous le terme de Madréporaires ou de Scléractiniaires. Dans l...

  13. Deux livres pour penser les sciences

    Directory of Open Access Journals (Sweden)

    Laurent Matthey

    2008-06-01

    Full Text Available Qu’est-ce que la science ? Existe-t-il, entre les différentes disciplines, des éléments qui permettent de parler d’une science au singulier ? Ou le pluriel est-il de rigueur, l’éclatement des traditions et habitudes de recherche nécessitant que l’on parle plutôt de sciences ? Quel est le rapport que la pratique scientifique entretient avec le réel ? Les théories que livrent les chercheurs décrivent-elles un monde externe ? Ne font-elles que cela ? On bien faut-il voir ces théories comme des «...

  14. Emissions and properties of Bio-oil and Natural Gas Co-combustion in a Pilot Stabilised Swirl Burner

    Science.gov (United States)

    Kowalewski, Dylan

    Fast pyrolysis oil, or bio-oil, has been investigated to replace traditional fossil fuels in industrial burners. However, flame stability is a challenge due to its high water content. In order to address its instability, bio-oil was co-fired with natural gas in a lab scale 10kW swirl burner at energy ratios from 0% bio-oil to 80% bio-oil. To evaluate the combustion, flame shape, exhaust and particulate emissions, temperatures, as well as infrared emission were monitored. As the bio-oil energy fraction increased, NO emissions increased due to the nitrogen content of bio-oil. CO and particulate emissions increased likely due to carbonaceous residue exiting the combustion zone. Unburnt Hydrocarbon (UHC) emissions increased rapidly as combustion became poor at 60-80% bio-oil energy. The temperature and infrared output decreased with more bio-oil energy. The natural gas proved to be effective at anchoring the bio-oil flame to the nozzle, decreasing instances of extinction or blowout.

  15. Method of Comparative Analysis of Highly Dispersed Condensed Fuel Combustion Efficiency in Arbitrary Geometry Solid Propellant Ramjet Burners

    Directory of Open Access Journals (Sweden)

    A. V. Voroneckii

    2016-01-01

    Full Text Available The paper deals with various theoretical approaches to the mathematical modeling of the operating process in solid propellant ramjets (SPRJ that use highly metalized solid propellant. It introduces a new method (combustion operating law method that allows us to carry out comparative analysis of combustion efficiency in SPRJ arbitrary geometry ram-burners (RB when there is no accurate information on the combustion law of condensed fuel particles. To illustrate an application of the proposed method, mathematical modeling of the operating process was conducted for three SPRJ ram-burners with three different air intakes (AI, for which distribution fields of main parameters of gas and fuel particles have been obtained. Most complete combustion of fuel particles and the lowest level of particles buildup are registered for RB180 (180 degree angle between AIs. The results of a comparative analysis show that the relative (compared to RB180 efficiency of the particle burning process equals 0.64 and 0.6, respectively, for RB90 (90 degree angle between AIs and RB60 (60 degree angle between AIs. The proposed method may be applied to solve the most difficult problems of mathematical modeling when the optimization development of the solid propellant and ramjet structure are fulfilled simultaneously, i.e. when designers do not have the complete information about the combustion law of the condensed fuel particles.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-15

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

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

    Directory of Open Access Journals (Sweden)

    Kanokkarn Jirakulsomchok

    2017-08-01

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

  18. Peuplement et environnement dans les Guyanes

    OpenAIRE

    Versteeg, Aad

    2013-01-01

    Les chasseurs (paléo-indiens) Les premiers habitants du Nord de l’Amérique du Sud étaient des chasseurs de mégafaune au Venezuela occidental, à l’ouest du Plateau des Guyanes. Ils appartiennent à la culture El Jobo, datée entre 14000 et 12000 BP. Deux autres cultures paléo-indiennes similaires lui correspondent : la culture Canaima du haut Caroni au Venezuela oriental, et la culture Sipaliwini dans le sud du Surinam (Boomert, 1980). Ces trois cultures ont notamment en commun l’utilisation de ...

  19. Les TIC, un monde à partager

    OpenAIRE

    Daignault, Jacques

    2005-01-01

    L'Association québécoise des utilisateurs de l'ordinateur au primaire-secondaire (AQUOPS) a tenu son colloque annuel les 22, 23 et 24 mars 2005 sur le thème Les TIC, un monde à partager. Le thème mérite une réflexion invitant à la participation et à la mise en place d'un forum très large sur la protection de la connaissance comme bien commun et universel.

  20. Les transformations du jeûne chez les chrétiens d'Orient

    Directory of Open Access Journals (Sweden)

    Bernard Heyberger

    2006-11-01

    Full Text Available Dans le christianisme, les règles du jeûne et de l’abstinence sont extrêmement complexes, dans leur rythme annuel et dans leurs prescriptions alimentaires, ce qui les distingue nettement de la pratique musulmane. C’est peut-être davantage dans l’anthropologie sous-jacente qu’on pourrait déterminer des conceptions communes aux deux religions. Ces règles se sont élaborées progressivement, entre le ive et le xiiie siècle, différenciant les Églises orientales de l’Église romaine, mais introduisant aussi des distinctions entre Églises orientales rivales. Il est assez difficile de se former une opinion claire sur les prescriptions et sur leur application concrète dans chaque groupe de chrétiens.À partir du xviie siècle, les Églises orientales se voient interrogées à propos de leurs pratiques en matière de jeûne et d’abstinence par les missionnaires et les érudits latins, et sommées de définir des règles strictes et définitives. En même temps, l’introduction des références du catholicisme latin fait perdre le sens du jeûne comme oeuvre collective, au profit d’une ascèse personnelle et intériorisée, centrée sur la pratique des sacrements. Les transformations du jeûne deviennent alors symptôme de la « modernisation » en cours chez les chrétiens orientaux.

  1. Penser les métropoles pour les « individus » ?

    Directory of Open Access Journals (Sweden)

    Marc Dumont

    2006-03-01

    Full Text Available Les instruments dont on dispose aujourd’hui pour décrire et expliquer les réalités métropolitaines contemporaines ne sont pas entièrement satisfaisants : ils ne permettent pas toujours d’identifier les vraies questions qui se présentent à ceux qui produisent la ville. Partant de ce constat, le sociologue Alain Bourdin synthétise dans son nouvel essai des réflexions issues de sa pratique de recherche et de dialogue avec le monde des institutions, pour y proposer une lecture de la ...

  2. Les écrits comme supports de raisonnement dans les exploitations d'élevage

    OpenAIRE

    Havet, Alain; Joly, Nathalie; Cochet, A.

    2005-01-01

    Nombre d’initiatives propose aux agriculteurs des outils, souvent informatiques, pour faciliter la fourniture à des tiers d’une part grandissante d’information, le plus souvent sans tenir compte des notations déjà mises en place dans les exploitations. Notre objectif est ici de repositionner l’agriculteur comme principal bénéficiaire d’un système d’information dont il aurait la pleine maîtrise. Nous avons choisi de nous intéresser au lien entre les raisonnements et les écrits disponibles pour...

  3. Les quarante heures dans les mines de charbon sous le Front populaire

    OpenAIRE

    Philippe, Aurélie

    2015-01-01

    Le principe de la semaine de quarante heures, diminution du temps de travail sans diminution des salaires, apparaît dans les travaux de l’O.I.T. (Organisation internationale du Travail) comme une solution à la crise économique des années 1930. Le Front populaire reprend cette mesure et promulgue la loi sur la semaine de quarante heures le 21 juin 1936. L’étude de son application, au jour le jour, dans un secteur et une région spécifique, les mines de charbon du Nord-Pas-de-Calais, nuance les ...

  4. Thermally accurate LES of the stability-emission performance of staged gas-turbine combustion; Simulation aux grandes echelles de la combustion etagee dans les turbines a gaz et son interaction stabilite-polluants-thermique

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, P.

    2005-06-15

    Modern gas turbines use turbulent lean partially premixed combustion in order to minimise nitrous oxide (NO{sub X}) emissions while ensuring flashback safety. The Large-Eddy Simulation (LES) of such a device is the goal of this work. Focus is laid on correctly predicting the NO{sub X} emissions, which are influenced by four factors: heat transfer, mixing quality, combustion modelling and thermo-acoustic stability. As NO{sub X} reaction rates are strongly influenced by temperature, heat transfer by radiation and convection is included. Radiation is predicted by a model, which assumes that the gases are optically thin. Convective heat transfer is included via a newly developed and validated wall-function approach based on the logarithmic law of the wall for temperature. An optimised 2-step reduced chemical reaction scheme for lean methane combustion is presented. This scheme is used for the LES in conjunction with an additional third reaction, fitted to produce the same NO{sub X} reaction rates as in the complete reaction mechanism. Turbulence is accounted for with the thickened flame model in a form, which is optimised for changing equivalence ratios and mesh-resolutions. Mixing is essential not only for predicting flame stabilisation, but also for pollutant emissions as NO{sub X} reaction rates depend exponentially on equivalence ratio. Therefore the full burner geometry, including 16 fuel injections is resolved in LES. Additionally, effusion cooling and film cooling is accounted for in a simplified manner. The non-reacting flow is extensively validated with experimental results. As mixture-fraction fluctuations do not only arise from turbulence, but also from thermo-acoustic instabilities, care was taken to provide acoustic boundary conditions that come close to reality. The resulting LES shows a strong thermo-acoustic instability, comparing well with experimental observations. By making the boundaries completely anechoic it is shown that when the instability

  5. Les paradoxes de la matière

    CERN Document Server

    2013-01-01

    Si nous devons la multitude d’appareils numériques actuels à l’électronique, celle-ci atteint ses limites. Comment les dépasser ? En explorant les propriétés spectaculaires de la matière ! Et les candidats au remplacement de l’électronique sont nombreux : oxytronique, spintronique, plasmonique, magnonique, graphène... Nous réservant aussi bien d’autres surprises - tels les capes d’invisibilité, les plastiques conducteurs, les polymères autocicatrisants, les protections antisismiques, etc - les études sur la matière n’ont pas fini de nous étonner.

  6. Partial conversion of hydrocarbons to syngas and hydrogen in volumetric radiation burners as a prospective way to enhance the performance characteristics of power engines

    Science.gov (United States)

    Arutyunov, V. S.; Shmelev, V. M.; Shapovalova, O. V.; Rakhmetov, A. N.; Strekova, L. N.

    2013-03-01

    New type of syngas generator based on the partial conversion of natural gas (methane) or heavier hydrocarbons in volumetric permeable matrix burners in the conditions of locked infrared (IR) radiation is suggested as a high-productive, adaptable, and rather simple way of syngas and hydrogen production for various low-scale applications including enhancing the performance characteristics of power engines.

  7. 枪式辐射管燃气燃烧器的设计%Gun Type Gas Burners for Radiating Tube

    Institute of Scientific and Technical Information of China (English)

    冯华仲

    2000-01-01

    This article introduces a gun type of gas burners for radiating tube and a method of designing combustion unit for radiating rube.%介绍一种枪式辐射管燃气燃烧器及其燃烧头的设计。

  8. Study on the Effect of the Side Secondary Air Velocity on the Aerodynamic Field in a Tangentially Fired Furnace with HBC—SSA Burner

    Institute of Scientific and Technical Information of China (English)

    ZhuTong; SunShaozeng; 等

    1999-01-01

    The present paper has compared a group of furnace aerodynamic fields at different velocities of side secondary air(SSA) in a test model of 420t/h utility boiler,applying Horizontal Bias Conbustion Pulverized Coal Burner with Side Secondary AIr(HBC-SSA Burner).Experimental results show that,when the ram pressure ratio of side secondary air(SSA) to primary air(PA) ρ2sv232/ρ1v12)is between 1.0-2.4,the furnace aerodynamic field only varies slightly.The relative rotational diameters(φ/L)in the burner domain are moderate and the furnace is in good fullness.Whenρ2s v232/ρ1v12 is beyond4,φ/L is so large that the stream sweeps water-cooled wall and rotateds strongly in the furnace.Therefore,slagging and high temperature corrosion of tube metal will be formed on the water-cooled wall in actual operation.This investigation provides the basis for the application of this new type burner.In addition,numerical simulations are conducted,and some defects in the numerical simulation are also pointed out and analyzed in this paper.

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

    Science.gov (United States)

    Hladky, Paul W.

    2009-01-01

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

  10. Experimental characterization of a radiant porous burner for low temperatures using natural gas; Caracterizacao experimental de um queimador poroso radiante a gas natural para baixas temperaturas

    Energy Technology Data Exchange (ETDEWEB)

    Catapan, Rafael C.; Hissanaga, Newton Junior; Pereira, Fernando M.; Oliveira Junior, Amir A.M. de [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica; Serfaty, Ricardo [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES); Freire, Luiz G.M. [PETROBRAS - RedeGasEnergia, RJ (Brazil)

    2004-07-01

    This article describes the experimental characterization of a radiant porous burner for temperatures between 500 deg C and 900 deg C. These low temperature radiant burners can be used in many practical applications as drying of paper and wood, plastic coating, food cooking and ambient heating. Two different configurations of silicon carbide porous ceramic foams were tested: one with a radian reflecting region (RRR) at the outlet and another without this region. Both configurations were able to sustain the reaction with equivalent ratio under 0,35. The configuration with a reflecting region was able to sustain flames with a minimum power of 60 kW/m{sup 2} and the other configuration with 100 W/m{sup 2}.The configuration with the RRR reached minimum superficial temperatures about 100 deg C lower than the other one. These results show that the reflecting region increases the heat recirculation inside the porous burner. The radiant efficiency varied from 20% to 35% for both burners. (author)

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

    NARCIS (Netherlands)

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

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

  12. Les Robertson, CERN's LCG project manager

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    "The LCG will provide a vital test-bed for the new Grid computing technologies that are set to revolutionise the way scientists use the world's computing resources in areas ranging from fundamental research to medical diagnosis," said Les Robertson, CERN's LCG project manager. The Grid is a new method of sharing processing power between computers in centres around the world.

  13. Maintenance sur les infrastructures de surface

    CERN Document Server

    Chevret, P

    2000-01-01

    L'objet de ce document est de dresser le bilan de l'activité du Groupe Technical Facilities Management dans le domaine de la maintenance. Ce bilan couvre les activités techniques du génie civil, du chauffage-climatisation et de l'électricité, s'appliquant dans une large majorité au seul secteur tertiaire, tant sur le plan préventif que correctif. Les principaux paramètres indicateurs de l'activité sont situés dans leur évolution au cours des dernières années. Les auteurs abordent également les principaux projets complémentaires de maintenance, qui sont conduits pour maintenir l'état du patrimoine en dépit des restrictions budgétaires, faire face aux problèmes d'obsolescence, de défaillances récurrentes sur certains matériels, et satisfaire aux normes de sécurité. L'incidence positive de ces actions sur le nombre d'interventions de maintenance corrective est également montrée. Enfin, des perspectives de progrès sont dégagées, visant à une gestion davantage prévisionnelle de la ma...

  14. LES TUMEURS MALIGNES DE LA PAROTIDE

    African Journals Online (AJOL)

    18 juin 2007 ... cancers parotidiens opérés dans notre service entre 1994 et 2006, incluant les ... dans 7 cas, un trismus dans un cas, des otalgies dans 2 cas. .... gnant salivary gland tumors by fast neutron radiotherapy. Int J Radiat ... 18-Fordice J, El-naggar; Adenoid cystic carcinoma of the head and neck : pre- dictors of ...

  15. Les communes bretonnes sur le Web

    Directory of Open Access Journals (Sweden)

    Hélène Martin-Brelot

    2015-10-01

    Full Text Available Dans un contexte de montée en puissance des usages d’Internet d’une part, et d’incertitude territoriale d’autre part, l’hypothèse principale de cette étude est que le Web modifie la portée spatiale des organisations publiques, en offrant notamment un nouveau cadre pour exprimer des relations territoriales variées. L’exploration des hyperliens de près de 400 sites de communes du Morbihan et du Finistère permet tout d’abord d’en évaluer la richesse de contenu (images, vidéos… et d’ouverture vers l’extérieur (liens externes, Facebook, etc.. Si les sites les plus fournis et ouverts tendent à appartenir aux communes les plus peuplées, l’examen des relations entre ces sites montre que de très petites communes peuvent occuper des positions centrales dans l’espace virtuel. Des différences de configurations entre les graphes de chaque département sont également identifiées.

  16. Les oniriques Fleurs bleues de Raymond Queneau

    Directory of Open Access Journals (Sweden)

    Primož Vitez

    2012-12-01

    Full Text Available Dans Les fleurs bleues (1965 de Raymond Queneau, le narrateur fait couler deux histoires parallèles qui se terminent dans lʼunité du présent énonciatif.Lʼeffet contrastant de ce double récit, habité dʼun côté par le DucdʼAuge et de lʼautre par un certain Cidrolin, deux facettes dʼun seul personnage, se fonde sur un principe onirique, déclenché au moment quand le Duc dʼAuge sʼendort; dans son rêve se déploie lʼhistoire de Cidrolin qui finitpar sʼendormir à son tour - et voilà le lecteur replongé dans les aventures du Duc. Ce que lʼauteur développe par ses astuces narratives, cʼest la pluralité du réel, ce sont les parallélismes invisibles, cʼest la promesse dʼune perspective existentielle, cʼest la fécondité de lʼironie. À travers la variation de ce qui apparamment est ordinaire, Queneau démontre une dimension extraordinaire de lʼinvention littéraire.

  17. Où sont passés les trous noirs primordiaux?

    CERN Multimedia

    Barrau, A

    2003-01-01

    L'existence de minuscules trous noirs est théoriquement possible mais, toutes les expériences se sont soldées par un échec. Les physiciens son toujours optimistes: puisqu'ils les ont pensés, pourquoi n'existeraient-ils pas?" (6 pages).

  18. LES based POD analysis of Jet in Cross Flow

    DEFF Research Database (Denmark)

    Cavar, Dalibor; Meyer, Knud Erik; Jakirlic, S.

    2010-01-01

    The paper presents results of a POD investigation of the LES based numerical simulation of the jet-in-crossflow (JICF) flowfield. LES results are firstly compared to the pointwise LDA measurements. 2D POD analysis is then used as a comparison basis for PIV measurements and LES, and finally 3D POD...

  19. Les nouveaux espaces de l'industrie en France

    Directory of Open Access Journals (Sweden)

    Roger BRUNET

    1986-03-01

    Full Text Available Des cartes à un niveau d'analyse nouveau, et la représentation modélisée des structures et tendances fondamentales de l'espace industriel français, permettent de discerner les situations «porteuses» pour l'avenir des entreprises, et les conditions dans lesquelles se font les changements.

  20. Les livres pairs d’Alfred Jarry

    Directory of Open Access Journals (Sweden)

    Julien Schuh

    2008-10-01

    Full Text Available Dans les Gestes et opinions du Dr Faustroll, pataphysicien, Alfred Jarry décrit une bibliothèque idéale, composée de 27 ouvrages qu’il nomme mystérieusement des « livres pairs ». Dans cette liste, on trouve aussi bien des œuvres canoniques du symbolisme (Mallarmé, Verlaine, Poe traduit par Baudelaire, des titres des amis de Jarry et des piliers des revues de l’époque (Rachilde, Gustave Kahn, Léon Bloy, que des ouvrages que l’on assimile davantage aux lectures enfantines (un conte de Marceline Desbordes-Valmore, les Mille et une Nuits, le théâtre de Florian ou des textes hors-catégorie (l’œuvre de Rabelais, l’évangile de Luc, les Chants de Maldoror. Beaucoup de critiques se sont interrogés sur la notion de « parité », sur l’égalité supposée entre ces ouvrages n’appartenant pas aux mêmes catégories littéraires. Mais l’intérêt de cette liste n’est pas de fournir un classement, ou d’affirmer l’équivalence de toutes les formes textuelles, comme on l’analyse souvent, en faisant de Jarry un chantre du nihilisme qui chercherait à pervertir les hiérarchies littéraires pour montrer la vacuité du sens. Au contraire, en faisant débuter le Faustroll par une liste d’ouvrages, Jarry met en place les conditions de réception de son texte, dans une posture très littéraire. L’espace délimité par la liste des auteurs pairs fonctionne comme un portrait spirituel de Jarry-littérateur, et livre le contexte selon lequel son discours doit être reçu. La bibliothèque du Dr Faustroll fixe les références que le lecteur pourra voir convoquer dans le texte, et circonscrit l’espace littéraire dans lequel peut fonctionner cet ouvrage.

  1. Des broussailles dans les prairies alpines

    Directory of Open Access Journals (Sweden)

    Olivier Camacho

    2009-03-01

    Full Text Available Landscape closing due to the decline in agricultural activity is considered to be a major problem in the Alps. Abondance Valley provides a good example of this phenomenon and is also representative of a paradox commonly found in the Northern French Alps: the mountainsides and alpine pastures are still used, whereas they are becoming increasingly afforested. Environmental conditions play a major role in the localisation of agricultural land uses, but they are not sufficient to explain why pastures still in use are being invaded by shrub. Even if cutting makes it possible to effectively control the encroachment by woody species, this is not true for uncut pastures where grazing is not able to keep up with grass production. This situation is repeated every year and is the likely cause of the colonisation by woody species. To ensure their forage system and to simplify their work, farmers tend to establish grazing units that are oversized in relation to the needs of their animals. They implement compensatory practices that consist of mechanical maintenance as a complement to grazing to limit the dynamics of woody species. These labour-intensive practices are not used on all of the pastures. The analysis of farmers’ practices by agronomists is therefore a useful complement to studies of physical and socio-economic environments, at the level of the grazed field as well as at that of the valley as a whole.La dégradation des paysages par suite du recul de l’activité agricole est considérée comme un enjeu majeur dans les Alpes. La vallée d’Abondance illustre bien ce phénomène de fermeture de l’espace mais elle est en outre représentative d’un paradoxe assez répandu dans les Alpes du nord françaises : les versants et les alpages sont encore exploités et pourtant ils se boisent progressivement. Les conditions de milieux jouent un rôle majeur sur la localisation des usages agricoles de l'espace, mais elles ne peuvent pas suffire pour

  2. HT-NR3旋流燃烧器冷态试验%Cold-state test study on an HT-NR3 swirl burner

    Institute of Scientific and Technical Information of China (English)

    成汭珅; 张广才; 陈国辉; 周科; 王一坤; 解冰

    2014-01-01

    针对采用 HT-NR3旋流燃烧器锅炉存在的水冷壁以及侧墙高温腐蚀、燃烧器喷口烧损等问题,将燃烧器扩口角度从45°改为35°,并对这2种不同扩口角度的 HT-NR3燃烧器进行冷态试验研究。结果表明,与采用45°扩口的燃烧器相比,采用35°扩口燃烧器的回流区和出口气流扩展角均较小,外二次风旋流叶片的调节范围更广,对煤种的适应性更强,可有效防止燃烧器喷口结渣和烧毁,提高燃烧的稳定性,有利于降低N Ox 的排放。%To solve such problems as high temperature corrosion and burner outlet burnt occurred in water wall and furnace side wall in boilers equipped with HT-NR3 swirl burners,the burner flaring angle was changed from 45°to 35°,and cold-state tests were carried out on the HT-NR3 swirl burner with the above two burner flaring angles.The results show that,compared with the burner with flaring angle of 45°,the one with that of 35°has smaller recirculation zone and outlet gas spread angle,wider regulation range of outer secondary air swirl blade and stronger adaptability for coal type.Therefore,it can prevent the burner outlet from slagging and being burnt effectively,which improved the stability of the combustion and was helpful to the reduction of NOx emission.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Sunghwan; Kim, Sang Ji [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

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

  4. Faut-il brûler les dictionnaires ? Ou comment les ressources numériques ont révolutionné les recherches en morphologie

    Directory of Open Access Journals (Sweden)

    Namer Fiammetta

    2012-07-01

    Full Text Available Pour mener leurs études, les morphologues, et, singulièrement parmi eux, ceux qui traitent du lexique construit, sont pris entre deux tensions : utiliser les données issues des dictionnaires, réputées fiables parce que passées au travers du crible de l’institutionnalisation, ou se fonder sur des données authentiques, produites dans des situations écologiques. Bien qu’inspirant encore de la défiance, le Web devient alors la ressource par excellence. Les ressources numérisées telles que les archives de journaux ou les bases de données de textes littéraires constituent un moyen terme entre ces deux pratiques : elles permettent d’effectuer des recherches basées sur l’usage, tout en offrant la garantie d’une certaine tenue linguistique de la part des scripteurs, la plupart du temps identifiables. Dans cette communication, nous nous demanderons si les dictionnaires méritent la confiance que continuent de leur octroyer les morphologues ou, plus exactement, si une morphologie qui puise ses données dans les seuls dictionnaires peut encore avoir cours au 21e siècle. Pour engager cette discussion, nous commencerons par poser la question de l’existence, pour un lexème construit. Nous exposerons ensuite ce que constitue une morphologie basée sur l’usage, puis donnerons un aperçu des types de recherches que permettent de réaliser les ressources non dictionnairiques. La conclusion sera que, si les dictionnaires continuent d'avoir droit de cité dans la panoplie du morphologue, une morphologie uniquement basée sur les données qu'ils contiennent passerait outre de nombreuses recherches, plus fructueuses les unes que les autres.

  5. Notice sur les Lépidoptères des îles Natuna

    NARCIS (Netherlands)

    Snellen, P.C.T.

    1895-01-01

    Mr. Ritsema, Conservateur de la collection d’Insectes du Musée de Leyde, ayant reçu quelques Lépidoptères que Mr. A. L. van Hasselt, Résident de Riouw et de ses dépendances, avait recueillis aux îles Natuna, me pria d’en dresser la liste, parce que jusqu’ici rien n’avait été publié sur les insectes

  6. Note sur les fondements des postcolonial studies

    Directory of Open Access Journals (Sweden)

    Béatrice Collignon

    2008-03-01

    Full Text Available Longtemps absent dans les sciences sociales françaises, le terme "postcolonial" apparaît de plus en plus fréquemment dans les publications et programmes de rencontres, sous l'impulsion des débats autour de l'héritage de la colonisation et des "indigènes de la République". Dans ce contexte, cette note présente les principaux traits qui fondent des postcolonial studies telles qu'elles se sont développées dans le monde anglo-saxon depuis une vingtaine d'années. Cette mise au point, à l'usage des géographes entre autres, vise à clarifier les échanges en montrant le décalage entre le post-colonial français et les postcolonial studies.Long ignored by French social sciences, the term "postcolonial" has recently become popular in academic literature and meetings, in relation to the political debate about colonial legacy and 2nd and 3rd immigrants generations (the so-called "indigènes de la République". Yet, although the term is the same ("postcolonial", the meaning it is usually given in France by those who qualify their work as such is quite different from the one it has in the anglo world. In this context, this note aims at clarifying the situation for French geographers and others by presenting briefly some of the main aspects of postcolonial theory.

  7. Aerothermodynamic cycle analysis of a dual-spool, separate-exhaust turbofan engine with an interstage turbine burner

    Science.gov (United States)

    Liew, Ka Heng

    This study focuses on a specific engine, i.e., a dual-spool, separate-flow turbofan engine with an Interstage Turbine Burner (ITB). This conventional turbofan engine has been modified to include a secondary isobaric burner, i.e., ITB, in a transition duct between the high-pressure turbine and the low-pressure turbine. The preliminary design phase for this modified engine starts with the aerothermodynamics cycle analysis is consisting of parametric (i.e., on-design) and performance ( i.e., off-design) cycle analyses. In parametric analysis, the modified engine performance parameters are evaluated and compared with baseline engine in terms of design limitation (maximum turbine inlet temperature), flight conditions (such as flight Mach condition, ambient temperature and pressure), and design choices (such as compressor pressure ratio, fan pressure ratio, fan bypass ratio etc.). A turbine cooling model is also included to account for the effect of cooling air on engine performance. The results from the on-design analysis confirmed the advantage of using ITB, i.e., higher specific thrust with small increases in thrust specific fuel consumption, less cooling air, and less NOx production, provided that the main burner exit temperature and ITB exit temperature are properly specified. It is also important to identify the critical ITB temperature, beyond which the ITB is turned off and has no advantage at all. With the encouraging results from parametric cycle analysis, a detailed performance cycle analysis of the identical engine is also conducted for steady-state engine performance prediction. The results from off-design cycle analysis show that the ITB engine at full throttle setting has enhanced performance over baseline engine. Furthermore, ITB engine operating at partial throttle settings will exhibit higher thrust at lower specific fuel consumption and improved thermal efficiency over the baseline engine. A mission analysis is also presented to predict the fuel

  8. First archeointensity determinations on Maya incense burners from Palenque temples, Mexico: New data to constrain the Mesoamerica secular variation curve

    Science.gov (United States)

    Fanjat, G.; Camps, P.; Alva Valdivia, L. M.; Sougrati, M. T.; Cuevas-Garcia, M.; Perrin, M.

    2013-02-01

    We present archeointensity data carried out on pieces of incense burners from the ancient Maya city of Palenque, Chiapas, Mexico, covering much of the Mesoamerican Classic period, from A.D. 400 to A.D. 850. We worked on pieces from 24 incense burners encompassing the five Classic ceramic phases of Palenque: Motiepa (A.D. 400-500), Cascadas (A.D. 500-600), Otulum (A.D. 600-700), Murcielagos (A.D. 700-770), and Balunté (A.D. 770-850). All the samples come from highly elaborate, flanged pedestal of incense burners that are undoubtedly assigned to a ceramic phase by means of their iconographic, morphological and stylistic analyses. Archeointensity measurements were performed with the Thellier-Thellier's method on pre-selected samples by means of their magnetic properties. We obtained archeointensities of very good technical quality from 19 of 24 pieces, allowing the determination of a precise mean value for each ceramic phase, between 29.1±0.9 μT and 32.5±1.2 μT. The firing temperatures of ceramics were estimated with Mössbauer spectroscopy between 700 °C and 1000 °C. These values ensure that a full thermo-remanent magnetization was acquired during the original heating. Our results suggest a relative stability of the field intensity during more than 400 years in this area. The abundance of archeological material in Mesoamerica contrasts with the small amount of archeomagnetic data available that are, in addition, of uneven quality. Thus, it is not possible to establish a trend of intensity variations in Mesoamerica, even using the global databases and secular variation predictions from global models. In this context, our high technical quality data represent a strong constraint for the Mesoamerican secular variation curve during the first millennium AD. The corresponding Virtual Axial Dipole Moments (VADM) are substantially smaller than the ones predicted by the last global geomagnetic models CALS3k.4, suggesting the need for additional data to develop a

  9. Remarques sur les stratifications sociales et les solidarités chez les Musulmans du Sindh colonial

    Directory of Open Access Journals (Sweden)

    Michel Boivin

    2012-01-01

    Full Text Available En 1843, les Britanniques conquéraient le Sindh pour consolider leur frontière occidentale face aux visées des Russes, mais aussi pour contrôler le commerce de la vallée de l’Indus qui débouchait sur la mer d’Oman et l’océan indien. Comme dans le reste de l’empire des Indes, les officiers eurent tôt fait de s’intéresser aux populations de cette province excentrée, qui constituait une frontière entre les territoires à majorité hindoue et le continuum musulman.Ils rédigèrent des rapports qui décrivaient les populations du Sindh et leurs activités, les comparant à l’organisation socio-économique des autres populations de l’empire, et essayant simultanément de les situer par rapport au schème idéologique de l’hindouisme. Ces rapports souvent minutieux, qui témoignaient d’une connaissance approfondie de ces populations, fournissent encore aujourd’hui la majeure partie de la documentation sur la question.Cette contribution étudie le lien entre la hiérarchisation des populations musulmanes et le renouvellement des solidarités dans la période coloniale, soit à peu près sur un siècle. Dans un premier temps, elle examine dans quelle mesure l’activité économique ou le métier déterminait le statut et le rang dans la société musulmane sindhîe. Puis elle aborde la question des solidarités du point de vue de la hiérarchisation des groupes. Elle tente alors de répondre à un double questionnement : quelle forme de solidarité correspondait à quel groupe, et au sein de quels groupes se produisit un renouvellement des solidarités.

  10. Research and application of hydrocarbon steam reformer ’s burners%烃类蒸汽转化炉燃烧器的研究与应用

    Institute of Scientific and Technical Information of China (English)

    徐凯

    2016-01-01

    针对KBR烃类蒸汽转化炉炉顶燃烧器工况恶化的现状,数值模拟计算了燃料组分、混合方式对燃烧特性的影响,对燃烧器形式及结构参数等关键因素进行了研究。在原有“燃料分段”加“烟气再循环”技术的基础上,提出了“空气分段”加“烟气再循环”的国产化改造方案。将原有“圆筒型燃料器”改造为新型超低NOx排放设计的“扁平式燃烧器”。通过改造,燃烧状况得到明显改善,达到了节能减排的目的。%According to the present situation of condition deterioration in the KBR hydrocarbon steam reformerˊs arch burners, the influences of fuel composition and mixed mode on the combustion characteristics were calculated by numerical simulation, and the key factors such as the form and structure parameters of the burner were studied. On the basis of the original "Staged-Fuel Burners" and "Flue Gas Recirculation" technology, a localized modification plan of "Staged-Air Burners” and "Flue Gas Recirculation" was proposed. The original "Cylinder Type Burner" was transformed into a new type of "Flat Flame Burner for the Design of Ultra Low NOx Emissions". By means of modification, the combustion state could be improved obviously, achieving the purpose of energy-saving and emission reduction.

  11. EXERGY ANALYSIS OF COMBUSTION PROCESS OF CERAMIC BURNER%陶瓷燃烧器燃烧过程的可用能分析

    Institute of Scientific and Technical Information of China (English)

    饶荣水

    2001-01-01

    Based on exergy analysis of combustion process,the exergy loss rate was presented to estimate the irreversible exergy loss.The paper computed exergy loss rate of combustion process of ceramic burner,and the results showed that compared with tube in tube type ceramic burner,the new type ceramic burner could preheat air and gas,raise theoretical combustion temperature of gas,reduce exergy loss rate during combustion process and raise utilization efficiency of energy.The essential differences between new type ceramic burner and tube in tube type ceramic burner were revealed from the point of view of exergy analysis.%在燃烧过程可用能分析的基础上,提出可用能损失率指标,它可用于衡量燃烧过程不可逆损失的程度。对陶瓷燃烧器燃烧过程的可用能损失率,计算结果表明:与套筒式陶瓷燃烧器相比,新型陶瓷燃烧器对空、煤气有预热作用,可提高煤气的理论燃烧温度,降低燃烧过程的可用能损失率,提高能量的有效利用率。从可用能的观点揭示了新型陶瓷燃烧器与套筒式陶瓷燃烧器的本质区别。

  12. Castelain Meunier Christine, Les métamorphoses du masculin

    Directory of Open Access Journals (Sweden)

    Alain Touraine

    2011-02-01

    Full Text Available Ce qui est le plus nouveau dans un livre sur les hommes est le simple fait de nommer les hommes comme une catégorie particulière, ce qu’on faisait et qu’on fait encore plus facilement pour les femmes. Et pour des raisons qui ne se réduisent pas à la tentation de considérer les femmes comme une “minorité”. Nommer les hommes peut avoir bien des sens différents et c’est pour lever nos incertitudes que nous lisons ce nouveau livre de Christine Castelain Meunier. Plusieurs livres et de nombreuses ...

  13. Le contentieux camerounais devant les instances sportives internationales

    Directory of Open Access Journals (Sweden)

    Dikoume François Claude

    2016-01-01

    Les acteurs du sport depuis lors, utilisent donc les voies de recours au niveau international soit vers les fédérations sportives internationales ou encore et surtout vers le TAS qui s'occupe des litiges de toutes les disciplines sportives. Il est question ici de faire un inventaire casuistique descriptif non exhaustif des requêtes contentieuses camerounaises portées devant les diverses instances sportives internationales ; ceci permettra de questionner l'esprit processuel et la qualité technique de leurs réclamations juridiques en matière sportive.

  14. Les écueils du double jeu

    Directory of Open Access Journals (Sweden)

    Séverin Muller

    2007-06-01

    Full Text Available À partir d’une expérience d’observation participante qui a consisté à travailler comme ouvrier puis à intégrer les bureaux de la direction dans un abattoir industriel, l’auteur étudie les effets cognitifs de la transgression d’un ordre établi dans l’entreprise : les ouvriers avec les ouvriers et les cadres avec les cadres. Les situations décrites de rupture avec les usages du milieu permettent de réfléchir aux façons d’être identifié selon les circonstances, aux formes d’instrumentalisation du chercheur sur son terrain, aux manières dont la confiance s’acquiert se maintient ou se perd dans un environnement conflictuel (selon quels critères propres à chaque groupe sommes nous acceptés, cooptés ou exclus ?. Finalement, la démarche transversale et le jeu transgressif qu’elle suggère participent à l’apprentissage des systèmes de référence non partagés au sein d’une même organisation.Starting from an experiment of participating observation which consisted in working as worker then to integrate the offices of the direction in an industrial slaughterhouse, the author studies the cognitive effects of the transgression of an order established in the company: workers with the workers and managers with the managers. The described situations of rupture with the uses of the social sphere make it possible to think of the ways of being identified according to circumstances, the shapes of « instrumentalisation » of the researcher on his field, with the ways in which confidence is acquired, is maintained or lost in a conflict environment (according to which specific criteria to each group are us accepted, co-opted or excluded?. Finally, the transverse way and the transgressive play that it suggests take part in the training of the systems of reference not shared in the same organization.A partir de un experimento de observación participante que consistió en trabajar como obrero antes de integrar las

  15. Oil burners: Crude oil, atomization, and combustion efficiency. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    The bibliography contains citations concerning fuel properties and boiler operations techniques to make maximum use of heavy crude oil, shale oil, and low grade fuels to reduce energy costs in boiler firing. Fuel properties pertain to chemical constituents, viscosity, desulfurization, and processing methods to upgrade the fuels. Operating techniques include atomization, dual-fuel burners, emission characteristics, and cost factors. Combustion efficiency is examined and some citations report on additives or processing techniques to improve the efficiency. The citations also report on studies of health effects in the use of synfuels, mostly as coal liquids to replace oil. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  16. Co-firing straw with coal in a swirl-stabilized dual-feed burner: modelling and experimental validation

    DEFF Research Database (Denmark)

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

    2010-01-01

    This paper presents a comprehensive computational fluid dynamics (CFD) modelling study of co-firing wheat straw with coal in a 150 kW swirl-stabilized dual-feed burner flow reactor, in which the pulverized straw particles (mean diameter of 451μm) and coal particles (mean diameter of 110.4μm......-lean core zone; whilst the coal particles are significantly affected by secondary air jet and swirled into the oxygen-rich outer radius with increased residence time (in average, 8.1s for coal particles vs. 5.2s for straw particles in the 3m high reactor). Therefore, a remarkable difference in the overall...

  17. Measurement of the flow field around flame stabilisers in an isothermal low NO{sub x} burner

    Energy Technology Data Exchange (ETDEWEB)

    Easson, W.J. [University of Edinburgh, Edinburgh (United Kingdom). Dept. of Mechanical Engineering

    1998-12-31

    A program of velocity measurements using Particle Image velocimetry was carried out on a 1/2 scale Low NO{sub x} Burner at International Combustion Ltd., Derby. Flow maps were recorded for a variety of coal particle sizes; and for smoke, in order to measure the air velocity. It was found that the smoke and 30 {mu} particles follow similar paths. However, the larger particles are not strongly affected by the air flow. Profiles of axial and radial velocities have been produced for direct comparison with Laser Anemometry measurements and the output from computer models. To obtain a high data return from closely spaced images in some of the tests it was necessary to find a technique of image enhancement. The final technique employed was image sharpening, and a number of tests were carried out to ensure that sharpening did not alter the velocity values. 6 refs., 17 figs.

  18. Les dimensions émotionnelles du terrorisme

    Directory of Open Access Journals (Sweden)

    Benjamin Ducol

    2013-10-01

    Full Text Available Par une volonté louable de rompre avec des approches psychologisantes du phénomène terroriste dominantes au cours des années 1960-70, les recherches contemporaines en matière de terrorisme(s et de violence(s politique(s ont très largement mis l’emphase sur la figure du « terroriste » comme acteur rationnel et stratégique. Face aux limites des approches rationalistes de l’engagement radical qui envisagent de manière réductionniste les individus au travers d’un calcul rationnel univoque en terme de coûts et d’incitatifs à l’action, il nous apparaît important de réintégrer dans les réflexions théoriques sur les phénomènes terroristes, les émotions afin d’en interroger le rôle dans la production d’une trajectoire violente. Le présent article entend proposer à cet égard un bilan critique des travaux universitaires actuels autour de l’engagement terroriste et une réflexion théorique mettant en lumière les contours d’un futur agenda de recherche accordant une place plus importante aux ressorts émotionnels de la violence politique clandestine. Contemporary research on terrorism(s and political violence(s have largely put the emphasis on the figure of the "terrorist" as rational and strategic player, in a break with psychoanalytical approaches to terrorism that were dominant from the 1960-1970’s. Given the limitations of rationalist approaches to radical commitment, and considering how reductionist is the understanding of individual participation to terrorism related activities through a rational calculation framework in terms of costs and incentives to action, it is important to reintegrate in the theoretical reflections on terrorist phenomena how emotions can play a role in leading potential terrorists down a violent path. This paper presents a critical assessment of current academic work surrounding the issue of violent radicalization and involvement in terrorism, and engages in a theoretical debate

  19. Les évolutions de la norme électrique

    CERN Document Server

    Gallauziaux, Thierry

    2014-01-01

    Découvrez pièce par pièce les évolutions de la norme électrique (NF C 15-100 applicable depuis le 1er juin 2003), et les équipements minimaux requis : nombre de socles de prises de courant, emplacement des points d'éclairages, prises de communication... Sachez choisir les nouveaux dispositifs de protection des circuits, désormais obligatoires : les interrupteurs différentiels de type A, les dispositifs de coupure du fil pilote des chauffages électriques, le parafoudre... Ce qu'il faut savoir sur les nouvelles prises téléphoniques et le réseau de communication domestique pour accueillir les nouveaux services multimédias et de communication (téléphonie, TV, Internet...).

  20. OGM Diffusion des OGM et impact pour les agriculteurs : quels sont les liens ?

    Directory of Open Access Journals (Sweden)

    Lemarie Stéphane

    2001-05-01

    Full Text Available Les OGM actuellement sur le marché présentent des innovations sur des fonctions de protection des plantes. Selon les problèmes de protection des plantes, les gains des agriculteurs liés à l’adoption des OGM sont très variables. Cette hétérogénéité pose d’importants problèmes méthodologiques pour pouvoir estimer correctement la distribution des gains pour l’ensemble des agriculteurs. Une synthèse de plusieurs études américaines est réalisée ici et met bien en évidence la diversité des méthodes utilisées, chacune d’elles présentant ses avantages et ses limites. Globalement, si la diffusion des OGM est un fait indéniable, les études ne permettent pas de tirer des conclusions aussi nettes quant à l’impact des OGM pour tous les agriculteurs qui adoptent ces produits, et cela en particulier pour le soja. Cette absence de conclusion s’explique en grande partie par la difficulté à mesurer certains facteurs qui influencent le comportement d’adoption, comme par exemple la simplification de la conduite des cultures. En contrepartie, il faut noter que les études présentées ici ne prennent pas en compte un certain nombre d’effets indirects qui peuvent faire diminuer les gains des agriculteurs.

  1. Photonic Metamaterials for Defence and Security Applications (Les meta-materiaux photoniques pour les applications de defense et de securite)

    Science.gov (United States)

    2008-04-01

    exceptionnelles qui ne sont pas facilement observables dans les matériaux naturels . La plupart des recherches sur les méta-matériaux ont été consacrées à...matériaux naturels ) est une des principales raisons qui a poussé les chercheurs à approfondir leurs études sur les méta-matériaux. Avec un index...rapports signal/bruit plus importants, une vitesse plus élevée, une taille réduite, et une gamme plus large pour les systèmes de capteurs optiques

  2. Marina Tsvetaeva, Les Carnets. 1913-1939

    Directory of Open Access Journals (Sweden)

    Katia Vandenborre

    2009-10-01

    Full Text Available Entrevoir le quotidien de Marina Cvetaeva avant son éternité, approcher sa personne avant sa personnalité, tout en remontant aux sources impossibles de sa création, tels sont les défis de la publication de ses Carnets.Ces quinze carnets réunissent en un volume vingt-six ans de notes, esquisses poétiques, extraits de lettres, chroniques du quotidien, listes de courses, réflexions. Ils commencent en 1913, Tsvetaeva étant alors une jeune mère de 21 ans, traversent les années de dénuement et d’ex...

  3. Les auteurs du numéro

    Directory of Open Access Journals (Sweden)

    2010-04-01

    Full Text Available Tatjana Barazon est docteur en philosophie et a soutenu sa thèse « Création et participation : le monde au seuil de l’être » en 2003 à Paris IV- Sorbonne. Elle a traduit La vie de Jésus de G.W.F. Hegel (Vrin, 2009 en collaboration avec Ari Simhon, avec qui elle travaille, ainsi qu’avec Jean-Marie Lardic, sur une autre traduction de Hegel « Les leçons de la Logique (1817 ». Elle s’intéresse à la question de la réception de la pensée de Bergson dans la phénoménologie et les neurosciences (htt...

  4. Santa Magdalena de les Tragines Altarpiece. Epilogue

    Directory of Open Access Journals (Sweden)

    Riu de Martín, M. Carme

    2007-06-01

    Full Text Available

    This is a work review of the article published in “Anuario de Estudios Medievales” 36/1 (2006, pp. 355-284. After the restoration of the pieces one has obtained new data about their iconography and their image’s symbolism.



    Revisió del treball que amb el mateix títol es va publicar a la revista “Anuario de Estudios Medievales”, 36/1 (2006, pp. 355-384. La restauració de les peces estudiades ha permès obtenir nous resultats sobre la iconografia i el sentit simbòlic de les imatges plasmades a l’esmentat retaule

  5. : (S') Investir dans les entreprises innovantes

    OpenAIRE

    2002-01-01

    International audience; L'avènement des nouvelles technologies de l'information a entraîné le développement d'une nouvelle économie et, en son sein, l'apparition d'entreprises d'avant-garde : les start-up. Celles-ci se définissent par leur mode de financement et par le pari qu'elles prennent sur une innovation. De ces deux aspects fondamentaux découle une série de conséquences. En amont, les entreprises voient leur logique de production perturbée par une logique du financement basée sur un « ...

  6. Les consequences de Tchernobyl et la sociopathologie

    OpenAIRE

    Laurent Bocéno

    2006-01-01

    Dans la situation de post-catastrophe aux alentours de Tchernobyl, la vie quotidienne est une correspondance constante entre l'institué et le vécu qui sont souvent analysés séparément. Avec l'approche par les sociopathologies, il est possible d'examiner le social entré dans le corps comme le résultat de l'intériorisation en nous, d'archétypes sociaux d'une part et d'autre part, de situations incorporées. Les sociopathologies sont liées aux formes d'institutionnalisation dont le sens est souve...

  7. Les industries agroalimentaires entre deux eaux.

    OpenAIRE

    2012-01-01

    un litre d’eau consommé par litre de lait transformé. Vingt litres par kilo de salade ensachée. L’eau, essentielle pour le nettoyage et la désinfection des produits alimentaires, doit être économisée. Parfois indésirable dans les aliments, elle doit aussi être contrôlée : 25% de l’énergie consommée par l’industrie laitière est utilisée pour concentrer le lait. a la croisée de la thermodynamique et de l’industrie, les chercheurs de l’unité sTLo, (science et technologie du lait et de l’œuf)...

  8. Les mammites : approche individuelle et de troupeau

    OpenAIRE

    Hanzen, Christian

    2015-01-01

    Objectif général : Ces chapitres présentent les notions de base relatives à l'anatomie et la physiologie de la glande mammaire au cours du cycle de lactation naturellement ou artificiellement induit. Il précise également les caractéristiques générales du lait. Il présente également le contexte de la production laitière mondiale. Il décrit enfin le système de contrôle qualitatif et quantitatif de la production laitière en Wallonie. Ces notions constituent autant de prerequis indispensables à u...

  9. Les microémulsions Microemulsions

    Directory of Open Access Journals (Sweden)

    Bavière M.

    2006-11-01

    Full Text Available Depuis une quinzaine d'années, les microémulsions intéressent l'industrie pétrolière, en effet, leur miscibilité apparente avec l'eau et les hydrocarbures, jointe à des propriétés originales de stabilité et de viscosité, en fait des fluides de drainage de l'huile, même résiduelle, extrêmement efficaces, leur emploi est également recommandé pour la stimulation des puits d'injection ou de production. La présente étude bibliographique s'applique à situer d'abord les microémulsions dans le contexte des solutions micellaires, puis à présenter les théories qui expliquent leur formation, leur structure et leurs propriétés, et enfin à décrire le procédé de récupération du pétrole tel qu'il a été étudié au laboratoire, et mis en oeuvre sur champ pendant la dernière décennie. In the last fifteen years, the petroleum industry has become interested in microemulsions. Their apparent miscibility with water and hydrocarbons as well as their original properties of stability and viscosity make them extremely effective oil drainage fluids, even for residual oil. They are also recommended for stimulating injection or production wells. This bibliographic survey attempts first to situate microemulsions with in the context of micellar solutions and then to review theories explaining their formation, structure and properties. lastly, a description is given of an oil recovery process that has been laboratory researched and applied in the field during the last decade.

  10. Vaccin antipneumococcique dans les maisons de repos

    OpenAIRE

    Michiels, B.

    2010-01-01

    Abstract: Cette RCT montre quune vaccination antipneumococcique de personnes fort âgées (moyenne de 85 ans) résidant en maison de repos au Japon, en complément dune vaccination anti-influenza, diminue les cas de pneumonie et de décès lié à une pneumonie à pneumocoques. Aucune conclusion nest possible pour des personnes moins âgées ni pour des personnes vivant au domicile.

  11. Qui gouverne les industries ?

    Directory of Open Access Journals (Sweden)

    William Genieys

    2010-07-01

    Full Text Available La question de savoir qui gouverne l’économie a longtemps fasciné les sciences sociales sans pour autant souvent générer de résultats probants et rigoureux. Bernard Jouve a tenté d’y répondre en se focalisant sur l’élite de chacune des métropoles qu’il a étudiée. Ce texte prolonge son travail en changeant de focale pour aborder plutôt les élites qui régulent chaque industrie en présentant leur «  programme » respectif. Après avoir exposé les développements théoriques menant à ce concept « d’élite programmatique », l’article les croise avec une approche du gouvernement des industries afin de tracer une nouvelle voie vers une meilleure compréhension du rôle du politique dans l’économie.The question «who governs the economy ?» has fascinated social science for years without often generating stimulating and rigorous results. Bernard Jouve attempted to reply to it by focusing on the elite of each metropole he studied. This text extends his work by changing the focus in order to study the elites who regulate each industry through promoting their respective «programme». Having first presented the theoretical developments that produced the concept of «programmatic elite», the article combines it with an approach to the government of industries in order to set out a new route map towards better understanding of the role of politics in the economy.

  12. Les noms en -ance : un panorama

    Directory of Open Access Journals (Sweden)

    Knittel Marie Laurence

    2016-01-01

    Full Text Available Ce travail examine les noms terminés par la forme ance (dorénavant Nance construits sur des bases verbales (appartenance, adjectivales (élégance, ou relevant potentiellement de ces deux catégories (méfiance. Nous nous intéressons aux propriétés des Nance eux-mêmes, en particulier leurs spécificités syntaxiques et sémantiques. En tant que noms déverbaux, ils sont susceptibles de décrire des évenances et de posséder une structure argumentale similaire à celle du verbe de base ; en tant que noms désadjectivaux, la dénotation prioritairement attendue est celle de propriété. Nous soulevons la question de l’analyse des formes apparentées à la fois à un verbe et à un adjectif, afin de déterminer quelle est la base effective de la forme nominale, ou bien s’il existe deux Nance formellement identiques, l’un déverbal, l’autre désadjectival. Enfin, nous examinons la relation entre les Nance déverbaux et les participes présents, formellement proches.

  13. Les Chaines entrelacées Dans Les Bienveillantes De Jonathan Litte

    Directory of Open Access Journals (Sweden)

    Amany Mohamed Raghen

    2012-07-01

    Full Text Available Né en 1967 à  New-York, Jonathan Littell a publié à l’âge de 22 ans un premier récit de science-fiction en anglais Bad Voltage qui fut suivi d’une vaste production romanesque1. Dans les années 90, il était volontaire pour Action contre la Faim2 et fut témoin oculaire des génocides humains. Culture bilingue, goût pour la Science-fiction, idéologie humanitariste: tels sont en bref les substrats sur lesquels se centre le cheminement littéraire de Littell.Les Bienveillantes(2006, best-seller traduit dans le monde entier est une œuvre de fiction sur les camps de la mort: un personnage central, Maximilian  Aue, déambulant parmi les groupes mouvants de tuerie (Enzatgruppen ou "Endlösung"3, torture à ciel ouvert (la Shoah par balles4, camps d’extermination et  chambres à gaz.

  14. Quines empreses han aguantat millor la crisi, les empreses familiars o les no familiars?

    Directory of Open Access Journals (Sweden)

    Jose Luis Gallizo

    2014-12-01

    Full Text Available Objecte: En aquest estudi és porta a terme un anàlisi comparatiu sobre l’evolució de l’estructura econòmica i financera que presenten les empreses familiars i no familiars de Catalunya en un context d’intensa crisi econòmica. La seva finalitat és poder donar resposta a dos qüestions principals: identificar les característiques diferencials de l’EF respecte a l’EnF i comprovar si aquestes característiques diferencials han permès a les EF aguantar millor la crisi econòmica. Disseny/metodologia: S’ha analitzat una mostra de 750 grans i mitjanes empreses de Catalunya (550 familiars i 200 no familiars durant el període 2008-2012. Les dades s’han obtingut a través de la base de dades SABI, i per a la classificació de les empreses en familiars i no familiars s’ha dut a terme una comprovació individual de cadascuna d’elles per evitar habituals errors de classificació. Posteriorment les empreses s’han classificat en funció de la seva dimensió per dotar d’una major robustes els resultats. També s’ha procurat que la distribució d’empreses per sectors fos similar en les diferents categories per evitar que un efecte sectorial pogués tergiversar els resultats de l’estudi. Aportacions i resultats: L’estudi ha permès constatar les hipòtesis establertes sobre el finançament de les empreses familiars i concloure que aquestes presenten una estructura financera diferent a les Empreses no familiars. Les empreses familiars als seus balanços, presenten un major nivell d’autofinançament gràcies a la seva menor distribució de dividends. A més a més, les EF presenten millors resultats en quant a nivells de cobertura i liquiditat, ja que es troben més capitalitzades i presenten uns nivells d’endeutament inferior que les Empreses no familiars. Aquestes característiques patrimonials i financeres han contribuït a que les empreses familiars aguantin millor els anys de crisi, produint-se durant aquests anys

  15. Modèles types de lettres et courriers électroniques

    CERN Document Server

    Fayet, Michelle

    2008-01-01

    Bien rédiger les lettres et mails professionnels renforce l'image de qualité de votre entreprise. La 2e édition de ce livre vous offre les clés essentielles pour améliorer la rédaction de votre courrier professionnel et vous propose, par le CD-Rom joint, des modèles de lettres et e-mails directement utilisables. Ils couvrent les situations les plus courantes rencontrées quotidiennement dans une entreprise : les demandes de renseignements, les commandes, les livraisons, les facturations, le recrutement, la gestion du personnel, les échanges avec les partenaires, les banques, les administrations. Indispensable pour rédiger des courriers efficaces, ce guide est un outil de travail incontournable pour tous salariés en charge de la rédaction du courrier, et particulièrement pour les secrétaires et assistantes.

  16. Advanced Burner Reactor with Breed-and-Burn Thorium Blankets for Improved Economics and Resource Utilization

    Energy Technology Data Exchange (ETDEWEB)

    Greenspan, Ehud [Univ. of California, Berkeley, CA (United States)

    2015-11-04

    This study assesses the feasibility of designing Seed and Blanket (S&B) Sodium-cooled Fast Reactor (SFR) to generate a significant fraction of the core power from radial thorium fueled blankets that operate on the Breed-and-Burn (B&B) mode without exceeding the radiation damage constraint of presently verified cladding materials. The S&B core is designed to maximize the fraction of neutrons that radially leak from the seed (or “driver”) into the subcritical blanket and reduce neutron loss via axial leakage. The blanket in the S&B core makes beneficial use of the leaking neutrons for improved economics and resource utilization. A specific objective of this study is to maximize the fraction of core power that can be generated by the blanket without violating the thermal hydraulic and material constraints. Since the blanket fuel requires no reprocessing along with remote fuel fabrication, a larger fraction of power from the blanket will result in a smaller fuel recycling capacity and lower fuel cycle cost per unit of electricity generated. A unique synergism is found between a low conversion ratio (CR) seed and a B&B blanket fueled by thorium. Among several benefits, this synergism enables the very low leakage S&B cores to have small positive coolant voiding reactivity coefficient and large enough negative Doppler coefficient even when using inert matrix fuel for the seed. The benefits of this synergism are maximized when using an annular seed surrounded by an inner and outer thorium blankets. Among the high-performance S&B cores designed to benefit from this unique synergism are: (1) the ultra-long cycle core that features a cycle length of ~7 years; (2) the high-transmutation rate core where the seed fuel features a TRU CR of 0.0. Its TRU transmutation rate is comparable to that of the reference Advanced Burner Reactor (ABR) with CR of 0.5 and the thorium blanket can generate close to 60% of the core power; but requires only one sixth of the reprocessing and

  17. Research and Development of Ethylene Cracking Furnace Hearth Burner%大型裂解炉用底部燃烧器的国产化研发

    Institute of Scientific and Technical Information of China (English)

    李金科; 徐红兵; 刘韫砚; 张建

    2012-01-01

    Aiming at the request of ethylene cracking furnace hearth burner for the flame shape, the flame stability, the heat flux distribution and the NO, emission, by fuel classification method combined with research of the burner tips and the wind channel, the original structure of the hearth burner was determined. The burner structure was improved by computational fluid dynamics simulation, and the pollution emission and the heat flux distribution were validated through thermal state test. Then, the hearth burner of large-scale ethylene cracking furnace was developed successfully. Industrial application of the hearth burner indicated that the combustion was complete and the flame was flat and steady. The max wall temperature of the furnace tube was 1 044 ℃ after the furnace running 55 d and NOx emission was 127 mg/m3(standard state).%针对大型裂解炉用底部燃烧器对火焰形状、火焰刚性、热通量分布和NOx排放的要求,利用燃料分级原理,结合喷嘴和配风方面的研究确定了燃烧器的结构型式;通过多方案流体动力学模拟计算对燃烧器的结构进行改进,同时通过热态试验验证了燃烧器的污染物排放、热通量分布等性能,最终开发出具有自主知识产权的大型裂解炉用底部燃烧器.在1Mt/a乙烯装置裂解炉的工业应用结果表明,裂解炉内燃烧完全,火焰扁平刚直,运行55d时管壁最高温度为1044℃,NOx放量为127mg/m3(标准状态),燃烧器的性能完全满足裂解炉的工艺要求及环保要求.

  18. Powder Leakage Cause Analysis and Control Measures of Double Cyclone Pulverized Coal Burner%双旋风煤粉燃烧器漏粉原因分析和控制措施

    Institute of Scientific and Technical Information of China (English)

    王勇; 蒋治其

    2015-01-01

    "W"type flame boiler burner is pulverized coal burner. Because of the large number and big size of the devices, the design layout is compact and there are many flange connections between devices. In order to ensure installation quality and operation safety of the burner, this article analyzes the causes and introduces the control measures of burner powder leakage from the aspect of installation.%“W”型火焰锅炉燃烧器为旋风煤粉燃烧器,因其设备多、设备尺寸较大,因而设计布置紧凑、设备间法兰连接较多。为保证燃烧器安装质量以及运行安全,本文从安装角度出发对燃烧器漏粉进行了原因分析和控制措施。

  19. Cultures et politiques dans les Alpes contemporaines

    Directory of Open Access Journals (Sweden)

    Bernard Debarbieux

    2009-03-01

    Full Text Available Plus que jamais, l’espace alpin est marqué par le déploiement de flux toujours plus variés, toujours plus puissants, et symétriquement par la multiplication d’initiatives destinées à conforter ou à régénérer l’idée de localité. Quelles spatialités et quelles territorialités travaillent les populations alpines aujourd’hui ? Quelles sont les figures contemporaines de la circulation et des flux, et les figures complémentaires de l’ancrage et de la refondation territoriale ? Voici les questions que cet essai se propose de développer. Ce texte reprend le contenu d’une conférence donnée dans le cadre de la célébration du centenaire de l’Institut de Géographie Alpine. Cette conférence, comme les autres données à cette occasion, avait adopté une forme libre dressant un bilan et des perspectives de la situation alpine. La trace écrite adoptée ici prend alors logiquement la forme d’un essai.More than ever before, the Alps are affected by increasingly varied and powerful flows and equally by the multiplication of initiatives designed to strengthen or regenerate the idea of “locality” (place. What spatialities and what territorialities activate the populations of the Alps today? What are the contemporary figures relating to circulation and flows and the complementary figures concerning spatial “anchoring” or fixity and new territorial foundations? These are the questions that this essay, proposes to develop. This text takes another look at the subject of a lecture given as part of celebrations to mark the centenary of the Institut de Géographie Alpine. This lecture, like the others given on this occasion, adopted a free format, presenting a report on the current situation in the Alps and prospects for the future. The written format adopted here logically takes the form of an essay. Readers looking for detailed illustrations and references are referred to three scientific articles published by the same

  20. Les kystes hydatiques du foie rompus dans les voies biliaires: a propos de 120 cas

    Directory of Open Access Journals (Sweden)

    Mountassir Moujahid

    2011-11-01

    Full Text Available s et une anastomose bilio digestive choledoco duodenale dans 10 cas. La duree moyenne d�hospitalisation etait de 20jours. Nous deplorons deux deces par choc septique et un troisieme par encephalopathie secondaire a une cirrhose biliaire. La morbidite etait representee par huit abces sous phrenique, douze fistules biliaires prolongees et deux occlusions intestinales. Les kystes hydatiques rompus dans les voies biliaires representent la complication la plus grave de cette pathologie benigne. Le traitement repose sur des methodes radicales qui sont d�une efficacite reconnue, mais de realisation dangereuse et les methodes conservatrices, en particulier la deconnexion kysto biliaire qui est une methode simple et qui donne de bons resultas a court et a long terme.

  1. Les recherches des hispanistes sur les médias (1985-1996

    Directory of Open Access Journals (Sweden)

    Jean-Michel Desvois

    2007-05-01

    Full Text Available De 1986 à 1996, période pour laquelle nous avons effectué ce bilan, un intérêt croissant s'est manifesté pour la recherche sur les médias et notamment sur la presse. Un noyau dur d'une vingtaine de chercheurs a produit avec régularité ouvrages et articles sur ces domaines en les considérant à part entière, mais bien d'autres les ont abordés de façon oblique et ont ainsi contribué à une production scientifique qui représente près de trois cents références, dont plus de vingt thèses.Malgré l'ab...

  2. Les erreurs des étudiants slovènes dans les productions écrites

    Directory of Open Access Journals (Sweden)

    Nataša Žugelj

    2007-12-01

    Full Text Available Jusqu'aux anneés 70 du X.Xe siècle, les enseignants avaient tendance à évacuer au maximum l'erreur et àne pas mettre l'élève en situation d'échec. Ainsi, le linguiste Corder (1976 et les béhavioristes défendaient l'idée qu'une bonne méthode doit conduire à un apprentissage sans erreur. Si les erreurs se produisent, c'est que la méthode n'est pas correctement conçue, OU bien que des circonstances particulières liées àl'élève (inattention,  fatigue,  stress... conduisent à une  performance imparfaite.

  3. Quelques commentaires sur les personnages de fiction

    Directory of Open Access Journals (Sweden)

    Umberto Eco

    2010-06-01

    Full Text Available L’auteur met en place des observations et développe des analyses sur le statut des personnages de fiction, mettant à contribution les ressources de l’histoire, de la littérature, de la sémiotique, de la logique et de la narratologie. De quelle vie particulière vivent les personnages de roman, qui fait que nous sommes capables de les tenir pour plus réels que des personnages réels, et que nous sommes enclins à éprouver les sentiments qu’ils éprouvent, même si nous savons qu’ils n’existent pas ? Comment ces personnages de fiction existent-ils, selon quelle « partition » leur existence se développe-t-elle au point d’interférer avec la nôtre ? L’interrogation porte sur la nature de ce flux émotionnel qui s’écoule du lecteur vers les personnages de fiction et les investit de valeur, sur ce qui se projette de la vie vers le roman, entraînant avec lui le lecteur qui se trouve de la sorte impliqué malgré lui dans l’histoire, et se trouve pris dans le mécanisme de l’identification et de la vie fictive.Some commentaries about fiction charactersPutting into form a number of observations and developing an analysis on the status of fiction characters, the author draws on resources coming from history, literature, semiotic, logic et narration. What is that particular life lived by fiction characters that enable us to consider them as being more real than real characters, and to experience the feelings that they experience, even though we know that they do not exist? How do these characters exist? In other words, according to what “script” does their existence develop to the point of interfering with ours? The questioning centres on the nature of the emotional flux which flows from the reader towards the fictional characters thus giving them value, and on what it is which is projected from real life towards the novel and which is capable of sweeping up the reader who, without having particularly intended to do

  4. El treball amb alumnat TDAH : El treball de les habilitats socials i les emocions

    OpenAIRE

    Cañadas Rodríguez, Antònia

    2012-01-01

    El treball presenta una intervenció que busca afavorir el desenvolupament de les capacitats relacionals de l'alumnat amb Trastorn per Dèficit d'Atenció amb Hiperactivitat (TDAH). La intervenció té en compte l'enfocament cognitiu-conductual, a més del model constructivista de l'ensenyament i el model d'assessorament col·laboratiu. A més, s'ha elaborat un programa d'activitats per a l'ensenyament de les habilitats socials i emocions basat en els programes desenvolupats per Monjas (1993) i Orjal...

  5. Les transformations de l'image de Saladin dans les sources occidentales

    Directory of Open Access Journals (Sweden)

    Jean Richard

    2009-05-01

    Full Text Available Le personnage de Salāh al-din Yūsuf, officier kurde au service de Nūr al-dïn devenu maître de l'Égypte puis de Damas et enfin d'Alep, et fondateur de l'empire ayyoubide, a été fort controversé de son vivant avant de devenir pour la postérité « le plus pur des héros de l'Islam ». Pour ses adversaires, les Francs d'Orient, il a de bonne heure suscité leur curiosité, et ceux-ci ont recueilli des informations qu'ils ont utilisées, dès avant 1187, dans un Carmen de Saladino où l'aventurier qu'il était à leurs yeux est présenté sous des traits peu recommandables. Son manque de fidélité envers ses maîtres est particulièrement souligné. Les coups très durs qu'il a portés aux Francs ont été assortis de traits de cruauté ; mais ce sont les manifestations d'un esprit chevaleresque, dont les valeurs étaient communes aux deux camps, qui ont vite retenu l'attention. Le trouvère Ambroise le regarde encore comme un ennemi fort capable de perfidie ; mais le traducteur de Guillaume de Tyr adoucit les remarques du livre qu'il mettait en français pour le rendre plus sympathique. Les textes de caractère épique où il apparaît dans la première moitié du XIIIe siècle (Estoires d'Outremer, Ordene de Chevalerie accentuent ce caractère. Mais c'est dans le second cycle de la croisade qu'on le pare des qualités les plus éminentes qu'on attend d'un chevalier. On lui prête des origines chrétiennes (La fille du comte de Ponthieu et on lui attribue le beau rôle, en insistant sur sa générosité et sur sa bravoure, en lui faisant arbitrer des controverses religieuses, en lui prêtant enfin une aspiration à une mort chrétienne, qui sont bien loin du portrait que faisaient de lui les Francs de la fin du XIIe siècle.

  6. Les lexiques des jeunes dans les discours écrits des blogs : pour une approche descriptive

    Directory of Open Access Journals (Sweden)

    Lorenz Paulina

    2014-07-01

    Full Text Available S’il ne faut pas confondre ce qui est appelé communément « langage SMS » et « langage des jeunes », nous avancerons toutefois que les pratiques langagières écrites des jeunes sur les supports modernes de communication, et notamment dans les blogs, présentent des particularités encore peu étudiées. Les traits observables les plus saillants sont ceux de la morphologie graphique, mais il n’en reste pas moins que certains jeunes utilisent des lexiques particuliers dans les blogs qui méritent une attention particulière. Nous nous proposons donc d’étudier les différents lexiques utilisés par des jeunes de 12 à 22 ans dans les blogs de la plateforme skyrock.com aux niveaux de sa diversité, de ses usages sémantiques variable d’un scripteur à l’autre pour un même mot, et de ses particularités morphosyntaxiques. En effet, nous observerons des lexiques divers allant des lexiques perçus comme relevant des cités à des lexiques perçus comme étant « branchés-jeunes », ou encore à des lexiques propres aux supports modernes de communication. Ainsi, nous analyserons des lexiques variés dans leurs usages écrits tels que bolos, bédave, gérer, ouf, tigen, ou encore des lexiques empruntés tels que mouv, full, etc., ainsi que des emplois particuliers de séquences autonomes comme lol. Quelques questions périphériques complèteront notre analyse telle que celles qui concerne l’influence des usages lexicaux entre pairs et le savoir partagé, la distinction de différentes communautés en fonction des lexiques utilisés, ou encore la variabilité des représentations graphiques d’un même mot.

  7. Les lieux du sacré dans les Miracula sancti Germani d’Heiric d’Auxerre et les Gesta pontificum Autissiodorensium

    Directory of Open Access Journals (Sweden)

    Dominique Iogna-Prat

    2004-09-01

    Full Text Available Comment cerner la notion de sacré dans les textes carolingiens que sont les Gestes des évêques d’Auxerre et les Miracles de saint Germain écrits par l’un des maîtres de l’école carolingienne d’Auxerre, Heiric ? Une étude lexicale précise des mots latins employés par les auteurs permet d’approcher au plus près les concepts renvoyant aux lieux du sacré. Ce sujet de maîtrise. suggéré par D. Iogna-Prat et réalisé sous la direction de M. Bourin (université de Paris I-Panthéon Sorbonne, avec l’aid...

  8. 5th Symposium on Hybrid RANS-LES Methods

    CERN Document Server

    Haase, Werner; Peng, Shia-Hui; Schwamborn, Dieter

    2015-01-01

    This book gathers the proceedings of the Fifth Symposium on Hybrid RANS-LES Methods, which was held on March 19-21 in College Station, Texas, USA. The different chapters, written by leading experts, reports on the most recent developments in flow physics modelling, and gives a special emphasis to industrially relevant applications of hybrid RANS-LES methods and other turbulence-resolving modelling approaches. The book addresses academic researchers, graduate students, industrial engineers, as well as industrial R&D managers and consultants dealing with turbulence modelling, simulation and measurement, and with multidisciplinary applications of computational fluid dynamics (CFD), such as flow control, aero-acoustics, aero-elasticity and CFD-based multidisciplinary optimization. It discusses in particular advanced hybrid RANS-LES methods. Further topics include wall-modelled Large Eddy Simulation (WMLES) methods, embedded LES, and a comparison of the LES methods with both hybrid RANS-LES and URANS methods. ...

  9. Les relations Sud-Sud : culture et diplomatie

    OpenAIRE

    Abdenur, Adriana Erthal; Boisard, Stéphane; Boito, Armando; Brochier, Christophe; Brun, Élodie; Droulers, Martine; Dumont, Juliette; Forite, Camille; Galvão, Andréia; Lockhart, Nicolás Falomir; Marcelino,Paula; Marques-Pereira, Bérengère; Ramírez Barajas, Arlen Eugenia; Rodríguez Echeverría, María del Rocío; Sarr, Mamadou Lamine

    2016-01-01

    Le dossier central n° 80 des CAL s'intéresse aux relations entre l’Amérique latine et les pays du Sud, à travers le prisme de la culture, jusqu’à présent peu étudié, et pourtant fondamental dans le jeu des influences intergouvernementales. Quels sont les instruments de ce soft power? Quels sont les acteurs et les publics visés? Quelle image les différents pays cherchent-ils à projeter? Révélateurs de l’importance de la culture en politique étrangère, les articles rassemblés ici traitent de la...

  10. Principles of Selecting Type of Direct Flow Pulverized Coal Burner before Retrofit%直流煤粉燃烧器改造前的选型原则

    Institute of Scientific and Technical Information of China (English)

    李凤瑞

    2001-01-01

    针对锅炉燃烧器改造问题,提出在燃烧器改造前如何根据锅炉实际情况选择合适燃烧器类型的5项选型原则,包括煤种匹配原则、炉型匹配原则、工作业绩及创新性原则、经济性及安装检修方便性原则、运行自适应原则。对电厂煤粉燃烧器的改造有一定参考作用。%Which structure type of burner should be adopted for various utilities pulverized coal-fired boilers﹖ This paper puts forward five principles of selecting burner's type being of directive significance for the power plant that is going to retrofit burners.

  11. Différences dans les expressions faciales selon l'âge et le sexe

    OpenAIRE

    Houstis, Odyssia

    2010-01-01

    Notre but était de valider une méthode qui nous permet de mesurer les expressions faciales, d'appliquer cette méthode pour évaluer quantitativement les expressions faciales chez les adultes et chez les enfants, et de comparer les résultats obtenues pour les enfants en croissance et les adultes afin de pouvoir estimer les effets de l'âge et du sexe. Notre méthode 2-dimensionnelle est fiable et utile pour mesurer quantitativement les expressions faciales d'une façon simple, efficace, et peu coû...

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

    Science.gov (United States)

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

    2017-02-01

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

  13. (francuski Les temples payens de Sirmium

    Directory of Open Access Journals (Sweden)

    Jeremić Miroslav

    2006-01-01

    Full Text Available (farncuski Les édifices de culte païens ont été ici considérés en distinguant deux groupes selon leur position par rapport aux remparts. Le premier de ces groupes incluant les ouvrages situés en dehors de l'enceinte a déjà fait l'objet de plusieurs publications de sorte que ce travail se contente de rappeler brièvement leurs principales caractéristiques au début du texte. Lorsqu'il s'agit du Sirmium intra muros, nonobstant la présence de vestiges de murs massifs et de plastique architecturale décorative dans la partie centrale de la ville antique autorisant d'envisager la présence de temples païens, l'ensemble de la littérature publiée ne fait aucune mention de tels édifices. Les résultats d'une analyse a posteriori du matériel archéologique enregistré dans la documentation conservée à l'Institut archéologique de Belgrade, ainsi que l'observation du matériel lapidaire et décoratif des dépôts du Musée du Srem à Sremska Mitrovica ont permis à l'auteur de ce travail de constater (avec toute la réserve voulue dans ses conclusions que l'espace situé à l'est du forum accueillait, pour le moins quatre temples païens. L'existence de ces édifices de culte a été située au sein de divers intervalles compris entre le IIe et le IVe siècle. Il est intéressant de noter que le plus ancien d'entre eux (IIe siècle, dégagé sur le site 42, était doté d'une construction portante en bois. Un peu plus au nord ont été exhumés les vestiges d'un édifice de culte (59 datant du IIIe-IVe siècle qui pourrait être identifié avec un fanum gallo-romain, mais cela restera pour l'instant de l'ordre de l'hypothèse. Plus à l'est, sur une vaste plate-forme en dalles de marbre ont été érigés vers la fin du IIIe ou au début du IVe siècle deux autres temples (sites 43 et 47. Malheureusement un certain nombre de questions, entre autres relatives à leur structure et leur dédicace, ne pourrons ici trouver une réponse d

  14. Contrats d'éleveurs dans les Pennines

    OpenAIRE

    Whitby, Martin; Walsh, Mary

    2004-01-01

    Les exploitants anglais ont été les premiers européens à faire l'expérience de l'article 19. Les deux auteurs tentent de cerner le profil social de ces agriculteurs. Une analyse typologique de la population participante indique que, au-delà de la recherche d'un revenu additionnel, peut s'exprimer dans l'adhésion contractuelle un certain souci de protection de la nature. Si globalement les changements de pratiques agricoles restent limités, on observe néanmoins certains infléchissements...

  15. Ecotoxicité du nickel pour les organismes marins

    OpenAIRE

    Andral, Bruno

    1994-01-01

    Selon les différentes données receuillies, le nickel parait beaucoup moins toxique que certains autres métaux lourds comme le mercure, le cadmium, le chrome... Des essais de toxicité aigue font toutefois apparaître des seuils de toxicité inférieurs au mg/l notamment chez les crustacés qui semblent les organismes les plus sensibles à ce métal. A des concentrations de l'ordre de 30 à 100µg/l, le nickel exerce des effets inhibiteurs sur la reproduction et le développement embryonnaire de plusieu...

  16. les associations à la marque et le capital marque

    OpenAIRE

    MERABET, AMINA

    2014-01-01

    L'objet du premier chapitre est une revue de la littérature sur les notions du consommateur, notamment la marque.La deuxiéme partie aborde question de l'image de la marque et les associations .le troisiéme aborde les différentes approches du capital marque.le chapitre quatre développe la méthodologie relatives aux hypothéses issue de littérature, les résultats empiriques ainsi que la discussion des résultats.

  17. Guide Suva de l'assurance contre les accidents

    CERN Document Server

    2004-01-01

    Le présent Guide de la Suva permet au lecteur de se retrouver dans les dispositions légales sur l’assurance-accidents. Il est divisé en trois parties: La première partie commente en neuf chapitres la loi sur l’assurance-accidents et la loi fédérale sur la partie générale du droit des assurances sociales, ainsi que leurs ordonnances. Chaque chapitre est précédé des questions les plus fréquemment posées à propos des sujets qui y sont traités. Les réponses succinctes à ces questions facilitent l’approche des différents sujets et donnent un aperçu du contenu du chapitre. Dans la partie explicative, les dispositions concernées font l’objet d’une référence dans la marge. La deuxième partie contient toutes les lois et ordonnances importantes pour l’acti vité quotidienne de la Suva (parfois seulement sous forme d’extraits). Des couleurs différentes permettent de mieux les distinguer. La troisième partie regroupe les moyens d’information et les adresses de la Suva les plus imp...

  18. Comparative study of the combustion characteristics of slot burner%缝隙式燃烧器燃烧特性对比研究分析

    Institute of Scientific and Technical Information of China (English)

    刘艳领; 陈玉忠

    2012-01-01

    The paper introduced varies of typical construction characteristics of the slot burner. Through comparative analysis of the stability, combustion economy, slagging property of the W - type flame boiler in different slot burner, the paper presented the improving direction of the slot burner, which layout the exhaust steam in the second tuyere near the center of the furnace health and layout the anti - slagging second wind in the primary wind front and rear wall side.%介绍了几种典型的缝隙式燃烧器的结构特点,通过对不同缝隙式燃烧器“W”火焰锅炉的燃烧稳定性、燃烧经济性、结渣特性的对比分析,指出了缝隙式燃烧器的改进方向,即乏汽应布置于靠炉膛中心侧的二次风喷口处,在一次风靠前后墙侧布置防结渣的二次风。

  19. Studies on Low Calorific Value Coal Bed Methane Burner and Optimal Analysis%低热值煤层气燃烧器的研究

    Institute of Scientific and Technical Information of China (English)

    杨盼盼; 施永红

    2015-01-01

    低热值煤层气一般与固体燃料混烧,被广泛应用于发电、化工等工业领域。因此,研究和开发适合低热值煤层气的燃烧器具有重要的工业应用价值和学术意义。介绍了三种燃气燃烧器的结构、工作原理及其特点,对其燃烧效率等进行分析对比。并介绍了低热值煤层气燃烧器的研究进展、存在问题和未来的发展趋势。%Low calorific value CBM generally burn with solid fuel.It is widely used in industrial fields for power generation, chemical industry and so on.Therefore, researching and development suited to low calorific value coal bed methane burner has important industrial application value and academic significance. This paper introduces three gas burner structure, working principle and characteristics, comparatively analyzed to combustion efficiency,etc. And describes the research progress,the existing problems and future trends in low calorific value coal bed methane burner.

  20. Real-Time Thermographic-Phosphor-Based Temperature Measurements of Thermal Barrier Coating Surfaces Subjected to a High-Velocity Combustor Burner Environment

    Science.gov (United States)

    Eldridge, Jeffrey I.; Jenkins, Thomas P.; Allison, Stephen W.; Cruzen, Scott; Condevaux, J. J.; Senk, J. R.; Paul, A. D.

    2011-01-01

    Surface temperature measurements were conducted on metallic specimens coated with an yttria-stabilized zirconia (YSZ) thermal barrier coating (TBC) with a YAG:Dy phosphor layer that were subjected to an aggressive high-velocity combustor burner environment. Luminescence-based surface temperature measurements of the same TBC system have previously been demonstrated for specimens subjected to static furnace or laser heating. Surface temperatures were determined from the decay time of the luminescence signal of the YAG:Dy phosphor layer that was excited by a pulsed laser source. However, the furnace and laser heating provides a much more benign environment than that which exists in a turbine engine, where there are additional challenges of a highly radiant background and high velocity gases. As the next step in validating the suitability of luminescence-based temperature measurements for turbine engine environments, new testing was performed where heating was provided by a high-velocity combustor burner rig at Williams International. Real-time surface temperature measurements during burner rig heating were obtained from the decay of the luminescence from the YAG:Dy surface layer. The robustness of several temperature probe designs in the sonic velocity, high radiance flame environment was evaluated. In addition, analysis was performed to show whether the luminescence decay could be satisfactorily extracted from the high radiance background.