Burning Pulverized Fuel Patents (Class 110/347)
  • Patent number: 6237513
    Abstract: A method of operating a solid fuel-fired furnace having a plurality of windboxes each having a plurality of compartments through which fuel and air are introduced into the furnace and a fuel and air arrangement operated in accordance with the method are provided. Solid fuel is fed into the furnace and primary air and fuel are fed through the same compartments into the furnace in a direction tangential to a first imaginary circle generally located in the center of the furnace so as to interact with the fuel fed into the furnace so as to create a rotating fireball. Overfire air and offset air are also supplied into the furnace, the offset air being that portion of the air supplied to the furnace so as to support a second imaginary circle concentric to, and having a larger diameter than, the first imaginary circle.
    Type: Grant
    Filed: December 21, 1998
    Date of Patent: May 29, 2001
    Assignee: ABB Alstrom Power Inc.
    Inventors: Rebecca L. Tobiasz, Douglas J. Hart, Robert D. Lewis, James P. Sutton, Bruce F. Griffith
  • Patent number: 6237510
    Abstract: A combustion burner includes a mixture nozzle (2) defining a mixture fluid passage through which a mixture fluid (1) containing pulverized coal and conveyor gas flows toward a furnace, secondary and tertiary air passages surrounding the mixture nozzle (2), through which secondary air (6) and tertiary air (9) for combustion purposes flow, respectively; and air injection nozzles (24) provided in the vicinity of an outer periphery of a distal end of the mixture nozzle (2). The air (21) is injected from the air injection nozzles (24) toward the axis of the mixture nozzle, so that the high-temperature gas in the vicinity of the outer periphery of the distal end of the mixture nozzle (2) is drawn into the mixture fluid (1) in the vicinity of the outer periphery of this distal end.
    Type: Grant
    Filed: March 19, 1998
    Date of Patent: May 29, 2001
    Assignee: Babcock-Hitachi Kabushiki Kaisha
    Inventors: Toshikazu Tsumura, Kenji Kiyama, Tadashi Jimbo, Shigeki Morita, Koji Kuramashi, Kunio Okiura, Shinichiro Nomura, Miki Mori, Noriyuki Ohyatsu, Noboru Takarayama, Toshihiko Mine, Hironobu Kobayashi, Hirofumi Okazaki
  • Patent number: 6234093
    Abstract: A furnace is provided for burning soila organic fuels including highly volatile organic fuels. A combustion chamber with an ash hopper has a slot mouth opening defined by slopes of the walls of the combustion chamber. A burner is disposed beneath the ash hopper mouth opening and extends across its entire width. A bottom blast inlet device generates a turbulent zone in the lower region of the combustion chamber. A duct is further provided for injecting a sulfur-absorbent material into the furnace chamber. The duct is disposed between the burner and the ash chamber and defines a longitudinal axis which traverses the turbulent zone. Preferably, the burner is tilted downwardly and is disposed on a wall in common with the sulfur-absorbent induction duct. The proportion of the sulfur-absorbent materials in the fuel mixture is in the range of 10% to 100% by mass.
    Type: Grant
    Filed: September 2, 1998
    Date of Patent: May 22, 2001
    Assignee: Polytechenergo
    Inventors: Felix Zalmanovich Finker, Igor Borisovich Kubishkin, Vitali Yurievich Zakharov, Czeslaw Sobczuk, Jan Swirski
  • Patent number: 6230635
    Abstract: A fuel selected from powder fuels and liquid fuel is ejected through a fuel ejection pipe having an annular ejection opening; primary air is ejected through primary air-ejecting openings arranged on outer and inner sides of the fuel ejection, to form outer and inner primary air-ejection straight streams between which the fuel ejection stream is interposed, and to burn the fuel ejection stream. When a powder fuel is used, optionally, a liquid fuel is further ejected and mixed with the above-mentioned primary air streams, and the liquid and powder fuels are burnt together.
    Type: Grant
    Filed: August 21, 1998
    Date of Patent: May 15, 2001
    Assignee: Sumitomo Osaka Cement Co. Ltd.
    Inventors: Katsuji Mukai, Yoshihiko Sumitani, Toshiyuki Ishinohachi
  • Patent number: 6216613
    Abstract: A process for solid fossil fuel oxidation that utilizes a refractory that defines a reactor core and a combustor chamber in serial communication. The reactor core is heated by burning an air fuel mixture external to the reactor core. A non-oxidizing gas/coal mixture is introduced into the reactor core where heat energy is transferred to the non-oxidizing gas/coal mixture so that the specific heat of the mixture is substantially raised. The non-oxidizing gas/coal mixture is discharged from the reactor core into the combustor chamber at which point an oxidizing medium such as air is introduced in order to instantly oxidize the heated non-oxidizing gas/coal mixture. The non-oxidizing gas may be a flammable gas, such as methane.
    Type: Grant
    Filed: July 2, 1999
    Date of Patent: April 17, 2001
    Assignee: Theoretical Thermionics, Inc.
    Inventor: Paul Wachendorfer
  • Patent number: 6213032
    Abstract: An in-furnace method and apparatus reduces nitrogen oxides in flue gas by injecting an oil water emulsion into flue gas so that the oil and water mixes with said flue gas. The emulsion has from 35% to 80% water and is injected in sufficient quantities to provide enough oil to promote a reaction between the nitrogen oxides in the flue gas and the oil, so as to reduce nitrogen oxide content of the flue gas and to maintain overall fuel lean conditions above the primary combustion zone. The emulsion preferably is atomized before injection and may also be injected in jet streams. Other materials such as limestone, ammonia and urea could be added to the oil water emulsion prior to injection.
    Type: Grant
    Filed: August 30, 1999
    Date of Patent: April 10, 2001
    Assignee: Energy Systems Associates
    Inventors: Bernard P. Breen, James E. Gabrielson
  • Patent number: 6202578
    Abstract: A method and reactor for processing fuels with a wide particle size distribution, particularly for flame combustion. The fuel is blown tangentially with the aid of an airflow into a swirl chamber containing a burning mass, thus creating a vortex, from the center of which a flow of material is led out of the swirl chamber. The vortex created by the feed of the fuel-air mixture and the diameter of the outlet flow are arranged to create a selective delay for coarse particles, so that the size of the particles is reduced, through mechanical treatment caused by evaporation, pyrolysis, and collision, to become smaller than the desired limit value, before they escape from the swirl chamber. The temperature of the cylindrical jacket of the swirl chamber is held below the melting point of the ash.
    Type: Grant
    Filed: March 24, 1998
    Date of Patent: March 20, 2001
    Assignee: Vapo Oy
    Inventors: Seppo Ruottu, Markku Miettinen, Mauno Oksanen
  • Patent number: 6189464
    Abstract: A combustion method utilizing a pulverized coal combustion burner which is provided with a pulverized coal nozzle for jetting a fluid mixture of pulverized coal and air and an air nozzle for jetting air. In the method, a combustion flame formed by the pulverized coal combustion burner forms a first zone of a gas phase air ratio of one or less at a radially central portion of the flame and a second zone of a gas phase air ratio of more than one outside of the first zone adjacent the coal nozzle, and a third zone of a gas phase air ratio of one or less at a downstream side from said first and second zones.
    Type: Grant
    Filed: January 28, 1999
    Date of Patent: February 20, 2001
    Assignees: Hitachi, Ltd., Babcock-Hitachi Kabushiki Kaisha
    Inventors: Hirofumi Okazaki, Hironobu Kobayashi, Toshikazu Tsumura, Kenji Kiyama, Tadashi Jimbo, Kouji Kuramashi, Shigeki Morita, Shinichiro Nomura, Miki Shimogori
  • Patent number: 6173663
    Abstract: A method of combusting pulverized coal by mixing the pulverized coal and an oxidant gas to provide a pulverized coal-oxidant gas mixture and contacting the pulverized coal-oxidant gas mixture with a flame sufficiently hot to combust the mixture. An oxygen-containing gas is passed in contact with a dense ceramic membrane of metal oxide material having electron conductivity and oxygen ion conductivity that is gas-impervious until the oxygen concentration on one side of the membrane is not less than about 30% by volume. An oxidant gas with an oxygen concentration of not less than about 30% by volume and a CO2 concentration of not less than about 30% by volume and pulverized coal is contacted with a flame sufficiently hot to combust the mixture to produce heat and a flue gas. One dense ceramic membrane disclosed is selected from the group consisting of materials having formulae SrCo0.8Fe0.2Ox, SrCo0.5FeOx and La0.2Sr0.8Co0.4Fe0.6Ox.
    Type: Grant
    Filed: June 21, 1999
    Date of Patent: January 16, 2001
    Assignee: The University of Chicago
    Inventors: Uthamalingam Balachandran, Arun C. Bose, Howard G. McIlvried
  • Patent number: 6164221
    Abstract: The invention provides a method which includes the step of locating a burner of a low NOx boiler that produces a disproportionately high quantity of unburned carbon. The air-to-fuel ratio at the burner is then increased to decrease the percentage of unburned carbon attributable to the burner. The air-to-fuel ratio at a second burner of the low NOx boiler is reduced to maintain a substantially constant total air-to-fuel ratio in the low NOx boiler.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: December 26, 2000
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Anthony Facchiano, Richard A. Brown, Wate T. Bakker, Robert R. Hardman
  • Patent number: 6152054
    Abstract: A method and system for the use of waste coal fines to reduce nitrogen oxides emissions from a coal-fired cyclone boiler. A coal water slurry including waste coal fines is injected as a co-firing fuel into a cyclone barrel of the cyclone boiler to partially oxidize the coal water slurry in a central portion of the cyclone barrel where injected. This produces a reducing zone having reducing gas species that convert nitrogen oxides to diatomic nitrogen. The coal water slurry can alternatively be injected into the cyclone barrel from a secondary combustion air conduit. The evaporation of the water from the coal water slurry reduces the overall combustion temperature in the cyclone barrel, further reducing the production of nitrogen oxides.
    Type: Grant
    Filed: October 1, 1999
    Date of Patent: November 28, 2000
    Assignee: GE Energy and Environmental Research Corp.
    Inventors: Robert A. Ashworth, W. Richard Carson, Todd A. Melick, Todd M. Sommer
  • Patent number: 6148744
    Abstract: A method of operating a pulverized coal-firing furnace so as to achieve no more than a predetermined variation in the instantaneous vertical velocities of the flow exiting a combustion chamber of the furnace is provided. The method includes, in one variation thereof, providing a series of lower compartments for introducing therethrough one of air, fuel, and air and fuel into the combustion chamber. At least one upper compartment is disposed above the topmost compartment of the series of lower compartments at a relative disposition to the topmost compartment in a spacing range between a contiguous disposition to a more spaced disposition which is no more than twice the average spacing between any given compartment and an adjacent compartment.
    Type: Grant
    Filed: September 21, 1999
    Date of Patent: November 21, 2000
    Assignee: ABB Alstom Power Inc.
    Inventors: Paul J. Chapman, John F. Drennen, Michael L. Kaplan, Majed A. Toqan
  • Patent number: 6148745
    Abstract: Method for the combustion of vanadium-containing fuels that makes use of the extremely high reactivity of the vanadium-containing fuels for combustion in a dust furnace. To avoid disadvantageous slag caking in a combustion area and in particular in the vicinity of the feed nozzles, e.g. for the pulverized fuel-air mixture and for combustion air, in a dust furnace, a top burner is placed in a roof of a combustion area and at least open dust nozzel is so positioned for the supply of the pulverized fuel-air mixture that a return flow of liquid slag particles to the top burner is prevented.
    Type: Grant
    Filed: February 17, 1999
    Date of Patent: November 21, 2000
    Assignees: Loesche GmbH, Walter Brinkmann GmbH
    Inventors: Holger Wulfert, Andre Michael Baetz, Klaus Goerner, Friedrich Schmaus
  • Patent number: 6145454
    Abstract: A furnace of a pulverized coal firing boiler includes a coutant bottom and walls intersecting with the coutant bottom and extending generally vertically therefrom to enclose and define an interior combustion chamber. A first windbox disposed in a corner of the combustion chamber includes therein a vertical array of consecutively spaced coal compartments. A coal nozzle of the lowermost coal compartment of the vertical array is disposed at least ten feet from the intersection of the walls with the coutant bottom. A second coal nozzle is disposed within a second adjacent coal compartment at a first vertical spacing to the first coal nozzle; a third coal nozzle is disposed within a third adjacent coal compartment at a second vertical spacing to the second coal nozzle; and a fourth coal nozzle is disposed within a fourth adjacent coal compartment at a third vertical spacing to the second coal nozzle.
    Type: Grant
    Filed: November 30, 1999
    Date of Patent: November 14, 2000
    Assignee: Duke Energy Corporation
    Inventor: Joseph J. Barna
  • Patent number: 6145449
    Abstract: A pulverized fuel combustion burner and furnace arrangement has a plurality of air nozzles arranged on a side wall of the furnace for injecting a mixed flow of pulverized fuel and carrier air to establish a flame into the furnace. The plurality of nozzles includes a primary nozzle for injecting the mixed flow into the furnace and a secondary nozzle positioned around the primary nozzle for feeding combustion auxiliary air around the primary nozzle. A pulverized fuel supply pipe feeds the mixed flow to the primary nozzle. The primary nozzle and the pulverized fuel supply pipe are joined at a jointed portion at which the primary nozzle can be pivoted to change a direction for injecting the mixed flow into the furnace. The pulverized fuel supply pipe extends through a windbox, the windbox forming a combustion auxiliary air supply passage around the pulverized fuel supply pipe.
    Type: Grant
    Filed: March 31, 1998
    Date of Patent: November 14, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Shouzo Kaneko, Tadashi Gengo, Kouichi Sakamoto, Takayoshi Isoda
  • Patent number: 6138588
    Abstract: A method of operating a pulverized coal-firing furnace is provided which includes injecting air from an upper compartment generally in opposition to a swirling fireball. The method also provides the step of sensing a temperature characteristic of one side of a convection pass of the furnace. The sensed value, in accordance with the method of the present invention, is then evaluated to determine if the sensed value of the temperature characteristic exceeds an allowable value. In response to a determination that the temperature characteristic exceeds the allowable value, the momentum of the air injected through the upper air compartment is changed. After the step of changing the momentum of the air injected through the upper air compartment, the temperature characteristic of the one convection pass location is sensed to obtain a post adjustment value of the temperature characteristic and compared to an allowable value.
    Type: Grant
    Filed: August 10, 1999
    Date of Patent: October 31, 2000
    Assignee: ABB Alstom Power Inc.
    Inventors: Paul J. Chapman, Michael L. Kaplan, Majed A. Toqan
  • Patent number: 6126440
    Abstract: A method and assembly is provided for modifying a regenerative or a recuperative furnace system having air-fuel burners for use with synthetic air. A portion of the exhaust gases from the furnace is recycled and mixed with oxygen gas to form synthetic air. The synthetic air is then used to support combustion in the furnace. A cassette regenerative oxy-fuel cross-fired furnace system is also provided. The cassette regenerative furnace system utilizes synthetic air containing a mixture of recycled exhaust gases and oxygen in combination with cassette regenerators.
    Type: Grant
    Filed: May 9, 1997
    Date of Patent: October 3, 2000
    Assignee: Frazier-Simplex, Inc.
    Inventors: Ronald D. Argent, Christopher J. Hoyle, Gordon Dickinson, Trevor Ward, George R. Mattocks
  • Patent number: 6119607
    Abstract: The process is conducted in an incinerator installation comprising i) a generally vertical, cylindrical riser pipe, ii) a vertically extending annular chamber surrounding the riser pipe and containing a fluidized bed of granular inert material, and iii) a burner for producing an upwardly extending flame in the lower portion of the riser pipe. Granular solid waste is supplied at a constant flow rate to the bed, directly or through the burner. Granular solid waste and bed material is transferred from the lower portion of the annular chamber to the lower portion of the riser pipe directly in the flame. The flame burns the granular solid waste, heats the inside of the riser pipe to a temperature greater than or equal to 900.degree. C.
    Type: Grant
    Filed: May 9, 1997
    Date of Patent: September 19, 2000
    Assignee: Corporation de l'Ecole Polytechnique
    Inventors: Christophe Guy, Robert Legros, Jamal Chaouki, Rene-Jean Lavallee, Luc Bussac, Luc Mauillon, Lukanda Mukadi
  • Patent number: 6101959
    Abstract: Oil shale having a relatively wide range of heating value is combusted by supplying the oil shale and a further fuel having a heating value greater than the heating value of the oil shale to a combustor. The oil shale is fed to the combustor at a substantially fixed rate, independently of the heating value of the oil shale, and the further fuel is fed to the combustor at a rate such that the heating value of the fuel in the combustor remains substantially constant in the face of variations in the heating value of the oil shale. Preferably, the temperature of combustion of the products of combustion is the parameter used to control the rate at which the further fuel is fed to the combustor.
    Type: Grant
    Filed: May 29, 1997
    Date of Patent: August 15, 2000
    Assignee: Ormat Industries Ltd.
    Inventors: Lucien Y. Bronicki, Benjamin Doron, Daniel Goldman
  • Patent number: 6101958
    Abstract: A method of and an apparatus for the thermal degradation of refuse, garbage and other waste material in which the waste material stream is reacted with air or oxygen in a reaction chamber for pyrolysis, destructive distillation or incineration of the waste material. The released thermal energy, spatial temperature distribution or outlet gas temperature is measured and used to control a feeder which supplies particles of a supplemental fuel, itself recovered from a waste material separate from the waste material stream, to the reaction chamber.
    Type: Grant
    Filed: February 19, 1998
    Date of Patent: August 15, 2000
    Assignee: Deutsche Babcock Anlagen GmbH
    Inventors: Ralf Beckmann, Arvid Christmann, Joachim Dohmann, Kai Keldenich, Rolf Kummel, Frank Niermann, Wilhelm Ruben, Johannes Seippel
  • Patent number: 6089169
    Abstract: A facility for reclaiming useful products from solid municipal and hazardous waste uses a rotary kiln to convert the material into a stream of inorganic ash and a stream of gaseous combustion products. The stream of combustion products passes in heat exchange relation to unburned waste and produces a stream of volatile carbon compounds which are deficient in oxygen. The streams of combustion products and volatile carbon compounds are converted in a plasma arc generator into a stream of hot, disassociated atoms. The stream of hot gas is cooled by passage through one or more heat exchangers that reclaim process heat. The stable compounds that are produced are hydrogen and carbon monoxide. The process is controlled by monitoring carbon dioxide in the carbon monoxide stream. The carbon monoxide and hydrogen may be used separately or combined, as in a methanol synthesis plant.
    Type: Grant
    Filed: March 22, 1999
    Date of Patent: July 18, 2000
    Assignee: C.W. Processes, Inc.
    Inventor: Eugene A. Comiskey
  • Patent number: 6089170
    Abstract: A low NOx gas combustor includes an air injection mechanism to create a combustion air path. A set of arc-shaped gas injector arrays are formed in an annular configuration. Each arc-shaped gas injector array injects an arc-shaped stream of gas that intersects with the combustion air path to produce a fuel rich flame segment that is separated from an adjacent fuel rich flame segment from an adjacent arc-shaped gas injector array by an air rich zone. The interaction between the fuel rich flame segment and the air rich zone results in low NOx combustion of the gas.
    Type: Grant
    Filed: December 17, 1998
    Date of Patent: July 18, 2000
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Anthony V. Conti, Anthony Facchiano, Dan V. Giovanni, James Lucente, Michael W. McElroy
  • Patent number: 6089171
    Abstract: A minimum recirculation flame control (MRFC) solid fuel nozzle tip (12) that is suited to being cooperatively associated with a pulverized solid fuel nozzle (34) of a firing system in a pulverized solid fuel-fired furnace (10). The MRFC solid fuel nozzle tip (12) includes a secondary air shroud (46), secondary air shroud support (50) operative for supporting the primary air shroud (48) relative to the secondary air shroud (46), and a splitter plate (52) mounted in supported relation within the primary air shroud (48).
    Type: Grant
    Filed: August 15, 1997
    Date of Patent: July 18, 2000
    Assignee: Combustion Engineering, Inc.
    Inventors: Milton A. Fong, Todd D. Hellewell, Robert D. Lewis, Charles Q. Maney, Srivats Srinivasachar, Majed A. Toqan, David P. Towle
  • Patent number: 6085673
    Abstract: A method to reduce waterwall corrosion in a low NO.sub.x boiler includes the steps of locating a waterwall area of a low NO.sub.x boiler where oxidizing conditions exist and deposition of FeS is likely. The combustion air input at the waterwall area is biased to reduce FeS deposition on the waterwall. The biased combustion air input increases the oxidation rate of FeS.sub.2 so as to reduce FeS deposition on the waterwall. The biased combustion air input may be achieved by increasing the air-to-fuel ratio of one burner while reducing the air-to-fuel ratio of another burner, such that the overall air-to-fuel ratio in the low NO.sub.x boiler is substantially constant.
    Type: Grant
    Filed: June 18, 1998
    Date of Patent: July 11, 2000
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Wate T. Bakker, Anthony Facchiano
  • Patent number: 6085674
    Abstract: A method and apparatus for reducing NO.sub.x emissions from the combustion of carbonaceous fuels using three stages of oxidation. In the first stage, a partial oxidation combustor is used to partially combust the fuel in the presence of heated combustion air. The fuel gas produced in the partial oxidation process is passed to a second stage partial oxidation combustor while molten slag is removed and disposed of. A second preheated combustion air is introduced into the second stage combustor to produce a reducing flue gas. A third combustion air is mixed with the flue gas in a third stage combustor to substantially complete the combustion process. Preheated steam may be added at any or all of the combustion stages. The stochiometric ratios at each stage of combustion are controlled to minimize overall NO.sub.x emissions to acceptable levels.
    Type: Grant
    Filed: February 3, 1999
    Date of Patent: July 11, 2000
    Assignee: Clearstack Combustion Corp.
    Inventor: Robert A. Ashworth
  • Patent number: 6082273
    Abstract: In a method for operating a corner burner of a tangential burner system, at least a first air stream of coal dust and primary air is tangentially introduced to a imaginary horizontal circle in the combustion chamber of the tangential burner system via a nozzle of the corner burner. An additional air stream is introduced into the combustion chamber in a direction toward a chamber wall of the combustion chamber at an adjustable offset angle relative to the first air stream. The offset angle can be adjusted by providing the additional air stream as mixed air stream of at least two partial air streams of different adjustable flow velocity. A first partial air stream within the nozzle flows straight into the outlet opening of the nozzle, and the second partial air stream flows angularly into the first partial air stream upstream of the outlet opening. The nozzle has a mixing chamber arranged upstream of the outlet opening.
    Type: Grant
    Filed: December 11, 1998
    Date of Patent: July 4, 2000
    Assignee: L. & C. Steinmuller GmbH
    Inventors: Werner Christ, Wolfgang Schreier
  • Patent number: 6067915
    Abstract: A method of charging a pyrolytic gas-producing reactor with waste fuel wherein the waste fuel is forced into the reactor by a ram and wherein air is prevented from entering the reactor and pyrolysis gases are prevented from escaping from the reactor by means of an ablative seal which is positioned between the fuel and the ram and which is forced by the action of the ram on the fuel charge into the reactor whilst in sealing engagement with the internal walls of the reactor, the seal being made of a material which will resist the high temperature and chemical conditions in the reactor for at least as long a period as is required for the seal to perform its sealing function and which is thereafter thermally decomposed into products which are not detrimental to the pyrolytic process or to the pyrolytic gases produced by the reactor.
    Type: Grant
    Filed: April 27, 1998
    Date of Patent: May 30, 2000
    Assignee: Compact Power Limited
    Inventor: John Ernest Elsom Sharpe
  • Patent number: 6021743
    Abstract: A steam generator achieves an especially high efficiency when biomass is used as a fuel. The steam generator contains a first combustion chamber for generating a gaseous working medium by burning a first fuel and a second combustion chamber for burning a second fuel. The second combustion chamber is connected downstream of the first combustion chamber in flow direction of the working medium. Bituminous coal may be fed as the first fuel to the first combustion chamber and/or biomass, in particular straw, may be fed as the second fuel to the second combustion chamber. The working medium generated in the first combustion chamber during operation of the steam generator serves as combustion air in the second combustion chamber.
    Type: Grant
    Filed: February 23, 1998
    Date of Patent: February 8, 2000
    Assignee: Siemens Aktiengesellschaft
    Inventor: Gunter Bauer
  • Patent number: 5992336
    Abstract: Bottom ash and flyash having high LOI is reburned in a pulverized coal furnace. The bottom ash is added to the coal supply before the coal is pulverized. Flyash is added to the pulverized coal stream for injection with the pulverized coal or is separately injected into the furnace at or slightly above the level of the coal burners in the furnace. The bottom ash and flyash is added to the coal in direct proportion of 1% to 3.5% of the coal.
    Type: Grant
    Filed: December 31, 1996
    Date of Patent: November 30, 1999
    Assignee: Wisconsin Electric Power Company
    Inventor: Bruce W. Ramme
  • Patent number: 5992335
    Abstract: A method for blowing a synthetic resin material into a furnace which comprises processing film-shaped synthetic resins into a first granular resin material; crushing non-film-shaped synthetic resins into a second granular resin material; pneumatically feeding the first granular resin material and the second granular resin material to a furnace; and blowing the first and second granular resin material into the furnace.
    Type: Grant
    Filed: March 13, 1997
    Date of Patent: November 30, 1999
    Assignee: NKK Corporation
    Inventors: Hiromi Nakamura, Iwao Okochi, Mitsuhiro Fujii, Atsushi Yamaguchi, Minoru Asanuma, Tatsuro Ariyama, Michitaka Sato, Ryota Murai, Tsuneo Nagaoka, Tetsuo Akashi, Kenichi Tezuka, Yukihiko Asakawa, Koichi Tomioka, Hiroki Ishiguro, Yutuka Yamada, Kazumasa Wakimoto, Hideaki Tsukiji
  • Patent number: 5988081
    Abstract: A method and system for the use of waste coal fines to reduce nitrogen oxides emissions from a coal-fired cyclone boiler. A coal water slurry including waste coal fines is injected as a co-firing fuel into a cyclone barrel of the cyclone boiler to partially oxidize the coal water slurry in a central portion of the cyclone barrel where injected. This produces a reducing zone having reducing gas species that convert nitrogen oxides to diatomic nitrogen. The coal water slurry can alternatively be injected into the cyclone barrel from a secondary combustion air conduit. The evaporation of the water from the coal water slurry reduces the overall combustion temperature in the cyclone barrel, further reducing the production of nitrogen oxides.
    Type: Grant
    Filed: July 22, 1997
    Date of Patent: November 23, 1999
    Assignees: Energy & Environmental Research Corporation, Tennessee Valley Authority
    Inventors: Robert A. Ashworth, W. Richard Carson, Todd A. Melick, Todd M. Sommer
  • Patent number: 5967065
    Abstract: A method and apparatus for disposing of paper in an asphalt plant. The asphalt plant comprises a container for stone aggregate to be heated, a burner for producing a burner flame to provide thermal energy for heating the stone aggregate in the container, the burner being positioned relative to the container so that an open space is defined therebetween, and a supplementary burner positioned in the open space between the burner and the container. The supplementary burner includes a supplementary burner member for producing a supplementary burner flame to provide thermal energy for heating the stone aggregate in the container, an air supply connected to the supplementary burner member for providing a stream of air to the supplementary burner member, and a supply of paper connected to the air supply for introducing paper into the stream of air. The paper is introduced into the stream of air such that the paper is entrained in the stream of air and is substantially incinerated in the container.
    Type: Grant
    Filed: February 9, 1998
    Date of Patent: October 19, 1999
    Inventor: Thomas R. Amon
  • Patent number: 5960724
    Abstract: A method for effecting control over a radially stratified flame core burner that is particularly suited for employment in a firing system of a fossil fuel-fired furnace for purposes of reducing the NO.sub.X emissions from the fossil fuel-fired furnace. The subject method for effecting control over a radially stratified flame core burner enables the foregoing to be accomplished while yet at the same time minimizing CO emissions and the opacity of the exhaust from the stack of the fossil fuel-fired furnace without extending the envelope of the flame produced by the radially stratified flame core burner.
    Type: Grant
    Filed: July 27, 1998
    Date of Patent: October 5, 1999
    Inventors: Majed A. Toqan, Richard W. Borio, Thomas G. Duby, Richard C. LaFlesh, Julie A. Nicholson, David E. Thornock
  • Patent number: 5937772
    Abstract: A process and apparatus for combustion in which a combustible material is introduced into a combustion chamber and oxidant is supplied to the combustion chamber. The combustible material is burned, and forming a primary combustion zone. A mixture of flue gases and flyash having an organic content is injected into the combustion chamber downstream of the primary combustion zone to create an oxygen-deficient reburn zone, thereby lowering the temperature of combustion, reducing the NO.sub.x content of the flue gases, and reducing the potential for NO.sub.x formation in a tertiary oxidizing combustion zone disposed downstream of the oxygen-deficient reburn zone.
    Type: Grant
    Filed: July 30, 1997
    Date of Patent: August 17, 1999
    Assignee: Institute of Gas Technology
    Inventors: Mark J. Khinkis, Iosif K. Rabovitser, Michael J. Roberts
  • Patent number: 5934206
    Abstract: The water jacket face of a burner nozzle for a synthesis gas generator is protected from hot gas corrosion by an annular heat shield of high temperature material tiles. Six, for example, angular segments of a tile annulus around a burner nozzle orifice are secured to the water jacket face by furnace melted, high temperature brazed metal. The metal water jacket face along radial joints between adjacent tiles is protected by stepped or scarfed lap joints.
    Type: Grant
    Filed: April 7, 1997
    Date of Patent: August 10, 1999
    Assignee: Eastman Chemical Company
    Inventors: Daniel Isaiah Saxon, Stacey Elaine Swisher, Gary Scott Whittaker
  • Patent number: 5908003
    Abstract: A process and apparatus for combustion of a solid carbonaceous material, for example coal, in which a mixture of the solid carbonaceous material and combustion air is injected into a combustion chamber and ignited, thereby forming a fuel-lean primary combustion zone. A gaseous fuel is injected into the combustion chamber in a region downstream of the primary combustion zone, thereby forming a fuel-lean secondary combustion zone. Temperature in the secondary combustion zone is in the range of about 1800.degree. F. to 2400.degree. F.
    Type: Grant
    Filed: August 8, 1997
    Date of Patent: June 1, 1999
    Assignee: Gas Research Institute
    Inventors: Harjit S. Hura, Bernard P. Breen
  • Patent number: 5899172
    Abstract: A separated overfire air injection system particularly suited for use in a fossil fuel-fired steam generating power plant and more specifically to a sixpoint separated overfire air tangential firing system employed in such power plants, particularly those embodying dual-chambered furnaces. A method of operating such a fossil fuel-fired steam generating power plant equipped with the sixpoint separated overfire air injection system of the present invention is also disclosed. The separated overfire injection system in accordance with the present invention includes six SOFA windboxes strategically located about the perimeter of the dual-chambered furnace volume so as to be operative to inject separated overfire air into the furnace volume in such a manner as to engage a fireball symmetrically tangential to a circle.
    Type: Grant
    Filed: April 14, 1997
    Date of Patent: May 4, 1999
    Assignee: Combustion Engineering, Inc.
    Inventors: John V. Dallen, Steven B. Fothergill
  • Patent number: 5890444
    Abstract: For determining the average radiation of a surface region of a burning bed, an infrared camera is used in a firing installation, which camera is aligned with this region and is equipped by means of appropriate flame filters in such a way that it operates at the minimum of the interfering radiation emanating from the flame, whereby this interfering radiation is already largely eliminated. In order then also to eliminate the solids radiation from moving particles and thus to obtain a temperature measurement of the burning bed, recordings are made successively at short intervals of time by means of the infrared camera and these are evaluated in the evaluation and control device.
    Type: Grant
    Filed: July 29, 1998
    Date of Patent: April 6, 1999
    Assignee: Martin GmbH fuer Unwelt- und Energietechnik
    Inventors: Johannes Martin, Walter Martin
  • Patent number: 5868083
    Abstract: To a fluidized combustor bed there is passed particulate fuel via a fuel flow distributor which comprises a vessel for receiving a particular fuel from a fuel storage. The fuel is fed into the vessel of the fuel flow distributor from the fuel storage, whereupon the fuel is fluidized in a bed above a bed bottom in the vessel of the fuel flow distributor. The fuel flow distributor comprises at least two feed pipes with associated inlets located adjacent the surface of the bed in the fuel flow distributor, where fluidization gas which leaves the vessel via a feed pipe feeds out fuel to at least one nozzle is in the bed of the combustor. Additional gas is supplied to the feel pipes at the inlets thereof, such that the flow of fuel through an individual feel pipe can be controlled by controlling the gas flow supplied to the inlets of the respective feed pipes.
    Type: Grant
    Filed: March 27, 1997
    Date of Patent: February 9, 1999
    Assignee: ABB Carbon AB
    Inventors: Roine Brannstrom, Carl Johan Sandelin
  • Patent number: 5862762
    Abstract: Combustible is comminuted and dried, and metal and noncombustible are removed from the coarsely comminuted combustible. Then, the combustible is secondarily comminuted and separated into coarse combustible and fluff which is fine combustible. The coarse combustible of the separated combustible is fed onto a fire grate (2) of a refuse incinerator (1), and burned in flat bed combustion in a primary combustion chamber (4). On the other hand, the fluff is burned in suspended combustion in a secondary combustion chamber (7) with a combustion fluff burner (5) for incinerating combustible. Thus, refuse containing much plastics which is formed into fluff can be efficiently disposed of, whereby the amount of incineration is increased as a whole.
    Type: Grant
    Filed: January 8, 1997
    Date of Patent: January 26, 1999
    Assignee: Hitachi Zosen Corporation
    Inventors: Yoshitoshi Sekiguchi, Kunio Sasaki, Hideo Shimotani, Noboru Okigami, Hiroshi Isotani, Kenji Kaketa, Kenji Kashiwabara, Shozo Umemura, Hiroshi Onishi
  • Patent number: 5857421
    Abstract: Combustible gases from a solid fuel are produced by pyrolyzing the fuel in a pyrolyzer which also produces carbonaceous material. The carbonaceous material from the pyrolyzer is combusted in a furnace to produce combustion products that include hot flue gases and ash particulate. The combustion products are separated into a plurality of streams, one of which contains flue gases, and another of which contains hot ash which is directed into the pyrolyzer. Finally, the stream of flue gases from the furnace is used to dry the fuel that is supplied to said pyrolyzer.
    Type: Grant
    Filed: April 8, 1996
    Date of Patent: January 12, 1999
    Assignee: Ormat, Inc.
    Inventors: Benjamin Doron, Daniel Goldman, Eli Yaffe
  • Patent number: 5832847
    Abstract: The process for combustion of coal dust with combustion air in burners and for reducing the production of NO.sub.x during the combustion. Combustion air is fed to the burners in form of primary air and secondary air. The burners are supplied coal dust through the primary air in a mixture of coal dust and primary air. A primary gas is generated with combustible gaseous components from the mixture of coal dust and primary air, through pyrolysis of the coal dust in the ignition region of the burners. In the ignition region, there is lowered the mean ratio of oxygen components in the primary gas to the oxygen amount required to burn freely released combustible gaseous components of the primary gas by reducing the oxygen component in the primary gas and/or injecting the primary gas with a combustible external gas.
    Type: Grant
    Filed: June 19, 1996
    Date of Patent: November 10, 1998
    Assignee: Babcock Lentjes Kraftwerkstechnik GmbH
    Inventors: Alfons Leisse, Michael Streffing
  • Patent number: 5829368
    Abstract: The fuel is fed into a circulating fluidized bed steam generator using a feed system involving an air swept chute using secondary combustion air to suspend and carry the fuel into the fluidized bed combustor. The fuel is fed to the air swept chute through a gravity feed chute at a steep angle. The air swept chute is lined with an abrasion resistant material.
    Type: Grant
    Filed: December 31, 1996
    Date of Patent: November 3, 1998
    Assignee: Combustion Engineering, Inc.
    Inventors: Gary A. Cote, Paul J. Panos
  • Patent number: 5829369
    Abstract: A burner having lower emissions and lower unburned fuel losses by implementing a transition zone in a low NO.sub.x burner. The improved burner includes a pulverized fuel transport nozzle surrounded by the transition zone which shields the central oxygen-lean fuel devolatilization zone from the swirling secondary combustion air. The transition zone acts as a buffer between the primary and the secondary air streams to improve the control of near-burner mixing and flame stability by providing limited recirculation regions between primary and secondary air streams. These limited recirculation regions transport evolved NO.sub.x back towards the oxygen-lean fuel pyrolysis zone for reduction to molecular nitrogen. Alternate embodiments include natural gas and fuel oil firing.
    Type: Grant
    Filed: November 12, 1996
    Date of Patent: November 3, 1998
    Assignee: The Babcock & Wilcox Company
    Inventors: Jennifer L. Sivy, Larry W. Rodgers, John V. Koslosy, Albert D. LaRue, Keith C. Kaufman, Hamid Sarv
  • Patent number: 5809912
    Abstract: A heat exchanger and a fluidized bed combustion system and method utilizing same in which the heat exchanger includes a plurality of stacked sections. The sections include an inlet section for receiving the particles and a plurality of stacked sections and are arranged in such a manner that the particles are introduced into an upper level of the sections and pass through these sections to a lower level of sections before returning to the furnace. A portion of the stacked sections contain heat exchange surfaces for removing heat from the particles, and a multi-sectioned outlet compartment is provided to receive the separated particles from the heat exchange sections and directly from the inlet section and pass the particles back to the furnace.
    Type: Grant
    Filed: June 11, 1996
    Date of Patent: September 22, 1998
    Assignee: Foster Wheeler Energy, Inc.
    Inventors: Arthur Magne Hansen, Stephen John Goidich
  • Patent number: 5809913
    Abstract: A method for reducing the rate of side wall corrosion in a coal-fired utility boiler. A plurality of side wall slots are provided in the side walls of the boiler so that a protective layer of air may be introduced through the slots and propelled upward by the updraft from the burners.
    Type: Grant
    Filed: October 15, 1996
    Date of Patent: September 22, 1998
    Assignees: Cinergy Technology, Inc., Energy Systems Associates
    Inventors: Edward D. Kramer, Joseph A. Urich, Keith S. Lochart, Bernard P. Breen, James E. Gabrielson
  • Patent number: 5799594
    Abstract: Method for combusting pulverized fuels in a tangentially fired boiler and reducing emission of nitrogen oxides comprises steps of feeding a substantially air-deficient mixture of fuel and primary air through a fuel feeding pipe (1) tangentially into a furnace of the boiler in order to form a reducing flame (II) aNd blowing of at least one stream of combustion air into the furnace. The invEntion is based in that the stream of primary air and fuel is caused to recirculate and turbulate at the open end (2) of the fuel feeding pipe (1) by passing it through a flame holder (9) extending into the fuel feeding pipe (1), and the stream of combustion air is directed away from the primary air/fuel stream in order to prevent the combustion air to mix into the reducing flame (II).
    Type: Grant
    Filed: May 2, 1996
    Date of Patent: September 1, 1998
    Assignee: IVO International Oy
    Inventors: Pauli Dernjatin, Kati Savolainen, Juha Lepikko
  • Patent number: 5794549
    Abstract: Information relating to combustion conditions within a fossil-fueled boiler that includes a plurality of burners adapted to produce flames combining to form a fireball is provided by acquiring data relating to the physical and temperature characteristics of the fireball with at least one imaging camera having optical and temperature measuring capabilities; receiving, storing and processing data received from the camera to provide data representative of the NO.sub.x content of the hot gases produced by the fireball; and transmitting the processed data from the processor to a monitor for display. Transmitted, processed data may include current, historical and target information relating to the physical appearance and temperature profile of the fireball.
    Type: Grant
    Filed: January 25, 1996
    Date of Patent: August 18, 1998
    Assignee: Applied Synergistics, Inc.
    Inventor: Hudson R. Carter
  • Patent number: 5771823
    Abstract: A method and apparatus retrofitted to a multiple-intertube pulverized-coal burner to reduce NO.sub.x emissions of roof fired boilers. An internal two stage process controls the amount of secondary air which flows to the burner. The first stage includes a secondary air damper and air flow station to regulate the amount of air which flows into a windbox of the burner. A baffle plate assembly which includes a plurality of baffle plates further limits the amount of air which flows to the core of the burner for combustion of the fuel. The baffle plates create a pressure drop within the windbox which forces or diverts a quantity of air to the periphery of the burner. The second stage includes an outlet formed in the hot primary air duct, an air plenum which communicates therewith, and a plurality of interjectory air ports which correspond with the burners in number and position along a front wall of the boiler and which communicate with the air plenum.
    Type: Grant
    Filed: January 31, 1996
    Date of Patent: June 30, 1998
    Assignee: AEP Resources Service Company
    Inventors: Scott A. Vierstra, John J. Letcavits
  • Patent number: 5769008
    Abstract: The low-emission swirling-type furnace is designed to burn organic fuel and it can be most advantegeously used for dust combustion.A low-emission swirling-type furnace, according to the invention, comprises a combustion chamber (1) with a prismatic dry-bottom hopper (5) having a slot mouth, and an undergrate blast inlet means (7) disposed thereunder. The furnace includes at least one burner (2) formed by at least a pair of ducts (2a,2b ) lying one above the other and intended for supplying the air-fuel mixture. The ducts (2a, 2b) are each provided with a device (3, 4) for controlling the "air/fuel" ratio, ensuring such a ratio between the amount of air and the amount of fuel in each of the ducts (2a,2b ) that for the overlying duct (2a), this ratio turns out to be invariably higher than for the underlying duct (2b).
    Type: Grant
    Filed: August 28, 1996
    Date of Patent: June 23, 1998
    Assignee: Maloe Gosudarstvennoe Vnedrencheskoe Predpriyatie "Politekhenergo"
    Inventors: Felix Zalmanovich Finker, Javad Berovich Akhmedov, Igor Borisovich Kubishkin, Czeslaw Sobczuk, Jan Swirski, Mark Semenovich Glazman