Means For Pulverizing Solid Fuel Patents (Class 110/232)
  • Patent number: 5269472
    Abstract: A waste processing system in which containerized waste is received substantially at ground level and is conveyed to an elevator which carries the containerized waste to an upper level discharger which transports the containerized waste, dumps the containers down a drop chute and returns the empty containers to ground level. The dumped waste is shredded and is either injected into an incinerator or is discharged downwardly. The entire system is enclosed and can be maintained at either a negative or positive pressure for receiving radioactive or hazardous wastes, or at a reduced oxygen environment for receiving flammable hazardous waste. Containerized waste is received through air locks which include sliding doors that are supported entirely about the peripheries when sealed for purposes of explosion resistance. The injector discharge tube includes a slide box in which a pair of conduit segments are mounted and can be positioned such that one or the other of the segments is connected to the output conduit.
    Type: Grant
    Filed: May 26, 1992
    Date of Patent: December 14, 1993
    Inventor: Larry E. Koenig
  • Patent number: 5251383
    Abstract: Apparatus for disposing of wet sludge by conversion to a substantially dry product during grinding of the wet sludge in a drying atmosphere which promotes the separation of the grindings into coarse fractions and fine fractions so that the coarse fractions in the dried condition can be directed to enter the supply of the wet sludge for reducing the moisture content to prepare the mix of wet sludge and coarse fractions for grinding in a drying heat atmosphere to perpetuate the supply of coarse fractions for moisture reduction of the wet sludge and a supply of the fine fractions as a product of the apparatus.
    Type: Grant
    Filed: July 6, 1992
    Date of Patent: October 12, 1993
    Inventor: Robert M. Williams
  • Patent number: 5241915
    Abstract: An apparatus and method to improve pulverizer operation and reduce nitrogen oxide emissions from furnaces which burn pulverized coal from at least one pulverizer. A duct type burner burns a fuel in the primary air which heats the primary air supplied to the pulverizers. The combustion increases the primary air temperature and improves the drying of the coal, thus improving the pulverizer throughput and/or the fineness of the pulverized coal. Operation of the duct burner also reduces the oxygen in the primary air. The reduction in oxygen reduces the propensity of the coal to ignite in the pulverizers and cause fires or even explosions. The reduced oxygen in the primary air also reduces NO.sub.x formation.
    Type: Grant
    Filed: August 10, 1992
    Date of Patent: September 7, 1993
    Assignee: Consolidated Natural Gas Service Company, Inc.
    Inventors: Bernard P. Breen, James E. Gabrielson, John Bjerklie
  • Patent number: 5239936
    Abstract: System and method for low temperature treatment of organic wastes containing potentially toxic concentrations of metals is described which comprises forming the waste material into pellets of preselected size, mixing the pellets with inert material, incrementally heating the mixture in air from about 200.degree. C. to about 600.degree. C. in order to oxidize the pellets to the corresponding ash containing the metals, collecting the ash, and combining the ash with inert material and binder to form a solidified compact for disposal.
    Type: Grant
    Filed: July 27, 1992
    Date of Patent: August 31, 1993
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Robert P. Wichner, Roger D. Spence, Ivan L. Morgan, Helen W. Jermyn
  • Patent number: 5233932
    Abstract: A shredding and feeding system for an incinerator, wherein a shredding chamber is isolated from atmosphere by means of an airlock through which material to be incinerated passes into the shredding chamber. The oxygen content of the shredding chamber is maintained below a predetermined level to minimize risk of explosions and premature incineration of material.
    Type: Grant
    Filed: January 21, 1992
    Date of Patent: August 10, 1993
    Assignee: Ensco, Inc.
    Inventor: James C. Robertson
  • Patent number: 5231939
    Abstract: This invention relates to an in-ash unburned component estimating device for a coal-fired furnace which monitors the density of in-ash unburned component contained in burning waste gases to operate the furnace efficiently. The object of the invention is to infer and estimate from the current situation by a simple means the density of in-ash unburned component in the burning exhaust gases that affects the combustion efficiency. A furnace temperature, a load band in the furnace, a furnace contamination coefficient, a ratio of two-stage combustion air supplied to the furnace, and a coal mixture ratio are taken in as fuzzy quantities to infer fuel ratio data and correction data used to correct predetermined reference values of reference in-furnace temperature distribution, reference in-furnace air ratio distribution and reference powdered coal grain diameter distribution.
    Type: Grant
    Filed: January 30, 1992
    Date of Patent: August 3, 1993
    Assignee: Kawasaki Jukogyo Kabushiki Kaisha
    Inventors: Shinji Tanaka, Tatsuya Miyatake, Kazuyoshi Yamamoto, Yuichi Miyamoto, Eiichi Harada
  • Patent number: 5217173
    Abstract: A waste processing system in which containerized waste is received substantially at ground level and is conveyed to an elevator which carries the containerized waste to an upper level discharger which transports the containerized waste, dumps the containers down a drop chute and returns the empty containers to ground level. The dumped waste is shredded and is either injected into an incinerator or is discharged downwardly. The entire system is enclosed and can be maintained at a negative pressure for receiving radioactive wastes, or at a reduced oxygen environment for receiving flammable hazardous waste. Containerized waste is received through air locks which include vertically sliding doors that are supported entirely about the peripheries when sealed for purposes of explosion resistance. The injector discharge tube includes a slide box in which a pair of conduit segments are mounted and can be positioned such that one or the other of the segments is connected to the output conduit.
    Type: Grant
    Filed: February 5, 1992
    Date of Patent: June 8, 1993
    Inventor: Larry E. Koenig
  • Patent number: 5215017
    Abstract: A fuel feed system and method for feeding low grade fuels to a fluidized bed furnace including an enclosure with a fuel inlet for introducing the fuel into the enclosure, an inlet for introducing air into the enclosure so as to propel the fuel through the enclosure, and baffles disposed in the path of the fuel in a manner to reduce the size of the fuel particles prior to the introduction of the fuel into the furnace.
    Type: Grant
    Filed: January 27, 1992
    Date of Patent: June 1, 1993
    Assignee: Foster Wheeler Energy Corporation
    Inventor: John T. Tang
  • Patent number: 5197398
    Abstract: Processes and arrangements that provide for the separation of pyrite from coal in a fluidized bed. The processes provide for more efficient and complete stratification of the bed materials in a vertical direction, so that the very top layer of the fluidized ved is coal having a reduced pyrite content. The process includes feeding the coal to be cleaned on top of a layer of magnetite. The process also includes fluidizing the bed until bed-bubbling separation occurs in the absence of steady-state conditions. The cleaned top layer of coal having a reduced pyrite content is then separated from the refuse coal in the bottom of the bed.
    Type: Grant
    Filed: April 16, 1991
    Date of Patent: March 30, 1993
    Assignee: Electric Power Research Institute
    Inventors: Edward K. Levy, D'Agostini Mark, Damir Latkovic, James W. Parkinson
  • Patent number: 5189964
    Abstract: A continuous fluidized-bed combustion process for particulate carbonaceous feedstock of high ash content. The feedstock fuel is prepared from culm or mine tailings washed in a dense media and crushed to yield a fuel product having an ash content in a range of about 30 percent to about 50 percent, by weight. The feedstock fuel is mixed with fine particles of scavenging material, such as limestone or dolomite, and the resulting feedstock mixture is burned in a circulating fluidized-bed combustion chamber. A portion of the ash remaining after combustion is discharged out the bottom chamber, the remainder being carried with the combustion gases through a hot cyclone and heat exchangers for generating power. The ash within these gases is separated and recirculated through the fluidized bed, and the combustion gases are discharged.
    Type: Grant
    Filed: April 30, 1990
    Date of Patent: March 2, 1993
    Inventor: John W. Rich, Jr.
  • Patent number: 5170728
    Abstract: A waste treatment furnace comprises a crucible equipped with heating means, a waste intake duct opening into the bottom of the crucible, a duct for removing matter from a bath opening into the crucible at a level above the level of the opening of the waste intake duct, the upper part of the furnace defining a chamber which communicates at the top with a duct for the effluent gases, an inlet ramp for a flushing gas opening into the combustion chamber.
    Type: Grant
    Filed: March 25, 1991
    Date of Patent: December 15, 1992
    Assignee: Indra S.A.
    Inventor: Rene Tanari
  • Patent number: 5158024
    Abstract: This invention relates to a combustion control apparatus for a powdered coal-fired furnace that monitors noxious substances contained within the burning waste gases, unburned substances within the ash and the power data of a pulverizing mill in order to operate the combustion furnace safely and efficiently. The combustion control apparatus infers from the current states or data optimal control amounts that will maintain within the minimum allowable ranges the noxious nitrogen oxides and the in-ash unburned substances that affect the combustion efficiency-and thereby controls the combustion furnace with good stability. The combustion control apparatus qualitatively evaluates as fuzzy quantities the density data of the nitrogen oxides contained within the exhaust gases of the unburned substances contained within the ash, and the power data of the pulverizing mill.
    Type: Grant
    Filed: January 2, 1992
    Date of Patent: October 27, 1992
    Assignee: Kawasaki Jukogyo Kabushiki Kaisha
    Inventors: Shinji Tanaka, Tatsuya Miyatake, Kazuyoshi Yamamoto, Yuichi Miyamoto
  • Patent number: 5140916
    Abstract: A system and apparatus is disclosed for delivering fuel to a furnace using an inert gas medium which has acquired moisture from the application of the furnace stack gas for drying the incoming fuel material during the reduction of the fuel to a desired size for combustion in the furnace. The use of an oxygen deficient inert gases medium as a propellant to deliver the fuel to the furnace is augmented by supplying air to the furnace to establish a staged combustion environment in the furnace to avoid the generation of high levels of the pollutant nitrous oxide which is understood to be generated by high flame temperatures and with high oxygen and nitrogen concentrations.
    Type: Grant
    Filed: December 9, 1991
    Date of Patent: August 25, 1992
    Inventor: Robert M. Williams
  • Patent number: 5099771
    Abstract: Apparatus and process for the complete breaking down and incineration of tires and other difficult-to-dispose-of-waste products in an energy-efficient manner. Small particles of the waste material are directed into a furnace of novel design. Within the furnace, the particles are incinerated and thereby converted to combustion gas products. The combustion gas products exiting from the furnace are then transferred to an energy recovery/utilization means, such as a boiler. The small particles are specifically directed into a coiled ignition tube located completely within the furnace. As the particles travel in a downwardly spiraling motion through the ignition tube they come in contact with its heat-conducting interior walls. By forcing the particles to contact the interior walls, the ignition tube of the present invention leads to an efficient incineration of those particles.
    Type: Grant
    Filed: March 21, 1991
    Date of Patent: March 31, 1992
    Inventor: Rocco J. DiSanto, Sr.
  • Patent number: 5095827
    Abstract: Apparatus for preparing in a circulating fluid bed boiler fuel material that is fed to the boiler with a moisture content that is normally high enough to plug grinding apparatus needed to grind the fuel material to a particulate size for combustion, operating the boiler and grinding apparatus in cooperation so that heat energy at a high temperature is borrowed from the boiler for drying the fuel material at the grinding apparatus and returning the heat energy in the form of steam so there is no net loss of heat energy.
    Type: Grant
    Filed: March 5, 1991
    Date of Patent: March 17, 1992
    Inventor: Robert M. Williams
  • Patent number: 5069145
    Abstract: Plastic and similar shreddable materials are reduced to small particles and pneumatically conveyed to the combustion space of a marine boiler for inceneration to dispose of such materials aboard ship. A granulator apparatus reduces the material to particulates having a maximum particle size of about 0.50 inches for conveyance by the pneumatic conveyor through a conduit which has penetrated a boiler wall in the vicinity of the combustion space.
    Type: Grant
    Filed: December 5, 1990
    Date of Patent: December 3, 1991
    Assignee: Atlantic Richfield Company
    Inventor: William M. Croke
  • Patent number: 5022328
    Abstract: A shredding and feeding system for an incinerator wherein a shredding chamber is isolated from atmosphere by means of an airlock through which material to be incinerated passes into the shredding chamber. The oxygen content of the shredding chamber is maintained below a predetermined level to minimize risk of explosions and premature incineration of material.
    Type: Grant
    Filed: August 16, 1990
    Date of Patent: June 11, 1991
    Assignee: Ensco, Inc.
    Inventor: James C. Robertson
  • Patent number: 4998485
    Abstract: An apparatus arrangement in a system for circulating an inert fluid medium in a substantially closed and inert atmosphere during the grinding of wet gob to prevent spontaneous combustion and the initiation of fire from sparks created during grinding of moisture bearing waste material. The apparatus combines with a grinding mill a fluid circulating circuit with the grinding mill to separate ground particulate gob from the circulating fluid medium, and a second fluid circulating circuit in association with a boiler to burn the ground gob material for creating an oxygen deficient atmosphere in the fluid circulating circuit.
    Type: Grant
    Filed: August 1, 1990
    Date of Patent: March 12, 1991
    Inventor: Robert M. Williams
  • Patent number: 4995324
    Abstract: A system for recovery of the heat value of waste material, that heretofore has been wasted through landfill disposal, but in which the collected bales of waste material are passed through a bale breaker to release the waste material into a free condition so it can moved in a free flowing stream into a conveyor-type storage unit for movement to a grinder which reduces the mix of waste material to a substantially uniform particle size prior to being air moved into a boiler for recovery of the heat value which on burning produces steam to drive a generator to produce electrical power for energizing the power consumers in the system, with any excess being fed to an external power grid.
    Type: Grant
    Filed: July 16, 1990
    Date of Patent: February 26, 1991
    Inventor: Robert M. Williams
  • Patent number: 4993332
    Abstract: A hybrid combustion system is provided combining advantages of a fluidized bed combustion portion and a pulverized coal combustion portion. The former portion includes a fluidized bed chamber, a coal mill without an air separator, a recycling duct connected to the coal mill, a coal supply duct, and a spray feeder. The fluidized coal combustion portion includes a pulverizing coal mill with air separator, a blowing duct for blowing ground coal, at least one pulverized coal burner and an air recycling duct for recycling combustion air. Fluidized bed combustion takes place in a lower part of the system and pulverized coal combustion takes place above the fluidized bed combustion. Each of the portions may be independently operated of the other. A main combustion chamber is common to both the fluidized bed portion and the pulverized coal portion. A related process is also described.
    Type: Grant
    Filed: September 13, 1989
    Date of Patent: February 19, 1991
    Assignees: Villamosenergiapari Kutato Intezet, Tatabanyai Hoeromu Vallalat
    Inventors: Laszlo Boross, Sandor Kovacs, Karoly Remenyi, Pal Resch, Laszlo Voros, Ferenc Horvath, Tibor Gerlai
  • Patent number: 4993323
    Abstract: An environmentally acceptable and effective method for thermal destruction of Spent Potliner (SPL) by Fluidized Bed Combustion (FBC) has been established. This method has overcome problems associated with ash agglomeration, ash leachate character and emission control, the primary obstacles for applying FBC to the disposal of SPL and like solid fuels. Specifically, "recipes" of appropriate additives (fuel blends) are proposed. A mixture of lignite, limestone and SPL in an appropriate proportion has proven to notably increase the agglomeration temperature of the ash, allowing this low-melting waste to be destroyed continuously by FBC. Ash leachate character is modified by control of ash chemistry to ensure that fluoride anions and metallic cations are at or below acceptable limits.
    Type: Grant
    Filed: May 1, 1989
    Date of Patent: February 19, 1991
    Inventors: Ronald S. Tabery, Ky Dangtran
  • Patent number: 4885999
    Abstract: The invention relates to a method of and an equipment for firing pulverized coal, and is suitable when applied to pulverized coal burning boilers or the like. In a conventional pulverized coal burning boiler, it is impossible to directly ignite the pulverized coal by an igniter, because the pulverized coal concentration in pulverized coal-air mixture fed to burner sections (20) at the early stage of the start-up is low. By this reason, precombustion due to auxiliary fuel such as oil or the like is necessary, and there is a danger of explosion within a furnace. In the invention, the mixture is circulated through a circulation passage (52, 56, 55), thereby raising the pulverized coal concentration in the mixture fed to the burner sections (20) at the start-up, to a level equal to or higher than a stable ignition concentration.
    Type: Grant
    Filed: April 20, 1988
    Date of Patent: December 12, 1989
    Assignee: Babcock-Hitachi Kabushiki Kaisha
    Inventors: Akira Baba, Kunio Okiura, Naoki Fujiwara
  • Patent number: 4798342
    Abstract: The apparatus operates to supply the air requirements for grinding a fuel material to the mill to guarantee the correct particle size and to decouple from the air emitted from the grinding apparatus a certain proportion so the combustion of the ground fuel material will be conducted at a ratio of less than the usual 3 to 1 ratio of air-to-fuel so the combustion can be controlled to reduce the nitrous oxide emission, the air that is decoupled is returned to the grinding apparatus with a supply of make up air that is heated for purposes of drying the material in the grinding apparatus.
    Type: Grant
    Filed: January 11, 1988
    Date of Patent: January 17, 1989
    Assignee: Williams Patent Crusher and Pulverizer Company
    Inventor: Robert M. Williams
  • Patent number: 4767315
    Abstract: The bed depth in a power plant burning sulfur-containing fuel in a fluidized bed of material which constitutes a sulfur absorbent in a combustion chamber is controlled on the basis of plant power output. A plurality of sensors connected to the combustion chamber determine the existing bed depth. A bed material mill grinds material removed from the bed prior to returning it to the bed, the rate at which the mill operates being controlled by the extent to which the actual bed depth differs from the desired bed depth. The mill grinds some bed material to small enough size for it to be carried from the combustion chamber with the combustion gases.
    Type: Grant
    Filed: October 10, 1986
    Date of Patent: August 30, 1988
    Assignee: Asea Stal Aktiebolag
    Inventors: Roine Brannstrom, Lars-Erik Karlsson, Martin Mansson
  • Patent number: 4763585
    Abstract: A process for the combustion of ground, spent potlinings generated during the production of metallic aluminum is disclosed. The process includes: grinding the potlinings to a particle size of not greater than about 2 inches in any dimension; mixing with the ground potlinings from about 1 to about 20 weight percent, based upon the weight of the potlinings, of a powdered inert additive having a median particle size of not greater than 10 micrometers, and burning the ground potlinings in a combustor at a temperature in the range of from 1400.degree. F. to about 2200.degree. F., the additive coating the ground potlinings and preventing their agglomeration in the combustion zone therein.
    Type: Grant
    Filed: September 8, 1987
    Date of Patent: August 16, 1988
    Assignee: Ogden Environmental Services
    Inventors: William S. Rickman, James L. Kaae, Bernard W. Gamson
  • Patent number: 4750436
    Abstract: In order to create a technically more effective and more economical method of decontamination by which complete decomposition of all injurious substances is obtained in simple fashion, it is proposed, in connection with a method and a plant for the treatment of contaminated soils, that the drying can be combined in a mill passed through by hot gases with a crushing of the material to a particle size of 0 to 10 mm, that after the drying the material, together with the gaseous phase, be treated in the form of a solid/gas dispersion in a heating and decontamination path with burner, with a temperature within the range of 800.degree. C. to 1200.degree. C.
    Type: Grant
    Filed: July 10, 1987
    Date of Patent: June 14, 1988
    Assignee: O&K Orenstein & Kopel
    Inventors: Hans-Dietmar Maury, Wolfgang Buslowski, Bernold Kraft
  • Patent number: 4702180
    Abstract: A pulverized coal burner device capable of ensuring stabilized combustion of pulverized coal even when mill load is low.
    Type: Grant
    Filed: March 24, 1987
    Date of Patent: October 27, 1987
    Assignee: Ishikawajima-Harima Jukogyo Kabushiki Kaisha
    Inventor: Takashi Kiga
  • Patent number: 4640204
    Abstract: A fluidized bed combustion apparatus in which the combustion chamber has a dense fuel bed created in the chamber, and a grinding mill connected to the dense fuel bed portion of the chamber and so operated as to classify the material into fine and coarse particulates with the fines being directed into the bottom of the dense fuel bed and the coarse particulates being directed to the top of the dense fuel bed. The apparatus is placed under the control of a controller which regulates the mill to feed fines and coarse particulates in proportions for maintaining optimum average particle size and hence optimize boiler efficiency.
    Type: Grant
    Filed: June 9, 1986
    Date of Patent: February 3, 1987
    Assignee: Williams Patent Crusher and Pulverizer Company
    Inventor: Robert M. Williams
  • Patent number: 4635572
    Abstract: A process and devices with which the fused sulphur is removed from fossil fuels, preferably coke and petrocoke, ahead of the furnace or the like and is fused with an additive. In the combustion chamber, the additive with the fused sulphur is then sintered. The fuel is desulphurized at a temperature management controllable by an electronic process computer, at controllable residence times and pressure conditions in leading zones so that practically completely desulphurized fuel is burned in the combustion chamber. The sulphur components are removed with the additive via an ash removal plant. A combustion of the sulphur components of the fuel to SO.sub.2 within the combustion chamber does not occur.
    Type: Grant
    Filed: March 11, 1985
    Date of Patent: January 13, 1987
    Assignee: Kasa-Technoplan GmbH
    Inventor: Klaus-Dietrich Nickel
  • Patent number: 4628830
    Abstract: A microwave transmitter irradiates each outlet pipe flow path of a coal pulverizer with a beam of electromagnetic energy at a microwave frequency. The microwave energy absorbed in each outlet pipe flow path is monitored and is proportional to the pulverized fuel flow therethrough. Knowing the fuel flow rate into the pulverizer, the fuel flow rate through each outlet pipe flow path may be determined. The portion of pulverized fuel flow exiting the pulverizer through a given pipe is determined as the ratio of microwave energy absorbed in each outlet pipe flow path to the average microwave energy absorbed in all outlet pipe flow paths of the pulverizer, multiplied by the fuel flow rate into the pulverizer divided by the number of outlet pipe flow paths.
    Type: Grant
    Filed: February 7, 1986
    Date of Patent: December 16, 1986
    Assignee: Combustion Engineering, Inc.
    Inventor: Martin J. Kozlak
  • Patent number: 4599954
    Abstract: A process for disposal of wet sewage sludge by introducing a particulate material having BTU values, feeding the mixture to a grinding or milling apparatus in which the particulate material acts to prevent the sewage sludge caking in the apparatus during the reduction in the grinding or milling thereof, supplying hot gaseous medium to dry the mixture, with a portion of the hot mixture being recirculated to assist in the drying of the mixture as it is fed into the grinding or milling apparatus, and disposing of the resulting ground or milled mixture by burning with the aid of the BTU content of the particulate material.
    Type: Grant
    Filed: February 22, 1985
    Date of Patent: July 15, 1986
    Assignee: Williams Patent Crusher and Pulverizer Company
    Inventor: Robert M. Williams
  • Patent number: 4592293
    Abstract: A method of controlling an air heater of a coal-fired boiler system comprising an air heater for heating a primary air used to dry a pulverized coal and convey it into the boiler and a secondary air to combust the pulverized coal by a heat exchange utilizing the exhaust gas discharged from the boiler as a heat source. The air heater includes a primary air heater and a secondary air heater arranged in parallel and the exhaust gas is introduced therein from the boiler by an induced draft fan with the flow rate of the exhaust gas being introduced into each of the air heaters being controlled by a respective gas damper. The heater primary air is mixed with a cold air to have a suitable temperature to dry and convey the pulverized coal, wherein the opening of the damper for the cold air is maintained at a low value of approximate 0% for maintaining the flow rate of the cold air low, while the suitable temperature is obtained by controlling the gas damper for the primary air heater.
    Type: Grant
    Filed: November 9, 1984
    Date of Patent: June 3, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Eiji Toyama, Akira Sugano
  • Patent number: 4589357
    Abstract: The present invention relates to the preparation and burning of biomass-derived fuels such as wood waste or peat. Wood waste or "hog fuel" from the forest industries is of particular interest. Normally the entire stream of this material must be finely ground if it is to be successfully burned in an air suspension burner without any fossil fuel support. It has now been discovered that a bimodally sized fuel can be used. Only about 10-20% of the total heat energy is provided from a portion ground to a size less than about 100 .mu.m. This serves as an ignition component for a principal fuel which may be of much larger size. The usual hog fuel pile contains both bark and wood. Of these two materials, bark is much more friable and easily ground to fine particle size than wood. A major reduction in grinding energy is achieved by selecting the more friable material to be ground to fine size as the ignition fuel. The more resistant material is used as the principal fuel.
    Type: Grant
    Filed: August 22, 1985
    Date of Patent: May 20, 1986
    Assignee: Weyerhaeuser Company
    Inventors: James F. L. Lincoln, Manfred K. Buder, Craig A. Brown, Gregory P. Golike, Robert M. Spurrell
  • Patent number: 4589356
    Abstract: The present invention relates to the recovery of heat values from biomass materials such as wood waste or peat. Wood waste or "hog fuel" from the forest industries is of particular interest. It has been discovered that this material can be burned with no fossil fuel support in an air suspension-type burner without the need to finely pulverize the full fuel stream. One portion of the biomass fuel stream is ground so that it is less than 100 .mu.m in diameter. This fine portion serves as an ignition component and should comprise about 20% of the total heating value of the fuel, using a conventional air suspension burner, or 10% of the total heating value using a staged burner, when the burners are operated at full load. The balance of the fuel can be of much larger particle size. This can be up to about 10 mm or even greater in maximum dimension if used with a grate equipped boiler.
    Type: Grant
    Filed: August 22, 1985
    Date of Patent: May 20, 1986
    Assignee: Weyerhaeuser Company
    Inventors: Terry N. Adams, Robert M. Spurrell, Grant G. Karsner, Gregory P. Golike, James F. L. Lincoln
  • Patent number: 4572086
    Abstract: A system and method of delivering dried fine fuel. Moist coal is extracted from a source and initially dried to a moisture content of five percent by a gas fired dryer plant. The initially dried fuel is then transported to a central processing site whereat the coal is pulverized and further dried and fed to a storage silo. Tractor-trailers receive the dried fine coal from the storage silo and transport same to the end user's site. The trailer is disconnected from the tractor and is utilized as a storage tank as the coal is withdrawn therefrom on an as-needed basis. A fuel injector coupled to a variable rate feeder is utilized in one embodiment to convey the dried fine fuel from the trailer to the burner.
    Type: Grant
    Filed: October 27, 1983
    Date of Patent: February 25, 1986
    Assignee: Convenient Energy, Inc.
    Inventors: Max A. Ladt, Carroll H. Ladt
  • Patent number: 4570549
    Abstract: An improved splitter for use with a coal-fired furnace utilizing a low load burner in which a splitter is provided in the main conduit leading from the pulverizer for splitting the stream of coal and air into two separate streams which are then fed to separate nozzles communicating with the furnace. The splitter includes a damper assembly defining a gap which can be adjustable and including a plurality of projections which prevent coal slippage along the damper blade.
    Type: Grant
    Filed: May 17, 1984
    Date of Patent: February 18, 1986
    Inventor: Norman K. Trozzi
  • Patent number: 4552077
    Abstract: An integrated method of removing alkali metal compounds from sulfur-bearing coal is disclosed. The coal is comminuted (4) and mixed (10) with water (8) to form a slurry (12). In the preferred embodiment, the slurry (12) is comingled with an SO.sub.2 -bearing gas (16) in a transport pipeline (52) to form an acidic slurry which dissolves the alkali compounds out of the coal. The slurry is then separated (22) into a solid portion (24) and a liquid portion (26), the solid portion (24) being combusted (34) to form the SO.sub.2 -bearing gas (16).
    Type: Grant
    Filed: June 27, 1984
    Date of Patent: November 12, 1985
    Assignee: Combustion Engineering, Inc.
    Inventors: Donald C. Borio, Richard W. Borio, Gilbert L. Hale, Arun K. Mehta, Arnold L. Tyler
  • Patent number: 4552076
    Abstract: A method for the cold start of a pulverized coal-fired furnace (10) without prior warm-up of the furnace wherein a supply of microfine pulverized coal (64) supplied from a micropulverizer (60) is combusted to generate a hot gas which is passed to a load-carrying mill (20) as the drying media for the coal pulverized therein. Pulverized coal entrained in the hot gas passes from the load-carrying mill to the load-carrying burner (18) of the furnace (10) and is ignited therein to produce a warm-up flame. A portion of the microfine pulverized coal (68) may also be admixed with the pulverized coal from the load carrying mill (20) to enhance the reactivity thereof. An additional portion (66) of the microfine pulverized coal may be used to fire a pilot igniter to ignite the pulverized coal supplied to the load-carrying burners (18) from the load-carrying mill (20).
    Type: Grant
    Filed: November 19, 1984
    Date of Patent: November 12, 1985
    Assignee: Combustion Engineering, Inc.
    Inventor: Michael S. McCartney
  • Patent number: 4518123
    Abstract: In a method of controlling the pulverization and dryness of a flammable material such as coal, the system is provided with both a push blower upstream from the pulverizer and a pull blower downstream from the pulverizer. The system is controlled so as to maintain the pressure within the pulverizer at an average equal to substantially the atmospheric pressure. In the method for controlling the pulverizing rate, a preset desired differential pressure across the pulverizer is maintained constant while the pulverizing motor speed and the pulverizing material feed rate are modified.
    Type: Grant
    Filed: July 23, 1984
    Date of Patent: May 21, 1985
    Assignee: Kobe Steel, Limited
    Inventors: Kazuo Tanaka, Kenjiro Motonaga, Kozo Tanaka
  • Patent number: 4501204
    Abstract: A tangentially-fired, pulverized coal burning furnace (10) having overfire air (OFA) introduced into the upper portion of the furnace. The fuel and air are introduced (36, 38) into the furnace at the burner level tangentially of an imaginary circle, so that the resultant fireball moves upwardly within the furnace with a rotational spin. The OFA is introduced (40, 42) tangentially of an imaginary circle, in the reverse rotational direction to that of the fireball, so that the exhaust gases flowing from the furnace to the rear gas pass (16) flows in a straight line, with little or no spin. The OFA is made up of a mixture of low pressure air and high pressure air of sufficient volume and pressure to nullify the spin of the fireball.
    Type: Grant
    Filed: May 21, 1984
    Date of Patent: February 26, 1985
    Assignee: Combustion Engineering, Inc.
    Inventors: Michael S. McCartney, William H. Pollock
  • Patent number: 4492171
    Abstract: A solid fuel burner apparatus is provided for burning low density, low mass fibrous fuels such as paper waste and biomass. The burner includes a combustion chamber having a solid fuel and primary air nozzle attached to one end thereof for directing pulverized solid fuel and air into the combustion chamber. The solid fuel and primary air nozzle has a spinning mechanism for spinning the solid fuel and air into the combustion chamber in one direction of rotation. A secondary air input is provided for feeding secondary air into the combustion chamber and includes means to spin the secondary air from the secondary air input into the combustion chamber in a direction opposite in rotation to the direction of rotation of the solid fuel and primary air. A gas fuel input has a flame disk and is positioned to feed gas into the combustion chamber in the center portion of the solid fuel and primary air nozzle to create additional stability in the combustion of the solid fuel in the combustion chamber.
    Type: Grant
    Filed: December 12, 1983
    Date of Patent: January 8, 1985
    Inventors: David F. Brashears, Joseph T. Mollick
  • Patent number: 4489664
    Abstract: A closed loop fuel feeding system for multiple direct fired burners in which a conduit system associated with a fuel grinding mill forms a closed loop for conducting the flow of fuel and air back to the mill in excess of the fuel and air not released from the conduit system to burners, ambient air inlet for admitting sufficient air to replace the air released with the fuel from the system, a back pressure configuration to assure uniform fuel to air density when released from the conduit system, and controls to regulate the rate of fuel supply with the rate of grinding and the quantity of air admitted to complete a combustible mixture of fuel and air.
    Type: Grant
    Filed: November 14, 1983
    Date of Patent: December 25, 1984
    Assignee: Williams Patent Crusher and Pulverizer Company
    Inventor: Robert M. Williams
  • Patent number: 4480560
    Abstract: A method for pneumatically conveying solvent refined coal to a burner under conditions of dilute phase pneumatic flow so as to prevent saltation of the solvent refined coal in the transport line by maintaining the transport fluid velocity above approximately 95 ft/sec.
    Type: Grant
    Filed: December 9, 1983
    Date of Patent: November 6, 1984
    Assignee: International Coal Refining Company
    Inventor: Dennis R. Lennon
  • Patent number: 4475472
    Abstract: Known vortex bed furnaces have a relatively high structural volume in relation to the firing performance. In addition, special devices are necessary for supplying the vortex bed with fuel and with sulphur-absorbing additives. Without subdividing the bed, a partial load can only be achieved with a vortex bed furnace which differs from the full load by only a small percentage. In order to solve these problems, it is proposed according to the invention that the fuel for the vortex bed should be blown with air via at least one dust burner, unsifted, into the combustion chamber, whereby the fine portion of the fuel conducted in is burnt in the dust flame and the coarse portion drops from the dust flame into the vortex bed. The dust burner serves on the one hand to load the vortex bed and on the other hand to increase the relative firing performance, and can be used to improve the suitability for partial load.
    Type: Grant
    Filed: July 26, 1982
    Date of Patent: October 9, 1984
    Assignee: Steag Aktiengesellschaft
    Inventors: Fritz Adrian, Boris Dankow
  • Patent number: 4442783
    Abstract: In a pulverized fuel-fired furnace (10), the temperature of the mixture of pulverized fuel and primary air leaving the mill (36) is measured and compared to a preselected minimum acceptable temperature. Whenever the measured mixture temperature drops below a preselected minimum, the flow damper (78) disposed in the tempering air duct (44) is closed to minimize the flow of tempering air therethrough and a heating fluid (62) is passed in heat exchange relationship with any ambient temperature air leaking past the flow damper in the tempering air duct thereby preheating the tempering airflow. Preferably, hot water (62) is circulated from the waterwall inlet header (22) of the water-cooled water walls (12) of the furnace (10) through a heat exchanger (60) disposed in the tempering air duct (44) and then returned back to the water-cooling circuit (24) of the water-cooled furnace walls at a location upstream of the circulating pump (26).
    Type: Grant
    Filed: August 20, 1982
    Date of Patent: April 17, 1984
    Assignee: Combustion Engineering, Inc.
    Inventors: Thomas L. Pajonas, Gerald F. Barcikowski, Andrew J. Ennaco
  • Patent number: 4436038
    Abstract: A method of igniting a pulverized-coal annular burner flame having an internal back flow region, with the ignition energy being introduced centrally into the interior of the back flow region of the pulverized-coal annular burner flame. The ignition energy for the annular burner flame is furnished by an ignited pulverous fuel igniting flame or pilot light, which is operated with pulverous fuel having a different coarseness and/or consistency than does the primary fuel. The pulverous fuel, which is to be prepared for supplying a pulverous fuel pilot light, is withdrawn from the conduit of the primary fuel after an existing pulverizing plant. The pulverized fuel is withdrawn by means of a withdrawal device which is capable of being shut off, with the removal opening thereof being directed counter to the direction of the primary fuel flow.
    Type: Grant
    Filed: February 12, 1982
    Date of Patent: March 13, 1984
    Assignee: L. & C. Steinmuller GmbH
    Inventors: Klaus Leikert, Klaus-Dieter Rennert
  • Patent number: 4429646
    Abstract: The oil-shale is burned in a combustion chamber (24) having a chimney, and the method comprises:providing a drying gas by mixing hot gas taken from the combustion chamber via a duct (4) with relatively cool gas taken from the chimney via a duct (5), the proportions of said gasses being adjusted as a function quantity of water in said damp shale;crushing lumps of said shale in a crusher (6) and in the presence said drying gas;injecting the resulting grains of crushed shale together with the hot gas into an expansion chamber (8) in which the major portion of the grains falls out from the drying gas, while the lightest portion of grains is entrained by the gas;passing the drying gas together with said lightest portion of grains entrained thereby via a duct (9) through filter means (10) to separate said lightest portion of grains from the drying gas;riddling said major portion of the grains (at 17A, 17B) to provide a larger grain fraction and a smaller grain fraction;recycling said larger grain fraction via a duc
    Type: Grant
    Filed: June 17, 1982
    Date of Patent: February 7, 1984
    Assignee: Societe anonyme dite: Stein Industrie
    Inventor: Guy Quesnel
  • Patent number: 4426938
    Abstract: A method of igniting a pulverized-coal annular burner flame having an internal back flow region, with the ignition energy being introduced centrally into the interior of the back flow region of the pulverized-coal annular burner flame. The ignition energy for the annular burner flame is furnished by an ignited pulverized-fuel igniting flame or pilot light, which is operated with pulverized fuel having a different coarseness and/or consistency than does the primary fuel. Pulverous ignition fuel is withdrawn from the conduit of the primary fuel stream after an existing pulverizing plant at a location which is advantageous with regard to flow dynamics. The ignition fuel is withdrawn by means of a withdrawal device which is capable of being shut off, with the withdrawal opening thereof being directed in the direction of the primary fuel flow.
    Type: Grant
    Filed: February 12, 1982
    Date of Patent: January 24, 1984
    Assignee: L. & C. Steinmuller GmbH
    Inventors: Klaus Leikert, Klaus-Dieter Rennert
  • Patent number: 4419941
    Abstract: A direct-fired, pulverized coal-fired furnace 2, wherein the fuel supply system is modified so that a load carrying pulverizer 10 supplying pulverized coal to the furnace through a plurality of burners 4 may simultaneously also supply pulverized coal to a storage bin 16 for storage therein until needed to start-up, warm-up and stabilize the low load firing of the furnace 2 at a later time.
    Type: Grant
    Filed: October 13, 1982
    Date of Patent: December 13, 1983
    Assignee: Combustion Engineering, Inc.
    Inventor: Richard W. Santalla
  • Patent number: 4397248
    Abstract: A system receives raw coal which is routed through crushing, screening, pulverizing, classifying, and beneficiation stages with the de-mineralized fraction of the coal routed to a pulverized-coal-fired furnace, while the mineralized fraction is routed to a fluidized bed furnace.
    Type: Grant
    Filed: May 26, 1981
    Date of Patent: August 9, 1983
    Assignee: Combustion Engineering, Inc.
    Inventors: Arun K. Mehta, Richard W. Borio