Abstract: A combustion system and method for a coal-fired furnace 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. One stream from the splitter is connected to a separator in which a quantity of air is separated from the mixture of air and coal. A low load burner assembly is provided which includes a first nozzle connected to the separator for discharging the bulk of the coal flow and some air into the furnace, and a second nozzle connected to the same separator for discharging the bulk of the air from the separator into the furnace. The other stream from the splitter is connected to a third nozzle which discharges its mixture of air and coal into the furnace to provide high load capability.

Abstract: A method is provided for improving the sulfur capture potential of lime in the fluidized bed combustion of coal and for improving the flow characteristics of the feed coal therefor comprising collecting partially sulfated limestone particles from the fly ash of the flue gas from the fluidized bed combustor, and (a) retaining said particles in the flue gas stream, thereby hydrating said particles, and returning said particles to the combustor; or (b) mixing said partially sulfated limestone particles with wet coal thereby drying said coal and simultaneously hydrating unreacted calcium oxide to form calcium hydroxide, and recycling said mixture of dry crushed coal and calcium hydroxide into said fluidized bed combustor; or (c) introducing wet coal in the flue gas upstream from said collected particles, thereby providing moisture to hydrate said particles, and returning said hydrated particles to the combustor.

Abstract: A burner combines air cooling and pulverized coal combustion with air for the combustion of low inflammability coals. A ceramic lining protects the cooled steel mantel of the burner while supplying heat for sustained combustion process. Air preheated in the cooling process is used to preheat the coal and to supply secondary air imparting a helical trajectory to the coal particles close to the ceramic lining. The ceramic lining is formed in situ around the flame chamber from molded plastic ceramic hardened by burner operation.

Abstract: A fuel, such as coal, is prepared by mixing with a petroleum product and possibly other materials to form a grease-like substance. In a motionless mixer the grease-like substance is combined with air to form a foam-like dispersion of fuel and air. Such foam-like dispersion is delivered substantially continuously to a combustion chamber for combustion thereat. The combustion chamber is relatively closed and has means cooperative with the foam-like dispersion and the pressure of expanding gases of the combustion process to impede flow of the foam-like dispersion therein; consequently the foam-like dispersion is maintained at a pressure head to maintain the air dispersion therein. The speed and heat of combustion may be controlled by controlling flow rate or pressure of the foam-like dispersion. Means are provided for reducing pollutants and for efficiently transferring heat out from the combustion chamber.

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.

Abstract: Coal energy is delivered from the mine to a distant point of use by a system involving the pulverization of the coal at the mine, and carrying it as a nonexplosive suspension in a pipeline or conduit, with high pressure coal gas which is made at the mine being employed as the transport medium. At the delivery point, the gas, as well as the coal dust can be fired directly into the furnace, or the coal can be separated from the coal gas and stored. Arrangements are provided for insuring that the finely pulverized coal may be maintained in suspension within the transport pipe, and such arrangements may include spiraling vanes to insure that settling particles are reintroduced into the main gas stream, and separate sections within the pipe, or a supplemental pipe for the high pressured gas to permit restarting of the flow in the event of a power failure and the settling out of the particles.

Abstract: Combustor and process for burning particularized oil shale by preburning separate fine and coarse particle feedstreams prior to mixing in the main combustion zone.

Abstract: The furnace has a feeding channel (4) through which firewood is transported into a fire chamber (3). A steam pipe (10) leads into the channel (4). Through said pipe (10), steam is introduced into the solid fuel material in bursts as soon as a certain temperature is exceeded within the said channel (4). The steam increases the humidity in the air and the moisture of the firewood, thereby reliably preventing a spreading of the fire within the feeding channel (4), without simultaneously impairing combustion within the fire chamber (3).

Abstract: An improved pulverized fuel burning method and apparatus having means for decreasing the pressure drop through the burner nozzle and decreasing the formation of nitric oxides, including a splash plate to breakup a natural forming fuel-rope, a deflector to deflect the fuel-rope, and a diffuser to disperse the pulverized fuel into a more desirable fuel burning distribution pattern.

Abstract: A fluidized bed combustion chamber (3) is provided with a perforated bottom plate (4) into which air nozzles (18, 19) are pressed in a manner similar to that used for tubes in a tube sheet of a heat exchanger. About one-third of the nozzles (18) are connected to a startup or auxiliary combustion chamber (14) for blowing in hot gas for heating the bed to the flash-point or ignition temperature of the fuel. Further, the bottom plate is insulated (20) between the nozzles. (FIGS. 1, 4.) A method of operating such a combustion chamber also is disclosed.

Abstract: A burner for pulverized coal such as in a rotary kiln includes three concentric cylindrical ducts. The outer duct carries an air supply which is directed in a generally axial direction into the kiln. The next innermost duct carries the pulverized coal-carrier gas mixture and is also generally directed in an axial direction. The next innermost duct carries air which is directed in a divergent radial direction in the kiln and includes a rotational air component. By controlling the quantities of air in the ducts which flank the coal duct, the resulting flame form can be controlled in the kiln without restoring to variations in the velocity or direction of the coal carrier gas stream. By eliminating such variations in regard to the coal carrier gas stream, the abrasive action of the pulverized coal is kept to a minimum.

Abstract: The present invention is directed to the extraction of energy values from l shale containing considerable concentrations of calcium carbonate in an efficient manner. The volatiles are separated from the oil shale in a retorting zone of a fluidized bed where the temperature and the concentration of oxygen are maintained at sufficiently low levels so that the volatiles are extracted from the oil shale with minimal combustion of the volatiles and with minimal calcination of the calcium carbonate. These gaseous volatiles and the calcium carbonate flow from the retorting zone into a freeboard combustion zone where the volatiles are burned in the presence of excess air. In this zone the calcination of the calcium carbonate occurs but at the expense of less BTU's than would be required by the calcination reaction in the event both the retorting and combustion steps took place simultaneously. The heat values in the products of combustion are satisfactorily recovered in a suitable heat exchange system.

Abstract: A bed support, and a fluidized bed reactor incorporating the bed support, the bed support including a conical-shaped support with downwardly converging surfaces terminating in a conduit for removing tramp material and/or agglomerated material from the reactor. The downwardly converging surfaces have main air source nozzles for directing pressurized air parallel to and downwardly along the downwardly converging surfaces toward the conduit. In a first embodiment, the conduit has downwardly diverging walls. In a second embodiment, the conical-shaped support further includes an inverted cone positioned over the conduit, the inverted cone having central air source nozzles and slots in the lower portion of the cone. In a third embodiment, the conical-shaped support further includes a bar grate having central air source nozzles positioned within the conduit.

Abstract: A fuel stream comprising a combustible pulverized material entrained in a carrier gas is formed and subsequently injected into a blast furnace with the hot blast air without any detrimental effect on the hot air blast and with minimum energy consumption. The volume flow rate and pressure of the carrier gas are controlled as functions of the furnace pressure and the pulverized material feed rate is simultaneously controlled as a function of the carrier gas pressure drop.

Abstract: A supply container contains therein a supply of granular or pulverulent solid fuel material. A air supply conduit extends into the supply container and has an outlet end at a position within the supply container to be embedded within the solid fuel material. The fuel outlet conduit extends into the supply container and has an inlet end at a position within the supply container to be embedded within the solid fuel material. The outlet end of the air supply conduit and the inlet end of the fuel outlet conduit confront each other and are separated from each other by a space. A feed flow of air is supplied through the air supply conduit outwardly through the outlet end thereof, to entrain and blow particles of the solid fuel material positioned in the space into the fuel outlet conduit. The feed flow of air and particles entrained thereby are then discharged into a transport conduit and conveyed to a burner.

Abstract: A method for operating a coal dust furnace comprises blowing into the furnace a mixture of combustion air and combustion coal dust having a specified range of grain sizes, the range of grain sizes having an upper limiting grain size, and, for reducing the temperature of the flame, also blowing into the furnace additional temperature reducing coal dust, the range of grain sizes of the additional coal dust lying essentially above the specified upper limiting grain size, this temperature reducing coal dust subsequently being burnt in additional areas of the furnace. The two types of coal dust are blown into the furnace in concentric streams each surrounded by an annular stream of its associated combustion air. If the combustion coal dust is the central stream, then its combustion air is fed in a swirling stream.

Abstract: A safety device for protecting a burner of a coal gasification plant against solid blockage. Solid blockage may occur in a burner of a coal gasification plant fed with a mixture of coal particles and fluid. In order to protect the burner against solid blockage a safety device is proposed which is arranged in the supply line to the burner. By means of this safety device relatively large pieces of solid material, which might cause blockage of the burner, can be eliminated from the mixture of coal particles and fluid supplied to the burner.

Abstract: A fluidized bed heat exchanger in which a bed of particulate material is supported on a grate in a housing and air is passed through the grate and the particulate material to fluidize the bed and promote the combustion of combustible material contained therein. A baffle system is disposed in the housing for impacting with the entrained particulate material in the air and gaseous products of combustion to remove the latter material and permit it to fall by gravity back to the bed. A series of tube sections are provided in the housing for directing the air and gaseous products to the baffle means and gases are injected from the proximity of the baffle means downwardly towards the bed.

Abstract: A fluidized-bed system for feeding coal or a coal-limestone mixture into a fluidized bed combustor, a perforated horizontal distributor plate dividing the chamber into upper and lower chamber sections, means for feeding solid fuel particles into the upper chamber section, a source of high velocity gas connected to the lower chamber section and passing through the plate into the upper chamber section for entraining the particles, means for heating the high velocity gas before it is introduced into the upper chamber, an entrainment section defined by converging upper sides of said fuel feeding chamber, and a stream splitting section disposed above said entrainment section and connected to a plurality of pneumatic transport lines each penetrating the distributor plate of a fluidized bed combustor and terminating in an outlet feedport.

Abstract: A combustion apparatus which has a burner having an inner wall lined with a refractory material forming a combustion chamber and an outer wall spaced from the inner wall by spacing members. A primary air supply supplies air to the burner combustion chamber through the outer and inner walls. A pulverizer for pulverizing solid fuel is connected to the primary air supply for feeding the pulverized solid fuel to the burner combustion chamber. A secondary air supply supplies air to the burner between the inner and outer walls and into the burner combustion chamber. The secondary air supply supplies air to an area of negative pressure in the combustion chamber created by the swirling flow of air from the primary and secondary air supply. An ignition pilot is mounted through the burner inner and outer walls adjacent to the primary air and fuel feed. The ignition pilot has a pilot flame detector which looks at the pilot and the main combustion flame.

Abstract: A solid fuel particle and air control device for use with combustion systems for a gas turbine engine and the like is disclosed. The device has a first housing with an inlet passage for receiving solid fuel particles. The first housing is mounted on a second housing with a blind cavity. A first passage extends through the second housing so as to intersect the blind cavity to permit flow communication therebetween. Solid fuel particles from the inlet passage of the first housing are metered and transfered to the blind cavity. A fluid pressure source is injected into the first passage in the secondary housing so as to entrain the solid fuel particles in the air as to form a uniform air entrained mixture. The air entrained mixture is then ejected out of the first passage in the second housing to a duct which communicates with the combustion system of the gas turbine engine where the air entrained solid fuel particle mixture is burned.

Abstract: A fluid bed heater or vaporizer unit has a generally cylindrical configuration with its major axis horizontally disposed. A mixture of coal and limestone is fed into the elongated fluidized bed within the unit for combustion; the limestone being present to minimize sulfur emissions due to the sulfur present in the coal. The wall of the unit in the region of the freeboard is lined with horizontally disposed heat exchange tubing. The delivery of air to the fluidized bed is regulated so as to establish a combustion zone of high turbulence and one or more heat transfer zones of lower turbulence. A plurality of heat exchange tubes are located in the heat transfer zone or zones and within the expanded bed level of the fluidized bed but above the region occupied by the slumped bed. Economizer heat exchange coils may be located in the passageway for exhaust gases.

Abstract: A fluidized bed for the combustion of coal, with limestone, is replenished with crushed coal from a system discharging the coal laterally from a station below the surface level of the bed. A compartment, or feed box, is mounted at one side of the bed and its interior separated from the bed by a weir plate beneath which the coal flows laterally into the bed while bed material is received into the compartment above the plate to maintain a predetermined minimum level of material in the compartment.

Abstract: In a fluidized bed reactor having a reactor vessel, two detector vessels are mounted in the reactor vessel near the inside surface of the reactor vessel in the fluidized bed and in the gas outlet region. Each detector vessel contains larger detecting particles and passes the gas in the reactor vessel. Pressure drop across the detecting particles is measured. The ratio of the two pressure drops represents the ratio of the fluid velocity and minimum fluidizing velocity under the operating conditions and can be used as control factor.

Abstract: A system for supporting a fluidized bed in a boiler in which a plurality of support frames are supported in an abutting relationship spanning the interior of the boiler. One or more of the support frames are connected or attached relative to each other and to their supports in a manner to permit limited relative movement between the frames and between each frame and its support. A grid is supported by each frame and is connected or attached thereto in a maner to permit limited movement of the grid relative to the frame.

Abstract: A method of burning fuel with lowered emission of nitrogen oxides comprises feeding pulverized fuel to the main burner in a combustion furnace and additionally feeding pulverized fuel to the region of the furnace where the first fuel is about to conclude its combustion, using inert gas with or without a low oxygen content as a conveying fluid, while supplying oxygen or air to a region downstream of the region for fuel addition.

Abstract: A pulverized solid fuel is injected into a shaft furnace by being entrained in a stream of pressurized air, the resulting fuel-air mixture subsequently being further mixed with heated air being delivered to the furnace via a tuyere. The air used to entrain the pulverized fuel is diverted from the cold air supply to a mixing station, which is used to control the temperature of the hot air supplied to the furnace via the tuyere, and this diverted air is pressurized prior to the pulverized material entrainment.

Abstract: A first atmospheric bubbling fluidized bed furnace is combined with a second turbulent, circulating fluidized bed furnace to produce heat efficiently from crushed solid fuel. The bed of the second furnace receives the smaller sizes of crushed solid fuel, unreacted limestone from the first bed, and elutriated solids extracted from the flu gases of the first bed. The two-stage combustion of crushed solid fuel provides a system with an efficiency greater than available with use of a single furnace of a fluidized bed.

Abstract: A coal burner and rotary metal melting furnace incorporating the same is provided in the form of a generally cylindrical furnace rotatable about a horizontal axis and fired through one end with pulverized coal and preheated air through a burner structure which impinges the preheated air in a helical path against a conical spray of finely divided coal.

Abstract: A heater for burning particulate fuels in which a stream of air carrying combustible particles is injected upward into a combustion chamber (22) between two spaced perforated tubular members (33, 34), the outer member being taller. A deflector (55) located within the outer member and above the inner member causes the stream to flow outward and then upwardly, and helical vanes (139) may be provided between the members. A gun-type oil burner (61) is located below the members for initially heating them and igniting the particles. Particulate fuel is supplied through an auger 70 from a bin 71 which contains springs 77 rotated to prevent bridging or caking of the material. Rotation of the springs and drive of the auger are powered by a common motor 80.

Abstract: Fine particulate solid fuel particles are delivered from a venturi ejector to a rotating double-armed distributor which distributes fuel and air sequentially to conduits leading to the burner ejector of a kiln. The distributor is sealed and pressurized with air so as to provide the conduits with additional pulses of air following the times at which they receive fuel and air from the distributing operation.

Abstract: An entrained bed combustor may provide constant temperature, superheated steam to a power generating steam turbine independent of the load on the turbine. In a conventional utility boiler heat is transferred in series to the steam generator, superheater and reheater. With the present invention these components may be run in parallel with heat transfer from the entrained bed particles enabling faster start-up and a turn-down capability without a reduction in the superheated steam temperature.

Abstract: A system and method for increasing the sulfation capacity of alkaline earth carbonates to scrub sulfur dioxide produced during the fluidized bed combustion of coal in which partially sulfated alkaline earth carbonates are hydrated in a fluidized bed to crack the sulfate coating and convert the alkaline earth oxide to the hydroxide. Subsequent dehydration of the sulfate-hydroxide to a sulfate-oxide particle produces particles having larger pore size, increased porosity, decreased grain size and additional sulfation capacity. A continuous process is disclosed.

Abstract: The vertical fuel pipe of a fluidized bed extends up through the perforated support structure of the bed to discharge granulated solid fuel into the expanded bed. A cap, as a deflecting structure, is supported above the discharge of the fuel pipe and is shaped and arranged to divert the carrier fluid and granulated fuel into the combusting bed. The diverter structure is spaced above the end of the fuel pipe and provided with a configuration on its underside to form a venturi section which generates a low pressure in the stream into which the granules of solid fuel are drawn to lengthen their residence time in the combustion zone of the bed adjacent the fuel pipe.

Abstract: In a pulverized coal-fired steam generator having a generally vertical furnace (1) and a plurality of fuel-air admission assemblies (10) arrayed in a vertical windbox (40) in one or more walls of the furnace (1), at least one of the fuel-air admission assemblies (10) being a low load fuel-air admission assembly having a split coal bucket (30) with vertically adjustable upper and lower coal nozzles (32,34), the remaining assemblies having vertically adjustable single nozzle buckets (28), a tilt apparatus (50,60) for vertically adjusting all nozzles in unison in response to steam temperature at high loads and for vertically adjusting the lower coal nozzles of the split coal bucket of the low load fuel-air admission assembly independent of all remaining nozzles at low loads.

Abstract: An arrangement that utilizes agglomerating coal as a binder to bond coal fines and recycled char into an agglomerate mass that will have suitable retention time when introduced into a fluidized bed 14 for combustion. The simultaneous use of coal for a primary fuel and as a binder effects significant savings in the elimination of non-essential materials and processing steps.

Abstract: Apparatus for supporting a perforated plate (24) air distributor for a fluidized bed combustion boiler. The plate (24) is supported (26) around its entire periphery, and at given points (42) within its periphery, in such a manner that it is free to expand due to thermal growth in a horizontal direction, while still being capable of supporting a vertical load (12) without sagging, buckling, or being subject to failure.

Abstract: A fluidized bed combustor comprises a housing having a chamber therein with a top having a discharge for the gases which are generated in the chamber and a bottom with a discharge for heated fluid. An assembly is arranged in the lower portion of the chamber and the assembly includes a lower plate which is mounted on a support flange of the housing so that it is spaced from the bottom of the chamber and defines a fluid plenum between it and the bottom of the chamber for the discharge of heated fluid. The assembly includes a heat exchanger inlet plenum having tubes therethrough for the passage of fluidizer air and a windbox above the heat exchanger plenum which has a distributor plate top wall. A portion of the chamber above the top wall defines a fluidized bed.

Abstract: A pressurized, fluidized bed combustor including a housing having a combustor chamber therein with a distributor plate closing the lower portion of the housing and arranged above a fluidizer windbox, which, in turn, is arranged above a heat exchanger inlet plenum which is mounted above a bottom of the combustor. A coal gun is provided for discharging coal into the fluidized bed, and it comprises an outer guide tube which extends from a spaced location above the distributor plate downwardly through the bottom of the combustor chamber and it includes a portion which extends exteriorly of the combustor chamber. This exterior portion carries a ball valve which has a passage therethrough which makes it possible to insert a coal supply pipe upwardly in the interior of the outer guide pipe and through the passage of the ball valve up to substantially the top of the outer pipe at a location above the distributor plate within the reaction bed.

Abstract: This invention relates to an improved method and apparatus for continuous autogenic incineration of high-moisture easily friable combustible agglomerates in a fluidized bed. The improvement comprises introducing the waste materials into the bed in a "tube" of air provided by supplemental air means which surrounds the in-bed feed means.

Abstract: The invention provides a fluidized bed combuster for fuel or waste material, preferably having a fluidized bed which is arranged to circulate about a horizontal axis, in which one or more baffles are provided to define respective quiet zones adjacent the fluidized bed; material flowing in operation of the bed over the top of the baffle from the fluidized bed to the quiet zone and under the baffle from the quiet zone to the fluidized bed; and means is provided for feeding material to be burnt into the quiet zones to be carried therefrom beneath the baffles into the fluidized bed for combustion therein.

Abstract: Coal is ground or pulverized to an extremely small particle size (6 microns or less) and introduced into a mixing chamber where the coal powder is atomized or mixed with air to form a cloud of coal particles entrained in air. Prescribed, controlled amounts of the coal powder/air mixture are withdrawn from the mixing chamber and fed to the burner nozzle of a furnace, from which nozzle the mixture is directed to a combustion zone. The igniter for the system is positioned at the combustion zone and is preferably a strong electric arc, although other igniters could be used. After combustion exhaust gases from the furnace are withdrawn and cleaned up through a water filter in which a plurality of screens are kept flushed with water passing in one direction as the combustion gases pass in the opposite direction to the atmosphere.

Abstract: A fluidized combustor is provided with a burning zone having cooling passages in its upper portion and a lower portion beneath said passages yet deep enough so that material therein may be operated in a fluid bed combustor mode with cooling by fluidizing excess air, a separate zone being provided for selective storage therein of materials transferred from the burning zone.

Abstract: An improved fuel-air admission assembly having a plate disposed along the longitudinal axis of the coal delivery pipe. The leading edge of the plate is orientated across the inlet end of the coal delivery pipe so that the high coal concentration portion of the primary air-pulverized coal stream discharging along the outer radius of the main fuel pipe outlet elbow is separated from the low coal concentration portion of the primary air-pulverized coal stream discharging along the inner radius of the main fuel pipe outlet elbow. The trailing edge of the plate is orientated across the outlet end of the coal delivery pipe so that the high and low coal concentration streams are directed into the furnace through separate nozzles.

Abstract: A boiler wherein the combustion unit includes a fluidized bed which may be fluidized in a non-uniform manner to effect circulation of bed material by means of dual air distributors located within the bed.

Abstract: This invention relates to fluidized bed combustors and provides for the operation of such combustors so that the bed forms an upper fluidized layer and a lower, more static, layer into which larger particles may fall to be drained away.

Abstract: An apparatus and method for maintaining the heat input to a pulverized coal-fired steam generator when firing a lower grade coal than for which the pulverizers were designed. A dense phase pulverized coal stream consisting essentially of a mixture of pulverized coal and air having an air-to-coal weight ratio below approximately 1.0 is injected into main pulverized coal stream, thereby providing the necessary supplemental fuel for maintaining the heat input at that full load level.

Abstract: A fluidized bed boiler feed system for the combustion of pulverized coal. Coal is first screened to separate large from small particles. Large particles of coal are fed directly to the top of the fluidized bed while fine particles are first mixed with recycled char, preheated, and then fed into the interior of the fluidized bed to promote char burnout and to avoid elutriation and carryover.

Abstract: Pyrolyzing pulverized coal to form char and volatiles, separating the char from the volatiles, burning the char in heat-transfer relationship with a stoichiometric excess of air, forming thereby ash and a mixture of gases, the excess of air being chosen to produce in the ash a temperature below the fusion temperature thereof, separating the mixture of gases from the ash, and thereafter burning the volatiles in the mixture of gases.

Abstract: A fuel-staging burner assembly and method in which a burner nozzle has separate, concentrically disposed elements to burn coarse and fine coal particles under different combustion conditions to reduce the production of nitrogen oxides from the combustion of coal as a fuel. The burner assembly further includes a control nozzle for maintaining a swirling motion in the combustion flame and a separate, axially-movable adjustable sleeve for regulating the quantity flow of turbulence-free combustion-supporting air.