Abstract: The carbon content of the residue from combustion of agricultural waste products and the fly ash content of the gaseous exhaust is controlled by regulated inflow of the combustion supporting air in a plurality of flow stream at different velocities to enhance fluidization of particulate feed in a bed being raked by a rotating sweep arm inducing radially outward movement of combustion residue into a collecting zone from which the residue enters a discharge duct. The particulate feed is dropped at location in the combustion chamber above the bed in alignment with the inflow stream of maximum velocity.

Abstract: The invention relates to a method of igniting, upon start-up, a combustion chamber (8) in a power plant with combustion of fuel in a fluidized bed (14). The air flow through the nozzles (13) of the combustion chamber bottom (12) for fluidization of the bed (14) and for combustion of the fuel can be reduced upon start-up; bed material, which is heated to the ignition temperature of a start-up fuel, is transferred from a storage container (40) to the combustion chamber (8), and fuel is supplied to the bed (14). In those cases where the air flow has been reduced during the transfer of the bed material, it is increased again when the fuel is supplied. The invention also relates to a power plant having means for temporarily bypassing the nozzles (13) of the combustion chamber bottom (12) while transferring hot bed material from a storage container (40) to the combustion chamber (8), and a fuel system (30-38) for the supply of fuel to the combustion chamber (8).

Abstract: An improvement in method and apparatus of fluidized beds involving heat or combustion by pre-heating the exterior and interior of the fluidized bed in unison through the use of an exterior chamber surrounding the fluidized bed chamber. This exterior chamber also provides equalization of fluidizing gas temperature with internal fluid bed temperatures during operation of the bed and allows for a scaling down of the fluidized bed to a small size without sacrificing high efficiency.

Abstract: A method for combustion of sulfur-containing fuel in a circulating fluid bed combustion system wherein the fuel is burned in a primary combustion zone under reducing conditions and sulfur captured as alkaline sulfide. The reducing gas formed is oxidized to combustion gas which is then separated from solids containing alkaline sulfide. The separated solids are then oxidized and recycled to the primary combustion zone.

Abstract: A system for removal of tramp or trash material from a single fluidized bed contained within a single vessel used to incinerate or pyrolyze solid fuel, the system comprises a gently sloped, skewed or serpentine stationary bed support and air distributor structure which distributes air in a fashion so as to uniformly fluidize a shallow bed of variable depth across the slope thereof without internally circulating the bed, and at the same time cause non-combustible tramp or trash material (e.g. pieces of steel, rocks, clumps, etc.), to be removed from the bed without passing to a location either above or beneath the bed. The angle of slope is strictly controlled. During periods of non-fluidization and/or non-use, the bed material is kept from falling into the air distribution plenum below the bed support structure by hollow bed containment structure disposed at sites below the bed support structure.

Abstract: A ring-gap nozzle for distributing a fluid medium over a plate, for instance over a bottom plate in a fluidized bed dryer, having two dish-shaped pressed parts suiting to each other complementarily being assembled in facing relationship and nested into each other and forming a ring gap through which the medium, deflected by 90.degree. or more, flows to the bottom plate, preventing both the settling of the product to be treated in the fluidized bed dryer on the plate as well as the reflux of the product backwardly into the nozzle when the flow of medium is cut off. This type of nozzle is simple to manufacture and does close the passage without any complicated manipulation automatically.

Abstract: A system for treating solid, granular and aggregate material thermally including a storage silo containing a supply of the material to be thermally treated. A combination thermal reclaimer and heat exchanger apparatus is connected in fluid flow relation to the storage silo for receiving material therefrom. The combination thermal reclaimer and heat exchanger apparatus is operative to both effect a preheating of material received thereby and to accomplish a thermal reclamation of the material received thereby as the material completes its passage through the combination thermal reclaimer and heat exchanger apparatus. A feeder device is cooperatively associated with the combination thermal reclaimer and heat exchanger means for receiving thermally reclaimed material therefrom. The feeder device has a transporter pipe cooperatively associated therewith into which thermally reclaimed material is fed. The transporter pipe is operative for transporting the thermally reclaimed material to a material storage device.

Abstract: A thermal decomposition furnace in which waste tires having original shape, not broken up, can be laid horizontally and be thermally decomposed. The furnace is constructed by providing a feeder above, forming downward a fluidized bed-forming section having inlets for air, forming beneath a sealing bed-forming section of right cylindrical shape having a diameter smaller than that of fluidized bed-forming section, and installing a conveyor below said sealing bed-forming section. At the lower end of sealing bed-forming section, an oblique opening is formed so as to keep an progressively increasing clearance to the conveyor in the direction of advance of conveyor.

Abstract: A low BTU, low volatile content, low carbon and high ash fuel is combusted in a combined shaft kiln combustor and fluidized bed combustor to generate heat which is converted to useful energy. The fluidized bed combustor is mounted vertically above the shaft kiln combustor. A venturi is provided in a passageway connecting the shaft kiln combustor and the fluidized bed combustor to produce a gaseous stream moving at a velocity sufficient to separate finer particles from the low BTU, low volatile content, low carbon and high ash fuel so that the coarser particles are burned in the shaft kiln combustor and the finer particles are burned in the fluidized bed combustor.

Abstract: The air dispersion plate at a lower part of a fluidized bed combustion furnace is provided with a large number of air injection nozzles uniformly distributed therethroughout and made of a porous refractory material having good air permeability and high heat and wear resistances. All of the fluidizing air supplied into the wind box below the dispersion plate is injected through these nozzles into the combustion chamber to fluidize the fluidizable material, which, after combustion is stopped, cannot flow through the nozzles into the wind box to cause heat damage and contamination therein and in the air supply pipe.

Abstract: A thermal decomposition furnace in which waste tires having original shape, not broken up, can be laid horizontally and be thermally decomposed. The furnace is constructed by providing a feeder above, forming downward a fluidized bed-forming section having inlets for air, forming beneath a sealing bed-forming section of right cylindrical shape having a diameter smaller than that of fluidized bed-forming section, and installing a conveyor below said sealing bed-forming section. At the lower end of sealing bed-forming section, an oblique opening is formed so as to keep a progressively increasing clearance to the conveyor in the direction of advance of conveyor.

Abstract: A nozzle plate construction for underjet coke ovens for distributing and metering combustion-supporting air supplied upwardly to regenerators through a sole flue extending parallel to the chamber axis. The sole flue is closed at the top by plate elements having apertures therein. In accordance with the invention, the various plate elements are in the form of troughs having plane base plates each formed with one longitudinal gap therein. Associated with each longitudinal gap is a metering element so mounted at its ends so as to be adjustable in its distance from the plane of the base plate. In this manner, the air flowing upwardly into the regenerator sections can be accurately controlled and uniformly distributed. At the same time, the nozzle plate construction of the invention is light in weight while being very stable and easy to assemble.

Abstract: Description is of fluidized bed shell boiler arrangements in which the sides of the bed within the furnace tube are generally vertical, being provided by vertical walls within the furnace tube. The bed walls may include water tubes or be substantially vertical portions of arcuate panels mounted within the furnace tube. Fluidizing gas is fed to fluidizing gas ducts communicating with the bed from a plenum chamber including paddles movable into positions closing off at least some of the ducts during initial start up of the boiler to reduce the amount of combustible gas (or hot gases) fed to the ducts when heating the bed to its operating temperature. The ducts may be formed by mounting halfround or U-shaped member on the bottom of the furnace tube, the ducts tapering along their lengths such that the gas passing into the bed exits at substantially the same velocity across the width and length of the bed.

Abstract: A fluidized bed furnace and boiler for the combustion of flyash with a moisture content of 45% by weight. The flyash is produced as a by-product of a coal gasification process and transported in water to a slime dam. From the slime dam a slurry of flyash and water is initially thickened in a gravity thickener (1) (FIG. 1) and then converted to filter cake in a tubular filter press (4). The filter cake is fed through pressurized hoppers (8) and chutes to the base of the boiler (10) and is distributed across the floor through chutes in the side walls and through chutes surrounded by a tubular array of water tubes and extending into the boiler furnace chamber terminating approximately one quarter of the furnace width from the side walls. A fluidized bed with a depth of about 3 meters is formed by discharging air heated in an associated air heater through nozzles in the floor of the furnace chamber to effect combustion.

Abstract: An installation for gasifying coal in a fluidized bed under high pressure has a vessel resistant to the high pressure and a reactor disposed in the interior of the vessel and having a principal chamber constituting a gasification chamber which permits the establishment of a principal fluidized bed of substantial depth and an auxiliary fluidized bed of a smaller depth. An inclined traveling grate forms the bottom of the gasification chamber and has a lower grate portion supporting the principal fluidized bed and an upper grate portion supporting the auxiliary bed situated in a space between the vessel walls and the gasification chamber. The principal and auxiliary fluidized beds are maintained in hydrostatic equilibrium.

Abstract: A system for removal of tramp or trash material from a single fluidized bed contained within a single vessel used to incinerate or pyrolyze solid fuel, the system comprises a gently sloped, skewed or serpentine stationary bed support and air distributor structure which distributes air in a fashion so as to uniformly fluidize a shallow bed of variable depth across the slope thereof without internally circulating the bed, and at the same time cause non-combustible tramp or trash material (e.g. pieces of steel, rocks, clumps, etc.), to be removed from the bed without passing to a location either above or beneath the bed. The angle of slope is strictly controlled. During periods of non-fluidization and/or non-use, the bed material is kept from falling into the air distribution plenum below the bed support structure by hollow bed containment structure disposed at sites below the bed support structure.

Abstract: A steam generator arranged as a single-pass boiler with a stationary fluidized-bed hearth and a superimposed ash-circulating system. The fluidized bed is divided into several individually controllable sections to which, in each instance, there is associated a belt-charging machine, an ash separation and ash return system, and a secondary air feed line.

Abstract: To prevent the tube to a pressure measuring means from being blocked by solid material mobile in a pressure container, a small part of the clean pressure medium from a source of such medium is injected into the tube so that the tube is continuously purged with clean pressure medium. By locating the pressure medium input at a suitable position along the tube relative to the pressure measuring means, the desired purging of the tube is obtained without appreciably increasing the pressure in the tube, and thus minimizing possible errors in measurement of the pressure. If, for example, pressure medium is passed into a pressurized combustion chamber through a surrounding pressurized container, and the tube to the pressure-measuring means passes through said surrounding pressurized container, the clean pressure medium can be bled into the tube through a hole bored in the side of the tube within the pressurized container.

Abstract: Method and a device for controlling the temperature of a reaction carried out within a vessel in a fluidized bed containing solid particles which can be entrained with the smoke and then recovered in a separating device and recycled into the fluidized bed after passage through a heat exchanger where they yield up their heat. The flow of particles separated from the smoke is divided into two parts, a hot part recycled directly into the fluidized bed and a cool part constituted by particles taken up at the outlet of the separating device and passed into the heat exchanger to constitute a reserve of cold material which can be mixed with the hot part before reinjection into the fluidized bed, the relative flow rates of the hot particles and of the cold particles being regulated so as to control the flow-rate and the average temperature of the flow of particles recycled into the fluidized bed for maintaining at the desired level the reaction temperature in the midst of the latter.

Abstract: A furnace for burning sawdust wherein combustion of the fuel is complete and recovery of heat of combustion is high, which incorporates an aspirator for controlling combustion of the fuel and for secondarily recovering heat from the products of combustion, and additionally for cleaning the exhaust gases. The invention incorporates primary and secondary heat exchange chambers.

Abstract: Apparatus for burning material such as fuel, waste material and the like, which when burned produces gases within which pollutants are entrained and for cleaning the gases. The apparatus comprises an incinerator or a furnace having a combustion chamber in which the material is burned and in which tubes, preferably apertured, extend through the burning coke to which solid fuels are reduced and through the flames of an oil burner gun, for example within the confines of the combustion chamber which in such an instance is also a refractory chamber, act to conduct the polluted gases of combustion from the burning material through the same burning material where they are super heated and cleaned.

Abstract: A fast fluidized bed reactor, comprising an upright reaction chamber for containing a bed of granular material, the chamber having a cylindrical upper region and a lower region; a feeder for feeding matter into the lower region; apparatus for supplying pressurized air to the reaction chamber to fluidize the granular material in the circulating regime, whereby a portion of the granular material is entrained into the upper region; apparatus for tangentially supplying pressurized air to the upper region, the second stream of air being supplied, and the reactor being constructed, in a manner to provide a Swirl number of at least 0.

Abstract: A two-stage process for staged combustion of crushed retorted particles, especially sulfur and nitrogen-bearing shale, provides maximum heat from combustible materials in shale while emissions of carbon monoxide and oxides of sulfur and nitrogen are minimized. In the first stage, combustion is maintained under fluidizing conditions with a substoichiometric amount of oxygen. Off-gases from the first stage are burned in a second-stage combustion zone utilizing an oxygen-containing gas stream controlled to limit emission of carbon monoxide in the flue gas. To minimize production of sulfur oxides, combustion temperature is concurrently maintained below a peak value of 1700.degree. F. by introducing inert gas or recycled decarbonized fines to the first-stage combustion zone to reduce temperature therein.

Abstract: A boiler comprising a fluidized bed combustion chamber which communicates with an exchange enclosure containing water tubes heated by the combustion tubes and within which is arranged an exchange and dust removal chamber equipped with water tubes and containing a vertical internal partition dividing it into two half chambers communicating with one another. One of these half chambers communicates with the upstream part of the enclosure through an inlet orifice situated at the top part and constrains the fumes to follow a descending path along the partition, while the other communicates with the downstream part of the enclosure through an outlet orifice situated at the top part and constrains the fumes to follow an ascending path.

Abstract: An apparatus for recovering energy from pyrolyzable, carbonaceous waste materials, for example household refuse, comprising a rotary tube reactor (4) adapted to be charged with the waste materials and producing, as products, a (low temperature) carbonization gas and a pyrolytic coke at a reaction temperature of above 200.degree. C.; a fluidized bed or swirling layer gasifier adapted to be supplied with an oxygen-containing gasifying agent, the pyrolytic coke and, optionally, waste materials and from which exit a hot gas having a temperature of between 400.degree. and 1000.degree. C. and an inert ash. Further, the system includes cleaning stages (8, 20) for the carbonization gas, connected subsequent to the rotary tube reactor and the gasifier (14), and further a combustion device (24) for the cleaned gases, as a part of a boiler system.

Abstract: The invention includes the steps of, and suitable apparatus for, maintaining a plurality of relatively dense bead-like particles of inert solid material dispersed throughout the fluidized combustion bed, for circulation through heat exchange means separated from the combustion bed and return to the fluidized bed along with other bed constituents. Fine limestone particles may also be introduced into the combustion bed along with fresh fuel particles. The circulating bed constituents are discharged from an arched heat exchange outlet to direct the returning bed constituents in a generally horizontal direction directly over the combustion bed for generating increased circulation in the bed. In addition, the inlet for introduction of fresh fuel and fine limestone is located just below the arched discharge channel to enhance horizontal discharge velocity.

Abstract: A completely cooled fast fluidized bed boiler comprises a reactor (4) having a bottom section (3), an integrated primary non-centrifugal mechanical particle separator (5), a gas pass (7) containing convective heat exchangers (10), and means (6,8,9) for controllably recirculating separated particles into the reactor bottom section (3). Reactor (4), separator (5) and gas pass (7) are built as an integrated unit within one and the same cooling system. The boiler is controlled by maintaining the bed temperature substantially constant or within a relatively narrow temperature interval by regulating the recirculation rate dependent on boiler load. For regulating the recirculation rate a non-mechanical valve, preferably a so-called L-valve (8), is used.

Abstract: A method of operating an adiabatic fluidized bed reactor, and an adiabatic fluidized bed reactor, including the step of providing pressurized air to an adiabatic fluidized bed reactor both through openings located in a support surface and through openings located in the reactor walls having outlets below the surface of the bed of granular material. The structure of the adiabatic fluidized bed reactor includes support surface air distribution nozzles extending through a support surface, reactor wall air distribution openings extending through the reactor walls having outlets below the surface of the bed of granular material, and separate control valves for controlling the flow of pressurized air to the support surface air distribution nozzles and to the reactor wall air distribution openings. The method and apparatus of the present invention result in higher reactor hydrodynamic turndown ratios than can be achieved with conventional single-bed reactors. For example, a hydrodynamic turndown ratio of 6.

Abstract: Fluidised bed combustor comprising a housing (10) and an air diffuser bed support arrangement (12, 14, 15, 16) disposed in the housing (10) to support and fluidise a bed of material (11) in the housing (10) in such a manner that there is formed in the bed (11), a combustion zone (17) in which material is burned. A feed zone (19) into which material of fuel to be burned may be fed and mixed with the material of the bed (11), an ash segregation zone (20) in which ash resulting from combustion may be at least partially separated from the bed material, and in which the diffuser (13, 14, 15, 16) is arranged to cause the bed material to circulate in operation from the combustion zone (17), through the feed zone (19), through the ash segregation zone (20) and back into the combustion zone (17). In a second mode a circulation takes place through the combustion zone (17), a drive zone (18) over and onto the surface (26) of the bed (11), partly into the feed zone (19) and partly back into the combustion zone (17).

Abstract: A furnace (10) in which bark or other cellulosic fuel (64) is burned on a traveling grate (24). Char (62) separated (48, 54) from the furnace exhaust gases is reinjected into the furnace beneath baffle plate (40) in such a manner that the raw bark (64) being introduced onto the grate forms a protective cover over the char (62) thus preventing the relatively light char particles from becoming reentrained in the gases before they are completely combusted.

Abstract: A fluidized bed combustion apparatus in which in the free-board above the bed at least one system of plates or baffles inclined with respect to the vertical is arranged so that at least one upwardly directed channel having internally at least one group of two opposed arrays of superimposed inclined plates is formed, which plates at least alternately extend obliquely downwardly from the outside to the inside and are closely connected with the outer boundary of the channel. Preferably all plates of each array extend obliquely downwardly at an angle with the vertical within 20.degree.-50.degree. from the outside to the inside from a vertical wall defining said channel whereas the plates of the one array are off-set over a distance "s" in the vertical direction with respect to the plates of the other array.

Abstract: A fluidized bed combustor is utilized as a source of drains, including spent calcium-based sorbent. The reacted sorbent is broken to expose unreacted portions which can be recycled to capture additional sulfur compounds. A separation is provided by a magnetic separator and an electrophoretic separator in order to obviate the load of recycling reacted sorbent and other waste material having no calorific value.

Abstract: A fluidizing feed apparatus (20) for supplying particulate material to a fluidized bed furnace (12). A housing (22) defines a chamber which is divided by a perforated distribution plate (24) into a gas plenum (26) beneath the plate and a particulate fluidizing plenum (28) above the plate. Conveying gas is fed under pressure to the gas plenum to pass upwardly therefrom through the perforated distribution plate. The upwardly directed conveying gas fluidizes the particulate material so as to establish a discrete bed (60) of fluidized particulate material superadjacent the distribution plate (24) and a splash zone (70) thereabove. Transport conduits (14) open into the splash zone (70) at a selected distance above the surface (65) of the discrete bed (60) to receive particulate material and conveying gas therefrom for transport to the fluidized bed (16) of the furnace (12).

Abstract: In a tube boiler, fuel is burned in a fluidized bed which has a shallower part and a deeper part. The tubes extend only through the shallower part which can be fluidized independently of the deeper part so that the rate of heat transfer from the bed to the tubes can be varied according to demand. Water flows through specially configurated, upwardly oriented tubes by natural convection. There is also a general circulation of particles within the bed.

Abstract: A nozzle for a fluidized bed firing system in which a pipe for transporting coal/air mixture has an end surrounded by a hood. This pipe extends into the fluidized bed, and an axial exit opening is located between the hood and the pipe. The pipe, moreover, is provided with that axial exit opening, while the hood is spaced from this exit opening. A deflecting face, moreover, is located in a vicinity opposite to the exit opening. A downwardly-pointing baffle is attached underneath a lower edge of the hood, to the pipe so as to be adjustable in height. The deflecting face may be in the form of a cone with a tip pointing towards the exit opening of the pipe. The hood may be provided, furthermore, with a hemispherical cap.

Abstract: A combustion boiler is described for use with low quality feedwater. A combusting fluidized bed is circulated through a substantially vertical elongated combustion chamber in an upward path from the lower end of the combustion chamber to the upper end. A single layer of a tubular fluid conduit surrounds the outer periphery of the combustion chamber. The configuration is such that an ascending helical flow path is provided for fluid passing therethrough. This configuration is designed to minimize solids decomposition leading to the tube burnout.

Abstract: The carbon content of the residue from combustion of agricultural waste products is controlled and the fly ash content of the gaseous exhaust minimized by utilizing a portion of the combustion supporting air to enhance fluidization of the waste products above a fixed bed while being agitated by a rotating sweep arm inducing radially outward movement toward a residue collecting zone from which a sweep arm paddle displaces the residue into a discharge duct. The waste product feed is conveyed at a uniform weight flow rate to a central location in the combustion chamber above the bed from which of the feed is dropped onto the bed.

Abstract: Process and apparatus for the combustion of coke present on solid particles from which hydrocarbons have been substantially removed by heating, and for the production of recoverable heat from hydrocarbon-bearing solid particles, in a series of at least two combustion stages.

Abstract: The invention describes a process wherein high-purity hydrogen and oxygen gases can be economically produced via a water electrolysis method, utilizing cheap energy recovered from an incineration process of industrial, municipal, agricultural and other waste materials in a fluidized-bed incinerator. In the said process combustible solid and/or liquid wastes with high energy content are exploited to supply the energy required to incinerate and decompose other solid or liquid wastes with lower or no energy content. Also the process provides a method wherein any solid, liquid or gaseous emissions or effluents from the process are effectively trapped, controlled and converted to environmentally acceptable, inert and harmless products. Also the process includes an energy recovery system such that the thermal energy from the incineration is used to produce steam and generate electricity required for all operations in the process including the production of oxygen.

Abstract: The invention comprising a drying and sorting apparatus for preparation of solid fuel and other solid materials having substantial surface moisture. Ambient air/gas is preheated by indirect heat exchange or other unfired means sufficiently to provide heat needed by the downstream process. The air/gas is then passed up vertically through a bed containing the solid materials, heating and fluidizing them along with the surface moisture. When in a fluidized state, the smaller/lower density particles rise to the top of the bed. At least a portion of the surface moisture on the particles is evaporated. The quantity and temperature of the air/gas flow is sufficient to retain the evaporated surface moisture in the vapor phase. Feedstock of solid materials is added to an intermediate location of the bed. The larger/more dense fluidized particles are removed from bottom location/s of the bed. The smaller/less dense fluidized particles are removed from top location/s of the bed.

Abstract: The invention comprising a drying and sorting apparatus for preparation of solid fuel prior to firing in a combustion furnace. Unsaturated air/gas is passed through a bed containing a mixture of solid fuel and inert material particles, fluidizing them. The unsaturated air/gas is the drying vehicle. When in a fluidized state, the lighter organically derived solid fuel particles separate from the heavier inert material particles. The air/gas is admitted to the bed directionally in a manner which drives the mixture in a retraceable path to outlet points downstream of the point of feedstock entry, the heavier inert material settling at the bottom and the lighter solid fuel particles rising in the bed. Means are provided in the sorter floor for selectively concentrating and directing the solid inert material to the collection point transversely to the direction of particle flotation.

Abstract: The specification describes arrangements in which the attemperation or control of the temperature of a fluidized bed in a fluidized bed combustion unit effected by means of the mixture of a variable proportion of inert gas with fluidizing air fed to the bed may be supplemented with steam. Supplementation with steam being effected to a relatively minor extent during normal operation of the unit but being effected to a major extent when the temperature of the bed passes outside the range at which attemperation may be effected by use of recycled flue gas. The combustion unit is described in use within an arrangement including process plant in the form of a rotary drum dryer.

Abstract: A method and system for injecting coal and process fluids into a fluidized bed gasification reactor. Three concentric tubes extend vertically upward into the fluidized bed. Coal particulates in a transport gas are injected through an inner tube, and an oxygen rich mixture of oxygen and steam are injected through an inner annulus about the inner tube. A gaseous medium relatively lean in oxygen content, such as steam, is injected through an annulus surrounding the inner annulus.

Abstract: A fluidized bed gasifier (10) for gasifying a first fuel (50) receives heat indirectly from a combusting fluidized bed (24) disposed at least partially within the gasifier fluidized bed (12). Fuel for the combusting bed (24) may be provided by removing a portion of the fluidized first fuel from the gasifier bed (12) and transporting (30,34) this removed portion into the combusting bed (12). Heat is transferred across the conductive walls of the combustor vessel (26). Product gas heating value is increased by separately removing (28) the products of combustion from the gasifier (10) and by recycling a portion of the product fuel gas (74) as the fluidizing gas (54) for the gasifier fluidized bed (12). A radiation shield (18) is also provided to reduce heat loss from the gasifier bed (12) and to remove elutriated material from the product fuel gas.

Abstract: A fluidized bed combustion system for burning fuel particles, such as coal. The system includes a housing defining a first combustion region. An endless, flexible, perforate belt is shiftably mounted in the housing for supporting coal particles of relatively large size. A blower below the belt creates fluidized air which entrains smaller coal particles in a fluidized bed above the larger coal particles. The combustion gases arising due to combustion of the coal particles passes through a secondary combustion region in which coal fines are burned. The combustion gases continue upwardly through a scrubber in which limestone particles are entrained in the combustion gases to strip sulfides therefrom. The limestone particles are regenerated by a cyclone separator while the combustion gases travel through a passage containing boilers or other heat exchangers, whereby the heat from the combustion gases is transferred to fluids in the boilers.

Abstract: A reactor in which a plurality of vertical panels are disposed in a vessel and are constructed and arranged so as to form three combustion cells. Three of the panels each form a common wall between adjacent cells, and each cell is heated by a fluidized bed.

Abstract: A process for the calcination of a solid pulverulent material comprises the steps of gasifying a solid fuel in a fluidized bed to produce an ascending current of gaseous fuel, and injecting the material in an oxidizing carrier gas into the ascending gaseous fuel current above the fluidized bed of solid fuel to disperse the pulverulent material in the gaseous fuel current, the flow velocity of the gases in the zone of injection of the material into the current being sufficient to entrain the material in the gases and to prevent them from falling into the fluidized bed. An apparatus for the calcination comprises a calcination chamber whose bottom is a grid carrying a bed of solid fuel through which air is blown to produce the ascending current of gaseous fuel in the chamber. An array of nozzles in an upper portion of the chamber is used to inject the pulverulent material suspended in the carrier gas into the chamber above the fluidized bed.

Abstract: A fluid bed combustor comprising a plurality of fluidized bed stages interconnected by downcomers providing controlled solids transfer from stage to stage. Each stage is formed from a number of heat transfer tubes carried by a multiapertured web which passes fluidizing air to upper stages. The combustor cross section is tapered inwardly from the middle towards the top and bottom ends. Sorbent materials, as well as non-volatile solid fuels, are added to the top stages of the combustor, and volatile solid fuels are added at an intermediate stage.

Abstract: A centrifugal spreader type feeder that supplies a mixture of particulate limestone and coal to the top of a fluidized bed reactor having a flow of air upward therethrough. Large particles of particulate matter are distributed over the upper surface of the bed to utilize the natural mixing within the bed, while fine particles are adapted to utilize an independent feeder that separates them from the large particles and injects them into the bed.

Abstract: The present invention is directed to a fluidized-bed combustion apparatus provided with a U-shaped combustion zone. A cyclone is disposed in the combustion zone for recycling solid particulate material. The combustion zone configuration and the recycling feature provide relatively long residence times and low freeboard heights to maximize combustion of combustible material, reduce nitrogen oxides, and enhance sulfur oxide reduction.