Abstract: A method for controlling combustion in a furnace into which combustible material, e.g., urban refuse, industrial waste, and a controlled quantity of combustion air are fed. The furnace includes a mixing/stirring region where unburnt gas and secondary combustion air are mixed and stirred. A part of exhaust gas derived from the furnace is blown into the mixing/stirring region depending on variation in the quantity of the secondary combustion air, and a flow rate of mixture gas consists of the exhaust gas and the secondary combustion air to be fed into the mixing/stirring region is maintained within a predetermined region so that effective combustion takes place.

Abstract: A fluidized bed combustion system and method in which a recycle heat exchange section is located within an enclosure housing the furnace section of the combustion system. The flue gases and entrained solids from a fluidized bed in the furnace section are separated and the flue gases are passed to a heat recovery section and the separated particulate material to the heat exchange section. The heat exchange section includes a bypass chamber for permitting the separated solids to pass directly from the separator to the furnace section. A heat exchange chamber is provided in the recycle heat exchange section which receives the separated materials from the bypass chamber and transfers heat from the separated material to a fluid flow circuit. The separated material in the heat exchange chamber is then passed back to the furnace section.

Abstract: In a fluidized bed thermal reactor. It includes a main housing including a waste inlet, an exhaust gas outlet, an incombustible solids outlets, a base member, a fluidizable medium located on the base member, a plurality of gas inlets in the base member.

Abstract: A fluid bed processing apparatus in which a series of individual fluid bed modules are arranged horizontally alongside each other in a linear or circular configuration with the bed material overflowing weirs between each module in moving from the feed stock input module to a discharge module.

Abstract: A fluidized bed combustion system and method for combusting particulate fuel such as coal together with a sorbent material such as limestone to heat a pressurized liquid and generate saturated vapor, such as steam. The combustion system utilizes at least one concentric dual-sided riser-downcomer unit having a central riser passageway and a concentric outer downcomer passageway located above a dense phase fluidized bed in an enclosure module, the downcomer being configured for directing particulate solids back to the bed. The unit inner and outer passageway surfaces each include a heat exchange panel containing the pressurized liquid for absorbing heat from combustion of the fuel and generating the vapor such as pressurized steam. Primary air is provided below the fluidized bed, while secondary air is provided into the riser passageway.

Abstract: The present invention relates to the refractory lining covering the lower part of a tube wall in the reactor chamber of a fluidized bed reactor. The upper surface or edge of the refractory lining is provided with a plurality of radial grooves to guide the bed material flowing downwards along the walls so as to decrease its wearing effect at the border line of the refractory lining and the tube walls.

Abstract: The invention relates to a method and a nozzle bottom for controlling the mixing of gaseous flows in fluidized bed reactors and circulating fluidized bed reactors. In the method, part of the combustion air is introduced into a reactor chamber through fluidizing nozzles (11) positioned in a nozzle bottom (4). In order to improve the controllability of a combustion process, the remaining part of the combustion air is according to the invention introduced through essentially vertically directed jet nozzles (12) positioned in the nozzles bottom (4), and the vertical penetration of the air jets applied through the jet nozzles (12) is maintained at a value essentially higher than the vertical penetration of the air jets applied through the fluidizing nozzles (11).

Abstract: A method and apparatus for burning carbonaceous materials in a fluidized bed reactor comprising a bottom region and a top region, and containing a fluidized bed, with the heat of combustion being dissipated at least via wall cooling surfaces, and comprising a recirculation system, including a labyrinth separator for recirculating the separated solids to the bottom region of the fluidized bed reactor. The solids are separated from the rising flow of flue gas by the labyrinth separator, which is disposed directly in the top region of the fluidized bed reactor, and are conveyed in the reactor itself along the wall cooling surfaces and are supplied to the bottom region of the reactor, either freely or in closed or partly or completely open recirculation passages. The main area of application is with a steam generator.

Abstract: A dewatering apparatus having a delivery zone and a drying zone separated by a weir is disclosed. The delivery zone is provided with a porous floor plus an associated drain and the drying zone has a vibrating porous surface above an associated plenum chamber. The plenum chamber is connected to a source of a hot gaseous fluid.

Abstract: A furnace for combustion wherein a combustion chamber is configured such that waste can be advanced from a drying zone, to a combustion zone, to a burnout zone, and then into an ash pit. An air source provides air for drying, combustion and burnout in a primary combustion zone (PCZ). Fuel or a fuel/recirculated flue gas mixture is injected above the PCZ to create a mostly reducing substoichiometric secondary combustion zone (SCZ), to reduce NO.sub.x and decompose other nitrogen bearing compounds entering the SCZ. Vitiated air is injected into the combustion chamber above the mostly reducing SCZ. A process for combustion of the waste includes introducing the waste into the combustion chamber, advancing the waste through the combustion chamber, supplying combustion air to the combustion chamber for drying and combusting the waste and final ash burnout, and removing ash products from the combustion chamber.

Abstract: A fluidized-bed incineration system is disclosed wherein complete combustion of fluctuating furnace charge is achieved through the use of an invented system that includes a feedback control apparatus to regulate the variable quantities of air required for treating fluctuating volumes of products of combustion processes; the combustion control is triggered by a feedback apparatus incorporating the computed measurements of radiative energy or furnace pressure in combination with dynamic oxygen measurements.

Abstract: An improved method for controlling combustion zone temperature in a furnace independent of flue gas oxygen content is disclosed. The method comprises supplying a carrier gas containing a fine mist of liquid water droplets to the furnace combustion zone to control the maximum temperature within the combustion zone. The invention is applicable to both multiple hearth furnaces and fluidized bed furnaces, protecting the refractory furnace lining from damage.

Abstract: The combustion chamber for combusting finegrained fuels in a fluidized bed at temperatures from 700.degree. to 1100.degree. C. is provided with a refractory lining in the lower portion of the chamber on the inside surface of the watercooled wall. The lining is provided at its top end with a cornice, which is enlarged in width. The width of the cornice is preferably at least 1.5 times the wall thickness of the brick lining below the cornice.

Abstract: The grid plate is disposed between the fluidized bed reactor chamber and an underlying wind box and includes a plurality of nozzles for feeding fluidizing gas from the wind box into the reaction chamber. The nozzles are configured to afford different pressure drops across the grid such that with increasing pressure, additional nozzles are actuated in response to increasing pressure differences across the plate whereby fluidized bed start-up and steady state operating conditions may be facilitated.

Abstract: Where as-mined coal or a washed coal derived therefrom is burned in a pulverized coal-fired boiler, improvements both in the utilization of the overall fuel values of the as-mined coal and in the operating efficiency of the boiler are obtained by installing a fluid bed combustor in the same combustion chamber as the pulverized fuel burner system of the boiler, and preferably below the burner system, and supplying as the fuel to the combustor a fuel comprising coal washery tailings preferably mixed with high ash solid washery residue.

Abstract: An apparatus and method for recovering constituents and/or heat energy from a fluidized bed combustion process utilizes a single vessel which combines a combustor for fluidized bed combustion of a chemical mixture fed therein and a heat exchange section. Characteristics of the fluidized bed are controlled by withdrawing an appropriate portion of the larger, unburned constituent particles from the bottom of the combustor, and smaller constituent particles are withdrawn by becoming entrained within the gases of combustion and being transported to the heat exchange section. The smaller particles are separated from the gases without the use of a cyclone separator and accumulate as another fluidized bed in the heat exchange section where heat is adsorbed from the particles for recovery purposes and to cool the particles. A portion of the cooled particles is then recirculated to the combustor by, for example, pneumatic transport methods for controlling the operating temperature of the combustion process.

Abstract: An apparatus to be applicable as a boiler for incinerating wet refuse in a combustion chamber with a fluid and heat medium of solid particles fluidized by an air feed to form a fluidized bed, with the aid of combustion of auxiliary fuel effected below the fluidized bed, is provided with additional one or more adjacent upper fluidized fed chambers in series to have the wet refuse dried and partially incinerated in the lower primary fluidized bed chamber with the balance of the refuse in a form of unburnt carbon particles being forced to fly upward into the additional upper fluidized bed chambers and be incinerated therein. Heat recovery is carried out from a topmost fluidized bed chamber.

Abstract: Apparatus for incinerating refuse or the like in a furnace where the flue gases of combustion are combined with secondary air for afterburning the gases in an afterburning zone. The flue gases are dammed before entering the afterburning zone so as to increase retention time of the flue gases in a zone of uniform temperature in the furnace space, then are accelerated in a venturi-like manner in the afterburning zone, and then are decelerated in a venturi-like manner in the afterburning zone. Secondary air is injected across the front of the afterburning zone in a direction opposite the flow of the flue gases so as to further increase the retention time of the flue gases in the furnace space, and so that the combustible components entrained in the flue gases are burnt completely before entering the afterburning zone.

Abstract: A process for thermal treatment of solid particles in a fluidized bed wherein the solid particles by thermal treatment form a lighter weight fraction and a heavier weight fraction, relative to the total contents of the bed. The process is characterized by use of a selective heavier particle discharge conduit in the sloping bed support and maintenance of a discrete fluid fueled flame in close proximity to and above the opening to the heavier particle discharge conduit. This forms a higher temperature zone in and surrounding the flame, at least about 100.degree. F. higher than the remainder bed temperature. Circulation of solid particles through the flame and its surrounding higher temperature region is promoted both by directing of fluidization gas jets in the fluidized bed support and by the jetting action of the upwardly flowing heavier particle discharge gas.

Abstract: A bubbling fluid bed steam generator comprising: a reactor chamber having a lower combustion region and a freeboard region; heat exchange means for the circulation of a coolant disposed substantially throughout the freeboard region and along the walls of the reactor chamber; discharge conduit disposed near the top of the reactor chamber for the discharge of flue gas containing entrained solid particles therein; a particle separator connected to the discharge conduit for separating the solid particles from the discharged flue gas, the solid particles being returned to the lower combustion region of the reactor chamber via a recycle port; means for introducing a carbonaceous material to the lower combustion region of the reactor chamber; primary inlet means for introducing a fluidizing gas disposed at the bottom of the reactor chamber; and secondary inlet means for introducing a fluidizing gas disposed above the recycle port, wherein the improvement is characterized by: the lower combustion region of the reacto

Abstract: A boiler comprises a shell for fluid to be treated and divided into first and second heat exhange zones by at least one baffle, the zones being in communication with one another beneath a lower end of the baffle. Exhaust gases from a combustion source are supplied to a plurality of heat exchange tubes extending through each zone in heat exchange relationship with the fluid in the shell and being arranged in passes sequentially connected to one another whereby the exhaust gases pass sequentially through the first and second zones. The fluid to be heated is fed to an upper region of the second zone such that the temperature of gases passing through at least some of the tubes in the second zone falls to below the dew points of combustion products therein, the tubes in which condensation occurs being orientated such that condensates flow therefrom for disposal.

Abstract: A method for incinerating contaminated soil or other material utilizing an incinerator, such as a CBC, which is operated below atmospheric pressure and apparatus for carrying out such decontamination by delivering the soil to be processed in desired particulate size to the incineration unit, e.g., to a recirculation loop through which separated solids are being returned from a cyclone to a CBC. The system for supplying the contaminated soil is isolated from the chute leading to the incineration unit by a feeder that forms an agglomerated plug which serves as a pressure seal and prevents any gas flow therepast. Illustrated are a pair of twin counterrotating screws which include shafts that extend past the ends of the screw flights to locations where rotary cutters having multiple blades are mounted.

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.

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.

Abstract: A process and apparatus for fluidized bed combustion using a dense phase combustion zone over a dilute phase combustion zone. When used to regenerate FCC catalyst containing coke with relatively large amounts of NO.sub.x precursors, the catalyst is added to and partially regenerated in the dense phase zone and then falls down into the dilute phase zone. Most of the combustion air is added to the dilute phase and rises into and fluidizes the dense phase zone. NO.sub.x formed in the dilute phase is reduced to N.sub.2 in the dense phase.

Abstract: An incinerator has a furnace body whose height is 1.5-10 times the average internal diameter thereof. A combustion chamber is included which is formed by providing a plurality of air blast ports in a lower side wall and/or bank in the furnace body. A gas exhaust port is provided in the upper side of the combustion chamber and the side wall of the upper portion of the furnace body. A duct is included for leading an exhaust gas from the exhaust port to a place for making secondary use thereof.

Abstract: In a fluidized bed incinerator for burning matter to be incinerated charged into a furance by causing fluidization of a fluidizing medium with the assistance of air fed from the lower portion of a fluidized bed, a combustion control method is arranged such that: the combustion rate of matter for incineration in the furnace is detected by a combustion rate detecting means, and, when the combustion rate exceeds a predetermined level the amount of air fed from the lower portion of the fluidized bed is reduced; and, simultaneously, the amount of air blown into a space above the fluidized bed is increased so as to control and maintain the combustion rate of the matter to be burnt in the furnace at the predetermined level and to suppress fluctuations in the amount of combustion air, the amount of exhaust gas, the oxygen concentration in the exhaust gas and the amount of gas remaining unburnt or the like.

Abstract: A circulating fluidized bed combustion reactor and a process for combusting a solid hydrocarbon fuel in the same wherein fly ash recycling is utilized to regulate heat transfer and to minimize erosion of reactor operating components.

Abstract: An apparatus and method for recovering constituents and/or heat energy from a fluidized bed combustion process utilizes a single vessel which combines a combustor for fluidized bed combustion of a chemical mixture fed therein and a heat exchange section. Characteristics of the fluidized bed are controlled by withdrawing an appropriate portion of the larger, unburned constituent particles from the bottom of the combustor, and smaller constituent particles are withdrawn by becoming entrained within the gases of combustion and being transported to the heat exchange section. The smaller particles are separated from the gases without the use of a cyclone separator and accumulate as another fluidized bed in the heat exchange section where heat is adsorbed from the particles for recovery purposes and to cool the particles. A portion of the cooled particles is then recirculated to the combustor by, for example, pneumatic transport methods for controlling the operating temperature of the combustion process.

Abstract: Industrial, municipal, sanitary, marine, and infectious waste materials are thermally and chemically converted principally to steam, fuels and environmentally acceptable solids by dehydration, pyrolysis of the solid residue therefrom, and finally gasification of the pyrolysis char residue. In contrast to incineration processes, the products have significant market value and present no atmospheric pollution problems. Temperatures employed range up to about 3000.degree. F.

Abstract: An incineration apparatus and method for disposal of infectious hazardous waste including a fluidized bed reactor containing a bed of granular material. The reactor includes a first chamber, a second chamber, and a vertical partition separating the first and second chambers. A pressurized stream of air is supplied to the reactor at a sufficient velocity to fluidize the granular material in both the first and second chambers. Waste materials to be incinerated are fed into the first chamber of the fluidized bed, the fine waste materials being initially incinerated in the first chamber and subsequently circulated over the partition to the second chamber wherein further incineration occurs. Coarse waste materials are removed from the first chamber, comminuted, and recirculated to the second chamber for further incineration. Any partially incinerated waste materials and ash from the bottom of the second chamber are removed and recirculated to the second chamber for further incineration.

Abstract: A method for disposing by incineration of oil contaminated waste material after removal of solids of various kinds by performing multiple steps in its handling wherein the composite material is first subjected to a first classification step for extracting a high percentage of contaminant free material. After subjecting the material to a second classification cyclone where the gases that are used to transport the ground matter can be separated while the solids are subjected to classification by the use of a vibratory screen where the paper, fluffy waste, and similar material can be separated from the smaller and harder particulate components. The separated components are subjected to individual impact grinding steps prior to being recombined in the combustor where incineration takes place.

Abstract: A method for treating ash produced by waste coal fluidized bed boilers in which hot ash fines and heated secondary air are introduced into the boiler as the coarse ash is cooled. An ash treatment system for cooperation with a fluidized bed boiler operating on waste fuel having a high ash content receives and classifies hot ash from the boiler, returns ash fines to the boiler, cools coarse ash fines for disposal and burns carbon associated with the ash received from the boiler.

Abstract: The device for feeding fluidizing gas to the openings (1) in a fluidizing grid (2) comprises an end piece (4) fitted on each bottom inlet (3) to each opening (1) and having a length e lying in the range between 0 and 0.5 times the diameter d of the end piece, and a cup (5a) into which the end piece extends, with the bottom (6) of the cup being at a distance i from the end piece, which distance may optionally be adjustable. The entire device is housed in a fluidizing gas feed box (5).

Abstract: A fluidized bed combustion apparatus has a gas dispersion plate provided in a lower part of a fluidizing chamber on which fluidizing mediums are fluidized to form a fluidized bed in which a fuel is combusted. The apparatus further includes a porous ceramic member so mounted in a combusted gas outlet of the fluidizing chamber as to transverse the outlet. Coating materials having a high radiation rate are applied on an inner wall surface of the fluidizing chamber and on the porous ceramic member surface directed to the fluidizing chamber. The porous ceramic member is perforated with holes each having a diameter larger than a particle diameter of a fluidizing medium. The apparatus is equipped with a unit for back-washing the filter. The apparatus also includes a plate, provided downwardly of the filter, for capturing the particles scattered from the fluidized bed.

Abstract: A power plant with a combustion chamber in which a fuel in burned in a fluidized bed of a particular material, comprises a storage container for the bed material which, upon a load reduction, is removed from the combustion chamber. The storage container is provided with a sieve or a grate which prevents slag lumps formed in the bed material from penetrating into a conduit for the return of the bed material to the combustion chamber. A tube projecting into the storage container forms the sieve.

Abstract: The known method of burning solid fuel by means of a fluidized bed is improved so as to reduce the amount of generated NO.sub.x and to enhance the efficiency of combustion. Primary air, secondary air and tertiary air are respectively fed through a primary air feed port opening at the fluidized bed, through a secondary air feed port opening at a free board downstream of the fluidized bed and through a tertiary air feed port opening downstream of the secondary air feed port. The feed rates of the primary air, secondary air and tertiary air are respectively controlled so that the air ratios with respect to the theoretical amount of air after charging of the primary air, after charging of the secondary air and after charging of the tertiary air may become about 0.6-0.8, about 0.8-1.0 and about 1.0 or higher, respectively. Preferably, unburnt ash sputtered from the fluidized bed is recirculated into the fluidized bed.

Abstract: A fluidized-bed reactor composed of modular steel castings is assembled from a support frame, a sliding frame and reactor housing segments on the frames so as to be able to withstand the temperatures and temperature gradients to which the reactor may be subject.

Abstract: A method of incinerating all kinds of wastes such as municipal waste, waste plastics, industrial waste, various kinds of waste slurries and waste liquid, etc. or fuels such as coal, oil cokes and bark, etc. using a fluidized bed type incinerator which employs a granular material as a fluidizing medium, said granular material comprising TiO.sub.2 or Al.sub.2 O.sub.3, particularly anatase-type TiO.sub.2 or .alpha.-Al.sub.2 O.sub.3, as the primary component thereof.

Abstract: A system and method for controlling the sealing efficiency and recycle rate in a fluidized bed reactor in which air is introduced into two chambers found in a sealing vessel for receiving the separated solids from the separator. The air is introduced into two chambers in the sealing vessel in a direction opposite to that of the flow of the separated solids through the vessel. One of the chambers is located below the separator dipleg and in alignment therewith and the other chamber surrounds the first chambers. The air flow through each path can be separately adjusted as necessary.

Abstract: A reactor having a furnace and a heat recovery section. The upper portion of said furnace extends coaxially in a spaced relationship within a shell. A bed of solid particulate material including fuel is supported in the furnace and air is introduced into the bed at a velocity sufficient to fluidize same and support the combustion or gasification of the fuel. A mixture of air, the gaseous products of combustion, and the particulate material entrained by the air and the gaseous products of combustion are discharged through a plurality of slots and arcuate arms disposed at the upper portion of the furnace onto the inner wall of the coaxial shell, effecting a separation of the particulate material from the mixture. The remaining mixture of air and the gaseous products of combustion rise upwardly and are directed to the heat recovery section. The separated particulate material is directed from the coaxial shell to a plurality of recycle conduits.

Abstract: A reactor in which a bed of particulate material including fuel is formed in one of two sections in a vessel. Air is passed through the bed at a velocity to fluidize said material and promote the combustion of the fuel. The air and the combustion gases mix and entrain a portion of the particulate material, and pass from the one section to the other section. A plurality of spaced parallel water tubes are disposed in the path of the mixture and entrained particulate material as they pass through the other section to separate the entrained particulate material from the mixture.

Abstract: A fluidized bed gas-solids contact reactor, which utilizes at least one capped concentric dual-sided riser-downcomer unit having a central inner riser passageway and a concentric outer downcomer passageway. The riser-downcomer unit is usually located above the fluidized bed, and is adapted for directing the downflowing solids back into the fluidized bed for recycle. The reactor unit inner and outer passageway surfaces include a heat exchange panel having inner and outer channels each containing a circulating liquid. Particulate solids from the dense phase fluidized bed are continuously circulated in dilute phase through the riser-downcomer unit passageways by a reactant gas to exchange heat with the liquid. The particulate solids can be a catalyst or a fuel material. The invention also includes a combustion system and method for combusting a particulate fuel such as coal in air to generate pressurized saturated liquid for producing saturated steam.

Abstract: Process and apparatus for incinerating refuse or the like in a furnace where the flue gases of combustion are combined with secondary air for afterburning the gases in an afterburning zone. The flue gases are dammed before entering the afterburning zone so as to increase retention time of the flue gases in a zone of uniform temperature in the furnace space, then are accelerated in a venturi-like manner in the afterburning zone, and then are decelerated in a venturi-like manner in the afterburning zone. Secondary air is injected across the front of the afterburning zone in a direction opposite the flow of the flue gases so as to further increase the retention time of the flue gases in the furnace space, and so that the combustible components entrained in the flue gases are burnt completely before entering the afterburning zone.

Abstract: In a fast fluidized bed reactor having, in a lower region, downwardly and inwardly inclined walls, a change in the direction of the wall surface or a ledge or protrusion is provided to change the direction of the particles flowing downwardly adjacent the wall for directing the particles inwardly away from the wall and into the region acted on by the nozzles providing the fluidizing gas. The change of direction, abutment or projection is preferably provided along the refractory wall surface at an elevation 200-1100 mm above the grid plate. In this manner, clogging of the nozzles is prevented and more efficient and effective fluidization and combustion processes occur.

Abstract: A process for combustion of ion-exchange resin which comprises introducing an ion-exchange resin and air into a fluidized bed reaction zone which is heated to initially combust said resin and thereafter contacting soot and other unburned materials from said fluidized bed reaction zone, in a region above the fluidized bed reaction zone, with a catalyst to effect further catalytic combustion.

Abstract: A thermal reactor which utilizes a fluidizing bed includes a thermal energy recovery chamber having a heat exchanger therein. Fluidizing medium disposed in the fluidizing bed is supplied into the thermal energy recovery chamber due to circulation of the fluidizing medium within the fluidizing bed. The fluidizing medium is passed through the thermal energy recovery chamber such that thermal energy present in the fluidizing medium is transferred to the heat exchanger.

Abstract: This invention pertains to a segmented insert installed within the horizontal conduit of a non-mechanical means (such as an L-valve) for controlling the external flow of particulate material recycled to a fluidized bed combustor. The segmented insert is insulated to protect the horizontal conduit and the individual segments are joined together by a combination of a collar and hinge means. This method of coupling retains the co-axial alignment of the individual segments for leak-free operations while also enabling them to move or pivot independent of each other while still being connected together. Such independent movement is necessary for stress release purposes during high temperature operation.

Abstract: Heat generator comprising a combustion chamber, a circulating bed and a recovery boiler. The circulating bed and the combustion chamber have a common wall. The present invention may be used to achieve the combustion of high sulphur content fuels.

Abstract: A fluidized bed reactor in which a bed of solid particulate material including fuel is provided in a furnace section and air is introduced into the bed at a velocity sufficient to fluidize the particulate material and support the combustion of the fuel. A separator separates the entrained particulate material from a mixture of the air and the gaseous products of the combustion. The separator is connected to the furnace section for returning the separated particulate material back to the bed. Relatively coarse sorbent and relatively fine sorbent material are passed into the furnace section at two separate locations, respectively.