Abstract: A method of attaining a uniform flow in an elongated fluidized bed furnace, used for the purpose of preventing the expansion and uniting of bubbles in the fluidized bed, and setting the fluidized bed in a uniform flow state, so as to keep the flow condition of the bubbles excellent at all times. The purpose of this method can be achieved by withdrawing a fluidized gas from an arbitrary portion of a fluidized bed (13) through a fluidization gas venting or purging means (A).

Abstract: An apparatus for powder falling type gas-solid contacting operation which comprises a hopper for feeding solid particles, a fluidizing bunker wherein the fed particles are fluidized by introduction of a fluidizing gas, a standpipe provided between the hopper and the bunker for feeding the particles from the hopper to the bunker, the lower end of the standpipe being located in the bunker, and a vertical gas-solid column connected to the bottom of the bunker for bringing the particles falling down from the bunker into contact with a gas countercurrently, in which a vertical tube is provided in the bunker so as to surround at least the lower end part of the standpipe and extend to a position below the lower end of the standpipe, whereby the height of the fluidized bed of the particles in the bunker is stably kept constant and the particles are fed from the bunker to the gas-solid column at a constant rate.

Abstract: A process for transferring and regulating the recycle of particulate solids separated from a gas-particulate solids suspension in which an auxiliary vesssel and slanted pipe are provided to transfer and regulate particulate solids flow.

Abstract: A fluidized bed heat exchanger and a method of controlling same in which a first chamber and plurality of additional chambers are formed in a housing. A particulate material is supported in all of the additional chambers and air is introduced to each of the additional chambers to fluidize the material. Particulate material is introduced into one of the chambers and the chambers communicate to permit the material to flow between the chambers. Heat is extracted from one or more of the other additional chambers and the material upon exceeding a predetermined height flows from the other additional chambers to the first chamber before discharging via the first chamber externally of the housing.

Abstract: At a fluidbed furnace comprising a combustion shaft, a particle separator, a particle return passage and designed according to conventional design criteria for obtaining a good combustion at moderate temperature, a destruction of laughing gas (N.sub.2 O), and complete combustion of possible unburnt particles in the combustion gases is brought about in a reactor passage at the entrance of which a combustion means is located. The reactor passage is moderately cooled, so the increase of temperature in the combustion gases is maintained substantially constant unto the first convection heating surface.

Abstract: Some part (a) of the bed material is withdrawn continuously (9e, 10) from the lower region of the fluidized bed (20), cooled (11), screened (12, 13) on a belt (a') to obtain a particle size specific to the fluidized bed, and then recycled to the fluidized bed (15, 18).

Abstract: A fluidized bed reactor in which a bed of particulate material including fuel is formed in a furnace section. Air is passed through the bed at a velocity to fluidize said material and promote the combustion of the fuel. A cooler is located adjacent the vessel for receiving particulate material from the vessel and for removing heat from the material. Drain pipes are provided in the furnace section and in the cooler for selectively removing particulate material from the furnace section and the cooler.

Abstract: A fluidized bed steam generating system in which a duct is disposed between a furnace outlet and a separator inlet. The duct is formed by first and second wall panels which are comprised of a plurality of parallel tubes extending perpendicular to the direction of the flow of the combustion gases. The tubes comprising the wall panels are bent and welded to a fin extending from corresponding portions of adjacent tubes to form a gas tight structure. The ends of the tubes are connected in fluid flow communication with first and second headers which enables cooling fluid to flow through the tubes for recovering heat from the combustion gases as they flow from the furnace into the separator.

Abstract: A fluidized bed reactor generating heat has in its bottom part a grid for introduction of fluidizing gas into the rector and walls being made as waterwalls in which vertical water tubes are combined by flat plate material. The waterwalls are refractory lined in their lower part to withstand erosion and heat. The water tubes are bent outwards at an angle to the vertical plane in the intermediate section between the uncovered upper waterwall section and the refractory lined lower waterwall section in order to minimize erosion due to particles flowing downwards along the walls in the reactor.

Abstract: A method and apparatus are provided for effecting bidirectional feeding of particulate material, such as in the bidirectional feeding of fuel to a circulating fluidized bed combustor. A feeder has a housing with at least one inlet in the upper portion of the housing and a chain and flight (drag chain) conveyor disposed within the housing. An intermediate plate is disposed between the upper and lower runs of the chain and flight conveyor and cooperates with the flights in the upper run so that the upper run conveys solid material in a first direction along the intermediate plate. A bottom plate is disposed below the lower run and cooperates with the lower run flights to convey solid material in a second direction opposite the first direction. First and second outlets are provided for the solid material, the first outlet at one end of the housing, and the second outlet at the other end of the housing.

Abstract: A stationary weakly expanded fluid bed for combustion of coal, refuse, sludge and the like has a free space above the fluid bed in which a so-called upper firing is effected with secondary air. The temperature of the secondary air is maintained above the temperature of the fluid bed to handle problems resulting from variations in fuel quality and varying loads and guarantees a stable upper firing.

Abstract: A fluidized bed combustion method in which a recycle heat exchanger is located adjacent the furnace of the combustion system. A mixture of flue gases and entrained particulate materials from a fluidized bed in the furnace are separated and the flue gases are passed to a heat recovery section and the separated particulate material are passed back to the furnace. The walls of the furnace are formed by water tubes, and refractory metal material is placed adjacent the walls to control the heat absorption by the water passing through the tubes. The amount of refractory is selected in accordance with the desired operating temperature of the furnace.

Abstract: A combustion unit for a circulation process comprises a reactor chamber and at least one particle separator placed inside the reactor chamber in the upper part thereof. At least the first outer casing of the particle separator is arranged to form a heat transfer surface. A flue gas inlet into the first outer casing is arranged to extend for the entire circumference of the casing.

Abstract: A rotary fluid bed gasifier which comprises: a rotatable drum having a circumferentially extending wall which is permeable to gases; a means for feeding a fluidizing gas through the wall into the drum; a bed of particles which, at least when the gasifier is in use, is supported on an internal face of the wall and is fluidized by the fluidizing gas; an outlet means for receiving a carbonaceous material from outside the gasifier and delivering the carbonaceous material to the drum; a means for introducing steam into the drum; a de-NO.sub.x boiler having a quench zone and a nitrogen fixing zone; a means for introducing secondary air disposed between the quench zone and the nitrogen fixing zone; and a means for introducing tertiary air disposed between the de-NO.sub.x boiler and a main boiler or furnace.

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, via an outlet chamber, 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 for heating the fluid flow circuit and reducing the temperature of the separated material. The separated material in the heat exchange chamber is then passed back, via the outlet chamber, to the furnace section.

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 recycle heat exchange section. The recycle 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 is provided in the recycle heat exchange section to transfer heat from the separated material in the recycle heat exchange section to a fluid flow circuit for heating the fluid flow circuit and reducing the temperature of the separated material. The separated material of the recycle heat exchange section is then passed back to the furnace section.

Abstract: A method and a reactor for combustion of solid granular fuel material in a fluid bed by means of primary air supplied to the bottom of said reactor and by secondary air supplied a distance above the reactor bottom, solid granular fuel material which is falling along the boundary side wall of the reactor being collected in at least one pocket arranged in the direction in which the material is falling, a cooling surface being arranged in said pocket.

Abstract: A fluidized bed combustion system and method in which a recycle section is located integrally with the furnace section in an enclosure and operates as a combustor. Heat exchange surfaces are provided in at least one compartment of the combustor/heat exchanger for removing heat from the solids, and a bypass compartment is provided through which the solids directly pass to the furnace during start-up and low load conditions. Fluidizing air is discharged at the internal recirculation of the solids and a partition is located in the central portion of the furnace enclosure for introducing secondary air.

Abstract: A furnace, especially a fluidized furnace with a combustion chamber (1) that gas flows up through and that has a gas outlet provided with a second flue (2) and a precipitator (10) for separating solids from the flue gas. The solids end of the precipitator communicates with the second flue, which accommodates a layer (12) of solid matter. The bottom of the second flue communicates by way of a solids-reintroduction line (14) with the combustion chamber. The second flue is a solids cooler and the precipitator is also a filter.

Abstract: A control circuit (B) is adapted the steam pressure at a boiler drum (17) which receives heat from a incineration chamber (3) in a fluidized bed type boiler (A, C) to be correlated to the thermal energy to be recovered and transferred to the boiler drum and to improve a responsiveness for the suppressed control of increase or decrease of the steam pressure caused by variation of a steam load. The velocity of heat recovery is controlled in accordance with the steam pressure in the boiler drum (17) which is detected by a pressure gauge (20b) and a combustibles supply unit (12, 13, 14) for supplying combustibles to the boilers (A, C) is also controlled accordingly.

Abstract: A process and apparatus is presented for the reduction of nitrous oxide in the effluent from the combustion of a carbonaceous fuel. The process comprises raising the temperature of the effluent to a temperature of at least about 1700.degree. F. The apparatus utilized is a heating means which is disposed in a boiler at a location where the effluent is at a temperature of less than about 1700.degree. F.

Abstract: An improved fluid-bed reaction apparatus is disclosed in which feedstock is preheated and may be at least partially converted by contacting the feedstock with spent catalyst in a preheat zone. Additional benefits include a reduction in catalyst poisons and coke production in the reaction zone. By contacting the fresh feed with hot spent catalyst, at least a portion of the coke which would otherwise form in the reactor is deposited on the spent catalyst. Temporary catalyst poisons are also sorbed onto the spent catalyst. The spent catalyst is then withdrawn from the preheat zone, stripped of entrained hydrocarbon and regenerated.

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: 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: 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: A method and apparatus for cooling hot FCC catalyst particles in a heat exchange zone that is separate and distinct from the regenerator having an upper portion that operates in a flow-through mode and a lower part that operates in a back mix mode. Catalyst descends from a collection zone into an upper inlet of a heater exchanger. The exchanger contains a series of tubes for indirect heat exchange of the catalyst with a cooling fluid. Catalyst leaves the exchanger through an outlet located at a mid portion of the exchanger. The section of the exchanger between the inlet and outlet comprises the flow-through portion. Catalyst undergoes further heat exchange below the outlet of the exchanger in the backmix portion. Fluidizing gas that enters at the bottom of the exchanger provides the necessary turbulence for particle interchange in the backmix section of the heat exchange zone as well as transport of the particulate material through the flow-through portion of the exchanger.

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 reactor in which a furnace and a heat recovery area are provided. 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. The products of combustion (or flue gases) pass upwardly through the furnace and transfer heat energy to the walls thereof to produce steam. Flue gases leaving the upper region of the furnace section are transported to a heat recovery area, which functions to remove additional heat energy from the flue gases for producing the steam. A flue gas by-pass system is provided which transports relatively hot flue gases from a lower region of the furnace section to the heat recovery area for improving isothermal operating conditions and optimizing reactor performance. One or more conduits pass flue gases directly from selected extraction points within the lower region of the furnace to an upper portion of the heat recovery area.

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: 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: 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: A fluid-bed combustion reactor (51) comprising a substantially vertical reactor chamber with a first inlet (9) at the reactor chamber lower portion (52) for the introduction of liquid and/or solid particulate material, and a second inlet (22) at a level below the first inlet for the introduction of gas for fluidization of particulate material within the reactor in order to maintain a primary fluid bed, an exhaust duct (28) at the reactor chamber upper portion for the withdrawal of exhaust gas and particles from the reactor, and a fluid-bed cooler (42) for particular material, formed as an upwards open vessel with generally closed bottom and side walls and arranged so as to collect a portion of particulate material (64, 65) from the reactor chamber upper portion, said cooler comprising heat transfer means (43) such as tubes carrying a heat transfer medium at the inside and having said particulate material flowing at the outside, said cooler comprising at least one conduit (56) for the controlled returning of p

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: 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 parameter, especially the temperature of the bed in a fluidized-bed furnace, is maintained constant by a regulator (24) positioned in a line (20) that supplies fluidizing air to a trap (15), through which solids that have been precipitated out of the flue gas are recirculated into the fluidized bed (5). The servo mechanism (23) that drives the regulator is coupled to a temperature sensor (27) in the bed such that the volume of fluidizing air is increased when the measured bed temperature exceeds a prescribed level and decreased when it drops below that level.

Abstract: The known pulverized coal combustion method including the steps of separating pulverized coal mixture gas ejected from a vertical type coal grinder into thick mixture gas and thin mixture gas by a distributor, and injecting these thick and thin mixture gases, respectively, through separate burner injecting ports into a common furnace to make them burn, is improved so as to reduce both an unburnt content in the ash and a nitrogen oxide concentration in exhaust gas while maintaining an excellent ignition characteristic. The improvements reside in that an air-to-fuel ratio of the thick mixture gas is regulated to within the range of 1-2, while an air-to-fuel ratio of the thin mixture gas is regulated to within the range of 3-6, and the range of a degree of pulverization of the pulverized coal is regulated to 100 mesh residue 1.5% or less.

Abstract: The generation of clinker ash from exhaust gas dust in a boiler, furnace or the like which employs dust coal as a fuel can be controlled with excellent results by adding to a fuel at least one iron compound in a relatively small amount, and, preferably, at least one compound of a metal selected from the group consisting of Cu, Mn, Co, Ni and Cr, and, preferably, at least one compound of a metal selected from the group consisting of an alkali metal and an alkaline earth metal, in the form of an aqueous solution or a water slurry in which the particles are capable of passing through a 100-mesh screen.

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: 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 gas and steam turbine power plant has a gas turbine with a gas side, a waste heat steam generator having a steam side and being connected downstream of the gas side of the gas turbine, and a steam turbine connected to the steam side of the waste heat steam generator. A super-charged, coal-fired steam generator has an exhaust gas vent line connected to the gas turbine. The coal-fired steam generator includes at least one substoichiometrically operated fluidized bed furnace system, an integrated dust separator connected downstream of the at least one fluidized bed furnace system, and a steam generator slag tap or wet tap furnace having burners with a gas side connected downstream of the dust separator.

Abstract: A jet stream injection device for use in a heat exchanger of a fluidized-bed type in which a flat jet stream is injected toward a heat transmission coil of the heat exchanger from below this coil so that is runs along said cell so as to form a mixed-phase flow of a gas and solid particles around the heat transmission coil. The jet stream injection device has a net with meshes smaller than the size of the particles of a fluidized bed provided over an opening provided on the upstream side of a jet stream generating slit-shaped injection port element. The opening has a larger passage sectional area than the injection port element.

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: An apparatus for gasifying solid carbonaceous material in a circulating fluidized bed reactor. Particles are separated from the product gas at least in two stages so that in the first stage mainly coarser, so-called circulating particles are separated and returned to the reactor. In the second stage fine carbonaceous and ash-containing particulates are separated from the gas and are made to agglomerate at a raised temperature. Coarser particles thus received are returned to the reactor through a return duct together with circulating particles. Agglomeration is effected in a chamber where a fluidized bed composed of coarse particles is maintained. Fine particulate material and oxygen containing gas are introduced into the free upper part of the chamber so as to form a hot flame (e.g. 1200.degree. C.). The point of the flame penetrates into the fluidized bed. The ash material contained in the fine particulate material melts, and is conducted to the bubbling fluidized bed.

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: 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 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 fired heater in which at least a portion of a tube extends within an enclosure and receives fluid from a manifold disposed externally of the enclosure via a conduit. At least a portion of the conduit extends within the enclosure so that, when heat is applied to the enclosure for heating the fluid the fluid in the conduit is preheated.