Abstract: A method of burning coal with less than 10% volatiles in a burner supported by air. The coal is pulverized in a pulverizer and supplied to the burner mixed with a vehicle in the form of air. The object is more reliable ignition. The coal is separated from the air before it enters the burner and is combined into a new mixture with heated air. The second mixture is forwarded at a higher temperature and with a lower level of coal. The coal is separated from the second mixture and combined into a third mixture with heated air. The third mixture is forwarded at a higher temperature and with a higher level of coal.

Abstract: A fluidized bed combustion system in which a separator receives a mixture of flue gases and entrained particulate separated material from a fluidized bed in a furnace. A pressure seal valve connects an outlet of the separator to the furnace or a fluidized bed heat exchanger disposed adjacent the furnace for recycling the separated particulate separated material back to the furnace. The pressure seal valve includes a downflow leg, and upflow leg and a horizontal leg connecting the downflow leg to the upflow leg. A horizontal overflow leg is connected to the upflow leg and at least two return legs connect the overflow leg to the furnace. The separated material from the separator passes through the legs of the pressure seal valve and sometimes through a heat exchanger (if included) before reentering the furnace.

Abstract: A fluidized bed combustion system in which a partition is disposed in an enclosure to divide the enclosure into two furnace sections for receiving beds of combustible particulate material. Air is introduced into each bed in quantities sufficient to fluidize the material and insufficient to completely combust said material, and additional air is introduced through said partition and into said sections in quantities sufficient to completely combust said material. An equalization port is provided through the partition for equalizing the pressure between the furnace sections.

Abstract: A method and apparatus for introducing a liquid or gaseous treatment medium into a flue gas stream wherein a total adjustment value for controlling the amount of active substance in the treatment medium is generated by an actual value measurement of a flue gas component and a comparison with a set value, and the treatment medium is injected through a plurality of nozzles into the flue gas stream flowing through a flow chamber. The flow chamber is divided into a three-dimensional matrix of partial flow chambers, each of which comprises a nozzle and measuring devices for detecting the temperature and flow speed of the flue gas stream in the partial flow chambers. The active substance is injected with a constant volume flow of treatment medium in an amount determined by calculation of an individual adjustment value of active substance for each nozzle. The total of the individual partial adjustment values does not exceed the total adjustment value of the active substance.

Abstract: A method of and apparatus for detecting an abnormality of a fluidized bed boiler is characterized in that an abnormality of the fluidized bed boiler is detected on the basis of a physical quantity related to a condition change of a gas existing in a space defined by a pressure vessel and the fluidized bed boiler accommodated within the pressure vessel.

Abstract: A method of treating solid residue resulting from combustion of a sulfur-containing fuel in the hearth of a boiler having a circulating fluidized bed, in which method limestone is inserted into the hearth so as to make it possible to absorb the resulting sulfur dioxide in the form of calcium sulfate CaSO.sub.4, the method further including the following steps:1) prior to being inserted into the hearth, the fuel is ground down to less than 100 microns;2) prior to being inserted into the hearth, the limestone is ground down to a grain-size centered in the range 100 microns to 150 microns, with a maximum of 1 mm;3) at the base of the hearth, the combustion residue is collected, which residue includes lime and calcium sulfate resulting from taking up the sulfur dioxide SO.sub.2 evolved by the combustion, and the residue is subjected to heat treatment in a reactor, in which both solid matter based on lime CaO, and also a gaseous mixture containing, in particular, sulfur dioxide SO.sub.

Abstract: A method for enhancing the minimization of NO.sub.x control in a circulating fluid bed steam generator into which there is injected fuel, fluidizing air, a lower level of combustion air and an upper level of combustion air. The fuel is injected at a first location, the fluidizing air is injected at a second location, the lower level of combustion air is injected at a third location and the upper level of combustion air is injected at a fourth location. In order to enhance the minimization of NO.sub.x control within a circulating fluid bed steam generator the lower level combustion air as well as the upper level combustion air are each biased in the horizontal plane as well as the vertical plane so as to thereby control the lower level combustion air flow and the upper level combustion air flow such that local stoichiometries within the circulating fluid bed steam generator are maintained within a range of 70% stoichiometry to 90% stoichiometry.

Abstract: The invention concerns a method and a device in the cooling of the circulating material in a fluidized-bed boiler. In the method the fuel (A) is introduced into the circulating-powder combustion chamber (10) of the fluidized-bed boiler into the lower part of the circulating-powder combustion chamber (10) and an inert circulating material, which contains a proportion of unburned powdered fuel (A), is circulated from the top part of the circulating-powder combustion chamber (10) to the lower part of the circulating-powder combustion chamber (10). The flue gases are passed in the method from the powder separator (13) along the duct (15) into the exhaust-gas boiler (16), through whose heat exchanger (16a) thermal energy of the flue gases is transferred further to other useful use.

Abstract: In a fluidized bed reactor system having a gas cooler, with cooling surfaces, downstream of a first cyclone separator, the cooling surfaces are cleaned by introducing sufficient concentration of bed particles into the gas during, or just prior to, cooling, so that the particles mechanically dislodge deposits from, and thereby clean, the cooling surfaces. The particles are then removed downstream of the cooler by a second separator, and the bed particles separated by the second separator may be returned to the fluidized bed reactor at or just before the cooler to again be used to effect cooling. Cleaning may be practiced in spaced time intervals only (e.g. periodically or intermittently), or continuously.

Abstract: Apparatuses for treating gas streams containing variations in VOC concentration whereby the VOC's are destroyed in a combination non-catalytic/catalytic oxidation system are disclosed. A non-catalytic destruction matrix composed of inert ceramic materials that enhance process mixing and provide thermal inertia for process stability is used when VOC concentrations are high and a catalytic oxidizer is principally used when VOC concentrations are low. The exhaust from the non-catalytic destruction matrix is passed through the catalytic oxidizer to maintain proper catalytic oxidizer operating temperatures. Supplemental fuel and air are added as appropriate upstream or downstream of the non-catalytic oxidizer to maintain proper heat values in each portion of the system.

Abstract: A method for maintaining a nominal working temperature of flue gases during operation of a PFBC power plant having a pressure vessel with a combustor enclosed therein for combustion of a fuel in a fluidized bed, a gas turbine for receiving flue gases formed during the combustion in the combustor, a compressor driven by the gas turbine for compression of air which is utilized as combustion air during the combustion in the combustor, and a steam turbine driven by steam generated in tube bundles in the bed, includes the steps of burning a complementary fuel in the flue gases generated during the combustion in the fluidized bed downstream of the tube bundle for increasing the flue gas temperature to a nominal level for the process and using oxygen residues in the flue gas as oxidizing agents during combustion of the complementary fuel.

Abstract: This invention related to aprocessing device such as a calciner or the like. The processing vessel is vertical with concentric cylindrical inner and outer walls, closely spaced and heated for rapid thermal processing, with strong boiling, evaporating, fluidizing and gasifying feed. This vigorous action is helping the steady gravitational movement of feed through the vessel. A top inlet for feed and a bottom outlet for residue are provided. Means for preventing air infiltration and means for controlling flow and keeping vessel filled during processing are provided. Any number of outlets for steam, boiling hot water, fluidized and gasified material at various heights of the vessel. Some material require addition of catalysts to bring about a chemical change and reduction in a pyrolitic process.

Abstract: A control system for a fuel-fired furnace and more specifically the control of the stoichiometric ratio of the combustion process occurring within the furnace of a steam generating power plant. The control system, when so employed, is capable of regulating the distribution of air flow to the combustion process such that the formation of oxides of nitrogen are maintained at acceptable levels. The control system includes in general a stoichiometric subsystem that determines the mass flow rate of air required to maintain the stoichiometric ratio within the combustion process; an override protection subsystem which ensures control precedence of the windbox-to-furnace pressure differential over the stoichiometry subsystem; and an overfire air subsystem that acts to apportion air flow amongst the various levels of overfire air within the boiler.

Abstract: Method and apparatus for using biofuel or waste material or both for energy production. The biofuel or the waste material is gasified in a fluidized bed gasifier (10), preferably a circulating fluidized bed gasifier. The gas produced in the gasifier is introduced into a boiler (12) equipped with fossil fuel burners (28, 28'28"), typically burners for pulverized coal. The gas is introduced at a level above the burners. Ash from the boiler may be used to form the bed of the gasifier. For control of NO.sub.x, the gas is burned in the upper part of the boiler at a low temperature level of 800.degree.-1050.degree. C. (1472.degree.-1922.degree. F.), preferably 850.degree.-900.degree. C. (1562.degree.-1652.degree. F.), and with a small excess air content of about 5-10 percent. In a second embodiment, the raw gas may be cleaned of harmful or noxious components, and cooled if desired, between the gasifier and the boiler in an additional circulating fluidized bed reactor (152) having a bed of coal ash.

Abstract: An electrical power generation plant has a gas turbine subsystem free of a compressor. A compressor subsystem remote from the gas turbine subsystem has an inlet receiving air and an outlet furnishing compressed air. A compressed air line interlinks the outlets and gas turbine subsystem. An aspect or the invention includes combusting sufficient fuel having sulphur content with sufficient limestone to establish a ratio of Ca/S greater than 3.4.

Abstract: A combustion method and apparatus in which combustible matter, e.g., waste matter, coal, etc., is gasified to produce a combustible gas containing a sufficiently large amount of combustible component to melt ash by its own heat. A fluidized-bed furnace has an approximately circular horizontal cross-sectional configuration. A moving bed, in which a fluidized medium settles and diffuses, is formed in a central portion of the furnace, and a fluidized bed, in which the fluidized medium is actively fluidized, is formed in a peripheral portion in the furnace. The fluidized medium is turned over to the upper part of the moving bed from the upper part of the fluidized bed, thus circulating through the two beds. Combustible matter is cast into the upper part of the moving bed and gasified to form a combustible gas while circulating, together with the fluidized medium.

Abstract: Method and apparatus for providing a gas seal in a CFB reactor, which is provided with a vertical, slot-shaped return duct (16), and for regulating the flow of circulating mass therein. The gas seal (22) is formed by arranging barrier means (22, 24, 26) on two different levels in the regulation zone of the return duct to slow down the flow of the circulating mass through the regulation zone. The flow of the circulating mass through the regulation zone is regulated by injecting fluidizing gas (56, 58, 60) into the regulation zone.

Abstract: The present invention relates to a combined cycle power plant comprising a air compressor providing pressurized air at pressure greater than 2 bar; a gas turbine means for driving the gas compressor means; a pressure vessel, circular in cross-section, connected to said air compressor and being capable of withstanding pressures greater than 2 bar; a pressurized circulating fluidized bed reactor enclosed by the pressure vessel, the circulating fluidized bed reactor having a reactor chamber, including substantially planar steam generation tube walls having a bottom section; means for leading hot combustion gases away from said reactor; one or more non-circular centrifugal separator(s) disposed within said pressure vessel being adapted to the reactor chamber and internal pressure vessel geometry for receiving and purifying hot combustion gases, having a gas outlet leading from said separator out of said pressure vessel; said centrifugal separator comprising a vertical vortex chamber having distinctly planar steam

Abstract: A method and apparatus for treating hot process gases produced in high temperature processes in a circulating fluidized bed reactor. The reactor (10) includes a mixing chamber (12), a particle separator (16) and a return duct (18) for returning the circulating mass from the particle separator to the mixing chamber. The return opening (24) of the return duct is so arranged that the flow of solids entering the mixing chamber via the opening is directed substantially downwardly. The inlet (22) for hot process gas is so arranged as to allow the hot process gas to flow into the mixing chamber as a substantially upwardly directed solids flow so that the solids flow comes into contact with the gas flow.

Abstract: A fluidized bed system which includes a housing and a floor comprising a plurality of generally parallel tubes joined by fins intermediate adjacent tubes. A plurality of nozzle assemblies extend generally vertically in mutually parallel relationship from the floor. Each of the nozzle assemblies includes a generally cylindrical body having a centerline disposed in generally perpendicular relationship to the floor and each of the bodies includes a plurality of heads extending generally radially therefrom at an axial extremity thereof remote from the floor. In some embodiments of the invention each of the heads are uniformly spaced around the circumferential extent of each of the bodies and each of the heads is generally cylindrical and has a centerline. Each of the centerlines of the heads may be disposed at an angle with respect to a horizontal plane and the angle may be approximately twenty degrees.

Abstract: A system and method of operating a pressurized fluidized bed system in which a bed of particulate material is fluidized by distributing air through the bed. A mixture of flue gases and entrained, relatively fine, material from the reactor is passed to a separator and the material is separated from the gases and passed to an external heat exchanger. A portion of the material is cooled in the heat exchanger and it, along with the remaining portion of material, is recycled to the reactor.

Abstract: In order to maintain the flue gas temperature from a steam generator up to the temperature required for a NO.sub.x catalytic reactor during low load operations, the flow of feedwater through the steam generator economizer is controlled to control the degree to which the flue gas is cooled as it passes over the economizer heat exchange surface. More specifically, an economizer bypass line is provided and the flow of feedwater during low load operations through the bypass line and the economizer is regulated to maintain a desired flue gas temperature to the catalytic reactor. As the flue gas temperature changes with load, the flow through the economizer and bypass line is modulated to maintain a proper temperature. At full or near full load, the bypass line is fully closed.

Abstract: The present invention relates to a fastening system for fastening a through pipe to a hearth wall, the pipe opening into a box. The fastening system comprises external pipe-securing means for securing the pipe to said screen, and an internal metal guide tube fitted over said pipe and having one of its ends interposed between said pipe and the orifice through which said pipe passes, its other end being externally threaded. The guide tube carries a rigid washer which is disposed so as to abut against the inside face of the inside layer, and against which a wall of the box is mounted, which wall is provided with an orifice that is larger than the cross-section of the guide tube, a sealing device being clamped against the wall of the box by a nut screwed onto the threaded end of the guide tube.

Abstract: A porous matrix, surface combustor-fluid heating apparatus comprising a combustion chamber, a porous stationary bed disposed within the combustion chamber, a porous bed heat exchanger for retaining the porous stationary bed within the combustion chamber, a fuel/oxidant inlet for introducing a fuel/oxidant mixture into the stationary porous bed, a distributor plate for distributing the fuel/oxidant mixture within the stationary porous bed proximate an inlet end of the combustion chamber, and a porous bed heat exchanger comprising at least one vertically oriented, fluid-cooled tube disposed in the stationary porous bed.

Abstract: Particles in a fluidized bed reactor (e.g. a circulating fluidized bed reactor) are discharged from the reactor chamber and then cooled (heat is recovered from them) in a processing chamber. This is accomplished in a particularly advantageous way by discharging the particles from the reactor chamber at a first level (e.g. through a non-mechanical seal or a classifying wall) into a lifting chamber. Upwardly flowing gas in the lifting chamber entrains the particles and lifts them into the processing chamber. After processing, the particles in the processing chamber are returned to the reactor chamber at level higher than the first level, at which point the pressure in the processing chamber is higher than the pressure in the reactor chamber. The particles may be classified in the lifting chamber by utilizing fluidizing gas to transport solid particles smaller than a predetermined size to the processing chamber while discharging larger particles from the bottom of the lifting chamber.

Abstract: A fluidized bed combustion system and method in which a recycle heat exchanger is disposed integrally with the furnace of a fluidized bed combustor. The recycle heat exchanger includes a plurality of stacked sections for receiving the recycled solids and are arranged in such a manner that the recycled solids are introduced into an upper level of the sections and pass through these sections to a lower level of sections before returning to the furnace. A portion of the stacked sections contain heat exchange surfaces for removing heat from the solids therein while another portion does not. The solids in the various sections are selectively fluidized to control the flow of the solids through the sections to control the temperature of the solids accordingly.

Abstract: A fluidized bed reactor system includes a reaction chamber comprising a circulating (fast) fluidized bed, with a first grid for the introduction of fluidizing gas, and a bubbling (slow) fluidized bed having a second grid for introduction of fluidizing gas. The second grid is mounted below the first grid. First and second interconnections are provided between the circulating and bubbling beds. Particles flow from the circulating bed through the first interconnection to the bubbling bed, and vice versa for the second connection. The interconnections are positioned with respect to each other so that the pressure and density conditions within the beds are the sole mechanisms that provide the driving force to control the flow of particles from the circulating bed to the bubbling bed.

Abstract: A circulating fluidized bed reactor has substantially vertical walls with cooling elements, defining the interior of the reactor chamber, and a device for introducing fluidization gas at the bottom of the fluidized bed reactor. Particulate material is introduced into the reactor. A separator separates particulate material from the exhaust gases, the separator being in connection with the reactor chamber. A return duct is connected to the separator. A bubbling fluidized bed is adjacent the reactor and provided with a heat exchanger for cooling particulate material, and side walls, rear and front walls having cooling elements in fluid communication with the cooling elements of the reactor chamber; and a discharge channel with a separate fluidizing gas source for discharging particles from the bottom of the bubbling bed to adjacent the top of the bubbling bed in the reactor chamber.

Abstract: A burner with a housing enclosing a combustion chamber and with an inlet for a gas/air fuel mixture and an outlet for combustion gas is disclosed. The combustion chamber is filled with a porous material whose porosity varies along the combustion chamber in such a way that the pore size increases in the direction of flow of the gas/air mixture so that a critical Peclet number for the pore size and accordingly for flame development results at a boundary surface or in a determined zone of the porous material, above which number a flame can develop and below which number the flame development is suppressed.

Abstract: A pressurized internal circulating fluidized-bed boiler is incorporated in a combined-cycle electric generating system in which a fuel such as coal, petro coke or the like is combusted in a pressurized fluidized bed and an exhaust gas produced by the combusted fuel is introduced into a gas turbine. The pressurized internal circulating fluidized-bed boiler includes a pressure vessel, a combustor disposed in the pressure vessel and a main fluidized bed combustion chamber provided with an air diffusion device. A thermal energy recovery chamber is partitioned from the main combustion chamber by an inclined partition wall. A fluidized medium flows into and out of the main combustion chamber and the thermal energy recovery chamber. A free board is provided integrally above the main combustion chamber and the thermal energy recovery chamber so that combustion gas from the main combustion chamber and the thermal energy recovery chamber is mixed in the free board.

Abstract: Apparatus for cleaning high temperature, high pressure gases includes a pressure vessel, and a filtration unit within the pressure vessel. The filtration unit is adapted to communicate with a fluidized bed reactor gas outlet, and includes at least one dirty gas chamber housing a plurality of porous, ceramic filter tubes, and at least one clean gas chamber for receiving clean gas from the ceramic filter tubes. The dirty gas chamber includes a particle outlet for removing particles separated from the gas by the filter tubes. The porous ceramic filter tubes are horizontally oriented within the filtration unit or housing and mounted within water cooled walls of the housing. The fluidized bed reactor and associated cyclone separator may be located within the pressure vessel with the filtration unit, or located outside the pressure vessel and in communication with the filtration unit inside the pressure vessel.

Abstract: A method and apparatus for cooling hot gas in a reactor in which the lower section of the reactor is provided with an inlet for hot gas and a chamber encompassing a bubbling fluidized bed. A central section of the reactor is provided with a riser, and the upper section with a gas outlet, and the reactor has heat transfer surfaces for recovering heat from solid particles. The riser is defined by vertical walls which are disposed above the bubbling fluidized bed so that they divide the fluidized bed into concentric outer and inner parts. From the inner part of the fluidized bed solid particles are supplied to the hot inlet gas for cooling thereof. The gas containing solid particles is conveyed through the riser into the upper section of the reactor, where solid particles are separated from the gas in a particle separator and returned to the fluidized bed into the outer part thereof.

Abstract: In a combustion device, a boiler is provided with a water tube nest in which combustion, flame holding, fuel-air mixing, and heat absorption are carried out by each water tube in a tube nest. The arrangement of this combustion device enables elimination of the conventional burner and furnace. Fuel supply devices are provided upstream of the water tube nest to supply fuel or a fuel-air mixture. One or several combustion catalysts are provided across the gas flow direction in the boiler to promote combustion. In one arrangement, the fuel supply devices are fuel supply tubes, and fuel or fuel and air are supplied to the fuel supply tubes and spouted from fuel injection nozzles thereof. The fuel supply tubes and water tubes are arranged such that the row of fuel supply tubes is spaced upstream from the first water tube row, such that L.gtoreq.3D where L is the pitch between the fuel supply tube row and the first water tube row, and D is the diameter of the water tubes. Also, P .gtoreq.

Abstract: A fluidized bed reactor system, including a reactor chamber defined by a wall structure formed by a plurality of tubes through which a heat transfer medium circulates, is constructed so as to provide numerous advantages over conventional constructions. A fast fluidized bed of solid material is established in the reactor chamber. A solid material processing chamber is disposed adjacent the reactor chamber on the outer side of a wall structure defining the reactor chamber, e.g. for recovering heat from the solid material. The processing chamber shares a common wall portion with the reactor chamber and a slow fluidized bed of solid material is provided in the processing chamber. Particle passage openings are provided in the common wall. Particles from the processing chamber are recirculated to the reactor chamber after treatment (typically cooling).

Abstract: In a pressurized fluidized bed boiler, furnace means is divided into at least two separate furnaces: a furnace with an evaporator and a superheater disposed therethrough, and a furnace with the superheater and a reheater disposed therethrough. The furnaces are accommodated in separate pressure vessels, respectively. Air is supplied into the pressure vessels through air pipes connected to the pressure vessels, where it is used for pressurizing the pressure vessels, and then supplied into the furnaces through their lower portions, where it is used as a combustion air. An oxygen concentration meter is mounted in an exhaust gas pipe in an outlet of the furnace, and an air flow rate adjusting valve 3 is mounted outside each of the pressure vessels.

Abstract: A circulating fluidized bed boiler comprises a fluidized bed combustion chamber, a recirculating system for recirculating fluidized solids through the combustion chamber, and a plurality of tubes for withstanding supercritical pressure are disposed around the walls of the combustion chamber for circulating cooling fluid between an inlet header at the bottom of the chamber and an outlet chamber at the top of the combustion chamber. A water steam separator directs steam to a superheater and is bypassed during normal operation.

Abstract: A fluidized bed combustion system in which a fluidized bed of particulate fuel material is established in a furnace. A duct is formed in the upper portion of said furnace for passing a mixture of flue gases and entrained particulate fuel material to a separator located adjacent the furnace outlet. A heat exchanger is also disposed in the upper portion of the furnace at approximately the same height as the duct so that a portion of the mixture passes over the heat exchanger and then exits via the duct and another portion of the mixture exits directly through the duct.

Abstract: A method of reducing the nitrogen oxide level in the flue gases issuing from combustion units by introduction of reducing agents into contact with gases containing nitrogen oxides in first and second reducing stages, is provided. The first reducing stage is a non-catalytic stage (e.g. at temperatures over 800.degree. C.), while the second stage is a catalytic stage (e.g. at temperatures of about 300.degree.-400.degree. C.). A steam generation boiler with improved nitrogen reduction facilities is also provided. The amount of nitrogen oxides in the hot gases is reduced in the combination of the first and second reducing stages while producing steam in a steam generation boiler system, thus resulting in gases essentially free from nitrogen oxides while eliminating the possibility of NH.sub.3 (or other reducing agent) slip in the exhausted flue gases. Heat transfers in a convection section as used to establish stabilized temperature conditions for catalytic reduction.

Abstract: A fluidized bed combustion system and method in which a recycle heat exchanger is located adjacent the furnace section of the recycle heat exchanger. Heat exchange surfaces are provided in a compartment of the recycle 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. The flow of solids between compartments is selectively controlled and an L-valve connects one of the compartments to the furnace section. Air is passed into the L-valve to promote the flow of the separated materials from the latter compartment to the furnace. The flow rate of the air is modulated to vary the duty of the recycle heat exchanger.

Abstract: A system and method are disclosed for lowering NO.sub.x levels in flue gases of a fluidized bed reactor using selective non-catalytic reduction. A reactor is connected to a separator by a duct, and a reactant is introduced into the duct for decreasing NO.sub.x levels in the flue gases passing from the reactor, through the duct, and into the separator. The reactant, such as ammonia or urea, is selectively injected into a gaseous-rich region of the duct, near an upper, inner portion of the duct, so that a high degree of mixing of the reactant with flue gases is achieved while maintaining a low degree of mixing of the reactant with the particulate materials. The point of injection of the reactant into the duct is also at a location nearer to the reactor than to the separator to provide for increased residence time. In this manner, the reactant is used efficiently while obtaining the desired lowering of NO.sub.x levels in the flue gases.

Abstract: The invention relates to a boiler for the production of steam, the boiler having a maximum capacity of 100 ton/hr or more and comprising a furnace having a substantially constant rectangular cross-section and a back pass with a substantially constant rectangular cross-section. The furnace and the back pass are mounted close to each other and means are provided for superheating the steam. The steam superheating means are positioned within the back pass, so that no superheater is positioned within the furnace.

Abstract: A pressurized fluidized bed reactor is provided utilizing a centrifugal separator having a gas space that is distinctly non-circular, preferably having a circularity of greater than or equal to 1.15. Most desirably the cyclone has a quadrate (e.g. square) cross-section, and is disposed inside of the pressure vessel along with the reactor chamber containing the fluidized bed. A number of ceramic candle or honeycomb filters may be provided connected to the gas outlet from the cyclone separator, within the pressure vessel, to filter the gas. This construction provides a minimized diameter of the pressure vessel because the reactor chamber with square cyclones is more compact than if conventional circular cross-section cyclones are employed. Also a second pressure vessel is not needed for the candle or honeycomb filters since there is sufficient room within the pressure vessel to accommodate them.

Abstract: A fluidized bed combustion apparatus having an upright combustion chamber with a lower end at which a fluidized bed is formed and combustion takes place. First and second upright partitions are provided in the combustion chamber to divide the combustion chamber into a plurality of sections. The first partition divides the combustion chamber into first and second sections which are joined together by a turning space above an upper end of the first partition and the second partition is hollow and has an open, upper end in communication with the turning space to receive a portion of the combustion products therein. The lower end of the second partition is open to supply the combustion products to the fluidized bed.

Abstract: Hot gases from a pressurized fluidized bed reactor system are purified. Under superatmospheric pressure conditions hot exhaust gases are passed through a particle separator, forming a flitrate cake on the surface of the separator, and a reducing agent--such as an NO.sub.x reducing agent (like ammonia), is introduced into the exhaust gases just prior to or just after particle separation. The retention time of the introduced reducing agent is enhanced by providing a low gas velocity (e.g. about 1-20 cm/s) during passage of the gas through the filtrate cake while at superatmospheric pressure. Separation takes place within a distinct pressure vessel the interior of which is at a pressure of about 2-100 bar, and-introduction of reducing agent can take place at multiple locations (one associated with each filter element in the pressure vessel), or at one or more locations just prior to passage of clean gas out of the pressure vessel (typically passed to a turbine).

Abstract: An apparatus and method of operating a fluidized bed reactor for combusting refuse derived fuel is disclosed. The reactor includes a fluidized furnace section 30 and stripper/cooler section 80. A downwardly sloping grid 28 extends across the furnace section 30 and stripper/cooler section 80 to a drain 78 in the stripper/cooler section 80, and directional nozzles 38 disposed in the grid fluidize the beds in the furnace section 30 and stripper/cooler section 80 and forcibly convey relatively large particulate material across the grid 28, through the furnace section 30 and stripper/cooler section 80, and to the drain 78 for disposal. A refractory layer 36 is provided along the grid 28 surface to reduce the height of the nozzles 38 within the furnace section 30, thereby helping to prevent relatively large particulate material from becoming entangled with or stuck to the nozzles 38.

Abstract: A combined cycle power generation system and method in which a fluidized bed reactor is incorporated in a combined cycle system to recover heat from the hot exhaust gases from the gas turbine and to drive a series of steam turbines. Additional heat is provided by a combustor receiving fuel gas from a fuel gas generator and the hot gases thus generated are used to drive the gas turbine. The hot exhaust gases from the gas turbine are used as the primary fluidizing gas for the circulating fluidized bed reactor. The reactor is used to recover heat from the hot exhaust gases from the gas turbine and to generate steam to power a series of steam turbines. Additional heat is recovered, and pollutants are removed from flue gases by a condensing lower economizer.

Abstract: An apparatus for separating solids from a solids and gas flow in a combustor having a fluid circulating system uses a plurality of separators adjacently positioned and horizontally spaced in a path of a solids and gas flow. Each separator includes four tubes. A membrane connected between selected tubes creates a concave-shaped configuration that will capture oncoming solids particles entrained within the flue gas. In one embodiment, fluid from the fluid circulating system flows serially from an inlet into a first leading tube of a first separator through the tubes in each separator in a given row and finally through the second leading vertical tube of a last separator in that row to an outlet and back to the fluid circulating system. Connector tubes communicate with the first leading tube and the first rear tube, the first rear tube and the second rear tube, and the second rear tube and the second leading tube.

Abstract: A fluidized bed reactor in which a plurality of air bars are supported by a plurality of tubes in an upright enclosure. The air bars support a bed of particulate material and discharge air into the bed to fluidize the material. A cooling fluid is passed through the tubes to transfer heat from the air bars.

Abstract: The present publication discloses a method and an apparatus for drying the fuel used for firing a fluidized-bed boiler (1). The hot, inert solids of the fluidized bed are circulated by a regulated rate from the furnace (2) to a simple dryer (11) incorporated into the fuel feed line (7) to the boiler (1), whereby the fuel is dried and steam is generated. By virtue of controlled bed solids recirculation, a constant temperature of the dryer (11) can be maintained, thus permitting the omission of all heat transfer surfaces from the dryer (11). The nearly clean steam released from the drying process is routed from the dryer (11) to useful applications. (FIG.

Abstract: A process is set forth for directly controlling the quantity and particle size distribution of the solid inventory inside a circulating fluidized bed combustor. A portion of the bed ash is withdrawn from the combustor as bottom ash. The particle size distribution of the stream is adjusted, such as by a hammermill, to a specified distribution. Finally, a portion of the adjusted ash is re-injected into the combustor. The process may be facilitated by size classifying the bottom ash prior to size reduction.