Abstract: A process chamber is placed in connection with a fluidized bed reactor for utilizing internal or external circulation of solid material or both in heat transfer purposes. Said process chamber is located inside the furnace of a circulating fluidized bed reactor adjacent to at least one of the furnace walls. The interior of said process chamber is provided with heat exchanger means for heat transfer from the solid material to heat transfer medium inside the heat exchanger means. The process chamber comprises a top closed barrier wall forming the roof of the process chamber, wherein the inlet of the solid material into the process chamber is arranged to the lower part of the wall of the process chamber and the outlet of the solid material out of the process chamber is arranged to the upper part of the wall of the process chamber.

Abstract: A process chamber is placed in connection with a circulating fluidized bed reactor for utilizing internal or external circulation of solid material or both in heat transfer purposes. Said process chamber is located inside the furnace of the circulating fluidized bed reactor adjacent to at least one of the furnace walls. The interior of said process chamber is provided with heat exchanger means for heat transfer from the solid material to heat transfer medium inside the heat exchanger means. The process chamber comprises a top closed barrier wall forming the roof of the process chamber, wherein the inlet of the solid material into the process chamber is arranged to the lower part of the wall of the process chamber and the outlet of the solid material out of the process chamber is arranged to the upper part of the wall of the process chamber.

Abstract: A method and system for controlling reheater steam temperature is disclosed. The method can be carried out by selectively adjusting the flow of superheated steam into a superheater positioned between two reheater sections in the convection pass of a carbonaceous fuel boiler system.

Abstract: A method and system for recycling a sulfur sorbent present in the combustion residue of a circulating, fluidized bed, fossil-fuel combustor is disclosed. The method can comprise the steps of, adding water to the combustion residue, classifying the combustion residue into a fuel ash portion and a hydrated sorbent portion, and returning the hydrated sorbent portion to the circulating, fluidized bed, fossil-fuel combustor.

Abstract: A biased air distribution grid is used to promote solids entrainment and dense bed internal mixing for the bed material of a fluidized bed reactor. The air distribution grid distributes air at a high velocity zone having a velocity ranging from 11 to 50 feet per second and a low velocity zone having a velocity ranging from 3 to 10 feet per second. The high velocity zone and the low velocity zone provide an improved lateral mixing for the reactor.

Abstract: A cyclone separator for a solids-laden process gas from a fluidized bed boiler or reactor also provides a pressure seal and heat exchanger surfaces for the reactor or boiler. The cyclone includes a cylindrical main housing with a longitudinal axis. The housing is made of membrane wall construction. A portion of the tubes are bent outwardly to form an inlet which communicates with the main housing for receiving the solids-laden process gas from the boiler or reactor. Solids are separated from the solids-laden process gas as they swirl together in the main housing of the cyclone separator. A partition wall is disposed at the lower section of the main housing around the longitudinal axis for defining an outer chamber and an inner chamber adjacent the outer chamber. Gas is provided to the outer and inner chambers for creating fluidized beds of the solids in the outer and inner chambers. Solids are passed from the inner chamber to the outer chamber through an underflow port in the partition wall.

Abstract: A cyclone separator for a solids-laden process gas from a reactor also provides a pressure seal for the reactor. The cyclone includes a main housing with a longitudinal axis. The housing is made of a membrane wall construction having a plurality of tubes arranged around the axis and encased within membrane wall panels. A portion of the tubes are bent outwardly to form an inlet which communicates with the main housing for receiving the solids-laden process gas from the boiler. Solids are separated from the solids-laden process gas as they swirl together in the main housing of the cyclone separator. A partition wall is disposed at the lower section of the main housing around the longitudinal axis for defining an outer chamber and an inner chamber adjacent to the outer chamber. Gas is provided to the outer and inner chambers for creating fluidized beds of the solids in the outer and inner chambers. Solids are passed from the inner chamber to the outer chamber through an underflow port in the partition wall.

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: A fluidized bed combustion system and method in which a recycle heat exchanger is located adjacent the furnace section of the combustion system. A mixture of flue gases and entrained particulate materials 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 fluidized bed in the recycle heat exchanger. A first chamber and plurality of additional chambers are formed in the recycle heat exchanger. 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. The separated particulate material from the fluidized bed in the furnace section is introduced into one of the chambers and the chambers communicate to permit the material to flow between the chambers.

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: A fluidized bed reactor in which a recycle heat exchanger is located adjacent the furnace of the reactor with each enclosing a fluidized bed and sharing a common wall including a plurality of water tubes. A mixture of flue gases and entrained particulate materials from the fluidized bed in the furnace are separated and the flue gases are passed to a heat recovery area and the separated particulate material to the fluidized bed in the recycle heat exchanger. The bed materials in the fluidized bed in the recycle heat exchanger are passed to the fluidized bed in the furnace. Steam is generated, superheated and reheated in the heat exchange surfaces, including water wall tubes, in the furnace, the recycle heat exchanger, and the heat recovery area.

Abstract: A method of controlling the particle size distribution in a fluidized bed reactor in which a primary bed of particulate material having a varying size and including fuel is established. Air is introduced into the bed to fluidize the material and promote the combustion of the fuel. A portion of the particulate material is discharged from the bed and into a secondary bed. Air is introduced to the secondary bed at a velocity sufficient to fluidize the particulate material and entrain some of the finer portions of the particulate material. The air and the entrained finer material from the secondary bed are passed back to the primary bed and the velocity of the air introduced to the secondary bed is varied to vary the amount of the finer material that is entrained and thus control the size of the material in the primary bed.

Abstract: A method of operating a fluidized bed reactor in which a bed containing solid particulate material is fluidized by introducing air into the bed. A gas column is formed containing a mixture of the air, the gaseous products of combustion or gasification of the fuel in the bed and the particulate material entrained by the air and the gaseous products of combustion. The mixture is discharged from the vessel and the particulate material is separated from the mixture and returned to the bed. The entrainable particulate material is maintained in the bed and in the gas column in quantities sufficient to saturate the gas column. The temperature of the fluidized bed is controlled by varying the amount of air introduced into the bed.

Abstract: A fluidized bed steam generator and method of generating steam including a separate recycle bed in which a plurality of vertically stacked fluidized beds are disposed in a furnace enclosure and a heat recovery enclosure is defined adjacent the furnace enclosure for receiving the effluent gases from the fluidized beds. A fluidized bed is defined in the heat recovery enclosure and one or two separators are provided adjacent the heat recovery enclosure for receiving the effluent gases and separating the entrained solid particles therefrom. The separated solid particles are then injected into the fluidized bed in the heat recovery enclosure. Fresh fuel is supplied to the recycle bed and the material inventory and fluidizing velocity in the recycle bed is controlled.

Abstract: A system for the fluidized reinjection of fine particles (carryover) into a fluidized bed combustor. The carryover recirculation system includes a fluidized reinjection bed which is fluidized using clean gas from the induced draft fan outlet boosted by a small auxiliary fan. The fluidized fine particles can be reinjected into the fluidized combustor bed by either dense phase transport or by dilute phase transport.