Abstract: An apparatus and method of operating a steam generator tube bank are disclosed in which a water drum of a typical steam drum/water drum combination is replaced with a plurality of smaller readers to permit the use of rapping, or mechanical rappers, to clean the tubes extending between the steam drum and the headers. The steam generator tube bank of the present invention comprises a steam drum or collecting header, a plurality of headers extending below the steam drum, and a plurality of tubes extending between the steam drum and the headers and placing the steam drum and headers in fluid flow communication. The headers are sized to permit debris or deposits which accumulate on the tubes to be removed by rapping the headers, thereby inducing vibration of the headers and the tubes. The tubes are arranged in rows, and the headers are arranged to form rows of axially-aligned pairs of headers.

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: 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 fluidized bed combustion system and process is disclosed, in which full load stoichiometry is maintained at lower loads. The system and process includes an enclosure and a partition disposed in the enclosure to define a furnace section and an overfire air plenum section. A bed of combustible particulate material is formed in the furnace section and air is passed into the bed in quantities sufficient to fluidize the material and insufficient to completely combust the material. Overfire air is passed into the overfire air plenum, through control dampers in the partition and into the furnace section in quantities sufficient to completely combust the material.

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 steam generator and method for operating same in which a plurality of beds of combustible particulate material are established and air is introduced to each of the beds for fluidizing the beds. The flue gases and entrained fine particulate material from each bed are combined and the particulate material then separated from the flue gases externally of the beds and introduced back into one of the beds. Independent fluid circuits are established including some in heat exchange relation to the separate beds, for independently controlling the steam generation rate and the temperatures of the reheat steam, and the superheat steam.