Abstract: A method and apparatus for treating synthesized gas ("syngas") comprises introducing the syngas into a lower portion of a vessel. The syngas flows in the lower portion through a static regenerative hot gravel bed and into an upper portion of the vessel containing particulate material at a temperature less than that of the syngas in a manner so that the material reduces the temperature of the syngas and reacts with the syngas to abate pollutants therein, and the syngas entrains at least a portion of the material. The entrained material is then separated from the gas, cooled in a heat exchanger, and returned to the vessel, while the separated syngas is passed to downstream facilities.

Abstract: A steam generating system including an upright furnace section formed by a plurality of tubes, a portion of which have upper and lower tube ends and extend at an acute angle with respect to a horizontal plane, a portion of which extend vertically downwards from the lower tube ends, and a portion of which extend vertically upwards from the upper tube ends. Additional lower and upper vertical tubes are provided which are coplanar with, parallel to, and evenly distributed and interlaced among the tubes extending vertically from the respective lower and upper ends. Means is provided to pass fluid through the length of the furnace section to convert a portion of the fluid to steam or to heat the fluid, the fluid passing upwards first through the additional lower vertical tubes, then through the length of the angularly extending tubes including the vertical extensions thereof, and then through the additional upper vertical tubes.

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: 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: A rapping hammer system adapted for periodically rapping and cleaning tubes of a heat exchanger unit to remove undesired deposits from outside the tubes. A plurality of rapping hammers are each pivotably attached to a radial arm extending outwardly from and spaced apart along a rotatable shaft. A spring device is attached to each radial arm and arranged to contact the rapping hammer with sufficient force so as to substantially restrain repeated striking movements of the rapping hammer against an impact stem of the heat exchange unit following an initial impact of the hammer. A method is also disclosed for operating the rapping hammer system for periodically rapping and cleaning the outside surface of heat exchanger tubes such as boiler tubes of accumulated ash and soot deposits.

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 and method of operating same in which a bed of particulate material including fuel is formed in a furnace section. A stripper-cooler is located adjacent the furnace section for receiving particulate material from the furnace section. The particulate material is selectively passed to the stripper-cooler and cooled before being discharged from the stripper-cooler.

Abstract: A method for reducing gaseous emission of halogen compounds in a fluidized bed reactor in which the fine particles entrained in flue gases are used to form a temporary layer of particles on the baghouse filter to absorb halogen gases.

Abstract: A system and method for resisting thermoacoustic oscillations in systems comprised of hot and cold components is disclosed. More particularly, a combined cycle power generation system 32 having a gas turbine 40, a gas turbine discharge duct 34, and a gas turbine recuperator 36 and 38 is disclosed. The system 32 is designed to resist severe thermoacoustic oscillations over its entire load range by providing for an asymmetrical arrangement of the hot section L-l, including the gas discharge duct 34 and the plenum 36 of the recuperator, and the cold section L-l, including the heat exchange tubes 38 of the recuperator. Also disclosed is a steam generation system 42 having a plenum 46, a burner 48, and a furnace 44. The steam generation system 42 is also designed to resist severe thermoacoustic oscillations by providing for an appropriate burner length L and by providing for an asymmetrical arrangement of a hot burner section L-l and a cold burner section l within the burner 48.

Abstract: An orbital type welding apparatus adapted for use in welding tubes into a tubesheet by an inert gas electric arc welding process. The welding apparatus includes a housing, a rotor rotatably mounted within the housing, and a pilot probe unit extending from the housing lower side. The pilot probe unit contains a plurality of resiliently-mounted convex projections such as balls, which are spaced apart both circumferentially and longitudinally with respect to the pilot probe unit. The balls are mounted in transverse openings in the pilot unit. The spring-loaded projections serve to center the pilot unit and welding apparatus more quickly and accurately within a tube being electric arc welded to a tubesheet. Alternatively, a pilot probe unit having a plurality of transverse grooves can be used for welding tubes which are essentially round.

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 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 method and apparatus for treating gas introduced into a vessel containing a particulate material at a temperature less than that of the gas in a manner so that said material reduces the temperature of the gas and the gas entrains at least a portion of the material. The entrained material is then separated from the gas and passed to a heat exchanger to cool the material while the separated gas is passed to a turbine to drive same. At least a portion of the exhaust gas from the turbine is passed to the heat exchanger in a manner to fluidize the material in the heat exchanger and the cooled separated material is returned back to the vessel.

Abstract: A mounting and linkage system for mounting an air or air-fuel discharge device for pivotal and axial movement relative to a furnace in a manner so that the device is isolated from the walls of the furnace. The system includes a linkage apparatus extending between the furnace walls and connected to the device for pivoting same.

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: 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: 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: A burner assembly in which an annular passage is provided for transporting an fuel/air mixture to a furnace inlet. A conical divider member is disposed within the annular passage for dividing the stream of fuel/air passing through the passage into two radially-spaced coaxial, passages. A plurality of angularly-spaced walls are disposed within one of said passages for dividing the latter passage into a plurality of segments for splitting up fuel/air stream so that, upon ignition of said fuel, a plurality of flame patterns are formed. Ribs are provided on one of the surfaces defining the other passage to concentrate the fuel portion of the mixture flowing through said latter passage to form an additional flame pattern which is surrounded by the above-mentioned plurality of flame patterns.

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.