Abstract: An apparatus and method to permit the burning of high and varying moisture content fuels without requiring supplemental fuel (oil or gas) firing. The invention provides in-situ drying of the high and varying moisture content fuels by modulating the temperature of the combustion air entering the furnace (11) of the vapor generator (10). The variable flow paths taken by the air and flue gas are functions of the moisture content of the fuel being fired. The flue gas may be selectively by-passed around an economizer (20) for direct introduction into a first air heater (30). The gas is then passed through a precipitator (34) and a second air heater (40). Combustion air is passed through the second air heater (40) and may be then apportioned between the first air heater (30) and a by-pass (60) around the air heater (40) before introduction into the furnace (11).

Abstract: A filter house (12) employing a selective catalytic reduction process for removing NO.sub.x emissions from a flue gas stream while simultaneously filtering out and collecting entrained particulate matter from the stream. Accordingly, the filter house (12) includes flue gas inlet and outlet passages (18, 30) and a plurality of porous filter bags. The bags are treated with a suitable catalyst to facilitate the selective catalytic reduction process.

Abstract: An instrumentation installation tool (30) for weldably attaching strain gages (20) or other instrumentation to the interior of a steam generator tube (42). The exterior surface of the section (32) is formed with four longitudinal grooves (32A, 36B, 36C and 38). A welding slot (44) is situated in one of the grooves (38). A ramp (46), oriented within the section (32) is in close proximity to the slot (44). Additionally, an elongated multitipped electrode (80) is slidably and coaxially disposed within the section (32).

Abstract: An underfeed fuel feeder for introducing granular material into a fluidized bed. One embodiment introduces material into the bed through a perforated cavity-shaped feed nozzle disposed beneath an air distribution plate. A second embodiment introduces material through a T-shaped nozzle disposed above the plate. A housing protects the nozzle. A third embodiment depicts the nozzle-housing combination in a fluidized bed boiler employing water cooled floors.

Abstract: An apparatus and method for removing very finely divided alkali fumes and other particulate material from a coal-gasifier make-gas comprising the introduction of char granules into the constricted passage of a venturi-shaped gas duct to adsorb the very fine particulate from the make-gas flowing therethrough, and centrifugally separating the fume-laden char granules from the make-gas.

Abstract: A heat exchanger including a pressure vessel and a plurality of heat exchanger tubes extending within the vessel. A tube shroud forms an annular passage between the tubes and the pressure vessel wall. A partition wall, comprising a plurality of openings normally closed by closure means, divides the passage into a fluid inlet compartment and a fluid outlet compartment. In the event the fluid pressure differential between the inlet and outlet compartments attains a predetermined value, at least some of the closure means will open to reduce the pressure differential below the predetermined value. In one embodiment of the invention, the closure means comprise flap valves. In an alternate embodiment of the invention, rupture discs are utilized as closure means.

Abstract: A coal conveyor capable of transporting pulverized coal to a higher pressure zone. The conveyor comprising an upright pressure vessel and a feed pipe extending into and between two endless conveyor belts located within the vessel which mesh during their descent to form a first and second pressure seal before the discharge of the coal into the higher pressure zone.

Abstract: An explosive activated tube plug for effecting a mechanical seal within a tube is disclosed. The plug includes an internally tapered expansion sleeve, a frusto-conical piston disposed within the sleeve and an extension member to expedite plug placement. By remotely detonating an explosive disposed within the plug, the piston is driven forward to expand the sleeve against the surrounding tube surface. By modifying the physical structure of the plug, the energy-displacement relationship between the piston and sleeve may be selectively controlled.

Abstract: A blowdown apparatus for effectuating the removal of contaminants entrained within the boiler water of a vapor generator. The apparatus comprising a perforated blowdown pipe vertically oriented within the generator. In addition, a blowdown and drain connection is provided near the lower end of the pipe so that contaminant bearing blowdown fluid may be expelled from the generator.

Abstract: An asymmetrical welding ring for facilitating the end to end welding of tubes having unequal inside diameters. The welding ring is provided with an arcuate inner periphery and an irregular outer periphery divided into three distinct frustoconical surfaces.