Abstract: A method of vaporizing aqueous reducing agent for reducing NO.sub.x in flue gas in a combustion system. A heat exchanger is disposed in the flue gas path so that heat from the flue gas heats a heat transfer medium, preferably ambient air. The heated air is passed to a vaporizer vessel where it vaporizes an aqueous reducing agent, preferably aqueous ammonia. The vaporized ammonia is injected into the flue gas path where it is effective to reduce NO.sub.x. Some aspects of an automatic control system are disclosed.

Abstract: A fluidized bed system in which a plate is disposed in an enclosure and is adapted to support particulate material. A plurality of nozzles are supported by the plate for receiving air and directing the air through the plate and into the particulate material to fluidize same. Each of the nozzles includes a vertical tubular portion extending upwardly from the plate for receiving air from the air plenum, an angled tubular portion extending downwardly and outwardly from the vertical tubular portion for discharging the air, and a valve member movably housed in the vertical tubular portion, which permits air flow during operation but, upon shutdown, seals the nozzle and prevents backflow or backsifting of the particulate material.

Abstract: A fluidized bed reactor system and method of operating same, in which a fluidized bed of fine particles is combusted in a reactor forming a mixture of flue gases and relatively fine particles entrained by the flue gases. The mixture is passed to a separator which separates the entrained fine particles from the flue gases. The flue gases are passed to a heat recovery area for the extraction of thermal energy and the separated fine particles are collected in a dipleg seal. A portion of the separated fine particles is passed to the reactor and the remaining portion is discharged to the heat recovery area where the fine particles mix with the flue gases and heat is recovered from the latter mixture.

Abstract: An aeration rod-out assembly for aerating a flow of solids in a pipe is disclosed comprising an aeration pipe with first and second ends, the first end connected to the pipe containing the flow of solids and a cap connected to the second end. A rod is slidably disposed within the aeration pipe and said cap for axial movement therein between first, second and third positions such that as the rod is moved from its first position to its third position the rod ejects from the aeration pipe solids which settle into the housing. A shaft connected to the rod projects from the cap for actuation of the rod. First and second hoses register with the aeration pipe and the cap respectively to deliver aeration gas to the assembly, which gas discharges through the first end of the aeration pipe to aerate the flow of solids when the rod is in its first position but is substantially blocked from discharging when the rod is in or between its second and third positions.

Abstract: A fluidized bed reactor in which partitions disposed within a vessel form first and second furnace sections, first and second troughs and a heat exchange section such that the first trough is disposed between the first furnace section and the heat recovery section and the second trough is disposed between the second furnace section and the heat recovery section. A fluidized bed is formed in each of the furnace sections for the combustion of fuel to generate heat and to generate a mixture of combustion gases and entrained particulate solids. The mixtures from the furnace sections are received in first and second horizontal cyclone separators, both formed within the vessel for separating the entrained particulate solids from the combustion gases. Outlet means extend from the horizontal cyclones to discharge the separated solids to the first and second troughs respectively.

Abstract: A tubular type heat exchanger unit which utilizes upper inlet and outlet headers which are each series connected to at least three lower parallel headers by multiple elongated vertically-oriented tubes. The lower headers are connected together by a plurality of vertically-oriented U-shaped tubes provided in adjacent banks and rows within a thermally-insulated casing. The U-shaped tubes in each tube row are arranged in a staggered pattern relative to the tubes in the adjacent row. Preferably 4-12 lower headers each having a bank of 4-20 vertical tubes are provided. Such heat exchanger unit is enclosed within a thermally-insulated casing and is suitable for use as an economizer and superheater in heat recovery steam generators (HRSG).

Abstract: A fluidized bed reactor in which a sealing section is located within the reactor and adjacent a furnace section located in the reactor. A fluidized bed is formed in the furnace section and the sealing section. A mixture of flue gases and entrained particulate materials from the fluidized bed in the furnace section are separated and the separated particulate material is passed to the fluidized bed in the sealing section. When bed materials in the fluidized bed in the sealing section exceed a predetermined volume they are passed to the fluidized bed in the furnace.

Abstract: A fluidized bed reactor in which a heat exchanger is located adjacent 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 reactor are separated and the separated particulate material is passed to the fluidized bed in the heat exchanger. Coolant is passed in a heat exchange relation with the separated materials in the heat exchanger to remove heat from the materials after which they are passed to the fluidized bed in the reactor. Auxiliary fuel is supplied to the heat exchanger for combustion to control the temperature of the coolant. When the system of the present invention is utilized to generate steam the coolant can be controlled to match the requirements of a steam turbine.

Abstract: A fluidized bed system and method utilizing two stage combustion in which solids in the flue gases from the combustion in the fluidized bed are separated and returned to the bed while the clean flue gases are mixed with gases containing oxygen to effect secondary combustion. The fluidized bed is operated at sub-stochiometric conditions and NOx scavengers are supplied to the flue gases.

Abstract: A cyclone separator formed by a plurality of parallel tubes and a plurality of fins. Each tube is configured in a multitude of segments. One segment of the tubes forms a cylindrical section, one segment is bent inwardly to form a roof section, and one segment is bent inwardly to form a conically-shaped hopper section. As the circumference and diameter of the hopper section decreases from top to bottom, at least a portion of the tubes are configured, either by being extracted or swaged, to accommodate the decreasing circumference and diameter, which results in an increase in the heat recovery of the water-cooled heat transfer tubes without the need for an intermediate ring header.

Abstract: A fluidized bed reactor in which partitions disposed within a vessel form first and second furnace sections, first and second troughs and a heat exchange section such that the first trough is disposed between the first furnace section and the heat recovery section and the second trough is disposed between the second furnace section and the heat recovery section. A fluidized bed is formed in each of the furnace sections for the combustion of fuel to generate heat and to generate a mixture of combustion gases and entrained particulate solids. The mixtures from the furnace sections are received in first and second horizontal cyclone separators, both formed within the vessel for separating the entrained particulate solids from the combustion gases. Outlet means extend from the horizontal cyclones to discharge the separated solids to the first and second troughs respectively.

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 passed first to the stripper section where air is passed through the particulate material at a velocity sufficient to entrain relatively fine portions of the particulate material. A plurality of spaced baffle members are disposed in the stripper section for impacting with the entrained particulate material to separate it from the air. The particulate material in the stripper section is passed to the cooler section in which air is passed through the particulate material at a velocity sufficient to cool the particulate material and entrain relatively fine portions of the particulate material.

Abstract: A fuel feed system and method for feeding low grade fuels to a fluidized bed furnace including an enclosure with a fuel inlet for introducing the fuel into the enclosure, an inlet for introducing air into the enclosure so as to propel the fuel through the enclosure, and baffles disposed in the path of the fuel in a manner to reduce the size of the fuel particles prior to the introduction of the fuel into the furnace.

Abstract: A furnace firing apparatus and method for burning low volatile fuel in which first and second burners are provided to introduce particulate, air-suspended fuel into primary and secondary combustion zones of a combustion chamber. The alignment of the second burner is adjustable and aligned so that the stream of fuel and air introduced by the second burner entrains combustion products produced by the burning of fuel in the primary combustion zone in order to ignite the fuel introduced by the second burner. Secondary air is provided by a pair of plenum chambers to support combustion of the fuel. In an alternate embodiment, an intermediate burner is provided to entrain combustion products from the combustion of fuel introduced by the first burner and whose combustion products are entrained into the fuel introduced by the second burner.

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 combustion system in which a furnace having a fluidized bed disposed therein is divided into multiple sections by one or more partitions. Openings are provided in the lower portion of each partition for permitting the fluidized bed material to flow between the furnace sections, and openings are provided in the upper portion of each partition for equalizing the gas pressure between the furnace sections.

Abstract: A reactor in which a furnace section, a heat recovery section and a horizontal cyclone separator are formed in a vessel. A bed of solid particulate material including fuel is supported in the furnace section and air is introduced into the bed at a velocity sufficient to fluidize same and support the combustion or gasification of the fuel. A mixture of air, the gaseous products of combustion and the particles entrained by the air are directed to the vortex chamber of the cyclone separator through an inlet duct. The helical end of the vortex chamber forces the mixture to spirally circulate within the chamber, where the solid particles of the mixture are separated by centrifugal forces. A central tube extends partially within the vortex chamber and receives the cleaned gases from the low pressure center of the chamber. The portion of the tube behind the helical end of the vortex chamber opens directly into the heat recovery area for passing the clean gases thereto.

Abstract: A tube puller tool assembly for extracting tubes from a tubesheet of heat exchangers. The tool assembly includes an actuator cylinder unit attached to a guide cylinder, having a piston rod attached to a tapered mandrel for expanding multiple fingers of a collet member firmly against the tube inner surface. The collet is initially urged into contact with the tapered mandrel surface by a compression spring provided between the piston rod and collet member, except forward movement of the collet relative to the mandel is limited by a retainer ring in the guide cylinder. In use, the tool assembly is first pressurized to place the collet and mandrel members in an extended forward position, then the tool is inserted into a tube to be pulled, with a guide cylinder being abuted against the tubesheet. The tool is then pressurized to retract the piston and mandrel and thereby radially expand the collet fingers firmly into the tube.

Abstract: A circulating fluid bed reactor comprises a reactor chamber having a circumscribing wall, a particle separator to receive a particle - gas suspension from the reactor chamber, and means for returning the particles separated by the particle separator to the reactor chamber. In order to eliminate problems due to heat expansion of the parts of the reactor and to provide a simple structure, the particle separator has at least one cyclone having a chamber with a cylindrical outer surface forming a part of the circumscribing wall of the reactor chamber.

Abstract: A tube fin trimming machine adapted for clamping and cutting elongated finned structures, such as finned tubes. The trimming machine includes an elongated main frame having at least one guideway, support means attached to the baseplate and adapted for supporting the finned structure a carriage unit longitudinally movable relative to the main frame and guideway, and at least one cutting torch unit movably mounted on the carriage unit. Each cutting torch is mounted above an elongated fin and is moved both longitudinally and laterally relative to the fin, so as to provide a desired elongated tapered shape for the fin. This invention also includes a method for operation of the fin trimming machine to perform desired trimming operations on elongated finned structures, such as finned tubes.