US 4,301,771 AGranted

Fluidized bed heat exchanger with water cooled air distributor and dust hopper

AssigneeDorr-Oliver Incorporated

InventorsWalfred W. Jukkola, Albert M. Leon, Garritt C. Van Dyk, Jr., Daniel E. McCoy, Barry L. Fisher, Timothy L. Saiers, Marlin E. Karstetter

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Abstract

A fluidized bed heat exchanger is provided in which air is passed through a bed of particulate material containing fuel. A steam-water natural circulation system is provided for heat exchange and the housing of the heat exchanger has a water-wall type construction. Vertical in-bed heat exchange tubes are provided and the air distributor is water-cooled. A water-cooled dust hopper is provided in the housing to collect particulates from the combustion gases and separate the combustion zone from a volume within said housing in which convection heat exchange tubes are provided to extract heat from the exiting combustion gases.

Claims10

Dependent claims

A fluidized bed heat exchanger comprising a housing, a reaction chamber within the housing, means for introducing air into said reaction chamber including a windbox region below said reaction chamber and an air distributor therebetween, an integral water-cooled floor and bridgewall assembly in said housing, a convection heat exchange chamber above said reaction chamber within said housing and separated from said reaction chamber by a slanted baffle, said baffle defining a gas passageway between said reaction chamber and said convection heat exchange chamber and having a hopper portion whereby dust is collected and removed from gases passing through said convection heat exchange chamber, means for establishing a bed of particulate material containing fuel in said reaction chamber, said bed of particulate material being subject to fluidization by air passing into said reaction chamber from said windbox region through said air distributor, a steam drum in said convection heat exchange chamber, an array of tubes each connected at one end to said steam drum and passing through said reaction chamber and into and through said air distributor to connect with a header, said array of tubes having a vertical orientation in that portion of the reaction chamber occupied by said fluidized bed of particulate material, the walls of said housing in the region of said reaction chamber being water-cooled, said integral water-cooled floor and bridgewall assembly formed to provide said air distributor, one of said housing walls, and said baffle, valve controlled conduit means within said housing and extending from said hopper portion of said baffle to a discharge port opening into said reaction chamber below the upper surface of said fluidized bed.

A fluidized bed heat exchanger comprising a housing,

means for introducing fuel and air into said housing for combustion therein,
said housing having therein a unitary floor and bridgewall assembly,
said unitary floor and bridgewall assembly defining and separating within said housing a combustion chamber, a windbox region below said combustion chamber and a convection heat exchange chamber above said combustion chamber,
said unitary floor and bridgewall assembly comprising a skeletal array of coolant tubes for circulation of a coolant therethrough to prevent overheating of said assembly,
the surfaces of said assembly which are exposed in said combustion and convection chambers having a protective layer of refractory thereon,
a floor portion of said unitary floor and bridgewall assembly having perforations therethrough constituting an air distributor for air traversing said perforations from said windbox to said combustion chamber,
a baffle portion of said unitary floor and bridgewall assembly having a sloped orientation within said housing, and, at the upper end thereof, defining a gas port between the edge of said baffle portion and one wall of said housing to accommodate the gases flowing from said combustion chamber to said convection chamber,
a wall portion of said unitary floor and bridgewall assembly forming one wall of said combustion chamber and joining said floor portion to said baffle portion so that cooling water may be circulated successively through the coolant tubes of said floor portion, said wall portion and said baffle portion,
the upper section of said baffle portion forming a planar baffle and the lower section forming a v-shaped hopper so that dust dropped by the exhaust gas in said convection chamber slides down the planar baffle and is channeled by the hopper to a conduit for removal from said convection chamber and
heat exchange means in said housing for extracting heat from the combustion gases generated therein.

7 more elements

Dependencies are inferred from the claim text.