Method and apparatus for fluidized steam drying of low rank coals with wet scrubbing

Patent · Tue Jul 29 04:00:00 EDT 1986

OSTI ID:5419309

Draper, R; Wolfe, R W

An apparatus is described for drying low-rank coals containing interstitial water, comprising: a sealed vessel containing means for forming a plurality of successive fluidized beds of solids therein, having means for passing low-rank coal solids thereto at one end and means for removing the low-rank coal solids therefrom at the other end after passage therethrough; heat exchange tubes extending into the sealed vessel at the location of each of the fluidized beds; steam injector means at the other end of the sealed vessel for charging steam into the vessel for passage therethrough countercurrent to the flow of low-rank coal solids to fluidize the same in each of the plurality of successive fluidized beds, and remove water therefrom to form a composite steam flow; means for exhausting the composite steam flow from one end of the sealed vessel; means for spraying water into the composite steam flow after exhaustion from the sealed vessel to remove solids and volatile materials therein, comprising a horizontally extending vessel having a plurality of water sprayers, a reservoir for collecting sprayed water and solids, means for filtering water collecting in the reservoir to remove solids therefrom, and means for recycling the water, after filtering, to the water sprayers; means for heating a first portion of the steam flow, after removal of the solids and volatiles therefrom, and returning the heated first portion to the sealed vessel through the steam injector means; means for heating a second portion of the steam flow, after removal of the solids and volatiles therefrom, and passing the heated second portion through the heat exchange tubes in the sealed vessel to effect heat exchange between the second portion of steam and the low-rank coal; means for discharging the second portion of steam, after passage through the heat exchange tubes; and means for passing the second portion of steam from the heat exchange tubes to the means for discharging the same.

• Assignee: Westinghouse Electric Corp., Pittsburgh, PA
• Patent Number(s): US 4602438
• OSTI ID: 5419309
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
013000* -- Coal
Lignite
& Peat-- Transport
Handling
& Storage
CARBONACEOUS MATERIALS
COAL
COAL RANK
DEVOLATILIZATION
DRYERS
DRYING
ENERGY SOURCES
ENERGY TRANSFER
FLUIDIZED BEDS
FOSSIL FUELS
FUELS
GROUND WATER
HEAT EXCHANGERS
HEAT FLOW
HEAT TRANSFER
HEATING
HYDROGEN COMPOUNDS
INTERSTITIAL WATER
MATERIALS
OXYGEN COMPOUNDS
REMOVAL
SCRUBBING
SEALS
STEAM
WATER
WATER REMOVAL