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US 4,235,081 AGranted
Compressed air dryer
AssigneeKellogg-American, Inc.
InventorRalph O. Dowling
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AssigneeKellogg-American, Inc.
InventorRalph O. Dowling
Estimating the term…
An improved compressed air dryer unit having an air-to-air heat exchanger and an air-to-refrigerant heat exchanger separately mounted on a common base plate and connected in series for air flow therethrough in succession. Each exchanger comprises a tubular housing containing a bundle of tubing disposed longitudinally in the housing and extending through holes in a stack of closely spaced parallel sheet metal fins substantially coextensive in area with the cross-sectional area of the chamber in the housing. Longitudinally spaced baffles on the interior walls of the housing direct the flow of air therethrough in a succession of oppositely directed passes around and between the fin sheets. Water vapor, oils and particulates are deposited on the fin sheets and flow due to gravity to the bottom of the housing producing a self-cleaning function on the fin sheets. Water collected in the housing is removed via drain tubes controlled by automatic drain valves. Separate water separators are not required but may be used if desired.
In a compressed air dryer of the type wherein hot moist air flows from a compressor through an air- to-air heat exchanger to an air-to-refrigerant heat exchanger and then back through the air-to-air heat exchanger to dehumidify the air, the improvement wherein each of said heat exchangers comprises a sealed shell formed of substantially identical half-sections joined along their longitudinal edges having therein respective tube bundles, said tube bundles comprising a plurality of closely spaced parallel extending sheet metal fins having holes therein through which the tubes extend longitudinally within said shells, said air-to-air heat exchanger having sealed end chambers at opposite ends thereof into which the tubes of the corresponding tube bundle open, an intermediate chamber provided with an entrance port at one end by which moist compressed air is supplied thereto and an exit port adjacent the opposite end via which the air leaves said intermediate chamber, and baffles on the interior of said shell half- sections for directing the flow of air therethrough in a plurality of oppositely directed passes, said air-to-refrigerant heat exchanger having an entrance port adjacent one end that is connected to the exit port of the air-to-air heat exchanger and an exit port adjacent the opposite end that is connected to one of the sealed end chambers of the air-to-air heat exchanger, and baffles on the interior of said shell half-sections for directing the flow of air in a plurality of oppositely directed passes over the tube bundle of said air- to-refrigerant exchanger, the air from the air-to-refrigerant heat exchanger flowing via the said one sealed end chamber through the tubes of the tube bundle of said air-to-air heat exchanger and exiting via the opposite one of said sealed end chambers, condensed moisture which collects on the fins of said tube bundles falling by gravity to the bottom of said shells, and drainpipe means for draining the moisture from said shells.
The method of operating a compressed air dryer of the type wherein hot moist gas from a compressor flows through an air-to-air heat exchanger to an air-to-refrigerant exchanger and then back through the air-to-air heat exchanger to dehumidfy the air, wherein the improvement comprises flowing the hot moist gas progressively in a series of oppositely directed passes between groups of closely spaced corrugated sheet metal fin elements forming part of the tube bundles in the air-to-air exchanger and then in a series of oppositely directed pases between groups of closely spaced corrugated sheet metal fin elements forming part of the refrigerating tube bundles of said air-to-refrigerant exchanger to capture oil and solid particles and so that the water condensing thereon washes the fin elements, the water collecting on said sheet metal fin elements obviating separators or absorbent material for removing water from the outflow of air from said first heat exchanger.
In a compressed air dryer of the type wherein hot moist air flows from the compressor through an air-to- air heat exchanger to an air-to-refrigerant heat exchanger and then back through the air-to-air exchanger to dehumidfy the air, the improvement wherein the air-to-air heat exchanger comprises a first tubular housing having sealed end chambers and an intermdeiate chamber separated therefrom, a plurality of pipes supported longitudinally in said intermediate chamber and having their opposite ends open respectively to said end chambers, said first housing having an entrance port and an exit port for compressed air in said housing at opposite ends respectively of said intermediate chamber, baffle means on the interior of said first housing to guide the flow of air through the intermediate chamber of said housing from said entrance port to said exit port in a plurality of successive oppositely directed passes, wherein said air-to-refrigerant heat exchanger comprises a second tubular housing, a serpentine refrigeration pipe disposed longitudinally within said second tubular housing, through which a refrigerant medium flows, said second housing having an entrance port for air at one end and an exit port for air at the opposite end thereof, wherein conduit means connects the exit port of the first said housing to the entrance port of said second housing, said second housing having baffle means on the interior thereof to guide the flow of air in successive oppositely directed passes over and around said refrigeration pipe, from the entrance port to the exit port of said second housing, and wherein conduit means connects the exit port of said second housing to one of the sealed end chambers of the said first housing thereby to cause refrigerated dried air to flow through said plurality of pipes therein for initial cooling of air flowing through said first housing.
Dependencies are inferred from the claim text.