Process for recovering argon
AssigneeNihon Sanso Kabushiki Kaisha
InventorHidetake Okada
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Abstract
A process for recovering argon in which a crude argon column is supplied with an argon feed gas containing a larger proportion of oxygen from a double rectifier and is cooled at its head portion with or without liquid air from a sump of the lower column of the double rectifier for producing a reflux of argon in the crude argon column. In the process, argon gas is compressed to a pressure sufficient for evaporating liquid oxygen fed from a condenser of the double rectifier, is then precooled in a heat exchanger, and thereafter liquefied by heat exchange with the liquid oxygen. Then the head portion of the crude argon column is cooled with the liquefied argon, which is then returned in a gaseous state for further compression to thereby circulate the argon gas.
Claims3
In a process for recovering argon in which a crude argon column is supplied with an argon feed gas containing a larger proportion of oxygen from a middle stage of an upper column of a double rectification column for low temperature air separation, the improvement comprising retrofitting an existing process to maximize argon recovery and minimize power consumption while precluding deterioration of rectification conditions in the upper column including the steps of:
- (a) compressing argon gas to a pressure sufficient for evaporating liquid oxygen fed from a condenser of the double rectification column;
- (b) precooling the compressed argon gas in a heat exchanger;
- (c) liquefying the precooled argon gas by heat exchange with liquid oxygen from the condenser of the double rectification column;
- (d) introducing the liquefied argon as a reflux into the head portion of the crude argon column thereby cooling said head portion and evaporating the liquefied argon;
- and
- (e) returning the evaporated argon to the step (a) for further compression to thereby circulate the argon gas.
Dependencies are inferred from the claim text.