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US 5,675,977 AGranted
Cryogenic rectification system with kettle liquid column
AssigneePraxair Technology, Inc.
InventorNeil Mark Prosser
Life of this patent
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Abstract
A cryogenic rectification system for producing oxygen and nitrogen employing a kettle liquid column which processes oxygen-enriched kettle liquid from a higher pressure column and which is reboiled by a fluid taken from below the top of the higher pressure column.
Claims10
A cryogenic rectification method for producing oxygen and nitrogen comprising:
- (A) passing feed air into a higher pressure column and separating the feed air within the higher pressure column by cryogenic rectification into oxygen-enriched kettle liquid and nitrogen-enriched top fluid;
- (B) passing oxygen-enriched kettle liquid into a kettle liquid column and producing intermediate vapor and intermediate liquid by cryogenic rectification within the kettle liquid column;
- (C) passing a vapor stream taken from below the top of the higher pressure column in indirect heat exchange with intermediate liquid to produce higher pressure liquid and passing higher pressure liquid into the higher pressure column;
- (D) passing fluid from the kettle liquid column into a lower pressure column and producing nitrogen-richer fluid and oxygen-richer fluid by cryogenic rectification within the lower pressure column;
- and
- (E) recovering at least some of the oxygen-richer fluid as product oxygen and recovering at least some of at least one of the intermediate vapor, the nitrogen-enriched top fluid and the nitrogen-richer fluid as product nitrogen.
3 more elements
Cryogenic rectification apparatus for producing oxygen and nitrogen comprising:
- (A) a first column, a second column, and means for passing feed air into the first column;
- (B) a kettle liquid column having a bottom reboiler, and means for passing fluid from the lower portion of the first column into the kettle liquid column;
- (C) means for passing fluid from below the top of the first column into the kettle liquid column bottom reboiler, and means for passing fluid from the kettle liquid column bottom reboiler into the first column;
- (D) means for passing fluid from the kettle liquid column into the second column;
- and
- (E) means for recovering fluid from the lower portion of the second column, and means for recovering fluid from the upper portion of at least one of the first column, the second column and the kettle liquid column.
3 more elements
Dependencies are inferred from the claim text.