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US 5,682,766 AGranted
Cryogenic rectification system for producing lower purity oxygen and higher purity oxygen
AssigneePraxair Technology, Inc.
InventorsDante Patrick Bonaquist, Nancy Jean Lynch
Life of this patent
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Abstract
A cryogenic rectification system having high recovery of both higher purity and lower purity oxygen which employs a side column having a bottom reboiler wherein feed air is partially condensed and the feed air vapor remaining after the partial condensation is turboexpanded prior to rectification.
Claims10
A method for producing lower purity oxygen and higher purity oxygen comprising:
- (A) partially condensing feed air by indirect heat exchange with higher purity oxygen to produce liquid feed air and gaseous feed air;
- (B) turboexpanding the gaseous feed air and passing the turboexpanded gaseous feed air into a medium pressure column;
- (C) separating feed air within the medium pressure column by cryogenic rectification to produce nitrogen-enriched fluid and oxygen-enriched fluid, and passing nitrogen-enriched fluid and oxygen-enriched fluid into a lower pressure column;
- (D) producing nitrogen-richer fluid and oxygen-richer fluid by cryogenic rectification within the lower pressure column, and passing oxygen-richer fluid from the lower pressure column into a side column;
- and
- (E) separating oxygen-richer fluid by cryogenic rectification within the side column into lower purity oxygen and said higher purity oxygen, recovering lower purity oxygen from the side column and recovering higher purity oxygen from the side column.
3 more elements
Apparatus for producing lower purity oxygen and higher purity oxygen comprising:
- (A) a first column, a second column, and a side column having a reboiler;
- (B) a turboexpander, means for passing feed air into the side column reboiler, and means for passing feed air from the side column reboiler into the turboexpander;
- (C) means for passing feed air from the turboexpander into the first column, and means for passing fluid from the first column into the second column;
- (D) means for passing fluid from the second column into the side column;
- and
- (E) means for recovering higher purity oxygen from the side column, and means for recovering lower purity oxygen from the side column above the level from which higher purity oxygen is recovered from the side column.
3 more elements
Dependencies are inferred from the claim text.