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US 5,440,884 AGranted
Cryogenic air separation system with liquid air stripping
AssigneePraxair Technology, Inc.
InventorsDante P. Bonaquist, Michael J. Lockett
Life of this patent
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Abstract
A cryogenic rectification system which advantageously separates feed air wherein the thermodynamic irreversibility of the argon column top condenser and the lower pressure column is reduced by using a stripping column upstream of the double column main plant.
Claims16
A method for the cryogenic rectification of feed air employing a double column main plant, comprising a higher pressure column and a lower pressure column, and an argon column having a top condenser, comprising:
- (A) condensing a portion of the feed air to produce liquid feed air;
- (B) passing liquid feed air and gaseous feed air into a stripping column and passing liquid feed air against gaseous feed air in the stripping column to produce stripping column product gas, having a nitrogen concentration which exceeds that of air, and stripping column product liquid, having an oxygen concentration which exceeds 25 mole percent;
- (C) passing stripping column product gas into the higher pressure column for separation by cryogenic rectification;
- (D) at least partially vaporizing stripping column product liquid by indirect heat exchange with argon-containing fluid in the argon column top condenser to produce oxygen-containing gas;
- and
- (E) passing oxygen-containing gas into the lower pressure column for separation by cryogenic rectification.
3 more elements
A cryogenic rectification apparatus comprising:
- (A) a double column main plant comprising a first column and a second column, and an argon column having a top condenser;
- (B) a stripping column, means for passing liquid into the upper portion of the stripping column, and means for passing gas into the lower portion of the stripping column;
- (C) means for passing fluid from the upper portion of the stripping column into the first column;
- (D) means for passing fluid from the lower portion of the stripping column into the top condenser;
- and
- (E) means for passing fluid from the top condenser into the second column.
3 more elements
Dependencies are inferred from the claim text.