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US 5,245,832 AGranted
Triple column cryogenic rectification system
AssigneePraxair Technology, Inc.
InventorMark J. Roberts
Life of this patent
Estimating the term…
Abstract
A direct sequenced three column cryogenic rectification system wherein material flow is unidirectional from higher to lower pressure through the system enabling high recovery of each of the three major components of feed air.
Claims9
A method for producing nitrogen, oxygen and argon product by the cryogenic rectification of air comprising:
- (A) introducing feed air into a first column operating at a pressure within the range of from 150 to 350 psia and separating the feed air by cryogenic rectification within the first column into nitrogen-enriched vapor and oxygen-argon-enriched fluid;
- (B) passing oxygen-argon-enriched fluid from the first column into a second column operating at a pressure less than that of the first column and having a bottom reboiler, and separating oxygen-argon-enriched fluid by cryogenic rectification within the second column into nitrogen-rich vapor and oxygen-argon-rich fluid;
- (C) condensing nitrogen-enriched vapor by indirect heat exchange with oxygen-argon-rich fluid in the second column bottom reboiler to produce nitrogen-enriched liquid and oxygen-argon-rich vapor, employing nitrogen-enriched liquid as reflux liquid for the first column, and employing oxygen-argon-rich vapor as reflux vapor for the second column;
- (D) passing oxygen-argon-rich fluid from the second column into a third column operating at a pressure less than that of the second column and having a bottom reboiler, and separating oxygen-argon-rich fluid by cryogenic rectification within the third column into argon-rich fluid and oxygen-rich fluid;
- (E) recovering a first portion of nitrogen-rich vapor as product nitrogen;
- (F) condensing a second portion of nitrogen-rich vapor by indirect heat exchange with oxygen-rich fluid in the third column bottom reboiler to produce nitrogen-rich liquid and oxygen-rich vapor, employing nitrogen-rich liquid as reflux liquid for the second column, and employing oxygen-rich vapor as reflux vapor for the third column;
- and
- (G) recovering oxygen-rich fluid as product oxygen and argon-rich fluid as product argon.
5 more elements
Apparatus for producing nitrogen, oxygen and argon product by cryogenic rectification comprising:
- (A) a first column having feed introduction means;
- (B) a second column having a bottom reboiler, means for passing fluid from the lower portion of the first column into the second column, and means for passing fluid from the upper portion of the first column into the second column bottom reboiler and from the second column bottom reboiler into the first column;
- (C) means for recovering product from the second column;
- (D) a third column having a bottom reboiler, means for passing fluid from the second column into the third column, and means for passing fluid from the upper portion of the second column into the third column bottom reboiler and from the third column bottom reboiler into the second column;
- (E) means for recovering product from the lower portion of the third column;
- and
- (F) means for recovering product from the upper portion of the third column.
4 more elements
Dependencies are inferred from the claim text.