Filing Information

Inventor(s)	Henry E. Howard ·
Assignee(s)	Praxair Technology, Inc. ·  View assignee updates
Attorney/Agent(s)	Stanley Ktorides ·
Primary Examiner	Henry A. Bennet ·
Assistant Examiner	Christopher B. Kilner ·
Application Number	US7842494
Filing date	02/27/1992
Issue date	07/20/1993
Predicted expiration date	02/27/2012
U.S. Classifications	62/646  · 62/924  · 62/912  · 62/939  ·
International Classifications	F25J 102  ·
Kind Code	A
International Classifications	6222;27;28;31;34;44;24;40 ·

Patent Family

Abstract

A cryogenic rectification system wherein condensed heat pump fluid is subcooled in the upper portion of an argon column, cools incoming feed, and is compressed and then condensed against cryogenic rectification plant bottoms for reboil thus improving reflux ratios and increasing argon recovery.

Independent Claims | See all claims (12)

1. 1. A method for separating air by cryogenic rectification comprising:(A) providing cooled feed air into a cryogenic rectification plant comprising at least one column and separating the feed air in the cryogenic rectification plant by cryogenic rectification to produce nitrogen-enriched fluid and oxygen-enriched fluid;(B) passing argon-containing fluid from the cryogenic rectification plant into an argon column and separating the argon-containing fluid in the argon column by cryogenic rectification to produce crude argon and oxygen-richer fluid;(C) withdrawing heat pump vapor having an argon concentration of at least 80 percent argon from the upper portion of the argon column, warming the withdrawn heat pump vapor, compressing and warmed heat pump vapor and cooling the compressed heat pump vapor; and(D) condensing the cooled, compressed heat pump vapor by indirect heat exchange with oxygen-enriched fluid produced in the lower portion of the cryogenic rectification plant and passing resulting condensed heat pump fluid into the argon column.
2. 7. Cryogenic air separation apparatus comprising:(A) a main heat exchanger, a cryogenic rectification plant comprising at least one column, an argon column, means for providing fluid from the main heat exchanger into the cryogenic rectification plant and means for providing fluid from the cryogenic rectification plant into the argon column;(B) a heat pump compressor, means for providing fluid having an argon concentration of at least 80 percent percent argon from the upper portion of the argon column to the main heat exchanger and from the main heat exchanger to the heat pump compressor;(C) means for providing fluid from the heat pump compressor to the main heat exchanger and from the main heat exchanger to the lower part of the cryogenic rectification plant; and(D) means for providing fluid from the lower part of the cryogenic rectification plant to the upper portion of the argon column.