Patent ID: 6397632
Filing Date: 2002-06-04
Classification: F25J,Y10S

Abstract:
A method for producing argon by cryogenic rectification comprising:(A) passing feed air into a higher pressure column of a cryogenic air separation plant which also comprises a lower pressure column and an argon column having a top condenser, and separating the feed air by cryogenic rectification within the higher pressure column to produce oxygen-enriched liquid and nitrogen-enriched vapor; (B) passing argon-containing fluid from the lower pressure column as feed into the argon column and producing crude argon vapor by cryogenic rectification within the argon column; (C) withdrawing oxygen-enriched liquid from the higher pressure column and mixing liquid nitrogen with oxygen-enriched liquid withdrawn from the higher pressure column to produce a liquid refrigeration mixture; (D) condensing at least some of the crude argon vapor by indirect heat exchange with the liquid refrigeration mixture in the argon column top condenser to produce crude argon liquid and vaporized refrigeration mixture; (E) passing vaporized refrigeration mixture from the argon column top condenser into the lower pressure column; and (F) recovering some of at least one of the crude argon vapor and crude argon liquid as product argon.