Patent ID: 6279345
Filing Date: 2001-08-28
Classification: F25J

Abstract:
A method for carrying out cryogenic air separation comprising:(A) passing feed air into a cryogenic rectification column and separating the feed air within the column by cryogenic rectification into nitrogen-enriched top fluid and oxygen-enriched kettle liquid;(B) partially vaporizing the oxygen-enriched kettle liquid by indirect heat exchange with nitrogen-enriched top fluid to produce oxygen-enriched kettle vapor and remaining oxygen-enriched kettle liquid;(C) compressing the oxygen-enriched kettle vapor and passing the resulting compressed oxygen-enriched kettle vapor into the cryogenic rectification column;(D) vaporizing remaining oxygen-enriched kettle liquid by indirect heat exchange with nitrogen-enriched top fluid; and(E) recovering some of the nitrogen-enriched top fluid as product nitrogen.