초록 ▼

A double column cryogenic rectification system for producing low purity oxygen and high purity nitrogen, preferably at elevated pressure, wherein nitrogen-rich vapor from the higher pressure column is turboexpanded and condensed against lower pressure column intermediate liquid prior to being passed

A double column cryogenic rectification system for producing low purity oxygen and high purity nitrogen, preferably at elevated pressure, wherein nitrogen-rich vapor from the higher pressure column is turboexpanded and condensed against lower pressure column intermediate liquid prior to being passed into the lower pressure column.

대표청구항 ▼

A method for producing low purity oxygen and high purity nitrogen comprising: (A) passing feed air into a higher pressure column and separating the feed air within the higher pressure column by cryogenic rectification into nitrogen-rich vapor and oxygen-enriched liquid; (B) passing oxygen-enriched l

A method for producing low purity oxygen and high purity nitrogen comprising: (A) passing feed air into a higher pressure column and separating the feed air within the higher pressure column by cryogenic rectification into nitrogen-rich vapor and oxygen-enriched liquid; (B) passing oxygen-enriched liquid into a lower pressure column; (C) condensing a first portion of the nitrogen-rich vapor by indirect heat exchange with fluid from the bottom of the lower pressure column to produce first nitrogen-rich liquid, and passing first nitrogen-rich liquid into the lower pressure column; (D) turboexpanding a second portion of the nitrogen-rich vapor and condensing the turboexpanded second portion by indirect heat exchange with fluid from above the bottom of the lower pressure column to produce second nitrogen-rich liquid, and passing second nitrogen-rich liquid into the lower pressure column; (E) separating the fluids passed into the lower pressure column by cryogenic rectification into nitrogen-richer fluid and oxygen-richer fluid; and (F) recovering oxygen-richer fluid from the lower pressure column as product low purity oxygen and recovering nitrogen-containing fluid from at least one of the columns as product high purity nitrogen.