Cryogenic rectification system for producing low purity oxygen and high purity oxygen

摘要

A cryogenic rectification system for producing low purity oxygen (119) and high purity oxygen (123) employing an offset dual column (10,11) with bottom reboil of the lower pressure column (11) effected by condensing (20) feed air, with intermediate reboil of the lower pressure column (11) effected by condensing (21) higher pressure column (10) top vapor (92), and with waste nitrogen (110) turboexpansion (30) to generate refrigeration.