Method and device for air separation by two-stage rectification

摘要

A method for air separation by two-stage rectification at low temperatures is described, in which the air to be separated is compressed (in 2 and 3) and divided into two partial currents 4, 5. The first partial current 4 is cooled (in 6) and fed into the first stage 8 of rectification, while the second partial current 5 is recompressed (in 10), cooled (in 6), allowed to expand (in 11), and fed into the second stage 9 of rectification. Before entering the second stage 9, the expanded second partial current 5 is cooled (in 24).