Separation of air by cryogenic distillation comprises using two columns in association with a reboiled purge column

摘要

Separation of air by cryogenic distillation comprises feeding cold purified compressed air into a first column (K01), condensing overhead gas from K01 in a condenser and returning the condensate to K01, withdrawing oxygen-enriched liquid (OEL) from K01, passing OEL to the top of a purge column (K40), withdrawing OEL from the bottom of K40, and withdrawing OEL from K01, cooling it in the reboiler of K40 and passing it to a second column (K02).