Future development of cryogenic air separation equipment

In the air separation unit of molecular sieve adsorption purification process, after the air is compressed at the last stage of the air compressor, the temperature out of the air compressor reaches 80-90 ℃. Since the adsorption capacity of molecular sieve is inversely proportional to the temperature, in order to improve the working efficiency of molecular sieve adsorber and ensure the purification effect, the compressed air from the air compressor must be cooled to reduce the temperature of the compressed air before entering the purification system.

The oxygen and nitrogen products produced by the air separation unit in the external compression process are low-pressure oxygen and nitrogen from the upper column, which are sent out of the cold box after being reheated by the heat exchanger. The product gas pressure out of the cold box is generally 0.12MPa. After being compressed to the pressure required by the user by the oxygen compressor, it is sent to the user’s pipeline. The internal compression process of oxygen is that liquid oxygen products are directly extracted from the condensing evaporator, compressed to the user's required pressure by the liquid oxygen pump in the cold box, and then sent to the user's pipeline after reheating and gasification by the heat exchanger.