There is no difference in nature between gas Air Separation Unit and Liquid Air Separation Unit, which is the problem of how much cold capacity to add. Because liquid air separation device needs to produce a lot of liquid out of the cold box, it requires the cooling unit to produce more cold capacity. For conventional air separation, most of the cooling capacity comes from turbine expander (a small amount of throttling also produces cooling capacity). External compression can produce about 3% ~ 5% (the ratio of gas to oxygen products) of liquid products, internal compression can produce a maximum of 8 ~ 10% of liquid products.

Liquid Air Separation Unit To get more cooling capacity, the most intuitive means: can increase the expansion capacity, increase the temperature before expansion, before expansion gas pressure and so on; Therefore, liquid air separation is mainly used in circulating air compressor or circulating nitrogen compressor to pressurize and then expand, in order to provide more cold capacity, convenient storage, convenient supply, and reduced release.