Application field of air separation equipment

What is the function of the distillation tower in an air separation unit?

In the air separation unit, the water cooling column is a hybrid heat exchange equipment which uses the crude nitrogen to reduce the temperature of the cooling water from the air cooling column after cooling air, so as to provide the air cooling column with recycling. In the water cooling column, the crude nitrogen from the reversible heat exchanger (or accumulator) is 27-28 ℃ and the relative humidity is about 30%, while the temperature of the cooling water from the air cooling column is 35-45 ℃. When the crude nitrogen meets the hot water sprayed, it absorbs heat, thus reducing the water temperature. Generally, the structure of water cooling column is packed column, cyclone plate column and sieve plate column.