Deep cooling air separation equipment

The air is mainly composed of 78.03% nitrogen and 20.93% oxygen and other gases. Air separation is to cool the air to a certain low temperature firstly and liquefy it into liquid air. Reuse two liquids oxygen and nitrogen with different boiling points (At atmospheric pressure, the boiling point of oxygen is - 183.98°C and that of nitrogen is - 195.8°C), separation is carried out in an air fractionator equipped with sieve plates. The air separation column is also called distillation column. Air distillation column can be divided into single-stage distillation column and double-stage distillation column, and single-stage distillation column can only produce one kind of pure product. Two stage distillation column is used to produce high purity nitrogen and oxygen in common air separation unit.

The liquid air separation plant includes the lower tower, upper tower, condensing evaporator, argon system, main heat exchanger, subcooler, liquefier and is placed in a separate cold box. After distillation in the lower tower, high purity nitrogen is obtained at the top of the lower tower, which is reheated by the main heat exchanger and then exits the cold box and goes to the nitrogen circulation system to recover the cold from the liquid air separation plant to make liquid nitrogen. The lower ...