Air separation unit safe operation

In the fractionating column, the separation of oxygen and nitrogen is realized through the process of two-stage distillation in the upper and lower columns. The distillation process must have ascending air and downflow liquid, and the main function of the condensing evaporator is to exchange heat between the liquid oxygen returned from the bottom of the upper column and the nitrogen rising from the top of the lower column. Condensing evaporator is an indispensable heat exchange equipment in air separation distillation system. In a sense, condensing evaporator is the link between upper column and lower column. The condensing evaporator is also called "main cooling". In the condensing evaporator, the liquid oxygen returned from the upper column absorbs heat and evaporates the gas oxygen; the rising nitrogen in the lower column is condensed into liquid nitrogen due to heat release. A part of the gas oxygen is sent out of the column as the product, and the rest is sent to the upper colu

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.