Air cooler

When the amount of treated air increases, the rising steam in the distillation column will increase, and the amount of liquid to be condensed in the main cooler will increase accordingly, so it has no effect on the reflux ratio in the column. The purity of oxygen and nitrogen remained unchanged in a certain range with the increase of gas volume, and the output increased proportionally with the increase of gas volume. However, with the increase of the amount of condensate in the main cooler, the heat load of the main cooler increases. When the heat transfer area is insufficient, the temperature difference of the main cooler will inevitably expand, and the pressure of the lower column will increase accordingly. At the same time, with the increase of gas velocity in the column, the amount of downflow liquid increases, and the liquid layer on the tray thickens, which increases the resistance of the tray and the pressure of the upper and lower columns. This will adversely affect the sepa

All low pressure air separation units are usually equipped with nitrogen water precoolers. It mainly uses the unsaturation of nitrogen in sewage to evaporate part of water. As the water evaporates, it absorbs the latent heat of vaporization to lower the temperature of the cooling water, which is then used to cool the treated air and lower the temperature of the air entering the column. Therefore, it includes air cooling column and water cooling column. The basic purpose of setting up nitrogen precooler is to reduce the air temperature entering the air separation column and avoid the temperature fluctuation greatly. Because the inlet air temperature directly affects the operation conditions of the switching heat ex-changer and distillation column, as well as the economy of the whole air separation unit. In the design, the air temperature entering the column is usually set at 30 ° C. When the inlet temperature of the column is higher than the design index during operation, the throttl