The working principle of the distillation tower in air separation equipment is mainly based on the difference in boiling points of different components for separation.
Air or liquid air is introduced into the top of the distillation tower, and the mixture begins to vaporize through heating equipment. Each component starts to vaporize at different temperatures based on its boiling point. Lighter components (such as oxygen) vaporize faster, while heavier components (such as nitrogen and argon) vaporize slower. After the mixture vaporizes, a vapor-liquid mixture is formed inside the tower, which continuously rises and falls inside the tower, forming a dynamic equilibrium. In order to increase the contact area between vapor and liquid and promote mass transfer, a series of packing materials (such as Bauer rings, sieve plates, etc.) are installed inside the tower. The gas-liquid mixture comes into contact with the packing surface inside the tower, and continuous transfer occurs between the gas-liquid mixture. During this process, heavy components (such as nitrogen and argon) gradually condense downwards and flow out from the bottom of the tower, while light components (such as oxygen) evaporate upwards. After passing through the packing layer, the light components further gather at the top of the tower, forming a product with higher purity. And the recombined product is collected through a collection device at the bottom of the tower, forming a lower purity by-product.
The steam generated during the separation process needs to be condensed into liquid for recycling and reuse. Usually, cooling water or coolant is used to cool steam and transform it into a liquid state.