Columns is a vertical equipment used in industrial production, primarily for separation, absorption, distillation, reaction and other processes of gas and liquid. It is widely used in chemical, petroleum, pharmaceutical, environmental protection and other industries. The interior of columns is usually equipped with packing or plates to increase the contact area between gas and liquid or liquid and liquid, so as to improve the mass transfer efficiency. According to its use and internal structure, columns can be divided into various types, such as distillation column, absorption column, extraction column, reaction column, etc.