Packing specification refers to the nominal size or specific surface area of the packing.
(1) Selection of bulk packing specifications
The bulk packing commonly used in industrial towers mainly has DN16, DN25, DN38, DN50, DN76 and other specifications.
For similar packing, the smaller the size, the higher the separation efficiency, but the resistance increases, the flux decreases, and the packing cost also increases a lot. However, the application of large-size packing in a small-diameter tower will produce poor liquid distribution and serious wall flow, which will reduce the separation efficiency of the tower.
Therefore, there must be a regulation on the ratio of the tower diameter to the packing size. Generally, the ratio D/d of the tower diameter to the nominal diameter of the packing should be greater than 8.
(2) Selection of structured packing specifications
There are many ways to express the types and specifications of structured packing commonly used in the industry. It is customary to use specific surface area in China to express it, mainly including 125, 150, 250, 350, 500, 700 and other specifications.
For the same type of structured packing, the larger the specific surface area, the higher the mass transfer efficiency, but the resistance increases, the flux decreases, and the packing cost also increases significantly.
When selecting, comprehensive consideration should be given to separation requirements, flux requirements, site conditions, material properties and equipment investment, operating costs, etc., so that the selected packing can not only meet the technical requirements, but also have economic rationality.