The packing in the extraction column plays an important role in the extraction process, and the selection of the packing directly affects the mass transfer efficiency and application effect of the extraction column.

There are two common types of extraction column packing: bulk packing and structured packing. Bulk fillers such as lacey ring, Pall ring, ladder ring, etc., they have the advantages of simple structure and low price.

Rasping ring is the earliest used bulk filler, but its mass transfer efficiency is relatively low, and the fluid resistance is large. Bauer ring is improved on the basis of lacey ring, and there is a window in the ring wall, so that the gas-liquid distribution in the packing is more uniform, and the mass transfer efficiency is improved.

The stepped ring further optimizes the structure, its height is only half of the diameter, and one end is flared, the fluid distribution performance is better, and the mass transfer efficiency is higher. Structured packing, such as wire mesh corrugated packing, plate corrugated packing, etc., has the advantages of large specific surface area, uniform fluid distribution and high mass transfer efficiency.

Corrugated wire mesh packing is made of metal mesh, has a very high specific surface area and good wettability, suitable for high mass transfer efficiency, high purity separation occasions, such as the extraction of precision chemical products.

Plate corrugated packing is made of metal plate or plastic plate pressed into a corrugated shape, and then assembled, its structural strength is high, large flux, suitable for large processing capacity of the extraction process.

There are several factors to consider when selecting fillers.

The first is the nature of the material, such as viscosity, corrosion, whether it contains solid particles. For materials with large viscosity, fillers with large porosity should be selected to reduce fluid resistance; For corrosive materials, it is necessary to choose corrosion resistant filler materials, such as ceramics, plastics, etc. Secondly, the requirements of the extraction process, such as mass transfer efficiency,

Processing power, etc. If the mass transfer efficiency is high, the structured packing should be preferred; Bulk fillers may be more suitable for large handling volumes. In addition, factors such as the price of fillers and installation and maintenance costs need to be considered.

Different fillers have different application effects in extraction tower. Reasonable selection of filler can improve the mass transfer efficiency of extraction column, reduce fluid resistance, reduce the amount of extractant, improve product quality and production efficiency.

In practical application, suitable packing should be selected according to the specific material properties and extraction process requirements, considering various factors comprehensively, in order to achieve better performance of extraction tower.