How Does Vacuum Filtration Equipment Work?

As a kind of liquid purification equipment, vacuum filtration is mainly and widely applied to the pharmaceutical and chemical industry and has very amazing using effects. Today Hawach going to introduce some operating principles of this equipment and hope you can reference and understand.

What is vacuum filtration?

Vacuum filtration forms negative pressure in the filtrate outlet as the power of filtration. This kind of filtration machine is split into batch operation and continuous operation.

Vacuum filtration equipment with batch operation can filter suspension liquid with all kinds of concentrations, while another kind with continuous operation can filter thick suspension liquid with more solid particles. With the advantages of lightweight and is easy to install and maintain, it is mainly used in the manufacturing technique of the pharmaceutical and chemical industry and oil industries.

Vacuum filtration includes a vacuum negative pressure filter, which is divided into two kinds of filters. One uses glass with many holes to support the filter membrane, such as Glass Triple-Branches Lab Vacuum Filtration System. It can make sure the left particles distribute on the filter membrane evenly, which makes it easy to gather and count the particles. Another kind uses stainless steel mesh with a PTFE coating to support the membrane, such as Stainless Steel Triple-Branches Vacuum Filtration Unit. It is applied to gather the filtrate, for example, getting rid of particles in the sample. When we filter some thicker liquid, like gathering particles from oil, we suggest this kind of filter. And it is easy to clean.

Six-Branches Stainless Steel Vacuum Filtrations
Glass Three-Branches Vacuum Filtrations
500ml Glass Solvent Filters

Filtering circulation

First, we divide the vessel into the upper house and nether house by filtering medium, which means making up an easy filter. We put the suspension liquid into the upper house and under pressure, it goes through the filtering medium, then into the nether house, and turns into the filtrate. The solid particles are left on the surface of the filtering medium as filter residue. Of course, during the filtering process, the filter residue on the filter medium would be thicker and thicker, and the filtering speed would be slower and slower. When the filtering house is filled with residue, it would stop filtering. And at this moment, it is time to clean the residue and regenerate the filter medium.


1. Check the outlet and inlet tubes are installed in the right way.
2. Open the vent valve before you open the reagent valves.
3. Check the voltage before you start the motor.
4. The solvent filter is fragile and must not be moved in its entirety, especially not with a clip.
5. Selection of filter membrane should be qualified products, unqualified ones will dissolve impurities, soak the solvent to be filtered for 24 hours to see if there is a dissolution phenomenon, in order to examine the quality of the filter membrane.
6. The filter membrane is divided into organic and water systems, and the operator needs to distinguish them.
7. For water-based filtration, the organic membrane is organic, mixed after filtration. Choose the larger proportion for the mobile phase after mixing.
8. The membrane has no front or backside, but the smooth side up, and the rough side down will have a better filtering effect.
9. Do not discard the waste filter membrane at will. The filter membrane is polluting the environment and should collect and go process together.
10. When the oil-free vacuum pump supporting the solvent filter is pumping, do not pull the hose after the liquid is empty, it is not suitable to pull it out, which will flatten the hose, and stop the pump when there is a little liquid left.
11. Filter the solvent to avoid secondary pollution