What is vacuum filtration?
Vacuum filtration (or suction filtration) is an essential technology for distillation, extraction and purification. Compared with the traditional gravity assisted filtration, adding vacuum to the system can greatly improve the speed and efficiency of the laboratory. One of the most common uses is to separate solids from liquids.
Filtration and solid phase extraction
Accelerate filtration by means of pressure or vacuum. For vacuum filtration, regulation and final vacuum requirements are usually not high. At 100 mbar for vacuum filtration, 90% of atmospheric pressure can be used as the driving force for filtration. Further improvement of vacuum will only have a small impact on the process. However, in some cases, a two-stage pump with a higher pumping speed may speed up the filtration process. In these cases, it is recommended to control the vacuum by means of a manual vacuum regulating valve device with a vacuum gauge, for example, to avoid solvent evaporation from the filter bottle.
1. Medium vacuum, best medium requirement
2. According to the filter size and leakage rate, the pumping speed of vacuum pump is an important parameter
3. The filtering speed is partly affected by the consistency of filter cake
4. Limited demand for vacuum control of filtration
5. For solid-phase extraction, it is necessary to determine the flow rate or drop rate, which may need to be controlled
Requirements for vacuum pump:
1. Single stage vacuum pump, with a maximum vacuum of 70 mbar, is an ideal choice
2. Excellent chemical resistance and vapor resistance, suitable for solid phase extraction or filter samples containing solvents
3. Manual control valve and vacuum gauge are very helpful for determining flow or drip rate
4. It is recommended to use a vacuum inlet collection tank (AK) to protect the pump from particles and drops
5. Discharge the condenser for solvent recovery to minimize the impact of solvent vapor on the environment and laboratory air
6. Chemical pump with electronic vacuum controller can realize the automation of filtration process
Piston vacuum pump (also known as piston vacuum pump), It belongs to one of the low vacuum equipment, and its limit pressure is generally 1330-2660p a. Its pumping speed range is relatively large, from 50L / s to 600L / s, which is suitable for vacuum impregnation, liquid steel vacuum treatment, vacuum distillation, vacuum evaporation, vacuum concentration, vacuum crystallization, vacuum drying, vacuum filtration and vacuum operation of concrete in petroleum, chemical industry, medicine, food, light industry, metallurgy, electrical and other industries.
The piston vacuum pump is not suitable for pumping the gas with high oxygen content, explosive, corrosive to metal and containing particle dust, nor for transporting the gas from one container to another as a delivery pump.