Things to pay attention to when choosing vacuum pump

1. The working pressure of the vacuum pump should meet the limit vacuum and working pressure requirements of the vacuum equipment. For example, vacuum coating requires a vacuum degree of 1×10-5mmHg, and the vacuum degree of the selected vacuum pump should be at least 5×10-6mmHg. Usually, the vacuum degree of the selected pump is half to an order of magnitude higher than the vacuum degree of the vacuum equipment.

2. Correctly select the working point of the vacuum pump. Each pump has a certain range of working pressure, such as: diffusion pump 10-3~10-7mmHg, in such a wide range of pressure, pump pumping speed changes with pressure, its stable working pressure range is 5×10-4~5×10-6mmHg. Therefore, the working point of the pump should be selected within this range, and it should not be allowed to work for a long time under 10-8mmHg.

3, the vacuum pump under its working pressure, should be able to discharge all the gas generated in the process of vacuum equipment.

4. Correctly combine the vacuum pump. Because the vacuum pump has selective pumping, sometimes a pump can not meet the pumping requirements, and several pumps need to be combined to supplement each other to meet the pumping requirements. In addition, some vacuum pumps can not work at atmospheric pressure, need pre-vacuum; Some vacuum pump outlet pressure is lower than atmospheric pressure, the need for the front pump, so it is necessary to combine the pump to use.

5, vacuum equipment for oil pollution requirements. If the equipment is strictly required to be oil-free, a variety of non-oil pumps should be selected, such as: water ring pumps, cryogenic pumps, etc. If the requirements are not strict, you can choose to have oil pumps, plus some anti-oil pollution measures, such as cooling traps, baffle plates, oil traps, etc., can also meet the clean vacuum requirements.

6. Understand the composition of the gas being pumped, whether the gas contains condensable vapor, whether there is particulate dust, whether there is corrosion, etc. When selecting a vacuum pump, it is necessary to know the gas composition and select the corresponding pump for the pumped gas. If the gas contains vapor, particles, and corrosive gases, it should be considered to install auxiliary equipment on the pump inlet pipe, such as condenser, dust collector, etc.

7. What is the impact of the oil vapor discharged from the vacuum pump on the environment? If the environment is not allowed to have pollution, you can choose an oil-free vacuum pump, or exhaust the oil vapor to the outside.

8. Whether the vibration generated by the vacuum pump during operation has an impact on the process and the environment. If the process does not allow, should choose non-vibration pump or take anti-vibration measures.