Vacuum pump as a part of the Roots fan, in the selection of vacuum pumps need to understand those related knowledge?Roots FansI'll take you through it.
1、The working pressure of the vacuum pump should meet the ultimate vacuum and working pressure requirements of the vacuum equipment.
2、Correctly select the working point of the vacuum pump. Each kind of pump has a certain working pressure range, and its stable working pressure range is 760~60mmHg. Therefore, the working point of the pump should be selected within this range, and it can't let it work under 25~30mmHg for a long time.
3、Vacuum pump should be able to discharge all the gas volume generated in the process of vacuum equipment under its working pressure.
4, the correct combination of vacuum pumps. Because the vacuum pump has selective pumping, therefore, sometimes choose a pump can not meet the pumping requirements, need several kinds of pumps combined, complement each other in order to meet the pumping requirements. Such as titanium sublimation pump for hydrogen has a very high pumping speed, but can not pump helium, and three-pole type sputtering ion pumps, (or two-pole type asymmetric cathode sputtering ion pumps) on the argon has a certain pumping speed, the two combinations, it will make the vacuum device to get a better vacuum degree. In addition, some vacuum pumps can not work under atmospheric pressure, need to be pre-vacuum; some vacuum pump outlet pressure is lower than atmospheric pressure, need to be pumped before the stage, so it is necessary to combine the pumps to use.
5、Vacuum equipment on the oil pollution requirements. If the equipment is strictly required to be oil-free, all kinds of oil-free pumps should be selected, such as: water ring pump, molecular sieve adsorption pump, sputtering ion pump, cryogenic pump, etc. If the requirements are not strict, oil pump can be selected. If the requirements are not strict, you can choose oil pump, plus some anti-oil pollution measures, such as adding cold trap, baffle, oil trap, etc., can also achieve clean vacuum requirements.
6, to understand the pumped gas composition, the gas contains no condensable vapors, there are no particles of dust, corrosive and so on. When choosing a vacuum pump, you need to know the composition of the gas and choose the appropriate pump for the pumped gas. If the gas contains vapors, particles, and corrosive gases, you should consider installing auxiliary equipment, such as condenser, dust collector, etc., on the inlet pipe of the pump.
7、How does the oil vapor discharged from the vacuum pump affect the environment. If the environment does not allow pollution, you can choose oil-free vacuum pump, or the oil vapor discharged to the outdoors.
8、Vibration generated when the vacuum pump is working has no effect on the process and the environment. If the process is not allowed, choose the vibration-free pump or take anti-vibration measures.
9. The price, running and maintenance costs of the vacuum pump.