Use vacuum pump

Use vacuum pump When choosing a vacuum pump, you need to pay attention to the following items: 1. The working pressure of the vacuum pump should meet the ultimate vacuum and working pressure requirements of the vacuum equipment. For example: vacuum coating requires 1 times the vacuum degree of 10-5mmHg, the vacuum degree of the selected vacuum pump should be at least 5*10-6mmHg. The vacuum degree of the pump is usually selected to be half to one order of magnitude higher than that of the vacuum equipment. 2. Correctly select the working point of the vacuum pump. Each pump has a certain working pressure range, such as: diffusion pump is 10-3~10-7mmHg, in such a wide pressure range, the pumping speed of the pump changes with the pressure, and its stable working pressure range is 5 times Multiply 10-4~5 by 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. Another example is that the titanium sublimation pump can work under 10-2mmHg, but its working pressure should be less than 1 times 10-5mmHg. 3. Under the working pressure of the vacuum pump, it should be able to remove all the amount of gas generated in the vacuum equipment process. 4. Combine the vacuum pump correctly. Due to the selective pumping of vacuum pumps, sometimes a type of pump cannot meet the pumping requirements, and several pumps need to be combined to complement each other to meet the pumping requirements. For example, the titanium sublimation pump has a high pumping speed for hydrogen, but it cannot pump helium, and the tripolar sputtering ion pump (or the bipolar asymmetric cathode sputtering ion pump) has a certain pumping speed for argon. Both Combined, it will make the vacuum device get a better vacuum. In addition, some vacuum pumps cannot work under atmospheric pressure and require pre-vacuum; some vacuum pumps have an outlet pressure lower than atmospheric pressure and require a foreline pump, so they need to be combined to use the pump. 5. Requirements for oil pollution by vacuum equipment. If the equipment strictly requires no oil, various oil-free pumps should be selected, such as: water ring pump, molecular sieve adsorption pump, sputter ion pump, cryopump, etc. If the requirements are not strict, you can choose to have an oil pump, plus some anti-pollution measures, such as cooling traps, baffles, oil traps, etc., can also meet the requirements of clean vacuum. 6. Understand the composition of the gas being pumped. The gas contains no condensable vapors, particulate dust, or corrosiveness. When choosing a vacuum pump, you need to know the gas composition and select the appropriate pump for the gas being pumped. If the gas contains vapor, particles, and corrosive gases, you should consider installing auxiliary equipment, such as condensers and dust collectors, on the intake line 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 an oil-free vacuum pump, or discharge the oil vapor outdoors. 8. Whether the vibration generated by the vacuum pump has any impact on the process and environment. If the process does not allow, choose a non-vibrating pump or take anti-vibration measures. 9. The price, operation and maintenance cost of the vacuum pump.