- When the vacuum is working, whether the vibration affects the process and environment. We should choose no vibration pump or adopt anti-vibration measures if necessary.
- When choosing the vacuum pump, we must know the composition of the pumped gas, whether there is condensable vapour , dust grains, corrosion and so on. If yes, we should install auxiliary equipment, such as condenser, dirt catcher etc.
- When vacuum pump at the working pressure, it should be able to exhaust all the gas produced in the process.
- Assembling the vacuum pump correctly.
Because the vacuum pump has the selective extraction, sometimes choosing one pump can not meet the pumping requirements, needing several pumps combination, mutual supplement to meet the pumping requirements.
For example, titanium sublimation pump has a high pumping rate for hydrogen, but can not pump helium, and tri-pole sputtering ion pump (or bipolar asymmetric cathode sputtering ion pump) has a certain pumping rate for argon, the combination of the two will make the vacuum device get a better vacuum degree.
In addition, some vacuum pumps can not work under atmospheric pressure, it needs for pre-vacuum; some vacuum pumps’ outlet pressure is lower than atmospheric pressure, it needs for the former pump, so it is necessary to use the pump together.
- Requirements for oil pollution
If the equipment is strictly required to be oil-free, non-oil pump should be selected, such as: water ring pump, molecular sieve adsorption pump, sputtering ion pump, cryogenic pump, etc. If the requirements are not strict, we can choose oil pump, with some anti-oil pollution measures, such as cold trap, baffle, oil trap, etc., can also meet the requirements of clean vacuum.
6. Select the working place of the vacuum pump correctly.
Each pump has a certain range of working pressure. Therefore, the working place of the pump selected in this range is more appropriate, and can not worked in 25~30mmHg for a long time.
- The effect of the oil vapor from the vacuum pump on the environment.
If it does not allowed pollution, we can choose oil-free vacuum pump, or make the oil vapor exhausted to the outdoor.
- The working pressure of vacuum pump should meet the limit vacuum and working pressure requirements.
For example, a vacuum drying process requires a working vacuum of 10mmHg, the ultimate vacuum should be at least 2mmHg, and it is the best if reaching 1mmHg. Usually selecting pump limit vacuum is higher than the vacuum equipment working vacuum half to one order of magnitude.
- The cost of vacuum pump
The cost of vacuum pump including the one-time purchasing cost and comprehensive using cost.
One-time cost, including the vacuum pump price, and the cost of peripheral pipeline supporting;
Comprehensively using cost, including daily operation and maintenance costs, maintenance costs and service life costs.
- Other special requirements.
It mainly includes AC and DC power, power consumption, weight, volume, electronic control, heat dissipation, gas pipeline connection and specific requirements of various industries.