Precautions for vacuum pump selection
1. The limit pressure of the vacuum pump should meet the working pressure of the process. Generally, the limit pressure of the pump is about an order of magnitude lower than the process requirements.
2. Each pump has a certain working pressure range. Therefore, the working point of the pump should be selected within this range, rather than working at the allowable working pressure for a long time.
3. Under its working pressure, the vacuum pump shall be able to discharge all the gas generated in the process of vacuum equipment.
4. Select vacuum unit:
(1) When one pump cannot meet the requirements of air extraction and vacuum, several pumps need to be combined and supplemented to meet the process requirements.
(2) Some vacuum pumps can not work under atmospheric pressure and need pre vacuum; The outlet pressure of some vacuum pumps is lower than atmospheric pressure, and the front stage pump is required, so the pumps need to be combined for use. The combined vacuum pump is called vacuum pump unit, which can make the vacuum system obtain better vacuum degree and exhaust volume. We should correctly select the combined vacuum pump, because different vacuum pumps have different requirements for the extracted gas. For example, under normal circumstances, roots rotary vane unit is not suitable for the system containing more condensable gas.
5. When you choose an oil sealed pump, you should first understand whether your vacuum system has requirements for oil pollution. If the equipment is strictly required to be free of oil, various non oil pumps should be selected, such as water ring pump, cryogenic pump, etc. If the requirements are not strict, an oil pump can be selected, and some oil pollution prevention measures, such as adding cold trap, oil retaining trap, baffle, etc., can also meet the requirements of clean vacuum.
6. Understand the composition of the extracted gas, whether the gas contains condensable steam, whether there is particulate dust, whether it is corrosive, etc. When selecting a vacuum pump, you need to know the gas composition and select the corresponding pump for the pumped gas. If the gas contains steam, particles and corrosive gases, it should be considered to install auxiliary equipment on the air inlet pipeline of the pump, such as condenser, dust collector, etc.
7. When selecting an oil sealed vacuum pump, consider the impact of the oil vapor (oil fume) discharged by the vacuum pump on the environment. If the environment is not allowed to be polluted, an oil-free vacuum pump should be selected, or the oil steam should be discharged outdoors.
8. Whether the vibration generated during the operation of the vacuum pump has any impact on the process and environment. If the process is not allowed, the pump without vibration shall be selected or anti vibration measures shall be taken.
9. Price, operation and maintenance cost of vacuum pump.
Only after we have considered various situations can we determine a solution suitable for you:
(1) Reduced investment costs.
(2) Reduced production and operation costs.
(3) It is a feasible scheme to distribute the first two cases reasonably and evenly.