The oil-free vacuum pump has been an essential machine for every enterprise. For example, some food industry, pharmaceutical industry, etc. How to choose oil-free vacuum pump? What should be paid attention to when purchasing oil-free vacuum pump? Generally, we don’t pay much attention to the selection of oil-free vacuum pump when we buy it, but this often leads to various troubles in the later stage and so on. So let’s introduce in detail what we need to pay attention to when choosing oil-free vacuum pump.
How to choose oil free vacuum pump
1. The working pressure of the oil-free vacuum pump shall meet the requirements of the limit vacuum and working pressure of the vacuum equipment. For example, if the vacuum drying process requires a working vacuum of 10mmhg, the vacuum degree of the selected oil-free vacuum pump shall be at least 2mmhg, preferably at most 1mmhg. The ultimate vacuum of the pump is usually chosen to be half of the vacuum of the vacuum equipment.
2. Select the working point of oil-free vacuum pump correctly. Each pump has a certain working pressure range, such as: the working pressure range of 2BV series water ring oil-free vacuum pump is 760mmhg ~ 25mmhg (absolute pressure). In such a wide pressure range, the pumping speed of the pump changes with the pressure, and its stable working pressure range is 760 ~ 60mmhg. Therefore, the working point of the pump should be selected within this range, and it is not allowed to work for a long time under 25-30mmhg.
3. Under the working pressure, the oil-free vacuum pump shall be able to remove all gases produced in the process of vacuum equipment.
4. Correctly combine the oil-free vacuum pump. Due to the selective pumping of oil-free vacuum pump, sometimes the pump can not meet the pumping requirements, and multiple 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 can’t pump helium, and the three pole sputtering ion pump (or the two pole asymmetrical cathode sputtering ion pump) has a certain pumping speed for argon. The combination of the two will make the vacuum device get a better vacuum degree. In addition, some oil-free vacuum pumps can not work under atmospheric pressure and need pre vacuum; some oil-free vacuum pumps need pre pump because the outlet pressure is lower than atmospheric pressure, so they need to be combined.
5. Requirements of vacuum equipment for oil pollution. If the equipment is strictly oil-free, various oil pumps shall be selected, such as liquid ring vacuum pump, screw vacuum pump, vortex vacuum pump, etc. If the requirements are not strict, you can choose to have oil pump, plus some measures of oil pollution, such as adding cold trap, baffle, oil trap, etc., which can also meet the requirements of clean vacuum.
6. Understand the composition of the extracted gas. The gas contains no condensable vapor, no dust and no corrosiveness. When choosing an oil-free vacuum pump, you need to know the gas composition and choose the right pumping gas pump. If the gas contains steam, particles and corrosive gas, please consider installing auxiliary equipment such as condenser and dust collector on the inlet pipe of the pump.
7. What is the impact of the oil vapor discharged from the oil-free vacuum pump on the environment? If the environment does not allow pollution, you can choose oil-free oil-free vacuum pump or drain the oil vapor to the outside.
8. The vibration produced when the oil-free vacuum pump works has no impact on the process and environment. If the process is not allowed, please select non vibration pump or take anti vibration measures.
9. Price, operation and maintenance cost of oil-free vacuum pump.