What are the differences between the three types of vacuum pumps, and how to choose one?

This post was last edited by zdl1966 on 2015-12-25 at 15:03. The choice should be based on the operating conditions; the pumping rates of the KT400, ZJP150, and 2×30 rotary vane pumps decrease in sequence.

Vane pumps can achieve high vacuum levels; their disadvantages are the high requirements regarding oil quality, the need for regular replacement of the oil, and their susceptibility to damage caused by water vapor. Rotary vane pumps serve primarily to increase pressure, have a large flow rate, and must be used in conjunction with a pre-pump such as a vane pump

The last edit to this post was made by symc on 2015-12-25 at 16:06. Simply put, if these three types of pumps are to be used in series in a stable and reliable manner, the following points must be taken into consideration: 1. The mass flow rates must be equal; however, due to fluctuations in the compression ratio during actual operation, the mass flow rate of each pump that comes before the next (in the exhaust direction) should be 5% higher than the flow rate of the pump ahead of it (in the suction direction)； 2. The impact of the compression ratio and pressure difference on volumetric efficiency must be taken into account in order to correctly determine the mass flow rate relationship described in point 1, rather than relying on the test flow rates provided by the pump manufacturer ； 3. It is necessary to take into account factors such as suction temperature and medium composition under actual operating conditions, in order to adjust the test flow rate provided by the manufacturer ； 4. Components required for other necessary control logic, etc ； 5. It is necessary to consider the difference between the actual operating pressure and the design pressure, as well as the factors influencing it, such as material evaporation, etc ； 6. A design margin for pressure and flow rate must be taken into account; as mentioned in point 2 above, this margin refers to the margin for the actual flow rate after corrections ；

These three types are connected in series to form a high-vacuum system capable of achieving a pressure of 10(-3 to 6) Pa. The diffusion pump serves as the main pump, the Roots pump acts as the intermediate pump, and the rotary vane pump functions as the final pump for venting air

Configure the solution based on the actual operating conditions in your facility. For the chemical industry, I recommend using dry screw pumps, as they offer a high vacuum level and operate without oil or water; thus, there is no need to worry about oil changes or water-related issues. Additionally, the material can be recycled as well.....

If necessary, you can send us your specific requirements regarding operating conditions, and we can develop the most suitable solution for you to use as a reference