Pump type determination
The type of pump is mainly determined by the amount of air, vacuum or exhaust pressure required for the job.
When the pump is working, you need to pay attention to the following two aspects:
1. As far as possible, operate in the high efficiency zone, that is, in the area of critical vacuum or critical exhaust pressure.
2. Avoid operating near vacuum or exhaust pressure. Operating in this area is not only inefficient, but also unstable in operation and prone to vibration and noise. For vacuum pumps with a high degree of vacuum, cavitation often occurs in this area, and the obvious sign of this phenomenon is noise and vibration in the pump. Cavitation can cause damage to parts such as the pump body and impeller, so that the pump cannot work.
According to the above principle, when the vacuum or gas pressure required by the pump is not high, it can be selected firstly in the single-stage pump. If the degree of vacuum or exhaust pressure is high, the single-stage pump is often not satisfied, or the pump is required to have a large volume at a higher vacuum, that is, the performance curve is required to be flat at a higher vacuum, and two are optional. Stage pump. If the vacuum is required to be above -710mmHg, an optional water ring-atmosphere pump or water ring-Roots vacuum unit can be used as the vacuuming device.
If it is only used as a vacuum pump, it is better to use a single-acting pump. Because the single-acting pump is simple in construction, easy to manufacture and maintain, and has good cavitation resistance under high vacuum conditions.
If only a large volume compressor is used, it is more suitable to use a double acting pump. Because the double-acting pump has a large gas volume, small volume, light weight, and the radial force can be automatically balanced, the shaft is not prone to fatigue fracture, and the service life of the pump is long.
Select the vacuum pump according to the amount of gas required by the system
After the initial selection of the pump type, for the vacuum pump, the pump model is also selected according to the amount of gas required by the system.