1. When selecting a vacuum pump, the determined products should ensure that all kinds of gases released in the process can be pumped out smoothly. In the application process of vacuum pump, there are various gas media, such as flammable, explosive, easy to condense, easy to reverse, easy to corrode, etc., so the vacuum pump selected needs to ensure its applicability. For example, the process will produce a large amount of water vapor, and the selected vacuum pump must be suitable for pumping water vapor.
Second, the limit vacuum degree of vacuum pump must be higher than the vacuum degree required by process production, at least one order of magnitude higher, and the equipment is suitable for working in the required working vacuum degree range. The ultimate vacuum degree of vacuum pump is the vacuum degree that can be achieved when the pumping speed is zero. Therefore, in order to ensure the pumping speed of the vacuum pump under the working vacuum, it is necessary to meet the requirement that the limit vacuum degree is greater than the working vacuum degree, and the pumping speed needs to be larger in the interval.
Thirdly, the suction speed of the vacuum pump is greater than the maximum gas discharge in the process. In order to ensure the vacuum degree, the selection of vacuum pump involves continuous degassing in the process, and the pumping speed of vacuum pump or vacuum system should be greater than the maximum degassing in the process. If there are cold traps or baffles in the system, the effective pumping speed after adding cold traps or baffles should be greater than the maximum gas release in the process. If a large amount of deflation occurs suddenly in the process, the effective pumping speed of the system should be appropriately increased, usually to 2-3 times of the maximum deflation.
4. When selecting a vacuum pump, the working medium and manufacturing materials of the selected vacuum pump must meet the technological requirements. In the application of vacuum pump, especially in medicine, chemical industry, battery and other fields. The extracted medium is often corrosive gas, so the equipment should have corresponding anti-corrosion measures. For example, the acid-base gas needs corresponding anticorrosive coating or the pump material is changed to stainless steel for anticorrosion; When there is gas with dust or particles, the dust collector, filter or pump itself is allowed before the pump inlet. ?
Five, in the process of continuous production, the selected vacuum pump must meet the needs of continuous production. If necessary, the standby vacuum pump will be automatically replaced to reduce the production interruption caused by accidents. If the amount of gas released in the process is getting smaller and smaller, a maintenance pump can be set to save energy and reduce consumption.
Economy of using vacuum pump. In the process of vacuum pump selection, when a variety of vacuum pumps can meet the process requirements at the same time, it is necessary to analyze the economy of cost and operating expenses, and select a vacuum pump with good economy, reliable operation, small maintenance and convenient use and maintenance.