How to buy a vacuum pump correctly

With the development of the economy, the quality requirements of the tester instruments have gradually increased, and everyone has become more and more convinced of the brand, and now the power of the brand is becoming stronger and stronger. Then the selection of laboratory vacuum pumps should also be selected with the same vision and attitude. Now there are many brands selling vacuum pumps on the market. If you choose, you should comprehensively measure the five aspects of “brand, performance, quality, service and price”. Pick vacuum pump products.

It is first necessary to check the vacuum required to determine each process. Because each process has its own range of vacuum levels, it must be carefully studied.

Determine the ultimate vacuum

The ultimate vacuum of the vacuum pump system is checked on the basis of determining the degree of vacuum required by the process, since the ultimate vacuum of the system determines the optimum working vacuum of the system. In general, the system's ultimate vacuum is 20% lower than the system's operating vacuum and 50% lower than the foreline's ultimate vacuum.

Type of pumped gas and pumping capacity

Check the type of pumping and the amount of pumping required to determine the process. Because if the type of gas being pumped reacts with the liquid in the pump, the pump system will be contaminated. At the same time, consideration must be given to determining the appropriate exhaust time and the amount of gas produced during the pumping process.

Vacuum volume

Check the time required to reach the required vacuum, the flow resistance and leakage of the vacuum piping. Consider the pumping rate required to maintain the vacuum under certain process requirements after achieving the required vacuum.

The vacuum pump used in the vacuum drying oven and the vacuum concentrator has high requirements. Therefore, when selecting the vacuum pump, it is necessary to pay attention to selecting a vacuum pump with a high vacuum rate and a large pumping rate, such as a rotary vane vacuum pump, to meet the requirements; Rotary evaporators require relatively low vacuum and pumping rates, so you can choose a normal vacuum pump, such as a diaphragm vacuum pump and a circulating water vacuum pump.

The diaphragm vacuum pump can be divided into a primary pump, a secondary pump, a tertiary pump and a four-stage pump according to different degrees of gas treatment. When the primary pump is subjected to a compression treatment of the gas, the effect of pumping and decompressing is achieved. The pump vacuum is low but the pumping capacity is large. The four-stage pump is the function of pumping and decompressing the gas after four times of compression treatment. The four-stage pump has higher technical requirements, and the fourth-stage pump has the highest vacuum but the pumping rate is small. The diaphragm is up to the second level, and the foreign level is up to the fourth level. Therefore, the higher the vacuum degree, the higher the pumping rate is, the more expensive the price is. Therefore, when selecting the vacuum pump, it must be selected according to the actual situation.

Finally, don't forget to consider noise and vibration, which is very important for the experimenter, otherwise your eardrum will be tortured.

At present, the pumps commonly used in the market are mostly imported from Germany, mainly represented by 楷桴 and Chemvak. The quality of 楷桴 is good, but the price is more expensive, Chemvak's products are better at cost.