Rotary vane vacuum pump is a kind of oil sealed mechanical vacuum pump, which is one of the most basic vacuum obtaining equipment in vacuum technology. At the same time, in the use of laboratory equipment, rotary vane vacuum pump is an essential laboratory equipment, often used with rotary evaporators, short-range distillation and other laboratory equipment. However, few users use the rotary vane vacuum pump correctly in practice, resulting in some small problems in the use of the rotary vane vacuum pump. Today, let’s talk about ten knowledge points of using the rotary vane vacuum pump to deepen our understanding of the rotary vane vacuum pump.
Ten knowledge points of using vane vacuum pump:
1. Before using the rotary vane vacuum pump, ensure that the pump is clean and prevent sundries from entering the pump. Check the oil level, and fill the oil to the center of the oil mark when the pump is stopped. Too low can not seal the oil on the exhaust valve and affect the vacuum degree. If it is too high, it will cause fuel injection during atmospheric startup. During operation, the oil level has increased, which is a normal phenomenon. The oil shall be clean vacuum pump oil of specified brand, which shall be added from the oil filling hole. After refueling, screw on the plug. The oil should be filtered to avoid sundries entering and blocking the oil hole. Add oil according to the oil mark and add vacuum pump oil. Rotate the three-way valve, so that the suction pipe of the pump is connected with the atmosphere, and isolated from the evacuated container, open the exhaust port.
2. When the ambient temperature is too high, the temperature of the oil increases, the viscosity decreases, the saturated vapor pressure increases, and the limiting vacuum decreases, especially the full pressure measured by thermocouple.
3. Rotary vane vacuum pump shall not be used to pump out gases with high oxygen content, explosiveness and metal corrosion. In addition, it is not suitable to inhale the gas which can react with the pump oil and the gas which contains a lot of water vapor
4. The rotary vane vacuum pump can be started at a time when the air or any vacuum degree is open. If a solenoid valve is installed at the pump port, it shall be operated at the same time with the pump.
5. After the rotary vane vacuum pump operates normally, slowly rotate the three-way valve, so that the suction pipe of the pump is connected with the evacuated container and isolated from the atmosphere.
6. Turn the pulley by hand and check the operation. After there is no abnormal condition, turn on the power supply and pay attention to the direction of rotation.
7. After a period of use, the belt becomes loose and the motor position needs to be adjusted. Pay attention to replenishing the pump oil. If there are sundries or water in the pump oil, replace it with new oil and clean the pump body. It is not allowed to clean the pump body with volatile liquid such as ethanoic acid and acetone. Ten knowledge points of using rotary vane vacuum pump correctly
8. Check that the limit vacuum of Dalian vacuum pump is subject to the compressed mercury vacuum gauge. If the gauge is fully pre pumped and verified, the pump temperature is stable, the pump port is directly connected with the gauge, and the limit vacuum will be reached within 30 minutes of operation.
9. If the relative humidity is high, or the extracted gas contains more condensable steam, it is advisable to open the gas ballast valve after connecting the extracted container, and close the gas ballast valve after 20-40 minutes of movement. Before stopping the pump, open the air ballast valve for no-load movement for 30 minutes to extend the service life of the pump oil.
10. When the rotary vane vacuum pump is stopped, in order to maintain a certain degree of vacuum in the vacuum system, the three-way valve should be rotated to make the vacuum system closed, and the suction pipe of the pump is connected with the atmosphere. Cut off the power and stop the operation. Close the exhaust port and close the pump cover.