The rotor of the rotary vane vacuum pump is installed in the pump shell with a certain eccentricity and is close to the fixed surface of the inner surface of the pump shell. There are two (or more) rotors in the rotor groove. When the rotor rotates, the rotor can slide back and forth along its radial groove and always contact with the inner wall of the pump shell. The rotor rotates with the rotor, and the vacuum pump cavity can be divided into several variable volumes.

Pay attention to the following matters when operating the rotary vane vacuum pump:

1. Check the oil level. It is better to fill the oil to the center of the oil mark when the pump is stopped. If it is too low, it can not seal the oil of the exhaust valve and affect the vacuum degree. If it is too high, it will cause fuel injection when starting with atmosphere. During operation, the oil level rises, which is a normal phenomenon. The specified brand of clean vacuum pump oil is used and added from the oil filling hole. After refueling, screw on the plug. The oil should be filtered to avoid impurities entering and blocking the oil hole.

2. The pump can be started in the atmosphere or any vacuum degree. If the solenoid valve is installed at the pump port, it should be operated with the pump at the same time.

3. When the ambient temperature is too high, the oil temperature will increase, the viscosity will decrease, and the saturated vapor pressure will increase, which will cause the limit vacuum to decrease, especially the full pressure measured by thermocouple. If ventilation and heat dissipation are strengthened or the performance of pump oil is improved, the limit vacuum can be improved.

4. Check the limit vacuum of the vacuum pump with the compression type mercury vacuum gauge as the standard. If the pump temperature is stable after full pre pumping test, the pump port is directly connected with the meter, and the limit vacuum will be reached within 30 minutes of operation. The value measured by the total manometer is related to the errors of pump oil, vacuum gauge and regulation. Sometimes the error may be very large, so it can only be used for reference.

5. 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 vessel, and close the gas ballast valve after 20 ~ 40 minutes of movement. Before stopping the pump, the air ballast valve can be opened for 30 minutes to extend the service life of the pump oil.