Working principle of rotary vane vacuum pumps

The working principle of rotary vane vacuum pump is: the front and rear stage rotors with rotary vane are installed eccentrically in the cylindrical front and rear stage cylinders. When the rotor rotates at a high speed, the rotary vane which is installed in the rotor groove and free to move is forced outward due to centrifugal force and spring force, and its top and the inner wall of the cylinder are close to each other so that the imports and exports on the cylinder are isolated by them.

    A portion of the volume leading to the inlet is gradually and periodically reduced as the rotor rotates. In this way, air or mixed gases are firstly inhaled by the inlet of the high vacuum stage, and then compressed and discharged through its exhaust valve. In the working process, when the exhaust pressure is not enough to push open the exhaust valve, the compressed gas can only enter the second stage to be further compressed and finally discharged to the atmosphere through the second-stage exhaust valve, so that a vacuum is obtained at the suction port of 2XZ series rotary vane vacuum pump.

    The exhaust valve is generally immersed in oil to prevent gas backflow.2XZ series rotary vane vacuum pump oil circulates in the pump and plays the role of lubrication and sealing.

    2XZ series rotary vane vacuum pump is also equipped with a gas ballast valve, the structure of which is similar to the general gas check valve. When the pumped gas contains a small amount of water vapor, open the gas ballast valve to inject air into the exhaust cavity of the pump, which is used to improve the pressure of the exhaust cavity, so that the water vapor does not condense into water in the pump, and thus can be discharged together with the air in order to prevent the oil from being emulsified by the condensed water, thus prolonging the service life of the lubricating oil and improving the pumping performance of the vacuum pump. Open the gas ballast valve pumping, although it can prevent the lubricant from being emulsified by the condensed water, but reduce the ultimate vacuum of the vacuum pump, therefore, the vacuum pump and then pumping out pure air without water vapor, the gas ballast valve should be closed.