In recent years, has developed a new vacuum from atmospheric pressure to high vacuum, with only one pump will be able to achieve. But in general, in order to obtain a high vacuum, high vacuum and ultrahigh vacuum, vacuum pump or a plurality of units connected in series to form complete evacuation task. Therefore, a proper understanding of the pump works, the main performance, structural characteristics and classification, etc., for the user to select affordable vacuum pump is very important.
The vacuum pump is used to generate, improve and maintain the vacuum apparatus. According to their works, basically divided into gas transmission pump and pump gas trap types.
Gas transfer pump, which is a suction and discharge of the gas can continue to reach the outside of the pump suction port of the vacuum pump. The gas transfer pumps and positive displacement pumps contain two categories momentum transfer pump.
1, volume pump
Vacuum pumps is to use periodically varying volume of the chamber to complete intake, compression and exhaust means. Exhaust gas is compressed before this reciprocating ,This pump is divided into two kinds of reciprocating and rotary.
(1) reciprocating pumps, the use of the reciprocating motion of the pump piston chamber, the gas is sucked, compressed and discharged. Therefore, they call it the piston pump.
(2) rotary vane vacuum pumps, rotary motion of the piston pump chamber, the gas inhalation, compressed and discharged. Many species belong to this pump.
1) mechanical pump seal, it is the use of various oils seal the gap between the moving parts, reducing a rotary positive displacement pump hazardous space. This pump is usually with gas ballast device, so that the gas ballast vacuum pumps, divided according to their structural characteristics: rotary vane pumps, fixed vane pump, rotary piston pump, trochoid pump and multi-chamber rotary vane pumps.
2) the current so-called dry vacuum pump dry vacuum, the general common argument is: vacuum pump capable of operating within a pressure range from atmospheric pressure to 10-2Pa; in pump pumping flow channels (such as a pump chamber), you can not use any oils and liquid seal. exhaust port to atmosphere, the exhaust gas can be continuously supplied to the air pump, i.e., referred to the dry vacuum pump. Divided according to their works, but also the volume of dry vacuum pumps, vacuum pumps, such as multi-level, multi-stage piston pump, claw-type pumps, screw pumps, vortex pumps, etc.; in addition to moving the transmission type dry pumps as turbines two dry pumps, centrifugal pumps dry, etc. This is no longer pump pumping oil pollution, and the recent development of more kinds of pumps.
3) liquid ring vacuum pump, with a multi-blade rotor eccentrically mounted in the pump housing, when the rotor rotates, the liquid (water or oil) threw the pump casing to form concentric shells with liquid ring pump, the liquid ring and the rotor leaves forming a volume of several small volume changes periodically to achieve suction, compression and exhaust. role play due to the compressed gas liquid ring so it is also called liquid piston pump.
4) Roots vacuum pump contains two opposite directions of rotation of the synchronous rotor leaf or double leaf, intertrochanteric, are maintaining a certain gap between the rotor and the casing inner wall. It belongs to no internal compression vacuum pump. According to use is divided into a wet vacuum pumps, vertical atmospheric Roots and mechanical booster pumps and other types.