Classification of dry vacuum pumps

Dry vacuum pump is a kind of mechanical vacuum pump which can start pumping under atmospheric pressure, and can directly discharge the pumped gas into the atmosphere. There is no oil or other working medium in the pump cavity, and the pump’s limit pressure is equal to or close to that of oil-sealed vacuum pump.

Main types of dry vacuum pumps are classified as follows:

1. Dry screw vacuum pump

2, oil-free reciprocating vacuum pump

3. Claw vacuum pump

4, oil-free scroll vacuum pump

The working principle of dry vacuum pump:

1. Dry screw vacuum pump

Dry-type screw vacuum pump is a suction and exhaust device which uses a pair of screw rods to rotate in the pump shell at high speed and reverse synchronously. The two screw rods are supported by bearing and installed in the pump shell after fine dynamic balance correction. There is a certain gap between the screw and the pump shell. Therefore, when the pump works, there is no wear between the screw and the screw. Wipe, smooth operation, low noise, working chamber without lubricating oil, therefore, dry screw pump can be pumped containing a large amount of steam and a small amount of dust in the gas occasion, higher limit vacuum, lower power consumption, energy saving, maintenance-free and so on. It is an upgrading product of oil seal / water ring / jet vacuum pump.

2. oil-free reciprocating vacuum pump

Vacuum pump, also called piston vacuum pump, relies on the reciprocating motion of the piston to periodically change the working volume of the pump cavity (cylinder). The structure of reciprocating vacuum pump is similar to reciprocating piston compressor. When working, the suction pipe is vacuumed and the exhaust pipe passes through the atmosphere. Reciprocating vacuum pump can be used in vacuum distillation, vacuum concentration, vacuum crystallization, vacuum filtration, vacuum drying and concrete vacuum operation.

3. Claw vacuum pump

Claw vacuum pump is composed of multi-stage rotor, each stage has two rotors, two rotors rotate in the opposite direction, suction port and pump cavity connected, pump cavity volume becomes larger and suction, when the rotor closed suction port suction end, after the pump cavity becomes smaller and compressed gas, when the exhaust opening after the pump cavity exhaust, exhaust port closed, then Exhaust is finished, so circulate.

4. oil-free scroll vacuum pump

The scroll disc of a scroll oil-free vacuum pump is a scroll disc structure formed by one or more involute spirals connecting one end with a plane. A pair of scroll disks composed of a static scroll disk and a moving scroll disk constitute the basic pumping mechanism of a scroll oil-free vacuum. For example, in a two-stage scroll oil-free vacuum pump, there are two directions corresponding to the fixed scroll disk, a rotating scroll disk located between the two scroll disks. The relative motion of the dynamic and static vortex disks forms a crescent-shaped vacuum chamber with constant volume change, which makes the gas be sucked in and discharged from the exhaust port, and completes the exhaust cycle.