ZJ Roots Vacuum Pump


一、Overview of ZJ series roots vacuum pump:

What ZJ had roots vacuum pump series, a rotary without internal compression varactor type vacuum pump, also known as mechanical booster pump, its advantage is in low inlet pressure has high extraction rate, it is currently available in one of the main extraction equipment, high vacuum, its working principle are similar to those of roots blower, mainly composed of a pair of synchronous high-speed "8" glyph of rotor and two semicircle pump cavity (as shown in figure 1). Can what ZJ had series roots vacuum pump exhaust alone, must with the former pump (e.g., slide valve pumps, rotary vane vacuum pumps, water ring type vacuum pump, oil pump, etc.) in series, to be the pressure in the pump system is the front-end of the roots vacuum pump vacuum pump can accept pressure to begin to work, otherwise it will damage due to overload and overheating. The vacuum degree of the former pump can be improved in tandem with ZJ series roz vacuum pump in front of the front pump inlet, which can greatly increase the pumping rate in the effective range. The ultimate pressure of ZJ series roz vacuum pump is determined by the former pump, and the data in the technical parameter table is the minimum limit pressure of the standard configuration (double-stage oil sealed mechanical vacuum pump).

What ZJ had series roots vacuum pump in the wide pressure range (1 x 10 1 ~ 4 pa) have large pumping speed, has been pumping gas containing dust and water vapor is not sensitive, so widely used in vacuum casting, vacuum smelting, vacuum degassing, vacuum coating industry and chemical pharmaceutical industry of vacuum distillation, vacuum drying, etc.

二、Principle of ZJ series roots vacuum pump:

The working principle of roz vacuum pump has the working principle of volumetric pump and the pumping effect of molecular pump. Due to the continuous rotation of the rotor, the exhaust gas is sucked into the space V0 between the lower rotor and the pump shell from the air inlet of the roz vacuum pump, and the V0 space after inspiration is completely closed. With the rotation of the rotor, the enclosed V0 space is connected with the exhaust port, and due to the high gas pressure in the exhaust side, a part of the gas is pushed back, causing the gas pressure in the V0 space to increase suddenly. When the rotor continues to rotate, the original sealed gas in the V0 space along with the recoil gas is discharged to the roz vacuum pump. At this time, the upper rotor is sealed into the V0 volume of gas from the roots of the roots vacuum pump. Because of the continuous operation of the roots vacuum pump, the two rotors continuously form the enclosed space V0 and continuously exhaust the gas out of the enclosed space, thus realizing the purpose of pumping gas.

三、ZJ series roots vacuum pump features:

1. There is a large pumping rate within the wider pressure range. It ACTS as a "accelerator" for the high pumping speed and ultimate vacuum of the pump.

2. There is no friction in the running parts of ZJ series roz vacuum pump. No lubrication, no oil in the pump chamber, and a clean vacuum can be obtained.

3. The vertical flow of gas in the ZJ series roz vacuum pump is conducive to the removal of dust and condensate from the gas.

4. ZJ series roz vacuum pump is completely symmetrical and the precision dynamic balance rotor is stable and reliable.

5. Compact structure, designed with vertical and horizontal exhaust ports, easy to install.

6. The mechanical friction loss is small, so the driving power is small.

7. Easy to maintain and repair, low cost and high life span.

8. Vibration and noise are small.

9. Remove the condensable gas.

10. Eliminate oil leakage and emulsification -- the application of oil seal shaft seal and compound seal structure design.

11. ZJ series roz vacuum pump is safe and reliable, and the ZJP series itself is equipped with overflow valve to provide automatic protection.






Pumping speed(L/s)





Ultimate pressure

1stage piston pump as backing pump


2 stage piston pump as backing pump


Max. allowable diff. pressure(Pa)



Motor rotary speed(RPM)


Suitable motor power(kW)





Flange size











Cooling water consumption(L/h)



Allowable temperature(℃)


Vacuum pump oil


Weight(without motor)(kg)