ZJ series Roots Vacuum Pumps

Download the brochure of ZJ series(pdf)

Summary

The Roots vacuum pump is also known as the mechanical booster which is a positive displacement type pump. It is one of the special pumps which can reach milddle, high vacuum range. Its work principle is similar to the Root fan. Both of them used a pair of rotors, whose shape looks like 8, to achieve the suction and discharge process. please refer to Work Principle of the Roots Pump.

According to the technics that the plenty of vapor and solvent is required to pump in the mechanical, phamacy areas, we have improved the seal type of the bearing housing and gear box of the ZJ series Roots pump to reduce the emulsification of the pump oil efficiently and make the Roots pump more suitalbe to assemble with the water ring vacuum pump to suction more vapor and solvent.

Main Characteristics of the Roots pump

• It has larger suction capacity in the wider pressure range(1~1*10⁴Pa).

• There is no oil in the pump chamber, so the pollution of the oil vapor is avoided.

• It has less libration and lower noise.

• It has less mechanical attrition and drive power.

• It is easy to repair and mantanance, so it has lower mantanance charges and longer usage life.

• It can pump the coagulated gases.

• It can not be used separately, a fore pump is needed. Under the atmosphere, it is not allowed to start directly until the inlet pressure reaches the definite pressure that obtained by the fore pump. The water ring vacuum pump, the oil ring vacuum pump and oil seal mechanical pump can be used as the fore pump.

The Main Characteristics of the Bozhong Roots pumps

• The seal structure is improved.
  The bearing housing of the Roots pump is normally cooled and lubricated by the lubricant. If the emulsification of the oil occurs, the oil must be replaced with new oil immediately. Otherwise, the rust of the bearings will lead to libration and larger noise of the pump. At the moment, if the wearable bearings is not replaced at once, it will lead to the abrasion of the gear and then the damage of the pump.
  According to the oil emulsification of the Roots pump occurs when it pumps the much vapor and solvent with the water ring vacuum pump, our company improved the seal structure of the pump chamber. We add flexibale seals made from FPM or PTFE material between the chamber and bearing housing to avoid the oil emulsification sufficiently. The seal structure has been validated by many years practice.

• The surface of the chamber of the pump is nickeled.
  The rust of the surface of the rotors and chamber occuring easily when the Roots pump takes out the much vapor and solvent or the pump stops for several days. The rust can lead to the abration of the pump or the pump will be jamed.
  To avoid the above phenomena, our company nickeled all the surface of the rotors and inner chamber of the pump. After nickeling the parts, the wearable and corrosive-proof capacity of the Roots pump is improved much.

• The shape line of the rotors
  The mesh clearance between the rotors is the most important factor which influences the performance of the Roots pump. On the premise that the Roots pump runs steadily, the mesh clearance must be uniformity and least. Because a definite windage between the theoretic and the practice shape line of the Roots pump exist, our engineers revised it many times. Finally, the uniform shape line is achieved. By comparing with the abroad products, the performance of our Roots pump is also the same as them.

• All the casts are founded by the metal model and the resin sands. The surface is very smooth and can be spray-painted directly. So the heat can be given out sufficiently.

• The bearings are all adopted the import products with brand NSK, so the running stability and long life of the Roots pump can be ensured sufficiently.

• All the adopted gears are in their high qualities with at least 6 grade according to the international standard. All the gears are quenched with high frequency and the teeth are machined by the gear miling so that the pump runs steadily and with lower noise.

• The surface of the pump is all spray-painted by the epoxy paint with high quality, which is able to bear the acid, alkali, and high temperature. So the surface won't turn colour for a long time.

Photos of the spare parts: nickeling rotors, end-shield founded by the resin sands, nickeling surface of the casing 1, nickeling surface of the casing2, Roots pump after test