ZJQSeries

Introduction:
Air cooled roots vacuum pump is based on common vacuum pump, with the addition of bypass gas cooling system. The external cooler make the gas auto recycling to cool down the rotor and casing, and the cooled gas flows into suction cavity from casing two sides, this will avoid overheating of the casing caused by gas compression and make reliable, enduring operation in high differential pressure and high compression ratio, with no influence on pump performance. The pump can be used single or in multi series, or combine with liquid ring pump or common roots pump into units to get high vacuum for various process.

Working principle:
ZJQ series air cooled roots pump structure is as shown in the figure: two rotors (two blades or more) in the pump chamber are installed on a pair of parallel shaft, and driven by two wheel gears with 1:1 transmission ratio and make opposite rotation. The two rotors, rotors and inner surface of the casing remain a certain gap, this is benefit for fast rotation. Different with ZJ series common roots pumps, ZJQ series are designed with a reflux port on the side of the casing, this is used to introduce the cooled gas into pump chamber to cool down rotor, so the rotor temperature will be kept within limits, and ZJQ pumps can stand higher differential pressure (as high as 90kPa) without overheating.

Features:
They can be used alone or in series, or connected with liquid ring pumps.
Vacuum degree reaches 150mbar when it is direct discharged into air
Medium vacuum can be realized by connecting in series or with liquid ring vacuum pump.
Special structure helps to avoid overheating and overloading in high differential pressure and compression ratio.
The dynamic balance test and high precision process machine insure the smooth and quiet running of the product.
The balanced mechanical seal makes better sealing effect for the pump.
The chamber is oil free, so the pump is suitable to extract common or various special gases.
More energy saving compared with other mechanical vacuum pumps.

Main parameters of air cooled roots pump

NOTE:
Motor power and cooler area are decided by differential pressure; different differential pressure accord with different motor and cooler.
The limit pressure in the table indicates the value when the pump is discharged directly into air; when connected with backing pump, its limit value is the same with ZJ series roots pump, this may refer to the limit value of corresponding roots pump unit.
Pump performance curve

Dimension drawing