Air-cooled Roots Vacuum Pump

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.

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, which can achieve high speed operation. Different with common roots pumps, the air-cooled roots vacuum pump are designed with a reflux port on the side of the casing,which used to introduce the cooled gas into pump chamber to cool down rotors, so the rotors’ temperature will be kept within specified range, therefor, the air-cooled roots vacuum pumps can withstand higher differential pressure (as high as 90kPa) without overheating, and the single pump can achieves an ultimate pressure of approximately 130 hPa.

Features:

1. Used alone or in series, or connected with liquid ring pumps
2. Discharged directly without any waste water;
3. Work under high pressure, can appropriately reduce the fore pump to achieve energy-saving effect;
4. Effectively solved the problem of overloading and overheating which caused by the D/P of the common roots vacuum pump and the different vacuum degree of fore-pump.
5. The dynamic seal of the spindle transmission torque is static seal (ie no skeleton oil seal and mechanical seal), realize Zero-leakage transmission of power.
6. No mechanical contact friction noise, avoid high frequency vibration to transmit power to realize the smooth operation of roots vacuum pump.
7. Compared with rigid coupling, there is no impact when starting, and it is convenient for installation, disassembly, debugging and maintenance.
8. Isolation sleeve static seal instead of rotating shaft motive seal which can thoroughly eliminate the vacuum problems such as vacuum leakage and oil leakage due to shaft seal wear and achieve long-term sealing.
9. No lubrication, no media and lubricant pollution, purification environment.
10. Sealing performance is independent of shaft speed.

Model	Max. speed (L/s)	Ultimate pressure (Pa)	Rotate speed (r/min)	Inlet port diameter (mm)	Motor power (kW)
ZJQ-30	30	2 x 104	3000	63	0.75~5.5
ZJQ-70	70	2 x 104	3000	80	1.1~11
ZJQ-150	150	1.6 x 104	3000	100	3~15
ZJQ-300	300	1.6 x 104	1500	160	4~30
ZJQ-600	600	1.6 x 104	1500	200	7.5~55
ZJQ-1200	1200	1.6 x 104	1500	250	11~132
ZJQ-1800	1800	1.3 x 104	1500	320	15~200
ZJQ-2500	2500	1.3 x 104	1000	400	18.5~250
ZJQ-3750	3750	1.3 x 104	1500	400	30~355
ZJQ-5000	5000	1.3 x 104	1000	500	45~375
ZJQ-12000	12000	–	1000	500	75~280

Working principle