Roots Vacuum Pumps

Roots pumps are rotary plunger type pumps where two symmetrically shaped impellors rotate in reverse directions in the pump housing. Due to lack of friction in suction chamber the roots vacuum pump is certainly capable of working at high speeds. The roots pumps operate at the high speeds completely quietly due to insufficient reciprocating mass which also provides reliable dynamic balancing. As fore vacuum pumps can be utilized rotary vane, rotary piston, screw and liquid band pumps. This types of mixed pumps can be utilized in all areas where the rough, moderate vacuum and high pumping speeds are needed.

Roots pumps are dry-running vacuum pumps and can pump high volumes. In blower procedure you can reach vacuum to approx. 0.5 bar a (as an individual aggregate). In the execution as a high-vacuum blower vacuums are reached up to 10-3 mbar a, but just in combination with the right pre-vacuum pump. As pre-vacuum pumps may be used, for example:

Single-stage oil lubricated rotary vane vacuum pumps (accessible last pressure approx. 10-2 mbar a)
Two-stage oil lubricated rotary vane vacuum pumps (accessible final pressure approx. 10-3 mbar a)
Liquid ring vacuum pumps, if necessary in mixture with ejectors (accessible final pressure approx. 1 mbar a).
Roots pumps, in mixture with suitable pre-vacuum pumps, are used in particular when in a nutshell evacuation situations closed volumes should be evacuated or constantly big quantity streams are to be charged. Where in fact the suction real estate of the pre-vacuum pumps starts to drop (e.g., by single-stage essential oil lubricated rotary vane pumps with approx. 10 mbar), a roots pump can be switched on as a 2. Stage. The suction property of this roots pump could be up to 10 moments bigger as the suction property of the pre-vacuum pump.

In a Roots vacuum pump, an inlet interface is located at a position n spaced by a positive displacement angle of 120° in a single direction from a center of each rotational axis relative to an imaginary line m connecting rotor axes. An outlet interface is located at a posture o opposite to the inlet interface in accordance with the line. An air feed port is produced at a posture t on a casing wall structure acquired by returning by 90° from the positioning o to the inlet slot side to ensure that two closed areas are described by adjacent rotor lobes and a casing internal wall at both slot sides immediately after atmosphere suction respectively. The casing has discharge grooves within an section of the inner wall structure so as to communicate with the outlet port. The region ranges from the positioning o to a position u acquired by returning by 45° from the position o to the inlet port aspect. The discharge grooves possess a total volume Air Vacuum Pump china ranging from 2% to 5% of a volume of one of the closed spaces.