Roots Vacuum Pump

Roots Vacuum Pumps

Roots pumps are rotary plunger type pumps where two symmetrically shaped impellors rotate in contrary directions in the pump housing. Because of insufficient friction in suction chamber the roots vacuum pump is certainly capable of working at high speeds. The roots pumps operate at the high speeds certainly quietly due to lack of reciprocating mass which also provides dependable 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 fields where the rough, moderate vacuum and high pumping speeds are required.

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

Single-stage essential oil lubricated rotary vane vacuum pumps (accessible final 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 combination with ejectors (accessible last pressure approx. 1 mbar a).
Roots pumps, in mixture with suitable pre-vacuum pumps, are found in particular when in short evacuation times closed volumes are to be evacuated or constantly big volume streams are to be charged. Where the suction house of the pre-vacuum pumps starts to drop (e.g., by single-stage oil lubricated rotary vane pumps with approx. 10 mbar), a roots pump can be started up as a 2. Stage. The suction real estate of this roots pump can be up to 10 moments bigger as the suction home of the pre-vacuum pump.

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


Recent Posts