Vacuum Pumps

Mechanical pumps

The main principle for all mechanical pumps is that they convey, in one way or another, a certain volume of air from the suction side (the vacuum side) to the exhaust side. In that way they create a vacuum. Mechanical pumps usually have an electric motor as power source, but it can also be an internal combustion engine, a hydraulic or a compressed air-driven pump.

Fans AdvantagesDisadvantages
Centrifugal blowerFew moving parts
Large suction volumes
Strong
Low maximum vacuum
Slow start-up and long stop time
High noise level
Regenerative blower Few moving parts
Large suction volumes
Low energy consumption
Low maximum vacuum
Slow start-up and long stop time
High noise level

Displacement pumps

Displacement pumps AdvantagesDisadvantages
Piston pumpRelatively low price High heat emission
Low maximum vacuum
Membrane pumpFew moving parts
Compact
Low price
Small suction volumes
Vane pumpHigh vacuum and flow
Relatively low noise level
Sensitive to contamination
Relatively high price
High service requirements
High heat emission
Roots pumpHigh flow
Low service requirements
High price
High heat emission
High noise level

Compressed air-driven ejector pumps

All ejector pumps are driven with pressurised gas, usually compressed air. The compressed air flows into the ejector pump, where it expands in one or more ejector nozzles. When expanding, the stored energy (pressure and heat) is converted into motive energy. The speed of the compressed air jet increases rapidly, while the pressure and the temperature go down, attracting more air and thereby creating a vacuum on the suction side. Some ejector pumps may also be used to blow air.

Compressed air-driven ejector pumps AdvantagesDisadvantages
Single-stage ejector Low price
No heat emission
Compact
High noise level
Gives either high flow or high
vacuum
Poor efficiency
Multi-stage ejector High efficiency
Low energy consumption
High reliability
Low noise level
No heat emission
COAX® technology High efficiency
Low energy consumption
High reliability
Low noise level
No heat emission
Operates even at low feed
pressure
Integrated features
Modularly built
Easy to supplement and
upgrade later on
Easy to clean