Project Description

Claw Vacuum Pumps And Compressors


The C-Series dry claw vacuum pumps and claw air compressors of Elmo Rietschle generate contact-free vacuum or compressed air efficiently and economically. This is possible because of the principle of internal compression in the rotary claw design. The gas is pre-compressed within the compressing chamber and is then discharged.

The Elmo Rietschle dry claw pumps offer significant energy saving and high efficiency compared to the traditional rotary lobe blower designs without internal compression.

Our innovative claw technology

The claws of the C-Series feature an optimized, high precision shape and roll together without contact, synchronised by a precision gear set. The compression is achieved dry and wear free. Special seals separate the compression chamber and gearbox. The claw rotors control the transportation of the medium by opening and closing the inlet and outlet channels. Thus no sealing fluid within the compression chamber is needed.

Explosion proof versions with reduced leakage are available as well as ATEX compliant vacuum pumps and compressors.

Request for Quotation

Operating Principle of the claw vacuum pump and compressor

The claw vacuum pumps and claw compressors of the C-Series are based on a static compression system. In contrast to rotary lobes, compression happens internally by volume contraction.

A claw pump consists of two rotors. They turn in opposite directions in a compressor housing without contact observing very tight clearances. They are synchronised via a precision gear. As the claw moves over the suction connection and the axial suction channel inlet the gas is sucked into the compression chamber.

As the rotors revolve, the gas moves from the suction side to the pressure side. Then it is compressed by the reduction of the volume between the rotors until the lower rotor uncovers the discharge channel. This “internal compression” leads to high differential pressures at efficiencies of more than 60 %.

Afterwards the pre-compressed gas is discharged via the pressure connection. To remove the heat generated by the compression process, cooling air is sucked in between the compression housing and a silencing cover before it leaves the pump.

Air Map

Highly Energy Efficient Design

The use of IE3 motors and optimized air flow geometry decisively reduce your energy consumption and consequently life cycle costs – as does the flexibility offered by the use of variable speed drives.

Variable Speed for Maximum Control of Suction or Pressure

Our integrated frequency converters ensure energy-efficient operation that not only meets legal requirements but also lowers operating costs.

Long Service Life with a low cost of ownership

Service and/or change of gear oil is due after 20,000 operating hours only – depending on the application. This very long service interval translates into many hours of uptime with minimum interruption and low service costs.

ProCoat to Resist Corrosion and Extend Life Time

Our patented available with the solid dry film coating ProCoat that offers excellent corrosion protection and is ideal for moist applications like drying processes etc. It also repels dust and dirt and provides better resistance against unwanted material entry.

Low Ultimate Vacuum for claw sizes 60 to 150

In the new low ultimate vacuum (LUV) version, our small pumps 60, 100 and 150 m³/h are now capable of supporting packaging and degassing processes, where low ultimate vacuum is needed.

Wide spectrum of performance

With the C-VLR claw vacuum pumps and C-DLR claw compressors the following ultimate pressures are attainable during continuous operation: vacuum up to 50 mbar (abs.) and pressure up to 2.2 bar. Combination pressure-vacuum pumps provide underpressure up to - 0.6 bar and overpressure up to + 1.0 bar.

Compact Design for Best Use of Available Space

The design with the smallest footprint on the market for claw pumps and compressors also gives easy access to all components of the machine – easy to service and inspect.

Noise Levels are 50 % Lower

Sound engineering has enabled us to reduce the noise level by more than 50 % compared to traditional claw pumps: the VLR 501 for example comes in at only 78 dB(A) for 400 mbar.