Dry running claws generate contact free vacuum or compressed air efficiently and economically. This technology is used in claw pumps, claw vacuums and claw compressors among other machines. They offer process-safe and reliable operation at fairly low noise levels. Typical applications can be found in wood processing, wastewater treatment and the packaging and printing industries. They are also commonly used in pneumatic conveying and central vacuum systems.

Claw pumps consists of two rotors. They turn in opposite directions without contact. 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.