Design

The screwpump is using static compression as design principle. The screw vacuumpump consists of two screws. One of it with righthand thread and the other with a left hand threat. Both screws turn in the compression housing without frction, with very tight clearances. They are synchronizedvia a precision gear. The compression housing and the special shape of the screws form the compression chambers. Due to the opposite rotation of both screws the chamber connected with the suction port is enlarged and the gas is being sucked into the compression chamber. There is no lubrication required in the compression chamber. The screws are made of ductil iron.
The chamber moves axially from the suction to the discharge side. The mass of the gas is increasing due to the backflow from the discharge. At the discharge side, the chamber is moved against the axial housing wall and the volume is reduced until the front surface of the screw opens the pressure channel and the pre-compressed gas is discharged through the pressure duct to atmosphere.
Cooling is achieved by means of a double wall waterjacket of the housing. The sealing is designed by means of two glidering seals at the driveside and a ptfe lipseal at the nondrive side. The bearing at the drive side is fixed with a twin ballbearing. At the non drive side the screw expands and the bearing is designed with rollerbearings.

Applications

The dryrunning screw vacuumpump has its major advantages by compressing wet gases without contamination of operating fluid of the vacuumpump. The ambient temperature should be within 5 to 40 °C. Suction temperature should not exceed 40 °C. If you exceed these temperatures, please contact the manufacturer to avoid failures of the screw!
Installations higher than 1000 m above sealevel are causing reduction of capacity which have to be calculated by the manufacturer. The standard version can not be used in ex-proof applications. For those installations, we have special designed versions with ATEX-certificat. Specific protection has to be forseen to protect the enviroment of explosion!