Archimedian screw pumps The archimedian screw pump concept is over 2.000 years old. In the early years the archimedian screw pump was used for irrigation. They used horses and people to power the pump. Nowadays the pump is still used, allthough rarely.
The rotor of the pump is in the form of a thin helical screw. The number of threads on the screw varies from 1 to 3. The rigid screw usually has an angle of 30°. The lift obtained is appoximately half the length of the screw. The lift heads are up to 10 meters and the speed range is from 20 to 80 rpm. An increase in the nominal flow within the pump can be obtained by increasing the rotor diameter and reducing the speed.
A screw shaped spindle rotates centrally within the casing bore. A seal plate rotates on an axis tangential to the spindle rotation and has notches which engage with the flanks of the screw. when the spindle rotates, it drives the seal plate, creating the necessary separation between suction and discharge.