Screw pumps can rightfully claim to be the oldest pump for the conveyance of liquid since Archimedes invented the original hand operated, inclined, spiraled tube and gave it his name.
Today the Archimedean screw pump has taken its rightful place wherever large quantities of liquid are to be raised in a single stage lift and due to the construction of the pump liquids with large solid materials can be tolerated to an extent not possible with most other types of pump. Liquid delivery varies little with atmospheric pressure variations or a wide range of levels in the sump for a given pump size.
These characteristics have led to the employment of screw pumps in sewage works where they are used for raw sewage and treated effluent lift stations, recycling of humus tank effluent, returning activated sludge and a variety of other applications involving the movement of liquids. Other worthy applications for the screw pump are in water treatment plants, industrial product and waste handling, dairies, paper and pulp plants, storm water pumping, irrigation and land drainage.
As the screw rotates, water that is trapped between the flights, centre tube and trough, is carried up the trough to be discharged over the sill at the head of the upper channel. Since the pump does not increase the kinetic energy of the fluid strong casings are not required to resist bursting forces, nor are accurately shaped casings required to deflect high velocity streams of liquid.
Due to the low operating speeds cavitation does not occur, priming devices are not necessary and the pump may be started without any liquid in the sump as this will travel up the trough as soon as sufficient depth is reached. There is no risk of seizure as the submerged bearing is lubricated by its own system.
MATERIALS OF CONSTRUCTION
The full range of equipment, designed, manufactured and installed by Lektratek Water Technology, can be supplied in a variety of materials to suit all operating and environmental conditions.