Screw pump different applications and handling fluids with varying characteristics. Each ‘screw pump' operates on the same basic principle of a screw turning to isolate a volume of fluid and convey it. However, the mechanical design of each is different. The primary difference is the number of screws: one, two, three or more. The screw pump was described by Archimedes on the occasion of his visit to Egypt. This suggests that the apparatus was unknown to the Greeks before Hellenistic times. A cuneiform inscription of Assyrian king Sennacherib (704–681 BC) has been interpreted by Stephanie Dalley to describe casting water screws in
Archimedes' screw areas. It was used for draining land that was underneath the sea in the Netherlands and other places in the creation of polders. Archimedes screws are used in sewage treatment plants because they cope well with varying rates of flow and with suspended solids. An auger in a snow blower or grain elevator is essentially an Archimedes screw. Many forms of axial flow pump basically contain an Archimedes screw. The principle is also found in pescalators, which are Archimedes screws designed to lift fish safely from ponds and transport them to another location. This technology is used primarily at fish