Editing Archimedes' screw (section)

== Variants ==
{{main|Screw conveyor}}
[[File:Mähdrescher Schnecke.jpg|thumb|An Archimedes' screw seen on a [[combine harvester]]]]
A screw conveyor is a similar device which transports bulk materials such as powders and [[cereal|cereal grains]]. It is contained within a tube and turned by a motor to deliver material from one end of the conveyor to the other and particularly suitable for transport of granular materials such as plastic granules used in injection moulding. It may also be used to transport liquids. In industrial control applications, the conveyor may be used as a [[rotary feeder]] or [[variable rate feeder]] to deliver a measured rate or quantity of material into a process.

A variant of the Archimedes screw can also be found in some [[Injection moulding|injection moulding machines]], [[die casting]] machines and extrusion of plastics, which employ a screw of decreasing [[pitch (screw)|pitch]] to compress and melt the material. It is also used in a rotary-screw [[air compressor]]. On a much larger scale, Archimedes's screws of decreasing pitch are used for the [[compactor|compaction]] of waste material.

=== Reverse action ===
{{main|Screw turbine}}
If water is fed into the top of an Archimedes screw, it will force the screw to rotate. The rotating shaft can then be used to drive an electric generator. Such an installation has the same benefits as using the screw for pumping: the ability to handle very dirty water and widely varying rates of flow at high efficiency. [[Settle Hydro]] and [[Torrs Hydro, New Mills|Torrs Hydro]] are two reverse screw [[micro hydro]] schemes operating in England. The screw works well as a generator at [[Low head hydro power|low head]]s, commonly found in English rivers, including the [[Thames]], powering [[Windsor Castle]].<ref name=bgTham1>BBC. [https://www.bbc.com/news/uk-england-berkshire-16276225 "Windsor Castle water turbine installed on River Thames"] ''[[bbc.com]]'', 20 September 2011. Retrieved: 19 October 2017.</ref>