Archimedes' screw
Archimedes' screw is a machine. It is a type of pump used for raising water up. It is a screw inside a fairly tight-fitting cylinder. With the bottom end in water, the screw lifts water up to the top, where it pours out of a spout. The screw can be turned by hand, or by a windmill, or by an engine. The screw is often used for filling irrigation ditches.
Archimedes wrote about it when he was in Alexandria, Egypt. It is not known for certain whether he did invent it, but it is always attributed to him.[1][2] The Archimedes screw is still much in use all over the world.
There is also a kind of reverse Archimedes' screw. Water poured in on top turns the screw. The turning drives an electric generator, which makes electricity. It is good for rivers with modest water drops ('low heads'). The reverse screw has the same benefits as using the screw for pumping: it can handle very dirty water and widely varying rates of flow, with high efficiency.
Archimedes' Screw Media
Animation showing how Archimedes screws can generate power if they are driven by flowing fluid.
A water pump in Egypt from the 1950s which uses the Archimedes' screw mechanism
Modern Archimedes' screw which have replaced some of the windmills used to drain the polders at Kinderdijk in the Netherlands
Archimedes screw as a form of art by Tony Cragg at 's-Hertogenbosch in the Netherlands
An Archimedes' screw seen on a combine harvester
References
- P. J. Kantert: „Manual for Archimedean Screw Pump“, Hirthammer Verlag 2008, ISBN 978-3-88721-896-6.
- P. J. Kantert: „Praxishandbuch Schneckenpumpe“, Hirthammer Verlag 2008, ISBN 978-3-88721-202-5.
- ↑ Oleson, John Peter 1984. Greek and Roman mechanical water-lifting devices: the history of a technology. Dordrecht: D. Reidel. ISBN 90-277-1693-5
- ↑ Dalley S. & Oleson J.P. 2003. Sennacherib, Archimedes, and the water screw: the context of invention in the ancient world. Technology and Culture 44 (1) 1-26. [1][dead link]