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The screw pump is the oldest positive displacement pump. [1] The first records of a water screw, or screw pump, date back to Hellenistic Egypt before the 3rd century BC. [1] [3] The Egyptian screw, used to lift water from the Nile, was composed of tubes wound round a cylinder; as the entire unit rotates, water is lifted within the spiral tube to the higher elevation.
A screw turbine at a small hydro power plant in Goryn, Poland. The Archimedean screw is an ancient invention, attributed to Archimedes of Syracuse (287–212 BC.), and commonly used to raise water from a watercourse for irrigation purposes.
The first type of screw conveyor was the Archimedes' screw, used since ancient times to pump irrigation water. [1] They usually consist of a trough or tube containing either a spiral blade coiled around a shaft, driven at one end and held at the other, or a "shaftless spiral", driven at one end and free at the other. The rate of volume transfer ...
The Archimedes' screw is still in use today for pumping liquids and granulated solids such as coal and grain. The Archimedes' screw described in Roman times by Vitruvius may have been an improvement on a screw pump that was used to irrigate the Hanging Gardens of Babylon, but this is disputed due to a lack of actual evidence. [3] [4] [5]
Archimedes screw: Water is fed into the top of the screw forcing it to rotate. The rotating shaft can then be used to drive an electric generator. A gear box is required, since the rotational speed is very low. The screw is used at low heads (1.5–5 metres) and medium to high flows (1 to 20 m 3 /s). For higher flows, multiple screws are used.
The principle of moving water with a screw has been known since the invention of the Archimedes' screw, named after Archimedes of Syracuse who lived in the 3rd century BC. It was not until the 18th century however, and the invention of the steam engine , that a practical means of delivering effective power to a marine screw propulsion system ...
Other questionable attributions to Archimedes' work include the Latin poem Carmen de ponderibus et mensuris (4th or 5th century), which describes the use of a hydrostatic balance, to solve the problem of the crown, and the 12th-century text Mappae clavicula, which contains instructions on how to perform assaying of metals by calculating their ...
The screw pump is commonly attributed to Archimedes on the occasion of his visit to Egypt, but this tradition may reflect only that the apparatus was unknown to the Greeks before Hellenistic times and introduced in his lifetime by unknown Greek engineers.