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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.
Three principal forms exist; In its simplest form (the Archimedes' screw pump or 'water screw'), a single screw rotates in a cylindrical cavity, thereby gravitationally trapping some material on top of a section of the screw as if it was a scoop, and progressively moving the material along the screw's axle until it is discharged at the top.
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 spiral pump, as many low lift pumps, is commonly used for irrigation purposes and for drainage of lands. Based on the same principle as the Archimedean screw, it consists of a rotating tube or plane (screw) to move a liquid. Unlike the Archimedean screw, it can pump while horizontal. The Archimedean screw must be tilted at an angle.
Described by Vitruvius, Archimedes' device may have been an improvement on a screw pump that was used to irrigate the Hanging Gardens of Babylon. [49] [50] The world's first seagoing steamship with a screw propeller was the SS Archimedes, which was launched in 1839 and named in honor of Archimedes and his work on the screw. [51]
3rd century BC – Archimedes published On Floating Bodies describing the general principle for buoyancy and hydrostatics. Archimedes develops Archimedes' screw for water extraction. [1] 2nd century BC – The aqueduct Aqua Tepula and Aqua Marcia aqueducts are completed in Rome. [1] Zhang Heng of Han dynasty designs the first known seismoscope ...
Principle of screw pump (Saugseite = intake, Druckseite = outflow) Screw pumps (fixed displacement) consist of two Archimedes' screws that intermesh and are enclosed within the same chamber. These pumps are used for high flows at relatively low pressure (max 100 bars (10,000 kPa)).
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.