User:Celephicus/sandbox

The concentric or annular siphon is a rarer embodiment of the Siphon which has the discharge tube seperate from the inlet tube, with the opening of the outlet within the inlet tube. It has the obvious advantages of taking up less space and of being able to be constructed with straight tubes and standard fittings, with no need for forming a U in the tube.

The concentric siphon was first described by Hero of Alexandria as proposition 2 in the Pneumatics. He notes corectly that it's means of operation is identical to the more familiar U shaped siphon.

It was used extensively in toilet cisterns as a means of delivering a bulk disharge of water to flush a toilet etc, this use persisting to the present. It is also used in wastewater treatment systems.

A minor use is in the Soxhlet extractor, where a concentric syphon is noted in advertising material as being more robust and having a lower volume than a U syphon.

M