Siphon

A siphon or siphon is a device or a device with which you can decant a liquid from a container on the container rim into a lower reservoir or drain into the open without tipping the container and without benefit of a hole or an outlet below the liquid level has. In this case, the hydrostatic pressure is utilized. To fill the hose and set the flow process in motion, the liquid is mostly sucked by mouth.

The two containers must be connected with a hose or the like. The piece, in which the tube is guided up and down by the same amount again, adds to the pressure differences seen in the global tube not included. In this piece, the gravitational forces of the liquid same mutually exclusive. The additional liquid in the range between upper and lower containers causes a pressure difference, so that the liquid flows due to the negative pressure resulting from the upper to the lower container, thereby overcoming the container rim.

This pressure difference depends only on the length of the excess water column from apart from the difference in pressure of the surrounding air and the decrease of gravity:

Examples

The siphon principle can be applied from a Gärballon among others when pulling off the wine.

It is also applied on a larger scale at the spillway of dams. The easily accessible example of a spillway, which is designed as a siphon weir, you can visit the outlet structure of flood retention basins Treysa goat grove.

The siphon principle in the cup of Tantalus, also Heron cups or Pythagorean cup is also called realized. If you fill it too high, it empties out to the end.

A ( self-made ) jack can be used for flooding as a pump for the Liberation of flooded cellars and areas of mud - water (gravitational pump): For this, a hose is left down in the flooded area, while filled with water, sealed the ends and a end to a deeper place outside the flooded area drawn (sewer or a river ).

Alternatively, tubes are used which have at the top of the structure via an inlet opening. By those the tube construction is filled with mud water or tap water and then sealed at the top.

If you open then inlet and outlet, the flooded area drained. This is the faster, the greater the difference in height between the water surface and the outlet and the larger the hose or pipe radius:

Flow rate in m³ / h = 50,000 x (height difference in mx radius in m) ².

So, for example, promotes a drainage tube with a diameter of 10 cm with a height difference of 1 meter approximately 125 cubic meters of water per hour. However, in a smaller tube (about 1-5 mm ) is not reached the calculated performance of the hose because of resistance. In an even smaller tube (<1 mm ) does not work anymore due to the principle of capillary action.

If no hose with lockable openings is present ( usually ), the beginning of the tube is kept under water and a second filled with tap water ( openings blunt voreinanderdrücken ).

In a simple system, a 90 ° curved pipe, for example, suspended with 10 cm diameter in a water container, while the longer projecting outwardly. Then, a sponge or a ball on a string quickly through the tube to the outlet of the Sly out and pulled the siphon action starts.

Heber also be used instead of pumping stations in sewer construction.