Siphon (from other Greek. Σίφων “tube; pump”) is a curved tube with elbows of different lengths, through which liquid flows from a vessel with a higher level into a vessel with a lower liquid level. To ensure operability, the siphon must be pre-filled with liquid.
Interesting Facts
The Oxford Dictionary of the 1911 edition stated that the principle of operation of the siphon is not based on gravity, but on atmospheric pressure, which is not entirely true. Atmospheric pressure only maintains the continuity of the jet, preventing it from pouring out of the siphon's knees due to the fact that inside the tube at the upper point of the siphon, pressure forms below atmospheric and water boils. In a vacuum, the jet breaks due to the release of air bubbles from the water. However, for water devoid of dissolved gases, the siphon jet also acts in vacuum due to the internal cohesion of water molecules. The siphon mechanism itself is based on the difference in the weight of the water columns and on the internal cohesion of the liquid [1] .
The maximum height difference at which a siphon with real water (that is, with dissolved gases) at atmospheric pressure is 7 meters [2] .
Notes
- ↑ Ya. I. Perelman , Do You Know Physics , Question 97
- ↑ Ya. I. Perelman , Do you know physics , question 99
Links
- The Straight Dope: How Does A Siphon work? (eng.)
- Pnematics of Hero of Alexandria - Interesting Applications of Siphons