Without the little tube, the siphon doesn't break: air start 'bubbling' in to the bottom holes as soon as the water level gets down. The main water level keeps dropping and the amount of air getting in to the siphon increases until so much air is sucked in that the siphon wants to break. In stead of breaking, a new water column is formed and the siphon keeps running. The little tube sucks in just enough air so the remaining water column between the outer and inner tube drops (gravity).
@drychalice: If you mean with 'open vent' that the siphon has an air inlet (as with f.ex. toilet siphon vents), this will not work. The whole idea of the siphon is to create a water slot once it starts running so it sucks all the water from the water-basin, without pulling in any air as this would break the siphon. Unless you have an system that works?
I made this animation after having some problems with my first auto-siphon. The small tube tube was to big. I first thought that it was to break the siphon. In fact, the tube must be small enough not to break the water flow. The end of the tube should be higher then the holes in the main tube. It sucks some air but the air coming through the bigger holes in the main tube break the siphon function and the small tube just provides the air to let the water column descend.
Why is there a tube running out of the top to the bottom of the bell? I have seen this kind and ones without it and was just curious as to the difference?
Without the little tube, the siphon doesn't break: air start 'bubbling' in to the bottom holes as soon as the water level gets down. The main water level keeps dropping and the amount of air getting in to the siphon increases until so much air is sucked in that the siphon wants to break. In stead of breaking, a new water column is formed and the siphon keeps running. The little tube sucks in just enough air so the remaining water column between the outer and inner tube drops (gravity).
valschep 2 days ago
Why not have an open vent ?
drychalice 2 weeks ago
@drychalice: If you mean with 'open vent' that the siphon has an air inlet (as with f.ex. toilet siphon vents), this will not work. The whole idea of the siphon is to create a water slot once it starts running so it sucks all the water from the water-basin, without pulling in any air as this would break the siphon. Unless you have an system that works?
valschep 2 weeks ago
great animation. for some reason i just found out about hese. im makig some!
dtp5150 1 month ago
Have fun with it!
I made this animation after having some problems with my first auto-siphon. The small tube tube was to big. I first thought that it was to break the siphon. In fact, the tube must be small enough not to break the water flow. The end of the tube should be higher then the holes in the main tube. It sucks some air but the air coming through the bigger holes in the main tube break the siphon function and the small tube just provides the air to let the water column descend.
valschep 1 month ago