water physics

[lauris]

I must not have been paying as good attention in high school physics class as I thought. What I am trying to do is to link two tanks of water. I was thinking that if I got a siphon going from the upper to the lower, and had the pipe at the level I wanted the water at in the lower tank, once the water came up to the bottom of the siphon pipe, the flow would stop. It didn't. The pipe is 1.5" inside diameter, just a basic u tube from the upper to the lower. I did put a backflow preventer in the assembly, is that the problem? Or did I just not pay close enough attention in class.

[nacra99]

hmmmm physics... eeek.... i think it goes. water will stop flowing when H1*p1*g1 = H2*p2*g2. And since p1=p2 and g1=g2, water will only stop flowing when H1 = H2 ;D

ok ok.. so i was trying to be funny.... please forgive me.

but seriously lauris, the water will only stop flowing when the water level of the lower tank is the same as the water level of the higher tank. So in fact, with your set up, the siphoning will continue until the water level is same in BOTH tanks. The diameter of the pipe or siphon will not make too much a diference.

hope this helps
Cheers
Marc

[ronrca]

;) You just need to redesign the top pipe using overflow boxes to regulate the level in the top tank.

Keep out some of these links:
http://forum.simplydiscus.com//index.php?board=19;action=display;threadid=19439;s tart=msg198094#msg198094

http://www.aka.org/pages/libary/flow_through.html

http://forum.simplydiscus.com//index.php?board=1;action=display;threadid=19771;st art=msg201662#msg201662
;)

[Denny]

Was that a Shop Vac moment for you Lauris? ;D Hope it was at your house lol.

The easiest way is to have the tops of the 2 containers at the same level, but my guess is the heights are not the same. Did you stack them on top of each other like you were talking about?

It is possible to link them at different heights, some examples to look at are animal stock tanks and pet water containers where the animal drinks from the bottom, even when the tank is full, the water stops at a predetermined depth in the drinking area. The other example is a toilet.

[lauris]

I chickened out and put in a shut off valve at the last minute, so i just shut it off when i couldn't will it to stop. They are stock tanks stacked on top of each other, one on a platform over the other. Its just a 1.5" pipe from one to the other. I did put in a small submersible to start a siphon, and a backflow preventer so that the siphon would start and not just pump back in to the top tank. It still works fine, just have to watch it and/or use a water alarm when I am filling the bottom with the top tank.

[mikeos]

Unfortunately you cant do what you want with a syphon, you need an overflow