An unusual syphoning observation

[Egon]

Naw, it concerns siphoning!

 

[alchemysa]

Naw, it concerns siphoning!

Egon. Picture this...
1. A large plastic barrel, filled with water, is standing on the ground.
2. One end of a garden hose is in the barrel, resting on the bottom. The other end of the hose is sitting on the lawn about 30 feet away. The lawn slopes very slightly upwards so that the far end of the hose is about 10" above the end thats sitting in the bottom of the barrel.
3. As you know, no water will flow until someone gets a syphoning action going by sucking on the hose or reverse filling it with water.

So far its all totally ordinary. Once the syphoning has been started, the barrel will slowly empty until the water level in the barrel is level with the end of the hose that 30 feet away. (It took about 30 mins). That all proceeded as expected. After 30 mins the flow stopped. But what surprised me was that when the rain refilled the barrel a few days later, the syphon reactivated itself.

If you draw a pic, or think hard about it, its kind of 'bleedin obvious' that its going to do this. Its just simple hydraulics. But its not something I recall ever actually seeing in action before so it intrigued me. But then again I live in 'the driest state on the driest continent on earth' so I don't get to play with water much...

 

[MikeD74T]

alchemysa, I have a 2 level basement with 24" height difference. The lower level is closer to the water table & has a sump with a pump. The higher level has a sump at the opposite end of the house-no pump. On the occasions when I get water in the upper sump I drag out the garden hose & set up the exact senario you described. I adjust to keep the water 4-6" below the floor in the upper sump but it will go down to only an 8" drop & still restart. Sometimes the flow is as little as a fast drip. MikeD74T

 

[alchemysa]

alchemysa, I have a 2 level basement with 24" height difference. The lower level is closer to the water table & has a sump with a pump. The higher level has a sump at the opposite end of the house-no pump. On the occasions when I get water in the upper sump I drag out the garden hose & set up the exact senario you described. I adjust to keep the water 4-6" below the floor in the upper sump but it will go down to only an 8" drop & still restart. Sometimes the flow is as little as a fast drip. MikeD74T

Nice stuff. Good to see its got some practical value. I like Ronmar's self starting syphon too.