Knitel's InfinityPump

[itanimuLLi]

Here is the animation link it was to big for the thread.
http://www.overunity.com/index.php?action=tpmod;dl=item258

[hansvonlieven]

Yes you can get this thing to work in animation. In the real world you cannot.

Hans von Lieven

[Onevoice]

Hi Hans,

Excellent paper on siphons. Good read, low enough on technical details for a tinker like me to understand without coming off as rude to the reader. I do have a couple of points I'd like to mention though. In the 'Other misconceptions', Figure 2 section, I think you meant to say 'most PM designs' rather than 'must PM designs'. For a paper like this, a quick grammar check can help pick off the correctly spelled wrong words.

The second issue is one of omission. You glossed over how a siphon is started. Typically, this is done by creating a vacuum in the line that is greater than the forces pulling the water down to its natural level. I don't know if the hydrostatic differential plays a big part in this or if its just overcoming gravity, but I think its important for the following reasons.

First, Every aquarist occasionally needs to cleanup an overly dirty tank. anaerobic bacterial action can create large amounts of methane that becomes trapped under the gravel. When siphoning up the muck, these methane (gas) bubbles are caught in the line. So long as the bubbles aren't so long that they violate the integrity of the hydrostatic pressure at the bottom of the siphon, the process will pass them along without a problem. I've wondered whether the atmospheric pressure of the bubbles is lower than or equal to the outside air. My Assumption is that it is lower. The bubbles are in a state of partial vacuum because they are being 'pulled' along by the stable water column below them in the system.

Also, While the Egyptians, and I, both used our mouths to initiate the vacuum required to start our siphons, there are several commercially available 'starters' for people that are unwilling to take a short suck on their fish tank. Various squeeze bottles and such are designed to aid in pumping enough water through the line to start the siphon process. Quite often, these pumps result in a trapped bubble within the siphon that in no way causes the siphon process to become unstable.

I think these are important to the designs we're discussing here because they illustrate what happens at intermediate stages of the pump designs. A piston, Knitel's MP, is essentially the same as the bubbles in the line but with a weight displacement heavier than water rather than lighter and it is possible for a downward piston to siphon even with some air trapped at the top of the chamber so long as it is a hydrostatically sealed environment on the downward stroke.

I've attached an image with two siphons which will also function perfectly. They illustrate the principles that I'm talking about.

PS. I'd really like to read your paper on Buoyancy.

[hansvonlieven]

A vacuum is not required to start a syphon. Admittedly it is one way of doing it, but all that needs to be done is to insure the siphon tube contains no air. Simply filling the siphon tube with liquid, closing off both ends, immersing one end in the tank and holding the other end below the level of liquid in the tank, then opening up the tube will start it.

As to my paper on density, I wrote this in German for another forum and have yet to translate it. When this thread here suddenly stopped I did not do it because there seemed to be no interest.

Hans von Lieven

[Nabo00o]

Great paper on hydraulics and hydrostatics hansoliven!

Siphoning has interested me quite a bit recently, and of course I have tried out the things that dont work.
However I think i know how to make it work, by using gravity....
Wanna know more?

Nab