Quote Originally Posted by Menehune
Could this vacuum idea work?

The jar could be any sealed rigid container, that leaks (red arrow) causing a vacuum, which would be replaced by the feed (green arrow).
Newbie here! Thought I would comment on this. As illustrated I can't see how it will work unless an additional supply of vacuum is supplied.

The water height in the closed container is less than the height of the water in the green tube. The container water height would have to produce enough negative pressure (vacuum) in the vessel when the vessel empties to overcome the static pressure in the green tube which it can't in this case. These pressures are directly related to height, temperature and densities of the liquid and not volume. By increasing the height of the closed container you also increase the height of the static pressure which has to be overcome. I can't think of a way other than additional vacuum that would do this but nice thought!