A Heronsbrunnen is named after its inventor Heron of Alexandria named fountain, which seems to work endlessly without outside influence. In fact, water is pumped from a reservoir to a higher reservoir lying, so this fountain is maintained by the interaction of air pressure and the associated container running until the output reservoir is empty. Depending on the size, such a Heronsbrunnen work for hours, made without outside work or energy must be added. However, he is not a perpetuum mobile.
The figure shows the principle of Heronsbrunnens. The water that is collected in the top, open-topped container, flows into the lower container K1 and compresses the air inside above the water level by the pressure of the water column with the height of D. By a further tube of air pressure at the middle vessel K2 passed, which in turn acts on the local water table and the water also suppressed by the leading top -center tube with a final nozzle, creating a fountain. The water of the fountain is collected from the upper tank again, so that a closed circuit is tricked.
At the beginning of the container and the container empty K1 K2 is full. The water level in the tank K1 increases with time at the same volume as it falls in the container K2. The fountain dries up as soon as K2 tank is empty. Neglecting losses due to evaporation or spraying addition there is then all the water in the tank K1.
The potential energy of the water in the top collector is converted into kinetic energy in the jet. The fountain height is neglecting friction losses determined by the ever smaller pressure difference D, so that the height of the fountain over time also decreases.
The necessary potential energy is given by the well initially, that the water must be transported into the container from the container K1 K2, where mechanical work to be done.
Embodiment of a Heronsbrunnens Plexiglas