| 摘要 |
The object of the invention is to provide a vacuum powered emptying system for drainage tanks at dentist's chairs and the like, having a suitable vacuum level for spot extraction devices at the same time as the emptying of the drainage tanks can be performed in a simple way in spite of the pumping head to the drainage piping being higher than said suitable vacuum level, the entire system being closed inside the public surgery area and all inlet and outlet openings being located outside the surgery premises. This object has been fulfilled, according to the invention, by the maximum fluid volume in each drainage tank (1) and the dimensions of the adherent vertical discharge pipe (5) being adapted to one another and to the vacuum level hv of the vacuum pump (9), which equals the highest suitable vacuum level in the spot extraction devices (2), in such a way that during emptying, the tank content will form a fluid column in the discharge pipe (5) of a height h, said height being so much smaller than the height hv that air will be sucked through said fluid column at such a velocity that the drainage fluid will be disintegrated and transported up to the drainage piping (7) at the height H. |
