| 摘要 |
<p>A device for liquid pumping comprises a pump chamber (21) arranged to receive a subportion of the liquid to be pumped. The pump chamber is provided with means for cyclic variation of the pressure in the pump chamber between an overpressure and a depression with regard to the pressure in the chamber (17) where the main portion of the liquid is. The pump chamber (21) is further provided with an input opening (22) and an output opening (23). The input opening (22) has a substantially lower flow resistance in the direction into the pump chamber (21) than in the opposite direction, and the output opening (23) has a substantially lower flow resistance in the direction out of the pump chamber than in the opposite direction, so that with a depression in the pump chamber a larger liquid quantity is sucked into the pump chamber through the input opening (22) than through the output opening (23) and that with an overpressure in the pump chamber a larger liquid quantity is forced out through the ouput opening (23) than through the input opening (22). Due to this fact a net liquid quantity can be sucked in through the input opening and forced out through the output opening. The device makes it possible to pump many types of liquids, for example molten metal, without the use of movable valves.</p> |
