Dry self suction type pump arrangement, especially sewer pump, has vacuum pump turned on or off if level of liquid is detected as passing one of two threshold values

摘要

A control mechanism (11, 40, 41) connects the pump arrangement via e.g. a signal wire (33) to a sensor device (10) for the level of liquid (V) inside a chamber (5), and this mechanism is used to turn on the vacuum pump (2) if the level of liquid drops below a threshold value, or it will turn off the vacuum pump if the level of liquid exceeds a threshold value which is higher than or equal to the first value. The pump arrangement comprises a main pump (1) for pumping a liquid, a vacuum pump, at least one drive mechanism (3) for the main pump and/or vacuum pump, a chamber for liquid and gas, and a sensor device for the level of liquid inside the chamber. The bottom side (6) of the chamber is in fluid communication with the suction side (7) of the main pump. The top side (8) of the chamber is in fluid communication with the suction side of the vacuum pump via a tube (9).