Abstract: Method for controlling one or more vacuum generators (1) and thereby the vacuum in a vacuum sewage system, in particular controlling one or more liquid ring screw pumps in such system, including beyond the generator/s (1) one or more tubular collectors or suction pipelines (2) connected to the vacuum generator and one or more toilets, urinals, grey water sinks etc (3, 4), connected to the suction pipeline through branch pipelines (6). The rotational speed of the vacuum generator (1) is controlled on the basis of the set vacuum requirement.

Abstract: Screw type liquid ring pump including a pump housing (9) with an inlet part (3) and an outlet part (11) and rotating helical screw rotor (8) inside the housing. The rotor is connected with a shaft (7) as well as a driving unit in the form of motor, preferably an electric motor (2), whereby the pump (20) with the pump housing (9) represents an elongation of the motor (2) with the motor housing thus representing an integrated or one piece unit. The shaft seal (22, 23) is provided wholly or partially in an annular space (24) provided within the rotor (8), whereby one end of the seal rests against an annular part (25) of the screw rotor provided in the annular space (24) between the rotor and the shaft, and its other end is tightly engaged against an inwardly protruding part (21) at the outlet end of the pump.

Abstract: Liquid seal pump of the helical screw type including a pump housing (3) with an inlet (2), an outlet (6), and within the housing provided a helical screw rotor (7) driven by means of a motor (8). The outlet (6) of the pump (3) is provided with a sealing liquid tank (4) for supplying of liquid to the pump and thereby maintaining the liquid seal under idle running of the pump.