Abstract: In a liquid ring compressor or vacuum pump with a liquid cooled electric motor and in a liquid separator disposed in housings which are connected to each other without piping and are subdivided into chambers by partitions, the compressor or pump housing forms, together with the motor housing, a first housing block and, in a second housing block, which is connected to the first via internal canals, a heat exchanger and the liquid separator are arranged with the two prismatic housing blocks immediately adjacent and sealed to each other on one side. The inlets and outlets for the liquid to be pumped and the cooling liquid are distributed over both housing blocks to provide a closed circuit for the operating liquid and for a continuous external supply of cooling liquid.

Abstract: A liquid ring compressor including a separate gas input opening disposed in the control disc of the compressor near the delivery space of the compressor impeller between the suction and the output openings of the control disc. The improvement of the invention comprises the gas input opening comprising a calibrated gas input opening, and the compressor including means for coupling the opening to the compression space of the liquid ring compressor for continuously feeding a pressure-increasing gas ballast to the delivery space of the compressor through the calibrated opening. The pressure increase of the gas pumped by the impeller ahead of the output openings of the control disc in the direction of rotation of the impeller is thereby reduced.

Abstract: In a liquid ring compressor with a liquid separator which has a liquid take-off point in its housing which is fed by the liquid ring co-rotating with the impeller and connected through connecting lines outside the housing to internal auxiliary liquid circuits, a liquid jet pump is installed in the connecting line and supplied with operating fluid from the liquid take-off point and is used to return liquid which is separated from the compressed gas at least during the start up of the compressor.