Abstract: A liquid ring machine has one partial working chamber of the liquid ring machine which is separated from the supply of operating liquid and is drained of the operating liquid to the point where the part of the impeller rotating in this partial working chamber does not contact the operating liquid, and this partial chamber is blocked on the suction and/or discharge side. The liquid ring machine is able to be optionally partially switched off, thus allowing an adaptation to the specific process requirements.

Abstract: A multi-stage vacuum pump installation having an oil-lubricated or dry-running mechanical displacement pump located in the atmospheric stage. The oil-lubricated or dry-running pump is preceded on the vacuum side by at least one additional pump which is a side channel compressor pump (or gas ring pump). A side channel compressor pump located upstream of the oil-lubricated or dry-running pump reduces oil consumption and at the same time improves efficiency of the installation.

Abstract: An installation for processing liquids having at least one vaporizer used for the process liquid, a condenser arranged downstream from this vaporizer, and a vacuum pump. Additionally, a gas-ring compressor, positioned in the exhaust pipe between the vaporizer and the condenser, presses the vapors from the process liquid through the condenser. The process liquid is vaporized in the vaporizer under a vacuum and the vapors are carried by an exhaust pipe that is connected to the vaporizer through the condenser to the vacuum pump. Also, the process liquid, which is used as the cooling liquid for the condenser, is heated in the condenser and then recycled to the vaporizer.