Liquid Ring Vacuum Pumps

Since compression takes place inside the liquid ring the process is nearly isothermal; the gas does not overheat and vapour within it can condense. In wet applications such as drying, distillation, filtration and vacuum conveying this is a clear advantage over oil-sealed vane pumps. In return, the attainable vacuum is limited by the vapour pressure of the service liquid at its temperature — around 33 mbar with 15 °C service water.

Units in our catalog offer suction capacities from 10 m³/h to 3,600 m³/h with motor ratings of 0.75–90 kW. Single-stage, two-stage and monobloc constructions are available; the operating range is 33–1013 mbar absolute, dropping to 1–5 mbar on a two-stage booster system. The maximum permitted differential pressure is 1.1 bar, with gas temperature limits of 100 °C for saturated air and 200 °C for dry air. Noise level is in the 66–85 ±3 dB(A) range.

Oil-circulated units eliminate water consumption and scaling, operating down to 10 mbar absolute. For which vacuum technology is right for which process, see our vacuum pump selection guide.