What is a Liquid-ring Vacuum Pump?

A liquid ring vacuum pump can compress up to atmospheric pressure using water or the process liquid as the sealing liquid.
Also referred to as a water seal vacuum pump because water is commonly used as the sealing liquid which enables the pump to attain ultimate pressures near the vapor pressure of the sealing liquid.

Exhaust Theory of Liquid-ring Vacuum Pumps

A liquid ring vacuum pump is constructed from a casing having an integral impeller. The casing is filled with the sealing liquid and the impeller starts rotating, thus creating centrifugal force that pushes sealing liquid against the casing wall to form a liquid ring. This results in a series of spaces between the blades on the impeller and the liquid ring which, due to the impeller being mounted eccentrically to the casing, varies as the impeller rotates. This volumetric change is used to cycle through intake, compression, and exhaust.

Osaka Vacuum's Liquid-ring Vacuum Pumps (Water Sealed Vacuum Pumps)

Osaka Vacuum's liquid-ring vacuum pumps are available with various sealing liquids, including water. Users can select the sealing liquid best suited for their application, allowing use in exhaust applications for gases (condensable gases) including water vapors and organic solvents.
Recycling the liquid ring in a closed system minimizes waste liquid.

Additionally, the liquid ring vacuum pump can be used with other pumps to meet a variety of processes. For example, the liquid ring vacuum pump can be used with a Roots pump to attain high exhaust and high vacuum using less energy. (PRL series)
Also, an air ejector can be added to improve the ultimate pressure, and prevent cavitation. (1-stage air ejector: WA series; 2-stage air ejector: WB series)


W30S W50S/WA50S
W80S/WA80S W150S/WA150S
W310S/WA310S/WB310S W630S/WA630S/WB630S