Principle of Water Ring Vacuum Pump

 
The casing of the machine is cylindrical with control disc on either side. An eccentrically located impeller with curved blades rotates within the casing. The liquid (preferably ) introduced is set into rotary motion by the blades, thus forming the water ring concentric with the casing. Cells are formed between the ring and the blades of the impeller which vary in volume from maximum to minimum with each revolution. The conveying medium enters the working chamber through the opening in the lateral control discs and is compressed by the decrease in volume of the cells. It then flows together with the cooling  through discharge opening in the control discs to the delivery port.