A liquid band vacuum pump is simple to operate and is utilized in a number of applications across various industries. A liquid ring pump works together with a sealant necessary in its procedure. This liquid can be water, oil or any additional solvent which is certainly rotated by an impeller within the casing of the pump.
As the shaft turns, a liquid ring is created by the centrifugal force generated by the rotating impeller. This push holds the liquid band against the inner wall of the pumping chamber. Since the impeller is located eccentric to the pumping chamber, the depth of entry of the blades in to the liquid ring reduces and raises as the impeller rotates. This creates increasing cell quantity on the inlet slot side, creating vacuum.
On the discharge slot side, the impeller cell volume decreases as the blades move further in to the liquid ring. This increases the pressure until discharge takes place through the discharge port.
A continuous flow of new sealing liquid comes to the pump via 
the sealing-liquid inlet.
Regarding the Liquid-Ring Vacuum Pump two-stage liquid band pump, the discharge from the 1st stage will not discharge to atmosphere. Rather, the first stage discharges through the manifold leading to the second stage as well as through a discharge port situated in the intermediate plate between your first- and second-stage impellers.