A liquid ring 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 could be water, essential oil or any additional solvent which can be 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 pressure holds the liquid band against the inner wall structure 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 increases as the impeller rotates. This creates increasing cell quantity on the inlet port side, creating vacuum.
On the discharge port side, the impeller cell volume decreases as the blades move further into the liquid ring. This escalates the pressure until discharge takes place through the discharge port.
A continuous flow of fresh sealing liquid comes to the pump via the sealing-liquid inlet.
Regarding the two-stage liquid band pump, the discharge from 
the 1st stage will not discharge to atmosphere. Rather, the initial stage discharges through the manifold leading to the Liquid-Ring Vacuum Pump second stage as well as through a discharge interface situated in the intermediate plate between your first- and second-stage impellers.