A liquid band vacuum pump is Liquid-Ring Vacuum Pump china simple to operate and is used in a number of applications across various industries. A liquid band pump works with a sealant necessary in its operation. This liquid could be water, essential 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 pressure holds the liquid band against the inner wall of the pumping chamber. Because the impeller is situated eccentric to the pumping chamber, the depth of entry of the blades in to the liquid ring decreases and raises as the impeller rotates. This creates increasing cellular volume on the inlet slot side, creating vacuum.
On the discharge port side, the impeller cell volume decreases as the blades move further into the liquid band. This escalates the pressure until discharge takes place through the discharge slot.
A continuing flow of clean sealing liquid comes to the pump via the sealing-liquid inlet.
In the case of the two-stage liquid ring pump, the discharge from the 1st stage does not discharge to atmosphere. Rather, the initial stage discharges through the manifold leading to the second stage and also through a discharge interface located in the intermediate plate between the first- and second-stage impellers.