A Liquid-Ring Vacuum Pump china liquid band vacuum pump is easy to operate and is utilized in a number of applications across various industries. A liquid ring pump works with a sealant necessary in its procedure. This liquid can be water, essential oil or any other solvent which is rotated by an impeller within the casing of the pump.
As the shaft turns, a liquid band is established by the centrifugal force produced by the rotating impeller. This push holds the liquid ring against the inner wall of the pumping chamber. Since the impeller is located eccentric to the pumping chamber, the depth of access of the blades into the liquid ring reduces and raises as the impeller rotates. This creates increasing cellular quantity on the inlet port side, creating vacuum.
On the discharge slot 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 fresh sealing 
liquid comes to the pump via the sealing-liquid inlet.
Regarding the two-stage liquid ring pump, the discharge from the 1st stage will not discharge to atmosphere. Rather, the 1st stage discharges through the manifold resulting in the second stage as well as through a discharge port located in the intermediate plate between your first- and second-stage impellers.