A China Air Compressors liquid ring vacuum pump has an impeller with blades attached to a center hub situated in a cylindrical body but off-set from the center.
In Determine 1 to the proper, you can observe the blades near the top of the pump are nearer to the exterior wall than at the sides and bottom of the pump. You can observe this more obviously in Figure 2.
The impeller sits between two end plates (port plates) which have shaped holes cut into them called ports.
The pump requires a liquid (also called the sealant) to create vacuum the following. Prior to starting the pump, it should be partially filled with the liquid sealant. The liquid can be water (making it a water band pump), oil or a solvent, dependant on the application.