The BLN/MV vacuum pumps works by means of an auxiliary service líquid (usually water) fed into the pumps at controlled rate. As the impeller spins eccentrically to the housing, the líquid is thrown by centrifugal force to the periphery of the housing. This leaves the blades of the impeller immersed to their root at one point of the periphery and only to their tips at the opposite point. As the blades of the impeller that are totally immersed turn towards the point at which only their tips are immersed, a void is created in the cavities between them. At this point, these cavities coincide with the inlet port of the end-plates and the process air (or gas) is induced into the pump. By the same but reverse sequence the air is forced out of the ported end-plate at the other end of the pump establíshing a regular transfer. The degree of vacuum established depends on the energy imparted to the Iíquid by the impeller speed and the characteristics of the liquid.