Alfa Laval's Rotary Lobe

Alfa Laval Rotary Lobe Pumps are conventional in design and operation. There are no internal contacting parts in the pump head. The rotors are driven by a gear train providing accurate synchronization or timing of the rotors. The rotors contra-rotate within the pump head carrying fluid through the pump, in the cavities formed between the dwell of the rotor and the interior of the rotor case. In hydraulic terms, the motion of the counter-rotating rotors creates a partial vacuum that allows atmospheric pressure or other external pressures to force fluid into the pump chamber. As the rotors rotate, an expanding cavity is formed and filled with fluid. As the rotors separate, each dwell forms a cavity. The meshing of the rotor causes a diminishing cavity with the fluid being displaced into the outlet port.