Rotary Twin Lobe Blowers Compressors follow the well established principle of the roots-type machine.Operation is both simple and effective. Two 8-shaped Rotors Impellers, mounted on parallel shafts andcontained within casing rotate in opposite directions. The Shape of the impellers is such that a smallaccurately gauged clearance is maintained at all times between the impellers and casing. As they rotate, air is drawn in to the space between the impellers and the casing, where it is trapped as the tip of theimpellers passes the edge of the inlet opening.