Patent ID: 7118521

Claim:
A centrifugal separator including a centrifugal rotor arranged for rotation around a substantially vertical rotational axis (R), the centrifugal rotor having a rotor body, delimiting a separation chamber, and a pumping member, that is arranged to rotate with the rotor body and to extend during the operation of the centrifugal rotor downwardly from the rotor body and into a liquid body, situated under the rotor body, for pumping of liquid from the liquid body into the rotor body, the pumping member having on an outside thereof, a pumping surface facing away from the rotational axis (R), extending mainly rotational-symmetrically around the rotational axis (R) and contacting a free liquid surface on said liquid body in an area extending around the pumping member, the pumping surface on the outside of the pumping member, at least along a part of the axial extension of the pumping member in said area, having a generatrix forming an angle-with the rotational axis (R) such that the pumping member along said part of its axial extension defines increasing diameter from below and upwards, so that upon rotation of the rotor liquid will flow upwards from the free liquid surface on the outside of the pumping member, wherein the rotor delimits a receiving space situated so that it receives liquid that upon rotation of the rotor has been brought to flow upwards from the free liquid surface on the outside of the pumping member, and wherein the pumping member includes a continuous surface extending from the pumping surface into a part of the receiving space of the rotor.