Abstract: The rotor of a centrifugal separator includes two axially separated end walls and one surrounding wall situated between the end walls. The end walls and a stack of separation discs within the rotor are maintained axially together by a central fastener. The surrounding wall, which is separate from the two end walls, is movable axially during rotor operation relative to at least one of the end walls. The surrounding wall has an inner diameter at the areas where it seals with the ends walls that is smaller than the portions between those sealing areas.

Abstract: A centrifugal separator having a device for the transformation of kinetic energy of a liquid rotating in a chamber (12) to pressure energy comprising a discharge element (17) for the discharge of liquid out of the chamber. The discharge element (17) has a surface (20) arranged to be so located in the rotating liquid body that liquid flows in a predetermined direction along and in contact with the surface (20). The discharge element (17) forms an outlet channel (19) having an inlet opening (22) located in said surface (20), and limited downstreams by a cross edge (25) from which the outlet channel (19) extends a bit essentially in said predetermined direction. An increased outlet pressure is achieved by the fact that at least two passages (27, 28) are arranged in the discharge element (17) connecting a part each of the outlet channel located at axial ends of the cross edge (25), respectively, to the chamber (12) in such a manner that liquid flows through the passages (27, 28 ).