Patent ID: 7998051

Claim:
A centrifugal separator comprising: a first separator part; a second separator part, which comprises a centrifuge rotor, wherein at least the second separator part is arranged to rotate during an operation state about an axis (x) of rotation at a determined speed in such a way that the first separator part and the second separator part rotate in relation to each other, and to be non-rotating during a rest state; a space, which is provided in connection to the first separator part and the second separator part and which is arranged to house during the operation state a rotating liquid body containing a medium; a mechanical sealing device, which is provided at the space for sealing the space; the mechanical sealing device including a first sealing element, which is provided on the first separator part and has a first contact surface, and a second sealing element, which is provided on the second separator part and has a second contact surface which is parallel to the first contact surface; the mechanical sealing device being designed in such away that the rotating liquid body during the operation state acts on one of the first sealing element and the second sealing element and displaces the same axially in such a way that the first contact surface and the second contact surface are pressed against each other with an abutment force; and wherein the mechanical sealing device comprises a pre-tensioning element which is arranged to exert a pre-tensioning force on the axially displaceable sealing element, which pre-tensioning force acts to displace the first contact surface and the second contact surface from each other that the pre-tensioning force is so large that a gap is formed between the first contact surface and the second contact surface in the rest state, and that the gap is dimensioned in such a way that it forms a throttling.