Centrifugal separator arranged for discharge of a separated product with a predetermined concentration

Centrifugal separator comprising a rotor which forms a separation chamber (5) with an inlet (27) for a mixture of components to be separated, with a first outlet (26) for a separated sludge impoverished component and with a second outlet (11) with flow restricting means (12) for a separated sludge enriched component means being arranged for recirculation of part of the separated sludge enriched component having flowed through said flow restricting means (12) for renewed through-flow thereof, which recirculation means form one or more recirculation passages (16) arranged for such a flow of the sludge enriched component that the recirculation decreases upon increasing viscosity and increases upon decreasing viscosity of the component, characterized by

• means (9) in the rotor forming a reception chamber (10) for separated sludge enriched component, which reception chamber (10) communicates with the separation chamber (5) through the said second outlet (11) thereof,
• means (21) arranged to remove separated sludge enriched component from the reception chamber (10) for maintaining a liquid level therein so low that a flow of sludge enriched component is obtained from the separation chamber (5) to the reception chamber (10),
• means (13) in the rotor forming a recirculation chamber (14) from which said recirculation passage or passages (16) start,
• means (22) arranged to transfer sludge enriched component from the reception chamber (10) to the recirculation chamber (14), and
• means (15) arranged to maintain a liquid surface at a predetermined level in the recirculation chamber (14) close enough to the rotor axis for the obtainment of a flow of sludge enriched component from the recirculation chamber (14) and through the recirculation passage or passages (16).