A device for separating a flowing medium mixture into at least two fractions, comprising rotating means (7) in the form of a rotating assembly of feed channels (6) for rotating the flowing mixture for separating, a feed for the medium mixture (5) for separating connecting to the rotating means, and an outlet connecting to the rotating means for discharging one of the fractions of the separated medium mixture, wherein the medium mixture can display a substantially turbulent flow during separation. Also disclosed is a method for separating a flowing medium mixture.