A separator for separating a flowable suspension in a centrifugal field into at least two flowable phases of different density. The separator includes a housing, which is stationary during operation and is designed as a tank having at least three openings. The three openings include an inlet for an inflowing suspension and two outlets vertically spaced apart from each other for flowable phases of different density. Annular spaces of the housing are associated with the two outlets. A rotatable drum is arranged within the housing and has a vertical axis of rotation. The drum has three openings, corresponding to the openings of the housing. A multi-part support and drive device, which keeps the drum suspended within the housing, is supported and is set into rotation. An air gap is formed vertically between the two outlets and annular spaces of the housing during operation. The air gap is not filled with one of the outflowing phases during operation when the drum is rotating.