The rotary bowl (1) of this centrifugal separator is lined with conical structures divided into sectors (7) separated by angularly offset gaps (9) so as to promote a regular spiral fluid flow therein, which is laminar and enhances separation efficiency significantly: in the case of two-phase or three-phase suspensions, a “cake” is obtained on the side wall (8). A scraper (15) rotating at a slightly different speed may be added to enable simultaneously routing of the solid cake to the outlet and continuous processing.