Continuous centrifugal separator

In a continuously renewing separator with a rotating cylindrical wall of the type comprising a helicoidal winding with closely adjacent turns of an endless belt which is looped about itself so as to unwind slowly at one end and rewind at the other end while advancing axially at the same time as it is drawn into continuous rotation at a greater speed than the axial advancement, the belt being disposed for this purpose in a rotating first cage turning at the greater speed and comprising on the one hand a device for supporting and guiding the cylindrical wall having adjoining turns and including progressive unwinding and rewinding guides located fixedly in said cage, with a slow and continuous drive means for moving the belt in relation to said cage, the improvement wherein said supporting and guiding device, as well as said drive means are constituted at the same time by a second cylindrical cage coaxial with the first cage and comprising equidistant bars which are integral with two continuous terminal drumheads and which project inside said drumheads, and wherein said belt comprises exterior notches cooperating with the projecting portion of said bars to insure engagement, said second cage being driven at a speed which is slightly different from that of the first cage.