10 and the outlets from the pipe will be described in more detail below a deflaking unit 13 is provided at the transition from the second to the third separation unit fig3 and 4 show preferred configurations of a reject outlet in this case reject outlet 9 u2032 in an enlargement of the section marked with a chain dot line in fig2 according to the configuration shown in fig3 an adjusting ring 12 a u2032 is mounted at the lower end of the rotor section 4 u2032 the adjusting ring can have an adjustable mounting as explained above e g in the shape of an iris diaphragm 14 indicated by the double arrow the outer diameter of the adjusting ring or its segments should preferably have a toothed profile 15 with the adjustable ring 12 a u2032 the axial throughput can be controlled by means of the reject outlet 9 u2032 furthermore in the configuration according to fig3 feed points for dilution water 10 a u2032 10 b u2032 and 10 c u2032 are provided on the housing as well as at rotor sections 4 u2032 and 4 u2033 in the vicinity of the reject outlet 9 u2032 and beneath it the feed point 10 a u2032 is located in the lower delimitation of the rotor segment 4 u2032 of the first separation unit 1 u2032 the feed point 10 b u2032 is placed in the upper section of the rotor segment 4 u2033 of the second separation unit 1 u2033 the feed points 10 a u2032 and 10 b u2032 can be supplied through a pipe 10 see fig2 mounted inside the rotor the feed point 10 c u2032 for example is located.