Cyclone separator

PCT No. PCT/SE93/00592 Sec. 371 Date Mar. 16, 1995 Sec. 102(e) Date Mar. 16, 1995 PCT Filed Jun. 29, 1993 PCT Pub. No. WO93/00242 PCT Pub. Date Jan. 6, 1994A cyclone separator for separating substances from a fibre-liquid-suspension, particularly a paper pulp suspension, wherein the separator has a main part (3) which includes an inner conical chamber (4) that has a generally tangentially directed inlet at the wider end (5) of the chamber, and in which the chamber (4) tapers conically downwards. The inner surface of the chamber has a screw-like configuration characterized by a helix. The screw-like inner surface includes a first upper surface or flank (1) facing towards the wider end of the chamber and a second, lower surface or flank (2) facing towards the narrower end (6) of the chamber. The flank (1) defines an angle alpha with the chamber center line and the second flank (2) defines an angle gamma with the first flank (1). The second flank (2) and its extension together with the first flank (1) on the nearest underlying part of the helix or screw-thread define a triangle that has a line which extends through the apex of the nearest underlying part of the helix.