Abstract: A vortex cleaner for separating fibrous suspensions into fractions, in particular for cleaning papermaking pulp suspensions from impurities as chips, shives, sand grains, metal particles, etc., comprises an elongate vortex chamber, which has a circular cross-section and which over part of its length tapers towards its one axial end. The larger end of this vortex chamber has at least one tangential inlet for the suspension to be treated and an axial accept outlet for a lighter fraction of the treated suspension. The smaller end of the vortex chamber has an axial reject outlet for a heavier fraction of the treated suspension. The tapering part of the vortex chamber has a boundary wall which consists of one or preferably two ledges, which face the larger end of the vortex chamber and extend helically with diminishing diameter towards the smaller end of the vortex chamber, and a sidewall interconnecting the consecutive convolutions of said ledge or ledges.

Abstract: A vortex cleaner for separating a gaseous or liquid suspension, as for instance a paper pulp suspension, into fractions comprises an elongate vortex chamber which has a circular cross-section and tapers gradually, over at least part of its axial length, towards one axial end of the chamber. The larger end of the vortex chamber is provided with a tangential inlet for the suspension to be treated and an axial outlet for a lighter fraction of the treated suspension. The smaller end of the vortex chamber is provided with an axial outlet for a heavier fraction of the treated suspension. The tapering portion of the vortex chamber consists of a plurality of chamber sections, which are disposed one after the other in axial direction and are in direct communication with each other.