Fiber Separation in Hydrocyclones, 2002 Fall Technical Conference

Hydrocyclones are used in the pulp and paper industry to eliminate undesirable particles as well as for fiber fractionation. In this paper, the flow field and fractionation characteristics of two typical hydrocyclones are simulated by numerical techniques. The Reynolds-averaged Navier Stokes equations are solved in a three– dimensional curvilinear coordinate system. The Launder correction is used to model the turbulence in the highly swirling flow. The model is coupled with a Lagrangian tracking of solid particles representing the fibers. The fiber model allows for the motion in three dimensions. Fibers are represented by a series of connected ellipsoids which allows for the simulation of flexible fibers. Interaction with the wall is implemented. The numerical results are compared to experimental and other numerical results for two hydrocyclone designs. The influence on separation efficiency of fiber properties such as fiber density, diameter, length and flexibility is investigated.