The Stokesian Dynamics Method and the Settling behaviour of Particle‐Fibre‐Mixtures

Abstract

AbstractSedimentation of fibres and particles can be observed manifold in industrial application. In waste water treatment, the water is clarified from solid particles and fibres utilizing sedimentation. Some filtration processes use fibres as an aid to improve the filtration quality. Finally, in the paper recycling process, one tries to separate cellulose fibres from inorganic particles used as filling material or in printing colours. For all these applications, it is necessary to understand the hydrodynamic interactions between single particles as well as particle and fibre collectives.In the present paper, the sedimentation behaviour of fibres and particles is considered in detail. Mathematic modelling is used to investigate inter particle influences in detail. In particular, a method called Stokesian Dynamics is used to simulate the settling of fibres and particles. The main challenge of the modelling is the dependence of the direction of each fibre on its sedimentation velocity and the different sizes of the particles in a poly‐modal particle size distribution. Additionally fibres, particles and the fluid are influencing each other in a significant manner and in a long range. Therefore, while calculating the force on a particle, one has to take into account the influences of many particles. (© 2010 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)