Table of Contents
Magnetic and Electrical Separation
Volume 10 (1999), Issue 1, Pages 45-55
http://dx.doi.org/10.1155/1999/13573

Selection of an Expression for the Hydrodynamic Drag on a Particle in a Magnetic Separator

The National Mining Academy of the Ukraine, 19 Karl Marx Prospect, Dnepropetrovsk 3200027, Ukraine

Received 7 August 1998; Revised 5 January 1999; Accepted 10 February 1999

Copyright © 1999 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The results of a numerical solution of equations of the motion of a paramagnetic particle in the working gap of a magnetic separator for various values of magnetic induction (from 0.2 to 2 T) and the particle diameter (from 10 µm to 1 mm) show that along the particle trajectory various types of flow modes: e.g. laminar, transitional and turbulent can be present. It is also shown that some of the well-known formulae approximating the experimental dependence of the hydrodynamic drag coefficient on Reynolds number Re (the so-called standard hydrodynamic drag curve) as a step-smooth function, do not ensure the condition of continuity of the hydrodynamic drag on the boundaries of the range of values Re for which these formulae were obtained. One of the variants of approximation of the standard hydrodynamic drag curve for the case where along the same trajectory various types of regimes of flow-around a particle are present, is proposed.