Particle capture theory and experiment on an amorphous magnetic ribbon filter

The performance of a parallel stream type high gradient magnetic separation (HGMS) filter using an amorphous magnetic ribbon is analyzed. Consideration is given to the effect of neighboring ribbons and the effect of an elliptic ribbon cross-section on the particle capture process. The main theoretical conclusions are 1) the effects of multiple wires parallel to the flow cannot be neglected in high capture rates of the filter, and 2) multiple wires increase the particle recovery in long channels because the fractional fluid-flow cross-section within which particles are captured increases more than the maximum magnetic force decreases. Some measurements on the removal of fine magnetic particles in three types of suspension are carried out by using an amorphous ribbon filter. The experimental particle recovery agrees well with the theoretical one which is calculated by taking into account the grain size distribution in suspensions and the stage effect of the filter. Therefore our theoretical predictions are useful for analyzing the filtration performance of this type of practical filter.