Theory and experimental investigation of an improved field boundary model for a single boundary eddy-current separator

The theoretical representation of the magnetic field profile of a single boundary eddy current separator is improved by using a multistep staircase field that follows the measured profile, instead of using a single step. The theory of conductors moving through the staircase field is presented. The results of an experimental investigation of this motion over a wide input velocity range show that the new boundary representation removes much of the high and low velocity discrepancy that exists between theory and experiment when a single step field is used. The reasons for that discrepancy are explained. Emphasis is placed on the existence of a maximum velocity of input of material to the separator, which is much less than previously thought, and will allow more accurate and safer predictions of the device parameter settings necessary for high throughput separations