US Patent 7841475 Continuously operating machine having magnets

A continuously operating magnetic particle separating machine includes an inlet for receiving a material having magnetic particles mixed therein, an outlet for discharging the material after the magnetic particles have been separated therefrom, a first flow path extending between the inlet and the outlet, a first magnetic element positionable in the first flow path, a second flow path extending between the inlet and the outlet, and a second magnetic element positionable in the second flow path. The separating machine includes a control system including a diverter valve switchable between a first position for directing the material through the first flow path and a second position for directing the material through the second flow path, whereby the switching frequency of the diverter valve is responsive to a concentration of the magnetic particles in the material.