Electrostatic separation of particles

An apparatus for electrostatically separating two types of particles from a mixture thereof, which comprises introducing a mixture of a plurality of electrostatically separable particles into the upper end of a free fall zone defined by two identical horizontally spaced rows of spaced elongated cylindrical electrodes positioned with their long axes vertical and with each electrode rotating about its long axis;

• a plurality of elongated cylindrical brushes positioned with their long axes vertical, each said brush rotating about its long axis and with its outer surface in brushing contact with one of said electrodes on a side of said electrode generally opposite to said free fall zone, said brush and said electrode being contacted by said brush rotating in opposite directions with respect to each other, a splitter located at the bottom of said free fall zone to direct one type of separated particle from the remainder of said mixture, electrical means to charge said electrodes, and motor driven means for rotating said electrodes in respective said rows in the same direction and for rotating said brushes contacting said electrodes in respective said rows in a direction opposite thereto.

An apparatus for electrostatically separating a feed fixture of two types of particles which comprises a vertical free fall zone having an upper feed end for receiving mixed particles, and a lower discharge end through which separated particles pass, two horizontally oppositely spaced rows of a plurality of spaced rotating vertical axis elongated cylindrical electrodes on respective facing sides of said free fall zone, said lower discharge end having a splitter coextensive with said discharge end for recovering two separated products each of different types of particles originally in the feed mixture, means for applying an electric charge to said electrodes, a plurality of vertically positioned rotating elongated cylindrical brushes contacting said electrodes for cleaning particles therefrom and removing same from said apparatus, and means for rotating said electrodes and said brushes said brushes are enlarged radially with respect to said electrodes, each said brush engaging two of said electrodes spacedly away from said free fall zone to simultaneously cleaning same.