Rotor for magnetically sorting different metals

A magnetic sorter rotor for applying rapidly reversing, high-density magnetic flux fields to mixtures of irregularly shaped pieces of different non-ferrous metal for inducing repulsive forces in the pieces for use in sorting and separating the pieces into predetermined groups, comprising:

• a hollow, generally uniform wall thickness, cylindrical drum formed of a ferrous material and having an outer peripheral surface and a substantially horizontally arranged central axis about which the drum is rotated;
• closely spaced, narrow, permanent magnet rows secured upon the drum outer peripheral surface, with each row having an outer exposed surface, a base surface located upon the drum outer peripheral surface, and elongated opposite side edges;
• with the rows being alternatingly thicker and thinner in dimension taken radially outwardly of the drum outer peripheral surface, so that the outer surface of each thinner row is depressed towards the central axis of the drum relative to the outer surfaces of its adjacent thicker rows;
• the thicker rows being substantially rectangular in cross-section and formed of a plurality of substantially identical permanent magnets arranged end to end;
• the thinner rows formed of a plurality of substantially identical permanent magnets arranged end to end having their sides slightly converging in a direction toward the interior of the drum, so that they are generally trapezoidal in shape to substantially abut the thicker rows enabling the thicker and thinner rows to be bonded to one another and form a continuous peripheral surface providing a substantially continuous magnetic surface about the drum;
• the direction of the polarity of the thicker rows being generally radial relative to the drum, with the outer surface of each thicker row being of the opposite polarity than the polarity of the outer surface of the next adjacent thicker rows;
• and the direction of the polarity of the thinner rows being generally circumferential, that is, extending transversely from side edge to side edge, with the polarities of the side edges being the same as the polarity of their adjacent thicker row exposed outer surfaces;
• whereby a magnetic flux field flows transversely through each thinner row and then radially outwardly through one of its two adjacent thicker rows and over the depressed outer surface of that thinner row to return radially inwardly through its opposite adjacent thicker row, and whereby rotation of the rotor produces a rapidly changing, high flux density magnetic field in an elongated band-like zone located slightly above the rotor and extending generally parallel to the drum central axis for inducing repulsive forces in pieces of different metals which are passed transversely through that zone to assist in sorting the different metal pieces.

A magnetic rotor for applying rapidly reversing, high-density magnetic flux fields to mixtures of irregularly shaped pieces of different non-ferrous metal for inducing eddy currents causing repulsive forces in the pieces for use in separating the pieces into predetermined metal groups, comprising:

• a cylindrical drum having an outer peripheral surface and a substantially horizontally arranged central axis about which the drum is rotated;
• closely spaced, narrow, permanent magnet rows secured upon the drum outer peripheral surface, with each row having an outer exposed surface and a base surface which is located upon the drum outer peripheral surface, and elongated opposite side edges;
• the rows being alternatingly thicker and thinner, measured in a direction radially of the drum, to form pairs of adjacent thicker and thinner rows around the circumference of the drum, and with the rows having exposed outer surfaces so that the outer surfaces of the thinner rows are depressed relative to the outer surfaces of the thicker rows;
• the thicker rows being substantially rectangular in cross-section and formed of a plurality of substantially identical permanent magnets arranged end to end;
• the thinner rows having their sides slightly converging in a direction toward the interior of the drum, so that they are generally trapezoidal in shape to substantially abut the thicker rows enabling the thicker and thinner rows to be bonded to one another and form a continuous peripheral surface about the drum;
• the rows being formed in adjacent pairs with the direction of polarity of the thicker magnets in one row being generally radial of the rotor, and with the directions of polarity of the thinner magnets in the adjacent row of the pair being generally circumferential of the rotor;
• with the polarity at the outer surfaces of the thicker magnets of each row of radially directed polarity being the opposite to the polarity of the outer surface of its next adjacent row of radially directed polarity;
• and with the polarity of each of the sides of the thinner magnets of the rows of circumferentially directed polarity being the same as the polarity of the outer surface of their adjacent magnets of their adjacent rows of circumferentially directed polarity;
• whereby a closed magnet flux path is established between each thinner row and its two adjacent thicker rows, which path extends in a generally circumferential direction through the thinner row and in a generally radially outwardly direction through one of its adjacent thicker rows, then over the exposed outer surface of the thinner row to the opposite thicker row and back through such opposite thicker row, whereby rotation of the drum momentarily positions each of said closed flux paths adjacent a zone containing said mixture of pieces to produce a rapidly alternating, high-density flux field through the zone.