GB485284A - Improvements in and relating to magnetic separators - Google Patents

Abstract

485,284. Magnetic separators. FRANTZ, S. G. Aug. 12, 1936, No. 22185. [Class 72] In a magnetic separator having a feed channel through which a grain stream is adapted to pass longitudinally, the polepieces extend longitudinally of the channel on opposite sides thereof, and have cylindrical pole faces contoured to form a gap which gradually decreases in width and have a cross-sectional area wholly enclosing the cross-section of the channel so that magnetic particles in the stream while being carried along are urged in a direction substantially perpendicular to the stream towards the narrow portion of the gap. The pole faces may be contoured so as to produce an isodynamic or an anadynamic field. The mixture to be treated is fed by a pipe 11, Fig. 1, into inclined tubes 9, each tube being placed between polepieces 12 energized by windings 13, Fig. 2, the gap x between the pole faces being given by the formula x9(R - r) equal to a constant, r being the radius from the axis and R a constant. The lower parts of the tubes are divided by a plate 14 to form constricted tubes 18, 17, which discharge the magnetic and non-magnetic particles into receptacles 16, 15 respectively. The mixture may be fed in dry or flooded with water as shown. The stream passing through the tubes may be rendered turbulent by means of water jets or mechanical stirrers. In another form, Fig. 5, the material is fed into a trough 21 containing water up to the level 22, the trough being situated between polepieces similar to the pieces 12. The non-magnetic particles are conveyed by a screw 23 to the pipe 17 and the magnetic particles are urged by a conveyer 24 into the pipe 18. In another form, Fig. 7, the tubes 9 and the pole faces 12 are of helicoidal form surrounding an axis around which the windings 13 are arranged so that particles descending through the tubes, which decrease in width with decreasing radius are at the same time given a rotary motion round the axis. Dividers 14 are placed in, and near, the bottom of the tubes 9 and divide the magnetic and non- magnetic particles, as in the other form described.