GB772958A - Improvements relating to electromagnetic separating apparatus - Google Patents

Abstract

772,958. Magnetic separators. ELECTROMAGNETS, Ltd. March 31, 1955 [June 15, 1954], No. 17494/54. Class 117 [Also in Group XXXVI] In Figs. 1 and 3, an overband self discharging electromagnetic separator 11 and an electronic magnetic metal detecting device 12 are located above a belt conveyer 10 carrying matter, e.g. coal or flour, which may contain magnetic material. The detecting device, which is on the feed side of the separator, comprises coils 121, oscillator 13 and amplifier 14, and through a relay 15, is caused to influence means 16 which controls the supply of energizing current to the coils of the electromagnets 112 of the separator 11. If no magnetic material is present in the matter on the conveyer as it passes adjacent the detector coils 121, the electromagnets 112 are not energized. Presence of magnetic material, however, causes the electromagnet coils to be momentarily energized with high voltage current, and the resulting high intensity field causes removal of the magnetic material ready for discharge via a shoot 113. In Fig. 4, the separator 11 is as described in Specification 679,277, and in Fig. 5 (not shown), the separator is of the drum or pulley type. In a further modification, Fig. 6; a continuously operating separator 11 of low rating deals with the major magnetic constituents of the matter on the conveyer 'but minor constituents of magnetic material are detected and removed by the concurrent or consecutive operation of detectors 12 and suspended magnet type separators 11a. The coils of the electromagnets 112 need not be completely de-energized in the absence of magnetic material, in which case boosting of the energizing current when magnetic material is present is effected by voltage regulation of the multiple resistance or transformer tap changing type. The apparatus of Fig. 7 includes a non-ferrous material detector 12a so that when such material is detected, a shoot 17 is deflected to the dotted line position and the material is conveyed to an inspection station where the non- ferrous constituent may be removed.