GB673265A - Improvements in metallurgical furnaces comprising stirring windings - Google Patents

Abstract

673,265. Electric furnaces; stirring. ALLMANNA S V E N S K A ELEKTRISKA AKTIEBOLAGET. May 16, 1950 [May 24, 1949], No. 12164/50. Class 39(iii) A metallurgical furnace, e.g. an arc furnace, an open hearth furnace or a mixing crucible has on its base a polyphase winding for stirring the contents fed by a current of a frequency of about one cycle per second for producing a movement in a certain direction in the molten content by co-operation between the flux created by the winding and currents induced by the flux, and the direction of the stirring movement is altered by arranging the phases of the winding that the geometrical direction of the distance from one phase to next succeeding it in time can be altered relatively to the furnace. This is effected by rotating the furnace on a vertical axis above a fixed coil, by rotating the coil beneath a stationary furnace, or by changing the connections between the current supply and the coil, especially for a twophase supply. The furnace body 1 is supported by a circular bar 8 and is rotated on rollers 7 by a motor 9. The stirring windings are constructed as described in Specifications 499,437 and 601,073, are fixed in a shell 10 on a non-rotating base 6 and may have iron cores. The non-rotating roof 2 carries electrodes 3. The furnace 1 has a tapping spout 4 and a charging opening 5 and is supported on a tilting base 6 In a modification, the furnace is fixed to the tilting base 6, and the stirring winding and its shell 10 rest on a circular bar supported by rollers 7 so as to rotate beneath the furnace. When current is supplied from one or more commutating A.C. machines, the brush position on one or more machines may be changed.