| 摘要 |
1,238,080. Electroslag furnaces. LEYBOLDHERAEUS VERWALTUNG G.m.b.H. 17 Oct., 1969 [30 Nov., 1968], No. 51210/69. Heading H5H. [Also in Division H2] In order to prevent the molten bath 6 being rotated by the rotating magnetic field generated by the consumable electrodes 3, 4, 5 of a three phase electroslag furnace, the direction of rotation of the magnetic field is periodically reversed. This permits the lighter slag 7 to rotate and mix, but provided the reversal period is short enough prevents the heavier bath 6 from rotating. As shown contacts 13, 14 periodically reverse the phase connections of the primary side of tapped transformer 8 under the action of a timer 16. The switch 13, 14, 16 could be replaced by thyristors or ignitrons on the secondary side of the transformer. Preferably, however, the thyristors or ignitrons are inserted between two step-down transformers, the first transforming a voltage of 15,000 volts to 750 and the second a voltage of 750 volts to 100. |
