| 摘要 |
PURPOSE:To improve casting capacity by providing plural coils positioned to face the side faces of a steel ingot and providing bias means for conducting AC currents of different phases to the adjacent coils to apply the rotating magnetic field to the steel ingot in the circumferential direction and for changing the level of the amplitude center of the AC currents. CONSTITUTION:The output bias signals from bias circuits 5, 15 are added via adders 2, 12 to the AC electric signals outputted by function generators 1, 11 to current output devices 3, 13 respectively. More specifically, the level at the amplitude center of the AC electric signals is charged by as much as the bias signal component and the signals subjected to the level change by the addition are inputted to the output devices. The devices 3, 13 amplify the AC currents of the waveforms conforming to the respective input signals and conduct the same to the coils 4, 4', 14, 14' respectively. The good electromagnetic stirring effect is thus provided to the ingot by which the internal quality of the ingot is improved. |
