To shorten the treating time of a whole and to prevent the occurrence of partial loss to a furnace wall by a method wherein through measurement of the furnace wall of each electrode part, respective powers charged to respective electrodes are previously individually set to average the furnace temperatures.
A three-phase AC arc furnace 11 is provided with a furnace body 12 and a furnace cover 13 with which the furnace body 12 is covered. The furnace body 12 and the furnace cover 13 is built from furnace shells 12a and 13a and fire resisting materials 12b and 13b, with which the furnace shells are lined. Three electrodes 21-23 are inserted through the furnace cover 13 in a furnace. Charged powers to the electrodes 21-23 are previously individually set at a control device 61 such that the furnace wall temperatures of electrode parts 21-23 or the treating state of a metallic material in a furnace is averaged. This constitution prevents the occurrence of a cold spot in the arc furnace 11, whereby the treating time of a whole is shortened and a partial wear of a furnace wall is prevented from occurring.
KAMESHIMA TAKATOSHI
KITABAYASHI SHOJI
