| 摘要 |
PURPOSE:To heat efficiently a molten metal during pouring by a comparatively small-sized and small-capacity, electrically-energizing device, by flowing a three-phase AC between the upper part of the molten metal flowing pipe of an electrically-conductive and fire-resistant immersion nozzle attached to a tundish, and its immersed bottom end to heat the nozzle by resistance heating, and supplying a single-phase current by removing the bottom electrode during the immersion of nozzle. CONSTITUTION:The bottom end of an alumina-carbon, electrically-conductive and fire-resistant immersion nozzle 2 attached to a tundish 1, is brought into contact with a copper electrode Co provided with a carbon electrode 14, and the upper part of a molten-metla flowing pipe 2 is held between the projections 5 of single-phase electrodes C, C' of the same constitution as that of the nozzle 2. The nozzle 2 is heated by supplying a three-phase AC10 between the three electrodes. The bottom electrode Co is removed by a driving device 12 when the nozzle 2 is immersed, and the nozzle 2 is heated by supplying the single-phase current between C, C' even while the molten metal is poured, to prevent the clogging of nozzle 2 and the temperature drop with time of molten metal during pouring, thereby obtaining an excellent billet. The molten metal during pouring is heated economically by a comparatively small-sized and small-capacity device. |
