| 摘要 |
<p>A DC arc furnace having a melt or hearth electrode requiring contact by molten metal, has starting electrodes built into the furnace side wall above the hearth and which are contacted by steel scrap initially charged in the furnace. These starting electrodes are fixedly positioned and are part of the furnace construction and are used to provide electrical contact with the steel scrap pile charge during the start-up or melt-down phase while the usual arcing electrode, via its arc with the scrap, provides enough heat to form enough melt to contact the melt of hearth electrode. Thereafter, the arcing current commutates from the arcing electrode to the melt or hearth electrode via this initially formed melt, permitting a complete melt-down thereafter. Being permanent parts of the furnace construction, the starting electrodes need never be removed from the furnace.</p> |
