| 摘要 |
<p>A DC arc furnace of the type having an arcing electrode and a withdrawable starting electrode for initially forming electrical contact with a charge of metal pieces, and an electric connection for a subsequently formed melt in the furnace, has a DC power source positively connected directly with the starting electrode and the melt connection, and negatively connected with the arcing electrode. When initially charged with solid metal pieces, the starting electrode is contacted with the charge so that an arc is formed between the pieces and the arcing electrode until a melt is formed for contact with the connection for the melt. With both the starting electrode and melt connection directly connected positively with the power source, without intervening control equipment, the current automatically commutates from the starting electrode to the melt connection as the melt forms so as to contact the latter. Thereafter the starting electrode is withdrawn from contact with either the remaining solid pieces or the melt, as the case may be.</p> |
