| 摘要 |
<p>1488877 Direct arc furnace BRITISH STEEL CORP 12 March 1975 [12 March 1974] 11008/74 Addition to 1398881 Heading H5H A direct arc D.C. furnace has a plurality of hearth electrodes 16 of one polarity for contact with the charge, each constituted by charge metal in a local reservoir 16 with a refractoryclad rod of the metal 15 extending therefrom, a plurality of dependent electrodes 2, 3, 4 of the opposite polarity suspended above the charge, and switching means 10 for selectively interconnecting one or more of the hearth electrodes to the D.C. supply. As shown in Fig. 3, one only of the hearth electrodes may be connected to the supply, to direct the arcs to a particular part of the furnace. Fig. 4 (not shown) illustrates the situation when all electrodes in the hearth are connected, with the arcs directed towards the centre of the furnace. Three phase A.C. is converted to D.C. via star-delta connected transformers and full wave (silicon) rectifiers (Fig. 1, not shown).</p> |
