METHOD FOR CONTROLLING ARC OF DC ARC FURNACE OF SUCCESSIVE SCRAP CHARGING TYPE

摘要

PURPOSE: To increase melting rate and the constraint limit of scrap charging speed by a method wherein an arc is deflected against scrap charging position when the scraps are being successively charged, the arc deflecting amount is switched to the conducting route having a ratio of arc deflecting amount to interior furnace radius of at least a predetermined value according to the scrap charging speed and to the conducting route having the ratio of at most the predetermined value when molten metal is heated. ;CONSTITUTION: The circumferential uniformity of a thermal loading on the wall of a furnace is changed according to the relationship between a portion impinging against molten metal of a heated air column having an inclination angle, an amount offset from the furnace center, i.e. an arc deflecting amount L, and an interior furnace radius R. The greater the ratio of L to R, i.e., the arc deflecting amount L is, the larger the thermal loading on the furnace wall in the arc deflecting direction becomes, even in the same arc heating conditions. When the scraps are being successively charged, the arc deflecting amount is switched to the conducting route having a ratio of L to R of at least 0.05 and, when the scrap charge is stopped and molten metal is heated, the arc deflecting amount is switched to the conducting route having a ratio of L to R of at most 0.05. In this way the thermal loading on the furnace wall becomes uniform, thereby suppressing the wear of refractory material 2 on the furnace wall.;COPYRIGHT: (C)1994,JPO&Japio