DEVELOPMENT OF A METHODOLOGY FOR SETTING OPTIMAL ELECTRICAL MODES OF LADLE-FURNACE UNITS TAKING INTO ACCOUNT THE ARRANGEMENT OF ARGON PURGING EQUIPMENT
The problem of reduction of energy efficiency of ladle-furnace units (LFU) associated with non-optimal formation of the electrical mode due to the absence of accounting for the influence of the arrangement of purging blocks in the bottom of the steel ladle and the intensity of argon purging of the melt when determining the setpoints of the parameters for regulation of the electrical circuit of the LFU is formulated. A methodology for setting optimal asymmetric electrical modes for LFU has been developed, taking into account the influence of the arrangement of argon purging equipment on the stability of arc burning and based on automatic reduction of arc lengths in unstable zones, maintenance of the optimal value of the phase-averaged arc current, achievement of the specified heating intensity coefficient (HIC), and minimization of arc radiation coefficients. The criteria are determined and formulas are proposed for calculating the balance coefficients for the setpoints of the impedances of the secondary electrical circuit of the LFU when forming the modes of short, medium, and long arcs with varying degrees of asymmetry. The results of application of the methodology on two LFUs with ladle capacities of 120 and 180 t with furnace transformers of 25 MVA are presented. An assessment of the achieved technical effect from the application of the new electrical modes is performed.