Electric Arc Length-Voltage and Conductivity Characteristics in a Pilot-Scale AC Electric Arc Furnace

The heat transfer processes and the molten metal bath kinetics of the electric arc furnace are governed by the changes in the arc length and voltage. Thus, information on the electric arc behavior with respect to the voltage is important for accurate computation of the furnace processes and adjustment of the industrial furnace parameters. In this work, the length-voltage characteristics of electric arcs have been studied in a pilot-scale AC electric arc furnace with image analysis, electrical data from the furnace, and slag composition. The arc length was determined with image analysis and the relation between the arc length and voltage from test data. The relation between arc length and voltage was found to be non-linear and dependent on the slag composition. The voltage gradients of the arcs were evaluated as a function of arc length and sum of anode and cathode voltage drops resulting in a reciprocal relation. Furthermore, the electrical conductivity of the arc plasma with respect to arc length was estimated.