FEM computation of the forces on the arc of a DC-furnace

A finite element model of a DC arc furnace is investigated in order to predict the forces acting on the arc due to the magnetic field. The currents have an a priori unknown distribution in the steel tank wall, in the anode, in the melt and in the cathode, so a current flow problem is analysed in the first step. The current density is solved for in terms of a current vector potential whose edge element representation is used in the subsequent nonlinear magnetic field calculation to act as impressed magnetic field. The current dependence of the shielding provided by the steel tank is investigated. It is shown that by providing an asymmetrical feed of the current, the force on the arc can be reduced substantially