Electromagnetic modelling of three-phase AC furnaces. Applications in metallurgical processes

Abstract

Submerged Arc Furnaces (SAFs) are large electric arc furnaces used primarily in the production of ferromanganese (FeMn) and other ferroalloys. Smelting processes run at high temperatures and power is normally supplied by intensive three-phase alternating current (AC). Measurements of internal conditions are difficult or impossible to obtain and several process variations are not properly understood. The project “Electrical Conditions and their Process Interactions in High Temperature Metallurgical Reactors (ElMet)” has applied mathematical modelling to increase this knowledge. The project has involved close collaboration between NORCE Norwegian Research Centre, the companies Elkem and Eramet Norway, the Norwegian University of Science and Technology and the Universities of Oxford and Santiago de Compostela, the latter through the Technological Institute for Industrial Mathematics (now integrated in CITMAga). This thesis has been developed in the framework of ElMet. It has focused on studying reduced dimensional models using both analytical and numerical methods. More real furnace simulations have been carried out in 2D and 3D. New fundamental knowledge on AC inductive effects has been acquired by analysing comparatively simple 1D and 2D models. The models have been applied to different regions of smelting furnaces. Among others, good insights have been obtained on induced currents in the furnace steel shell and carbon lining.