Effect of carbide configuration on the current distribution in submerged arc furnaces for silicon production—A modelling approach

Abstract

Current distribution is critical for good operation of Submerged Arc Furnaces for silicon production. Control systems do not offer this information as it is not directly measureable, but metallurgists operate furnaces based on experienced interpretation of available data. A number of recent dig-outs of industrial furnaces has expanded available information on location dependent charge properties, thus enabling numerical models with reasonably realistic domain configurations. This has the potential to enhance understanding of critical process parameters allowing more accurate furnace control. This work presents computations of electric current distributions inside an industrial submerged arc furnace for silicon production. A 3D model has been developed in ANSYS Fluent using electric potential solver. Electrode, arc, crater, crater wall, and side arc that connects electrode and crater wall are considered for each phase. In this paper the current distributions in electrode, arc and crater wall for different configurations and thickness of the crater walls are presented. The side-arcs are modelled as either a single concentrated arc, or a smeared out arc, in order to capture extreme cases. The main result is that side arc configuration is more important for the fraction of the current passing through the crater wall than the carbide thickness. The current fraction bypassing the main arc through the charge is highly influenced by the ease of contact between electrode and conducting charge material. Qualitatively, the results are in a good agreement with previously published results from literature.