Measurement and analysis of the impedance of electrodes in arc furnaces for silicon production

This paper presents an automated system for the remote measurement and analysis of the impedance of the electrodes in submerged arc furnaces used in silicon production facilities worldwide. The system plays a key role in the efficient on-line monitoring of the furnace that, as demonstrated in previous works, is useful not only to check the operation, but also to determine the values of some important parameters of the furnace. The system also allows an off-line analysis of the measurements to be carried out, which can be useful to identify ways to refine the monitoring process. The paper describes the structure and operation of the system, and its integration with both the furnace and the control network of the plant. Experimental results collected at the silicon production facility of the company Ferroatlantica, in Spain are presented and discussed.