Skin and Proximity Effects in Electrodes and Furnace Shells

A review of two-dimensional (2D) analytical models of skin and proximity effects in large industrial furnaces with three electrodes arranged in an equilateral triangle is given. The models cover three different cases: one electrode only, three electrodes where two are approximated by line currents, and induced shell currents where all electrodes are approximated by line currents. The first two models show how the skin and proximity effects depend on electrode material properties and size, and the distance between the electrodes. The third model shows how the strength of the induced shell currents will depend on electrode position and furnace size. These models are compared to numerical studies including distributed electrodes and shell currents. The analytical models are accurate when induced shell currents can be disregarded. However, strong shell currents may have a significant impact on the current distribution within the electrodes. This electrode-shell proximity effect competes with the electrode-electrode proximity effect. Finally, the 2D models have been compared with three-dimensional (3D) case studies of large industrial furnaces. In 3D, the shell currents are significantly smaller than what are predicted by the 2D models, but they are sufficiently strong to cause a significant correction of the electrode current density.Skin and Proximity Effects in Electrodes and Furnace ShellspublishedVersio

Metamodeling of the Electrical Conditions in Submerged Arc Furnaces

Physics-based Finite Element Methods models can be used to investigate the electrical conditions in submerged arc furnaces (SAFs). However, their explicit solution may be very demanding in terms of time and computational resources. This makes these models difficult to employ during control operations and in fast prototyping. To obviate these inconveniences, we developed metamodels that are grounded on the physics-based model. In this context, a metamodel is a surrogate of an original model obtained using statistical analysis tools to determine approximate input–output relationships in a database of simulations from the original model. The metamodels for the SAF electrical conditions are shown to retain the same generalization capabilities as the original model while being computationally lightweight