Effects of Steel Scrap Oxidation on Scrap Preheating Process in an Electric Arc Furnace

The electric arc furnace (EAF) is used to produce steel, primarily from steel scraps, using electricity and chemical energy. Oxy-fuel burners firing natural gas (NG) are widely used in EAF operation during both the scrap preheating and melting stages. Excess oxygen is normally used to improve heating efficiency. Steel scrap oxidation increases the scrap temperature and reduces the scrap melting point. In this paper, a numerical study is conducted to simulate the steel scrap preheating process using oxy-fuel combustion. A three-dimensional computational fluid dynamics (CFD) model was developed with detailed consideration of gas flow, oxy-fuel combustion, scrap oxidation and multi-mode heat transfer between gas and solid scrap. The effects of scrap oxidation on the scrap preheating were also investigated. Model validation was conducted using experimental data obtained from a small-scale scrap preheating furnace. The model can be applied to industrial EAFs to investigate the effects of operating parameters on the scrap preheating process.