Optimization of post combustion in an electric arc furnace for advanced steelmaking

Abstract

In the state-of-the-art electric arc furnace (EAF) flat-rolled steelmaking plant, about 1.5 kmol of CO is generated per ton of steel, which if combusted to CO2, represents 425 MJ of energy recovery. Efficient transfer of the heat energy from the post combustion (PC) to the molten steel bath can reduce production costs and improve productivity. A comprehensive CFD model was developed to simulate the process. It was applied to the PC process in an industrial scale EAF furnace. Different PC oxygen injection system designs and operational strategies were evaluated e. g energy transfer efficiency, emission reduction ratio, oxygen usage efficiency. It was observed that only a simple modification of the PC system can improve greatly the system performance and hence reduce the steelmaking cost due to reduced energy consumption and decreased melting time in the EAF furnace. The numerical results obtained here also improve our current understanding of the PC process. This CFD model can be used as a tool to optimize existing industrial EAF furnaces.