Effect of Process Parameters on Thermal Response of an Oxy-Fuel Burner/Injector Panel in an Electric Arc Furnace via Fiber Optic Sensors

Abstract Modern oxy-fuel burner/injectors in electric arc furnaces (EAFs) play a critical role in scrap melting, liquid steel refining, and slag foaming. However, varying operational modes, combined with dynamic process conditions, such as arcing and slag behavior, can expose the injector panel surface to intense thermal conditions that can compromise efficiency and safety. Conventional monitoring techniques, including cooling water temperature measurements and thermocouples, fail to capture localized thermal anomalies due to their limited spatial resolution and susceptibility to electromagnetic interference. In this study, four high-resolution Rayleigh backscattering-based fiber optic sensors, interrogated via optical frequency domain reflectometry, were embedded in top and bottom slot of the oxy-fuel burner/injector panel of a DC EAF with an average heat size of 77 metric tons. The sensors were placed at 28.7 mm away from the hot face of the panel and continuously monitored the temperature during two production days of EAF steelmaking. The sensors successfully identified localized hot spots, provided spatially resolved temperature distributions, and correlated thermal behavior with key process parameters such as furnace power, oxygen flow, and carbon injection. Elevated temperatures approaching or exceeding 100 °C were observed in the top region of the panel after the second scrap charge in six of the 47 heat cycles. The temperature distributions from the two different sensors from the top slot aligned with each other. The results revealed that inconsistent slag coverage on the injector panel’s hot face during specific periods of operation was a primary factor in localized overheating. These findings demonstrate the potential of using distributed fiber optic sensing to enhance thermal management of oxy-fuel systems, optimize energy usage, and improve operational safety in modern EAF steelmaking.