DISTRIBUTED FIBER-OPTIC TEMPERATURE SENSORS FOR APPLICATIONS IN THE STEEL INDUSTRY

Steelmaking facilities require continuous temperature measurements throughout the manufacturing process to ensure consistent product quality and high productivity. Motivated by the limitations of conventional temperature sensors, distributed fiber-optic sensors (DFOS) were developed and deployed for various applications in the steel industry. Fiber-optic sensors offer various advantages over conventional sensors, such as the miniaturized size of the optical fiber, immunity to electromagnetic interferences, capability for multiplexing and distributed sensing, and the ability to withstand harsh environments. Firstly, high-resolution Rayleigh backscattering based DFOS were demonstrated as potential solutions for temperature measurements in steelmaking processes by performing experimental simulations. Additionally, aluminum casting experiments were conducted to demonstrate the measurement capability of DFOS in solidifying metal alloys. Temperatures exceeding 700 ℃ were measured at sub-millimeter spatial resolution (~ 0.65 mm) and at milliseconds sampling speeds. Moreover, a novel dip testing paddle was developed employing a copper mold instrumented with optical fiber. The instrumented mold was used to perform steel dip tests in a 200 lb induction furnace in a foundry laboratory. The results obtained from temperature measurements provided strong evidence that the dip testing paddle can be a useful apparatus for the investigation of the fundamental reactions occurring in a continuous casting mold. The present study demonstrated that DFOS can be transformative to the steel industry by enabling efficient process control, reducing energy and maintenance costs, improving the safety of equipment and workers, and enhancing the quality and yield of metal products --Abstract, p. i