Real-time Optical Sensing and Analysis for Understanding Extreme Metal Production Processes

This paper presents a concept for a novel sensing system based on digital laser technology for reliable imaging and robust analysis in extreme environments of the metallurgical industry. Metal production processes present harsh operating conditions for conventional sensors, having extreme temperature, high dust loading, dense vapours and smoke, and thus challenging the continuous automated process control. In this paper, we present a sensor system based on precise time-of-flight laser range measurements for enabling continuous monitoring of molten metal in extreme process conditions. By allowing a high number of measurements per second (100 Hz) and digitizing the echo signal at a specific near-infrared wavelength, the sensor system allows the application of digital signal processing algorithms for high-penetration ranging even under bad visibility conditions. The first test in a laboratory induction furnace shows the capabilities of the system concept in imaging the surface through heavy smoke and dust at high-temperature operating conditions of more than 1600 °C.