High-Temperature Distributed Sapphire Optical Fiber Sensors for Monitoring Temperatures at Various Depths in a Continuous Caster Tundish
Abstract
A 1-meter-long sapphire optical fiber, featuring cascaded sapphire Fiber Bragg Gratings (sFBGs) inscribed using femtosecond laser (FS-laser) technology in a distributed configuration, has been demonstrated in a continuous tundish temperature probe application in a production environment. The probe is capable of withstanding temperatures greater than 1600°C, and its long-term stability has been demonstrated both in a lab environment over a 72-hour period and in a production environment at SSAB Montpelier, Iowa, where it successfully captured a long sequence of heats. The sapphire fiber-optic tundish probe consisted of a 1-meter sapphire fiber sheathed in a sapphire tube that was placed within a commercial refractory temperature probe housing supplied by Vesuvius. The distributed sFBG sensors on the sapphire fiber enable real-time, continuous monitoring of the tundish temperature at various depths in the tundish, including within the metal and slag layers. This distributed mapping provides significant advantages over traditional immersion probes, as it enables temperature monitoring at various depths, allowing the tundish level to be tracked during ladle exchanges and tundish drains and offering the potential for observing temperature stratification in the tundish. The sapphire fiber sensor system offers new insights into the tundish's thermal behavior on a continuous basis throughout the entire cast sequence and demonstrates the ability of sapphire optical fibers to provide robust, real-time sensing under the extreme conditions of steel production, improving process monitoring and potentially leading to better control over the steelmaking process.
Recommended Citation
H. Tekle and F. Mumtaz and T. Sander and B. Zhang and J. Insana and M. Leite and D. Brown and Y. Wang and D. Palmer and S. Abraham and J. D. Smith and R. J. O'Malley and J. Huang, "High-Temperature Distributed Sapphire Optical Fiber Sensors for Monitoring Temperatures at Various Depths in a Continuous Caster Tundish," Aistech Iron and Steel Technology Conference Proceedings, pp. 1180 - 1190, Association for Iron and Steel Technology, Jan 2025.
The definitive version is available at https://doi.org/10.33313/389/127
Department(s)
Materials Science and Engineering
Second Department
Electrical and Computer Engineering
Keywords and Phrases
Cascaded Fiber Bragg Gratings (FBGs); High-Temperature Sensing; Sapphire Optical Fiber; Steelmaking Process; Tundish Monitoring
International Standard Book Number (ISBN)
978-093076737-2
International Standard Serial Number (ISSN)
1551-6997
Document Type
Article - Conference proceedings
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2025 Association for Iron and Steel Technology, All rights reserved.
Publication Date
01 Jan 2025
Comments
U.S. Department of Energy, Grant DE-EE0009392