レードルからの溶鋼注入における光学方式スラグ流出検知装置の開発

抄録

In a continuous casting process, it has been desired to detect slag entrained to a teeming stream from a ladle to a tundish under sealed condition in order to protect molten steel from reoxidization. "Detection system for slag entrained to teeming stream" which enables to detect slag in the teeming stream effectively by an optical method is developed.
The principle of the slag detection is based on the difference in emissivity and a stream diameter between slag and steel. Both the emissivity and the stream diameter of slag are larger than those of steel.
This system was tested in continuous casting processes. The mean value of the optical power from slag is about 1.54 times of that from molten steel only. Its mean value from molten steel mixed with slag is about 1.2 times of that from molten steel only. The timing of alarm outputs from the system were compared with the timing of visual detection for 35 times. 97% of alarm output timing appeared in 5 secs before visual detection. And successful results were also obtained from all of the sealing pour tests without visual detection.
Developed detection system for slag entrained to teeming stream by the optical method which has the features of simple probe structure, easy operation and high accurate slag detection, is expected to contribute to stable operation and casting of good quality products in continuous casting machines.