Criteria for early detection of slag in steel casting

The paper addresses the issue of early detection of steel ladle slag in the continuous casting of steel. In this study, the vibration method of slag detection was evaluated due to the high informative value of the vibration signal. The analysis is based on the variation in the character of the vibration acceleration signal of the protective tube manipulator of the continuous casting machine when slag enters the intermediate ladle. The envelope method of the vibration power spectrum was used to derive five empirical criteria for slag cut-off. In addition, these criteria included data on the molten mass in order to reduce the occurrence of false alarms. A generalized measure was developed to determine the performance quality of the criteria which was estimated to be 91.79%. This result validates the efficiency of these criteria and their suitability for testing in real production conditions.