Vacuum tank degassing

The objective of the vacuum tank degassing treament is to remove tramp elements, such as oxygen, hydrogen, nitrogen or sulphur, from the steel. These aims are achieved by gas-stirring under vacuum atmosphere. However, clogging of the bottom nozzles constitutes a major problem. In order to counter this problem, vibration-based method was used to identify the effectivity of gas stirring and identify malfunctions.

Highlights

• A test installation of a vibration-based monitoring system was conducted. On the basis of the results obtained, two indices were proposed for control purposes. 

Selected publications

• M. Pylvänäinen, V.-V. Visuri, J. Nissilä, J. Laurila, K. Karioja, S. Ollila, T. Fabritius, and T. Liedes, “Vibration-Based Monitoring of Gas-Stirring Intensity in Vacuum Tank Degassing,” Steel Research International, vol. 91, no. 6, 1900587, 2020.
• M. Pylvänäinen, V.-V. Visuri, T. Liedes, J. Laurila, K. Karioja, S. Pikkupeura, S. Ollila, and T. Fabritius, ”Vibration-based Assessment of Gas Stirring Intensity in Ladle Treatments”, Proceedings of the 5th International Conference on Process Development in Iron and Steelmaking, Swerea MEFOS, Luleå, Sweden, no. 14, 2016.