Multiphase Flow Behavior in a Single-Strand Continuous Casting Tundish during Ladle Change

• Published in: ISIJ International Vol. 60; no. 3; pp. 499 - 508
• Main Authors: Ling, Haitao, Xu, Rui, Wang, Haijun, Chang, Lizhong, Qiu, Shengtao
• Format: Journal Article
• Language: English
• Published: The Iron and Steel Institute of Japan 15.03.2020
• Subjects: ladle change; numerical simulation; physical modeling; slag entrainment; slag exposure; tundish
• ISSN: 0915-1559; 1347-5460
• DOI: 10.2355/isijinternational.ISIJINT-2019-506

The three-phase flow behavior in a single-strand continuous casting tundish during ladle change was investigated using physical modeling. These phenomena observed from physical modeling were explained by employing the multiphase model volume of fluid, which can track the interface behavior between the liquid steel, slag, and air during this operation. The effects of the refilling time and lowest operating level on the slag entrainment and the steel exposure during ladle change were analyzed and discussed, respectively. Increasing the refilling time significantly decreased the amount of entrained oil and the exposed area in the impact zone during ladle change. However, the increase in the lowest level had little influence on reducing the slag entrainment. To reduce the slag entrainment and the steel exposure during ladle change, the refilling time in the prototype should be larger than 3 minutes. Furthermore, the use of the turbulence inhibitor has also been evaluated. By diminishing the turbulence intensity in the impact zone and the velocity magnitude at the steel-slag interface, the turbulence inhibitor reduced considerably the amount of entrained slag and the steel reoxidation. The results indicated that the emulsification phenomenon during ladle change could be eliminated using TI-2, and the maximum exposed area fractions in the impact zone for different refilling times and lowest levels were less than 13% and 23%, respectively. Therefore, the TI-2 was recommended to improve the steel cleanliness during ladle change.