Application of Tanks-in-Series Model to Characterize Non-Ideal Flow Regimes in Continuous Casting Tundish

• Published in: Metals (Basel ) 2021, Vol.11 (2), p.208
• Main Authors: Sheng, Dong-Yuan, Zou, Zongshu
• Format: Article
• Language: English
• Subjects: Beads; clean steel; Computational fluid dynamics; computational fluid dynamics (CFD); Continuous casting; Evaluation; Experiments; Flotation; Fluid flow; inclusion removal; Kinetic energy; Nonmetallic inclusions; Physical simulation; Plug flow; residence-time distribution (RTD); tanks-in-series; Tundishes; water model; Water tanks
• ISSN: 2075-4701; 2075-4701
• DOI: 10.3390/met11020208

This study describes a new tanks-in-series model for analyzing non-ideal flow regimes in a single-strand tundish. The tundish was divided into two interconnected tanks, namely an inlet tank and an outlet tank. A water model experiment was carried out to separately measure the residence-time distribution (RTD) of the two tanks. Drift beads were adopted in the water model experiment to simulate the non-metallic inclusions in molten steel. Dead volume fraction was evaluated by analyzing measured RTD curves. The ratio between mixed flow volume and plug flow volume was proposed as a new criterion to evaluate the inclusion removal. In the inlet tank, a higher mixed flow fraction was preferred to effectively release turbulent kinetic energy and enhance inclusion collision growth. In the outlet tank, a higher plug flow fraction was preferred to facilitate inclusion removal by flotation. The optimal positions of the weir were recommended based on the RTD analysis and the inclusion removal from the results of water model experiments. A theoretical equation was derived based on the tanks-in-series model, providing a good fitting function to analyze the experimental data. The confirmation test was performed by applying computational fluid dynamics simulations of liquid steel flow in the real tundish.