Optimizing flow patterns and residence time in a two-strand steelmaking tundish via PIV and tracer-based flow detection

The tundish plays a crucial role in the production of high-quality steel by removing impurities and preventing defects caused by inclusions during the continuous-casting process. Thus, one approach to enhancing the product quality is to increase the residence time of molten steel inside the tundish. In this study, a 1:6 scale water model was used to analyze the fluid flow and residence time in a tundish. KMnO4 was employed as an indicator to detect flow patterns and measure the influence of 23 cases comprising different dam and weir positions. Then, particle image velocimetry (PIV) was used to analyze the flow patterns and velocity fields of selected cases in detail. The effects of different configurations on the patterns, uniform velocity, and dead zones of the flow were assessed in an effort to improve the impurity removal performance. The results revealed that the diffuser arrangement of the weir and dam with a 15-degree angle at an optimal distance of 10 cm from the entrance exhibited the highest increase in residence time, achieving a 120% improvement compared to the case without the weir and dam. Furthermore, the PIV analysis demonstrated that placing the weir at an angle effectively distributed velocity momentum uniformly throughout the flow, which eliminated dead zones, and prolonged the residence time.