Design of a Submerged Entry Nozzle for T

This study presents the development of a submerged entry nozzle (SEN) designed for thin slab casters operating at high casting speeds of up to 7.5 m/min, rooted in boundary-layer theory and water modeling experiments. The research employed various experimental techniques, including tracer injection to visualize fluid flow patterns, high-speed video and image analysis to monitor changes in meniscus levels, and particle image velocimetry to assess water speeds within the mold. The new SEN design was compared with two existing nozzle designs currently in commercial use at thin slab casters. Results from direct comparisons of mathematical simulations and experimental outcomes demonstrated that the new SEN provides very stable flows independent of casting speed and nozzle immersion depth, characterized by a double roll flow pattern without the formation of surface vortices. In contrast, the other SEN designs exhibited unstable discharging jets due to excessive shearing effects, leading to significant kinetic energy dissipation and substantial meniscus oscillations. Notably, the proposed design has shown promising industrial performance and extended operational life owing to reduced wear on the slag protection belt, attributed to lower bath velocities in contact with the SEN wall.