Abstract: At the end of ladle teeming, the molten steel will produce confluence vortex under the action of the Coriolis force and its own initial state, which becomes a bottleneck for controlling ladle slagging and enhancing molten steel yield. Taking a 150 t single-nozzle ladle in a steel plant as a prototype, a physical model of the ladle with a similarity ratio of 1∶3.5 was established based on the principle of similarity, and the influence degree and mechanism of the nozzle eccentricity on the confluence vortex at the end of teeming were first explored, then the effects of the ladle standing time, the anti-vortex device and the bottom stirring process, and other flow-control measures on the confluence vortex in the ladle with an eccentricity of 0.83 were investigated. The results show that the formation of asymmetric flow field in the ladle can inhibit the development of vortex. When the standing time of the ladle is less than 45 min, the change of the formation height and penetration height of vortexis are not obvious with the extended standing time, but when the standing time is more than 45 min, the formation height of vortex increases significantly and the penetration height decreases obviously. In addition, at an eccentricity of 0.83, neither the installation of anti-vortex device nor the addition of bottom blowing stirring operation can suppress the vortex, but closing the nozzle briefly during vortex initiation can delay the subsequent development of the vortex.

Key words: ladle, confluence vortex, eccentricity, bottom stirring, nozzle closure