(1. Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Wuhan University
of Science and Technology, Wuhan 430081, Hubei, China;2. Hubei Provincial Key Laboratory for New Processes
of Ironmaking and Steelmaking, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China;
3. Yinshan Section Steel Co., Ltd., Laiwu Steel Group, Laiwu 271104, Shandong, China)
Abstract:The annular argon blowing at the upper nozzle of tundish can form an annular gas curtain around the stopper rod to clean the molten steel. At the same time, part of argon bubbles enter the upper nozzle with the molten steel, which can reduce the adhesion of nonmetallic inclusions on the inner wall of the nozzle and prevent the clogging of the nozzle. However, the unreasonable argon flow rate could cause the upper slag layer to be impacted by the excessive gasliquid bubble plumes to form a slag eye, which makes the molten steel exposed and reoxidized, reducing the slab quality. In the present work, the standard kε turbulence model is used to solve the fluid flow in the tundish. The DPM model and the VOF model coupling method are used to study the formation and evolution of the slag eye with the annular argon blowing at the upper nozzle of tundish. The results show that a strong upwelling flow is formed around the stopper rod, and there are multiple vortex flows in the vicinity of the upper part of the stopper rod. Under the influence of the vortex flow, the lower layer of liquid slag move away from the stopper rod and the upper layer flows from the periphery to the stopper rod. With increased argon flow rate, the average turbulent kinetic energy and velocity of molten steel around stopper rod increases gradually, and the molten steel velocity at the interface of steelslag increases first and then decreases. The molten steel velocity at the edge of slag eye increases initially, followed by a decrease, but then again increases, accompanied by the decrease of velocity angle with the vertical direction. With the further increase of the argon flow rate, a donutshaped slag eye centered on stopper rod is formed on the tundish liquid level, and the area of slag eye gradually increase. The critical argon flow rate of slageyefree is 4.2 L/min in this study, at which the liquid steel velocity of steelslag interface reaches 0.247 m/s, and the dip angle with vertical direction is 70°.
秦绪锋,程常桂,李阳,张春明,金焱,武光君. 上水口环形吹氩对中间包内渣眼形成的影响[J]. 钢铁, 2019, 54(8): 107-115.
QIN Xufeng,CHENG Changgui,LI Yang,ZHANG Chunming,. Effect of annular argon blowing at upper nozzle on #br# formation of slag eye in tundish. Iron and Steel, 2019, 54(8): 107-115.