Four-flow Tundish Curtains Device Optimization And Surface Slag Entrapment Research

Tundish is an important reactor in continuous casting process. Tundish’s functions are depositing molten steel,distributing molten steel and purifying molten steel. The reasonable flow control devices can adjust the condition of thefluid flow, average the temperature of the steel and promote the inclusions to float. The paper makes research on afour-strand tundish of a domestic steel plant, the mathematical simulation and physical simulation method were used tosimulate the flow field and temperature field in different flow control device plans. Then to choose the best flowcontrol devices by using physical simulation to verify. Next, the critical height of the free surface slag entrapment onthe end of pouring is simulated. It studied the slag entrapment height of different casting and the vortex formationprocess.Mathematical simulation shows that the local flow control device is unreasonable. The flow control ability to thedistal outlet is weak, so the range of temperature in the tundish and different outlet is high, the result is10.4℃and8.9℃.The optimized scheme can effectively improve the molten steel flow condition in the tundish.Based on similarity principle, simulating the flow field in local tundish and studying the effects of arc openingguide wall and arc groove guide wall on the behavior of liquid flow in tundish. The results of water modeling show thatthe original tundish’s valume of the inner cavity is relatively small, so the minimum residence time and peak time ofeach strand are both short, and the tundish has higher dead volume fractions, which affecting the production runsmoothly of steelmaking. With the optimized tundish flow control device of arc opening guide wall and turbulencecontroller, the volume of impacting zone is bigger than before, and the flow control function is strengthen than before.The flow characteristics of molten steel are greatly improved. After optimization, the dead volume fractions of the firststrand and the second strand was reduced12.3%and12.1%, meaning that detention time has increased39s and52srespectively.The mathematical simulation on the pouring stage surface slag entrapment critical height shows that vortexoriginates from the outlet and develops upward with its scope enlarging. Casting speed on the effects of the criticalheight is larger. The greater of the casting speed, the higher of the critical height. When the free surface is higher, thesurface of molten steel flow direction is horizontal or nearly horizontal direction, the influence of liquid steel flow ismainly controlled by the liquid level fluctuation. When the free surface decreases, the direction of flow above the exitis radial flow. The vortex has relatively great influence on free surface at the exit. The vortex is constantly development,deterioration until coalescence.