Effect of an Optimised Impact Pad on Molten Steel Quality in a 4 Strand Delta-shaped Tundish

The tundish plays an important role to produce refined steel as well as acting in its traditional role as a steel distribution vessel. Presently, a tundish fitted with different flow control devices, such as an impact pad, dams, weirs, baffles, etc. is used to provide the maximum opportunity for carrying out various metallurgical operations such as inclusion separation, superheat control, reduced slag entrapment and to provide thermal and particulate homogenization. Modelling has shown that a correctly designed impact pad in a continuous casting tundish can significantly reduce the amounts of slag entrained into individual moulds during ladle change operations. It can also minimize non-metallic inclusions reporting to the final product by improving inclusion flotation efficiency. Water can be used for the physical simulation, because the kinematic viscosities of liquid steel (at 1600°C) and water (at 20°C) are equivalent. In this one third scale water modeling work, the effects of an optimized impact pad on molten steel quality was evaluated in terms of "slag" entrainment during a ladle change, together with tracer dispersion studies and residence time distribution (RTD) analyses for isothermal and non-isothermal cases (temperature differences in between incoming fluid and existing fluid within the tundish) so as to visualize flow patterns developing within the tundish. Furthermore, the effect of increasing the molten steel capacity within the tundish by raising the liquid level, on the degree of slag entrainment during ladle changing operations, was also demonstrated.%%%%Le Tundish joue un role important dans la production de l'acier raffine ainsi que d'agir dans son role traditionnel d'un recipient de la distribution d'acier. Actuellement, un Tundish equipe de divers dispositifs de commande d'ecoulement tels comme amortisseur d'impact, barrage, deversoirs, baffles, etc. est utilise pour fournir le maximum de chances pour la realisation de diverses operations metallurgiques tels que la separation d'inclusions, alliage rognage, reglage de la surchauffe, reduit piegeage de scories et pour fournir une homogeneisation thermique et de particules. La modelisation a montre que la conception d'un approprie amortisseur d'impact dans un Tundish de coulee continue permet de reduire de facon significativement les quantites de scories piegeage dans des moules individuels pendant les operations de changement de louche. Cela reduit egalement les inclusions non metalliques et ameliore le produit final en raison d'une plus grande efficacite de la flottation.L'eau peut etre utilisee pour la simulation physique, parce que la viscosite cinematique de l'acier liquide (1600°C) et de l'eau (20°C) sont equivalentes. A une echelle 1/3 du travail de modelisation, l'effet d'un optimale amortisseur d'impact sur la qualite d'acier fondu a ete evaluee en termes de piegeage de scorie pendant le changement de "ladle", cette avec l'etude de la dispersion de traceurs et les analyses de la distribution des temps de sejour (RTD) pour les cas…

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