Influence of immersion depth of ladle shroud in liquid steel on range of transition zone for one-strand tundish during continuous casting of steel Wpływ głębokości zanurzenia wylewu osłonowego w ciekłej stali na zakres strefy przejściowej dla jednowylewowej kadzi pośredniej podczas ciągłego odlewania stali AbstractThis article presents the results of a computer simulation of the flow of liquid steel through a onestrand tundish. In this paper, we examine four immersion depths of a ladle shroud in liquid steel. The simulation was performed for a sequence of slab castings. The effect of the calculations were residence time distribution curves (RTD), type (F). Based on the distribution curves, the range of the transition zone for the different variants of the immersion depth of a ladle shroud were estimated. Based on the results of numerical calculations, it was found that increasing the immersion depth of the ladle shroud in liquid steel influences the range of the transition zone. For numerical simulations of the flow of liquid steel, the Ansys-Fluent program was used. Keywords: sequence casting, tundish, ladle shroud, numerical modeling, transition zone Streszczenie W artykule przedstawiono wyniki symulacji komputerowej przepływu ciekłej stali przez jednowylewową kadź pośrednią. W pracy rozpatrzono cztery głębokości zanurzenia wylewu osło-nowego w ciekłej stali. Symulację wykonano dla sekwencji odlewania wlewków płaskich. Efektem obliczeń było uzyskanie krzywych czasu przebywania RTD (Residence Time Distributions) typu (F). Na podstawie rozkładu krzywych oszacowano zakres strefy przejściowej dla poszczególnych wariantów głębokości zanurzenia wylewu osłonowego. Na podstawie wyników

This work presents the numerical and physical simulation results of the liquid steel flow in the one-strand tundish. The results obtained during the numerical simulations and the water modeling results were compared to each other. Six types of turbulence models were tested. Among tested turbulence models the BSL k-ω was turned out the best correlating with the results from the laboratory experiments. Besides, the ladle shroud modification was proposed by the authors and the influence of the modified ladle shroud immersion depth in the liquid steel on the hydrodynamic structure in the tundish was checked. The ladle shroud modification depended on the expansion, narrowing, and re-expansion of the liquid steel feed stream. The four tundish variants with the four different ladle shroud immersion depths (at 0.1, 0.2, 0.3 and 0.4 m) in the liquid steel were tested. The liquid steel flow volumes were calculated and according to the generated active flow volume, the most beneficial research case was indicated. The tundish variant with the ladle shroud immersion depth of 0.3 m in the liquid steel was characterized by the lowest stagnant flow volume. The numerical simulations were performed by using the Ansys-Fluent computer program.

In this work, the authors proposed a modification of the working space one-strand tundish adapted for slab casting process. Numerical simulations of liquid steel flow in the considered flow reactor were performed. The tundish is equipped with a dam with a multi-hole filter. Two variants of the filter hole arrangement were tested and their effect on the liquid steel flow hydrodynamic structure in the tundish was examined. The computer calculations results were verified by performing experiments on the water model. The result of numerical and physical simulations an RTD (Residence Time Distribution) type F curve was generated, which define the transition zone between the cast steel grades during the sequential casting process. The results of the researches showed that the modification of a dam with a multi-hole filter affects on the formation of the liquid steel flow hydrodynamic structure and the transition zone. Furthermore, examinations of the liquid steel refining ability in the considered tundish were carried out. The influence of the filter holes arrangement on the non-metallic inclusions flotation process to the slag phase and liquid steel filtration processes was checked. Numerical simulations were performed in the Ansys-Fluent computer program.

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Influence of ladle shroud and change in its position on liquid steel flow hydrodynamic structure in six-strand tundish Wpływ wylewu osłonowego kadzi stalowniczej i zmiany jego położenia na strukturę hydrodynamiczną przepływu ciekłej stali w sześciowylewowej kadzi pośredniej Abstract This paper presents the numerical simulation results of the liquid steel flow in a six-strand tundish used for casting billets. The influence of using a ladle shroud, changing its immersion depth in liquid steel on the transition zone, and shaping the liquid steel volume flow were tested. Three positions of the ladle shroud immersion depth in liquid steel were checked. The computer calculation results have shown that the use and position change of the ladle shroud locally influences the shape of the liquid steel hydrodynamic structure in the tundish. The numerical simulations were carried out using the Ansys-Fluent computer program. StreszczenieW niniejszej pracy przedstawiono wyniki symulacji numerycznych przepływu ciekłej stali w sześciowylewowej kadzi pośredniej przeznaczonej do odlewania wlewków kwadratowych. Testowano wpływ zastosowania wylewu osłonowego i zmiany jego głębokości zanurzenia w ciekłej stali na zakres strefy przejściowej i kształtowanie udziałów przepływu ciekłej stali. Sprawdzono trzy głębokości zanurzenia wylewu osłonowego w ciekłej stali. Rezultaty obliczeń komputerowych wykazały, iż zastosowanie i zmiana położenia wylewu osłonowego wpływa lokalnie na kształt struktury hydrodynamicznej przepływu ciekłej stali w kadzi pośredniej. Symulacje numeryczne zrealizowano z wykorzystaniem programu komputerowego Ansys-Fluent. Słowa kluczowe: kadź pośrednia, ciągłe odlewanie stali, symulacja numeryczna, wylew osłonowy kadzi stalowniczej