Numerical Prediction of Hydrodynamic Conditions in one Strand Tundish. Influence of Thermal Conditions and Casting Speed/ Numeryczna Prognoza Warunków Hydrodynamicznych W Jednozyłowej Kadzi Posredniej. Wpływ Warunków Cieplnych I Predkosci Odlewania

Abstract

This paper reports the results of computer simulations of the flow of liquid steel in a single-nozzle tundish, which describe the flow hydrodynamics, depending on the thermal conditions and casting speed. In this paper, five casting speeds, namely 0.3, 0.6, 0.9, 1.2 and 1.5 m/min., have been examined. In view of the fact that tundishes are being equipped with various flow control devices and the process of creating specific hydrodynamic conditions is influenced also by the temperature gradient, computer simulations of liquid steel flow under isothermal and non-isothermal conditions were performed. Computer simulations of liquid steel flow were performed using the commercial program Ansys-Fluent R . In order to explain the phenomena occurring in the tundish working space, the buoyancy number (Bu) has been calculated. The next research step in the analysis of the flow pattern forming in different casting conditions was to record the E and F-type RTD characteristics and to describe the pattern of flow.Keywords: tundish, steel flow, numerical modeling, thermal conditions, casting speed Praca przedstawia wyniki symulacji komputerowej opisującej wpływ warunków cieplnych i prędkości odlewania na przepływ ciekłej stali w jedno-wylewowej kadzi pośredniej. W pracy testowano pięć prędkości odlewania: 0,3; 0,6; 0,9; 1,2 i 1,5 m/min. Ze względu na gradient temperatury powstający w objętości ciekłej stali i stosowanie w kadziach pośrednich urządzeń sterujących przepływem, symulacje komputerową przepływu ciekłej stali wykonano dla warunków izotermicznych i nieizotermicznych. Symulacje komputerową przepływu ciekłej stali wykonano za pomocą programu Ansys-Fluent R . Dla wyjaśnienia zjawisk występujących w przestrzeni roboczej kadzi pośredniej obliczono liczbę wyporu (Bu). Do analizy struktury hydrodynamicznej przepływu ciekłej stali w różnych warunkach odlewania zarejestrowano krzywe czasu przebywania typu E i F.

Effect of Uniform and Non-Uniform Increasing Casting Flow Rate on Dispersion and Outflow Percentage of Tracers in Four Strand Tundishes under Strand Blockage Conditions

“…Year Tundish Type Research Focus T. Merder [19] 2013 two-strand dead volume and well mixed volume K. Raghavendra. et al [23] 2013 four-strand inclusion separation efficiency A. Cwudzinski [25] 2014 single-strand temperatures difference B. Bul'ko. et al [20] 2018 two-strand residence time F. He.…”

“…In another study [24], it was found that the molten steel free surface would trap more inclusions when the casting speed was increased from 1.0 to 1.2 m/min. For the temperature field, it was found that the lower the casting speeds, the larger the difference between the temperatures of the steel flowing to the tundish and the steel flowing to the mold [25]. Meanwhile, F. He et al [26] indicated that flow characteristics in the tundish that only increase the far-strand's casting speed are better than those for increasing the casting speed of each strand simultaneously.…”

“…25 shows the isosurfaces (values of 10 −5 ) of non-uniform increasing of casting flow rate cases of the u-shaped weir tundish under strand 1 blockage conditions. The flow field and tracer dispersion are basically the same for the three cases.…”

Effects of Salt Tracer Volume and Concentration on Residence Time Distribution Curves for Characterization of Liquid Steel Behavior in Metallurgical Tundish

“…In the textbook [15] and the past references [16,17], the RTD curves obtained by water model and numerical simulation usually have a single flat peak, single sharp peak or double peaks [18][19][20][21]. Maybe these three types of peaks have some relations with each other.…”