Single strand continuous caster tundish furniture comparison for optimal performance

Abstract

Analysis of a single strand 36 t thin slab caster tundish has been conducted with different sets of furniture using a three-dimensional computation fluid dynamics model taking heat losses into account. Five distinct and optimised cases and a base case were used for simulation. The cases were built considering tundish furniture that is readily and economically available and provides ease of maintenance, thus targeting an optimal set of furniture. The performance of different sets of furniture was assessed based on residence time parameters like plug volume fraction, mixed volume fraction, dead volume fraction, etc. Other performance indicators used in the analysis were temperature distribution, observing cold spot, surface velocity and nature of flow in the tundish. Insight from the base case reveals the desired flow characteristics that help to achieve the target performance. Inferred results suggested the use of a turbulence inhibitor in combination with a dam as the optimal set of furniture. Use of a non-isothermal model is important, as it was found that even a small change in temperature (2?3uC) plays a vital role in the fluid flow inside the tundish.

Numerical Investigation of Unsteady Molten Steel Flow and Inclusion Behavior in the Tundish in the Ladle Change Period

“…The decrease of the molten steel volume seemingly acts as a plug flow during ladle change. At the start of pouring from the new ladle (Phase [3]), the well-mixed volume increases sharply. This indicates the existence of a strong turbulent flow caused by a large inflow.…”

“…Thus, the amount of remaining molten steel in the tundish gradually decreases. The third phase (Phase [3]) is the start of pouring from the new ladle. This starting phase occurs from t=3.5 minutes to t=4.0 minutes.…”

“…1,2) Sahai's method is useful in quantitatiion of the flow characteristics of tundishes, and thus is commonly used by the authors. [3][4][5][6][7][8] It has also been reported that the characteristic volumes, in particular the plug-flow volume, have a relation to inclusion removal performance in steady state tundishes. 9,10) Particle injection is also a popular method for direct investigation of inclusion removal performance in tundishes.…”

Performance Optimization of a Six-Strand Tundish

“…They concluded that the tendency of getting trapped at the top surface is more for inclusions with higher diameter as compared to that for smaller diameter inclusions. Singh et al [2] studied the performance of a tundish possessing different sets of furniture using the residence time curve in a single-strand tundish. Zhang et al [3] investigated the inclusion removal with the help of gas bubbling and concluded that bubbling affects large particles but tendency of floating out of small particle increases due to bubbling.…”

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

“…The fluctuation of temperature influences the viscosity and density of the liquid steel, and thus also its flow. The stream patterns occurring in the tundish working space in the turbulent motion system form hydrodynamic states which are characteristic of given tundish furniture [9][10][11][12][13]. In addition, a parameter varying during the course of the CSC process is the casting speed, which is dependent on the casting dimensions, steel grade and the metallurgical length of the plant, including the cooling system.…”