Investigation of Flow Characteristics in a Six‐Strand CC Tundish Combining Plant Measurements, Physical and Mathematical Modeling

Abstract

The tundish plays a major role in the continuous casting process. The flow in a tundish has a very substantial effect on the quality of the final product and on efficient casting conditions. Efforts are being made worldwide to obtain the most favourable shape of tundish interior by using dams, weirs and gas curtains. The aim of these flow control devices is to reduce the dead zone areas and improve the conditions for the separation of non‐metallic inclusions. Numerous model studies are being carried out to explain the effect of the tundish working space shape and steel flow conditions on the inclusions floating processes. The presented article shows the results of investigations performed to obtain the mass exchange characteristics in the investigated tundish. The measurements were done directly at the steel plant during normal working conditions. By controlling the changing content of manganese in steel, the residence time distribution (RTD) characteristics were acquired. The RTD characteristics are also obtained with a water model of the tundish with dimensional scale of 1:3. Parallel to the water model, numerical simulation based on mathematical modelling of fluid flow, relying on the system of differential equations, is employed in the research work. Numerical simulations were carried out with the finite‐volume commercial code FLUENT using the standard k‐ε turbulence model. The primary purpose of the investigations carried out is to present the characteristics describing the transitory zone in a six‐strand tundish. It is shown that the F‐curve, describing the transitory zone, can be obtained by using different measurement techniques. Tracer concentration characteristics for the model of tundish obtained from both modelling techniques ‐ physical as well as numerical ‐ are very similar.

Investigation of the Flow Structure in the Tundish with the Use of Rans and Les Methods

“…Presented studies are continuation of the previous research performed with tundish water model and RANS calculations [22]. …”

“…There are areas with a high level of turbulence (shroud and nozzles), and areas with the laminar movement. Since most of numerical researches performed so far are done with RANS method (Reynolds-averaged Navier-Stokes equations), for turbulence modeling, the standard [6,18] or realizable [19,20] k-ε models are mostly used, rather RSM [21,22] (Reynolds Stress Model). In numerical modeling, a choice of a proper turbulence model is crucial as it has a great impact on the flow structure of the fluid in the analyzed test facility.…”

Method for Determining the Time Constants Characterizing the Intensity of Steel Mixing in Continuous Casting Tundish

“…Function E(t) and F(t) are the most common RTD functions used to describe the character of steel flow in tundish of CC machine [5,6,[11][12][13][14][15][16][17].…”

Experimental Methods of Validation for Numerical Simulation Results on Steel Flow through Tundish

“…The view of the test stand of the continuous casting device is presented in Fig.1. By using the physical model, there were performed research tests based on visualization and tracer concentration distribution was determined in the form of Residence Time Distribution (RTD) characteristics (of type F [10,11]). Aqueous solutions of KMno 4 [12] and NaCl are used as markers in the model.…”

“…In order to perform direct comparison of results derived from numerical simulations and experiments, the marker concentration and times were converted into dimensionless characteristics, utilizing for this purpose appropriate recalculations [10]. Figure 3 presents dimensionless RTD characteristics of F type for experimental tests and numerical (CFD) simulations.…”