Steel Flow In Tundish Research Articles

Steel Cleanliness Depends on Inflow Turbulence Intensity (in Tundishes and Molds)

Economically, steel cleanliness is important. Cleaner steel contains fewer inclusions. Inclusions are removed, and thus cleanliness improves when steel is molten. Consequently, simulation of steel flow must be as accurate as possible. Steel flow in tundishes and molds is turbulent. In most turbulent flows, it is assumed that turbulence is generated inside the flow rather than entering with inflow. Due to this assumption, inflow turbulence intensity ( $$I_{\text{in}}$$ ) is sometimes not reported. If $$I_{\text{in}}$$ is reported, its values differ greatly among different papers. The present study shows, for the first time, that $$I_{\text{in}}$$ must be accurately specified because it affects steel cleanliness. In other words, the inclusions’ interaction (RTD curves), slag turbulence intensity and other factors concerning steel cleanliness depend on $$I_{\text{in}}$$ . This dependence is proved numerically by applying different $$I_{\text{in}}$$ s to steel flows in two industrial tundishes, two industrial molds and water models of a tundish and a mold. In addition to revealing this dependence, the results also disclose interesting facts regarding steel cleanliness. For example, this article illustrates that a tundish’s performance can change with $$I_{\text{in}}$$ . Therefore, a tundish’s performance depends on the design of the upstream devices as well as its own design.

Effect of Turbulence Inhibitor on the Molten Steel Flow in Tundish

The flow pattern and temperature distribution of molten steel in tundish were calculated by CFD and heat transfer method. Comparing the tundish flow field and the temperature field of empty packet and turbulence inhibitor installed, the role of turbulence inhibitor in tundish was analyzed, and the advantages and disadvantages of turbulence inhibiter were illuminated. The results show that: the turbulence inhibitor can eliminate the short circuit flow at tundish bottom, stabilize flow, and homogenize molten steel composition; but the turbulence inhibitor can consume energy of molten steel, and reduce the temperature of molten steel in the tundish. Without the turbulence inhibitor, the surface minimum temperature is far from the narrow corner, it is not easy to knot cold steel; installing turbulence inhibitor can raise the molten steel temperature near inlet, steel flow will scour inlet refractory intensively, service life of which shortens.

Numerical Simulation of Flow Field in the Tundish with Two Outlets

According to the operating parameters of continuous casting tundish in a steel mill, the flow patterns of liquid steel in tundish were studied by the method of numerical simulation. Changing the flow orifice area of slag wall, to simulate and calculate the influence of slag wall on the flow field in tundish. Through calculating the steel flow vector, to analyze the uniformity of steel flow in tundish, by calculating the inclusions distribution to analyze the effect of blocking slag wall holding inclusions. The simulation results show that: the slag wall can obviously deduce the short circuit flow of steel liquid in tundish bottom. With the flow orifice area is reduced, and the turbulence brisk between two slag walls, and liquid surface is easy to roll; the ability of slag wall holding inclusions enhances, but too small flow orifice area will prompt inclusions passing the slag wall.

Optimization of Liquid Steel Flow in an Industrial Tundish

A computational fluid dynamic (CFD) model was developed to study the fluid flow phenomena taking place in an industrial tundish. Numerical results showed spatial distributions of the velocity vectors, the residence time and fields of turbulence kinetic energy. Selected computer simulation results were validated with experimental data. The effect of the impact pad and interior dams on the hydrodynamics of liquid steel flow were studied numerically and optimized to reduce the fraction of dead volume zones and augment nonmetallic inclusions to float into the slag. A novel design of a turbo-stopper was proposed and its function to decelerate the ladle shroud jet and direct the flow back to reduce slag entrapment was discussed. Such numerical results improved our understanding of the hydrodynamics of liquid steel flow in the tundish and contribute to an optimized operation.

Modeling Study of the Influence of Subflux Controller of Turbulence on the Molten Steel Flow in Tundish

The objective of the study is to diagnose the current condition of the two-strand tundish. The investigated object is a “T”-type tundish. The nominal capacity of the tundish is 7.5 tonne of liquid steel. By the mathematical simulation, fluid flow and heat transfer of molten-steel in a tundish of a billet caster under different conditions (bare tundish and tundish with flow control device) are analyzed. Three variants of subflux controller of turbulence configurations in the tundish are tested. Numerical simulations of are carried out with the finite-volume commercial code FLUENT using the realizable k- turbulence model. Liquid steel velocity, temperature, turbulent kinetic energy and Residence Time Distribution (RTD) characteristic have been obtained as a result of mathematical calculations. The RTD curve is used to estimate the different volumes such as plug volume, dead volume and mixed volume inside the tundish. The ratio of mixed to dead volume, which indicates the mixing capability of a tundish, is estimated.

Water Model Study on Convection Pattern of Molten Steel Flow in Continuous Casting Tundish.

Natural convection will obviously influence the liquid steel flow in continuous casting (CC) tundish, which cannot be neglected in tundish metallurgical process. Through the theoretical analysis, the dimensionless number, Gr/Re 2 , is adopted to determine the convection pattern in tundish system. Validity of this criteria in a reduced scale water model are also discussed in this paper. Non-isothermal water model experiment with the temperature variation of inlet stream, has been simulated to see the effect of temperature variation of ladle stream. The convection pattern of molten steel flow in continuous casting tundish is also studied numerically by using the commercialized computational fluid dynamic (CFD) software package, CFX4. From the results of theoretical analysis, physical and mathematical model simulation, it can be stated that the convection pattern of molten steel flow in tundish is controlled by the combined nature convection and forced convection.