<i>In-situ</i> Analysis and Numerical Study of Inclusion Distribution in a Vertical-bending Caster

Abstract

Based on a fast-detection platform (FDP) founded by us, an in-situ measurement of inclusion distribution in slab is successfully performed. The inclusion distribution is obviously asymmetry and non-uniform. Specially, due to the structure differences in the vertical and bending part of a slab caster, the inclusion distribution in these two parts are quite different: In the vertical part, the inclusions entrapped in the outer arc is much more than that in the inner arc, while in the bending part, the inclusions entrapped in the outer arc is a little less than that in the inner arc. Large inclusions are tend to be found near the surface, and sometimes in the center, but they're very few. Then in order to interpret the inclusion distribution in practical measurements, a new LES model is established using Euler-Lagrange approach. A new entrapment criterion is also defined to calculate the entrapped inclusions. Big inclusions are tend to float up to the mold top, and aggregate near the outer arc, which can explain the differences of inclusion distribution in the vertical part; Smaller inclusions are easier to flow deep into the mold, and become clusters when they're getting near, which can explain the big inclusions in the central part. What's more, the drag effect of bending slab is proven to be responsible for the differences of inclusion distribution in the bending part. This mathematical model is helpful for understanding the inclusion movements in slab.

Modeling of the Effect of the Gas Flow Rate on the Fluid Flow and Open‐Eye Formation in a Water Model of a Steelmaking Ladle

“…The dimensions of the current water model, densities of water, and oil used in the current work are substituted in the Equation for calculating the dimensionless open‐eye area. Li et al also measured the dimensionless open‐eye area using the model developed by Krishnapisharoday et al The results of the current work are also shown in Figure . This indicates that the open‐eye area obtained by the present model may be somewhat higher compared to the literature data.…”

“…Nondimensional eye area versus modified Froude number; K&I = Krishnapisharody and Irons and L&L = Li and Li …”

“…Studies related to studying the open‐eye in a gas‐stirred ladle through physical modeling and numerical simulation have been performed extensively in the past three decades. Yonezawa and Schwerdtfeger carried out cold model measurements using mercury and silicone oil to represent liquid metal and slag, respectively, for investigating the open‐eye size in the ladle.…”

“…From the results, it was found that the shape and size of the open‐eye are influenced greatly by the gas flow rate and that empirical correlations are not able to fully describe the dynamic flow behavior in the gas stirred ladle. Recently, Zhongqiu et al studied the open‐eye size in industrial and a one‐third scale water model for different gas flow rates. It was found that the open‐eye area increases approximately linearly as the gas flow increases.…”

“…The results predicted by the model agreed with the experimental results. Li et al also developed a three‐phase mathematical model based on Large Eddy Simulation (LES) coupled with Discrete Particle Modelling (DPM) and the VOF model to investigate bubble movement and slag layer behavior during gas stirring in the ladle. The predicted simulation results of the formation and closing of the open‐eye qualitatively agreed with the experiments.…”