Experimental Investigations on Gas Stirred Water Ladle Models

The global steel industry, serving as a fundamental cornerstone of modern civilization and essential to infrastructure, manufacturing, and technological advancements, continually strives to meet the increasing demand for high-quality steel. Achieving this goal necessitates ongoing innovations in the realm of secondary steelmaking processes, which have become indispensable for refining steel properties after the primary production phase. Ladle metallurgy provides a means to actively control the steel’s composition and properties. However, the intricacies of molten steel flow within a ladle have been challenging to decipher under the extreme conditions it presents. Gas stirring is an essential component of this procedure, where inert gas is introduced into molten metal to ensure consistent mixing, thereby homogenizing the chemical composition and eliminating inclusions. This method improves the quality and mechanical properties of steel while reducing defects in the final product. The turbulence created by gas injection enhances the interaction between molten steel and slag, particularly through the formation of the slag eye, facilitating chemical reactions and impurity removal. To deepen our comprehension of these complex processes, extensive research employing dynamically scaled water models has been undertaken to comprehensively grasp the underlying mechanisms in ladle metallurgy.

In this thesis, we have developed dynamically scaled water ladle models, to replicate the stirred flow field and address the intricate issue of controlling micro-inclusions. In the first experiment, an advanced Particle-Tracking-Velocimetry system of the Shake-the-Box was implemented on a cylindrical water ladle model, to resolve the three-dimensional flow field inside a 6 × 6 × 2 cm domain. In total, eight conditions of compress air injections were investigated. Then, a two-dimensional water ladle model tank was scaled to focus on flow-induced slag entrainment at the water-oil (steel-slag) interface. Our endeavor is dedicated to improving the quality and consistency of steel, thereby making a significant contribution to the steel industry’s relentless pursuit of excellence.