Mathematical modeling of multiphase system in tundish of continuous casting machine: theory and experiments

The most complex task is the description of non-metallic inclusions behaviour in various zones of the tundish molten bath. In this case the most important feature of simulation is the prediction of conditions, under which large-sized non-metallic inclusions of 20-100 μm and over, are captured by convective flows and transferred to the liquid steel surface. Mathematical and physical modelling has demonstrated that the upfloating of large-sized non-metallic inclusions is substantially enhanced with argon purging into a molten bath via a dedicated plug placed at the tundish bottom. The blowing efficiency through this plug depends heavily on the argon flow rate, bubbles diameter, steel residence time in the tundish, etc. It was proved that the main constraint for gas flow rate amount blown into a tundish molten bath, is the swirling of steel and slag in the area of argon bubbles ingress into the air. At the same time, small-sized particles of the covering slag are entrapped into the liquid bath by downward convective flows.Keywords: mathematical FEM modeling; physical modelling; caster tundish; vector component; steel flows; gas purging; mass- and heat-transfer processes