The introduction of the appropriate size and precise location of flow control devices such as dam, turbulence inhibitor, etc., helps to modify the flow pattern and minimizing short circuiting and dead zone. Beside this, these also create the surface directed flow and maximize the residence time available for the flotation of inclusions and assimilation of the reaction products from the molten steel into the slag phase. These can be products of deoxidation, reoxidation, precipitation, emulsification and/or entrainment of refractory components into the melt and thus encompass both indigenous and exogenous inclusions. To this end, both the numerical and physical simulations were carried out mainly for three cases: a) in absence of flow control devices (i.e., bare tundish), b) in the presence of a dam, and c) with the application of turbulence inhibiting device (TID) and dam combination in the existing tundish configuration. The commercial CFD (computational fluid dynamics) package FLUENT ® was used to predict the flow field prevalent in the water model tundish at steady state, whereas in the experimental program, both Particle Image Velocimetry (PIV) techniques for flow measurements and tracer dispersion experiments for concentration measurements were applied in the present study. Among all types of configurations applied in the present study, a combination of TID with holesϩa dam work reasonably found to be an optimum configuration of the four-strand tundish regarding inclusion floatation. A superior strand similarity is also achieved in this configuration. Also the predicted time averaged horizontal and vertical components agreed withinϮ10 % with the experimentally derived ones.

An experimental study is carried out to determine the penetrability of impinging gas jets in molten steel baths of BOF and combined blown steelmaking. Depth and diameter of the depression produced by an impinging single jet or multi-nozzle jets are measured and correlated successfully with dimensionless momentum flow rate number. The equations are represented in the form of a nomogram by which the depth and diameter of the depression in a molten steel bath during the blow can be determined from easily available top blowing parameters.Eindringvermogen von auftreffenden Gasstrahlen in flussigen Stahl. Das Eindrinqverrnoqen von auftreffenden Gasstrahlen aus Ein-und Mehrlochdusen in flussiqen Stahl wird experimentell ermittelt. Eindringtiefe und Durchmesser der Auftreffstelle werden gemessen und mit dem dimensionslosen Impulsstrom korreliert. Die abgeleiteten Gleichungen werden in Form eines Nomogramms dargestellt, aus dem Tiefe und Durchmesser der Auftreffstelle wiihrend des Blasverlaufs unter Benutzung leicht zugiinglicher Aufblasparameter abgelesen werden konnen.

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Mechanism of slag carry‐over during drainage of metallurgical vessel is studied in a physical model. Vortex and drain sink formation are found to be the main mechanism of carry‐over of slag to the underlying vessel. Empirical equations are obtained to determine vortex and drain sink height under a wide range of draining conditions. Macroscopic mass and energy balance are used to determine vortex time. The vortex time is discussed in relation to the synchronization of the ladle change‐over time during sequence casting.