Analysis of critical slag entrapment speed at the steel–slag interface

Based on particle image velocimetry (PIV) technology, the process and flow field characteristics of slag entrapment under the condition of critical slag entrapment are investigated by water model. The change of interface flow field at the slag entrapment process from the occurrence to end of critical slag entrapment is analysed, and the influence of kinematic viscosity of slag on critical slag entrapment velocity is quantitatively analysed. The results show that the kinematic viscosity of slag has an important influence on slag entrapment. The critical blowing flow and critical speed increase with the increasing of the viscosity. Based on the law of conservation of energy and the traditional theoretical calculation models, an improved formula for critical slag entrapment speed is proposed in this study, which further considers the thickness and viscosity of the slag.