Simulation of non-metallic inclusion deposition and clogging of nozzle

Abstract

Motion of non-metallic inclusions (NMIs) in molten steel and deposition of them on nozzle wall leading to clogging are simulated using a two-way coupling model. In this model different steps of clogging have been considered including transport of NMIs by turbulent melt flow towards the nozzle wall, adhesion of the NMI on the wall, and formation and growth of clogging material by the NMI deposition. The model is used to simulate clogging in a pilot scale device. The results show that the model reproduces these clogging steps well until complete blockage of the flow path in the nozzle. It is found that clog growth step plays critical role for prediction of the clogging process and understanding melt flow and NMI behaviors during the process. Without implementation of this step, unrealistic melt flow rate is obtained leading to incorrect particle deposition rate. In addition, if the clog growth is ignored, distribution of deposition material becomes more uniform with overestimated amount of total deposition mass.