A transient model for submerged entry nozzle clogging: A coupled CFD and DEM approach

Submerged entry nozzle (SEN) clogging has been a long-standing problem, especially for casting Al and Cebearing steels. The clogging is believed to be the accretion of non-metallic inclusions on the nozzle wall. In this study, the behavior of every single inclusion is numerically monitored using the CFD-DEM approach, including their deposition on and detachment from the nozzle wall. The cavity and the van der Waals forces are the main components of the adhesion force. It is found that clogging is a self-accelerating process, and it is very dependent on the adhesion force between inclusions and/or between inclusions and the nozzle wall. Due to a more significant adhesion force between Ce2O3 inclusions, less clog fragmentation happens when casting Ce2O3containing steel. The initial deposition position of Ce2O3 inclusions is lower in the nozzle than that of Al2O3 inclusions; however, the general clogging trends are similar for the two cases with monosized inclusions.