Effect of refractory properties on initial bubble formation in continuous-casting nozzles

A water model has been applied to investigate initial bubble behavior using specially-coated samples of porous MgO refractory to simulate the high-contact angle of steel-argon refractory systems with different permeabilities. Air is injected through the porous refractory and travels through many inter-connected pores to exit the surface through active sites. An active site is a pore where bubbles exit from the surface of the porous refractory. The effect of refractory properties has been investigated in both stagnant and downward-flowing water. The number of active sites increases with increasing gas injection flow rate, permeability, and velocity of the downward-flowing water, and lower contact angle.