Reversible Reaction Kinetics Model for the Formation of Dross Particles in Hot-Dip Galvanizing Lines

Dross particle formation in the hot-dip galvanizing zinc bath and dross build-up on the sink rolls can cause surface defects on the steel-strip. State-of-the-art approaches in zinc bath dross reaction modeling in CFD simulations rely on thermodynamics considerations, where the formation or dissolution of dross occurs instantaneously whenever the system is out of equilibrium. These approaches totally ignore the finite time required for the reaction which leads to an imperfect representation of the actual spatial distribution of the concentration fields. To overcome this drawback, a reversible kinetics model for the Fe_2Al_5Zn -phase dross particles is presented that is coupled to species transport equations. Model parameters were determined by fitting with innovative lab-scale GalvaLIBS experiments.