Prediction of zinc evaporation in the snout of high-temperature hot-dip zinc-aluminum-magnesium coating line

The internal flow field of snout affects the quality of hot-dip zinc products significantly. The prediction of zinc evaporation is a key issue of analyzing the atmosphere flow in the snout. In this paper, simulations of the atmosphere flow with zinc evaporation considered are carried out in the snout of a high temperature hot-dip zinc-aluminum-magnesium coating line. In order to eliminate the false diffusion in numerical calculation of zinc evaporation, a strategy of high-order scheme combined with local orthogonal grids at the zinc vaporization boundary is proposed. The simulation is validated by available experimental data. The effects of operation parameters such as the temperature of snout wall, the width and the speed of the strip on the zinc vapor flow are studied. It is found that with the increased temperature gradient between the snout wall and strip wall, the concentration of zinc vapor in the snout is also increased. Therefore, the method of heating the snout wall can reduce the temperature gradient between the snout wall and strip wall, so it is beneficial to reduce the evaporation of zinc liquid in the snout.