Numerical study of gas-solid two-phase flow in the snout of continuous hot-dip galvanizing process

Abstract

In the hot-dip galvanizing process for strip steel, zinc vapor oxidizes and forms zinc ash in the snout. Given that the snout connects the annealing furnace, the zinc ash will return to the annealing furnace with the gas, affecting the upstream process. The gas-solid two-phase flow regularity in the snout is the key issue for zinc ash control. In this paper, the snout of a hot-dip galvanizing production line was taken as the physical model. The two-phase flow was simulated by the Euler-Lagrange method and the zinc ash particles were simulated via the discrete phase model (DPM). The results show that several vortex regions exist in the snout due to the forced convection caused by the moving strip and changes in flow channel sizes. There exist differences in the movement of zinc ash with different diameters. Small zinc ash has a strong tracking performance with the gas. Large zinc ash is easy to remain in the snout. In addition, orthogonal analysis was conducted to determine the optimal parameter combination. The research results provide theoretical guidance for the operation scheme of the gas circulation system.