Energy conservation and heat transfer enhancement for mixed convection on the vertical galvanizing furnace

The alloying temperature is an important parameter that affects the properties of galvanized products. The objective of this study is to explore the mechanism of conjugate mixed convection in the vertical galvanizing furnace and propose a novel energy conservation method to improve the soaking zone temperature based on the flow pattern and heat transfer characteristics. Herein, the present study applied the k-? two-equation turbulence model to enclose the Navier-Stokes fluid dynamic and energy conservation equations, and the temperature distributions of the steel plate and air-flow field in the furnace were obtained for six Richardson numbers between 1.91 ? 105 and 6.30 ? 105. In the industrial practice, the side baffles were installed at the lateral opening of the cooling tower to alter the height of vertical flow passage, which affected the Richardson number. The results indicate that the Richardson number of 2.4 ? 105 generated the highest heat absorption and maximal temperature in the steel plate due to the balance between natural and forced convection. Furthermore, the results of the on-line experiments validated the simulation research. The method enhanced the steel plate temperature in the soaking zone without increasing the heat power, thereby characterizing it as energy conservation technology.