Work

Numerical simulation study on dew point control in the local area of a vertical continuous annealing furnace

Year: 2025

Type: article

Abstract: : To address the issue of uneven humidifying gas distribution in continuous annealing furnaces, which affects the quality of strip galvanizing, a mathematical model of humidifying gas convection and diffusion within the furnace was developed. Experimental and numerical analyses of flow characteristics in humidifying tubes were conducted, focusing on nested double-layer equalizing tubes and oblique single-layer equalizing tubes. The effects of humidification tube design on gas convection and diffusion uniformity were compared, and the coupled influence of heat shield and partition wall structures on heated gas behavior was also evaluated. Results indicated that the nested double-layer equalizing tube significantly reduced airflow segregation and improved atmosphere uniformity, enhancing humidification performance when combined with optimized furnace architecture. Transient simulations and parameter optimization identified the optimal configuration as “improved furnace structure + nested double-layer upward injection equalizing tube.” This combination reduced the standard deviation of the dew point to 3 °C and increased the average dew point uniformity index to 0.90.

Source: Thermal Science and Engineering Progress

DOI: 10.1016/j.tsep.2025.104448