Influence of Variable-Diameter Structure on Gas–Solid Heat Transfer in Vertical Shaft Cooler

Abstract

In order to improve the heat transfer between high-temperature sinter and cooling gas in a vertical shaft cooler, a new furnace type with variable-diameter structure was proposed, and the influence of variable-diameter structure on gas–solid heat transfer in vertical-shaft cooler was studied by CFD-DEM coupling method in the current work. The results show that variable-diameter structure can increase the quantity of low-temperature sinter as well as the outlet cooling gas temperature, and can improve the uniformity of sinter and cooling gas temperature along the width, at the cost of significantly increasing the cooling gas pressure. By changing the parameters of the variable-diameter structure, it was found that a smaller width of the vertical section or a larger angle of the contraction section led to a better sinter–gas heat transfer. The influence of vertical section width on cooling gas pressure was more obvious. It is suggested that when designing and using the vertical shaft cooler with variable-diameter structure, consideration should be given to the effect of sinter–gas heat exchange and the pressure of cooling gas. Furthermore, the occurrence of material blockage and excessive equipment height should be avoided.