Numerical investigation of gas-solid heat transfer process in vertical tank for sinter waste heat recovery

In the present paper, a three-dimensional mathematical model is established on the basis of the porous media theory and the local thermal non-equilibrium model, to investigate the gas solid heat transfer in sinter bed layer of vertical tank. The reliability of mathematical model is verified through the comparison of calculated results with the experimental results according to the homemade experimental setup. Numerical simulations are conducted to examine the influences of different structural and operating parameters on the air and sinter temperatures in sinter bed layer. Furthermore, an optimal combination of each parameter is determined through the orthogonal experiment for improving the outlet exergy of cooling air. The results show that the outlet air and sinter temperatures decrease with the air flow rate increasing. Decreasing the inner diameter and height of cooling section, or increasing the particle diameter, the outlet air temperature decreases and the outlet sinter temperature increases. Based on the sinter annual output of 3,900,000 tons for 360 m2 sintering machine, the suitable structural and operating parameters of vertical tank are 150 kg/s for the air flow rate, 0.015 m for the sinter particle diameter, 10 m for the inner diameter of cooling section and 8 m for the height of cooling section.