Flow properties of two-component metallized pellets in waste heat recovery drum cooler

Abstract

In order to improve the waste heat recovery efficiency of high-temperature metallized pellets and save spraying cooling water, a waste heat recovery drum cooler with cooling water channel was creatively proposed for waste heat recovery. Due to the flow properties of two-component metallized pellets impact its heat transfer properties, the DEM (Discrete Element Method) and soft ball model were used to investigate the flow properties of two-component metallized pellets in the waste heat recovery drum cooler. By comparison with experimental data, the calculated values for the flow properties of two-component metallized pellets were in good agreement with the experimental values. The results show that the two-component metallized pellets are predominantly mixed and separated as they flow from top to bottom, with the large metallized pellets surrounding the small metallized pellets. The axial velocity and total velocity are significantly influenced by the dip angle and rotating velocity, and the filling rate has a substantial impact on the contact number. As the dip angle increases from 1° to 5°, the axial velocity and total velocity increase by 382.86 % and 333.33 %, respectively. With the rotating velocity from 1.2 r/min to 3.2 r/min, the axial velocity and total velocity increased by 175.00 % and 161.82 %, respectively. As the filling rate went from 1.5 % to 15 %, the contact number increased by 68.27 %. The axial velocity/total velocity of the two-component particles varies from 0.893 to 0.996 during the change of the dip angle, rotating velocity and filling rate. This shows that the axial velocity always makes up a large part of the total velocity. By efficiently organizing the movement of two-component metallized pellets, it is possible to increase the heat transfer efficiency, and it can also eliminate the pollution of cooling wastewater caused by the conventional spray rotary drum cooling method.