Numerical analysis of the carbon-containing pellet direct reduction process with central heat transfer enhancement

• 1、School of Energy and Power Engineering, Chongqing University, Chongqing 400044, P.R. China
• 2、Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400044, P.R. China

Abstract：A coupling model of carbon-containing pellets reduction process with intermediate media in its center was established, effects of porosity and chemical heat during the reduction process were considered. The model was verified by experiments from reference.With the pellet radius R0=11mm, the influence ofintermediate spherical medium radius r0, the offset position of the medium ξ, and the materials used on the overall pellet reduction process were analyzed. Results show that the presence of a spherical medium in the pellet center can increase the temperature inside the pellet, leading to be more advantageous for reduction. With the increasing of the medium radius r0,it is more favorable for the reduction process,since the spherical medium is more efficient for heat conduction. With the increasing of the offset value ξ, the spherical medium acting as heat-conducting material can allow the heat transferred to the pellet insidefaster, which is also more favorable to the reduction process. In addition, when the spherical medium has a smaller effective volume heat capacity ρCp and a larger thermal conductivity k, it is more favorable for pellet reduction process too.

Keywords： rotary hearth furnace carbon containing pellet direct reduction enhancement of heat transfer numerical analysis