Volume 58 (2018) Issue 3 Pages 422-430
In large-scale shaft furnaces, a new design of center gas supply device (CGSD) is proposed and its installation may affect solid flow in the furnaces. Due to its short history and lack of production experience, the solid flow in large-scale reduction shaft furnaces with CGSD is still unclear. In this work, three-dimensional solid flow is examined by discrete element method. The effect of CGSD on solid flow is studied including flow patterns, descending velocity, residence time distribution, interactive force and abrasive wear. The results show that the CGSD could affect the solid flow profile. Compared with the case without CGSD, in the case with CGSD installed, the descending velocity below the bustle zone is larger; the averaged residence time of solid phase is decreased; the dispersed plug volume fraction and dead volume fraction are decreased, but the well-mixed volume fraction increases; the averaged inter-particle force of solid is lower. On the other hand, the simulations show that the largest abrasion is observed on the surface of CGSD, and thus the CGSD lifetime should be taken into account in practice. The study provides a cost-effective tool to understand and optimize solid flow when the CGSD is installed in reduction shaft furnaces.