Dripping Liquid Metal Flow in the Lower Part of a Blast Furnace

Abstract

Numerical simulation of blast furnace phenomena has significantly contributed to the better understanding of iron making process. Recent interest on minimizing fuel consumption and reducing environmental problems have also benefitted from the development of comprehensive simulation models based on physical principles. One of the under-developing fields, however, is related with the internal phenomena in the lower part of the blast furnace under the cohesive zone, where the liquid phase of metal and slag flows downward over the bed of solid coke particles. Hot flow of sluggish liquid phase is further complicated by the chemical reactions including the transfer of silica into the silicon in the hot metal. Silica enters the furnace as a constituent of coke ash and ferrous gangue, and exits as either molten silica in slag or dissolved Si in the hot metal. Silica reduction is an endothermic reaction, which would alter the heat transfer in the lower furnace, thus affecting the hot metal temperature. Effective flow in the dripping zone is important for stable operation of the blast furnace with high productivity of iron. Study of the liquid flow behavior and secondary reactions in a packed bed allows to investigate the effect of various operational changes in the dripping zone. In this research, a systematic numerical approach for the liquid flow is presented where the flow behavior is solved along with heat transfer associated with physic-chemical reactions among representative components.