Effects of burden layer porosity on the reduction reaction of a blast furnace Lump zone

The ironmaking blast furnace (BF) is a counter-current chemical reactor. The porosity distribution of burden layers in BF plays an important role for the gas distribution and gas–solid two-phase interaction. In this research paper, to analyze how porosity distributions affect gas velocity, gas temperatures and reduction, the different porosity distributions were investigated using three distinct processes by numerical models. The results showed that the change of porosity along the radius direction had a more obvious effect than along the height direction. When the porosity is exponentially distributed, the gas velocity was allowed a great development, promoting the gas temperature and reduction. Besides, in the lower part (height = 1/3H), with increasing porosity, the gas velocity increases by 30% and reduction by 25%. In the middle part (height = 2/3H), the gas velocity is increased by 30%, the gas temperature is increased by 200 °C, and the reduction is increased by 20%.