Porosity distribution of moving burden layers in the blast furnace throat

The porosity distribution of burden layers in the blast furnace (BF) plays an important role for the gas distribution and gas–solid two-phase interaction. In this work, the porosity distribution along the radial and vertical directions of the BF throat was studied by the discrete element method combined with some experimental verification. The simulated radial porosity distribution of coke burden layer shows general agreement with experimental findings, which in practice depends on the charging matrix. When a layer of burden moves from the top to the bottom, its structure will become more compact, so the porosity will decrease. However, the changes occur while 4–5 new layers are built on top of the layer in question, after which the porosity stabilized at an equilibrium point. For the full burden bed, the porosity of coke layers is larger than that of ore layers, but both layers have larger porosity than mixed layer formed by sinter charged on coke, especially when the particle size difference between ore and coke is large. Graphic abstract: [Figure not available: see fulltext.].