Modelling of liquid flow in the blast furnace. Theoretical analysis of the effects of gas, liquid and packing properties

Molten iron and slag flows play a critical role in the blast furnace lower zone, transporting mass and energy, whilst impairing and redistributing gas flow. In turn, molten iron and slag undergo physical and chemical changes, and are redistributed radially during descent to the hearth. Using a 'force-balance' approach, the flows of liquid in the blast furnace were characterised. A consistent set of equations describing liquid holdup, gas-liquid interaction and solid-liquid interaction was developed with reference to previous experimental studies and furnace conditions. The model accounts for the effect of gas, liquid and packing properties on liquid flow, as well as the effect of liquid on gas flow. Interaction between metal and slag phases occurs via a shared gas flow field. Importantly, the model can be applied under both countercurrent and non-countercurrent conditions, where gas can either hinder or enhance liquid flow.