In blast furnaces, the erosion of refractories in the hearth is widely considered to be the main limitation of the attainable campaign length. Therefore, numerical investigations related to the hot metal flow have proven valuable to enhance the understanding of refractory wear mechanisms as the hearth flow is inaccessible for measurements. Within the scope of the present work, a hearth model describing the transient, multiphase flow at an industrial scale has been developed based on the CFD solver ANSYS Fluent ®. A novel approach has been proposed for modelling the inflow of slag and hot metal into the hearth combined with an adjustable boundary condition to describe the clogging of the taphole. In addition, dedicated sub-models to compute energy and carbon transport including carbon dissolution have been implemented. The hearth model has been applied to investigate different coke bed structures employing the hearth domain and process conditions from an industrial blast furnace. It has been found that a thermal stratification is present in the hearth. Depending on the coke bed characteristics, a zone of low-temperature, carbon-rich, stagnant hot metal prevails at the hearth bottom while the region above is determined by circulation effects due to natural convection. During tapping, the flow adjacent to the taphole is controlled by forced convection whereas the flow opposite to the taphole is driven by natural convection. In between the taps, the hearth flow is driven by natural convection effects which are strongly related to refractory cooling. Furthermore, the transient evolution of tapped liquid temperature has been obtained in numerical simulations and it has been compared to measurements conducted at industrial blast furnaces.weiterlesen