Modeling of Two‐Phase Flow in Blast Furnace Trough

Almost 95% of the world's hot metal production is from blast furnaces, reaching a production of 1.2 billions tons in 2018 according to the World Steel Association. The trough is an important equipment within the blast furnace production process, promoting the separation between hot metal and slag after casting. However, the flow pattern inside the runner is understudied due to its complexity. Due to the turbulence in the trough during the casting, there is metal loss in the slag and also slag entrainment in the hot metal. The metal loss in the slag is the most critical situation as it directly affects the efficiency. The influence of flow rate as well as of geometrical parameters on the flow pattern inside the runner is analyzed by physical and numerical simulation. In the physical simulations, particle image velocimetry (PIV) as well as dye injection using HD cameras and residence time distribution (RTD) curves are used to characterize the flow. These techniques allow to validate the mathematical model created in CFX‐Ansys. This work stresses the changing flow features as the slag–metal ratio changes during the casting operation and the role of geometry as far as metal separation from the slag is concerned. Metal losses during the blast furnace casting operation are due to dispersion of metal droplets in the slag. The economical impact of metal losses is important because large tonnages are involved. Metal losses change as a function of slag–metal ratio of flow rates as well as geometry of the runner. These aspects are highlighted by physical and mathematical modeling.