Discrete particle simulation of gas-solid flow in a blast furnace

Gas-solid flow plays a dominant role in the multiphase flow in an ironmaking blast furnace (BF), and has been modelled by different approaches. In the continuum-based approach, the prediction of the solid flow pattern remains difficult due to the existence of the stagnant zone in the BF lower central part. This difficulty has recently been shown to be overcome by discrete particle simulation (DPS). In this work, the DPS is extended to couple with computational fluid dynamics (CFD) to investigate the gas-solid flow within a BF. The results demonstrate that the DPS-CFD approach can generate the stagnant zone without global assumptions or arbitrary treatments. It confirms that increasing gas flow rate can increase the size of the stagnant zone, and in particular changes the solid flow pattern in the furnace shaft. More importantly, microscopic information about BF gas-solid flow, such as flow and force structures that are extremely difficult to obtain in continuum-approach or experiments, can be analysed to develop better understanding of the effect of gas phase, and the underlying gas-solid flow mechanisms.