Numerical Study on Desulfurization Behavior During Kanbara Reactor Hot Metal Treatment

The hot metal desulfurization in Kanbara Reactor (KR) metal treatment was simulated in this study via a transient-coupled 3D numerical model of the two-phase flow, heat transfer, and particle motion desulfurization processes. The KR impeller stirring was described via the multiple reference frame model. The volume of fluid approach was employed to capture the air-hot metal interface. The particle motion and aggregation were defined by the two-way coupled Euler–Lagrangian method. A desulfurization kinetic model was simultaneously introduced to represent the sulfur mass transfer rate. The effect of the initial diameter of desulfurizing agent (DA) particles on the desulfurization efficiency was quantitatively assessed. The lowest sulfur content was observed in the impeller vicinity and the highest one in the inactive colder liquid metal at the vessel bottom. With the DA particle initial diameter reduction from 3.0 to 0.5 mm, the overall desulfurization rate was increased from 83.2 to 97.1 pct. Insofar the specific surface area of smaller particles exceeded that of larger ones, they had higher motion velocities and heating rates, creating a greater reactivity for the desulfurization. However, desulfurization at the vessel bottom was only slightly enhanced using smaller DA particles, so the overall improvement did not exceed 20 pct. Further enhancement is envisaged by refining the impeller design and particle-adding technique.