In order to improve the utilization of CaO based flux for hot metal desulfurization with mechanical stirring, the effect of a bottom inclination vessel on the hot metal desulfurization reaction was investigated in experiments with a water model and 70kg-scale induction furnace.
In the water model experiments, it was observed that the vortex generated by impeller rotation was inclined when using the bottom inclination vessel. The number of particles entrained into the water during stirring in the bottom inclination vessel increased by twice compared with that in the normal vessel.
In the hot model experiments, the desulfurization rate during 0-120 seconds after flux top addition increased by 3 times when using the bottom inclination vessel compared with that with the normal vessel. In the bottom inclination vessel, the estimated diameter of desulfurization flux entrained into the hot metal was half of that with the normal vessel.
The change in the water and hot metal flows was investigated by numerical simulation. In the bottom inclination vessel, the vertical downward flow velocity increased locally at the fluid-air interface. It is considered that entrainment of desulfurization flux into hot metal can be improved by this higher vertical downward velocity.
The bottom inclination vessel was tested in a commercial scale (350t) hot metal desulfurization vessel. Utilization of CaO based flux for desulfurization with the bottom inclination vessel increased by 1.25 times compared with the normal vessel.