The model incorporates turbulent fluid dynamics, chemical reaction kinetics and heat and mass transfer. Key features include the use of the k-epsilon turbulence model, incorporating the effect of particles on turbulence, and the four-flux model for radiative heat transfer. Numerical computations have been performed for the turbulent recirculating flow field of a gas jet in a confined cylindrical system. The effects of inlet conditions and various correlations for the dissipation rate of turbulent kinetic energy have been tested. A new correlation equation for the latter, yielding the best results, was obtained. To predict the behavior of a particle-laden gas jet under flash-smelting conditions, model predictions have been obtained for various inlet conditions, feeding modes of the primary gas stream at the inlet, particle sizes, degrees of particle loading, and values of oxygen enrichment. In the case of axial feeding of particles, the presence of solid particles causes the axial velocity of the gas phase to be greater near the centerline and less in the outer region than in a single- phase gas jet. More uniform distribution of particles is obtained by introducing a strong radial velocity of the distribution air at the inlet. Model predictions have been performed and compared with experimental data from an outokumpu pilot flash furnace. Reaction of sulfide particles is almost completed in the upper zone of the furnace within about 1 m of the burner and the double-entry burner system with radial feeding is better than the single-entry burner system.
Ph.d. Thesis, Univ. Utah, 1988, 183 PP.