CFD Modelling of Combustion Behaviour in Slag Fuming Furnaces

A thin slice CFD model of a conventional tuyere blown slag fuming furnace has been developed in Eulerian multiphase flow approach. The model was developed by coupling CFD with kinetics equations developed by Richards et al. for a zinc fuming furnace. The model integrates submerged coal combustion and chemical reactions with the heat, mass and momentum interfacial interaction between the phases in the system. The model predicts the velocity, temperature field of the molten slag bath, generated turbulence, vortex and coal utilization behaviour from the slag bath. Highest coal penetration distance was found to be at l/L=0.2, where l distance from the tuyere tip and L is the total length (2.44m) of the modelled furnace. The model also predicts that 10% of the injected coal bypasses the tuyere gas stream un-combusted and carried to the free surface, which contributes to ZnO reduction near the free surface.