CFD Simulation of the Effects of Mushroom Heads in a Bottom-Blown Copper Smelting Furnace

The mushroom head generated in the oxygen-enriched bottom-blown copper smelting furnace plays a critical role to prevent the erosion of oxygen injectors and prolong the life of furnace lining with effective temperature control. A numerical simulation was performed to investigate the effect of the growth direction of mushroom head on the flow field and smelting in this study. The VOF multiphase flow model coupled with the standard k-epsilon turbulence model was adopted to study the effect of radially and axially inclined mushroom heads on the flow distribution and the splash rate. The results show that the formation of mushroom head can enhance the stirring intensity by enlarging the average melt velocity. Changes in the growth directions of injector mushroom heads more toward the vertical direction decrease the mixing uniformity with a large velocity gradient and aggravate more splashing, while changes toward the horizontal direction improve the stirring uniformity. As an example, when the growth directions of the mushroom heads were changed by 10 deg toward the vertical direction, the average melt velocity increased from 0.428 to 0.728 m/s and the RSD (relative standard deviation of melt velocity) decreased from 134 to 121 pct. On the other hand, changes in the growth directions of mushroom heads in the pair of injectors toward each other increase the extent of the gas jet coalescence and decrease the mixing uniformity, while the changes away from each other reduce the gas jet coalescence and the splash rate. The splash rate of latter decreased by a factor of 2.7 when the angles of the mushroom growth away from each other were each by 10 deg from parallel compared with the changes toward each other by the same angle.