Turbulence and velocity distribution profile of swirling jets and their influence on the furnace bath

Observations of the Ausmelt furnace operation during the processing of various sulphide materials under the conditions of the production programme, as well as theoretical substantiations based on the developed mathematical models allowed to assess the influence of effective swirl on the turbulence and pulsation of the TSL blast jet. Assessment of the blast pulsations caused by the design features of the lance, physical and chemical properties of the melt, process temperature and the occurrence of vibration combus-tion from natural gas combustion made it possible (all other conditions being equal) to predict and control the depth of the lance immersion into the melt, and to estimate the effective swirl and its change during the melting process. According to the calculations performed, the pulsation frequency decreases with increa-sing immersion depth of the lance and increases with decreasing immersion depth into the melt. At a con-stant immersion depth of the lance, with increasing air mixture outflow velocity (degree of effective swirl), the frequency of oscillations (pulsations) of the blast increases. These features of swirling jets allow con-trolling the lance by the recorded sound parameters coming from the furnace, both by instrumental control methods and “by ear” of the furnace operator. Turbulization of swirling flows of blast jets prevents the for-mation of stagnant zones in the furnace bath, improving mass transfer and equipment productivity due to melt rotation. Studies on additional increase of turbulization by twisting the co-current flow jets in opposite directions on the operating Ausmelt industrial furnace did not reveal any visible positive effect on melting. Analyzing the works and research of other authors in this area and the comparison thereof showed complete comparability of the results and conclusions between laboratory tests, theoretical generalizations and indus-trial tests.