Numerical Simulation Of Nonlinear Enhanced Stirring In Non-submerged Top Blowin

Gas stirring is widely used in the metallurgical industry,especially in the copper pyrometallurgical process,and is applied in the main production processes such as melting,converting and refining.In the copper blowing process,the traditional gas stirring flow has a large low velocity region and the slag layer is not driven by enough force.Therefore,it is necessary to optimize the blowing process in the copper blowing process,improve the momentum transfer ability between the gas slag phases and enhance the turbulence intensity of the slag layer fluid without affecting the copper content of the slag layer.In this document,two nonlinear enhanced mixing schemes are proposed,and the period and amplitude of the nonlinear gas velocity control waveform are numerically analyzed,and the optimal lance arrangement scheme and furnace type a re matched to obtain the slag layer flow characteristics for each working condition to realize the process enhancement of copper blowing.In this paper,a mathematical model of top-blowing furnace is established,and the reliability of numerical simulation is verified by the water model validation platform.By analyzing the flow field characteristics such as velocity distribution,turbulent kinetic energy distribution,flow field streamline,and gas phase distribution,the enhanced mixing characteristics of nonlinear blowing are elucidated,and the effects of lance arrangement method and furnace type on gas-slag two-phase mixing are discussed.The results show that the pulsed velocity input can break the steady blowing type of constant velocity blowing at the same inlet flow rate.Compared with the constant velocity blowing system,the velocity of sine-wave blowing system and rectangularwave blowing system increased by 24.03% and 13.96% respectively,the turbulent kinetic energy and turbulent kinetic energy dissipation rate of sine-wave blowing system increased by 7.46% and 12.59% respectively,the variable velocity smooth sine-wave blowing system improves the flow of the slag layer.The results of the study show that the pulsed velocity input can break the stable blowing of fixed-rate blowing at the same inlet flow rate.Compared with the fixed-speed blowing system,the sine wave blowing system and rectangular wave blowing system speed increased by 24.03% and 13.96%,respectively;the turbulent kinetic ener gy and turbulent kinetic energy dissipation rate of the sine wave blowing system increased by7.46% and 12.59%,respectively,and the sine wave blowing system with smoother variable speed can improve the fluidity of the slag layer.The two types of lance arrangement,double-row lance arrangement between the two rows of lances below the flow field there is energy dissipation;single-row lance arrangement can increase the contact area of oxygen-rich air and slag phase,single-row lance arrangement of the average velocity of the slag layer increased by 117.93%,the proportion of the flow of low velocity region reduced by 27.72%.In the two furnace type matching schemes,the oval furnace body compared to the circular furnace body slag phase velocity decreased by 26.09%,but its turbulent kinetic energy increased by 7.53%,and the average velocity of the blister copper phase in the Z-axis direction is lower than 0.005m/s,which is conducive to suppressing the increase of copper content in the slag phase.In summary,a sine-wave blowing system with a variable velocity period of 1 s and an amplitude of 15 m/s,a single-row lance arrangement and an oval furnace body are selected to significantly improve the flow characteristics in the furnace.The coupling mechanism of optimal nonlinear enhanced stirring,lance arrangement method and furnace type are elucidated.