| The oxygen bottom blowing smelting method is a molten pool smelting technology independently researched and developed in my country.It has a series of advantages such as low investment,short process flow,strong adaptability of raw materials and low energy consumption.However,in the actual production process,there is an oxygen lance exhaust.Unreasonable cloth,low mixing efficiency,violent splashing and other problems.For this reason,this thesis uses a combination of numerical simulation and water model experiment to systematically study the number of nozzles,arrangement scheme,blowing gas flow rate,bath depth,etc.on the flow behavior of two-phase flow in the oxygen bottom blowing smelting furnace,and splash The influence law of height and mixing efficiency,and the corresponding optimization plan for the structure and technical parameters of the bottom-blowing furnace reactor is proposed.The main research contents and results of this thesis are as follows:1.Based on the principle of similarity,a water model with a similarity ratio of1:9.3 was established to describe the bubble flow and mixing behavior of the bottom-blown smelting furnace process.Under the 9-nozzle mode,the nozzle type and arrangement scheme and the gas flow were compared to the mixing influence of time and provides a basis for numerical simulation verification.The study found that:(1)In the single-row arrangement,the mixing time gradually decreases as the depth of the molten pool increases,especially when the depth of the molten pool exceeds 190mm,the mixing time decreases sharply,dropping from 161 s to 101 s.(2)In the single-row arrangement scheme,as the nozzle diameter increases,the mixing time gradually increases,from 84 s to 101 s.(3)With the increase of the nozzle inclination angle,the mixing time dropped from 179 s to 84 s,and as the nozzle inclination angle continued to increase,the mixing time increased to 90 s instead.(4)As the amount of air injection increases,the mixing time first decreases and then rises,which proves that the amount of air injection is not as large as possible.(5)In the double-row arrangement plan,the farther the nozzle blowing gas is from the center of the bottom blowing furnace,the more obvious the increase in mixing time is.When the inclination angle of one row is 14°,the shortest mixing time is 74 s.2.This thesis uses the Eulerian-Eulerian model to describe the gas-liquid two-phase flow behavior in the bottom-blown copper matte converting furnace.Under different injection gas flow rates,the influence of the gas-liquid two-phase behavior,injection height,gas content and mixing time in the molten pool,the results are as follows:(1)Under the original 9-nozzle mode in the industry,With the increase of the nozzle inclination angle,the spray height of the molten pool liquid surface dropped from 0.65 m to 0.5 m,and the spray situation was weakened accordingly.At the same time,the total volume of gas in the molten pool has also increased accordingly.The total volume of gas in the molten pool has increased from 5.7 m~3to 7.6 m~3,and the mixing time has been shortened accordingly,from 185 s to 121 s,indicating that the nozzle angle is increased and this can achieve the effect of enhancing the stirring of the molten pool.(2)After the number of nozzles is doubled to 18 nozzles,the highest total gas volume appears in the dual-row 0°and 14°arrangement modes,the total gas volume is 11.9 m~3,the mixing time is 277 s,and the lowest value of spray height appears in the double row-14°and 14°arrangement mode,the spray height is0.39 m,the mixing time is 237 s,and the total volume of gas inside the molten pool is9.2 m~3.(3)With the increase of the blowing gas flow,the mixing time under different arrangement modes shows a shortening trend,and the total volume of gas inside the molten pool increases accordingly.However,considering comprehensive considerations,the best solution in this thesis is:18 nozzles,double rows and 14°symmetrical arrangement,air injection volume of 3300 m~3/h,and molten pool height of 1.488m. |
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