富氧底吹熔炼炉内气液两相流动的数值模拟

摘要

以某公司的富氧底吹熔池熔炼炉为原型,运用数值模拟的方法对炉内氧气-铜锍两相流动进行三维瞬态模拟,研究炉内气泡主要参数、气含率分布规律、氧枪出口附近压力变化以及液面波动情况.并借助于高速摄像仪设备,对水模型实验中气泡形成、合并、变形及破碎过程进行研究,所得结果与模拟结果进行比较.结果表明:所建立的数学模型是合理的.氧气铜锍两相流动模拟结果表明,炉内气泡形成时间为0.12,～0.25 s,生成频率为4～5 Hz,其短轴大小集中在3.5d~6.5d(d为氧枪直径尺寸):气泡停留时间为0.2～0.4 s,其在熔池内的平均上浮速度约为4 m/s；7°和22°氧枪出口气泡后座现象出现的平均频率分别为5Hz和7Hz,作用时间为0.06 s；高效反应区存在于熔池上部区域；气相搅动液相所形成的表面重力波在沉淀区传播的过程中,波幅衰减很快,当波传播到出渣口附近时,液面趋于静止.%The oxygen-copper matte flow, which covers bubble parameters, gas holdup distribution, inlet pressure variations and the fluid level fluctuation, was investigated by three-dimensional transient simulation in a bottom-blown bath smelting furnace, prototype of which is oxygen enriched bottom-blown furnace from some company. The formation, coalescence, deformation and breakage of bubble were captured using a high speed camera system in a water model, and the overall features of the bubble dynamic simulation were compared well with our experimental observations, as verified the accuracy and availability of this model. The results show that the continuous bubble formation time is 0.12-0.25 s and the bubble formation frequency is 4-5 Hz, the average rising velocity for the bubble is 4 m/s, and the bubble residence time ranges from 0.2 to 0.4 s. The sizes of bubbles forming in melt are about 3.5-6.5 times as that of the size of lance. The average frequency of phenomena of bubble back-attack occurs at 7?and 22? the lance outlet is 5 Hz and 7 Hz, respectively, and the work time is 0.06 s. The gas phase mainly centers on the upper of the bath, so it is likely that high efficiency reaction core model is on upper of the copper matte. The amplitude which is very small at the slag hole nearby decays rapidly on side of settling zone as a result of the viscous dissipation caused by the high viscosity of smelt.