高溜井卸矿过程中产生的冲击气流是卸矿硐室及其附近巷道产尘的主要原因,通过分析冲击气流产生的基本方程,根据相似原理,导出了高溜井卸矿冲击气流的相似准则数,以李楼铁矿24#卸矿溜井为原型,建立了高溜井的相似模型,并对不同卸矿条件下的冲击气流进行了实验研究.结果表明:冲击风速随卸矿流量的增加而增加,但其增幅随卸矿流量增加而减小,最大冲击风速与卸矿流量成近似幂函数关系,且卸矿高度越大,幂指数越大,实验得幂指数范围为0.593 ～0.732;卸矿高度越高冲击气流越大,且随着卸矿高度的增加,矿石颗粒分散的空间越大,颗粒间相互作用越小,对溜井内气流的诱导作用越大,冲击气流增加的幅度随卸矿高度的增加不断提高;矿石粒径范围及出口阻力系数越大冲击气流越小;同时卸矿的中段越多,冲击气流会产生叠加而增大,但远小于各中段单独卸矿产生冲击气流的总和.%Impacting air flow producedin ore drawing througha high ore pass is the main reason why ore dumping chamber and adjacent tunnel produce dust.Here,according to the similarity principle,the similarity criteriaof impacting air flow produced during unloading ore in a high ore pass were derived by analyzing the basic equation.Taking 24# ore pass in Li Lou iron mine as the original model,the similarity model of the high ore pass was built,tests were conducted for impacting air flows under different unloading ore conditions.The results showed that the impact wind speed increases but its amplitude growth rate decreases with increase in the unloading ore flow rate,the maximum impact wind speed and the unloading ore flow rate form approximately a power function relation,the higher the unloading ore height,the larger the power exponent,the range of power exponent measured with tests is 0.593-0.732;the higher the unloading ore height,then the bigger the impacting air flow,the larger the space for ore particles dispersion,the smaller the interaction between particles,the bigger the induction effect on the air flow in the ore pass;the growth rate of the impacting air flow increase with increase in the unloading ore height;the greater the ore particle size range and drag coefficient at the exit,the smaller the impacting air flow;impacting air flow increases due to superposition effect with increases in segments of unloading ore,but it is far less than the sum ofimpacting air flows generated due to the separate unloading ore in each segment.
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