大高差溜槽粉尘颗粒扩散运动规律数值模拟

为解决大型露天矿回填溜槽运输系统产生的粉尘污染问题,运用溜槽物料牵引流、落料诱导气流和剪切气流理论分析了溜槽工艺的粉尘析出机理。研究发现,溜槽运输系统粉尘的析出是诱导空气的尘化作用、剪切压缩尘化作用的结果,粉尘析出的主要影响因素包括物料的基本属性、运行速度及溜槽出口落差。基于气固两相流理论,利用数值模拟方法计算小空间粉尘颗粒的扩散规律和颗粒运动轨迹,结果显示溜槽系统粉尘粒径范围在0~100 μm,物料流速度大于10 m/s时,粉尘大部分被扬起,溜槽出口距离平台距离越大粉尘析出量越大。为制定多尺度、综合的粉尘防治措施提供必要的理论支撑与科学依据。

Numerical simulation of dust particle diffusion elevation movement during a process of large height difference chut

Material-chute-traction current, blanking-induced flow, and shear-flow theory were employed to investigate the mechanism of dust precipitation during chute-transportation. The goal was to solve dust-pollution problems of the chute-transportation system in a large open-pit mine. The study revealed that the effect of shear compression and integration were the results of chute-transport-system dust precipitation. Dust precipitation factors included the basic properties of the materials, their speed, and the drop-chute outlet. Based on phase-flow theory, numerical simulation was used to calculate the diffusion regularity of dust particles and particle trajectories in space. The results show that the dust-chute system particle-size range is <1 to 100 μm, and that most of the dust is raised when the material flow-rate is greater than 10 m/s. The greater the distance from the exit chute to the platform, the greater is the amount of dust precipitation. This study provides a scientific basis and theoretical support for formulating multi-scale, integrated dust control measures.