粉尘在边界层内的二次悬浮与运移探讨

Study on Second Suspension and Transportation of Dust in Laminar Boundary Layer

针对粉尘经常堵塞除尘管道引起除尘效率降低，能耗增加的情况，对粉尘在湍流主体区和边界层内的受力进行分析，推导出在边界层内粉尘二次悬浮与粒径、风速的关系。边界层内，风速越大，粉尘粒径越大，二次悬浮能力越强。通过试验观察到粉尘在边壁上呈波浪式沉积，且粒径在10-40μm的粉尘沉积量最大。得出在边界层内能二次悬浮的粉尘占总粉尘量的10％时，粉尘不会沉积，且输运风速最低。提出以边界层内粉尘二次悬浮量为10％作为除尘管路风速选择的依据。

In centralized deducting system, the pipelines are often been blocked by dust and it will result in low dusting efficiency and high power cost. The forces on dust in boundary and turbulent region of pipelines have been analyzed, and the relationship between particle size and ventilation rate of suspensions has been derived. The larger of wind speed, and the larger of dust size, the second suspend of dust in the Laminar Boundary Layer is easier. Then experiments discovery that the dust deposited on the wall are like waves, and the particle of whose size between 10 μm and 40 μm can deposit on the wall easily. The number of particles whose size are larger suspension size is more than 10%, the dust will not deposit in pipes has been found.