The Law Of Fugitive Dust Dispersion From Large Open-year Of Stock-pile In Locoregional Area

Large open-yard of stockpile,low cost and large capacity,is popular in the storage of bulk raw materials and industry waste residue,and the adverse environment effect is regarded as a big problem.The research on fugitive dust dispersion law from open-yard of stockpile is of great importance for controlling the pollution of it.In this paper,pertinent literature at home and abroad is collected and analyzed.On the basis of the literature research,study of site test,wind tunnel experiment and numerical simulation on the dust dispersion rule of large open-yard of stockpile is carried out : a large open-yard of stockpile is chosen collecting the bulk material and testing size distribution and density of it;stockpile model is established for the wind tunnel experiment and PIV technology is employed to test the velocity around the stockpile,and velocity field character for different velocities is analyzed;a numerical model is established and validated by the wind tunnel experiment data;the physical property parameters are put into the validate numerical model with discrete phase model to simulate the dust dispersion character for different wind velocities(0.87 m/s,3.91 m/s and 7.22m/s)and partical sizes(10 μm,30 μm and 50 μm).The result shows :(1)The size distribution of the bulk material is mainly focus on 5 μm-200 μm,the median being 70μm and the density of the bulk material is 2844.88 kg/m3.(2)In the wind tunnel experiment,with increasing of wind velocity(0.87 m/s-7.22 m/s),the velocity field structure around the stockpile is stable.(3)In the simulation of fluid-solid phase,when the particle size is 10μm,with the increasing of wind velocity(0.87 m/s-7.22 m/s),the particle dispersion distance becoming further in the down wind direction,the vertical direction dispersion width becoming larger.(4)In the range of 0-1.0 in down wind direction,with the increasing of wind velocity(0.87 m/s-7.22 m/s),the concentration of paticle become lower.In the range of 1.0-2.1 in down wind direction,when the wind velocity is 0.87 m/s,the concentration of paticle become highest,the velocity of 3.91 m/s and 7.22 m/s existing little difference.In the range of 2.1-6.3 in down wind direction,the particle concentrations of all 3 wind velocities is almost equally low.(5)With the increasing of particle diameter,the follwing feature of the particle become worse.At equal initial velocity for particles of 10 μm,30 μm and 50 μm,on the horizontal plane(h=3 mm),with the increasing of particle diameter the dispersion area increases first and then decreases;however,on the horizontal plane(h=3 mm and h=48 mm),with the increasing of particle diameter the dispersion area become larger.(6)With the increasing of particle diameter,the follwing feature of the particle become worse.At equal initial velocity for particles of 10 μm,30 μm and 50 μm,on the vertical plane(z=0 mm),with the increasing of particle diameter the dispersion area become smaller.