| In recent years,coal resources are still the main body of China's energy consumption.The coal industry not only provides the possibility of rapid and efficient development for various industries,but also plays a supporting role in China's social development and economic construction.Dust has long been an unavoidable problem in coal production.In the process of coal production,a large amount of dust will be produced,which seriously endangers the safety of the staff and the service life of the production equipment.For composite factors based on the technology of laser doppler interference dust coupling experimental study,the comprehensive mechanized mining face dust hazard management,protection of underground work personnel's physical health have a vital role.Therefore,this paper studies the relationship between particle size velocity concentration and dust removal efficiency of nozzle fog field by combining theoretical analysis with experimental research.Theoretical research and analysis of the nozzle jet atomization mechanism,design and build the atomization characteristics of phase doppler interferometer experiment platform,established the nozzle atomizing effect index of research,design and laser doppler atomization characteristic experiment,through the macroscopic property experiment it is concluded that the effective range,maximum range atomization Angle of fog field and the relationship between the hydraulic pressure,air pressure;Through microscopic characteristics experiment droplets size along the direction of the axis of the spray field,along with the rising of the measuring point and the distance between the nozzle,on the radial,droplet diameter measuring point on the different cross section of radial decreases continuously with the increase of the distance between the nozzle,and with the increasing of water pressure and air pressure,particle diameter is decreased;Under the same conditions,the axial velocity of the droplet is much larger than that of the radial velocity,and the axial velocity of the droplet is dominant.When the water pressure is constant,the velocity of the droplets increases with the increase of air pressure first and then decreases.In the direction of the axis,the farther from the nozzle,the smaller the droplet density in the fog field,the larger the counting density,the farther from the axis in the radial direction,the smaller the concentration of droplets and the larger the counting density;Design and laser doppler dust coupling simulation experiment,through the analysis and research of fog field particle velocity and concentration field under the condition of different rate of dust,the dust efficiency is obtained good point for the nozzle before 1.5 m of the measuring point,far from the axis of the dust efficiency is slightly higher than the distance of measuring points of axis and the axis of the measured points near the station.When the water pressure is constant,the higher the pressure,the higher the dust and dust removal rate;When the pressure is constant,the higher the water pressure,the higher the dust and dust removal efficiency.For gas water atomization nozzle,dust efficiency of the best combination of water pressure to the water pressure of 0.6MPa,pressure is 0.5MPa,best dust point(3,0.6)and(3,-0.6),the optimal dust interval is 2800 mm to 3200 mm,best drop dust field particle size in the range of 45?48?m,best dust reduction speed in the range of 14.5m/s?15m/s,the best concentration of cloud droplets falling dust field range is 2200g/m3?2400g/m3,best drop counting the density of dust field range is 60000/cm3?62000/cm3;After coupling between the fog field and the dust field,the particle size of the droplets increases,the velocity decreases,and the concentration increases. |
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