Study On Dust Control Technology Of Spray Combined Negative Pressure Entrainment In Fully Mechanized Face Of Sandaogou Coal Mine

In view of the serious dust pollution of the fully mechanized coal mining face,the current dust control technology can not effectively control the dust pollution.In this thesis,theoretical analysis,field measurement,numerical simulation and experimental testing are combined to carry out the research on the dust control technology of spray combined with negative pressure entrainment in fully mechanized coal mining face,which is of great significance to the dust control in fully mechanized coal mining face.Taking the 45205 fully mechanized working face of Sandaogou Coal Mine as the research object,the dust concentration,dispersion and free silicon dioxide content of the fully mechanized mining face were measured at the sampling points selected at the fully mechanized working face through field measurement,and the dust concentration distribution characteristics and dust particle size distribution characteristics of the fully mechanized working face were obtained.The CFD-DEM method is used to establish the air flow dust numerical model of the fully mechanized working face,obtain the air flow movement characteristics of the fully mechanized working face,master the dust particle diffusion law of the drum coal cutting and frame shifting processes,and obtain the dust diffusion law of different particle sizes in the fully mechanized working face.The air flow characteristics of the negative pressure entrainment device were studied by COMSOL numerical simulation software,and the effects of inlet velocity and number of device outlets on the induced air flow performance were analyzed.The results show that the inlet velocity is directly proportional to the induction performance of the suction device.With the increase of the number of outlets,the induction performance of the negative pressure entrainment device first increases.When the number of outlets reaches 18,the adsorption of the negative pressure entrainment device tends to be saturated,and then the number of outlets is no longer a factor affecting the performance of the negative pressure entrainment device.In addition,COMSOL simulation software is used to compare and analyze the atomization effect of dust removal schemes,and then the appropriate dust reduction scheme is selected.The atomization characteristics and wind resistance of the nozzle are tested on the selfdeveloped experimental platform.According to the experimental results,the nozzle with good droplet crushing effect and strong wind resistance is selected for use on the hydraulic support.The experimental results of atomization characteristics show that the droplet size of supersonic nozzle is always smaller than that of the other two nozzles at the same pressure and distance.The wind resistance test results show that the spray wind resistance of the pressure fan nozzle is less than the spray wind resistance of the ultrasonic nozzle and less than the spray wind resistance of the supersonic nozzle.Therefore,the supersonic nozzle is selected for the inter rack wet dust removal scheme.Based on the above research results,a project case study was conducted,and the dust reduction efficiency reached more than 88%.This thesis has 46 figures,12 tables and 99 references.