Study On The Diffusion Law Of Dust Pollution Under Macroscopic And Microscopic Views And Dust Control Technology In Fully Mechanized Mining Face

With the development of science and technology as well as the improvement of mechanization,fully mechanized coal mining methods have been widely used in coal mines.The increase in coal production has led to a sharp increase in dust concentration in production sites.At the same time,there are many working equipments in the fully mechanized mining face,which cause more disturbance to the flow of the wind flow,the state of the wind flow field is unstable,and the flow of the wind flow is complex and variable,which makes it difficult to predict the pollution diffusion law of high concentration dust.The unclear law makes it difficult to target for selecting reasonable and efficient dust reduction measures,the dust reduction effect is not good,high concentration dust seriously pollutes the environment,threatens the safe production of coal mines and the physical and mental health of miners.Therefore,mastering the precise diffusion law of dust pollution in fully mechanized mining face,and then researching and designing high-efficiency dust control technology has important theoretical and social significance for guiding coal mine dust control,equipment research and development and occupational disease protection.This paper applies theoretical analysis,numerical simulation and field measurement data to combine the technical methods,from the macroscopic and mesoscopic perspectives to study the diffusion law of dust pollution in fully mechanized mining work.Through single operation and multi-process joint operation of dust simulation determined the distribution of dust more accurately.The dust control technology was studied by the principle of ventilation and dust control,and it was applied on site.The main research contents are as follows:A mathematical model of wind-dust diffusion movement in fully mechanized mining face was established.The SolidWorks modeling software was used to establish a proportional fine physical model that can accurately reflect the actual situation of the fully mechanized mining face.The ANSYS ICEM meshing software was used to set specific grid parameters for different equipment of fully mechanized mining face,and uses local mesh refinement technology to achieve accurate solution of fully mechanized mining face.The ANSYS FLUENT software was used to simulate the behavior of wind-dust diffusion movement in fully mechanized mining face.The state of wind flow field in fully mechanized mining face under actual wind speed was studied,and the law of wind speed decreasing first and then increasing in coal face was determined.By simulating single dust source dust generation and dust source to produce dust together,the wind flow stream and dust diffusion trace are used to reveal the distribution of dust concentration in fully mechanized mining work.Combined with on-site measurement,it is clear that the area of advancing support is the highest dust concentration area and the diffusion behavior of dust is more complicated,and the diffusion state of the dust particles on the time scale is studied by using the visualization technology of the simulation software.The variation of the parameters of the spatial position,diffusion and sedimentation of the dust particles under different time conditions is obtained.From a microscopic point of view,the law of dust pollution diffusion in fully mechanized mining is supplemented.According to the result of dust pollution diffusion law,the shearer driver's range of activities has the highest dust concentration.In order to reduce the dust-proof dust control cost of coal enterprises,the dust control technology is more targeted and purposeful.Based on the principle of ventilation and dust control,the dust control technology of dust-isolating air curtain is studied,and designed and developed a pull-out type of dust fan.The wind flow forms air curtain behind the fan air outlet,and the low concentration zone is isolated from the high concentration dust zone through the air curtain,and the device is applied on the spot.The dust concentration at the driver of the shearer is greatly reduced,and the average dust removal rate reaches 90%.The overall dust concentration of the working face is reduced to some extent,and the average dust removal rate is 47.8%.The working environment has been improved.