| A large amount of dust will be generated during coal mining in the fully mechanized excavation face,which not only seriously threatens the occupational safety and health of underground workers,but also affects the development of enterprise production and social stability.Due to the characteristics of multiple mechanical equipment,complicated procedures,large ventilation air volume,and narrow space in the fully mechanized excavation face,the amount of dust generated in the comprehensive excavation roadway is large and concentrated.At present,most coal mines fail to implement real-time and effective dust prevention and reduction in accordance with the operation requirements of the roadheader working at heading face.Based on the systematic study of dust removal technology and methods for fully mechanized excavation face at home and abroad,this paper combines the actual conditions of comprehensive excavation roadway and adopts a combination of theoretical analysis,numerical simulation,experimental testing and underground industrial test application to design a method The high-efficiency atomization mechanical dust removal system of the comprehensive excavation roadway provides a new idea for the prevention and control of dust in the comprehensive excavation roadway.The main results are as follows:(1)Based on the air-solid two-phase flow theory,the CFD-DPM model was used to establish a three-dimensional mathematical model of the dust diffusion of fully mechanized excavation work,and the finite element analysis method was used to analyze the dust migration trajectory and the dust deposition of different particle sizes in the comprehensive excavation roadway.The speed is simulated.According to the dust distribution characteristics and migration routes of the fully mechanized face,a new mechanical dust removal,purification and dust reduction system consisting of a dust extraction fan,a self-oscillating nozzle,a fan,a water drop separator,and a water storage tank was developed and designed.(2)The two-dimensional model of the atomizing nozzle of the inclined wall micro-oscillation cavity was established by using Auto CAD,and the optimal operating parameters of the single nozzle and the combined nozzle were determined through the simulation analysis of the single nozzle and the combined nozzle.Through optimization experiments on the three factors of nozzle diameter,expansion angle and throat distance,with the goal of optimal spray performance,the main technical parameters of its key atomization element-self-oscillation nozzle were determined.(3)In a fully mechanized excavation face work of a mine,an industrial test was carried out on the mechanical dust removal,purification and dust reduction system of this paper.The results showed that:after adopting the research results of this paper,the dust concentration in the test part of the manned working area of the comprehensive excavation face has been reduced to100 mg/m~3 below,it meeted the coal mine safety production standards;the dust removal efficiency of the mechanical dust removal purification dust reduction system reached 98%,which was more than 20%higher than the traditional spray dust removal technology. |
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