Research On Dust Suppression Technology And Optimization Of Air Cell In Fully Mechanized Excavation Face

At present,China’s coal mines mainly use high-pressure spraying,dust fans,long pressure and short extraction ventilation and other measures for dust prevention and control work,which has achieved certain results,but due to the limitations of each dust reduction measures,economic and other reasons,some of the comprehensive excavation work face still has the problem of dust concentration over the limit.The paper aims to play an important role in improving the working environment of the coal mining face by designing the air chamber dust reduction technology for the heaving face,which is an important guideline for dust prevention and control work at the heaving face.The paper takes the No.2 coal No.2 return air tunnel heaving workface of Balasu coal mine as the research object,constructs a mathematical model of dust movement,combines the wind curtain jet theory and the advantages and disadvantages of existing dust reduction measures,proposes and designs the air chamber dust reduction technology for the heaving workface,and optimises the equipment arrangement parameters through numerical simulation and field experiments in order to improve its dust reduction efficiency.By comparing the simulation results of air flow field of long pressure and short extraction ventilation,single air curtain dust control and air chamber dust reduction technology,it was determined that the air chamber dust reduction technology is feasible and effective in actual production application.The results show that there is a critical value for the location of the outlet of the positive pressure duct,which is too far from the header face and will increase the possibility of secondary dust emission in the roadway,and too close to the header face will destroy the effect of the air chamber closure,and the outlet of the positive pressure duct is 15 m away from the header face with the best dust reduction effect.The dust reduction efficiency of the air chamber technology will not be improved if the air curtain is positioned in the closed area of the air chamber,and the dust reduction efficiency of the air chamber technology will not be improved.On the premise of not changing the suction volume of the negative pressure duct,the smaller the diameter of the end of the negative pressure duct,the better the effect of the air chamber dust reduction technology.When the diameter of the end of the negative pressure duct is changed from 0.8 m to 0.6 m,the dust reduction efficiency within the closed area of the air chamber increases by 45.4%,and the dust reduction efficiency outside the closed area of the air chamber increases by 3.7%.