Abstract: In order to reduce the dust concentration at the continuous mining face,the effect of adding the vertical downward deflection angle of the extraction and pressure air openings on the dust reduction effect was studied. Taking the 25211 working face of Hongliulin Coal Mine as an example,six parameters,including the diameter of the pressure air cylinder d1,the horizontal deflection angle of the pressure air outlet α1,the vertical downward deflection angle of the pressure air outlet β1,the diameter of the extraction air cylinder d2,the horizontal deflection angle of the extraction air outlet α2and the vertical downward deflection angle of the extraction air outlet β2,were taken as the air flow control parameters,and the dust concentration data after different air flow control parameters were obtained through numerical simulation. Based on the response surface method and particle swarm optimization algorithm,the optimal air flow parameters of the continuous mining face were obtained with the dust concentration at the driver′s position and the height of the breathing zone as the optimization targets. The study results show that the dust concentration decreases by adding the vertical downward deflection angle of the extraction and pressure ducts, changing the pressure and extraction ratio and the position of the pressure ducts from the dust source. The dust concentration at the lower part of the tunnel is higher than that in the upper part of the tunnel in the working space between the continuous mining face and the continuous mining machine. The dust concentration shows a change trend of gradually increasing and then decreasing within 40 m from the headway. The influence of each parameter on the dust concentration at the driver′s position and the height of the breathing zone are as follows:the degree of influence of each parameter on the dust concentration at the driver′s position and the height of the breathing zone is α1 > β1 > d1 > d2 > α2 > β2, d2 > α1 > d1 > β1 > β2 > α2respectively. Based on the above analysis,the best air flow parameter of the continuous mining face is d1 = 0. 9 m, d2 = 1. 1 m, α1 = 0°, β1 = 1°, α2 = 10°, β2 = 8°. The dust concentration at the driver′s position is reduced from 297. 09 mg / m3 to 134. 98 mg / m3 after the control,a reduction of 54. 57%;The dust concentration at the height of the breathing zone is reduced from 217. 35 mg / m3 to 86. 50
mg / m3,a reduction of 60. 20%. The dust concentration in the roadway is effectively reduced and the goal of efficient dust prevention and control at the continuous mining face is achieved.

Key words: mine dust prevention and control,continuous mining face,long pressure short pumping,air flow control,response surface method,particle swarm optimization algorithm