The impacts of the axial-to-radial airflow quantity ratio and suction distance on air curtain dust control in a fully mechanized coal face

To understand the impacts of the axial-to-radial airflow quantity ratio (denoted as R) and the suction distance (denoted as Ds) on air curtain dust control in a fully mechanized coal face, the 3down610 coal face in Jiangzhuang coal mine was numerically simulated in this study. A mathematic model was established to describe the airflow migration and dust diffusion in a coal face, and a scaled physical model was constructed. The comparison between simulation results and field measurements validated the model and the parameter settings. Furthermore, the airflow migration and dust diffusion at various R and Ds are analyzed using Ansys CFD. The results show that a reduction of R and Ds is conducive to the formation of an effective axial dust control air curtain; the dust diffusion distance decreases with the decrease of both R and Ds. By analyzing the simulation results, the optimal parameter for air curtain dust control in the 3down610 coal face and those faces with similar production conditions is determined as R = 1/9 and Ds = 2 m. Under the optimal parameter condition, the high-concentration dust can be confined in front of the mining driver within a space 5.8 m away from the coal face.