Effect of wind curtain on dust extraction in rock tunnel working face: CFD and field measurement analysis

Dust pollution in fully mechanized working faces of rock tunnels seriously threatens the safe operation and workers' health. In order to effectively control the dust and improve the working environment in the working face, we simulated the effect of dust suction position, d(s )and the exhaust air rate, Q(s) on dust diffusion at the working face by the CFD method. The accuracy and reliability of the numerical simulation were verified by field measurements. It was shown that when d(s) was 0, 1/4, 1/2, and 3/4, the overall airflow in the tunnel was in a disordered state. The dust, carried by the airflow, was eventually spread to the whole tunnel. When (s )was 1, an effective dust control wind curtain with the airflow direction pointing to the working face was achieved under the joint action of exhaust air and pressing air. A uniform flow covering the full section of the tunnel was formed within the range of 4.2-6.5m from the working face. The dust was controlled in an enclosed space between the road-header and the working face. When Q(s )was 330-500 m(3)/min, an effective dust control wind curtain was always formed in front of the roadheader. Consequently, the recommended air exhaust rate under the minimum energy consumption was 330 m(3)/min. (C) 2020 Elsevier Ltd. All rights reserved.