Dust removal method for open space of fully mechanized mining face: A cutting area pressure balance method

Abstract

For the problem of serious dust pollution in the workface of integrated mechanized coal mining, this study proposes a new type of local negative pressure sealing dust prevention method. On account of the CFD-DPM approach, mechanisms of the impact of using a new method on dust pollution in diverse situations was studied. This study analyzed the diffusion of diverse sizes of dust. The results show that in the control group, the maximal dust loading in the footwalk void was above 500 mg/m³. During the coal cutting under a downwind or upwind situation, the cross-sectional size of the roadway where airflow passes through and the location of the coal mining wall altered, which resulted in a variation of the entering position and volume of the drum airflow into the footwalk void, thereby affecting the diffusion of dust. After using the new approach, under the downwind condition, the average value of dust load at the elevation of respiratory area in the footwalk void decreased by 93.2 %; under the upwind condition, the dust loading in the footwalk void should be controlled below 50.0 mg/m³. At an intake air speed of 1.5 m/s, the dust loading at the elevation of the pedestrian respiratory area is less than 156.6 mg/m³. The reduction in large particle dust reached 89 %, providing an innovative idea for coal mining operation dust reduction.