Negative Pressure Dust Reduction Technology and Dust Diffusion Characteristics of the Fully Mechanized Coal Mining Face
摘要
In order to solve the problem of dust escaping from the fully mechanized coal mining face, a new type of negative-pressure device based on the Coandă effect for shearers was designed. Computational fluid dynamics (CFD) was used to study the influence of different structural parameters on the suction effect of the device and the spatiotemporal evolution of dust in the roadway. The results indicate that, as the slit width, curvature radius, and inlet angle of inclination increase, the suction airflow first increases and then decreases. The suction air volume stops changing when the radius of the center increases to 195 mm. The orthogonal test concluded that the radius of the center had a significant effect on the suction volume. The optimal combination of parameters is a 220 mm radius of the center, 1 mm slit width, 25 mm curvature radius, and 15° inlet angle, and the suction air volume can reach 496.92 m3/min. A comprehensive analysis of the spatial dust concentration and particle size distribution, before and after the application of the negative pressure device, shows the following results. After the device is applied, high-concentration dust primarily accumulates near the rocker arm and drum. Meanwhile, dust accumulation above the shearer body is significantly reduced. Near the height of the breathing zone, the negative pressure device’s suction effect dilutes the dust concentration and effectively reduces the dust load. In addition, the dust of various particle sizes in the work area is significantly reduced, leading to a notable improvement in the working environment for the workers.