大倾角综放工作面粉尘运移速度变化规律及影响因素分析

Analysis on Variation Law and Influencing Factors of Dust Migration Velocity in High Inclination-angle Full-mechanized Top-coal Caving Face

大倾角综放工作面内的粉尘运移过程主要受重力和拖曳力的作用。通过对其进行受力分析，分别建立了沿工作面方向和垂直工作面方向上的粉尘运动速度模型，研究其变化规律。结果表明：在拖曳力和重力作用下，风速、工作面倾角、粒径是影响粉尘运动速度的主要因素；沿工作面方向上，在0～0．2s内，粉尘运动速度快速增加至接近于风速，且倾角和风速越小，逼近趋势越明显；沿垂直工作面方向，粉尘粒径越大、倾角越小，最终稳定沉降速度越快，5μm粒径的粉尘颗粒在工作面45°倾角条件下的沉降速度为0．36m／s，与实际相符。研究结果为更好地采取措施降低采煤工作面粉尘浓度提供了理论支持。

The dust mainly subjects to gravity and fluid drag force during migration in the full-mechanized top-coal caving face of high inclination-angle. The dust velocity models of alonging and vertical to working Face are established, studing the variation law through stress analysis. The results show that the dust velocity is mainly affected by wind speed, inclination-angle of working face and particle size under the action of fluid drag force and gravity. In direction alonging working face, the dust velocity increases rapidly near to wind speed during 0 - 0. 2 s,The smaller the inclination-angle and wind speed are, the more obvious the dust velocity approaching to the wind speed. In direction vertical to working face, the larger the dust particle size, the smaller the dip angle, and the faster the final settling velocity, and the final settling velocity is 0. 36 m/s for dust of 5 μm diameter at the condition of 45 ° inclination-angle, which is consistent with the actual situation. The result pro- vides a theoretical support to take better measures to reduce dust concentration in coal mining face.