采高综采面液压支架喷雾降尘方法改进与应用

摘要

针对大采高综采工作面粉尘污染严重的问题,基于相位多普勒激光干涉仪PDI200MD的雾化特性试验,分别测定6种喷雾降尘常用喷嘴在8 MPa喷雾压力下的宏观雾化特性,以及1.2 m/s扰动风流下的雾滴粒径分布,并根据试验结果设计了文丘里负压喷雾器以及液压支架喷雾降尘方法,最后通过现场粉尘浓度测定考察其应用效果.结果表明:孔径为2.2 mm的含X形导流芯混合式广角实心圆锥形喷嘴的雾化特性最佳,其在8 MPa喷射压力下,雾化角为73.5°,有效射程为5.3m,流量为7.05 L/min;在1.2 m/s扰动风流影响下,特征粒径Do.5、Sauter平均粒径D32以及Herdan平均粒径D43分别为38.541、33.951、41.162 μm,雾滴轴向速度为26.415 ～57.468m/s.液压支架喷雾降尘方法应用后,工作面采样点的总尘及呼尘浓度较传统喷雾降尘方法均出现明显降低,其平均总尘降尘率为86.4％,平均呼尘降尘率为82.5％.%According to a serious dust pollution problem of the high cutting fully-mechanized coal mining face,based on the spraying features experiment of a PDI200MD phase Doppler laser interferometer,macro spraying features of six sparing dust control conventional nozzles with a 8 MPa spraying pressure were individually measured and the distribution of the spaying particle sizes were measured under the disturbance air flow of 1.2 m/s.According to the experiment results,a Venturi negative-pressure sprayer and a new spraying dust control method of the hydraulic powered support were designed and finally the site dust concentration measurements were applied to investigate the application effect.The results showed that the mixed type wide angle solid cone nozzle with X type diversion core and with a pore diameter of 2.2 mm would be best in the spraying features.Under the jet pressure of 8 MPa,the spraying angle would be 73.5°,the effective range would be 5.3 m and the flow would be 7.05 L/min.Under the influences of the 1.2 m/s disturbance air flow,the feature partical size D0.5,Sauter average partical size D32 and Herdan average partical size D43 would be 38.541,33.951 and 41.162 μm individually.The axial velocity of the droplet would be 26.415～ 57.468 m/s.After the application of the new type spraying dust control method to the hydraulic powered support,a total dust and respirable dust concentration at the sampling points of the coal mining face would be obviously reduced than the conventional spraying dust control method,the dust control rate of the total dust was 86.4％ and the dust control rate of the average respirable dust concentration was 82.5％.