综放工作面多尘源粉尘扩散规律的相似实验

为了掌握综放工作面多尘源粉尘扩散分布规律，运用相似理论和气固两相流方程，导出了综放工作面相似准则数，设计出相似实验模型，模拟风速为1.0，1.5，2.0，2.5 m/s，含水率为1.69%，2.63%，3.83%，4.87%下割煤、移架、放煤、转载以及多工序作业粉尘扩散。研究表明：风速对各尘源的影响较大，但影响结果不同，实际最佳控尘风速为1.5 m/s；煤尘含水率对粉尘扩散影响比较显著，最佳含水率不宜低于3.8%；多尘源粉尘浓度分布叠加效应十分明显，在实际防尘中需要采取单点防降尘和多点防降尘相结合的措施。

Similarity experiment on multi-source dust diffusion law in fully mechanized caving face

In order to understand the regularities of multi-source dust diffusion and distribution in a fully mechanized caving face，similar numbers were derived on the basis of similarity rule and kinematic equation of gas-solid two-phase flow.In addition，a scaled test model was constructed to simulate dust diffusion during coal cutting，support advancing，coal caving，transshipping and other multi-operations under the conditions of 1.0，1.5，2.0，2.5 m/s wind velocity and 1.69%，2.63%，3.83%，4.87% moisture content.Results indicate that the wind velocity has a great impact on each dust source while the outcome of the impact varies according to different situations.The optimal wind velocity is 1.5 m/s.Moreover the moisture content of coal dust significantly affects dust diffusion，and the optimal moisture content should not be less than 3.8%.From these results，it is concluded that the superimposed effect of the multi-source dust concentration distribution is obvious，therefore the comprehensive measures of dust prevention and reduction should be taken in practice.