Study on Semi-enclosed Area Joint Dust Control Technology of Comprehensive Excavation Face
To effectively improve the dust reduction efficiency of comprehensive excavation face and overcome the limita-tions of a single dust reduction mode,a simulation model of comprehensive excavation face is established,and the reliability of the simulation results is verified by field measurement results.The wind flow field and dust diffusion and migration law of com-prehensive excavation roadway are studied,and the characteristics and distribution range of high-concentration dust accumula-tion are obtained.The results show that the main dust generation source is at the head of comprehensive excavation face,and the concentration of dust gradually decreases during the diffusion process to the roadway outlet.The dust migration traces are basically consistent with the wind speed vector.Under the influence of roadheader,the dust flow forms a vortex above the fuse-lage,accumulating in large quantities at the driver's position and forming a large range of backflow settlement area behind the roadheader,which can easily cause secondary dust and pollute the roadway return air area.Based on this,the principle of re-gional division is proposed,determining the head-on,roadhead,driver's position,dust return area above the belt,and the range beyond 15 m from the head-on as the key dust removal areas.A semi-enclosed regional joint dust control technology combining single-area targeted dust removal and multi-zone combined dust removal is developed.A complete set of comprehensive dust control equipment is designed,composed of annular spray,air curtain dust separation device,dust removal fan,scattered fog curtain,and full-section spray.The field application results of the 42221 working face of Chaijiagou Well in Yuhua Coal Mine show that the average dust reduction rate of the roadway is 88%,and the dust reduction rate of the driver's position is 86%.