Research on dust control technology of dry directional drilling in soft-fragmentized coal seam

In view of the problem that dry directional drilling of soft-fragmentized coal seam produces large amount of dust and serious dust diffusion, a non-contact dust control technology scheme for drilling holes was proposed, and a prototype of dust collection cover was designed and developed. The process parameters affecting the dust control effect, such as the gap width between the dust collection cover and the drill rod, the air gap width of the sealing device, and the pressure of the dust control air curtain, were studied experimentally, and the optimum process parameters were obtained in this paper. The research results show that:when the gap width between the drill rod and the dust collection cover is 2.0 mm, the air gap width is 0.2 mm, the slag discharge gas pressure is 0.3 MPa, and the pressure of the dust control air curtain is 0.5 MPa, the dust mass concentration is reduced from 540 mg/m³ to 15 mg/m³, the dust control efficiency reaches 97.2%. The field application results show that the dust control efficiency can reach 98.3% after using the dust collection cover, and the dust control effect is good.