Research on dry-type dust removing device of borehole based on pressure air dust control and ring slot ejecting technology

In view of the difficulties in dust control and dust removal in the gas drainage borehole of soft broken coal seam in coal mine, a new technology of dust control by air pressure at orifice and dry dust removal by annular seam injection is proposed. By means of experiment and numerical simulation, the dust control structure and parameters, dynamic components of dust collector and classification dust removal technology are studied. The research results show that: when the drilling slag discharge pressure is 0.3 MPa and the dust control pressure is 0.5 MPa, the dust control efficiency can reach 99.61%; the over efficiency of cyclone dust removal device reaches more than 92.9%, and the resistance is less than or equal to 620 Pa; when the filtering wind speed of bag filter is 1.1 m/s, the dust removal efficiency reaches 99.95%. The field application results show that the dust fall within 1 m around is more than 99.3% in the construction process of directional drilling in broken soft coal seam, which has achieved good field application effect.