Abstract: The belt conveyor transfer point is one of the most severely dust-polluted areas in underground mines,characterized
by multiple dust sources and rapid dispersion,posing significant threats to occupational health and safety. Conventional
spray techniques are limited by large droplet sizes,insufficient coverage,and strong susceptibility to airflow disturbances,making
them ineffective for capturing fine particulate dust. To address the complex airflow conditions in underground environments,
a coupled flow field-dust field model of the transfer point was established using COMSOL numerical simulation. The airflow variation
characteristics and dust migration features were systematically analyzed. The results indicate that the airflow field in the
transfer area exhibits a distinct stratified structure,where velocity gradients and local vortices jointly drive particle-size-dependent
migration:coarse particles predominantly settle under gravity,while fine particles are transported by the airflow and tend to
accumulate in the breathing zone and upper regions. Based on these findings,a pneumatic fog curtain dust control technology
integrating supersonic atomization and a spiral pneumatic structure is proposed. Through the combined effects of fine droplet
capture and spiral airflow entrainment,the proposed system effectively interferes with dust migration paths and enhances source
control. Comparative experiments demonstrate that the pneumatic fog curtain outperforms conventional spray systems in terms of
wind resistance,coverage,and dust suppression efficiency. Field application results show that,under a pressure of 0. 4 MPa,the
maximum deflection angle of the fog curtain does not exceed 6. 1°. The total dust concentration at the transfer point is reduced
by 43. 28%,the dust suppression efficiency exceeds 90% at 10 m downwind,and the respirable dust concentration decreases to
1. 2 mg/ m3,with an overall efficiency of 86. 78%. The proposed technique provides an effective solution for dust control at coal
mine transfer points and contributes to improving mine working environments and occupational health conditions.

Key words: spray dust suppression,transfer point,dust movement laws,air-powered fog curtain,occupational health