Research on the mechanism and key parameters of dust control by vortex flow in a forced-exhaust ventilation system of a coal mine driving-anchor face

To address the issue of high-concentration dust generated during the cutting process at coal mine driving-anchor faces—which disperses throughout the roadway and poses serious threats to miner occupational health—this study systematically investigates the regulation mechanism of vortex fields on dust migration under forced-exhaust ventilation systems and optimizes key ventilation parameters to enhance dust control performance. Taking the 52608 driving-anchor face in Daliuta Coal Mine as the research object, a coupled airflow-dust mathematical model was established within the Euler-Lagrangian framework. Numerical simulations were conducted to reveal airflow patterns and dust spatial distribution characteristics under varying exhaust air volumes and forced-air duct distances from the heading face. The results indicate that the jet flow from the forced-air outlet, upon impinging on the baffle, forms a dust-isolating air curtain and induces multi-scale vortex structures near the roadheader. These vortex fields suppress dust diffusion through the combined mechanisms of entrainment, blocking, and sedimentation. When the exhaust air volume Q_p < 300 m³/min, a spiral airflow field develops in the rear section of the roadway, effectively controlling dust migration. When Q_p≥300 m³/min, enhanced jet entrainment generates a large-scale recirculation zone behind the roadheader, leading to localized dust accumulation. As Q_p increases from 200 m³/min to 400 m³/min, the average dust concentration in the roadway rises from 393.5 mg/m³ to 1 224.9 mg/m³, while the breathing zone concentration increases from 40.13 mg/m³ to 43.65 mg/m³. Under a fixed Q_p of 200 m³/min, extending the forced-air duct distance L_p from 5 m to 15 m reduces the average dust concentration from 567.7 mg/m³ to 368.7 mg/m³, substantially improving dust suppression efficiency. The optimal parameter combination is determined as Q_p=200 m³/min and L_p=15 m, achieving minimum overall dust concentration and optimal control performance. Field measurements show good agreement with simulation results, providing a theoretical foundation for parameter optimization of ventilation and dust removal systems in driving-anchor faces.