Effect of spray parameters on dust suppression performance at a rapid excavation working face

Dust pollution remains a critical challenge in rapid excavation faces of coal mines,and precise control of spray dust suppression is essential for improving occupational safety. Taking a rapid excavation roadway in a coal mine in northern Shaanxi as the engineering background,a gas-solid-liquid multiphase coupling model based on the Euler-Lagrange framework was established to investigate the original dust distribution characteristics and the effects of spray parameter variations (spray velocity,droplet size,and flow rate) on dust concentrations at hazardous workstations. The results indicate that under original operating conditions,dust tends to accumulate on the return-air side behind the gaps of the right-side barrier,where the dust concentration at hazardous workstations reaches up to 902 mg / m³. Spray droplet size and flow rate significantly influence the spray coverage at the excavation face,whereas spray velocity mainly enhances dust removal efficiency by intensifying dropletdust collision processes. Under the single-factor conditions,when the spray velocity is provided as 25 m / s,the mean droplet diameter is given as 50 μm,and the spray flow rate is 0. 03 kg / s,the dust removal efficiencies at hazardous workstations reach 35%,31%,and 57%,respectively. The sensitivity of spray parameters follows the order:spray flow rate > mean droplet size≈ spray velocity. A ventilation -spray experimental platform was constructed to validate the numerical model,and the maximum relative error between simulation and experimental results is 9. 7%,indicating good model reliability. This study takes hazardous workstations in rapid excavation faces as the core evaluation target and systematically elucidates the differentiated effects of spray parameter variations on dust control performance in localized high-risk areas. The findings of this article can provide a theoretical basis for optimizing spray parameters in the rapid excavation face operations.