Parametric studies to maximize the dust protection performance of the two-level manifold canopy air curtain and computational fluid dynamics modeling

Prolonged exposure to high concentrations of respirable coal mine dust causes coal workers’ pneumoconiosis and silicosis. Underground coal mine roof bolter operators are more prone to these ailments due to their elevated exposure to dust. The canopy air curtain (CAC) was developed by NIOSH to alleviate their exposure. The CAC supplies filtered air over their breathing zone that dilutes the high coal dust concentrations and provides for an impenetrable air curtain. Many studies attempted to improve the CAC design, but field tests show variable dust control efficiencies. The non-uniform airflow distribution across the plenum and ineffective perimeter flow are the major impediments. This study, therefore, systematically redesigns the CAC for an optimized flow distribution. The Simplex Evolutionary Operational (EVOP) optimization algorithm was applied to the geometrical parameters. Computational fluid dynamics (CFD) simulations were run at each iteration of the algorithm. The combination of these methodologies led to an enhanced uniformity of the airflow distribution across the plenum to achieve the best possible dust suppression efficiency. A lab experiment using a physical model was used to validate the computer models and validate the efficacy of this parametrically designed CAC.