Construction of a self-excited foam dust suppression system and study on gas–liquid regulation mechanism in coal mining face

Coal mining faces persistently face the challenge of excessive dust concentrations, posing significant occupational health risks. This study proposes a self-excited foam dust suppression system integrated with a gas–liquid regulation mechanism. Through a combination of numerical simulations and experimental validation, the research focuses on three aspects: compound optimization of fine wet foam dust suppressants, multi-parameter collaborative regulation of bubble generation devices, and on-site application efficacy evaluation. Orthogonal experiments identified the optimal dust suppressant formulation as 0.01% dioctyl sulfosuccinate sodium salt + 0.05% alkyl polyglucoside + 0.1% alcohol ether sulfate. Numerical and experimental results demonstrated that under a water supply pressure of 3.0 MPa, a suction pipe diameter of 10 mm, and an L-shaped tee structure, the system achieved an optimal negative pressure of −753.02 Pa, a jet velocity of 9.627 m/s, and a gas–water ratio (λ) improvement of 9.73 compared to conventional configurations. Field application at the 823 coal mining face in Yuandian No. 1 Coal Mine showed total and respirable dust suppression efficiencies of 78.1% and 81.7%, respectively, representing 35.7% and 42.3% enhancements over traditional spray systems. This study innovatively integrates gas–liquid directional regulation and composite wetting enhancement technologies, providing theoretical and technical insights for dust control in coal mining environments.