Study on distribution characteristics of cutting dust-droplets and application of hydrodynamic dust removal in fully mechanized caving face

To address the severe dust pollution and inadequate dust suppression efficiency in fully-mechanized top-coal caving faces, this study takes the 226-upper-02 working face in Huangyuchuan Mine as a case study. Numerical simulation was employed to investigate dust migration laws during both downwind and upwind coal cutting operations. Building upon these findings, a novel hydrodynamic dust collector was developed, with systematic analysis of its mist field spatial distribution under different cutting modes. Results demonstrate that turbulent airflow generated by shearer drum cutting intensifies airflow disturbances in the mining area, inducing lateral airflow migration towards hydraulic support zones. Driven by airflow transport, dust particles diffuse towards walkway areas, with partial dispersion into goaf regions. The mist droplets generated by the hydrodynamic dust collector undergo secondary fragmentation under positive airflow dynamics, forming a mist flow with average droplet size of 140 μm and effective coverage exceeding 20 m², achieving effective enclosure of shearer drum zones. Compared with downwind cutting, the combined effects of cutting-induced turbulent airflow and ventilation during upwind cutting transform mist distribution laws from crescent-shaped to radiative band-shaped distribution near front drums, expanding effective coverage to 40 m². Field applications confirm the device's dust capture efficiency reaches 86.36%, demonstrating significant occupational health protection for frontline workers and providing valuable references for dust control technology optimization.