Computational fluid dynamics analysis of the dust-reduction performance of a high-speed airflow negative pressure ejector spray device

To address the issue of poor dust suppression effects of traditional spray systems in high longwall mining faces, we propose a high-speed airflow negative pressure induction spray dust suppression technology based on the Coanda effect and negative pressure entrainment and have developed a corresponding device. Using computational fluid dynamics simulations, the airflow changes inside and outside the air amplifier, the spray distribution, and the effects of various parameters on droplet size distribution were analyzed under different supply air pressures. Experiments were then conducted, in which the air velocity at different positions of the air amplifier was measured, the fragmentation condition of the liquid film near the nozzle and the change in spray angle were observed, and the experimental results of spray concentration and droplet size were compared with the numerical simulation results to verify the reliability of the simulation. Finally, through dust suppression experiments, we determined that a supply air pressure of 0.2 MPa and a spray pressure of 6 MPa were the optimal dust suppression parameters, increasing the spray coverage area and dust suppression efficiency by 66.7 % and 29.8 %, respectively. This device provides an efficient solution for dust control in the coal industry.