Numerical simulation on the distribution characteristics of dust-droplet field during support movement in a fully-mechanized mining face and related engi-neering applications

In order to enhance the spraying dedusting efficiency during the support movement process in a fully-mecha- nized mining face,this study employed computational fluid dynamics (CFD) for conducting a numerical simulation on the airflow-dust field and airflow-droplet field in the No. 213 fully-mechanized mining face of the Qiwu Coal Mine,Chi- na. The aim of simulation was to ascertain the migration and distribution rules of dust particles and droplets under air flow. Accordingly,the dust suppression performances of unidirectional and bidirectional nozzles were compared by com- bining field measurement results and numerical simulation data. The results show that a uniform arrangement of three nozzles on the front canopy along the inclination direction of the mining face,and a uniform arrangement of four nozzles on the top beam along the normal direction of the coal wall for each of five hydraulic supports,can generally cover most of the dust particles that are produced during the support movement in this fully-mechanized mining face,with a dust suppression rate of up to 85． 47% . Compared with the results using traditional unidirectional spraying,the dust sup- pression rate using the proposed combined spraying method can be enhanced by 31. 65% . This improvement to the spraying technique can enhance dust prevention and control performances during support movement in a fully-mecha- nized mining faces,and has a major influence in ensuring the safe production in mines and the occupational health and safety of miners.