Effects of turbulent airflow from coal cutting on pollution characteristics of coal dust in fully-mechanized mining face: A case study

In order to investigate the influences of turbulent airflow disturbance from coal cutting on pollution characteristics of coal dust, the airflow migration and the coal dust dispersion was numerically simulated. For its research results, the local spray closure dedust technique was proposed and field test was carried out in the No. 905 fully-mechanized mining face of Jiangzhuang Coal Mine owned by Shandong Energy Zaozhuang Mining Group Co., Ltd. The results demonstrated that the turbulent airflow from coal cutting was quite stable, which can hardly be blown away by the ventilation airflow at a mean initial velocity of 1.3 m/s. There was an interaction between turbulent airflow from coal cutting and system ventilation airflow, resulting in further deviation of airflow. The velocity component along the positive direction of Y-axis was mainly responsible for the formation of deviated airflow and its migration from shearer haulage space to footway space. The regions with a mean deviated velocity component of over 0.3 m/s corresponded to heavy pollution regions in which the mean dust concentration exceeded 100 mg/m3. Compared with the original dust suppression measures, the local spray closure dedust technique can enhance the removal ratio of respiratory dust by an average of 26.7% and the coal dust concentration are less than 50 mg/m3 where the drum drivers and support moving worker operated.