Research on the dust transportation law and cyclone air curtain dust control technology of coalface

Based on the coal mine comprehensive excavation face using mixed ventilation in the roadway caused by improper flow of dust large-scale gathering phenomenon for in-depth study, in order to seek the dust distribution law and reduce the concentration of dust gathered in the roadway for the purpose of using Space claim to establish a simple model, Ansys fluent software for numerical simulation, the simulation results show that the dust is filled with dust in the entire roadway, the driver's position at the top and the return side corner of the corner of the serious dust gathering. The simulation results show that the dust is filled in the whole tunnel, and the top of the driver's position and the corner of the return air side have serious dust gathering. In order to improve and optimize the hybrid ventilation device, on the basis of the original hybrid ventilation, the radial outlet is added to the inlet tube to make a vertical air curtain to intercept the spread of dust, and the mobility of the air curtain is used to cooperate with the air extraction outlet to form a cyclone air curtain that moves towards the face of the comprehensive excavation to actively inhibit the dust. And selected pedestrian breathing zone and driver position as the reference point of the four factors affecting the concentration of dust in the roadway were single-factor optimization and multi-factor integrated control, according to Box-Behnken principle to establish the optimization scheme, the optimal solution to inhibit dust is: the width of the guide channel is 0.04m, the height of 0.09m, the axial diameter out of the wind ratio of 0.5, the diameter of the outlet cylinder is 1.2m. After optimization, the dust concentration in the breathing zone of pedestrians decreased from 1.19-10-4 Kg/m3 to 4.33-10-5 Kg/m3, which is a 63.6% decrease in dust concentration. The dust concentration at the driver's position decreased from 1.78-10-4 Kg/m3 to 3.85-10-5 Kg/m3, a 78.2% decrease in dust concentration. The influence of the four main factors on the respiratory zone of pedestrians is in the order of axial diameter air volume ratio > caliber > width of the deflector channel > height of the deflector channel; and the influence on the dust concentration at the driver's position is in the order of axial diameter air volume ratio > height of the deflector channel > width of the deflector channel > caliber. Finally, according to the similarity principle and the similarity criterion, the appropriate model rate was selected to construct a similar experimental model for ventilation and dust control, and the optimal airflow regulation program was used for air curtain dust control experiments, and the experimental results basically matched with the numerical simulation results, with an error of less than 5%.