Study on the influence of pressurized air jet on respiratory dust pollution in fully mechanized excavation face

Abstract

In order to optimize the dust control flow field structure of the fully mechanized excavation face in coal mine, improve the dust control efficiency of the local ventilation system, achieve energy conservation and emission reduction in the mine, and low-carbon prevention and control of dust disasters, numerical simulation was used to study the respiratory dust pollution of the fully mechanized excavation face under different pressure air jet volume and action height conditions. The results showed that the pressure air jet volume is the main factor affecting the range of respiratory dust pollution. As the volume increases, the time for dust particle aggregation to escape to the working face decreases, the dust particle aggregation area continuously moves backward, and the range of respiratory dust pollution increases; the pressure air jet action height is the main factor affecting the degree of respiratory dust pollution in the area where the excavation driver is located. As the height increases, the overall range of dust pollution slightly increases, and the average dust mass concentration in the area where the excavation driver is located shows a trend of first increasing and then decreasing. Based on this, the optimal pressurized air jet volume was determined to be 200 m3/min and the optimal action height was 2 m. After on-site application, the respiratory dust concentration at the excavation driver’s site decreased by 55.4%, and the respiratory dust mass concentration in the rear area of the excavation machine decreased by more than 73%.

Keywords

• pressure air jet
• respiratory dust
• diffusion pollution
• temporal and spatial evolution
• parameter optimization