Influences of ventilation conditions of fully mechanized excavation face on dust-resistance effect of radial swirling air curtain

Abstract

In order to improve the dust-resistance efficiency of radial swirling air curtain in fully mechanized excavation face and prevent high-concentration dust pollution on the working area, the method of combining numerical simulation and engineering measurement is used to analyze the influences of ventilation conditions on dust-resistance rule of radial swirling air curtain. The results show that as the distance between the air curtain and the working face increases, the radial air volume of the air curtain device increases, and the pressure-exhaust ratio of the ventilation system decreases, the radial swirling air curtain is easier to transform into an axial direction with uniform air volume and velocity distribution during the migration process, and the dust pollution degree reduces as well. Fitting the quantitative relationship between the high-concentration dust diffusion distance and various ventilation conditions, combined with the actual production conditions, it is determined that the better ventilation conditions for the radial swirling air curtain dust resistance are as following: the air curtain is 30 m away from the working face, the radial air volume of the air curtain device is 270 m3/min and the pressure-exhaust ratio of the ventilation system is 0.8. Through engineering measurement of the simulation result, the validity of the numerical simulation was verified. The dust concentration ofthe tunneling driver’s section was reduced to 35.5 mg/m3, and the air curtain dust resistance efficiency reached to 90.5%.

Keywords

• fully mechanized excavation face
• ventilation condition
• radial swirling air curtain
• dust resistance rule
• parameter optimization