Designing and dust control performance of internal and external dual swirl air curtain in fully mechanized excavation face

Abstract

In response to the problem of excessive dust concentration at the coal mine heading face, a new type of internal and external dual swirl air curtain generator was designed. Numerical simulations and similar tests were carried out to investigate the characteristics of the wind flow field and the dust dispersion pattern at the heading face before and after the application of the device. The results show that the dust concentration at the driver’s position decreases first and then increases with the increase of the jet outlet airflow velocity of air curtain generator, and the empirical relationship between the dust concentration at the driver’s position and the jet outlet airflow velocity is proposed, and a critical wind speed of 35 m/s was determined for effective dust control. The wind curtain generator can form a funnel-shaped swirling air curtain to prevent dust from spreading outwards, and divide the working face into two parts of dust control area and work area. The swirl air curtain reduces the diffusion speed of dust particles by 84% and has a better dust control effect for respirable dust below 5 μm; after the installation of the new swirl air curtain generator, the dust concentration at the driver’s position of the road header is reduced from 337 mg/m3 to 38 mg/m3.

Keywords

• fully mechanized excavation face
• dust control
• internal and external dual swirl air curtain
• wind flow field
• dust control effect