Numerical simulation of respirable dust transport law in fully mechanized excavation face
WANG Jianguo
WANG Bolan
HAN Min
Abstract：Due to its small particle size,respirable dust is more likely to enter the deep respiratory tract,and it is difficult to settle in the roadway for a long suspension time.In order to improve the problem of serious respirable dust pollution on the excavation sur-face,we conducted a study on the driving face of 42207 auxiliary transport roadway in Liangshuijing Mine.Based on the theory of gas-solid two-phase flow,the air flow condition and the migration and distribution characteristics of respirable dust in the tunnel un-der press-in ventilation were studied by numerical simulation.The simulation results showed that air flow plays a major role in dust migration within the roadway and can be divided into three regions:vortex region,jet region and reflux region.Under single air flow action,dense distribution of dust varies across different regions.At the driving face,high-speed jets carry large amounts of respir-able dust which gather between working faces and driving machines resulting in an average concentration of about 2 300 mg/m3 at the driving face.In the vicinity of the TBM,that is,within the first 15 m of the tunnel,most of the dust particles are affected by the eddy currents above and behind the TBM,causing most of the particles to accumulate at the eddy currents,while the rest settle at the bottom of the tunnel,and the other part continues to move backward along the left side wall of the tunnel under the action of wind currents.The average mass concentration of the dust on the left side of the tunnel reaches more than 1 000 mg/m3.When the air flow field is far away from the tunneling surface and without the obstruction of the tunneling machine,the airflow field diffuses and the wind speed decreases,but a large number of particles still float in the roadway for a long time and are difficult to settle due to the small particle size of the exhaled dust.
Keywords：fully mechanized excavation facepress-in ventilationrespirable dustair flow characteristicmigration law
Publication Date：2025-06-20
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 71-78 )