During the dry drilling process

wind slagging system discharges the cuttings along the annular slit of the drill at a high speed

which generates high concentration dust. In order to effectively control dust pollution during dry drilling in coal seam

the main factors that influence dust distribution were exploved and the drilling technology parameters with low dust concentration were determined. The numerical simulation of dust concentration distribution under different boundary conditions was carried out by using SolidWorks and DesignModeler to build models

using Mesh to divide the grids

using Fluent to calculate

and using CFD-Post to postprocess. Compared with field measurement of dust concentration

the simulating results basically agreed with the measured data. The result indicates that the velocity of pyramidal compressed air attenuated rapidly after the ejection from cyclic slit

and large drillings settled immediately near the orifice

while fine particles floated in the air and continued to spread with wind. Dust concentration in drilling field along the way rose sharply to a maximum value first

then dropped rapidly

and finally decreased gradually. In the horizontal direction

the dust concentration in the middle of the roadway was lower than that in the middle of the machine road

which had the highest dust concentration

and that in the center of the sidewalk was the lowest. In the vertical direction

the dust concentration distribution showed a feature that it was high in the middle and low in the upper and lower sides. The five main factors that affected the dust distribution were the wind speed in drilling field

the drill rod rotation speed

the pressure of the gas supply

the drill rod type

and the drilling type. When the wind speed was 0.5 m/s

the rotation speed was 2 r/s

and the gas pressure was 0.8 MPa

a good dust reduction effect was achieved by using outer flat drill rod to drill into the pre-drainage borehole of tilted parallel. The results can effectively guide the field operation of drilling and the development of dust control devices.