Research On The Migration Law Of Coal Dust In Roadways Based On Image Analysis

Occupational health of coal mine workers,especially underground workers,has always been a major difficulty in the prevention and control of occupational health industry due to the particularity and high risk of its working environment.Therefore,studying the nature of dust and the characteristics of dust disaster accidents is undoubtedly a vital part of the prevention and control of dust hazards.Based on image analysis,this paper takes coal dust particles of different particle sizes as the research object,and uses a combination of laboratory simulation tests and simulation software numerical simulation to study the law of dust migration,and provide for the prevention and treatment of pneumoconiosis Certain theoretical reference value.The main research contents and results are as follows:(1)Do analyze and summarize the recent research status of dust migration laws at home and abroad in recent years,and elaborates the generation,physical and chemical properties of dust particles in the roadway and the theoretical laws of migration.(2)Taking dust particles with a particle size range of 0-100μm and 0-150μm as the research object,the space and time self-settling test of the dust only under the action of its own gravity is carried out in a transparent acrylic cube box with a side length of50 cm.The space settlement test is used to analyze the dust distribution on 6 measuring points at different locations from the dust source within the same settlement time.In the time settlement test,the settlement time is set to three settlement time periods of 0-30 s,30-60 s and 60-90 s.Each time period has 7 measuring points to analyze the dust at the same location under different time periods.Distribution.The test shows that the measurement point closer to the dust source within the same settling time has a higher degree of dispersion of large-size dust than the measurement point farther away.As the distance from the dust source increases,the dispersion of small-particle dust gradually increases,and the dispersion of large-size dust gradually decreases,that is,the self-settling of dust is affected by gravity,and the dust with larger particle size will settle first,and the particle with smaller particle size It has a longer air suspension time(3)Taking dust particles with a particle size range of 0-100μm as the research object,a simulated tunnel test was carried out in a linear transparent acrylic box.A total of 6 measuring points are set up in the tunnel,and each measuring point uses a glass slide to collect dust particles,and the whole process is continuously ventilated.A total of 6 measuring points are set up in the tunnel,and each measuring point uses a glass slide to collect dust particles,and the whole process is continuously ventilated.The results show that with the increase of the distance from the dust source,the dispersion of large-size dust particles increases;the small-size group,especially the respirable dust(particle size less than 10μm),which is likely to cause dust occupational health hazards,The degree of dispersion did not increase with the distance from the dust source,that is,most of the dust in this part is still suspended in the air,and it is easy to be inhaled by downhole operators to cause occupational health hazards.(4)FLUENT software was used to numerically simulate the migration process of dust with a particle size of 2.5μm and 10μm in straight and L-shaped roadways under three wind speeds of 4m/s,5m/s and 6m/s,and different results were obtained.The movement and sedimentation law of dust under working conditions.The results show that the dust concentration inside the roadway is lower than that on the surrounding walls,and the high-concentration area is mainly concentrated at the lower end of the roadway,the side wall and the junction of the four corners.Under the same particle size group,the wind speed increases,and the closer to the axis of the roadway,the faster the dust concentration decreases.Under the same wind speed,the dust concentration of the large particle size group in the roadway decreases at a faster rate.In the L-shaped roadway,before the corner of the roadway,the dust deposition concentration on the bottom surface gradually increases and reaches a peak at the corner.Around the corner of the roadway,the dust concentration oscillates sharply due to the 90-degree turn of the wind flow;after the corner,the dust will gradually leave the roadway with the wind flow,and the dust deposition concentration on the bottom surface will gradually decrease to a stable level.