Study On Regularity Of Coal Dust Transport And Dust Treatment Technologies In Coal Conveyer Roadway

This thesis takes the coal belt conveyer system in roadway as the research object, by combining different methods such as theoretical analysis, experimental study, field testing and numerical simulation, to carry out the fundamental research on the regulation of transportation, sedimentation and second flying of coal dust in the coal conveyer belt roadway in different conditions,as well as the dust treatment technologies and the parameter optimization of dedusting.This thesis adopts the dilute phase gas-solid two-phase theory to study the coupled motions of the coal dust particles and gas in the coal belt conveyer roadway, respectively carries out the dynamic analysis on the dust particles in the coal belt conveyer roadway, establishes the kinetic model of the spherical dust particle subsiding motion, the mechanical model of the suspension velocity for the irregular shape dust particles, the motion equation of the dust particle suspension in roadway, and the motion equation of the dust particle group suspension in roadway.By taking the transport Lane of Wulong mine of Fuxin as the experimental roadway for sediment coal dust distribution, the sediment coal dust distribution is tested and analyzed, and the conclusion that the particle size of the sediment coal dust becoming smaller with the increasing of the transport distance, which is mainly because the coal dust of large particles can sediment by their own gravity and the turbulent diffusion has little effect on them; while the sedimentation of the small particles are more affected by the turbulent diffusion, so their sedimentation is relatively difficult, and the particle size of the sediment coal dust is mostly from 1 to 100μm, among which the middle size is from 11 to 24μm.Through theoretical analysis and experimental methods to sedimentary coal dust in roadway, the collision force is the main force of the second flying of coal dust. Meanwhile, the dust gravity and the surface tension of the droplet on the dust particles are the main factors that limiting the dust fly-up. The relationship among the wind speed of the dust fly-up, the humidity and dust particle size of the dust particles is studied, thereby providing the theoretical foundation for preventing the flying of the sediment dust by adopting spraying measurement for the coal conveyer belt system. Regularities of dust transportion and sedimentation in the coal conveyer roadways are simulated by fluid dynamics software FLUENT. Through simulation, the relationship between the wind velocity of the suspension particles and the particles size, and the relationship between the second flying wind velocity of the sediment coal dust and the particles size is established, the dust diffusion regularity at the transpersite of the coal belt conveyer system at different wind speed is also built. Meanwhile, the mechanism of the second flying of the single sediment particle and the sediment particle group is proved to be different by simulation.Based on above theoretical studies, the dedusting program of using the airtight negative pressure dust-control technology at the transfer point of coal conveyer belt as the main measurement, and using dedusting technology that the dust concentration limit control automatic spraying in the belt transportation system as the assistant dedusting measurement, while the optimization of dedusting parameters for roadway is also studied.