Research On Multi-stage Atomization Dust Reduction In Fully Mechanized Excavation Face

The high concentration of dust in underground workplaces,especially the fully mechanized working face,poses a great threat to the physical and mental health of underground workers and the safe and efficient production of enterprises.Spray dust control technology is the primary dust control measure adopted in China's coal mines,and is widely used for its simple operation,good economic and dust reduction effect.However,the existing comprehensive dust control technology still has some problems,such as poor atomization effect and great limitation of dust control effect.In this paper,theoretical analysis,numerical simulation,experimental research and field application are combined to systematically study the multi-stage atomization dust control technology in fully mechanized excavation face,and the application effect of the research results is analyzed.The theory of nozzle atomization and spray dust suppression is studied.By analyzing the breakup state of liquid film,the force of particle collision process and the mechanism of droplet dust catching,the main atomizing factors affecting the efficiency of droplet dust capture are obtained.The distribution and migration of air flow field,dust field and droplet field of fully mechanized face are analyzed by Fluent software.The rules are analyzed in detail,and the results of wind-dust simulation are compared and analyzed in the field.The simulation results are basically in agreement with the actual situation in the field,and the error is small.Based on the advanced phase Doppler Laser Interferometer Technology and the experimental platform constructed by the above equipment,the atomization characteristics of the nozzle are experimented,and the types and sprays of the nozzles are synthesized.Under the conditions of spray pressure,nozzle aperture and other factors,the atomization effect of the nozzle is analyzed in detail from the macroscopic and microscopic characteristics of the droplet field,and the distribution law of droplet particle size,velocity and concentration under different parameters is determined.According to the atomization characteristics of the nozzle,the atomization nozzles suitable for different positions of the fully mechanized excavation face are selected as spraying nozzles.The selection of nozzles provides technical parameters support;according to the numerical simulation of dust distribution and migration law,combined with the optimization of nozzle atomization characteristics experimental nozzles,the multi-stage atomization dust suppression technology principle is designed,and according to the characteristics of dust production at different locations of fully mechanized excavation face,the suitable atomization dust suppression device is designed.At the same time,the equipment and roadway of 3505 fully mechanized excavation face in Liangbaoshi Coal Mine are combined.In the meantime,the optimized application of the equipment in the different positions of the fully mechanized working face has effectively improved the dust of the 3505 working face,and the average dust reduction rate has reached 83.1%and 82.5%respectively,which is 23.6%and 22.4%higher than that of the original spray dust reduction method.It effectively reduces the dust concentration of the heading face and improves the efficiency of the atomization and dustfall,thus ensuring the safe production and operation personnel of the mine.