Research On Dust Diffusion Law And Spray Dust Reduction Technology In Fully Mechanized Mining Face

With the rapid improvement of mining tecnnology anu mecnamzation,(?)mining technology has been widely used in coal mining in our country.Because of the large scale of equipment and high intensity mining,high concentration dust accumulated in the mining face space and diffuses with complex air flow unpredictably,threatening the physical and mental health of underground workers seriously.Therefore,study of the law of dust movement in the fully mechanized mining face and the design of the corresponding dust reduction system have important reference significance for the on-site dust control work.This paper combines theoretical analysis,on-site measurement,numerical simulat,on and experimental research.The main research contents and results are as follows:First,the dust dispersion and concentration of the dust samples collected at each measuring points in the fully mechanized mining face were tested,and the parameters such as the particle size distribution and concentration were obtained.Based on these parameters,the numerical simulation of air-dust coupled movement law in the whole mining face space was carried out under the condition of 1.5 m/s ventilation speed,and the macroscopic movement law of air-dust in f-ully mechanized mining face is summarized.Then,According to the dust distribution law of the mining face,the combined spray system was designed.The Fluent software was used to simulate the spray effect.The simulation results show that the spray field formed by the spray system can cover most of the area of the shearer drum,covering more than 80%of the mining space,the inter-frame spray ejector can effectively suck the dusty airflow above the sidewalk,blocking the diffusion of dust,and the droplet velocity at the dust source is between 10～21m/s,the droplet size range is between 20 and 120 μm,which can receive better dust reduction effect.At last,Based on the mechanism of adding surfactant to spray water to improve the effect of atomization and dust reduction,the primary and complex tests of surfactants were designed Through the measurement of surface tension and coal dust deposition test,SDBS with a mass concentration of 0.03%adding FMEE with a mass concentration of 0.01%were selected as the optimal wetting agent for dust reduction.