Research On The Spray Atomization Law And Dust Reduction Technology In Fully Mechannized Coaling Face

Mine dust is the inevitable product of coal production and processing. In order to ensure the health of miners and the safe and efficient production of coal mines, it is necessary to solve the problem that the dust concentration at personnel operating area is too high. Spray dust reduction technology is one of the most effective ways to control the dust pollution in the excavation working face of coal mines, therefore,it is of great significance to improve the efficiency of spray dust reduction. In this paper, methods of theoretical analysis, laboratory research, numerical simulation and field application were used by the author. The main research contents and results are as follows:The nozzle jet atomization and dust reduction mechanism were studied, and the mathematical model of spray dust reduction was established, then the main factors that affect the effect of dust capture were analyzed. Based on the PDI technology and the Phase Doppler laser interferometer, nozzles with good atomization characteristics were selected and applied in the spray atomization characteristic experiment.The three dimensional spatial distribution variation rules of the spray characteristics such as droplet size and velocity of the nozzles were coupling analyzed. The result shows that: when the spray pressure is 8MPa and the spray field section is 400mm-1000mm distance to the nozzle, the size of droplets is between 30pm?120?m, the axial velocity of droplets is between 20m/s?30m/s. In addition, the optimum dust reduction area of spray fields is determined through the experiment of dust reduction in spray field.The numerical simulation of air-spray two phase flow field of nozzle spray in a fixed space was carried out by FLUENT. Based on the simulation results, the formation effect of the field on the realistic condition was studied. The atomization dust reduction technology of the spraying of shearer and hydraulic support were simulated, then the spray dust reduction mechanism and the dust reduction field feature were revealed. Furthermore, the existing dust reduction technology in working face was optimized and improved, the new external spray dust settling device for shearer which can enwrap the shearer's drum was developed,and the eject spraying dust reduction device between hydraulic supports was also developed which can realize the negative pressure for dust purification. The devices were applied in Shiquan coal mine 30106 working face. The test result shows that the average dust removal rate of total dust and respirable dust in working face are 88.1% and 85%respectively, which realize the effective dust settling in fully mechanized coaling face.