Abstract: The high-intensity exploitation of mineral resources has led to increasingly severe dust problems in mines,seriously threatening the safety of underground production and the occupational health of workers. Spray dust suppression technology can effectively control dust,and the quality of spray characteristics is strongly related to the final dust suppression effect. Improving the atomization effect can effectively improve the working environment. Compared with single-fluid pressure nozzles,dual-fluid atomizing nozzles have obvious advantages,but the interaction between the internal and external flow fields of the nozzle and the liquid medium is complex. The intermediate parameters in the field application have not been deeply studied,resulting in poor targeted control of spray characteristics and difficulties in achieving efficient dust suppression. Based on this,the air atomizing nozzle in the dual-fluid atomizing nozzle was taken as the research object. The influence forms and laws of two key parameters,water supply pressure and gas supply pressure,on five spray characteristic parameters,namely range,water flow rate, gas flow rate,D50 and D90 ,were studied. The grey relational analysis method was used to analyze the importance of different parameters on spray characteristics,and the sensitive indicators of different spray characteristic parameters were determined. The spray process was optimized and controlled. The study results show that water supply pressure is positively correlated with range,water flow rate and droplet size,and gas supply pressure is positively correlated with gas flow rate;range and water flow rate,gas flow rate,and droplet size are respectively sensitive to changes in water supply pressure,gas supply pressure,and liquid-gas pressure ratio. The research results can achieve targeted control of spray characteristics and provide a theoretical basis for accelerating the construction of a wet dust control system in mines. 

Key words: spray dust reduction,atomization effect,air blast atomizer,grey relational analysis,sensitive index