Abstract: With the continuous improvement of mechanization and automation of mining operations,the underground environment is becoming increasingly complex. In order to carry out mine air purification study,the effects of urea content and air supply pressure on the treatment efficiency of multiphase pollutants were explored. A small experimental bench is built independently to simulate the multiphase pollutant diffusion system in confined space. The response surface center composite experimental method was used to establish the quadratic regression equation to analyze the interaction between experimental factors and determine the best parameters. The results show that the mass fraction of urea solution has the highest influence on the denitration rate,and the dust removal rate can be improved. The air supply pressure affects the atomization effect of the nozzle and has a significant impact on the treatment of pollutants. Excessive air supply pressure will reduce the efficiency of pollutant treatment. The urea content increases,the viscosity of the solution increases,the liquid diffusion coefficient and solubility of NO and NO 2 decrease,and the denitrification efficiency is limited. However,it has a certain effect on PM10 dust control. The interaction of the two factors has different degrees of influence on pollutant control,and has a significant impact on denitration rate and PM 10 dust removal rate,and has little contribution to PM2. 5 dust removal effect. The optimal compatibility parameters determined by response surface analysis were 6. 471% urea solution mass fraction and 0. 603 MPa gas supply pressure. The treatment efficiency obtained by the test operation was basically consistent with the predicted value. This study provides theoretical reference and data support for the further purification of multiphase pollutants in confined space.

Key words: dust prevention and control,confined space,air supply pressure,urea denitrification,response surface