Optimization on harmful gas drainage system from advance deep hole blasting for roof breaking
To minimize the influence on coal spontaneous combustion with harmful CO from roof breaking blasting in deep opening,based on laboratory experiments,we analyze the main harmful gas produced by emulsion explosives used in Kuangou Coal Mine.We also analyze CO gas diffusion mechanism after blasting based on on-site CO sensor monitoring data.We employ discharge system to drain CO gas from the blasting hole,optimize the parameters of the drainage system,and determine the optimal drainage flow rate and roadway air supply volume.The research results indicate that after blasting,CO gas mainly gushes out from the blasting hole and forms smoke cluster in the roadway,leading to CO gas volume fraction sharp change in monitoring data.CO gas slowly released through blasting holes,coal rock fractures,and coal detachment.In addition,the CO gas accumulation or adsorption in the goaf,as well as ventilation and other factors,result in CO gas volume fraction sharp change first and then slowly decreasing.The drainage system,to the maximum extent,can shorten the return air CO gas overrun time by 38 minutes and reduce the return air CO gas volume fraction peak by 45%.Under different conditions of roadway air supply volume and drainage system flow rate,the drainage effect is better when air supply is 1400 m3/min and drainage flow is 50 m3/min.Increasing the roadway air supply volume can accelerate the blasting fume migration rate and shorten CO gas overrun time,but it will also have a certain impact on the drainage system gas collector port.
deep hole blastingfumeCO gasdrainage systemharmful gas treatment
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