Water Mist And Foam Multilevel Dust Suppression Technology For Dry Drilling In Coal Seam

With the increase of mining depth, in comprehensive treatment technology ofmine gas, the amount of gas drainage drilling is increasing.Dry drilling process causesmore severe dust disasters.Although traditional single dust technology can play a littlerole and is not ideal. On the basis of dust suppression of dry drilling technology, thewater mist and foam multilevel dust suppression concept is proposed.According to water mist dust suppression, jet suction dust and foam dustsuppression, water mist and foam multilevel dust suppression is designed,combiningwith the factors that affect the system at every level of dust dust effects throughexperiments to optimize the technical parameters; and finally through the laboratorysimulation experiments and field applications,dust suppression effect are analysised.The main results are as follows:（1）By the water mist and foam multilevel dust suppression system, new dustcover, hose, waterand air jet nozzles, foam dust remover, the way to foam agentadding and foaming were design.（2）According to the technical parameters with every level experiment,regulatory systems and components were optimized. Water pressure of dust cover teesranges from0.4MPa and above. Foaming agent flow is0.1~0.2L/min, the waterflow of370~650L/h, the air pressure of0.3~0.6MPa, foaming multiple of30to50times. Ejector pipe pressure is0.5MPa and above.（3）Simulation system and process steps were design, the total dust andrespirable dust concentration of Unusing and using mist and foam multilevel dustweremeasured.Total and respirable dust dust rate reached97.09%and95.57%respectively,Simulation dust suppression working well.（4）Field application of water mist and foam multilevel dust suppression systemwas established.the steps to install and operating processes on-site were and coal wereidentified. Dust concentration of drilling construction process with orifice dustsuppression device and water mist and foam multilevel dust suppression system of2504Wind Roadway in Xuehu Coal Mine were measured. Analysis showed thataverage total dust concentration of water mist and foam multilevel dust suppressioncan be reduced to35.14mg/m3.the average rate of94.25%is3.5times of spray orificerate (27.30%); average respirable dust concentrations can be reduced18.30mg/m3, the average rate of92.46%dust is3.9times of spray orifice rate (23.75%). water mist andfoam multilevel dust suppression has superiority effect in coal mine dust suppression.