Migration Law and Controlling Technology for Hydrogen Sulfide in Fully Mechanized Excavation Face

In order to master the migration and distribution law of hydrogen sulfide in fully mechanized excavation face,the mathematical model of hydrogen sulfide migration and diffusion was constructed based on turbulence k-ε equation and dynamic diffusion equation,and the process of migration and diffusion was simulated,meanwhile,the comprehensive measures for the combination of foam absorption technology and water curtain purification technology were proposed.The results show that the migration process of hydrogen sulfide,which is affected by the flow field and gravity after gushing out from the working face,can be divided into three stages,namely gravity expansion,passive diffusion and uniform diffusion;hydrogen sulfide is most likely to accumulate at the lower corner of the return air side under the condition of “U” ventilation in the working face.After the application of comprehensive control measures,the volume fraction of hydrogen sulfide emission from the coal cutting decreases from 47.7×10^-6 to 6.0×10^-6,and the effective removal rate of hydrogen sulfide reaches 83.8%.