The theoretical analysis of gas transportation, accumulation and the airflow of mine roadways and its controlling measures

The paper has analyzed five kinds of gas diffusion patterns in the airflow of mine roadways and their characteristics, discussed the gas transport process in the roadway and in the upper corner of coal face under the condition of normal ventilation and found that the local gas accumulation took place in the field where the airflow is in the eddying flow state and in the bottom field near wall side where the main pattern of gas diffusion is molecular diffusion, which occurs danger. The main influencing factors of the gas accumulation in the local field and in the upper corner of coalface are expounded through in-situ testing and the theoretical analysis. Finally some controlling measures of the local gas accumulation are applied in Bai Ji mine.