Behavior of Methane Gas and the Effects of an Additional Forcing Duct in Combined Auxiliary Ventilation System at Heading Faces with a Road Heading Machine

摘要

Auxiliary ventilation is required to remove dust and gases generated at heading faces in underground coal mines. Currently, quantities of dust and gases are increasing due to high development rates and large cross sectional areas of the roadways. Combined ventilation system is being adopted in order to remove such dust and gases more efficiently. The optimum design of the location of ventilation ducts and of airflow volume is very difficult. The flow pattern in the surrounding face of roadway in the coal seam by using combined ventilation system is very complicated. The authors have investigated the airflow patterns in combined ventilation system and the behavior of methane gas by visualization experiment with reduced scale models. This paper discusses the results of the examinations on optimum ventilation conditions to remove effectively methane gas generated in the heading faces where a cutting machine is working. During the experiment, additional forcing duct is set up with a view to preventing methane gas from concentrating at the overlapped zone and the effect of the forcing duct is investigated.