Research on Relationship Between Porosity of Coal, Amount of Air Leakage and Gradient of Wind Pressure

AbstractAbout half of China's underground mining coal seams have risks of spontaneous combustion, and the condition of airflow in coal directly influences coal's nature of spontaneous combustion. In the experiment, through putting pulverized coal of certain porosity into ventilating tube and attracting wind with pipe-type ventilator at an end, the differential pressure of both ends of the ventilating tube and the ventilating volume in tube are determined. Results of experiment show that the ratio of gradient of wind pressure and amount of air leakage per unit area is stationary for coal sample of certain porosity. In the process of porosity increasing from 0.4 to 0.6 and corresponding p/q increasing from 7.248 2 to 1 840.4, as long as any one of value of p/q and porosity is fixed, the other one can be fixed. This has certain referencing value for further improving the theory of spontaneous combustion of coal and preventing technology against spontaneous combustion of coal