The influence of fuel surface roughness on ignition in the mining industry

Fuel surfaces found in mining industries will often be torn due to wear. The environment in mining industries is distinguished by functionality and not esthetical reasons, surfaces in these environments will be rougher than surfaces found in residential homes. Performing fire experiments and testing the ignition characteristics of the fuel surface, the influence of surface roughness and surface structures should be investigated and accounted for. Ignition would occur first at any part exposed by heat transfer from several directions and we are facing a two/three-dimensional ignition scenario. In this paper the gauge depth, angle and distance was varied to depict roughness. In five out of 13 experimental cases the average ignition time showed significant difference when compared to the flat surface case, but no clear pattern was detected. No clear patterns were found when studying the twodimensional analysis results at the time of ignition. In both experiments and the two-dimensional analysis a majority of the temperatures were within the one standard deviation variation and did not show any significant difference compared with the flat case, except when comparing the gauge bottom temperatures and upper surface temperatures of the two-dimensional analysis where significant difference was found in all cases