Effect of fuel ratio and flame initiation delay on the rate of flame spread over a porous bed wetted with a flammable liquid

Accidental spills of combustible liquids over inert porous solids are major fire hazards and pose significant safety concerns in industrial settings and residential areas. An experimental investigation was conducted to explore the rate of flame spread over an unconsolidated porous bed wetted with different combustible fuel ratios under various conditions. Propanol and sand particles ranging from 0.5 to 5 mm were used as the liquid fuel and porous bed, respectively. A video cinematography technique was applied to determine the rate of flame spread and combustion behaviour. Results corresponding to the flame spread for different fuel ratios show that the rate of flame spread depends on the fuel ratios as well as ignition delay. In the case of ignition without delay the rate of flame spread increases as the fuel ratio increases. It was observed to increase from 1.38 m/s to 1.5 m/s for the ratios of 0.1 and 0.15, respectively. In addition, the rate of increase is larger for beds containing finer particles in compare with those coarser particles