Spread rate of flammable liquids over flat and inclined porous surfaces

Very large quantities of flammable substances are produced, transported, and refilled across the world. Of these some, like gasoline and diesel, are liquids at normal temperature and pressure while some others – like liquid petroleum gas (LPG – are pressure liquefied gases. Ever so often accidental spills of these chemicals occur. While some spills are contained before they could do much damage, many others catch fire and often also lead to massive explosions. Indeed, accidental spills have been the initiators of the majority of industrial disasters the world has seen. Given the exceptional importance associated with the containing and controlling of accidental spills, it is essential to understand the factors which effect the spill dynamics so that ways to reduce the risk posed by such spills can be devised. But even as a great deal of work has been done on the dynamics of spills occurring on flat surfaces, little past effort is on record pertaining to the study of spills occurring on inclined surfaces. This is surprising because the spillways actually provided in the industries for large storage tanks invariably have downward slope to enable quick drainage of the flammable liquid away from the storage tank in the event of an accidental leak. The present work is an attempt to make some contribution towards the understanding of the dynamics of spillage of flammable liquids on inclined surfaces. When accidental spills occur in the open – during transportation by road, railroad, or pipeline – the receiving surfaces can be porous and the liquid can percolate down, making environmental contamination that much difficult to remediate. To incorporate this aspect in the present study we have chosen porous surfaces and studied the dynamics of the spill of three different flammable liquids on them at angles of inclination varying from zero to 20°.