Boilover burning of oil spilled on water

Abstract

In-situ burning of fuels spilled on water is of interest as a means for cleaning up these spills. It also is a potential important hazard in unwanted fires. This paper reports the results of small-scale experiments that investigate the combustion of thin layers of heating oil on water, and the events that take place in this complex combustion process, which can lead to the occurrence of explosive burning, normally referred to as boilover. The work concerns primarily the influence of the initial oil-layer thickness and pool diameter on the burning rate, time to the start of boilover, burned mass ratio, boilover intensity, and temperature history of the oil and water. The temperature measurements show that the phenomenon may be due to boiling nucleation near the oil/water interface, in sublayer water that has been superheated. The violent eruptive vaporization of the water bubbles tends to atomize the oil layer above, with subsequent projection of burning droplets. The boilover intensity appears closely related to initial oil-layer thickness and pan diameter. This is discussed in terms of surface tension effects, and growth and expansion of the water bubbles at the nucleation sites.