Flammable and Combustible Liquid Spill/Burn Patterns
National Institute of Justice
INTRODUCTION
Discussions with fire investigators indicate that it would be beneficial to have the ability to predict the quantity of liquid fuel necessary to create a burn pattern of a given size. Past studies conducted with liquid fuels contained too many variables to determine the relationship between spill quantity and burn pattern area. In an effort to reduce the variables involved, and thereby understand the process of pattern formation, experiments are conducted in the laboratory under an instrumented exhaust hood, without a room or enclosure. This layout would represent a fire burning in a large space, or in an enclosure before the formation of a significant upper layer of heated combustion products. Due to the rapid combustion of fuel spills on nonporous surfaces, the results of the study may be applicable to many enclosures.
Analytical predictions and empirical data concerning the spread of liquids on ideal surfaces are available in the literature. The analytical predictions are based on perfectly smooth, level, and nonporous surfaces. The empirical data is derived from spills on very smooth level surfaces, such as epoxy-coated concrete and metal.
The floor materials of interest to fire investigators, such as wood and vinyl flooring, carpet, and unsealed concrete differ from the ideal surfaces assumed in the analytical predictions. These flooring materials contain joints and texture, and may be porous or semiporous. The spread of liquids on these surfaces is expected to differ from those measured or predicted on more ideal surfaces. This study investigates the spill and burning behavior of liquid fuels on vinyl tile, wood parquet, and carpet flooring materials. In order to provide inputs for fire modeling that can be especially useful in fire condition prediction and fire scenario evaluation, the heat release rates (HRRs) of the spill fires are measured. The liquid fuels used are gasoline and kerosene, which are commonly encountered by fire investigators in the field.