Plastic pool fires

Abstract Experimental results relating flame radiation feedback mechanisms to the burning behavior of 51 mm-thick, solid, horizontal, square, polymethyl methacrylate (PMMA) pools are discussed. Data for sizes ranging from 25 mm × 25 mm to 1.22 m × 1.22 m show that the burning rate per unit surface area of plastic pool fires increases with scale and is dominated, at the larger scales, by thermal radiation from the flames. The total radiative power output of the flames represents 42% of total heat release rate of the larger PMMA fires. Local burning rates for the larger plastic pools are maximum at pool center, corresponding to maximum radiative heat transfer from the flames, and decrease monotonically to the edge of the pool. Relatively long time periods are required to establish steady burning in the intermediate sized pools. The long “burn-in” time to reach steady state is associated with increasing radiative heat flux from the flames to the pool with time. The magnitude of the time-dependent radiative heat flux to the pool is calculated on the basis of a one-dimensional analysis for a semi-infinite slab. The variation of local burning rates along the pool surface is formulated in terms of a cylindrical flame model. Physical implications of the assumptions made in the analysis and their limitations are reviewed critically.