Fire Safety Science Digital Archive

The Actual Delivered Density (ADD) for rack-storage fires has been investigated experimentally, using an ADD apparatus equipped with a fire plume simulator. The fire plume simulator was calibrated to simulate the plumes of a 6.1-m (20-ft) high rack-storage fire of the FMRC Class I1 Commodity. Three standard upright sprinklers (17132-in. C, ID-in F & 1/2-in. G) were employed for the investigation. Empirical correlations in the form of power law for the water penetration ratio, which is the ratio of the ADD to the water density measured without fire, have been established for sprinkler-fire arrangements in which the fm was centered under one sprinkler, centered below two sprinklers on the same pipe and centered below four sprinklers. In the case of a single sprinkler operation, the water penetration ratios for a given sprinkler and fire size were found independent of the water discharge rate under the present measurement range, varying from 95 l/min to 212 l/min (25 gpm to 56 gpm).