Fire Safety Science Digital Archive

The Actual Delivered Density (ADD) of a standard sprinkler and a conventional sprinkler for rack-storage fires has been studied experimentally using an ADD apparatus equipped with a fire plume simulator. The variables examined included sprinkler discharge rates (76-212 L/min), heat release rates of the fire (0, 500, 1000, 1500 and 2000 kW), ceiling clearances (3.05, 4.57 and 6.10 m), and ignition locations (centered below one sprinkler and below four sprinklers). The sprinkler spacing was maintained at 3.05 m for all the tests. The results of the measurements indicate that the ADD decreased as the ceiling clearance is increased from 3.05 m to 6.10 m. The ADD data have been correlated satisfactorily using two parameters. One parameter corresponds to a drop size ratio and the other is the ratio of the spray momentum to the momentum of the fire plume. It is demonstrated that the ADD can be used to interpret the performance of the standard and conventional sprinklers in the large-scale rack storage fire tests conducted.