Performance of Automatic Sprinkler Systems for Extinguishing Incipient andPropagating Conveyor Belt Fires Under Ventilated Conditions

摘要

The U.S. Bureau of Mines conducted a study to evaluate the effectiveness ofautomatic water sprinkler systems on the suppression of incipient and propagating conveyor belt fires under ventilated conditions. Large-scale experiments were performed in a fire gallery at airflows ranging from 1.1 to 4.6 m/s. In incipient fire experiments, with 100 C, standard response sprinklers installed above and between the two strands of belting, the results showed that the sprinklers activated later, the peak heat release rates were larger, and more belting was consumed at the higher airflow. In similar experiments with 74 C, fast response sprinklers, the sprinklers activated at the same heat release rate for both high and airflows, but the peak heat release rate and amount of belt consumed was slightly higher at the lower airflow. In incipient fire experiments with sprinklers located only above the top belt, the heat release rate and amount of belt consumed was larger at the higher airflow. The propagating fire experiments showed that sprinklers located above and between the belts were effective in stopping flame propagation. Peak heat release rates and amount of belt consumed were larger at the higher airflows for both the 74 C, fast response and 100 C, standard response sprinklers. The sprinklers were equally effective at each airflow.