Thermal and geometrical features of jet fires

Article · January 2010with 55 Reads
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Abstract: In many severe accidents involving explosions or large fires, jet fires have been the first step of a domino effect sequence: a recent historical analysis has shown that among the accidents registered in the data bases, in approximately 50% of the cases in which it was a jet fire it caused another event with severe effects. However, the knowledge of jet fires essential features –behaviour, effects– is still rather poor. In this communication, the results obtained with relatively large jet fires (with flame length up to 10 m) are discussed. The fuel was propane, and both sonic and subsonic jet exit velocities were obtained from different outlet diameters. The distribution of the temperatures of the flame main axis was measured with a set of thermocouples. The jet fires were filmed with a videocamera registering visible light (VHS) and a thermographic camera (IR). The main flame geometrical features were analyzed as a function of the jet main variables, as well as the thermal effects (thermal radiation intensity as a function of distance). Postprint (published version)

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    The direct effects of a jet fire are among the least severe of the diverse fire accidents that can occur in industrial installations or in the transportation of hazardous materials. However, jet fires often affect equipment (e.g., a pipe or tank) that may subsequently fail and ultimately amplify the scale of the accident. This process, known as the domino effect, can have severe consequences in accidents that involve a jet fire. However, no studies have been carried out on its significance. A survey performed on data taken from several accidents databases has revealed the most frequent accident sequences. In 50% of the reported cases involving a jet fire, an additional event with severe effects also occurred.
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