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Case study: Aluminum‐dust explosion
Author(s) -
Ebadat Vahid,
Prugh Richard W.
Publication year - 2007
Publication title -
process safety progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.378
H-Index - 40
eISSN - 1547-5913
pISSN - 1066-8527
DOI - 10.1002/prs.10231
Subject(s) - dust explosion , pulverizer , waste management , ignition system , environmental science , dust collector , forensic engineering , engineering , metallurgy , materials science , aerospace engineering , grinding
Abstract An explosion occurred in equipment that was being used to pulverize aluminum‐alloy ingots, to form a powder with small particle size. In this process, air was recycled through a grinder, cyclone product separator, and blower, with a side stream to extract undesired dust to a dust collector. However, the concentration of dust in the circulating air stream was above the minimum explosible concentration in most of the recycle system. Ignition of this dust/air dispersion occurred as a result of an exothermic oxidation of accumulated combustible dust in the return‐air ductwork, accelerated by the relatively high temperature of the circulating air. Because the system was not protected against internal explosion, an access door on the grinder was forcibly ejected, and the door struck a hose on the liquefied petroleum gas (LPG) cylinder on a nearby forklift truck. Escaping LPG vapors—ignited by the dust fireball from the open grinder door—resulted in a flash fire that caused fatal burn injuries to the forklift driver. The primary cause of this incident was failure to adequately manage changes to the process. The causes and lessons learned as a result of this incident are described in detail, together with recommendations for improved practices to avoid similar events. Although they are related to this specific incident, the lessons are especially relevant for preventing combustible‐dust explosions. © 2007 American Institute of Chemical Engineers Process Saf Prog 2008