As part of the master's thesis, we examined the phenomenon of explosions of aluminum alloy powders. In the introduction, we explained in detail the main parameters that affect the explosion risk during handling of flammable powders. In addition to explaining the basic concepts that need to be understood for the understanding of powder explosions, we also defined activities and processes in which aluminum powder is used/produced. At the end of the introduction, we also addressed the minimum requirements that Slovenian legislation imposes on employers in the field of explosion protection.
During the experimental part, we determined the specific surface area, volume per r, bulk and tapped density, particle size, and size distribution for two samples of aluminum alloy powders obtained from a metalworking company. By means of thermal analysis (TG/DTG/DTA/QMS), we gained a better insight into the chemical composition of our samples, their thermal stability, and the presence of other compounds. We also determined sensitivity parameters for each sample - minimum ignition energy (MIE) and minimum explosive concentration (MEC). By conducting explosions, we also obtained results of maximum explosion pressure (pmax) and maximum rate of pressure rise (Δp/Δt)max. Based on the results obtained, we concluded that the sample VLJ represents a greater explosion risk due to the presence of a higher proportion of volatile organic compounds.
In the final part of the master's thesis, we placed the obtained results of explosion risk in the context of the metalworking company that provided us with samples of aluminum alloy powders. We focused mainly on the interaction of individual results and technological factors that, in our opinion, could affect the explosion risk. The obtained results provide the basis for an objective elaboration of the explosion risk document, which is required by Slovenian legislation for employers.
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