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V sklopu magistrskega dela smo obravnavali fenomen eksplozij prahov aluminijevih zlitin. V uvodnem delu smo podrobno obrazložili glavne parametre, ki vplivajo na eksplozijsko tveganje tekom rokovanja z gorljivimi prahovi. Poleg obrazložitve osnovnih pojmov, ki jih je potrebno poznati za razumevanje prašnih eksplozij, smo definirali tudi dejavnosti ter procese, v sklopu katerih se uporablja/proizvaja aluminijev prah. Za konec uvodnega poglavja pa smo obravnavali še minimalne zahteve, ki jih s področja protieksplozijske zaščite delodajalcem nalaga slovenska zakonodaja. Tekom eksperimentalnega dela smo dvema vzorcema prahov aluminijevih zlitin, pridobljenih iz kovinskopredelovalnega podjetja, določili specifično površino, volumen por, nasipno in zbito gostoto ter velikost in porazdelitev velikosti delcev. S termično analizo (TG/DTG/DTA/QMS) smo dobili boljši vpogled v kemijsko sestavo naših vzorcev, njuno termično obstojnost ter prisotnost drugih spojin. Vsakemu vzorcu smo določili še parametre občutljivosti – minimalno vžigno energijo (MVE) ter minimalno eksplozijsko koncentracijo (MEK). Z izvajanjem eksplozij smo pridobili tudi rezultate maksimalnega eksplozijskega tlaka (pmax) ter maksimalno hitrost porasta tlaka (Δp/Δt)max. Na osnovi pridobljenih rezultatov smo prišli do zaključka, da večje eksplozijsko tveganje zaradi prisotnosti večjega deleža hlapnih organskih spojin predstavlja vzorec, pridobljen iz proizvodnega obrata Ljubljana. V zaključnem delu magistrskega dela smo pridobljene rezultate postavili v kontekst kovinskopredelovalnega podjetja, ki nam je odstopilo vzorca prahov aluminijevih zlitin. Osredotočili smo se predvsem na medsebojni vpliv posameznih rezultatov ter tehnološke dejavnike, ki bi po našem mnenju lahko vplivali na eksplozijsko ogroženost. Pridobljeni rezultati predstavljajo osnovo za izdelavo elaborata eksplozijske ogroženosti – strokovne podlage, katere izdelavo delodajalcu narekuje zakonodaja Republike Slovenije. 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. |
