20.500.12556/RUL-153306 Določitev eksplozijskih parametrov mlete in instant kave Determination of explosion parameters of ground and instant coffee V magistrskem delu smo analizirali dva komercialno dostopna vzorca mlete in instant kave. Vzorca smo karakterizirali; opravili smo termično analizo in izmerili porazdelitev velikosti delcev ter jima določili minimalno vžigne energijo (MVE). Vzorcu instant kave smo določili še maksimalni eksplozijski tlak (pmax) in maksimalno hitrost porasta tlaka (dp/dt)max. Meritve velikosti delcev so pokazale, da se velikost delcev vzorca mlete kave gibljejo od 26 µm do 498 µm, instant kave pa od 189 µm do 2000 µm. Vlažnost vzorca mlete kave znaša 4,83 % deleža vlage, vzorec instant kave pa vsebuje 0,86 % deleža vlage. Na osnovi pridobljenih rezultatov smo ugotovili, da je vzorec instant kave eksplozijsko občutljivejši kot vzorec mlete kave. To lahko pripišemo zelo nizki vsebnosti vlage in sami sestavi praha, saj vsebuje poleg kave še sirotko v prahu, sladkor in mleko v prahu. Območje v katerem se vname instant kava je med 300 in 600 mJ. Vrednost maksimalnega eksplozijskega tlaka je znašala 7,8 bar. Glede na izračunano vrednost deflagarcijskega indeksa prahu (Kst) uvrščamo instant kavo v prvi razred prašne eksplozije. In the master's thesis, we analyzed two commercially available samples of ground and instant coffee. We characterized the samples; we performed a thermal analysis and measured the particle size distribution and determined their minimum ignition energy (MIE). We also determined the maximum explosion pressure (pmax) and the maximum rate of pressure rise (dp/dt)max for the sample of instant coffee. Particle size measurements showed that the particle size of the ground coffee sample ranged from 26 µm to 498 µm, and the instant coffee sample ranged from 189 µm to 2000 µm. The moisture content of the ground coffee sample is 4,83% moisture content, while the instant coffee sample contains 0,86% moisture content. Based on the obtained results, we found that the instant coffee sample is more explosively sensitive than the ground coffee sample. This can be attributed to the very low moisture content and the composition of the powder itself, as it contains whey powder, sugar and milk powder in addition to coffee. The range in which instant coffee ignites is between 300 and 600 mJ. The value of the maximum explosion pressure was 7,8 bar. According to the calculated value of the dust deflagration index (Kst), we classify instant coffee in the first class of dust explosion. prehrambna industrija prašna eksplozija mleta kava instant kava food industry dust explsion ground coffee instant coffee true false false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2023-12-21 10:55:01 2023-12-21 10:55:08 2023-12-23 03:16:45 0000-00-00 00:00:00 2023 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 22136 178627075 Lobnik_Ana_-_Dolocitev_eksplozijskih_parametrov_mlete_in_instant_kave.pdf Lobnik_Ana_-_Dolocitev_eksplozijskih_parametrov_mlete_in_instant_kave.pdf 1 D1664C762E821BE2C525E90C0347EB2C dc3e2af43db0a40d790b36d2459501145c988f79f39ae25a35c56feeb8768023 0756cc72-9fe7-11ee-a263-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=179233 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0