Določitev minimalne vžigne energije cinkovega in železovega prahu

Prelesnik, Nika (author), Novosel, Barbara (mentor)

Prašne eksplozije predstavljajo resno nevarnost za predelovalno in obdelovalno industrijo, kjer se uporabljajo ali proizvajajo gorljivi drobni delci različnih materialov. To vključuje lesno, kovinsko predelovalno in obdelovalno industrijo, farmacevtsko industrijo, premogovništvo, živilsko industrijo ter druge. Na nastanek, razvoj in posledice prašne eksplozije vplivajo številni dejavniki. Za obvladovanje tveganja prašnih eksplozij moramo razumeti vzrok nastanka in dejavnike, ki vplivajo na njeno napredovanje. Ključna informacija za vrednotenje posledic prašne eksplozije je minimalna vžigna energija, s pomočjo katere lahko ocenimo možnost nastanka prašne eksplozije in uvedemo ustrezno protieksplozijsko zaščito. V diplomskem delu bodo predstavljene kemijsko-morfološke lastnosti cinkovega in železovega prahu in njihov vpliv na minimalno vţigno energijo in posledično na nastanek prašne eksplozije. V diplomskem delu so predstavljene lastnosti cinkovega in železovega prahu. Rezultati so podani za komercialno dostopen vzorec in vzorec velikostne frakcije manjše od 56 μm. Vzorcem je bila določena velikost in porazdelitev velikosti delcev, specifična površina z metodo BET in termične lastnosti z uporabo termične analize. Eksplozijski parameter, ki smo ga določali je bila minimalna vžigna energija. Na podlagi rezultatov sem ugotovila, da v komercialno dostopnem vzorcu cinkovega in železovega prahu prevladujejo velikostne frakcije manjše od 56 μm. Železov prah predstavlja večjo nevarnost za vžig in nastanek prašne eksplozije, saj ima v povprečju manjše delce in pri meritvah minimalne vžigne energije smo določili območje 100 mJ < MVE < 300 mJ. Glede na literaturne podatke je MVE železovega prahu 150 mJ in sodi v območje MVE, ki smo ga eksperimentalno določili. Za cinkov prah smo določili, da je minimalna vžigna energija višja od 1000 mJ. Literaturna vrednost MVE za cinkov prah pri 200 mJ se tako bistveno razlikuje od eksperimentalno določene vrednosti. Informacija za velikost delcev ni podana. Sklepam, da so bili podatki iz literature za cinkov prah pridobljeni z uporabo bistveno manjših delcev, kot v našem primeru.Diplomsko delo daje podrobnejši pregled kako lahko manjše frakcije delcev vplivajo na minimalno vžigno energijo v primerjavi s širšim razponom velikosti delcev železovega in cinkovega prahu.

• Language: Slovenian
• Keywords: prašna eksplozija, minimalna vžigna energija, cinkov prah, železov prah
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2023
• PID: 20.500.12556/RUL-151578
• COBISS.SI-ID: 174474499
• Publication date in RUL: 10.10.2023

Secondary language

• Language: English
• Title: Determining the minimum ignition energy of zinc and iron dust

Abstract

Dust explosions pose a serious safety risk to the processing and manufacturing industries where fine particles of various materials are used or produced. This includes the wood and metal processing and metalworking industries, the pharmaceutical industry, the coal industry, the food industry and many others. The formation, development and consequences of a dust explosion are influenced by many factors. To manage the risk of dust explosions, we need to understand the cause and the factors that influence its progression. The key information for evaluating the consequences of a dust explosion is the minimum ignition energy, with the help of which we can assess the possibility of a dust explosion and introduce appropriate explosion protection. The diploma thesis will present both the chemical and morphological properties of zinc and iron dust and their influence on the minimum ignition energy and consequently, on the formation on a dust explosion. The thesis examines the properties of zinc and iron powder. Results are given for a commercially available sample and a sieved sample containing size fractions less than 56 μm. The samples were determined by particle size and size distribution, specific surface area by BET method and thermal properties using thermal analysis. The explosion parameter determined was the minimum ignition energy. Based on the results, I found that size fractions smaller than 56 μm predominate in the commercially available sampels of zinc and iron dust. Iron dust poses a greater risk of ignition and dust explosion, as it has smaller particles on average, and the range of MIE when measuring was 100 mJ <MVE <300 mJ. According to the literature, the iron dust MVE is 150 mJ and belongs to the MVE range determined experimentally. For zinc dust, the minimum ignition energy was determined to be higher than 1000 mJ. The literature value of MVE for zinc dust at 200 mJ thus differs significantly from the experimentally determined value. No particle size information is given. I conclude that data from the zinc powder literature were obtained using significantly smaller particles than in our case. The thesis provides a more detailed overview of how smaller particle fractions can affect the minimum ignition energy compared to a wider range of iron and zinc dust particle sizes.

• Keywords: dust explosion, minimum ignition energy, zinc dust, iron dust