Prašne eksplozije lesnega prahu

Grčar, Timotej (author), Schnabl, Simon (mentor)

Diplomsko delo je namenjeno preučevanju prašnih eksplozij lesnega prahu. Kot vzorec sta bila uporabljena prah bukve ter prah hrasta, ki sta med listavci oziroma drevesi trdega lesa najbolj razširjena po Sloveniji. Za določitev pogojev nastanka prašne eksplozije in njenih posledic se je opravilo več različnih laboratorijskih poizkusov. Za določitev oblike delcev prahu je bila izvedena vrstična elektronska mikroskopija (SEM). Vzorcema smo določili porazdelitev velikosti prašnih delcev in termične lastnosti z uporabo termične analize (TG, DTA, DTG ter QMS). Po določitvi lastnosti prahu smo se lotili določanja pogojev potrebnih za nastanek prašne eksplozije. V tem sklopu smo vzorcema določili minimalno vžigno energijo (MVE) ter minimalno vžigno koncentracijo (MEK). V zadnjem delu eksperimentalnega dela diplomskega dela pa smo določili še posledice, do katerih pride v primeru eksplozije vzorcev prahu. Določili smo maksimalen eksplozijski tlak (pmax) ter maksimalno hitrost porasta tlaka (p/t)max). Na koncu smo iz maksimalnega eksplozijskega tlaka izračunali še deflagracijski indeks Kst. Po interpretaciji rezultatov lahko sklepamo, da je parameter z največjim vplivom na verjetnost nastanka ter posledice prašne eksplozije velikost delcev prahu. Temeljna pravica vsakega delavca je, da mora biti njegovo delo načrtovano ter izpeljano na tako, da ga lahko opravlja varno ter brez negativnih vplivov na njegovo zdravje. Zato je potrebno, da v začetni fazi načrtovanja industrijskih prostorov ter procesov pomislimo na kako lahko izpeljemo operacijo na čim bolj varen način. Tveganje za prašne eksplozije se lahko bistveno zmanjša z ustreznim načrtovanjem delovnih prostorov, odsesovanja, razporeditve delovne opreme po prostoru ter grajenjem varnostne kulture zaposlenih. Za načrtovanje protieksplozijske zaščite pa potrebujemo podatke na osnovi katerih lahko določimo ukrepe s katerimi naredimo delo varno ter profitabilno.

• Language: Slovenian
• Keywords: prašna eksplozija, lesni prah, eksplozijski parametri
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2019
• PID: 20.500.12556/RUL-109683
• COBISS.SI-ID: 1538336707
• Publication date in RUL: 06.09.2019

Secondary language

• Language: English
• Title: Dust explosions of wooden dust

Abstract

The purpose of this thesis is an investigation in the wood dust explosions. For this study we decided to use the most common hardwood tree types in Slovenia forests, such as Birch and Oak trees. We used wood dust samples from these two species and did a couple of experiments in the laboratory, trying to determin the wood dust characteristics. The research started by determining the shape of wood dust particles. To get, to the results we were looking for, we used scanning electron microscope (SEM). For both wood samples we obtained the results for particle size distribution and thermal properties with the usage of thermal analysis (TG, DTA, DTG and QMS). As we got the information about wood dust properties, we started to determine the conditions that are needed for development of wood dust explosions. Our experiments helped us determine the minimal ignition energy (MIE) and minimal explosion concentration (MEC) for both Birch and Oak wood dust. In the last part, of the experiment we figured out the consequences of the explosion from the wood dust samples. We determined the maximum explosion pressure (pmax) and maximum speed of rise pressure (p/t)max). At the end of the experiment, we calculated the deflagration index Kst from the maximum explosion pressure. If we interpret the results, we can conclude, that the parameter with the largest influence on the possibility of emergence as well as consequences of dust explosion, is the size of the dust particles. The ground rule for every employee is, that his work is planed and derived in the way that is safe and not in any case harmful to his health. That is why, it is so important, that we think about industrial working place in the initial phase and how can we make the operation as safe as possible. We can lower the risks of dust explosions by approproate workspace design, ventilation, sorting the work equipment as well as building a safety culture of the employees. If we want to plan some kind of protection from the explosions, we need informations that will help determine the measures, on how to make work safe and profitable.

• Keywords: Dust explosion, wood dust, explosion parameters