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Pyrolysis, ignition, and fire behaviour of agricultural food grains
Thesis (PhD)--Stellenbosch University, 2023.
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| Format: | Thesis |
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Stellenbosch : Stellenbosch University
2023
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| _version_ | 1867613959910064128 |
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| access_status_str | Open Access |
| author | Oguaka, Anene Basil Chukwuzubelu |
| author2 | Walls, Richard Shaun |
| author_browse | Oguaka, Anene Basil Chukwuzubelu Walls, Richard Shaun |
| author_facet | Walls, Richard Shaun Oguaka, Anene Basil Chukwuzubelu |
| author_sort | Oguaka, Anene Basil Chukwuzubelu |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (PhD)--Stellenbosch University, 2023. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/129308 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:44:25.612Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2023 |
| publishDateRange | 2023 |
| publishDateSort | 2023 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/129308 Pyrolysis, ignition, and fire behaviour of agricultural food grains Oguaka, Anene Basil Chukwuzubelu Walls, Richard Shaun Flores-Quiroz, Natalia Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering. Grain -- Processing -- Africa Fire ecology -- Africa Agricultural informatics -- Africa Flame spread -- Africa Food delivery services -- Africa Pyrolysis -- Africa Agriculture -- Safety measuresen -- Africa Temperature measuring instruments Thermogravimetry UCTD Thesis (PhD)--Stellenbosch University, 2023. ENGLISH ABSTRACT: Large quantities of agricultural food grains in storage, transport, and processing facilities have been involved in some disastrous fires around the world for decades. These accidents pose a serious threat to lives, livelihoods, the environment, and food security. As the world population increases, these facilities will only become larger and more numerous to meet the needs of food supply to society. Currently, there is a dearth of knowledge of the fire characteristics such as ignition temperatures, and heat release rates. associated with food grains, particularly those grown in Africa. This lack of data implies there is a shortage of fundamental information to guide engineers to optimally design and operate such facilities safely. This study aimed to experimentally determine, compare, and evaluate the fundamental fire characteristics of African agricultural food grains. Relationships that these characteristics may have with other physical properties such as bulk density, bulk porosity, and oil content were considered. Cone calorimeter, thermogravimetric tests, radiative piloted ignition studies, and smouldering tests were conducted on nine different food grains sourced in Cape Town, South Africa. The nine food grains studied were, cowpea, lentils, millet, soybean, flax (linseed), unshelled peanut, sunflower, shelled peanut, and sesame. The results showed that these grains have different fire characteristics and thermal hazards but mostly varied with oil content, grain particle size, and bulk porosity. The parameters obtained include heat release rate, effective heat of combustion, mass loss, critical heat flux, time to ignition, peak heat release rate, total heat release and time to peak heat release rate. Analysis conducted based on these parameters indicates that overall thermal fire hazards are approximately proportional to oil content. The ignition parameters obtained included thermal inertia which was almost the same for all food grains. However, the thermal response parameter was a more discriminating ignition parameter and suggested a proportionality with particle size. Based on the activation energies, oil grains require less energy to decompose than non-oil grains. Smouldering tests have shown that grains with higher bulk porosity have a greater tendency to propagate and transition to flaming, and this is due to larger voids allowing greater airflow required for flaming combustion. These findings indicate that differences in fire characteristics exist across the food grains. As these characteristics can be related to certain other properties that are easily known or determined, the behaviour of other similar grains can be inferred. Application of this knowledge will contribute towards reducing the incidence of fire in food grain facilities thus avoiding the consequences of loss and environmental pollution. Additionally, the data can be used in validating computational models for fire simulation or in performance-based fire design of such facilities. AFRIKAANSE OPSOMMING: Groot hoeveelhede landbou graankorrels in bergings-, vervoer- en verwerkingsfasiliteite was betrokke by sommige rampspoedige brande regoor die wêreld. Hierdie ongelukke hou 'n ernstige bedreiging in vir lewens, lewensbestaan, die omgewing en voedselsekerheid. Soos die wêreldbevolking toeneem, sal hierdie fasiliteite slegs groter en meer word. Tans is daar 'n gebrek aan kennis van die brandeienskappe, soos ontbrandings temperatuur, kritieke hitte vloed, ens.,wat met voedselkorrels geassosieer word, veral dié wat in Afrika verbou word. Hierdie gebrek aan data impliseer dat daar 'n tekort aan fundamentele inligting is om brandveiligheid ingenieurs te begelei om fasiliteite optimaal te ontwerp en veilig te bedryf. Hierdie studie het ten doel gehad om die fundamentele brandeienskappe van Afrika-landbou graankorrels eksperimenteel te bepaal, te vergelyk en te evalueer. Verwantskappe wat hierdie eienskappe kan hê met ander fisiese eienskappe soos massadigtheid, massa porositeit en olie-inhoud is oorweeg. Kegel kalorimeter, termometriese toetse, straling bestuurde ontsteking studies en smeul toetse is op nege verskillende graankorrels uitgevoer. Die nege graankorrels wat bestudeer is, was: swartbekboontjies, lensies, giers, sojabone, vlasaad (lynsaad), ontdopte grondboontjies, sonneblom, grondboontjies met doppe en sesamsaad. Die parameters wat in hierdie werk verkry is, sluit in hittevrystellingstempo, effektiewe verbrandingshitte, massaverlies, kritieke hitte vloed, tyd tot ontsteking, piek hittevrystellings tempo, totale hittevrystelling en tyd tot piek hittevrystellingstempo. Ontledings gebaseer op hierdie parameters dui daarop dat algehele termiese brandgevare ongeveer eweredig is aan olie-inhoud. Die ontstekingsparameters wat verkry is, het termiese traagheid ingesluit wat byna dieselfde was vir alle graankorrels. Die termiese responsparameter was egter 'n onderskeidende ontstekingsparameter en het 'n proporsionaliteit met partikelgrootte voorgestel. Op grond van die aktiveringsenergie, het olie graankorrels minder energie nodig om te ontbind as nie-olie graankorrels. Smeultoetse het getoon dat graankorrels met hoër massa porositeit 'n groter neiging het om te versprei en na vlamme oor te gaan, en dit is as gevolg van groter leemtes wat groter lugvloei toelaat wat nodig is vir ontvlamming. Toepassing van hierdie kennis sal bydra tot die vermindering van die voorkoms van brande in graankorrel fasiliteite om sodoende die gevolge van verlies en omgewingsbesoedeling te vermy, en die gedrag van ander soortgelyke grane kan moontlik afgelei word. Daarbenewens kan die data gebruik word om berekeningsmodelle vir brandsimulasies te bekragtig of inbrandontwerp van sulke fasiliteite. Doctorate 2023-11-17T09:02:33Z 2024-02-20T07:00:34Z 2023-11-17T09:02:33Z 2024-02-20T07:00:34Z 2023-11 Thesis https://scholar.sun.ac.za/handle/10019.1/129308 en_ZA Stellenbosch University xii, 149 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Grain -- Processing -- Africa Fire ecology -- Africa Agricultural informatics -- Africa Flame spread -- Africa Food delivery services -- Africa Pyrolysis -- Africa Agriculture -- Safety measuresen -- Africa Temperature measuring instruments Thermogravimetry UCTD Oguaka, Anene Basil Chukwuzubelu Pyrolysis, ignition, and fire behaviour of agricultural food grains |
| title | Pyrolysis, ignition, and fire behaviour of agricultural food grains |
| title_full | Pyrolysis, ignition, and fire behaviour of agricultural food grains |
| title_fullStr | Pyrolysis, ignition, and fire behaviour of agricultural food grains |
| title_full_unstemmed | Pyrolysis, ignition, and fire behaviour of agricultural food grains |
| title_short | Pyrolysis, ignition, and fire behaviour of agricultural food grains |
| title_sort | pyrolysis ignition and fire behaviour of agricultural food grains |
| topic | Grain -- Processing -- Africa Fire ecology -- Africa Agricultural informatics -- Africa Flame spread -- Africa Food delivery services -- Africa Pyrolysis -- Africa Agriculture -- Safety measuresen -- Africa Temperature measuring instruments Thermogravimetry UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/129308 |
| work_keys_str_mv | AT oguakaanenebasilchukwuzubelu pyrolysisignitionandfirebehaviourofagriculturalfoodgrains |