Rökpartiklars storleks beroende av syrehalt
(2022) In LUTVDG/TVBB VBRM01 20221Division of Fire Safety Engineering
- Abstract
- Particle size can be an important variable to know in many different areas, be it smoke simulations, toxicity of materials or tests of face masks. Fires in a reduced oxygen environment can occur for ventilation-controlled fires or in areas with artificially lowered oxygen levels. The effects of lower concentrations of oxygen on heat release rate, smoke production etc. has been studied, but any effect these changes in the combustion process has on the smoke particle size is not well known.
In this report three different materials are studied at different oxygen levels: polyetene (unexpanded plastic), polystyrene (expanded plastic) and cardboard. They are burned at 21, 19, 17 and 15 % oxygen and the smoke particle size is measured with a... (More) - Particle size can be an important variable to know in many different areas, be it smoke simulations, toxicity of materials or tests of face masks. Fires in a reduced oxygen environment can occur for ventilation-controlled fires or in areas with artificially lowered oxygen levels. The effects of lower concentrations of oxygen on heat release rate, smoke production etc. has been studied, but any effect these changes in the combustion process has on the smoke particle size is not well known.
In this report three different materials are studied at different oxygen levels: polyetene (unexpanded plastic), polystyrene (expanded plastic) and cardboard. They are burned at 21, 19, 17 and 15 % oxygen and the smoke particle size is measured with a DMS500 particulate analyzer. Three lasers of wavelength 735, 650 and 532 nm are also used to compare it as a possible future method of studying particle sizes.
The measurements with the DMS 500 showed that the particle diameters of polyetene decreased by approximately 4 nm per percent oxygen reduced from 21 from an initial size of around 200 nm, and polystyrene decreased by approximately 2-3 nm/percent oxygen from an initial size of around 240 nm. Cardboard showed a big switch around 19-17 % oxygen, where the combustion went from flaming to smouldering. During flaming combustion the particle diameters were around 20 nm, and during smouldering around 50-60 nm. All experiments also trended towards a secondary type of particle sizes during the end of tests, the particle size in every experiment ended around 20-30 nm in diameter.
Measurements with the lasers did not yield good values for the diameters for any of the tests. Variations in the lasers were tested in a basic sensitivty analysis and could be the reason for the poor results. A code was developed where other combinations of lasers can be tested in the future, when more lasers or a wider span of wavelengths might be able to yield more accurate results. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9104149
- author
- Wendt Höjer, Karl LU
- supervisor
- organization
- course
- VBRM01 20221
- year
- 2022
- type
- M2 - Bachelor Degree
- subject
- keywords
- Particle size – Hypoxic – CACC – Reducerad syrehalt – Cone calorimeter – Multi-wavelength light transmission measurements - Partikelstorlek
- publication/series
- LUTVDG/TVBB
- report number
- 5679
- other publication id
- LUTVDG/TVBB--5679--SE
- language
- Swedish
- id
- 9104149
- date added to LUP
- 2022-12-21 13:51:02
- date last changed
- 2022-12-21 13:51:02
@misc{9104149,
abstract = {{Particle size can be an important variable to know in many different areas, be it smoke simulations, toxicity of materials or tests of face masks. Fires in a reduced oxygen environment can occur for ventilation-controlled fires or in areas with artificially lowered oxygen levels. The effects of lower concentrations of oxygen on heat release rate, smoke production etc. has been studied, but any effect these changes in the combustion process has on the smoke particle size is not well known.
In this report three different materials are studied at different oxygen levels: polyetene (unexpanded plastic), polystyrene (expanded plastic) and cardboard. They are burned at 21, 19, 17 and 15 % oxygen and the smoke particle size is measured with a DMS500 particulate analyzer. Three lasers of wavelength 735, 650 and 532 nm are also used to compare it as a possible future method of studying particle sizes.
The measurements with the DMS 500 showed that the particle diameters of polyetene decreased by approximately 4 nm per percent oxygen reduced from 21 from an initial size of around 200 nm, and polystyrene decreased by approximately 2-3 nm/percent oxygen from an initial size of around 240 nm. Cardboard showed a big switch around 19-17 % oxygen, where the combustion went from flaming to smouldering. During flaming combustion the particle diameters were around 20 nm, and during smouldering around 50-60 nm. All experiments also trended towards a secondary type of particle sizes during the end of tests, the particle size in every experiment ended around 20-30 nm in diameter.
Measurements with the lasers did not yield good values for the diameters for any of the tests. Variations in the lasers were tested in a basic sensitivty analysis and could be the reason for the poor results. A code was developed where other combinations of lasers can be tested in the future, when more lasers or a wider span of wavelengths might be able to yield more accurate results.}},
author = {{Wendt Höjer, Karl}},
language = {{swe}},
note = {{Student Paper}},
series = {{LUTVDG/TVBB}},
title = {{Rökpartiklars storleks beroende av syrehalt}},
year = {{2022}},
}