The Effect of Char Oxidation on the Flaming Combustion Characteristics of Wood Materials (original) (raw)
Related papers
Ignition of wood-based materials by thermal radiation
International Journal on Engineering Performance-Based Fire Codes, 2006
Ignition is the initial stage of burning the materials. Consequent flame spread over the materials, heat release rate, fire spread across the rooms, and other issues for building fires all depend on that. Ignition of cellulose materials is commonly classified as smoldering or glowing ignition (self-heating ignition) and flaming ignition including piloted and spontaneous ignition. Numerous studies on this topic were reported in the literature. A review on ignition of wood will be reported in this paper. Ignition temperature, critical mass flux of volatiles, time to ignition, critical heat flux and critical heat release were measured experimentally and applied as key ignition criteria for theoretical analysis. Quantitative study on modeling smoldering ignition of cellulosic materials is not yet well understood. As experimental data is inadequate, this part is only briefly discussed. Models of flaming ignition were well developed from those well validating experimental data. However, most of the flaming ignition models of wood were only on the solid phase. Gas phase phenomena during ignition should be further examined for developing flaming ignition models.
Effective heat of combustion for flaming combustion of conifers
Canadian Journal of Forest Research, 2006
The heat of combustion of burning trees is often used in forest-fire hazard modeling to relate mass-loss results to the heat produced; therefore reliable values are needed. Experimental results for the effective heat of combustion of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees are presented as a function of moisture content. It is also shown that during a forest fire, the effective heat of combustion does not correspond to the oxygen-bomb-test value. Instead, the value will always be lower, since the heat of combustion of char is higher than that of the pyrolysate vapors, and char mostly remains unburned during a forest fire. These are the first and only experimental results obtained from testing of actual trees. But results from benchmark testing and studies on wood products by other investigators are broadly consistent with our findings. It is further shown that moisture content has a major effect on the effective heat of combustion. A quantitative expression for the ...
International Journal on Engineering Performance-Based Fire Codes, 2005
Fire behaviour of timber partition materials were assessed in a room calorimeter with size following ISO 9705. Fourteen full-scale burning tests on timber materials used in the local industry with and without paint, wallpaper, fiberglass and fire retardant were carried out. The heat release rate, surface temperature of materials, upper layer gas temperature, floor heat flux and time to flashover were recorded. Flame spreading over the materials was observed. Results are useful for comparing the flame spreading behaviour of different surfacing and insulating materials with and without fire retardants. It is observed that materials with rapid flame spreading rate might not necessarily give a shorter time to flashover. The performance of fire retardant depends on the substrate and the orientation of the materials.
Assessment of fire behaviour of timber partition materials with a room calorimeter
International Journal on Engineering Performance-Based Fire Codes, 2007
Fire behaviour of timber partition materials were assessed in a room calorimeter with size following ISO 9705. Fourteen full-scale burning tests on timber materials used in the local industry with and without paint, wallpaper, fiberglass and fire retardant were carried out. The heat release rate, surface temperature of materials, upper layer gas temperature, floor heat flux and time to flashover were recorded. Flame spreading over the materials was observed. Results are useful for comparing the flame spreading behaviour of different surfacing and insulating material with and without fire retardants. It is observed that materials with rapid flame spreading rate might not necessarily give a shorter time to flashover. The performance of fire retardant depends on the substrate and the orientation of the materials.
Combustion Properties of Several Species of Wood
Chemistry & Chemical Technology, 2009
Six species of wood were studied by combined thermogravimetric and differential thermal analysis (TG/DTA) so as to evaluate their combustion properties in terms of the amount of energy released, the initial temperature of ignition, and the cleanness of burning. Pinus monticola, Acer saccharum, Quercus rubra, Diospyrus spp., Tabebuia spp. and Guaiacum spp. were chosen to provide a wide range of hardness values and densities. Quercus rubra burned to the hottest temperature of the samples, and also left the least amount of ash behind. For Guaiacum spp. its burning temperature is in the middle of the peak temperatures for other woods – while its final amount of ash is considerably larger than in the other samples. There is no connection between the wood density and the parameters characterizing the burning process.
A review on ignition of cellulose materials under external heat flux
International Journal on Engineering Performance-Based Fire Codes, 2006
Ignition is the initial stage of burning the materials. The consequent flame spread over the materials, heat release rate, fire spread across the rooms, and other issues for building fires all depend on that. Numerous studies on the ignition of cellulose materials, especially wood, were reported in the literature. There are smoldering or glowing ignition (self-heating ignition) and flaming ignition including piloted and spontaneous ignition. A review of the literature on flaming ignition will be reported in this paper. The ignition temperature, critical mass flux of volatiles, time to ignition, critical heat flux and critical heat release were measured experimentally and applied as key ignition criteria for theoretical analysis. Models of flaming ignition are well-developed from those well-validated experimental data. However, most of the flaming ignition models of wood are only on the solid phase. New theory on gas phases should be developed for further studying flaming ignition, especially the spontaneous ignition of wood. Quantitative study on modeling smoldering ignition of cellulosic materials is not yet well understood as experimental data are inadequate. This part is only briefly discussed.