Ignition of Deposited Wood Dust Layer by Selected Sources

Abstract

The main waste of wood sanding technology is wood dust. The formation of wood dust affects its behaviour. Wood dust can be in a turbulent form and behaves explosively or in a settled form where it becomes flammable. Dust particles are barely detectable by the naked eye, wood dust still presents substantial health, safety, fire and explosion risks to employees. This article deals with the evaluation of ignition temperature and surface temperature of deposited wood dust samples by selected ignition sources. The influence of selected physical properties of wood dust, the size of the contact area between the ignition source and the combustible material, the spatial arrangement during the ignition and the application time of the ignition source are analysed. The paper describes the behaviour of a 15 mm deposited layer of wood dust of spruce (Picea abies L.), beech (Fagus silvatica L.). oak (Quercus petraea Liebl.) caused by three potential ignition sources—a hot surface, an electric coil and a smouldering cigarette. Prior to the experimental determination of the ignition temperature, dust moisture content which did not significantly affect the ignition phase of the samples, as well as sieve analysis of tested samples were determined. The lowest minimum ignition temperature on the hot plate, as an important property of any fuel, because the combustion reaction of the fuel becomes self-sustaining only above this temperature, was reached by the oak dust sample (280 °C), the highest by the spruce dust sample (300 °C). The ignition process of wood dust was comparable in all samples, differing in the ignition time and the area of the thermally degraded layer. The least effective ignition source was a smouldering cigarette.

Evaluation of Marblewood Dust’s (Marmaroxylon racemosum) Effect on Ignition Risk

“…The experiments were performed on a laboratory hot plate apparatus with temperature controller, type CLARE 4.0, with measurement errors of ±0.3 • C (Clasic, Czech Republic) in the experimental laboratory at the Faculty of Safety Engineering in Žilina (Slovakia). Detailed information about the behavior test is available in [38,39].…”

Fire Parameters of Spruce (Picea abies Karst. (L.)) Dust Layer from Different Wood Technologies Slovak Case Study

“…The ignition of a layer of dust on a surface at a given temperature depended significantly on the balance between the rate of heat generation (self-heating) in the layer and the rate of heat transfer to the surroundings. The ignition temperature of the material depended on the thickness of the layer [53]. According to EN 50281-2-1: 2002 [52], ignition is considered to be the case if:…”

“…Tureková and Marková [53] carried out a hot-plate experiment with samples of spruce, beech and oak dusts. The samples (sawdust) were produced using a circular saw.…”

Determination of flammability parameters for organic waste resulting from the processing of sunflower seeds

“…The energies required to ignite mixtures within the explosion range are much higher than the minimum ignition energy determined at the stoichiometric concentration. [9,10] Minimum ignition energy is a particularly important parameter for safety standards but also for understanding the process of initiating explosive mixtures. The minimum ignition energies for most gaseous hydrocarbons are very small (0.2 -0.3 mJ).…”