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

2022 ◽  
Vol 12 (2) ◽  
pp. 548
Author(s):  
Eva Mračková ◽  
Jarmila Schmidtová ◽  
Iveta Marková ◽  
Jana Jaďuďová ◽  
Ivana Tureková ◽  
...  
Keyword(s):  
Picea Abies ◽  
Ignition Temperature ◽  
Ignition Time ◽  
Dust Particles ◽  
Size Analysis ◽  
Wood Dust ◽  
Physical Parameters ◽  
Dust Layer ◽  
Significant Dependence ◽  
Minimum Ignition Temperature

The issue of the formation of wood dust particles in the work environment is still an actual topic in terms of its impact on employee health and the risk of fire or explosion in a woodworking operation. This article deals with the characteristics of spruce dust (Picea abies Karst. (L.)), which was taken from several types of wood technology. Experimental samples of spruce dust were taken from four types of sawing technologies, including grinding, briquetting and from the suction device container. The physical parameters of the samples taken were monitored and the particle size analysis was determined. The granulometric composition of the samples is significantly different. The sample of spruce wood dust from sawing has the most numerous fraction (250 µm), while the sample from grinding has the most numerous fraction 63–250 µm (87%).The aim of the paper was to monitor the minimum ignition temperature of the settled spruce dust layer and to look for a significant dependence of the minimum ignition temperature and ignition time on the type of spruce dust sample. A significant dependence was not confirmed. Significant moisture dependence of the samples was confirmed; the highest humidity was observed in the container, the lowest in sawing.

scholarly journals Ignition of Deposited Wood Dust Layer by Selected Sources

2020 ◽  
Vol 10 (17) ◽  
pp. 5779 ◽  
Author(s):  
Ivana Tureková ◽  
Iveta Marková
Keyword(s):  
Ignition Temperature ◽  
Ignition Time ◽  
Dust Sample ◽  
Spatial Arrangement ◽  
Quercus Petraea ◽  
Ignition Source ◽  
Dust Particles ◽  
Wood Dust ◽  
Sieve Analysis ◽  
Ignition Process

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.

scholarly journals Minimum Ignition Temperature of Wood Dust Layers

2013 ◽  
Vol 21 (Special-Issue) ◽  
pp. 127-131
Author(s):  
Martin Pastier ◽  
Ivana Tureková ◽  
Zuzana Turňová ◽  
Jozef Harangozó
Keyword(s):  
Ignition Temperature ◽  
Standardized Test ◽  
Fire Risk ◽  
Test Methods ◽  
Technical Characteristic ◽  
Laboratory Method ◽  
Wood Dust ◽  
Explosion Hazard ◽  
Dust Layer ◽  
Minimum Ignition Temperature

Abstract Fire characteristic (properties) are used to determine the fire risk and explosion hazard of materials. They are defined as numerical values which describe behavior in the process of burning. They can be determinate by standardized test methods. In this paper is described the most important fire technical characteristic of dust layer (minimum ignition temperature) and the results of standard laboratory method determination for wood dusts, aswell.

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

2021 ◽  
Vol 11 (15) ◽  
pp. 6874
Author(s):  
Miroslava Vandličkova ◽  
Iveta Markova ◽  
Katarina Holla ◽  
Stanislava Gašpercová
Keyword(s):  
Particle Size ◽  
Dust Particles ◽  
Wood Dust ◽  
Sieve Analysis ◽  
Granulometric Analysis ◽  
Analysis Measurement ◽  
Risk Research ◽  
Minimum Ignition Temperature ◽  
The Impact

The paper deals with the selected characteristics, such as moisture, average bulk density, and fraction size, of tropical marblewood dust (Marmaroxylon racemosum) that influence its ignition risk. Research was focused on sieve analysis, granulometric analysis, measurement of moisture level in the dust, and determination of the minimum ignition temperatures of airborne tropical dust and dust layers. Samples were prepared using a Makita 9556CR 1400W grinder and K36 sandpaper for the purpose of selecting the percentages of the various fractions (<63, 63, 71, 100, 200, 315, 500 μm). The samples were sized on an automatic vibratory sieve machine Retsch AS 200. More than 65% of the particles were determined to be under 100 μm. The focus was on microfractions of tropical wood dust (particles with a diameter of ≤100 µm) and on the impact assessment of particle size (particle size <100 µm) on the minimum ignition temperatures of airborne tropical dust and dust layers. The minimum ignition temperature of airborne marblewood dust decreased with the particle size to the level of 400 °C (particle size 63 μm).

scholarly journals Variation of ignition sensitivity characteristics of non-stick coal dust explosions

2020 ◽  
Author(s):  
Di Sha ◽  
Yucheng Li ◽  
Xihua Zhou ◽  
Ruiqing Li
Keyword(s):  
Ignition Temperature ◽  
Coal Dust ◽  
Dust Cloud ◽  
Particle Sizes ◽  
Ignition Energy ◽  
Minimum Ignition Energy ◽  
Dust Layer ◽  
Independent Variables ◽  
Minimum Ignition Temperature ◽  
Dust Explosions

Abstract The ignition and explosion of coal dust are significant hazards in coal mines. In this study, the minimum ignition temperature and energy of non-stick coal dust were investigated empirically at different working conditions to identify the key factors that influence the sensitivity and characteristics of coal dust explosions. The results showed that for a given particle size, the minimum ignition temperature of the coal dust layer was inversely related to the thickness of the coal dust layer. Meanwhile, when the layer thickness was kept constant, the minimum ignition temperature of the coal dust layer decreased with smaller coal dust particle sizes. Over the range of particle sizes tested (25–75 μm), the minimum ignition temperature of the coal dust cloud gradually increased when larger particles was used. At the same particle size, the minimum ignition temperature of the coal dust layer was much lower than that of the coal dust cloud. Furthermore, the curves of minimum ignition energy all exhibited a minimum value in response to changes to single independent variables of mass concentration, ignition delay time and powder injection pressure. The interactions of these three independent variables were also examined, and the experimental results were fitted to establish a mathematical model of the minimum ignition energy of coal dust. Empirical verification demonstrated the accuracy and practicability of the model. The results of this research can provide an experimental and theoretical basis for preventing dust explosions in coal mines to enhance the safety of production.

scholarly journals Analysis of minimum ignition temperature of pellet dust layer and cloud due to adding BC and ABC fire extinguishing powders

2018 ◽  
Vol 247 ◽  
pp. 00003
Author(s):  
Bożena Kukfisz
Keyword(s):  
Outer Surface ◽  
Ignition Temperature ◽  
Test Results ◽  
Dust Layer ◽  
Fire Extinguishing ◽  
Minimum Ignition Temperature ◽  
The Impact

The paper describes the impact of adding fire extinguishing powders acting based on oxygen or flame on values of minimum ignition temperatures of the layer and cloud of pellet dust, and as a consequence the impact or lack of impact on values of maximum admissible temperature on external surfaces of electrical appliances working in their atmospheres. Tests were conducted of the minimum ignition temperature of layer and cloud of the agro armakow pellet dust and the agro jesień pellet dust, with and without additives of fire extinguishing powders BC Jet, BC LB2, ABC 90 and Ogniotex 103 at concentrations ranging from 5 to 70% by weight of powder contents in the mixture. Based on obtained test results it has been ascertained that type ABC powders appear to be much more effective than those type BC, because they have a much bigger impact on increasing the minimum ignition temperature of the layer and the cloud of analysed dust types. Adding only 15% of ABC 90 extinguishing powder to the agro jesień pellet has caused an increase in the minimum ignition temperature of dust layer by 80°C. The BC LB2 powder with agro armakow pellet dust has not been found to cause any changes, even at its concentration as high as 70%. The most optimum additive of powder to the biomass dust was 10% by weight of ABC powder in the mixture. At this concentration the highest increase was recorded in the maximum admissible temperature on the outer surface of electrical appliances from 235°C to 273°C.

scholarly journals Experimental Study Of Minimum Ignition Temperature Of Spent Coffee Grounds

2015 ◽  
Vol 10 (2) ◽  
pp. 1-7
Author(s):  
Igor Wachter ◽  
Karol Balog ◽  
Hana Kobetičová ◽  
Aleš Ház
Keyword(s):  
Ignition Temperature ◽  
Dust Cloud ◽  
Scientific Paper ◽  
Spent Coffee Grounds ◽  
Hot Plate ◽  
Dust Layer ◽  
Dust Clouds ◽  
Coffee Grounds ◽  
High Layer ◽  
Minimum Ignition Temperature

Abstract The aim of this scientific paper is an analysis of the minimum ignition temperature of dust layer and the minimum ignition temperatures of dust clouds. It could be used to identify the threats in industrial production and civil engineering, on which a layer of combustible dust could occure. Research was performed on spent coffee grounds. Tests were performed according to EN 50281-2-1:2002 Methods for determining the minimum ignition temperatures of dust (Method A). Objective of method A is to determine the minimum temperature at which ignition or decomposition of dust occurs during thermal straining on a hot plate at a constant temperature. The highest minimum smouldering and carbonating temperature of spent coffee grounds for 5 mm high layer was determined at the interval from 280 °C to 310 °C during 600 seconds. Method B is used to determine the minimum ignition temperature of a dust cloud. Minimum ignition temperature of studied dust was determined to 470 °C (air pressure - 50 kPa, sample weight 0.3 g).

scholarly journals Study of Fire Characteristics of Industrial Dust

2019 ◽  
Vol 27 (44) ◽  
pp. 49-56
Author(s):  
Zuzana Szabová ◽  
Richard Kuracina
Keyword(s):  
Particle Size ◽  
Ignition Temperature ◽  
Dust Layer ◽  
Industrial Dust ◽  
Explosion Limit ◽  
Minimum Ignition Temperature ◽  
Fire Characteristics ◽  
Hot Surface

Abstract The article deals with the determination of fire characteristics of industrial dust samples. Particle size granulometry and determination of explosion parameters according to EN 14034 (Lower Explosion Limit LEL, Pmax, Kst) are presented. The minimum ignition temperatures of the dust layer and dispersed dust from the hot surface according to EN ISO / IEC 80079-20-2: 2016 were measured. It was found that LEL is 60 g.m−3, Pmax is 8.61 bar, and Kst is 89 bar.s−1.m. The minimum ignition temperature (MIT) of dust layer is 280 ° C and the minimum ignition temperature of dispersed dust is 400 ° C.

scholarly journals Tropical Wood Dusts—Granulometry, Morfology and Ignition Temperature

2020 ◽  
Vol 10 (21) ◽  
pp. 7608
Author(s):  
Miroslava Vandličková ◽  
Iveta Marková ◽  
Linda Makovická Osvaldová ◽  
Stanislava Gašpercová ◽  
Jozef Svetlík ◽  
...  
Keyword(s):  
Ignition Temperature ◽  
Dust Particles ◽  
Wood Dust ◽  
Particle Sizes ◽  
Explosive Mixture ◽  
Tropical Wood ◽  
Granulometric Analysis ◽  
Tropical Woods ◽  
Automatic Mesh ◽  
Dipteryx Odorata

The article considers the granulometric analysis of selected samples of tropical wood dust from cumaru (Dipteryx odorata), padauk (Pterocarpus soyauxii), ebony (Diospyros crassiflora), and marblewood (Marmaroxylon racemosum) using a Makita 9556CR 1400 W grinder and K36 sandpaper, for the purpose of selecting the percentages of the various fractions (<63; 63; 71; 200; 315; 500 μm) of wood dust samples. Tropical wood dust samples were made using a hand orbital sander Makita 9556CR 1400 W, and sized using the automatic mesh vibratory sieve machine Retsch AS 200 control. Most dust particles (between 50–79%) from all wood samples were under 100 μm in size. This higher percentage is associated with the risk of inhaling the dust, causing damage to the respiratory system, and the risk of a dust-air explosive mixture. Results of granulometric fractions contribution of tropical woods sanding dust were similar. Ignition temperature was changed by particle sizes, and decreased with a decrease in particle sizes. We found that marblewood has the highest minimum ignition temperature (400–420 °C), and padauk has the lowest (370–390 °C).

Determination of Ignition Temperature of Organic Dust Layers

2013 ◽  
Vol 690-693 ◽  
pp. 1469-1472 ◽  
Author(s):  
Ivana Turekova ◽  
Zuzana Turňová ◽  
Jozef Harangozó ◽  
Ivana Kasalova ◽  
Tomáš Chrebet
Keyword(s):  
Ignition Temperature ◽  
Organic Dust ◽  
Qualitative Comparison ◽  
Dust Layer ◽  
Different Types ◽  
Minimum Ignition Temperature ◽  
Precautionary Measures ◽  
Fire Characteristics

Fire characteristics of wood dusts serve for qualitative comparison of combustibility and explosibility, for suggesting precautionary measures, for predicting consequences of fires and explosions. Setting of given characteristics by calculation is not possible yet. Therefore the most reliable results are set by experiment. The article deals with the testing of the minimum ignition temperature depending on the different types of dust layer and different heights of surface.

Study on Ignition Time of Radiation Cargo in Irradiation Room under Stuck Radioactive Sources

2014 ◽  
Vol 580-583 ◽  
pp. 2607-2611
Author(s):  
Xiao Lin Yao
Keyword(s):  
Temperature Field ◽  
Temperature Variation ◽  
Ignition Temperature ◽  
Ignition Time ◽  
Radioactive Source ◽  
Fire Scenario ◽  
Minimum Ignition Temperature ◽  
Radioactive Sources

Ignition temperatures of common radiation cargo in irradiation room were measured through the experiments, minimum ignition temperature is 210 °C. In order to discuss the temperature variation and temperature field under stuck radioactive sources, the fire scenario was presented and simulated by FDS. The results show that temperatures rise rapidly when stuck radioactive source broke out within an hour. As the growth of the time, temperatures in irradiation room are rising, but the rising rate is slowing. The temperature field in the irradiation room tends to be the same after three hours. The stuck radioactive source occurred after 2.4 days later, local temperatures can reach 210 °C, and radiation cargo may be ignited.

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