Hazards of Explosibility Dust from Wood Pellets

2014 ◽  
Vol 1001 ◽  
pp. 324-329
Author(s):  
Jozef Horváth ◽  
Karol Balog ◽  
Domenico Scarafilo
Keyword(s):  
Ignition Temperature ◽  
Dust Cloud ◽  
Dust Particles ◽  
Wood Pellets ◽  
Experimental Part ◽  
Dangerous Situation ◽  
Fire And Explosion ◽  
Fire And Explosion Hazards ◽  
Minimum Ignition Temperature

The main purpose of this publication is to determine minimal ignition temperature of dust cloud. The flammable and explosive dust is formed during the production, transport, storage and usage of the wood pallets. The examined samples in experimental part of the work were made from different kind of pallets. Contribution deals with analysis of fire and explosion hazards of dust particles generated during transportation and handling of wood pellets. Minimum ignition temperature of dust cloud were performed according to STN EN 50281-2-1. In terms of forensic approach, by using of selected methods, the conditions in which initiation and explosion of dust can be occurred were simulated the exposibility for wood pellets dust was tested under different condition using various pressures and various weight to samples. Defining the conditions in which the risk of formation of dangerous situation exists, helps to predict the fire and explosion in the premises where the pellets are used.

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 Fire and Explosion Hazards Due to Medical Oxygen Handling During Coronavirus Pandemic

2021 ◽  
pp. 1-4
Author(s):  
Wedad H. Al Dahhan ◽  
Wedad H. Al Dahhan ◽  
Emad Yousif
Keyword(s):  
Oxidation Products ◽  
Inert Gases ◽  
Confined Space ◽  
Oil And Grease ◽  
Atmospheric Air ◽  
Dangerous Situation ◽  
Fire And Explosion ◽  
Fire And Explosion Hazards ◽  
Dangerous Level ◽  
Take All

With the continued outbreak of the coronavirus and the increase in the need for medical oxygen, it became necessary to take all measures for the safe handling of gas. Oxygen is very reactive and behaves differently to air, compressed air, nitrogen and other inert gases. Medical oxygen, at high pressure, from a cylinder, can react violently with hydrocarbons such as oil and grease which may be used mistakenly in cylinder valve or regulator. The oxidation products are a potentially explosive hydroperoxide. Nearly all materials including rubber, textiles, and metals will burn vigorously in the presence of oxygen. Atmospheric air contains nitrogen 78%, oxygen about 21% and with 1% remaining including a variety of other gases like carbon dioxide and argon. Even a small increase in the oxygen level in the air to about 24% can create a dangerous situation. It becomes easier to start a fire, which will then burn hotter and more fiercely than in atmospheric air and may be impossible to put the fire out. Increase the concentration of oxygen due to leaking valve or hose in a poorly ventilated room or in confined space can quickly create a dangerous level.

Experimental Analysis of Minimum Ignition Temperature of Dust Cloud Obtained from Thermally Modified Spruce Wood

2014 ◽  
Vol 919-921 ◽  
pp. 2057-2060
Author(s):  
Jaroslav Zigo ◽  
Peter Rantuch ◽  
Karol Balog
Keyword(s):  
Ignition Temperature ◽  
Dust Cloud ◽  
Pressure Rise ◽  
Dust Sample ◽  
Air Pressure ◽  
Sample Weight ◽  
Dust Clouds ◽  
Spruce Wood ◽  
Minimum Ignition Temperature

This article deals with study of minimum ignition temperature (MIT) of thermally modified spruce dust. Dust of several species of spruce was mixed, sieved, dried and subjected to Thermo-S temperature programme. Samples of dust (200 250 μm) were tested in Goldbert-Greenwald furnace apparatus for determination of the MIT of dust clouds. The influence of air pressure and sample weight to the MIT was studied. The results show that the MIT of thermally modified spruce dust gradually decreases as the sample weight and air pressure rise. The lowest value of MIT (470 °C) was measured, when the air pressure was 50 kPa and the sample weight 0,5 g. To reach even lower values of MIT (˂468 °C), the air pressure should gradually rise to approx. 42 46 kPa and the weight of dust sample should be approx. 0,46 0,53 g.

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 Pyrophoric sulfides influence over the minimum ignition temperature of dust cloud

2017 ◽  
Author(s):  
Maria Prodan ◽  
Leonard Andrei Lupu ◽  
Emilian Ghicioi ◽  
Irina Nalboc ◽  
Andrei Szollosi-Mota
Keyword(s):  
Ignition Temperature ◽  
Dust Cloud ◽  
Minimum Ignition Temperature

scholarly journals Analysis of susceptibility of inflammable tobacco products dust to ignition from a heated surface

2018 ◽  
Vol 247 ◽  
pp. 00005
Author(s):  
Marzena Półka
Keyword(s):  
Ignition Temperature ◽  
Heated Surface ◽  
Dust Cloud ◽  
Tobacco Product ◽  
Explosion Hazard ◽  
Structural Elements ◽  
Tobacco Products ◽  
Dust Layer ◽  
Safety Requirements ◽  
Fire And Explosion

In the article was described combustible properties of tobacco product dust. Those properties decide about fire and explosion hazard for dust in layer and in cloud according to PN-EN 50281-2-1:2002 and PN-EN ISO/IEC 80079-20-2. There were determined protection against fire and explosion requirements of buildings structural elements and appliances used in space where dust accumulates. The article also consists safety requirements of using appliances in explosion hazard areas according to PN-EN 60079-14:2014. In the article are presented results of minimal ignition temperature of layer (MITL) and minimal ignition temperature of cloud dust (MTCD) as a function of dust layer thickness of chosen tobacco product and values of maximum acceptable surface temperature (MAST) of machines operating in the presence of dust cloud and chosen dust layer with thickness of 5 and 12.5mm.

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.

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