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 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.

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 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 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 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.

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