scholarly journals Research on Ignition Energy Characteristics and Explosion Propagation Law of Coal Dust Cloud under Different Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Tianqi Liu ◽  
Ruiheng Jia ◽  
Ruicheng Sun ◽  
Weiye Tian ◽  
Ning Wang ◽  
...  
Keyword(s):  
Flame Propagation ◽  
Ignition Temperature ◽  
Coal Dust ◽  
Dust Cloud ◽  
Propagation Distance ◽  
Experimental Result ◽  
Ignition Energy ◽  
Minimum Ignition Energy ◽  
Energy Characteristics ◽  
Propagation Law

To study the ignition energy characteristics and explosion propagation law of coal dust cloud, a kind of coal dust cloud is studied through experiment and numerical simulation under different conditions. The result indicated that ignition delay time and dust spray pressure have obvious effects on the minimum ignition energy of coal dust cloud. CFD theory is used to simulate the explosion flame propagation. It is found that the simulation error of flame propagation distance is acceptable and the simulation result is consistent with the experimental result. When the spray pressure is 0.06 MPa, the flame propagation distance is the farthest, indicating that the turbulence of coal dust cloud is the largest at this condition. As the ignition temperature increases, the flame propagation distance continues to increase, proving that ignition temperature has an obvious effect on the flame propagation process of coal dust cloud explosion.

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.

The effects of coal dust concentrations and particle sizes on the minimum auto-ignition temperature of a coal dust cloud

2017 ◽  
Vol 41 (7) ◽  
pp. 908-915 ◽  
Author(s):  
Mohammed Jabbar Ajrash ◽  
Jafar Zanganeh ◽  
Behdad Moghtaderi
Keyword(s):  
Ignition Temperature ◽  
Coal Dust ◽  
Dust Cloud ◽  
Particle Sizes ◽  
Auto Ignition

scholarly journals Explosion Characteristics and Flame Propagation Behavior of Mixed Dust Cloud of Coal Dust and Oil Shale Dust

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3807 ◽  
Author(s):  
Junfeng Wang ◽  
Yansong Zhang ◽  
Huifeng Su ◽  
Jinshe Chen ◽  
Bo Liu ◽  
...  
Keyword(s):  
Gas Phase ◽  
Flame Propagation ◽  
Oil Shale ◽  
Coal Dust ◽  
Dust Cloud ◽  
Pressure Rise ◽  
Volatile Matter ◽  
Experimental Device ◽  
Dust Particles ◽  
Propagation Behavior

Coal and oil shale are often mined and utilized together, and mixed dust is easily formed in these processes. In order to ensure safe production in these processes, the explosion characteristics of mixed dust were studied. Using a Godbert-Greenwold (G-G) Furnace experimental device, Hartmann tube experimental device, and 20 L explosion vessel, the oil shale and coal mixed dust ignition sensitivity experiment, flame propagation experiment, and explosion characteristics experiment were carried out. The minimum ignition temperature (MIT), minimum ignition energy (MIE), maximum explosion pressure (Pmax), maximum rate of pressure rise ((dp/dt)max), and explosibility index (KSt) parameters and the flame propagation behavior of the mixed dust were analyzed in detail. A scanning electron microscope (SEM) analysis of the coal and oil shale dust before and after the explosion was carried out to study the changes in the microscopic morphology of the dust particles. The results show that due to the oil shale having a high volatile content and low moisture content, in the mixture, the greater the percentage of oil shale, the more likely the dust cloud is to be ignited and the faster the explosion flame is propagated; the greater the percentage of oil shale, the greater the (dP/dt)max and KSt will be and, under a high dust concentration, a greater Pmax will be produced. During explosion, coal dust will experience particle pyrolysis and the gas phase combustion of the volatile matter, followed by solid phase combustion of coal char, whereas oil shale dust will only experience particle pyrolysis and the gas phase combustion of the volatile matter.

scholarly journals Investigation of particle density on dust cloud dynamics in a minimum ignition energy apparatus using digital in-line holography

2021 ◽  
Vol 384 ◽  
pp. 297-303
Author(s):  
Shrey Prasad ◽  
Christian Schweizer ◽  
Pranav Bagaria ◽  
Ankit Saini ◽  
Waruna D. Kulatilaka ◽  
...  
Keyword(s):  
Particle Density ◽  
Dust Cloud ◽  
Ignition Energy ◽  
Minimum Ignition Energy ◽  
Cloud Dynamics
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