Indonesia Coal Explosive Characteristic of Pulverized Coal in Experiment

2011 ◽  
Vol 418-420 ◽  
pp. 706-711
Author(s):  
Jia Hu Li ◽  
Li Bao Yin
Keyword(s):  
Pulverized Coal ◽  
Maximum Pressure ◽  
Explosion Pressure ◽  
Maximum Explosion Pressure

In this paper, the explosion experiments of Indonesia pulverized coal cloud are carried out. The pressure histories are recorded. The maximum pressure, the maximum pressure rising rates and the explosion time are analysed based on the pressure histories. The experiment results indicate that with the increase of pulverized coal concentration, the maximum explosion pressure and maximum pressure rising rate at first increases, then decreases, and the explosion time is contrary to that.

Experimental Study of Explosion Pressure Characteristics of Methane under High Temperature Conditions

2014 ◽  
Vol 687-691 ◽  
pp. 148-152 ◽  
Author(s):  
Run Zhi Li ◽  
Rong Jun Si ◽  
Yan Song Zhang
Keyword(s):  
Environmental Temperature ◽  
Pressure Rise ◽  
Test System ◽  
Coal Bed ◽  
Maximum Pressure ◽  
Explosion Pressure ◽  
Pressure Rise Rate ◽  
Maximum Explosion Pressure ◽  
Rise Rate ◽  
Pressure Characteristics

Methane explosion pressure characteristics under the condition of different temperatures (25°C-200 °C) were studied by the special environment 20L explosion characteristics test system. By the experimental results, in the case of other conditions unchanged, with the increase of environmental temperature, the maximum explosion pressure of the optimum explosion concentration decrease, the maximum explosion pressure and the reciprocal of environmental temperature show linear attenuation law, the maximum pressure rise rate is not influenced by environmental temperature basically; Outside the scope of explosion limits at normal temperature and pressure, with the increase of environmental temperature, no explosion methane-air mixture are explosive gradually, the maximum explosion pressure and maximum pressure rise rate are in the relationship of different exponential growth with the increase of ambient temperature. The conclusions provide an important theoretical basis for prevent mine gas explosion accidents and coal bed methane safely use.

scholarly journals Temperature effect on explosion parameters of hydrogen-air deflagrations in presence of water vapor

2016 ◽  
Vol 7 (3) ◽  
pp. 39-44
Author(s):  
Marcin Grabarczyk ◽  
Mateusz Żbikowski ◽  
Łukasz Mężyk ◽  
Andrzej Teodorczyk
Keyword(s):  
Water Vapor ◽  
Initial Temperature ◽  
Volume Fraction ◽  
Initial Conditions ◽  
Initial Pressure ◽  
High Water ◽  
Maximum Pressure ◽  
Explosion Pressure ◽  
Maximum Explosion Pressure ◽  
And Shifts

Results of investigation of hydrogen-air deflagrations phenomenon in closed vessel in various initial temperatures and volume fraction of water vapor are presented in following paper. Tests were performed in apparatus which construction complies with EN 15967 recommendations—20-litre sphere. Studied parameters were explosion pressure (Pex) and maximum explosion pressure (Pmax). Defining the influence of the initial conditions (temperature and amount of water vapor) on the maximum pressure of the hydrogen-air deflagration in a constant volume was the main aim. Initial temperatures were equal to 373K, 398K and 413K. Initial pressure was ambient (0.1 MPa). Hydrogen volume fraction differed from 15% to 80%, while humidity volume fraction from 0% to 20%. Ignition source was placed in geometrical center of testing chamber and provided energy between 10-20J from burnout of fuse wire with accordance to abovementioned standard. Common features of all experimentally obtained results were discussed. Maximum explosion pressure (Pmax) decreases with increasing the initial temperature. Furthermore, addition of the water vapor for constant initial temperature decreases value of Pmax and shifts the maximum peak to the direction of lean mixtures. Data provided in paper can be useful in assessment of explosion risk of industry installations working with hydrogen-air atmospheres with high water vapor addition.

scholarly journals The dissociation of carbon dioxide at high temperatures

1927 ◽  
Vol 115 (771) ◽  
pp. 318-333 ◽  
Keyword(s):  
Carbon Dioxide ◽  
High Temperatures ◽  
Combustion Engine ◽  
Initial Pressure ◽  
Simple Relation ◽  
Maximum Temperature ◽  
Maximum Pressure ◽  
Complete Combustion ◽  
Explosion Pressure ◽  
Rich Mixture

The power of an internal combustion engine is greatest when operating with a “rich” mixture, that is to say, with a mixture which contains more fuel than is necessary for complete combustion. Similarly, it is found that if mixtures of carbon monoxide and air in varying proportions are exploded in a closed bomb at constant initial temperature and pressure, the explosion pressure is greatest when the ratio CO/O 2 is greater than 2. These phenomena are known to be connected with the dissociation of carbon dioxide at high temperatures, for if there were no dissociation we should expect the explosion pressure to be greatest when CO/O 2 = 2. No attention appears, however, to have been paid to the position of the maximum. It can be shown in the following way that there is a very simple relation between the composition of the mixture giving maximum pressure on explosion, and the dissociation of carbon dioxide at the maximum explosion temperature. Let the initial composition be represented by the expression 2 (1 + a ) CO + O 2 + b N 2 (Total mols = 3 + 2 a + b ), and let P i , T i represent the initial pressure and temperature; P e the maximum pressure observed after explosion, and T e the corresponding maximum temperature.

scholarly journals Numerical Simulation of Magnesium Dust Dispersion and Explosion in 20 L Apparatus via an Euler–Lagrange Method

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 402
Author(s):  
Tao Fu ◽  
Yun-Ting Tsai ◽  
Qiang Zhou
Keyword(s):  
Ignition Time ◽  
Particle Dispersion ◽  
Maximum Pressure ◽  
Lagrange Method ◽  
Explosion Pressure ◽  
Experimental Apparatus ◽  
Pressure Development ◽  
Fluid Properties ◽  
Field Velocity ◽  
Dust Dispersion

Computational fluid dynamics (CFD) was used to investigate the explosion characteristics of a Mg/air mixture in a 20 L apparatus via an Euler–Lagrange method. Various fluid properties, namely pressure field, velocity field, turbulence intensity, and the degree of particle dispersion, were obtained and analyzed. The simulation results suggested that the best delayed ignition time was 60 ms after dust dispersion, which was consistent with the optimum delayed ignition time adopted by experimental apparatus. These results indicate that the simulated Mg particles were evenly diffused in the 20 L apparatus under the effect of the turbulence. The simulations also reveal that the pressure development in the explosion system can be divided into the pressure rising stage, the maximum pressure stage, and pressure attenuation stage. The relative error of the maximum explosion pressure between the simulation and the experiments is approximately 1.04%. The explosion model provides reliable and useful information for investigating Mg explosions.

scholarly journals Determination of the Explosion Characteristics of Wheat Flour

2017 ◽  
Vol 25 (40) ◽  
pp. 9-16
Author(s):  
Richard Kuracina ◽  
Zuzana Szabová ◽  
Denisa Pangrácová ◽  
Karol Balog
Keyword(s):  
Wheat Flour ◽  
Maximum Rate ◽  
Pressure Rise ◽  
Explosion Pressure ◽  
Maximum Explosion Pressure ◽  
Dust Clouds ◽  
Maximum Value ◽  
Flour Dust ◽  
Explosion Limit

Abstract The article deals with the measurement of explosion characteristics of wheat flour. The measurements were carried out according to STN EN 14034-1+A1:2011 Determination of explosion characteristics of dust clouds. Part 1: Determination of the maximum explosion pressure pmax of dust clouds, the maximum rate of explosion pressure rise according to STN EN 14034-2+A1:2012 Determination of explosion characteristics of dust clouds - Part 2: Determination of the maximum rate of explosion pressure rise (dp/dt)max of dust clouds and LEL according to STN EN 14034-3+A1:2011 Determination of explosion characteristics of dust clouds: Determination of the lower explosion limit LEL of dust clouds. The testing of explosions of wheat flour dust clouds showed that the maximum value of the pressure was reached at the concentrations of 600 g/m3 and its value is 8.32 bar/s. The fastest increase of pressure was observed at the concentration of 750 g/m3 and its value was 54.2 bar/s.

scholarly journals Variation and Prediction Methods of the Explosion Characteristic Parameters of Coal Dust/Gas Mixtures

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 264
Author(s):  
Yingquan Qi ◽  
Xiangyang Gan ◽  
Zhong Li ◽  
Lu Li ◽  
Yan Wang ◽  
...  
Keyword(s):  
Coal Dust ◽  
Dust Cloud ◽  
Prediction Method ◽  
Gas Mixtures ◽  
Gas Mixture ◽  
Characteristic Parameters ◽  
Explosion Pressure ◽  
Maximum Explosion Pressure ◽  
Spherical Explosion ◽  
Explosion Limit

In order to investigate the change law of the explosion characteristic parameters of hybrid mixture of coal dust and gas, and then establish an effective prediction method of these parameters, the maximum explosion pressure, explosion index, and lower explosion limit of coal dust and gas mixtures were measured in a standard 20 L spherical explosion system. Four different kinds of hybrid mixture were selected in this study and they are composed of coal dust with different components and gas respectively. According to the measured results, the change law of the explosion characteristic parameters of hybrid mixture of coal dust and gas was analyzed, and the prediction method of these parameters was discussed. The results show that the addition of gas to a coal dust cloud can obviously increase its maximum explosion pressure and explosion index and notably reduce its minimum explosion concentration. On increasing the gas equivalent ratio, the maximum explosion pressure of coal dust and gas mixture increases linearly and the explosion index increases quadratically, while the decrease curve of the lower explosion limit is nonlinear. Based on these change laws, the methods for predicting the maximum explosion pressure and the explosion index of hybrid mixture of coal dust and gas were established respectively. The applicability of the existing methods for predicting the lower explosion limit of hybrid mixture to coal dust and gas mixture was demonstrated.

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