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The effects of coal dust concentrations and particle sizes on the minimum auto‐ignition temperature of a coal dust cloud
Author(s) -
Ajrash Mohammed Jabbar,
Zanganeh Jafar,
Moghtaderi Behdad
Publication year - 2017
Publication title -
fire and materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.482
H-Index - 58
eISSN - 1099-1018
pISSN - 0308-0501
DOI - 10.1002/fam.2437
Subject(s) - coal , coal dust , sieve (category theory) , autoignition temperature , particle size , dust explosion , environmental science , ignition system , atmosphere (unit) , particle (ecology) , moisture , coal mining , waste management , chemistry , environmental chemistry , mineralogy , combustion , materials science , meteorology , composite material , geology , engineering , physics , oceanography , mathematics , organic chemistry , combinatorics , aerospace engineering
Summary Flash fires and explosions in areas containing an enriched combustible dust atmosphere are a major safety concern in industrial processing. An experimental study was conducted to analyse the effects of atmospheric coal dust particle sizes and concentrations on the minimum auto‐ignition temperature (MAIT) of a dust cloud. Two different coal samples from Australian coal mines were used. The coal dust particles were prepared and sized in 3 ranges, of below 74 μm, 74 to 125 μm and 125 to 212 μm, by using a series of sieves and a sieve shaker. A humidifier was used to increase the moisture content of the particles to the required level. All the experiments were conducted in accordance with the ASTM E1491‐06 method in a calibrated Goldbert‐Greenwald furnace. The results from this study indicate that coal dust properties, such as the chemical nature (H/C), concentration, particle size (D 50 ), and moisture content, impact on the MAIT. For coal dust concentrations less than 1000 g.m −3 , the MAIT decreases with increasing coal dust concentrations. On the other hand, for low concentrations of 100 to 15 g.m −3 , the MAIT becomes more reliable for particle size D 50 rather than for volatile matters.