煤尘云着火敏感性影响因素的实验研究

In order to study the ignition sensibility of coal dust cloud, three kinds of typical pulverized coal-anthracite, bituminous coal and lignite-were chosen. And a Godbert-Greenwald oven was used to test the influence of different test conditions and coal dust types on the minimum ignition temperature (MIT) of coal dust and the suppression of coal dust cloud combustion by inert dust. The study found that the MIT of coal dust cloud first decreased and then rose with the increase of dust pressure. The optimal dust pressure was 50 kPa, on which condition the coal dust cloud ignition temperature arrived at minimum value. With the increase of coal dust particle size, the MIT of coal dust cloud showed a linear increase trend. With the increase of coal dust cloud concentration, the MIT of coal dust cloud decreased at first and then rose. For three kinds of coal dusts, all of them had a best ignition concentration. The best ignition concentration of coal-anthracite and bituminous coal was 1.818 g/L, and for lignite it was 1.364 g/L. The MIT of coal dust cloud decreased with the increase of volatility. For the coal dust which contained less than 15% volatility, the ash had obvious suppressive effect. When the content of volatility was more than 15%, the ash had little effect on the combustion of coal dust. The carbon black had the strongest inhibiting effect, coal fly ash had the second strongest inhibiting effect, and CaCO₃ had the weakest inhibiting effect on the MIT of coal dust clouds. The research results can strengthen the understanding of the combustion law of coal dust, and provide reference for the protection of coal dust fire and explosion and risk assessment of coal dust.