密闭空间煤粉的爆炸特性

利用ISO6184/1和IEC推荐的20L球型爆炸测试装置,对4种规格的煤粉进行了系统的粉尘爆炸实验,探讨了煤粉的爆炸规律。得到了样品的爆炸下限浓度、最大爆炸压力,最大爆炸压力上升速率变化规律;分析了浓度、粒径、点火能量对煤粉爆炸猛烈度的影响。结果表明,粒径越小的煤粉,爆炸下限越小,而且在指定浓度下爆炸越猛烈。随着浓度的增大,最大爆炸压力和上升速率先增后减。样品3,峰值爆炸压力对应的浓度为400～1000g/m3,爆炸压力最大值为0.54MPa;点火头能量的增大在一定程度上促使反应更充分,从而爆炸强度更强。由于煤粉组成的特点,实验数据一定程度上说明了爆炸过程中气相燃烧的重要作用。 更多还原

Explosion characteristics of coal dust in a sealed vessel

Dust explosion experiments aiming at 4 kinds of coal dust were carried out in a 20-liter spherical vessel to explore the mechanism of dust explosion. The lower explosion limit, the maximum explosion pressure and the maximum explosion pressure rising rate were obtained for the coal dust samples. Influences of coal dust concentration, particle diameter and ignition energy on coal dust explosion intensity were analyzed. Results show that the lower explosion limit decreases with the decrease of particle size. For a given concentration, the coal dust with smaller particle size causes higher explosion pressure. Dust concentration has a significant effect on explosion intensity. The maximum explosion pressure and its rising rate increase first and then decrease with the increase of dust concentration. For sample 3, the peak explosion pressure is corresponding to the concentration range from 400 to 1 000 g/m3, and the maximum explosion pressure is 0.54 MPa. To some extent, higher ignition energy causes more sufficient reaction and results in more intensive explosion. Due to the features of coal dust sample components, experimental data indicate that gas phase combustion plays an important role during the explosion process.