大型水平爆轰管中悬浮铝粉爆炸过程的实验研究

铝粉的燃烧与爆轰性能是粉尘爆炸领域研究的热点.利用长29.6m,内径199mm,配有40套喷粉扬尘系统的水平爆轰管,在40J电火花点火条件下,实现了悬浮铝粉-空气混和物火焰加速、爆燃、爆轰及其转捩过程,测得了爆炸波传播过程中的压力信号,并且观察到了爆轰波的稳定传播现象.实验结果表明,当铝粉浓度为300 g/m3时,在距离点火端10.15m(长径比L/D=51)处发生了DDT,测得的爆轰波传播过程中管内的最大爆速为1840m/s,最大峰值超压为10.5MPa.铝粉尘爆炸波在爆轰管内的传播过程可分为爆燃段、爆燃转爆轰(DDT)、爆轰增强以及稳态爆轰四个阶段.

Experimental Study of Suspended Aluminum Dust Explosion in a Large-size Horizontal Detonation Tube

Aluminum dust combustion and detonation properties have always been the focus in dust explosion domain. The process of flame acceleration, deflagration, deflagration to detonation transition (DDT) of aluminum flake dust-air mixture, was studied in an inner diameter 199mm and 29.6m long horizontal detonation tube. 40 sets of dust dispersion system were used to disperse flake aluminum into detonation tube. A 40J electric spark was used to ignite aluminum dust-air mixture. Self-sustained steady detonation was observed and pressure profiles were recorded, the characteristics of deflagration to detonation transition were studied. Experimental results indicate that the distance of deflagration to detonation transition is approximately 10.15m from ignition end (dimensionless transition distance L/D is 51). In detonation propagation process, measured maximum velocity is about 1840m/s, maximum overpressure is approximately 10.5MPa. The whole detonation propagation may be divided into 4 segments, including deflagration segment, deflagration to detonation transition segment, detonation development segment and steady detonation segment.