Flame propagation behaviours in nano-metal dust explosions
Flame propagation behaviours in nano-metal dust explosions
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纳米金属粉尘爆炸中的火焰传播行为
DOI：
10.1016/j.powtec.2017.08.013
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发表时间：
2017-11-01
影响因子：
5.2
通讯作者：
Dobashi, Ritsu
中科院分区：
文献类型：
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作者：
Gao, Wei;Zhang, Xinyan;Dobashi, Ritsu
用高速摄影技术研究了40 nm钛、铝和铁粉尘云中火焰的传播行为。40个边缘的钛、铝和铁粉尘火焰的特征都是孤立的单一发光燃烧颗粒，具有光滑的球形锋面。在40 nm钛和铝颗粒的燃烧过程中，都发生了碎片抛射引起的“微爆炸”。在纳米尺度上，微米级颗粒的传热传质机制完全不同，从而导致了不同的传播速度。40 nm钛、铝、铁粉尘的平均脉动火焰传播速度分别为0.565 m/S、0.189 m/S和0.035 m/S。扫描电子显微镜分析表明，40 nm钛、铝和铁颗粒分别在液、气、固三相中燃烧。XPS分析表明，N-2在钛颗粒燃烧过程中起着重要作用。40 nm钛燃烧产物中含有43%的二氧化钛(Ti4+)、27%的二氧化钛(Ti3+)、21%的二氧化钛(Ti2+)和9%的TiN(Ti3+)。40 nm铝燃烧产物中含有100%的Al_2O_3(Al~(3+))，40 nm铁燃烧产物中含有49%的Fe_2O_3(Fe~(3+))、26%的Fe_3O_4(Fe~(3+)/Fe~(2+))、15%的FeO(Fe~(2+))和10%的Fe_2O_3。使用氮气作为防止纳米钛粉尘爆炸的方法是不可取的。(C)2017爱思唯尔B.V.保留所有权利。
Flame propagation behaviours in 40 nm titanium, aluminium and iron dust clouds were investigated by highspeed photography. 40 rim titanium, aluminium and iron dust flames were all characterized by discrete single glowing burning particles with smoothly spherical front. "Micro explosions" caused by the fragment ejection occurred in both 40 nm titanium and aluminium particles burning processes. At nano scales, the heat and mass transfer regimes were absolutely different with micro particles, which resulted in different propagation velocities. The average pulsating flame propagation velocities of 40 nm titanium, aluminium and iron dust clouds were 0.565 m/s, 0.189 m/s and 0.035 m/s, respectively. From SEM analysis, it was inferred that 40 nm titanium, aluminium and iron particles were burnt in liquid, gas, and solid-phase, respectively. From XPS analysis, it was found that N-2 played a significant role in titanium particles combustion. 40 nm titanium combustion products contained 43% TiO2 (Ti4+), 27% Ti2O3 (Ti3+), 21%TiO (Ti2+) and 9%TiN (Ti3+). While 40 nm aluminium combustion products just contained 100% Al2O3 (Al3+), and 40 nm iron combustion products contained 49% Fe2O3 (Fe3+), 26% Fe3O4 (Fe3+/Fe2+), 15% FeO (Fe2+) and 10% iron nonoxides. Inerted by nitrogen for preventing nano titanium dust explosions was inadvisable. (C) 2017 Elsevier B.V. All rights reserved.