Wang Dan, Ji Tingchao, Jing Qi, He Wei, Fan Zeyuan, Wu Dejian, Qian Xinming
State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China.
China academy of electronics and information technology, Beijing 100041, China.
J Hazard Mater. 2021 Jun 15;412:125108. doi: 10.1016/j.jhazmat.2021.125108. Epub 2021 Jan 14.
To reveal and improve our understanding of the ignition behavior and mechanism, G-G furnace experiments of three typical organic dusts were performed to investigate the minimum ignition temperature (MIT) in O/N, O/Ar and O/CO atmospheres with oxygen mole fraction from 8.4% to 50%. The experimental results were presented in oxygen-lean and oxy-fuel atmospheres to evaluate the ignition sensitivity of dusts in different atmospheres. It was found that CO is the strongest in terms of lowing the ignition sensitivity of the three dusts, and the dust explosion risk increases significantly with increasing O mole fraction for the three dusts through a logarithmically and significantly reducing MIT. However, for different dusts, inert gases show different suppression effects. In addition, a modified steady-state homogeneous ignition model was proposed and successfully applied to oxygen-lean atmospheres, and in oxy-fuel atmospheres, this model has also been improved to estimate the ignition mechanism. This ignition mechanism model could be used to successfully predict the minimum ignition temperature of high volatile dust under different inert atmospheres controlled by homogeneous ignition, which will provide a reference for the ignition hazard assessment of dust on hot surfaces.
为了揭示并增进我们对点火行为和机理的理解，进行了三种典型有机粉尘的G-G炉实验，以研究在氧气摩尔分数为8.4%至50%的O/N、O/Ar和O/CO气氛中的最低点火温度（MIT）。实验结果在贫氧和富氧气氛中呈现，以评估不同气氛中粉尘的点火敏感性。结果发现，就降低三种粉尘的点火敏感性而言，CO的作用最强，并且随着氧气摩尔分数的增加，三种粉尘的粉尘爆炸风险显著增加，这是通过对数方式且显著降低MIT实现的。然而，对于不同的粉尘，惰性气体表现出不同的抑制效果。此外，提出了一种改进的稳态均相点火模型，并成功应用于贫氧气氛，在富氧气氛中，该模型也得到了改进以估计点火机理。这种点火机理模型可用于成功预测在均相点火控制下不同惰性气氛中高挥发性粉尘的最低点火温度，这将为热表面上粉尘的点火危险性评估提供参考。
