Research on the explosion behavior and flame evolution characteristics of LDPE powder with different sizes

The concentrated analysis of LDPE powder in combustion and explosion flame indicated that different aspect ratio of powder had different explosion characteristics, as well as flame evolution characteristics during combustion and explosion processes. In this paper, the explosion characteristics and decomposition behavior of LDPE powder with different aspect ratios were tested and analyzed, focusing on the flame evolution behavior and mechanism of LDPE powder with different aspect ratios during combustion and explosion. The results indicated that LDPE powder with low aspect ratio was more likely to be triggered, with a minimum ignition energy of 500 mJ and higher explosion pressure of 5.5 bar. The flame of LDPE powder with low aspect ratio was obviously extinguished during combustion and explosion, due to large powder suspension possessed hysteresis effect in discrete flame propagation, which led to poor combustion propagation of LDPE powder. The LDPE powder with low aspect ratio had a shorter combustion process of 78 ms. The decomposition of high suspended LDPE powder generated more combustible gas such as hydrogen, methane and ethylene, which intensified the explosion intensity and flame behavior. This paper provided a basis for the exploration of the behavior of explosive flame. The data and conclusions obtained in this article can provide certain theoretical guidance for the prevention and control of powder explosion caused by LDPE powder.