不同浓度煤尘云爆炸前后微观结构分析

Microstructure Analysis of Coal Dust Clouds with Different Concentrations before and after Explosion

运用20 L粉尘爆炸特性测试系统,实验研究了某一典型高挥发分煤尘的爆炸压力变化特性,并通过电镜扫描技术对其爆后残留物的微观结构进行了分析。通过研究得出:煤尘爆炸压力和压力上升速率随着煤尘云浓度的增加先增大后减小;平均粒径为19.45μm的煤尘,随着煤尘云浓度的增加,爆后残留物的孔隙率和粒径逐渐增加,且粒径随煤尘云浓度的增加呈指数增大的趋势变化。所得结论为认清煤尘爆炸机理及有效防治煤尘爆炸事故提供了重要的理论依据。

Based on the 20 L dust explosion characteristic test system, the explosive pressure variation characteristics of a typical high volatile coal dust under different concentration conditions were experimentally studied, and the microstructure of the explosive residue after explosion was analyzed by scanning electron microscope. The results show that the coal dust explosion pressure and pressure rise rate increased first and then decreased with the increase of coal dust concentration;the porosity and particle size of the residues exponentially increased with the increase of the concentration of coal dust cloud with an average particle size of 19.45 μm. The conclusions provide an important theoretical basis for the understanding of the mechanism of coal dust explosion and provide an effective prevention and control of coal dust explosion.