A coal dust explosion is one of the most severe mine disasters. An experimental investigation was conducted on coal dust explosions using a semi-closed Hartmann tube with anthracite. The dynamic propagation process of the flame was synchronously recorded using a high-speed camera and the schlieren technique to investigate the flame propagation characteristics in coal dust explosions with different concentrations. The results show that the propagation process can be categorized into three stages: ignition, flame acceleration and flame spreading. The velocity inside the tube exhibits clear symmetry, although the distribution is generally not uniform. The flame shape at the tube outlet is classified into three regions: the unperturbed zone, the preheating zone, and the combustion zone, which are affected by the guiding shock wave. With an increase in concentration, the preheating zone becomes thinner. At the same concentration, the flame propagation velocity at the tube outlet initially increases and then decreases. With an increase in concentration, the peak flame velocity at the tube outlet gradually decreases, resulting in a delayed peak time. The experimental results contribute to process safety and further explore the coal dust explosion mechanism to prevent the occurrence of coal dust explosion accidents.

煤尘爆炸是最严重的矿难之一。使用装有无烟煤的半封闭哈特曼管对煤尘爆炸进行了实验研究。利用高速摄像机和纹影技术同步记录火焰的动态传播过程，研究不同浓度煤尘爆炸中的火焰传播特性。结果表明，火焰传播过程可分为点火、火焰加速和火焰蔓延三个阶段。管内的速度表现出明显的对称性，尽管分布通常不均匀。管出口火焰形状受引导激波影响，分为三个区域：未扰动区、预热区和燃烧区。随着浓度的增加，预热区变得更薄。在相同浓度下，管出口火焰传播速度先增大后减小。随着浓度的增加，管出口处的峰值火焰速度逐渐降低，导致峰值时间延迟。实验结果有助于工艺安全，进一步探索煤尘爆炸机理，防止煤尘爆炸事故的发生。