The control mechanisms of lysine sulfate dust deflagration flame propagation based on flame microstructures and time scale analysis

Abstract

A series of experiments of the deflagration flame propagation of Lysine sulfate (LS) powder were conducted in a vertical tube with different moisture contents, particle sizes and mass concentrations. The thermal flame model was applied to investigate the dust flame micro-structures combined with the ion probes and the fine thermocouples. The time scales of the dust combustion sub-processes were calculated to reveal the control mechanisms during flame propagation. Results showed that a small amount of water significantly reduced the flame thickness and the heat transfer time, like the SEEP effects (Suppressant Enhanced Explosion Parameter). The practicability of applying the thermal flame model for dust flame was proved. As the mass concentration increased, the effect of the pyrolysis enhanced initially and then decreased during the gas phase combustion process, and the effect of heat transfer weakened during the pyrolysis process.