Effects of ignition location on the characteristics of dust explosion venting at elevated static activation pressure

The effect of ignition location on the pressure characteristics of vented dust explosion was investigated in a 20 L chamber. For internal pressure, the proportion of the venting mixture with different ignition locations coupled with the wall quenching effect dominated the internal pressure curves. Besides, the maximum pressure rise rate was controlled by the residual amount of the fuel and induced turbulence. For external pressure, the ignition location dominated the delay time of the external explosion and the number of pressure peaks. Furthermore, the generation mechanism of pressure peaks was revealed by external pressure curves together with the visualization of the flow field. Eventually, it was found that both the internal and external maximum pressure with central ignition was larger than rear-end ignition and then the front-end. The corresponding dynamic mechanism was theoretically revealed, and a dimensionless prediction model for venting size and maximum external pressure was established.

Automated summary

The study investigated the effect of ignition location on the pressure characteristics of vented dust explosions in a 20 L chamber. Different ignition locations of the venting mixture coupled with the wall quenching effect dominated the internal pressure curves. The maximum pressure rise rate was controlled by the residual fuel and induced turbulence. The ignition location also influenced the delay time and number of pressure peaks in the external pressure.