Ignition sensitivity and flame propagation of zirconium powder clouds

Cao, Yong; Su, Hao; Ge, Lifang; Li, Yuyan; Wang, Yongxu; Xie, Lifeng; Li, Bin

Ignition sensitivity and flame propagation of zirconium powder clouds

2019

The ignition sensitivity and flame propagation of zirconium powder clouds are investigated with the influence of initial turbulence. The effect of initial turbulence on the zirconium powder explosion is studied by the change of ignition delay time and dispersion pressure. Hartmann apparatus and Godbert-Greenwald furnace are used to evaluate the minimum ignition energy and minimum ignition temperature, respectively. The high-speed camera is used to analyze the flame propagation behaviors of zirconium powder cloud. The experimental results show that the minimum ignition energy is between 1 mJ and 3 mJ and minimum ignition temperature is 503 K. The ignition energy reaches the minimum value of 30 mJ at the 0.7 MPa. The ignition energy with the effect of ignition delay time has revealed the similar rule. The maximum flame speed increases with the increase of dispersion pressure. Although, the instantaneous flame speed with the lowest dispersion pressure (0.4 MPa) is significantly higher than two others in the early stage of flame propagation.

Показать больше [+]