Flame propagation characteristics of mixed pulverized coal at the atmosphere of gasification

The leakage of pulverized coal easily results in fire and explosion accidents during coal gasification process. A vertical pipeline was built with the high-speed camera, micro-thermocouple and pressure sensor to obtain the characteristics of flame propagation. Based on the atmosphere of coal gasification, the effects of the spraying time, particle conditions, and rank of the pulverized coal were studied. The results show that the peak temperature, combustion pressure and velocity increase first and then decrease with the increasing of spraying time. When the particle size pulverized coal is 200 mesh, the peak pressure reaches the highest value. The flame propagation characteristics are similar at different concentrations of pulverized coal and the maximum appears at 333 g/m3. In addition, the peak temperature of the pulverized coal flame increases with the increasing of the proportion of long-flame coal in the mixed coal. The optimum characteristics of flame propagation appear at different ratios of mixed coal due to the effect of coal rank.