Experimental study of the flame propagation characteristics of pulverized coal in an O2/CO2 atmosphere

The effects of the pulverized coal concentration, particle size, oxygen concentration, and initial combustion pressure on the flame propagation behavior of pulverized Shenhua bituminous coal have been investigated. The results show that the pulverized coal concentration and oxygen concentration have the same effect on the pulverized coal flame propagation speed. As the pulverized coal concentration or oxygen concentration increases, the pulverized coal flame propagation speed increases. As the pulverized coal particle size increases, the flame propagation speed decreases. Under pressurized conditions, for an oxygen concentration of 70%, the flame propagation speed of the pulverized coal gradually increases with increasing pressure (1-10 atm), and the increase becomes small after 8 atm. For oxygen concentrations of 30% and 50%, pulverized coal flame propagation no longer occurs when the pressure reaches 4 atm. Combined with the combustion parameters determined by thermogravimetry, the flame propagation speed of pulverized coal is positively correlated with combustion characteristics.