To determine the flame propagation mechanisms in titanium dust explosions, titanium particles at two concentrations were dispersed by air into a one end closed chamber to form dust clouds, and the mixtures were ignited by an electric spark. A high-speed video camera was used to record the flame propagation process and to obtain direct light-emission photographs. The flame temperature was detected by a fine thermocouple comprising 25-μm-diameter Pt-Pt/Rh13% wires. Based on the experimental results, the oxidation, combustion state and combustion mechanism of the titanium particles were analyzed. The propagation velocity and temperature characteristics of the combustion zone were also elucidated in detail. It was found that after ignition, the flames began to propagate quickly and emitted strong white light in the vertical chamber and the combustion state of the titanium particles strongly depended on the titanium concentration. Additionally, the flame propagation was faster and the temperature increased earlier and reached a higher value at a dust concentration of 1000g • m-3 than at 500g • m-3.
titanium particle cloud ; flame propagation behavior ; flame temperature