Study on the influence of coal dust concentration on flame propagation characteristics of gas explosion in semiclosed tube

Abstract

ABSTRACT In order to deeply study the influence of the addition of coal dust on the propagation characteristics of gas explosion flame, in this paper, the frontal structure, front position, propagation velocity, propagation form, and duration of explosion flame produced by single-phase gas explosion and different concentration coal dust-gas coupling explosion are studied systematically. The results show that: when coal dust with different concentrations of 25~200 g/m3 is added, the time required for the complete development of the flame front of gas-coal dust coupling explosion is 50%~78.3% of that of single-phase gas explosion. In terms of propagation time, when coal dust with different concentrations of 25~200 g/m3 is added, compared with single-phase gas explosion, the time required for gas-coal dust coupling explosion flame to propagate from the ignition point to the outlet of the propagation tube will be shortened to varying degrees, with a range of 3.3%–28.6%. The addition of coal dust can greatly stimulate the development trend of explosion flame in the propagation tube. When coal dust with different concentrations of 25~200 g/m3 is added, the speed of explosion flame in the propagation tube will be increased in varying degrees, and the range of increase is 188% to 314.3%. After adding a certain amount of coal dust into the single-phase gas system, the overall duration of the explosion flame is greatly prolonged, and the flame oscillation phenomenon appears in the experimental tube.