Effect of operation condition on the venting characteristics of gas/dust two-phase system explosions

Abstract

This experiment focused on the study of gas and solid two-phase explosions venting characteristics. A comprehensive research of venting parameter, venting flame propagation, temperature distribution, and the influence mechanism of operation condition were revealed. Results indicate that the venting flame experienced the changes of “mushroom”, “spherical” and “strip” structures and was affected by the initial pressure (Pinit) and the film rupture pressure (Pstat). As Pstat≥0.24 MPa, the flame all exhibited a “mushroom” structure and became more prominent as the film rupture pressure increased. The velocity history was increased in the acceleration venting stage as the film rupture pressure and initial pressures enlarged, and flame exhibited an obvious oscillation during extinguishing stage and the average amplitude was also enlarged. As the film rupture pressure further increased, the secondary and third venting processes appeared. The pressure change at the venting port was more significant, even appeared a larger negative pressure and its drop extent continued to increase as the film rupture pressure and initial pressures raised. Tmax appeared in the center of “spherical” flame approach the front end and the extinguished flame still maintained a higher temperature, resulting in a larger distribution outline than the flame image.