INFLUENCE OF DUCTING ON EXPLOSION PRESSURE - SMALL-SCALE EXPERIMENTS

This paper presents the results of experimental studies on the venting of gaseous and dust explosions in a 22 1 spherical vessel connected to a duct. Earlier observations of the strong sensitivity of gaseous explosions to the duct length have been confirmed and related to the acoustic oscillations in the system. The origin of the acoustic oscillations is not clear and their occurrence can be prevented by initial turbulence. Helmholtz oscillations have not been detected in the supercritical venting of an explosion. At a very stage of the explosion in the vessel a brief secondary explosion occurs but its influence on the explosion course is not clear. Because of the absence of acoustic oscillations in dust explosions their violence is much less affected by the length of the connected tube.