Effect of ignition energy on dust explosion behavior: Phenomena of under-driving and over-driving

摘要

To improve the accuracy of dust explosion tests, systematic experiments were conducted by using a Siwek 20L vessel. Explosion behavior of typical light metal and carbonaceous dusts induced by different ignition energieswas explored. Both the under-driving phenomenon in the determination of thermodynamics and the over-drivingin kinetics were investigated. Results show that weak ignition source causes incomplete deflagration ofcarbonaceous dust, referred to as under-driving, which results in under-estimation in thermodynamics.Nevertheless, under-driving is not notable for light metal dust. Overly strong energy will cause over-driving sothat the measured kinetic parameter will be over-estimated. Also it is found that light metal dust is easier to beover-driven than carbonaceous. A dimensionless parameter was introduced to evaluate the occurrence ofover-driving. Authors suggest that the most appropriate ignition energy to gain realistic data in boththermodynamics and kinetics may be the energy at which the minimum dimensionless flame thickness is attained.