Optical Measurements of Dispersion and Ignition Effects on Particle Concentration in Constant Volume Dust Explosion Experiments

摘要

Many works have conducted research on how factors such as turbulence and equivalence ratio affect explosion parameters in constant volume dust explosions experiments. However, the literature lacks experimental work studying the development of particle concentration during the dispersal and ignition of the cloud. The current investigation uses a two-dimensional, time-resolved laser extinction technique to measure particle concentration during the aforementioned injection and ignition events. Measurements taken during the injection of titanium powder demonstrate the ability of the technique to provide qualitative images on the uniformity of the dust cloud. Analysis of the mean and standard deviation of the measured particle concentration provide quantitative information on the uniformity of the suspension. The technique is used to determine the effectiveness of anti-caking agents in the dispersal of sulfur powder. Measurements show that the addition of an anti-caking agent dramatically improves the dispersion characteristics but may not prevent agglomerations of sulfur at higher concentrations. Finally, the influence of pyrotechnic igniters on the concentration of inert, aluminum oxide particles is explored. Igniters releasing at least 40J appear to cause the alumina particles to breakup and increase the optical depth.