Abstract
This study was conducted to determine the coagulation rate of a freshly disseminated powder aerosol in the 10-micron size range when exposed to turbulent mixing conditions. A theoretical model was developed in which Smoluchowski's coagulation theory was extended to particles in the 10-micron size range by taking settling into account. Experiments were conducted in a chamber of 1 cubic meter with a binary aerosol composed of cornstarch and spray-dried saccharin particles. This approach was used so that agglomerates that failed to break up in the dissemination process could be distinguished from agglomerates formed in the aerosol state. The powders were pneumatically disseminated, stirred, and allowed to settle on glass microscope slides for subsequent counting. Binomial statistics were used to establish that the agglomerates were formed by random coagulation. The value of the coagulation coefficient was determined to be 3.6 × 10−5 cm2/sec.