Influence of Agitator Geometry in the Dissolution Kinetics of a Spherical Solid

An experimental study was conducted with the purpose of establishing the effect of both agitator geometry and agitation rate on the dissolution kinetics of spherical candies. To this effect, the dissolution constants were determined in aqueous solutions by way of the Hixson-Crowell model for three types of agitators, namely a paddle agitator with two blade, and two turbine agitators with four and six blades, respectively. Subsequently, for a fixed agitation rate, the temperature was varied in order to experimentally determine the activation energy of each agitator. It was found that, while the geometry of the agitator has an effect on the pre-exponential factors of the dissolution constant, the activation energy remains constant. Finally, differences in the dissolution constants as a function of the angular frequency of the agitator were also found.