System dynamics and product quality during fluidized bed agglomeration of phytochemical compositions

Abstract

Pressure fluctuation signals linked to growth kinetics and fluiddynamic data were used to characterize system dynamics during fluidized bed encapsulation/agglomeration of phytochemical compositions using microcrystalline cellulose of two different sizes as seed particles. Two distinct operating modes were investigated: intermittent (interrupting the atomization of the feed composition for a specific period of time in order to reduce the system humidity) and continuous (without interruption the atomization of the feed). The increase in the agglomeration percentage to a certain value during the processes caused an increase in the standard deviation of the amplitude of the pressure fluctuation signals while the system remained stable, indicative of slight changes on solids circulation patterns. However, the standard deviation of the amplitude of the pressure fluctuation signals tended to decrease when agglomeration percentage reached a value able to affect significantly the system stability, in which agglomerates growth tended to cause the system collapse. This behavior was most evident for small size seed particles and continuous operating mode. The changes in the standard deviation of the amplitude of pressure fluctuation signals show strong evidence that this method would be able to detect alterations in system dynamics and can be a useful tool for process control and system monitoring.