Influence of multi-factor interactions on particle growth during top-spray fluidized bed agglomeration

Considering the strong dependence of agglomerate characteristics on various operating parameters, this study employs the control variable methodology (CVM) and response surface methodology (RSM) to investigate the influence of multi-factor interactions on particle growth during top-spray fluidized bed agglomeration. First, CVM is conducted to assess the effects of individual operating parameters on the agglomerate properties, such as mean particle size, relative width, and sphericity. Then, the interactive relationship between these input variables and the quality attributes of the process is investigated using RSM. The results show that the mean particle size increases with the increase of binder viscosity and spray rate, while it decreases with the increase of fluidization gas velocity and inlet gas temperature. The relative width of the particle size distribution increases with the spray rate, binder viscosity, and fluidization gas velocity, and hardly changes with the inlet gas temperature. The mean particle size is more sensitive to the binder spray rate at a lower level of fluidization gas velocity or a higher level of inlet gas temperature. The fluidization gas velocity corresponding to the maximum D₅₀ changes when the binder viscosity and binder spray rate are at different levels.