The aim of the presented work is the investigation of the growth process in
a continuously operated fluidised bed granulator. For that purpose, granul
ation experiments were performed and system hold-up and particle size distr
ibutions were measured. For the interpretation of the results, a model was
developed taking into consideration the particle exchange between nozzle je
t and fluidised bed as well as the wetting and drying process. In contrast
to the commonly found assumption that droplet deposition is analogous to du
st deposition in fluidised bed filters, this model was developed to describ
e the processes in the nozzle region of a submerged nozzle that leads to a
system comparable to that of a wet scrubber. Consequently, the growth rate
as a result of the droplet deposition is found to increase with particle si
ze. (C) 2001 Elsevier Science B.V. All rights reserved.