INTERACTION OF KINETIC AND QUALITY ASPECTS DURING FREEZE-DRYING IN ANADSORBENT MEDIUM

A kinetic analysis of freeze drying by immersion in an adsorbent fluid ized bed process has been carried out and will be discussed in this pa per. The process is described based on a uniformly retreating ice fron t model in spherical geometry. The model needs to know both temperatur e and pressure driving forces, correlated as a function of water conte nt. The influence exerted by operational conditions on the heat and ma ss coefficients has been studied. Transport coefficients are correlate d as a function of the operating conditions to obtain equations that c an be used for predicting purposes in fluid bed freeze drying. Kinetic aspects are related to quality indicators determined through shrinkag e of product to select the most adequate operating conditions.