Model for Heat and Mass Transfer in Freeze-Drying of Pellets

Abstract : Lyophilizing frozen pellets, and especially spray freeze-drying, have been receiving growing interest. To design efficient and safe freeze-drying cycles, local temperature and moisture content in the product bed have to be known, but both are difficult to measure in the industry. Mathematical modeling of heat and mass transfer helps to determine local freeze-drying conditions and predict effects of operation policy, and equipment and recipe changes on drying time and product quality. Representative pellets situated at different positions in the product slab were considered. One-dimensional transfer in the slab and radial transfer in the pellets were assumed. Coupled heat and vapor transfer equations between the temperature-controlled shelf, the product bulk, the sub-limationfront inside the pellets, and the chamber were established and solved numerically. The model was validated based on bulk temperature measurement performed at two different locations in the product slab and on partial vapor pressure measurement in the freeze-drying chamber. Fair agreement between measured and calculated values was found. In contrast, a previously developed model for compact product layer was found inadequate in describing freeze-drying of pellets. The developed model represents a good starting basis for studying freeze-drying of pellets. It has to be further improved and validated for a variety ofproduct types and freeze-drying conditions (shelf temperature, total chamber pressure, pellet size, slab thickness, etc.). It could be used to develop freeze-drying cycles based on product quality criteria such as local moisture content and glass transition temperature.
Type de document :
Article dans une revue
Journal of Biomechanical Engineering, American Society of Mechanical Engineers, 2009, 131 (7), pp.074501. 〈10.1115/1.3142975〉
Liste complète des métadonnées

Littérature citée [14 références]  Voir  Masquer  Télécharger

https://hal-agroparistech.archives-ouvertes.fr/hal-01536947
Contributeur : Ioan-Cristian Trelea <>
Soumis le : vendredi 16 juin 2017 - 08:51:31
Dernière modification le : samedi 17 juin 2017 - 01:17:27
Document(s) archivé(s) le : mardi 12 décembre 2017 - 11:42:11

Fichier

Postprint Trelea Passot 2009 J...
Fichiers produits par l'(les) auteur(s)

Identifiants

Collections

Citation

Ioan-Cristian Trelea, Stephanie Passot, Michele Marin, Fernanda Fonseca. Model for Heat and Mass Transfer in Freeze-Drying of Pellets. Journal of Biomechanical Engineering, American Society of Mechanical Engineers, 2009, 131 (7), pp.074501. 〈10.1115/1.3142975〉. 〈hal-01536947〉

Partager

Métriques

Consultations de la notice

113

Téléchargements de fichiers

109