A glass transition temperature approach for the prediction of the surface stickiness of a drying droplet during spray drying

Benu Adhikari , T. Howes , Didier Lecomte (1) , B. R. Bhandari

1 RAPSODEE - Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement

The development of surface stickiness of droplets of sugar and acid-rich foods during spray drying can be explained using the notion of glass transition temperature (Tg). In this work, criteria for a safe drying regime have been developed and their physical basis provided. A dimensionless time (ψ) is introduced as an indicator of spray dryability and it is correlated with the recovery of powders in practical spray drying. Droplets with initial diameters of 120 μm were subjected to simulated spray drying conditions and their safe drying regime and ψ values generated. The model predicted the recovery in a pilot scale spray dryer reasonably well.

Mots clés: Spray drying; Stickiness; Safe drying regime; Powder recovery; Glass transition

Domaines: Sciences de l'ingénieur [physics]

Benu Adhikari, T. Howes, Didier Lecomte, B. R. Bhandari. A glass transition temperature approach for the prediction of the surface stickiness of a drying droplet during spray drying. Powder Technology, 2005, 149 (n°2-3), p.168-179. ⟨10.1016/j.powtec.2004.11.007⟩. ⟨hal-01847592⟩