Drying of solids; estimation of the mathematical model parameters

Abstract

In order to determine physical meaning of a thin-layer mathematical model parameter, the Page model was modified and tested on numerous experimental data. Applicability of the model was tested on the drying kinetics data, X(t), of 11 different types of the porous materials and dried in a convective, vacuum and/or microwave dryers under the predetermined external process conditions. During the entire drying time the drying kinetics of all the investigated materials and heating methods were successfully correlated with the modified Page model. The evaluated values of a new parameter, t k , corresponded to the time at which diffusion, as a governing mechanism of moisture movement through the material, started. The results were confirmed by the pore size distribution of some materials.Afin de déterminer la signification physique d'un paramètre de modèle mathématique des couches minces, le modèle de Page aété modifié et testé en utilisant de nombreuses données expérimentales. L'applicabilité du modèle aété testée en utilisant les données cinétique de séchage, X (t), de onze différents types de matériau poreux et séchés dans des séchoirsà convection, sous vide et/ouà micro-ondes dans des conditions de traitement externes prédéterminées. Pendant toute la durée du séchage, la cinétique de séchage de tous les matériaux et des méthodes thermiqueś etudiées aété corrélée avec succès avec le modèle modifié de Page. Les valeurs estimées d'un nouveau paramètre, tk, ont corresponduà l'heure où la diffusion,étant le mécanisme fondamental contrôlant le mouvement d'humidité au sein du matériau, a débuté. Les résultats ontété confirmés par la distribution des tailles de pores de certains matériaux.

Mathematical Modeling of Hot-Air Drying of Osmo-dehydrated Nectarines

“…Mathematical models applied in food dehydration can be classified as theoretical, semi-theoretical, and empirical models [37,38]. Theoretical models employ simultaneous equations of heat and mass transfer with food properties such as particle geometry, contraction, moisture diffusion coefficient and critical moisture content.…”

Drying of Pentaerythritol obtained from Batch Crystallization

“…Pore size distribution enables determination of the share of every pore size and their mean size, as well as the number of micropores which then shows whether the moisture is transferred through the porous material, either by capillary flow or diffusion [20,21].…”

Secagem De Granulado Mineral: Exploração Da Equação De Arrhenius Como Ferramenta Para Estimar a Energia De Ativação E a Difusividade Efetiva

“…Para a definição de cada zona, determinou-se o tempo crítico considerando duas abordagens diferentes. Em um primeiro momento, utilizou-se o modelo descrito por Sander et al (2010), baseado na Equação 6, para a determinação do tempo , que indica o tempo em que ocorre a transição entre os períodos de taxa constante e decrescente, correspondendo ao tempo em que o sólido atinge a umidade crítica.…”