Continuous measurement of convective heat flux during deep-frying: validation and application to inverse modeling
2003
Vitrac, Olivier | Trystram, Gilles | Raoult-Wack, Anne-Lucie | Fractionnement des AgroRessources et Environnement (FARE) ; Université de Reims Champagne-Ardenne (URCA)-Institut National de la Recherche Agronomique (INRA) | Ingénierie Procédés Aliments (GENIAL) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech-Conservatoire National des Arts et Métiers [CNAM] (CNAM)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | Programme Agro-Alimentaire (Cirad-Amis PAA) ; Département Amélioration des méthodes pour l'innovation scientifique (Cirad- AMIS) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)
This paper proposes a direct and continuous method to measure convective heat flux (phi(c)) during batch deep-frying, based on signal reconstruction techniques applied to local oil temperature measurements. The method was applied on the assessment of convective heat transfer of 1.5 mm thick cassava slices, for various conditions of stirring and oil temperature (140-160 degreesC), and validated independently from mass balance results on slices. Finally, frequency information on the dynamic of convective heat transfer was used to propose a mechanistic interpretation of internal coupled heat and mass transfer identified within thin materials. Three regimes of coupling were identified during the first minute of frying and were respectively related to (i) an unstable superficial vaporization with phi(c) values higher than 100 kW m(-2), (ii) a regular internal vaporization with phi(c) values oscillating between 15 and 35 kWm(-2) controlled by liquid water transport from core, (iii) a decreasing vaporization rate subsequent to the rapid vanishing of the saturated region.
Show more [+] Less [-]Bibliographic information
This bibliographic record has been provided by Institut national de la recherche agronomique
