A deterministic approach for predicting the transformation of starch suspensions in tubular heat exchangers

Artemio Plana-Fattori (1) , Denis Flick (1) , Fabrice Ducept (1) , Christophe Doursat (1) , Camille Michon (1) , Samir Mezdour (1)

1 GENIAL - Ingénierie, Procédés, Aliments

Numerical modeling of fluid flow, heat transfer and transformation is conducted for an aqueous suspension of starch granules running throughout a four-heating-section tubular exchanger. The numerical model considers the transformation kinetics and the rheological behavior of the starch suspension as determined from laboratory work; further, the model includes the geometrical characteristics of the heat exchanger, as well as the operating conditions which were considered in running it. Model predictions are compared with results from experimental work, after sampling the starch suspension under thermal processing and later characterizing it using laboratory techniques. The numerical model predicts the bulk swelling state of the starch suspension at a level of agreement (−41% in volume mean diameter increase) which is better than the one reached after assuming plug-flow and radially-independent temperature (−66%). The inclusion of two-way coupling between the relevant phenomena constitutes therefore a positive improvement.

Mots clés: starch swelling; thermal history; rheological model; transformation of liquid products; continuous heat treatment; computational fluid dynamics

Domaines: Génie des procédés; Milieux fluides et réactifs; Ingénierie des aliments

Artemio Plana-Fattori, Denis Flick, Fabrice Ducept, Christophe Doursat, Camille Michon, et al.. A deterministic approach for predicting the transformation of starch suspensions in tubular heat exchangers. Journal of Food Engineering, 2016, 171, pp.28-36. ⟨10.1016/j.jfoodeng.2015.10.002⟩. ⟨hal-01232650⟩