Comparaison d'un modèle empirique et d'un modèle physique de séchage de grains de maïs en lit fluidisé

Abstract

Comparison of two drying models applied to corn drying in fluidized bed. In this article, two predictive models of the temperature and water content of corn grains during their drying in a fluidized bed are compared. The first model is a simplified one, where the physical phenomena implied in the process are not described. It can be solved using freewares available on Internet. The second is a more complex model, based on the basic physical laws governing the phenomena of heat and mass transfer within the product. It requires the use of commercial finite element software to solve it. The two models are parameterized with four dryings where the temperature remains constant during the process, then validated on dryings with variable temperature and an intermittent drying. The two models are able to describe with an acceptable precision the evolutions of water content during continuous dryings, and to predict the evolutions of water content during dryings with variable temperature and the intermittent drying. The dynamic model is however not able to describe the evolution of the grains temperature during dryings at variable temperature with a precision lower than one degree Celsius. If this precision is sufficient, the use of the dynamic model will reduce considerably the costs in time and license of software for the modeling of the corn drying in a fluidized bed.

Keywords

• Drying
• modelization
• corn
• finite element method
• heat transfer
• mass transfer