Estudo da cinética de secagem do girassol em secador de leito fixo.

Abstract

ABSTRACT: This work had as objective to study of the drying kinetic of sunflower seeds in three temperature levels (40, 60 and 80 °C) and drying air speed equal to 1.5 m s-1. The readings in relation to the sample weight loss had been carried through in regular intervals of 10, 30, and 60 min. The samples had been placed in a container made of metallic material and the weight loss was folloied until reaching constant weight. To study the drying kinetic behavior had been used the mathematical models of Page and Thompson. To Page model had been observed that the determination coefficient values are above 99%. This indicates that Page equation presents a great adjusts to the experimental data of the sunflower seeds. To Thompson equation had been verified that the determination coefficient values (R2) are greaters that 99%, except for the temperature of 80 °C, that presents R2 equal to 96.16%. It was observed that the drying kinetic was strong influenced by the temperature and that the use of raised temperatures significantly reduces the time necessary to dry the sunflower seeds. The models studied had adjusted to the experimental data of the drying curves, presenting determination coefficients (R2) with values bigger than 99%.