Bubble behavior of fructooligosaccharides syrup during the belt drying process

[EN] This paper is aiming to study experimentally the bubbling and drying characteristic of fructooligosaccharides syrup in the belt drying process. A series of bubble images were acquired by a high-speed image acquisition system during the drying process. By analyzing the characteristics of bubble and drying, the drying process of fructooligosaccharides was divided into three periods: boiling transfer, natural convection and conduction and diffusion period. The drying rate in different transfer stage was: boiling transfer > natural convection > heat conduction and diffusion. The results of the study are of reference value to belt drying.