Triple-effect new generation drying technique

Abstract

This paper introduces the triple-effect new generation drying technique that is defined as simultaneously swirling flow-fluidized bed-infrared drying process. It aims to perform the conceptual design of this innovative drying technology, and to experimentally investigate the drying behavior of green tea leaves by applying such a technique, and to develop the drying curve equations of the products in terms of the mathematical modeling, and to perform the quality analysis of the dried products. For these purposes, drying experiments were conducted for 100 W, 250 W, 500 W, 750 W and 1000 W infrared powers, and the parameters such as dimensionless moisture ratio, moisture content, mass shrinkage ratio, drying rate were calculated. Using the thin layer drying curve equations, mathematical modeling was performed by the assumption of thin layer since tea leaves perform swirling flow by forming thin layers in the annular form during drying. 13 evaluation criteria were considered for selection of the best model describing the thin layer drying curve of the product. Quality analysis was performed, considering the quality parameters such as water extract, total ash, total polyphenols, caffeine and raw cellulose of the dried green tea samples. As a result, it is determined that the best suitable infrared power is 500 W and the best thin layer drying model is Aghbashlo et al. model for the process, and the highest value of water extract is obtained to be 44.04% at 500 W in the process. Thus, it is expected that this study will contribute to the researchers, investors and policy makers for improvement and development of tea drying technologies in tea industry.