Development of Rotating Tray Dryer and Study of the Hot Air Flow Pattern with Computational Fluid Dynamics

• Main Authors: S. Murathathunyaluk, N. Srisakwattana, T. Saksawad, E. Bumrungthaichaichan
• Format: Article
• Language: English
• Published: AIDIC Servizi S.r.l. 2015-05-01
• Series: Chemical Engineering Transactions
• Online Access: https://www.cetjournal.it/index.php/cet/article/view/5046

Rotating tray dryer has the advantages over Cabinet dryer when we compare them, which is the end product from drying procedure has more regularity of moistness after the procedure. A new tray dryer with three rotating trays was designed, constructed and evaluated to find the optimal pattern for inputting hot air into the chamber. Three experiments to supply hot air were investigated. First, hot air flows in lower inlet tube with and without tray rotation. The comparison on hot air ratio with tray rotation was made by varying the ratio of air flow rate though three wall-side tubes at 0:0:100, 20:20:60 and 30:30:40 (upper: middle: lower). The optimal ratio was found to be 30:30:40. Next, this optimal ratio was used to compare the drying efficiency between entering hot air through one-way inlet with tray rotation (rotating tray) and entering hot air through two-way inlets without tray rotation (stationary trays). The optimal pattern for entering hot air is two-way inlets of hot air with stationary trays at the ratio of 30:30:40. This setting was used for drying of mulberry and measuring total phenolic compound (TPC) in dried mulberry. After drying process, the quantities of TPC in each tray were not significantly different. Furthermore, the optimal condition is used to study the temperature profile with simulation program (Computational Fluid Dynamics, CFD) and the results from CFD are correlated with the experiments.