The Prediction of Drying Uniformity in Tray Dryer System using CFD Simulation

Abstract

Tray dryer is the most extensively used because of its simple and economic design. In a tray dryer, more products can be loaded as the trays are arranged at different levels. The product is spread out on trays at an acceptable thickness. The drawback of this dryer is non-uniformity in the desired moisture content of end product due to poor air flow distribution in the drying chamber. Computational fluid dynamics (CFD) is used extensively because of its capability to solve equations for the conservation of mass, momentum, and energy using numerical methods to predict the temperature, velocity, and pressure profiles. This research is to predict drying uniformity of new design of the commercial tray dryer for agricultural product. The temperature and velocity profile, streamline and velocity on each tray was analysed to study the uniformity of the drying. The 3D simulation is done to represent the actual model. Generally the temperatures are considered uniform for all trays. However the average air velocity at several trays which is at tray number 1,7,8 and 15 are much higher than others tray. The rest of the trays are look more uniform. The average air velocity above the tray is about 0.38 m/s.