Modelling and Design of Indirect Solar Dryers for Batch Drying

Abstract

A model is developed to study the influence of design parameters (dimensions, air mass flow rate) in the performance of an indirect solar drier for batch drying. The aim of the work is to cover a wide range of configurations and sizes with a simple model. The model covers the air heating in the collector and the vapour mass transfer in the drying chamber. Constant rate controlled by convection mass transfer is assumed. The results, still preliminary, show the relevance of using a solar collector and the evolution of the drying process in the drying chamber. The obtainable vapour mass flow rate is calculated for a variety of configurations, showing the incidence of the air mass flow and the dimensions of the collector and the drying chamber. Performance parameters such as temperatures during the process and the efficiency of the drying chamber are also depicted.