Solar Dryer

This work presents a complete design and performance analyses of a hybrid solar dryer consisting of a tunnel dryer, a shell and tube type paraffin based latent heat storage system, and a two-pass solar air heater under the prevailing weather conditions of Assam for drying of green chilli. The dryer has been designed for drying 10 kg of green chilli with initial moisture content of 750 % (db) to a desired moisture content of 10 % (db). The design calculation includes the estimation of required heat energy, air flow rate, quantity of paraffin wax, and areas of the solar air heater and the drying bed. The effects of air temperature, relative humidity, and velocity on the drying rate are studied. Parametric study of the air heater is also carried out to estimate the required length and thermal efficiency of the air heater.