Drying Nerium Oleander in an Indirect Solar Dryer Using Phase Change Material as an Energy Storage Medium

Abstract

In this work, the Nerium Oleander was dried at its prescribed drying temperature (50±2.5 ºC) in indirect solar dryer (ISD) using phase change material (PCM) as energy storage medium. 12 kg of paraffin wax were used as a latent heat thermal storage. From the experimental obtained results it is found that the ISD implementing PCM as thermal storage medium successfully maintains the temperature of drying air around 50 ºC for seven consecutive hours. It is also found that the temperature of drying air is higher than ambient temperature by 2.5-5 ºC after sunset for 5 hrs at least. This profile of the temperature of drying air helps reaching the final moisture content of Nerium Oleander after 14 hrs. Nine thin layer drying mathematical models were tested to specify the suitable model for describing the drying behavior of the Nerium Oleander. It was found that Midilli and Kucuk model is convenient to describe the thin layer solar drying of Nerium Oleander.