Solar Dryer with Reheating System for Annatto Fruit Pericarp

Abstract

Annatto fruit is one of the sources of natural food dye coming from its seeds. Aside from this part, the pericarp of the annatto fruit is a candidate for potential source of fuel. It is necessary for the pericarp to undergo drying prior to biomass energy conversion. The pericarp can be dried at least five days in sun drying to remove the seeds. In line with this, the researchers had designed a solar cabinet dryer introducing a reheating system and gravel used as thermal storage to lessen the drying time of the annatto fruit pericarp. The solar cabinet dryer had a multi layered wire mesh inside the drying cabinet that allows hot air from the collector to circulate and evenly dry the pericarp. Using the solar cabinet dryer, the drying time was lessened to seven hours with a drying rate of 4.37 g/min. The experiment compared three modes of drying consists of no reheating, with partial reheating and full reheating. During the drying process, several parameters such as the temperature, humidity and mass of each tray were measured, recorded and analyzed. It is found out that fully opened reheater has the highest moisture removed with 90.38% system efficiency.