Performance evaluation of a mixed-mode solar dryer Including porous media: A case study of lemongrass drying

Abstract

This study has the objective of evaluating the performance of a mixed-mode solar dryer including porous media and without porous media. A solar collector is a 60x120x10 cm³ flat plate and 55x30x5 cm³ porous media installed on the flat plate collector. The size of the drying chamber is 60x65x45cm³ and lemongrass is used to test. The studied factors are metal wire mesh with the porosity of 0.087, 0.134 and 0.1780. Samples are tested under natural sunlight conditions with wind speeds of 0.5, 1.0 and 1.5 m/s.
The performances of interest are the efficiency of the solar collector, moisture content, and drying rate of the lemongrass. From the study, the mixed-mode solar dryer which includes the porous media has higher performance than the one without the porous media. Moreover, the increasing porosity results in the increasing efficiency of the dryer because the moisture of the lemongrass is reduced and the average drying is increased.