Development and Performance Evaluation of a Low-Cost Solar Dryer for Drying of Mint Leaves

DOI: 10.22161/ijeab.113.21

Abstract:
The research was conducted to fabricate and develop a portable low cost solar dryer (LCSD) for the drying of mint leaves. The system was designed as a portable system for decentralized applications at various sites to satisfy the drying requirements of small farmers and co-operatives. The cross sectional area of the solar tunnel dryer was dome in shape, with length and width of 1.8 meters and 0.9 meter respectively. It comprises a collector section of 2.16 m2 and a drying section of 1.36 m2 and two chimney and three inlet to provide the required air flow rate over the perishable agricultural products to be dried. Transparent polythene cover of size 200 micron UV stabilized was used to close the dryer on top side to maintain the steady state air flow within the dryer. It has been observed that the drying air temperature was easily raised by some 20-25°C above the ambient temperature at air velocity ranges 0-1 m s-1. The efficiency of the solar tunnel dryer was found to be 19-20%.. Time taken by low cost solar drying and open sun drying was 240 and 390 minutes respectively. The color of dried sample was similar to fresh mint leaves and rehydration ratio was better than open sun drying. For low cost solar drying and open sun drying mint leaves sample the moisture diffusivity was 9.28×10-9 and 5.42×10-9 m2/s respectively. The process curves were found similar to a conventional dryer showing that this dryer can be successfully utilized for the drying of agricultural products using solar energy.

Keywords:
Low-Cost Solar Dryer, Drying Time, Moisture diffusivity, Colour, Rehydration ratio.

Article Info:
Received: 18 May 2026; Received in revised form: 14 Jun 2026; Accepted: 18 Jun 2026; Available online: 24 Jun 2026

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