Design, Development and Evaluation of Folding Type Pyramid Shape Solar Dryer for Bitter Guard Drying
O. S. Karpe *
Department of Electrical and other Energy Sources, Dr. Balasaheb Sawant Konkan Krushi Vidyapeeth, Dapoli, Maharashtra, India.
A. G. Mohod
Department of Electrical and other Energy Sources, Dr. Balasaheb Sawant Konkan Krushi Vidyapeeth, Dapoli, Maharashtra, India.
P. D. Phadtare
Department of Electrical and other Energy Sources, Dr. Balasaheb Sawant Konkan Krushi Vidyapeeth, Dapoli, Maharashtra, India.
Y. P. Khandetod
Department of Electrical and other Energy Sources, Dr. Balasaheb Sawant Konkan Krushi Vidyapeeth, Dapoli, Maharashtra, India.
R. T. Thokal
Department of Electrical and other Energy Sources, Dr. Balasaheb Sawant Konkan Krushi Vidyapeeth, Dapoli, Maharashtra, India.
R. M. Dharaskar
Department of Electrical and other Energy Sources, Dr. Balasaheb Sawant Konkan Krushi Vidyapeeth, Dapoli, Maharashtra, India.
*Author to whom correspondence should be addressed.
Abstract
Bitter gourd (Momordica charantia L.) is a perishable cucurbit crop used for culinary and medicinal purposes, but surplus production can contribute to post-harvest losses when preservation options are limited. This study focused on the design, development and evaluation of a folding-type, pyramid-shaped solar dryer for drying bitter gourd slices under natural convection. The dryer was designed with a 5 kg loading capacity, four drying trays and a total tray area of 2.4 m². Its dimensions were 1.50 × 1.50 × 1.40 m, and the main components included a drying chamber, drying trays, a loading door and an exhaust chimney. The foldable arrangement enabled assembly and disassembly by bolting and unbolting the main frame and removing the side frames. Performance was assessed under no-load and full-load conditions and compared with traditional open sun drying. The dryer achieved a maximum drying temperature of 65 °C. During winter testing, bitter gourd slices were dried to a final moisture content of approximately 5% on a wet basis in 13 hours, compared with 16 hours under open sun drying. The average drying rate in the solar dryer was 0.40 g/100 g bdm min. The overall drying efficiency was 28.48% during winter laboratory testing. Economic analysis indicated a benefit-cost ratio of 1.04, net present worth of Rs. 9080.85 and a payback period of 2 months and 8 days.
Keywords: Solar dryer, bitter gourd, pyramid dryer, design of solar dryer folding type pyramid shape solar dryer, moisture content, drying rate, efficiency