Virtual Booth

Traditional open-sun drying remains the most widely accessible method for post-harvest food preservation in rural communities, yet it inherently suffers from prolonged processing times, weather dependency, and high risks of microbial and environmental contamination. This project presents the design, fabrication, and experimental performance evaluation of a small-scale, solar-powered active food dryer developed to address these structural limitations. Engineered as a self-sustaining system, the physical prototype integrates a flat-plate solar collector with an enclosed multi-tier wire mesh tray drying chamber, utilizing a direct current (DC) exhaust fan powered by a solar photovoltaic (PV) panel to induce forced convection.

The experimental methodology involved systematic, multi-day outdoor trials conducted under the localized tropical climatic conditions of Sabah to analyze thin-layer drying kinetics using starchy agricultural matrices (Pisang Saba slices, 300g–500g batches). To isolate exact thermal and mass transfer efficiency gains, the performance of the engineered setup was evaluated across varying slice thicknesses (0.221 cm to 0.553 cm) under both passive (natural convection) and active (forced convection) operational modes, and directly benchmarked against a concurrent open-air control baseline.

Empirical results demonstrate that while passive greenhouse heat accumulation effectively elevated internal collector temperatures up to 68.4°C, boundary layer moisture saturation limited its comparative efficiency gains over open sun drying to a marginal 2.86%. Conversely, switching to the active mode broke down the moisture boundary layer via mechanical air regulation, successfully achieving a wet-basis moisture content removal efficiency of 54.18%—yielding a performance improvement difference of 22.23% over the open-air baseline. Furthermore, dynamic comparisons revealed that active mechanical forced convection completely overcame internal resistance and severe case-hardening phenomena typically experienced by thicker market-sized banana slices under standard outdoor conditions. The system also displayed robust thermal resilience during sudden weather transitions, acting as a protective shield that maintained food safety and minimized browning during localized cloud cover.

Ultimately, this study bridges the gap between solar thermal engineering and rural post-harvest management. The highly superior drying uniformity, reduced processing times, and enclosed sanitary processing environment offer a scalable, low-carbon, and compliant engineering solution (aligning with ISO 22000:2018 and ISO 9806:2017 standards) capable of mitigating waste, enhancing local food security, and improving smallholder economic resilience in developing regions.

 

link of presentation : https://youtu.be/FGiR-9NFe5w?si=LDM9Y4C4-KE8D61J