Improving Post-Harvest Rice Drying Efficiency through a Low-Cost Halogen Dryer Design for Rural Communities

Abstract

Small-scale rice farmers in Sri Lanka often depend on traditional sun-drying methods, which are inefficient, weather-dependent, and contribute to significant post-harvest losses. This research focuses on the conceptual design and evaluation of a low-cost wet rice dryer using halogen lamps as the heat source, aimed at improving drying efficiency prior to milling. Field surveys were conducted to identify the common challenges faced by rural farmers, such as uneven drying, weather interruptions, and grain rejection by millers due to high moisture content. Based on the survey results, key user requirements were identified, including low operating cost, simple structure, and potential for multi-crop drying. A conceptual design was developed accordingly, with a drying chamber and tray system optimized for 1 cm thick rice layers. The full assembly was modeled in 3D using CAD software, allowing for virtual evaluation of airflow, heat source positioning, and accessibility. Finite Element Analysis (FEA) was applied to simulate the mechanical response of the tray under typical loads, confirming its structural soundness. Preliminary thermal experiments were conducted using a controlled test box setup to evaluate the heating performance of a 1000W halogen lamp. The system successfully achieved drying temperatures up to 82°C, suitable for surface moisture reduction. Temperature trends were recorded over time, and manual quality checks showed promising results for further development. These findings indicate the technical feasibility of the design and its potential to improve post-harvest efficiency in rural settings. The study provides a foundation for future stages of prototype fabrication, sensor integration, and field validation.