Design, Development and Performance Testing of Hand Operated Groundnut Decorticator

Abstract

In Lake Tana, Ethiopia, influx of nutrients has resulted in excessive growth of water hyacinth (WH) in the last decades, which has also caused economic and environmental problems. Although enormous labor and financial resources used to control this overgrowth, these were still not enough to suppress the excessive growth of WH.  This study examines the design, development and performance evaluation of a wooden groundnut decorticator designed for small-scale rural farmers. Groundnut, a vital legume crop, is widely cultivated in tropical regions, offering significant nutritional and economic value. However, traditional hand-shelling methods in Ethiopia are inefficient, labor-intensive, and lead to health issues like "sore thumb syndrome." The objective of this research is to design, develop prototype and performance test of groundnut decorticator.  The decorticator was constructed using timber, wire mesh, and paddle mechanism that operated manually for shelling the groundnuts. Performance tests were conducted using various input amounts (1, 1.5, and 2 kg), and key parameters such as shelling percentage, damage percentage, unshelled nuts, and shelling efficiency were recorded. Results showed an average shelling percentage of 92%, the damage rate of 4%, and efficiency of 15 kg/hr, which is higher than traditional hand-shelling of 3 kg/hr (from experts’ opinion).

The findings indicate that moderate input quantities of groundnuts yield the best balance of shelling performance. The wooden decorticator, constructed from affordable, local materials, presents a valuable tool for rural farmers, saving time, reducing labor, and enhancing productivity. Further modifications could explore motorization for larger-scale use.