Development and Performance Evaluation of the Neem Fruit Winnower

Neem (Azadirachta indica) fruits are an important source for oil extraction and biopesticide production; however, post-harvest cleaning is predominantly carried out manually due to the lack of crop-specific winnowing machines. The physical and aerodynamic characteristics of neem fruits differ considerably from those of cereal grains, making conventional paddy winnowers unsuitable for effective cleaning. In the present study, a power-operated neem fruit winnower was designed, developed and evaluated to improve cleaning efficiency and reduce labour dependency. The machine operates on the combined principles of airflow separation and mechanical sieving. The physical, mechanical, and aerodynamic properties of neem fruits were studied to guide the development of the winnower. Performance evaluation of the developed prototype was carried out under controlled conditions by assessing cleaning efficiency and cost economics. The winnower achieved a cleaning capacity of 125 kg h⁻¹ with a maximum cleaning efficiency of 92%. The operating cost of the neem fruit winnower was found to be Rs. 0.87 kg⁻¹, compared to Rs. 45 kg⁻¹ for conventional manual ground collection of neem fruits, resulting in a cost saving of approximately 97%. The results indicate that the developed neem fruit winnower is efficient, economical, and suitable for large-scale neem fruit processing, and can be effectively integrated with mechanised harvesting systems.