Development and Evaluation of a Motor-Operated Winnower for Small and Medium-Scale Paddy Farmers

Abstract

Winnowing is the process of separating grain from chaff and other impurities using a natural breeze or a mechanical air flow. In the present study, an existing tractor-operated winnower was modified into a motor-operated unit. A 1-HP AC motor was installed to drive the winnower, with its rotational speed regulated through a motor speed controller and the existing transmission system. The performance of the modified winnower was evaluated as per standard testing procedures to assess its feasibility and efficiency. Key performance parameters examined included cleaning efficiency, output capacity, blown grain percentage, and cost of operation. The results indicated that the air velocity of both tractor- and motor-operated winnowers was approximately three times higher than that of manual winnowing at the optimal dropping height of 121 cm from the ground and 60 cm from the fan center. Grain moisture content was found to have a significant influence on winnowing efficiency, which increased as the moisture content of the grain and chaff decreased. The motor-operated winnower achieved a cleaning efficiency of 97%, an output capacity of 95 kg/h, and a blown grain loss of 9%. The operational costs were calculated as ₹300 for the tractoroperated winnower and ₹88 for the motor-operated unit. Overall, the study demonstrates that the motor-operated winnower is a cost-effective, energyefficient, and practical alternative to both manual and tractor-operated systems.