Design and Test of Threshing and Cleaning Device for Cyperus Esculentus L. Combine Harvester

In response to the challenges of difficult separation and incomplete cleaning during the mechanized harvesting of Cyperus esculentus L., a combined threshing and cleaning device consisting of a fruit-picking roller, a cleaning belt, and an air-screening system was designed. The structure and working principle of this device were explained, and the main components and operating parameters were determined through theoretical analysis. Using fruit-picking roller speed, cleaning belt angle, and fan speed as evaluation indicators, a three-factor three-level field experiment was conducted based on the Box-Behnken central composite design principle. Regression models between loss rate, impurity rate, and significant factors were established, and the optimal working parameters were determined using regression equations. The results showed that when the fruit-picking roller speed was 543.7 r/min, the cleaning belt angle was 50.3°, and the fan speed was 532.4 r/min, the loss rate of sesame seed harvesting was 2.67%, and the impurity rate was 2.49%. The results of field validation experiments indicated that the average loss rate of the combined threshing and cleaning device under the optimal parameter combination was 2.88%, and the average impurity rate was 2.41%, which were consistent with the optimization results of the regression model and fully met the requirements of mechanized sesame seed harvesting production.