OPTIMIZATION DESIGN OF TANGENTIAL FLOW-TRANSVERSE AXIAL FLOW DOUBLE DRUM MAIZE THRESHING DEVICE BASED ON EDEM

To address the problems of high kernel breakage rate and high unthreshed rate during direct maize kernel harvesting under conditions of high moisture content and dense planting - common in the single longitudinal axial-flow harvesters widely used in Southwest China - a tangential–transverse axial-flow double-drum maize threshing device was designed and optimized. The drum combination configuration was determined through theoretical analysis, and the influence of the vertical spacing between the two drums on threshing performance was investigated. The flexible concave screen and transition sieve plate were also redesigned. Using EDEM and Adams software, the threshing process was simulated and analysed to verify the rationality of the design. A prototype was fabricated, and drum speed, deflection angle, and feeding rate were selected as test factors. A response surface experiment was conducted with kernel breakage rate and unthreshed rate as evaluation indices. Multi-objective optimization of the regression model was performed using the response surface methodology (RSM). After rounding, the optimal parameter combination was determined as follows: drum speed of 453 r/min, deflection angle of 69°, and feeding rate of 6.7 kg/s. Verification tests yielded a kernel breakage rate of 2.76% and an unthreshed rate of 0.11%, meeting production requirements and providing a valuable reference for the design of maize threshing devices in Southwest China. 摘