Design and experimental validation of the high-speed counter-rotating thresher for pomegranate aril extraction

This study presents the design and experimental validation of a high-speed, drum-type pomegranate thresher driven by an innovative single-drive, multi-shaft transmission system. This design integrates crushing, feeding, and threshing into a compact unit, significantly reducing mechanical complexity and energy consumption. Finite element analysis verified the structural integrity of key components under operational loads. Systematic experiments identified an optimal speed of 220 r/min, achieving a threshing efficiency of 28.6 pieces/min, a peel removal rate of 88.3%, and an aril damage rate of 12.6%. The incorporation of a pre-crushing mechanism enhanced overall efficiency by 30.6%, a performance gain analyzed as a trade-off against a manageable increase in aril damage. The device demonstrated robust adaptability, processing fresh and stored pomegranates at rates of 33.9 and 27.9 pieces/min, respectively, while revealing critical correlations between pomegranate physical properties and threshing outcomes. This work provides an efficient and scalable solution for industrial pomegranate processing and establishes a foundation for future intelligent control systems.