Abstract
To develop a new type of air suction sorting equipment for tea, we performed a bench test using a high-speed camera for test shooting and data analysis and established a computational fluid dynamics–discrete element method (CFD-DEM) coupling model. The experimental results showed that under the same negative pressure and the initial fall distance from the adsorption surface, the multiscale tea leaves (collectively referred to as leaves) were adsorbed in the air suction flow field in different tracks, and the greater the mass difference of leaves, the greater the difference in their movement tracks. By using this feature, the multiscale machine-picked tea could be separated under the same negative pressure. The CFD-DEM coupling model was used to simulate and fit the motion locus points of the leaves in the same negative pressure flow field with different initial distance from the negative pressure adsorption surface. The results showed that the distance between the falling position of the leaves and the bottom of the negative pressure adsorption surface was proportional to the initial fall distance. The distance between the adsorbed leaves and the bottom of the negative pressure adsorption surface was inversely proportional to the initial fall distance. In summary, this research provides theoretical support for the future development of sorting equipment with suction for tea leaves.