Optimized design and experiment of a tea screening machine using EDEM software

At present, the tea screening machine has problems such as a low screening rate and a high false screening rate, which greatly affect the quality and economic benefits of tea products. To solve these problems, the screening process of the tea screening machine was numerically simulated using the discrete element method (DEM). The motion law of tea material on the sieve surface was analyzed. Meanwhile, the effects of crank radius (A), crank speed (B), and screen surface inclination angle (C) on screening ratio and false screening rate were studied. Additionally, an orthogonal rotation experiment was designed, and the significance of each factor was analyzed using response surface methodology (RSM). Quadratic polynomial optimization models were established to obtain the optimal parameter combination. The optimization results showed that, with A, B, and C set to 39 mm, 186 rpm, and 5.8°, respectively, the optimal values for the screening ratio and false screening rate were 98.50% and 3.47%, respectively. The prediction results of the established regression equation deviated from the experimental results by less than 5%. This study can provide a reference for the optimization design of the tea plane screening system.