Simulation Analysis and Parameter Optimization of Seed-Flesh Separation Process of Seed Melon Crushing and Seed Extraction Separator Based on DEM

In order to enhance the comprehensive processing quality and production efficiency of seed melons, a seed melon crushing and seed-extraction separator has been developed and designed. Aiming at the issues of high impurity rate and scratch rate of melon seeds in the process of seed-flesh separation, the structure and parameters of the seed-flesh separation device were optimized in this study by simulation analysis and field testing. The simulation model of melon seed, melon flesh, and the seed-flesh separation device based on the discrete element method (DEM) was established, and the simulation parameters were calibrated. Subsequently, the melon seed impurity rate (G1) and the melon seed scratch rate (G2) were used as the evaluation indexes. The single-factor simulation test was carried out on the separation roller speed (A). The spacing between the scraper and the screen (B), the separation roller scraper inclination angle (C), and the influence rules of each factor on the separation effect of the seed-flesh were obtained. Finally, the three-factor and three-level orthogonal test was carried out. Using the method of ANOVA and multi-objective optimization, the optimal working parameters of the device were obtained as A-117.53 r/min, B-5 mm, and C-10 degrees, at which time the optimal evaluation indexes were G1-5.59% and G2-2.85%. The prototype test was carried out with the optimization results. The values of G1 and G2 were measured at 5.71% and 2.91%, respectively, and the relative errors with the simulation values were 2.15% and 2.11%, respectively, which were basically the same between the simulation model and the prototype test. The results indicate that the designed separation roller speed, spacing between the scraper and screen, and separation roller scraper inclination angle can meet the requirements of seed-flesh separation in the seed melon crushing and seed-extraction separator. The results of the DEM study can provide a reference for the optimal design of the seed-flesh separation device.