Simulation and experimental study of shell-kernel separation device for household sunflower based on CFD-DEM coupling

In order to improve the separation efficiency of shell and kernel in a household-type sunflower seed sheller. The coupled research method of Computational Fluid Dynamics (CFD) and Discrete Element Method (DEM) was employed to simulate the shell-kernel separation process in the air channel. The main function of this shell-kernel separation device is to separate sunflower seed shells from sunflower kernels using airflow. This enables the dehulling of sunflower seeds, preparing them for subsequent processing or consumption.The air channel structure was optimized by analyzing pressure and velocity cloud images to enhance the separation efficiency. Comparison was made between the results of physical validation experiments and simulation experiments, including the shell and kernel separation rate, loss rate, and wind speed at the outlet. The P-values of the T-tests were less than 0.05 and the relative errors were all less than 3.00%, which proved the accuracy of the simulation experiments. Using shell kernel separation rate and loss rate as evaluation indexes, and air channel angle and wind speed as research objects, a single-factor experiment was conducted and the optimal range of each factor was determined. Based on the results of the single-factor experiments, orthogonal experiments were conducted, and the optimal combination of operating parameters for the device was determined using a comprehensive scoring method. A bench-scale validation experiment was conducted to verify the optimal combination of operational parameters. The results showed that, under the conditions of a wind speed of 6 m/s and an airway angle of 31°, the shell kernel separation rate reached 89.91%, with a loss rate of 6.24%.