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

Area of Science:

• Agricultural Engineering
• Food Processing Technology
• Computational Science

Background:

• Sunflower seed dehulling requires efficient separation of shells from kernels.
• Existing methods may lack optimal efficiency in household-type shellers.
• Airflow-based separation is a key mechanism in seed processing devices.

Purpose of the Study:

• To enhance the shell-kernel separation efficiency in a household-type sunflower seed sheller.
• To optimize the air channel design and operating parameters for improved performance.
• To validate simulation results with physical experiments.

Main Methods:

• Coupled Computational Fluid Dynamics (CFD) and Discrete Element Method (DEM) simulations were employed.
• Air channel structure was optimized based on pressure and velocity analysis.
• Single-factor and orthogonal experiments were conducted to determine optimal parameters.
• Physical validation experiments were performed to verify simulation accuracy.

Main Results:

• Simulation accuracy was confirmed with P-values < 0.05 and relative errors < 3.00%.
• Optimal operating parameters were identified through experimental design.
• The optimized device achieved a shell-kernel separation rate of 89.91% at 6 m/s wind speed and 31° airway angle.
• The corresponding loss rate under optimal conditions was 6.24%.

Conclusions:

• The CFD-DEM coupled method accurately simulates sunflower seed shell-kernel separation.
• Optimized air channel design and operating parameters significantly improve separation efficiency.
• The study provides a validated approach for designing efficient seed dehulling equipment.