Discrete element model construction and dehulling simulation verification based on harvested quinoa grains.

Area of Science:

• Agricultural Engineering
• Computational Modeling
• Food Processing

Background:

• Dry dehulling of quinoa presents challenges in process control due to poor visibility and unclear dynamic responses.
• Inaccurate simulation models lead to suboptimal settings and significant product losses during quinoa processing.
• Accurate simulation is vital for optimizing dehulling equipment design and performance.

Purpose of the Study:

• To develop and validate a discrete element method (DEM) simulation model for quinoa grain dry dehulling.
• To calibrate the bonding parameters of quinoa grains using experimental compression and shear tests.
• To simulate the dry dehulling process and evaluate the model's predictive accuracy.

Main Methods:

• Constructed a discrete element simulation model for quinoa grains using the three-axis spatial coordinates method in EDEM software.
• Employed Plackett-Burman, steepest rise, and Box-Behnken methods for compression test simulations to calibrate bonding parameters.
• Validated model parameters through mechanical shear tests and simulated the dry dehulling process in virtual equipment.

Main Results:

• The calibrated model showed a 0.32% relative error for maximum compression force and <5% for breaking shear force.
• Simulated dehulling rate (78.54%) and broken rate (1.38%) closely matched experimental values (75.32% and 1.24%).
• The model accurately reflected mechanical property differences between quinoa grain and pericarp.

Conclusions:

• The calibrated discrete element model provides accurate predictions for quinoa grain mechanical properties and dehulling behavior.
• This validated model offers a reliable foundation for optimizing the design of dry dehulling equipment for quinoa.
• The simulation approach effectively addresses challenges in understanding and improving the dry dehulling process.