Simulation analysis and experimental testing of the grading performance of small potato grading device

Abstract

Existing potato grading device has a complex structure and a large volume, which is not suitable for small‐scale potato farmers. However, traditional manual grading methods not only have low efficiency but also high labor costs. This article developed a small movable rotating plate (MRP)‐type potato grading device, and the influences of three factors (the height of the horizontal slide, the tilt angle of the inclined slide, and the chain speed) on the grading efficiency and accuracy were investigated using the discrete element method and virtual orthogonal experiments. It was found that the horizontal slide height of 185 mm, the inclined slide tilt angle of 3.5°, and the chain speed of 0.9 m/s yielded the optimal grading efficiency (13.84 t/h) and grading accuracy (94.11%). Finally, the potato grading process was tested and validated through indoor tests, and the optimal grading accuracy was 91.04%. The grading accuracy deviation between the test and simulation results was less than 8%.Practical ApplicationCurrently, most commercial potato grading machines are designed for large‐scale farms, which are not suitable for developing countries. The potato grading device designed in this article can not only be used independently by small‐scale farms, but also be integrated with potato combine harvesters to achieve potato harvest and grading joint operations. This grading device has a simple structure, small footprint (1700 × 1200 × 840 mm3), and a very low cost ($600). With a high grading efficiency and accuracy, it can significantly improve the grading productivity of small and medium‐sized potato farmers in developing countries, reduce the production costs, and save labors.