Parameter Optimization and Testing of a Conveying and Soil-Removing Device for Tiger Nut (Cyperus esculentus) Mechanical Harvesting

Aimed at solving the large power consumption and high operating cost problems associated with the process of harvesting tiger nuts, the use of a conveying and soil-removing device which removes sandy soil while conveying tiger nuts was proposed. The device was numerically simulated with and without vibration using EDEM software. The results showed that the vibrating force was more conducive to the complete removal of sandy soil and the effective conveyance of tiger nuts. The simulation testing was carried out using spiral speed, vibration amplitude, and vibration frequency as the independent variables and conveyance efficiency, sandy soil removal rate, etc., as the dependent variables. The test results showed that the optimal parameter combination was a spiral speed of 107 r/min, a vibration amplitude of 8.5 mm, and a vibration frequency of 10.7 Hz, under which the theoretical value of conveyance efficiency was 80.39%, the sandy soil removal rate was 84.61%, and the variation coefficient of sandy soil removal velocity was 3.6%. The field test determined that the relative errors of conveyance efficiency and sandy soil removal rate with theoretical values were 2.55% and 1.41%, respectively. The tiger nut damage rate was 1.16%, and the leakage rate was 0.52%. The results showed that the conveying and soil-removing device could meet tiger nut harvest performance requirements.