基于气固耦合的气筛式马铃薯清选装置参数优化与试验

针对马铃薯联合收获后含杂率高、后续二次清选伤薯破皮严重等问题，对气筛式马铃薯清选装置进行了优化设计，在低损伤的同时保持一定的清选除杂功能，在阐述总体结构及工作原理基础上，结合马铃薯运动学模型和碰撞特性分析，得到影响除杂率和薯块损伤的主要因素，通过EDEM-Fluent耦合构建仿真模型，以风机出风口气流速度、摆抖筛摆抖形式、摆抖频率、筛面倾角为试验因素，以马铃薯清选率和洁净率作为评价指标，对清选过程进行了多组仿真，并依据仿真结果进行验证与优化。研究结果表明，清选装置风机出风口气流速度对马铃薯气力清选的可行性起着决定性作用，摆抖筛摆抖形式、摆抖频率和筛面倾角对清选效果影响大，影响由大到小为风机出风口气流速度、摆抖筛筛面倾角、摆抖筛摆抖频率，且摆抖筛前后简谐摆抖优于上下摆抖。最优工作参数组合：摆抖筛前后简谐摆抖、摆抖筛筛面倾角为25°、摆抖频率为10Hz、风机出风口气流速度为60m/s，此时仿真试验马铃薯清选率为93.1%，洁净率为98.7%，台架试验马铃薯清选率为91.6%，洁净率为99.2%。研究结果可为马铃薯清选装置设计与优化提供理论依据。

Parameter Optimization and Experiment of Air-screen Potato-stone Cleaning Device Based on Gas-Solid Coupling

At present, the rate of potato skin breaking after harvest was high and the content of impurities was high in China. In order to solve the problem that the rate of potato skin breaking was high, the content of impurities was high and the high cost of the above two points after the potato harvest, an air-screen type potato cleaning device was designed and optimized. By using the method of EDEM-Fluent coupling simulation, the air velocity at the inlet of the cleaning device, the swinging form of the shaking screen, the swinging frequency and the inclined angle were taken as the experimental factors, and the cleaning and separating rate and the cleanliness rate of the potatoes were taken as the evaluation indexes. Multiple sets of simulation analyses were conducted on the cleaning process, and validation and optimization were conducted on the basis of the simulation results. The simulation results showed that the wind speed at the inlet of the cleaning device played a decisive role in the feasibility of potato pneumatic separation. The order of significance of the impact was as following: the air velocity at the inlet of the cleaning device, the inclined angle of the shaking screen and the shaking frequency of the shaking screen, and the simple harmonic oscillation of the shaking screen was better than the up-down oscillation. The optimal working parameter combination was that the form of the simple harmonic swing of the screen was front and back, the angle of the screen was 25°, the swing frequency was 10Hz, the wind speed of the fan was 60m/s. Under the optimal working parameter combination, the potato cleaning and separating rate was 93.1% and the cleanliness rate was 98.7%. The results showed that the application of EDEM-Fluent coupling simulation was helpful to the research of potato cleaning and separating, and the research results could provide a theoretical basis for the design and optimization of potato cleaning device. At the same time, it laid a foundation for the further research on the size and shape of the opening of the shaking sieve. There was little difference between the bench verification experiment and the simulation experiment. The results of the bench verification test and the simulation test were basically the same, which laid a foundation for the follow-up field test.