水稻脱出物旋风清选分离筒中籽粒分离效率分析

旋风分离清选适用于小型水稻联合收割机,在保证清选损失率小的前提下,降低含杂率是设计的关键。为探寻分离筒中气流和籽粒两相流动规律,选取水稻脱出物中谷粒、颖壳、瘪谷、杂穗等为研究对象,利用Fluent软件对4LZ-0.8型水稻联合收割机清选系统中的旋风分离清选装置进行三维数值仿真模拟,分析不同工况下清选模型中各组分籽粒的运动轨迹,计算其分离效率。并以低损试验条件下谷粒清洁率为主目标进行台架试验,对最优模型进行了试验验证,评价扬谷轮转速、吸杂风机转速和分离组件距入口高度三因素与装置清选性能之间的影响关系,通过建立回归模型,进行多目标优化求解,得到较优参数组合:当扬谷轮转速为1 163 r/min,吸杂风机转速为1 920 r/min,分离组件距入口高度为63.26 mm时,预测所得谷粒清洁率为99.26%,可为清选装置再设计提供参考。

Separation Efficiency Analysis on Rice Extractions in the Cyclone Cleaning Segregating Cartridge#br#

Cyclone cleaning device is often used in small rice combine harvester. Its key design is to reduce the impurity rate on the premise of assuring lower cleaning loss percentage. In order to explore the 2 phase flow regulation between airstream and kernel in the segregating cartridge, three-dimensional numerical simulation of cyclone separation and cleaning device was carried out using Fluent software to analyze grain, rice hull, immature grain and miscellaneous grain in 4LZ-0.8 rice combine harvester cleaning system. The particle trajectories of each mixture in the model were selected and the separation efficiency was calculated. The loss rate and cleaning rate of grain were also tested in bench to evaluate the relationship between cleaning performance with the following 3 factors: winnower fan speed, vacuum fan speed and entrance height of detach components. At the same time, the combination of optimal parameter was found by multi-objective optimization solving with regression model. While the winnow speed was 1 163 r/min, the suction fan speed was 1 920 r/min, the entrance height of separation components was 63.26 mm, and the predicting cleaning rate was 99.26%, which provided references for the redesign of cleaning device.