油菜联合收获机组合式旋风分离清选参数分析与试验

Parameters Analysis and Experiment of Cyclone Separation Cleaning System with Replaceable Parts for Rapeseed Combine Harvester

摘要:

针对传统油菜联合收获机风筛组合式清选装置结构复杂、振动较大的问题，设计了一种组合式旋风分离清选系统，主要由抛扬装置、组合式旋风分离筒、吸杂管道、离心风机等组成，其中，组合式旋风分离筒包括上锥段、中间圆柱段、下锥段、可拆卸圆弧或锥形挡料板等部件。结合油菜脱粒分离装置中脱出物输出量分析计算得出抛扬装置主轴理论转速不小于569.6r/min，结合杂余分离最小风量需求分析得出组合式旋风分离筒出粮口直径小于256mm；基于运动学与动力学建立了单粒油菜籽粒在旋风分离筒稳定气流场中的运动方程组，分析了挡料板对籽粒分离的影响；以抛扬装置主轴转速、吸杂口风量为因素，以旋风分离系统清洁率与损失率为评价指标开展了单因素试验；开展了正交试验寻求抛扬装置主轴转速、吸杂口风量、上锥段锥角、挡料板形式、出粮口直径的最佳参数组合。单因素试验结果表明：抛扬装置主轴转速与吸杂口风量分别在500~700r/min、0.566~0.692m3/s范围内清选性能较优。正交试验结果表明：旋风分离清选系统清选性能影响主次因素为吸杂口风量（吸杂口风速）、挡料板形式、上锥段锥角、出粮口直径、抛扬装置主轴转速；最佳参数组合为吸杂口风量0.692m3/s、抛扬装置主轴转速600r/min、上锥段锥角30°、无挡料板、出粮口直径200mm；最佳参数组合与不同工况条件下，开展验证试验得出旋风分离清选系统清洁率和损失率分别为86.80%~94.45%和5.90%~7.73%。该研究为油菜联合收获机清选装置的结构优化和改进提供了参考。

Abstract:

In view of the complicated structure and large vibration of the screen combined cleaning device which utilized fan and sieve in the traditional rapeseed combine harvester, the cyclone separation cleaning system with replaceable parts was designed. The system was mainly composed of the blower, the cyclone separator with replaceable parts, pipe, centrifugal fan, etc. Moreover, all parts of the cyclone separator like the upper cone, cylinder part, lower cone, and arc/cone baffle inside were replaceable. Base on the amount of threshing outputs produced by the threshing and separating device of the harvester, the theoretical rotational speed of the blower was calculated, which was not less than 569.6r/min. To meet the minimum air volume requirement for separating the materials other than grain (MOG), it was concluded that the rapeseed outlet diameter of the cyclone separator should be less than 256mm. Based on kinematics and dynamics, the motion equations of a single rapeseed in the steady airflow field inside the cyclone separator were established, and the influence of the baffle on the separation performance of rapeseed was analyzed. Furthermore, the singlefactor experiment was conducted to find out the effects of the rotational speed of the blower, and the air volume of the MOG outlet on the cleaning ratio and loss ratio of the cyclone separation cleaning system. After that, the orthogonal was carried out to find the optimal combination of blower rotational speed, the air volume of the MOG outlet, the angle of the upper cone, the type of baffle, and the rapeseed outlet diameter. The results of the singlefactor experiment indicated that the cleaning performance was better when the rotational speed of the blower and the air volume was in the range of 500~700r/min and 0.566~0.692m3/s, respectively. The results of the orthogonal experiment illustrated that the primary and secondary factors affecting the cleaning performance of the cyclone separation cleaning system were air volume (air velocity) of the MOG outlet, baffle form, angle of the upper cone, rapeseed outlet diameter and rotational speed of the blower. The optimal combination of parameters could be obtained when the air volume of MOG outlet was 0.692m3/s, the rotational speed of the blower was 600r/min, the angle of the upper cone was 30°, no baffle was used, and the rapeseed outlet diameter was 200mm. Under this condition, the cleaning ratio and loss ratio of the cyclone separation cleaning system was 91.50% and 6.02%, respectively. To validate the performance of the cleaning system in actual production, the field experiment was carried out. There was no blockage existing in the blower, the cyclone separator, and the pipe. Finally, the range of the cleaning ratio and loss ratio was 86.80%~94.45% and 5.timization and improvement of the cleaning device for the rapeseed combine harvester.