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 569.6r/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 256mm. 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 singlefactor 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 singlefactor experiment indicated that the cleaning performance was better when the rotational speed of the blower and the air volume was in the range of 500~700r/min and 0.566~0.692m3/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 0.692m3/s, the rotational speed of the blower was 600r/min, the angle of the upper cone was 30°, no baffle was used, and the rapeseed outlet diameter was 200mm. 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.
