Structural and parameter design of transverse multi-cylinders device on rice agronomic characteristics

Abstract

Rice panicles which have reached a mature state must be harvested, requiring differently specialized threshing devices and operating parameters to achieve favorable threshing and separating results. The primary objective of this study is to design a transverse multi-cylinders device that operates under the most effective possible variables to harvest rice in different states of maturity. The attachment forces between the grain and pedicel on the panicle were measured at different moisture contents. Based on rice agronomic characteristics, a transverse multi-cylinders device test bench was developed to conduct threshing and separating experiments. The threshing and separating capability of each transverse cylinder was tested, and the operating parameters of each threshing cylinder were investigated. Results showed that detachment force decreased from the bottom to the top of the rice panicle. Optimal harvesting time was identified at moisture content of 29.69%, and the best operating parameters combination was cylinder speed of 600, 650 and 700 rpm, and concave clearances of 40, 35 and 40 mm. Combine harvester of transverse multi-cylinder device test results showed an un-threshed grain ratio of 0.64%, un-separated grain ratio of 0.35%, and broken grain ratio of 0.22%, at a feeding rate of 6 kg/s. This research can be used in the future to successfully design transverse multi-cylinders device for small and medium-sized rice combine harvesters.