随动式秸秆还田与残膜回收联合作业机设计与试验.

The cotton areas in Xinjiang exceeded 2.5×106 hm² by the end of 2018, making Xinjiang the biggest cotton producer (accounting for 80% of the national cotton areas) in China. In most cotton fields in Xinjiang, the rows are spaced 560 - 760 mm and intra-row plants are spaced 96-100 mm. The average cotton yield in southern Xinjiang was approximately 7500 kg/ hm², compared with 6000 kg/ hm² in the north. Since Xinjiang is in hinterland of Eurasia, having ample sunshine, scarce precipitation and high evaporation, irrigation is essential to safeguard its agricultural production. To keep soil moisten, the planting strips for cotton are often mulched by plastic film before sowing seeds. Since natural degradation of plastic films is slow, an accumulative use of plastic film has led to soil structure degradation and environment deterioration. Recycling plastic film residuals is hence essential to developing sustainable agriculture but is challenging because the currently-used manual pick-up is labor intensive and inefficient while the available combine machines cannot separate the film residuals from cotton straw during the pick-up process. We designed a new machine aimed to solve this problem by combining film pick-up process and straw cutting-returning process. Differing from the available machines, the new one can separate the straw from the film residuals during pick-up and returning processes. It comprised a straw-cutting device, a film picking device and a film-lifting device, with all components purposely designed for cotton cultivated in Xinjiang. The operation depth of the film-lifting shovel was 54-178 mm. An orthogonal rotation test with three five-level factors was conducted to examine the impact of the speed of the spinning fling cutter, forward-speed and operation depth of the film-lifting shovel on passing rate of the crushing length, the residual film picking rate and the membrane miscellaneous separation rate from the straw. The variances were analyzed using Design-ExpertV8.0.6.1, and a regression model was used to evaluate the responsive performance of the machine to the above three operating parameters as well as their optimization. The results showed that the optimal spinning speed of the fling cutter was 1200r/min, the forward-speed was 4.5km/h, and the operation depth of the film-lifting shovel was 100mm. Field test results were consistent with these optimal parameters, with the straw crushing length pass rate being 89.37%, the residual film picking rate being 90.31%, and the membrane miscellaneous separation rate from the straw being 93.16%. It is manifest that the combine machine meets the technological requirements, improved plastic film residuals recycle efficiency and ameliorated their environmental pollution. [ABSTRACT FROM AUTHOR]