横轴对辊式棉秆起拔装置设计与试验.

Cotton, one of the main commercial crops in the world, mostly distributes in several major growing regions, including Xinjiang of western China. An important renewable biomass resource, the cotton stalk has received most attention to serving as the poultry feed, paper making, environmental protection materials, and biomass briquette fuel. Particularly, the highly efficient recycling of cotton stalk can be widely expected to bring enormous economic and ecological benefits. However, most previous treatments are focused on pulverizing cotton stalks and returning to the field. A great challenge is still posed on the current pulling machines for cotton stalks, with emphasis on operational requirements, leakage, and breaking rate. In this study, a novel horizontal-roller cotton stalk pulling machine was proposed to efficiently implement the pulling of the whole cotton stalk after harvesting. The machine was mainly composed of traction, gearbox, stalk conveying, transmission system, machine body, road wheel, spacing regulating mechanism, stalk pulling, dam-board, and support frame. Specifically, the power input shaft of the gearbox was connected to the power output shaft of a tractor. In working, the power was transferred to the chain drive by the power output shaft of a gearbox, and then to realize the stalk conveying and pulling operation under the rotation of the toothed belt and the opposite rotation of the stalk pulling roller. A systematic kinematic analysis was conducted to determine the influencing factors in the working process. A field test was also carried out in a farmland in Korla City, Xinjiang Uygur Autonomous Region of China in October 2019. The soil firmness was 467 kPa, and the moisture content of the soil was 15%-20%, due to the perennial drought and little rain in the study area. The average height of cotton stalk was 700 mm, while, the plant spacing was 50 mm in a wide and narrow close planting mode. The power was from a CFD604A wheeled tractor with a calibrated power of 44.2 kW. The test was performed on the national standard of a harvester combine test(GB/T 8097-2008). A three-level quadratic regression orthogonal test was designed, where the forward velocity of the machine, the rod velocity of the deflector, and the speed of the stalk pulling roller were selected as the influencing factors, whereas, the leakage rate and plucking rate were the response factors. A response surface method was utilized to establish the regression equations for the relationship between the factors and assessment indexes. An optimal combination of parameters was obtained, while an experiment was also conducted to verify the mathematical model. The test results demonstrated that there were great effects of factors on the performance of horizontal-roller cotton stalk pulling. The significant effects on the leakage rate were ranked in a decreasing order: the forward velocity of the machine, the rod velocity of the deflector, and the speed of the stalk pulling roller. Correspondingly, the significant effects on the plucking rate were ranked in a decreasing order: the speed of the stalk pulling roller, the rod velocity of the deflector, and the forward velocity of the machine. The verification test indicated that the leakage rate of the cotton stalk was 5.24%, and the plucking rate was 3.75%,when the forward velocity of the machine was 0.68 m/s, the rod velocity of the deflector was 1.75 m/s, and the speed of the stalk pulling roller was 221 r/min. The optimal combination was better consistent with the predicted one in model optimization, indicating a reasonable structural design. The findings can provide a sound reference for the structural design and optimization of operation parameters in the horizontal-roller cotton stalk pulling machine. [ABSTRACT FROM AUTHOR]