Design and experiment on cut roll feeding type horizontal shaft flail machine for banana pseudostem crushing and returning

Abstract: Banana as a famous tropical and subtropical fruit, is one of the four most famous fruits in the world, which is a monocotyledon herb belonging to the fruit of the genus Musa (family Musaceae). Banana pseudo stem is the by-product of the planting process. The biomass of banana pseudo stem can reach 27 million tons, which is calculated according to the 2 600 strains per hm2 and pseudo stem's fresh weight of 35 kg per strain. Therefore, banana pseudo stem is a large quantity of agricultural waste of tropical zones in China. The soil nutrients and organic matter can increase soil organic content effectively, and improve soil structure, quality and yield of banana by returning chopped pseudo stem to field in time. The straw shattering and returning technology research are mainly concentrated on wheat straw, corn stover and by-products of other crops in domestic, such as rice and cotton. There are problems such as the excessive consumption of machine power, cutting tool damaged easily due to the winding of stem fiber, which needs further improvement to the machine. In view of the above problems, this paper designed a horizontal-shaft returning chopped machine, which was suitable for the banana pseudo stem that was bulky, brittle and with high moisture content. This paper described the overall design of the machine, and determined the structure parameters and working parameters of main parts, such as pushing device, roll-cutter feeding device and chopped device. The movement and force analysis of chopped blade was also carried out. This machine composed mainly of down device, roll-cutter feeding device, chopped device, leveling device, suspension mechanism and hood. It will by overturn, cut broken feed, crushing returning and leveling four processes to deal directly with banana pseudo. Pushing device mounted on the front of the tractor. Roll-cutter feeding device, chopped device and leveling device connected together in order from front to back on the rear of the tractor. Chopped device located inside the hood, and constitute the grinding chamber with hood. In the course of their work, roll-cutter feeding device and chopped device driven by the power output shaft of the tractor rear, leveling device scrolling rely on friction of between leveling roller and the straw residue on the ground. And this machine can be adapted to different operating environments and operating requirements by adjusting the working height of the suspension mechanism. Field experiments indicated that the chopped percent of banana pseudo stem had reached 96.6% with the 21.4 L/hm2 oil consumption, and the 0.42-0.46 hm2/h efficiency of machine. When the tractor's forward speed reached 2.16-3.60 km/h, the back power shaft output the speed of 720 r/min. The chopped stem's average length of 57 mm had satisfied the agronomic requirements of returning straw. The machine has advantages of excellent performance, simple operation, safe and reliable work, and remarkable ecological and economic benefit, which has a broad prospect for the promotion in the banana planting areas of the south of China.