Design and test of vertical banana straw crushing and returning machine based on piranha tooth structure

ABSTRACT To improve the banana straw crushing rate, a new vertical shaft opposite-cut banana straw crushing and returning machine was designed. This study analyzed the structural characteristics of piranha teeth. Inspired by this, a bionic blade was designed to improve work efficiency. Through theoretical analysis, the main structural parameters of the key crushing components were determined. The main factors affecting banana straw crushing of the crusher were the forward speed of the machine, the rotational speed of the crushing shaft, and bending angle of the crushing blade. A three-factor three-level field test was carried out to obtain the optimal values for these parameters. The results showed that the optimal combination was the forward speed of 1.45 m/s, a rotational speed of 1600 r/min, and a bending angle of 150°. The qualified rate of straw crushing was 93.89% under the optimal working parameters. Repeated experiments showed that the optimal combination could meet the standard requirements. In conclusion, the new vertical straw crushing machine and its optimization of the selected parameters significantly improved banana straw crushing rate.