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.

CO EDITOR-IN-CHIEF:

• Hsiau, Shu-San

ASSOCIATE EDITOR:

• Liu, De-Shin

KEYWORDS:

• Banana straw crusher
• piranha teeth
• field test
• parameter optimization

Nomenclature

A	=	Forward speed of the machine
B	=	Rotational speed of the crushing shaft
C	=	Bending angle of the blade
m1	=	Total mass of banana straws in test areas
m2	=	Mass of banana straws with a length greater than 10 cm in test areas
n	=	Rotational speed of the crushing shaft
nmin	=	The minimum rotational speed of the crushing shaft
Q	=	Qualified rate of banana straw crushing
R	=	Rotational radius of the blade
R2	=	Fitting degree
T	=	Motion time
V	=	Forward speed of the machine
Va	=	Speed of the end position of the blade
Vmin	=	The minimum value of the speed Va
Vx	=	Speed of the end position of the blade in X direction
Vy	=	Speed of the end position of the blade in Y direction
ξ	=	Straw cutting rate
β	=	Bending angle of the blade
ω	=	Angular velocity of the blade

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was support by the specific research fund of the Innovation Platform for Academicians of Hainan Province [YSPTZX202110], the Academician Zhu Ming Station Foundation of Hainan Province [HD-YSZX-202103], and the National Natural Science Foundation of China [51965015].