Design and Testing of a Denucleation and Decortication Device for Lychee

Abstract . An automatic machine for lychee denucleation and decortication was designed to improve lychee processing efficiency and ensure the integrity of the lychee pulp. The main structure and operating parameters of this machine were determined by theoretical analysis and two orthogonal tests. The effects of the denucleation knife diameter, processing speed, and distance during denucleation and decortication were investigated. The denucleation rate, decortication rate, and juice loss rate were evaluated. The results of the processing tests showed that the denucleation rate was 94% when the diameter of the lychee fruit was between 29 and 33 mm, the diameter of the lychee seed was less than 10 mm, the diameter of the denucleation knife was 6 mm, and the processing speed of the denucleation knife was 0.5 m s-1. The decortication rate was 85% when the diameter of the baffle hole was 26 mm and there were eight grooves in the hole, yielding zero distance between the upper end of the decortication rod and the groove during operation. This machine is designed to perform automatic lychee processing, which includes the functions of denucleation, decortication, and lychee pulp separation. The processing speed of the machine is 600 kg d-1. This enhanced output is ten times greater than the output of conventional processing, and significant production costs are saved. Keywords: Decortication, Denucleation, Lychee, Processing, Pulp.