EXPERIMENTAL EVALUATION OF CHAIN-DRIVEN MESH BELT SORTING SYSTEM FOR MACHINE-PLUCKED FRESH TEA LEAVES

摘要

Due to the varying contents of machine plucked fresh tea leaves when harvesting in summer/autumn green tea at different times, they can only be used to produce bulk green tea, it is difficult to produce famous high-quality green tea, limiting the economic benefits of using mechanical plucking technology. In this study, a chain-driven mesh belt sorting system was developed to address the uneven quality grade of machine-plucked fresh leaves in order to grade high-quality leaves for famous green tea according to their shape and consistency. The operating parameters and the sorting effectiveness of the proposed method were evaluated using separation experiments. The results show that raw collected Grade-D machine-plucked fresh leaves can be sorted into Grade-A-, Grade-B, and Grade-C material by a series of four collectors. The mass of debris (old stems, leaves, fragments, or buds) in the final collector accounted for 94.38% of the remaining material, while 47.65% of leaves from the initial collector were separated out as one-bud-multi-leaves. The application of additional separation cycles using the same stage collector was found to further increase the classification of the separated high-quality tea leaves from Grade-A- to Grade-A to Grade A+. The results of these experiments reveal that the proposed system can classify fresh leaves according to their shape and tenderness, providing high-quality leaves for subsequent mechanized tea production and improving the economics of tea production. These findings are of considerable theoretical significance for the design of high-efficiency and low-damage automatic grading devices for machine-plucked fresh tea leaves.