A novel micro-spiral pneumatic selection system for the separation of fresh tea leaves

Abstract

Abstract There are no standard machines or systems used for grading the new tea leaves in the market, a micro-spiral pneumatic selection system was designed to separate fresh tea leaves, solving the difficulties in tea leaf selecting and separation. The system can flexibly separate the tea leaves continuously in high quality. And the simulation model was established based on the experiments results to optimize the design parameters. The maximum constant air flow rate separation tests showed that the symmetrical distribution effect of six tubular fans provided better balance than four tubular fans, and three grades of fresh tea can be differentially sorted. Additionally, solid particle simulation tests showed that separation begins at heights between 0.27 and 0.37 m. When the air flow rates range from 4.4 to 6.6 m/s, fresh tea leaves containing only one leaf per stem are well separated from multi-leaf containing stems. Furthermore, solid particle simulation tests indicated that different sizes of fresh tea leaves can be distributed in corresponding annular regions of specific widths; therefore, the flow field simulation tests showed that an optimized system could separate tea leaves according to the number of leaves on the stem. To sum, this study reported a novel micro-spiral pneumatic selection system with high efficiency for the separation of fresh tea leaves.