Design and Experimental Analysis of a Multi-Scale Fresh Tea Leaf Rotary Drum Screen Based on the DEM-RSM Method

Area of Science:

• Agricultural Engineering
• Process Optimization
• Material Handling

Background:

• Conventional rotary drum screens for fresh tea leaf classification face challenges like screen clogging and particle entanglement.
• Suboptimal operating parameters further hinder efficient and precise sorting of multi-grade fresh tea leaves.

Purpose of the Study:

• To present a high-performance rotary drum screen design optimized using a coupled Discrete Element Method (DEM) and Response Surface Methodology (RSM) framework.
• To address limitations in fresh tea leaf classification, enhancing sorting efficiency and precision.

Main Methods:

• DEM simulations were used to compare sequential and novel alternating screen aperture layouts.
• Single-factor experiments determined feasible operating ranges for rotational speed, inclination angle, and feed rate.
• RSM experiments quantified parameter interactions and developed a regression model for separation efficiency.

Main Results:

• The novel alternating screen aperture layout effectively mitigated particle entanglement and reduced clogging compared to conventional designs.
• Optimization identified optimal operating conditions: 13 r/min rotational speed, 5.5° inclination angle, and 300 leaves (0.132 kg) feed rate.
• The optimized design achieved an average separation efficiency of 70.49%.

Conclusions:

• The coupled DEM-RSM approach provides a robust theoretical foundation for innovating and optimizing fresh tea leaf classification equipment.
• This study advances the standardization and efficiency of primary tea processing through improved screening technology.