Abstract: Tea plane circular sieve is one of the most important machines in tea sieving, it sieves the tea according to the size. The effect of sieving showed a great impact on the quality of the tea and the efficiency of tea processing. Based on the analysis on the motion path and sieve condition and sieving process of tea particles on the sieve surface was simulated by using discrete element analysis software PFC3D. Theoretical analysis and simulation results showed that: (1) the sieve permeation rate is related to tea motion path, relative radius vector of the sieve and the relative velocity, (2) there are different optimal circular speeds for different sieve mesh, (3) the sieve permeation rate can be improved and the motion path length of tea particles could be prolonged by increasing the radius of circle. The theory based on a single grain of tea is consistent with numerical simulation results of tea particles. It illustrated this theoretical analysis was suitable for tea particles sieving. The presented results provide the reference basis for the design and exploitation of tea plane circular sieve.

Key words: tea, tea plane circular sieve, numerical simulation, discrete element, PFC3D