Discrete element analysis of resistance plate effectiveness in abrasive-type rice milling machines on milling condition

The effect of resistance plates in an abrasive type rice-milling chamber on milling conditions was investigated using a two-dimensional discrete element simulation for the initial milling process. The decrease in brown rice mass was measured and rice particle movement was observed during milling in a horizontal-type test milling machine under two conditions; one in which the milling chamber was fitted with resistance plates and another in which the plates were absent. The model accurately reproduced the experimental results. Simulated information on the micro-mechanical behavior of rice particles revealed that the localized accumulation of particles in the area immediately anterior to each resistance plate resulted in an increase in both the contact number and shear force between individual particles and the abrasive roll, as well as greater abrasive action upon individual particles compared to when the plates were absent.