Model for the deformation in agricultural and food particulate materials under bulk compressive loading using discrete element method. II: Compression of oilseeds Original Research Article

A simulation technique based on the discrete element method (DEM) has been applied to numerically model the bulk compression of beds of three oilseeds; canola, palm-kernel and soybean. A new code developed based on DEM principle using a non-linear viscoelastic contact law, real containing walls and particle deformation algorithm, which are typical of most agricultural particulates was used for the simulations. The model has been validated against experimental data using synthetic spherical particles and canola seed. It was then used to predict the bulk compression parameters during mechanical oil expression for the three oilseeds. Bed compression was simulated up to the oil point, which is the threshold pressure at which oil emerges from a seed kernel during mechanical seed-oil expression. Similar patterns in the variation of the characteristic parameters were obtained as observed in experimental data. The model was able to predict quite closely the bed strain at the oil point observed in experiment for each seed type. This suggests that the model is a useful tool in the study of mechanical seed-oil expression and other agricultural particulate compression processes as well as provision of data necessary in the design of appropriate machinery.