RELATIONSHIP BETWEEN ENERGY AND SIZE-REDUCTION OF GRAINS USING A 3-ROLLER MILL

The net specific energy consumption, NSEC (energy per unit mass of mil led product) and energy utilization, EU (energy per unit surface area of milled product) of a three-roller mill for grinding sorghum, wheat, and corn were evaluated. Four mill variables, namely fast roll speed, differential, roll gap setting, and corrugation configuration were co nsidered. The NSEC and EU both decreased as the fast roll speed increa sed. They increased as the roller gap setting was reduced and as the d ifferential speed decreased. When the rolls were set on dull-to-dull r ather than sharp-to-sharp configuration, the NSEC increased, but the E U decreased. Dimensional analysis was used to develop a mathematical r elationship between energy and size reduction for each type of grain i n a three-roller mill based on particle sizes of the material and mill ed products. The experimental data correlated well with the model.