On predicting roller milling performance Part I: the breakage equation

The mathematical relationship (breakage equation) between the inlet and out let particle-size distributions of a roller milling operation is described, and the breakage function linking the two is defined. The forms of the bre akage equation and the breakage function are different for roller milling t han for other comminution operations, such as hammer milling or ball millin g. The breakage equation is discretised to give a matrix form, from which i t is demonstrated that during roller milling of wheat, particles break inde pendently of one another. This is an important assumption of breakage equat ions for many comminution operations and experimental results are presented , which confirm its applicability to the roller milling of wheat grains. Br eakage matrices are successfully used to predict the outlet particle-sire d istributions from First Break milling of wheat. Later papers in this series consider the form of the breakage function. (C) 2001 Elsevier Science B.V. All rights reserved.