Optimising wheat first-break roller milling operation parameters using discrete-element method and response-surface methodology

This study investigates the effects of roller mill operating parameters on the first-break (1B) milling passage of wheat and optimises these parameters by combining the discrete-element method (DEM) and response-surface methodology (RSM). A contact model is selected, and a discrete-element simulation model is constructed for the fluted roll-wheat system. An EDEMpy program is developed to process the simulated data of the milled material. A Box–Behnken design with four factors and three levels is implemented, utilising the milling power of the roll, roll wear, and break release (BR) as response variables and operating parameters (roll gap, fast roll speed, differential, and feed rate) as experimental factors. The regression equations, variance analysis table, and interactive response-surface graphs of the influence of experimental factors on each response variable are obtained. The operating parameters are optimised using regression analysis. Laboratory grinding tests are conducted to validate the accuracy and reliability of the established discrete-element simulation model. This study introduces methodologies for investigating the wheat-milling process, offering insights for the operation of wheat first-break milling.