Unifying high-pressure grinding rolls models
Alex Thivierge, Jocelyn Bouchard, André Desbiens
Abstract
This paper unifies high-pressure grinding rolls crusher (HPGR) models of the working gap, mass flow rate, power draw, and centre and edge product particle size distribution models to produce a framework that allows the simulation of the equipment for process optimization and control studies. Calculating the model parameters requires exclusively a series of HPGR tests, but the framework prediction capabilities remain confined within the range of the calibration data set. The model inputs the specific force, the roll speed, the zero-gap and the edge width setting. It makes no restricting hypothesis regarding slip or material bypass and does not necessitate prior knowledge of the flakes density. The work presents an extensive model analysis with calibrations on 18 data sets with invariable moisture content and feed particle size distribution, which includes computing the parameter uncertainties and analyzing the residuals. Seven of these data sets are new, while the rest consists of previously published values. The analysis shows that the model performs satisfactorily for all data sets.