Analysing the effect of particle size on the disintegration of distiller's spent grain compacts while drying in superheated steam medium

Particle size distribution (PSD) in distiller's spent grain compacts was varied and their effect on the disintegration characteristics of compacts while drying in superheated steam (SS) was monitored. Volumetric change and stress-relaxation characteristics, in terms of hardness and asymptotic modulus (EA) for a 40% deformation, were analysed during the warm-up period (5  s) and after reaching the moisture levels of 40, 30 and 20% (w.b.) in SS. Results showed that particle size was inversely correlated with the expansion or the increase in volume of the compact during SS drying, and the hardness as well as the EA of the compact increased with a decrease in particle size of the compact. A stepwise regression method was used to determine appropriate variables for developing a multiple linear regression model for predicting the EA of the compact.