Characterization and modeling of cooling and drying of pellets for animal feed

Abstract

ABSTRACTThe process used to produce pellets for animal feed, especially the drying–cooling step, has not been extensively explored in the literature. However, with the increased industrial use of adjustable-speed drives to reduce fan energy consumption, the need for reliable simulation models has increased. In this work, different formulations of pellets were characterized and both their drying and drying–cooling kinetics were modeled. In comparing the results of the simulations with experimental results, the observed discrepancies were similar to the experimental uncertainties, indicating that our prediction tools yielded imperfect but acceptable results both in the thin-layer and deep-bed drying configurations. Furthermore, the approach centered on drying kinetics was also able to predict drying–cooling kinetics. This work suggests that one simple EMC equation, without temperature dependency, may correctly fit the behavior of several kinds of pellets and be sufficient for accurate simulations. The overall approach may be easily applied to many other kinds of pellets.