The Influence Of Initial Moisture, Retention Time, And Steam Quality In Two Conditioners On The Pelleting Process

Abstract

Pelleting of animal feed occurs extensively throughout the feed manufacturing industry. Steam conditioning plays an important role in any pelleting system, yet there is little research available to help understand this process. The overall objective of this research is to gain an understanding of what actually occurs during the mash conditioning process by examining the effects of mash moisture, retention time, and steam quality in two conditioners on the pelleting process and pellet quality. This experiment was conducted with a split-plot treatment structure within a CPM and Bliss conditioner. Mash moisture served as the whole plot treatment. Retention time (short and long), and steam quality (70, 80, 90, and 100%) made up the sub-plot treatments. Combinations of sub-plot treatments were completely randomized within the two mash moistures (12% and 14%). Three replications of all above combinations were completed. Data collection included moisture contents, pellet durabilities, energy consumption, and stt:am flow. The results of this study indicated that pellet quality, energy consumption, and steam flow were significantly related to mash moisture, retention time, and steam quality. The optimal operating performance was achieved through several combinations of treatments. For example, a short retention time combined with 14% mash moisture and using 70% steam quality produces high quality pellets at the lowest kWh/t. In contrast, a long retention time provided nearly equal quality pellets and energy consumption in combination with 12% mash moisture. It is important, however, to keep in mind that these results were obtained using a constant conditioned mash temperature of 82.2°C.