FEED MOISTURE, RETENTION TIME, AND STEAM AS QUALITY AND ENERGY UTILIZATION DETERMINANTS IN THE PELLETING PROCESS

Abstract

Pelleting of animal feed occurs extensively throughout the feed manufacturing industry and steam conditioningplays an important role in this process. We investigated the effects of mash moisture, retention time, and steam quality in twoconditioners (manufactured by California Pellet Mill (CPM) Co. and Bliss Industries) on pellet quality, electrical energyconsumption, and steam flow rate during the pelleting process. Results of this study indicated that pellet quality, energyconsumption, and steam flow were significantly related to mash moisture (12 and 14%), retention time (short and long), steamquality (70, 80, 90, and 100%), and their interactions in mash conditioned to a constant 82.2
C. The maximum pellet quality(88% pellet durability) was achieved with two combinations of steam quality and retention time (70%short retention time,80%long retention time) for the 14% moisture mash using the CPM conditioner. A long retention time resulted in the lowestenergy consumption (kWh/t) during pellet production for the 12% moisture mash with the Bliss conditioner. Feed conditionedto 82.2
C using 100% quality steam required a lower flow rate (kg/h) than did the 70% quality steam for both conditioners.As competitive pressures continue in the global feed business, this study augments the manufacturers knowledge of how tocontrol this capital intensive cost center.