Modeling and Analyzing of Energy Consumption in the Process of Wet Extrusion for aquaculture Feed

Abstract

Wet Extrusion is preferable to other feed-processing techniques in aquaculture feed processing except for high energy consumption. Specific mechanical energy (SME) is an important target to evaluate energy consumption.The objectives of this research were to develop the mechanism from work to heat transformation during extrusion process, and establish a model of energy consumption in the process of extrusion for aquatic feed. The experiment result indicated the theoretical model was reliability. Theoretic result was higher than experiment result, but the change trend was consistent. An adequate quadratic polynomial model for energy consumption was determined according to the optimization designs. The independent variables involved in the model were moisture content, screw speed and extrusion temperature. The effect of barrel temperature, screw speed and material moisture content on energy consumption was determined based on response surfaces. Moisture content (P < 0.1) and screw speed (P < 0.1) had significant effects on SME. Take no account of aquaculture feed, the final predicted minimum SME which was obtained with 29.7% moisture content, 140 r/min screw speed, 406.15K extrusion temperature.