Impact of Die Surface Holes Distribution Patterns of Fish Feed Extruder on Performance Indicators and Pellets Quality

Abstract

Die holes distribution is the most important factor of any feed pelleting system, as far as machine efficiency is concerned. This study was carried out with fish diet, where had been processed without steam addition (cold pelleting). The aim of the study was to explore the impact of fish feed extruder die surface holes distribution patterns on extruder productivity, total consumed power, specific energy requirements, pelleting efficiency, pellets bulk density and durability and economical evaluation. The optimum results were recorded with die that had holes distributed in the surface of die in star pattern, observed improvement in extruder productivity, pellets durability and pelleting efficiency by up to 10.75 and 15.64 %, 0.51 and 4.74 % , 0.53 and 1.63 %, respectively at constant moisture content of 36 % and screw speed of 96 rpm(12.7 m. min-1), comparing to triangular pattern and scattering pattern respectively, and decreased, bulk density, total consumed power, specific energy requirements and pelleting cost by up to 1.86 and 6.27 %, 14.98 and 47.34%, 12.2 and 6.2 % , 28.8 and 35.6%, respectively at constant moisture content of 36 % and screw speed of 96 rpm (12.7 m. min-1), compared to triangular pattern and scattering pattern respectively.