FACTORS AFFECTING THE PERFORMANCE OF AQUATIC FEEDS FLAT-DIE PELLETING MACHINE

Abstract

The overall goal of the present study is evaluating the performance of a local made flat-die pelleting machine to produce a strong and durable aquatic pelleted feeds with minimum cost. Some operating parameters affecting the performance of machine and pellets quality were studied. The flat-die pelleting machine was evaluated under two values of real hole diameter (4 and 5 mm),three different levels of formula particle size (1, 2 and 3mm), four values of die total thickness (25, 27.5, 30 and 32.5mm), three levels of roller clearance (0.5, 2 and 4mm) and three values of roller teeth width( 4, 6 and 8mm) using constant values of die speed of 300 rpm(4.71m/s), average ration moisture content of 15% (w.b) and hole entry diameter of 9 mm taking into consideration machine production rate, pellets quality (durability, bulk density) pelleting efficiency, specific energy consumption, economical costs of aquatic feed pellets mass and pellet water stability. From the obtained results ,the flat-die pelleting machine could be operate with particle size of 1mm, die total thickness of 32.5mm, roller clearance of 2 mm , roller teeth width of 8mm and real hole diameter of 4 mm to achieve the highest values of bulk density of 0.915 g/cm3,pellet durability of 95.38%,pelleting efficiency of 95.56%, and pellet water stability of 70% (up to 4 minutes in water) with values of production rate of 107.10 kg/h, consumed energy of 97.95 kW.h/Mg and pelleting total cost of 2386.58 L.E./Mg. Under the same operating conditions, the highest values of bulk density of 0.850 g/cm3,pellet durability of 91.65%,pelleting efficiency of 94.84%, and pellet water stability of 60% (up to 4min.) were recorded at real hole diameter of 5 mm with production rate of 143.65kg/h,consumed energy of 58.41 kW.h/Mg and pelleting total cost of 2374.72 L.E./ Mg.