ABSTRACT

The design modification and performance evaluation of a fish feed pelletizing machine for low income farmers were carried out with the view to improve the performance of the existing pelletizing machine and introduction of a dryer. It mainly consists of the hopper, the mixer, pelletizing chamber, screw conveyor, pelletizing die plate, dryer and the power transmission unit. The fish feed pelletizer is powered by an electric motor and it works by the rotation of a screw auger which propels the feed mix to the mixer. The screw auger is enclosed in the auger casing and is propelled by an electric motor with the aid of belt and pulleys. This mixer is fed through a hopper, which is able to hold a large quantity ofthe feed mix at a time. The mixed feed is fed to the palletizer through an enclosed auger that propels it through the die hole which then releases the pallets to a dryer that dries and collects the palletized feed. The machine was tested using different die diameters of 2 mm, 4 mm and 6mm. The test was conducted at different moisture content of 10%, 15%, 20%, 25%, 30% and 35% wet basis. The machine test results showed that the pelletizing efficiency increases as moisture content and die diameter increase. The machine throughput also increases with both moistures. Content and die diameter. Highest efficiency of 98% was obtained when the moisture content was maintained at 25% wet basis and the feed materials were made to pass through 6 mm die diameter. Therefore, the improved fish feed pelletizing machine is recommended for use by small-scale fish feed production as the existing pelletizers have comparable higher losses couple with lower efficiency.