Extruder Design Changes Increase Production Capacity For Small-Diameter Feeds

摘要

The authors designed changes tor single- anil twin-screw extruders that streamlined the extrusion process to achieve higher output rates for small-diameter aquafeeds. The new technology moves the final screw close to the die and increases hole population for floating feeds, which yields higher capacities, increased percentage of floating feeds and greater expansion. An oblique tube die for higher sinking-feed capacity increases cooking, decreases expansion, controls pressure drop and increases retention time. Extruders have been somewhat limited in terms of capacity when producing small-diameter floating or sinking aquatic feeds. Extruders require restriction or die hole number limitation for developing the back pressure and energy required for product expansion and the cooking effect for floating feeds. Extruders also require more holes or a greater open area for reduced expansion for sinking feeds.