Commercial aquaculture of tropical rock lobsters requires the precise and timely delivery of micro feed pellets to juvenile lobsters. These cylindrical pellets, ranging from 0.5 mm - 1 mm in diameter, are challenging to handle due to their small size. Current dispensing methods often rely on manually pre-loading compartments and time-based release mechanisms, which are labour-intensive and prone to inconsistency in both delivery time and amount delivered.
An auger-based dispensing system offers a promising alternative by enabling controlled release of discrete quantities of feed from a larger hopper, thereby reducing the need for frequent manual handling. However, designing such systems requires accurate prediction of pellet flow to ensure consistent delivery while avoiding breakage and bridging.
The Discrete Element Method (DEM) provides a powerful numerical simulation technique for analysing particle behaviour in pellet flows. Recent advancements in DEM have greatly expanded its range of applications and the capability to simulate particle breakage and adhesion.
This study presents DEM simulations using ANSYS Rocky of an auger-based micro pellet dispenser designed for lobster aquaculture. The hopper was initially loaded with 25,000 pellets with representative size distribution. Following this, the auger was rotated six times to ensure it was fully primed before completing 20 discrete revolutions to quantity the mass of feed delivered per rotation. The frictional characteristics of the particles were determined from an experimental drawdown test and the particle breakage was simulated using a Tavares breakage model. The results from this study demonstrate that the DEM can effectively predict feed delivery and pellet breakage. The DEM simulations can provide valuable insights into optimal auger designs and significantly reduce the need for extensive physical prototyping.