The Problem . Many farms in rural US have long narrow buildings that were built specifically to house and rear poultry and swine. The specifications of these buildings are dictated by the integrated poultry or swine business companies (referred to as integrators) who then contract with farmers to grow animals for the integrator. The integrator also typically supplies the farmers with chicks, poults, or piglets and feed; then collect the grown animals; after which they harvest, process and market the resulting products.
When the buildings age and become obsolete, or the integrator requires the farmer to make upgrades to their buildings, or the farmer loses the integrator’s contract: these buildings frequently have no alternate use and sit by idly to deteriorate with no means of generating income for the farmer. And farmers who have installed buildings over the course of time, either face the costly upgrades, or will not receive replacement birds (new flocks) as often as farmers or buildings that are performing at a high level for the integrator.
The Problem. The problem which needed to be solved in applying an aquaculture system to these buildings was that conventional aquaculture fish farm systems are too complex and expensive to allow the farmer to operate at an attractive rate of profitability or return of investment (ROI). Current systems have required complex plumbing and expensive water treatment equipment that are difficult to operate and are generally beyond the ability of small scale farmers to construct and operate profitably. A large percentage of catastrophic fish failures in RAS are because the water after being treated in the biofilter and gas conditioning steps does NOT return to the fish tank. Our design has all unit processes in a single tank container.
The Design. The basis for this design is that the influent is jetted perpendicular to the water surface with sufficient force to establish a rotary circulation about each cell’s center drain (cells are square in dimension). As a result, the standard raceway section is modified to create a series of horizontal counter rotating mixed cells. Hydraulic characteristics for a mixed cell raceway approximate that of a circular tank (mixed-flow reactor). Cell interaction was significant with cell to cell exchange rates representing about 3 to 4 times the tank inflow rate. This characteristic contributed to the observed uniform distribution of fish throughout the vessel. The energy requirement of the design was 1.32 m of water head primarily for the inlet system and jets. Given that the tank center drain in each cell is similar to that of a circular tank, the Cornell-double drain could also be applied in this design. Field evaluations have been conducted.