LOW HEAD INDIVIDUAL REUSE SYSTEM
A Low Head Individual Reuse System (LHIR), is described us a compact equipment attached to the tank and allows to do Degassing, Oxygenation and Water Pump with the same AirLift. This system allows us to modify Hatcherys that are operating in Open Flow convert these into Low Head Individual Reuse System (LHIR), without major complications.
Solids removal is done through the central discharge of the tank, this output is removed around 20 - 35% of the dirtiest water on the tank, which is reset and also serves to dilute the ammonium level in the main tank, this percentage of water taking suspended solids out of the system. When the solids are removed in early system does not occur fractionation feces or excess food, favored by the optimum rotational speed of the tank, this is due to high water flow, which guarantees 95% efficiency.
Degassing is done with the same AirLift Pump that moves water, this allows us to ensure a maximum of no more than 10 mg/lt of CO2 in each production tank, with average densities of 40 to 50 kg/m3. Oxygenation is also performed with the same AirLift Pump, this ensures that we will have an injection of not less than 30%, of the total required O2 by the system.
The large volume of treated water goes from a range of 1.5 to 2.0 times per hour, produces a speed of at least 20 cm / sec, this speed allows optimum self-cleaning of the tank. The power consumption for moving a flow of 1 m3 /hr is 0.0095 kw.
Flow Rate & Hydraulic in the Tank
The supply of fresh water is done independently directly to the production tank, this flow is measured with a flow meter, ensuring optimal use and control of water, in addition this make up control de Ammonia concentration, according with the feed rate, this make up water vary form 20% to 35% of the total water moved by the AirLift Pump.
As each tank production is maintained in a Single Reuse therefore it has its own treatment system, so there is no risk of horizontal contamination, obtaining much more robustness against health problems.
The sizes of fish farms is constantly growing as world production in aquaculture rises. Today, an average sea cage in the sea is producing around 5.000 tonnes of Salmon per year, just at one site. Land based systems have yet to be seen, but new recirculation projects for Salmon and Trout of these volumes are emerging:
A 2.000 tonnes Salmon farm in Hirtshals, Denmark. The system is based on Recirculation Technology and is covered by a building for completion, to control temperature and have high biosecurity. Salmon are grown from eggs to 4 kg size in two years in large tanks reaching almost 1000 m3 each.
A 3.000 tonnes Salmon farm on the Kintyre Peninsular, Tayiloan, Argyll, Scotland will start to grow the first salmon smolts from 100 grams to 5kgs. The fish will grow in highly oxygenated, recirculated water free from predators and parasites. The latest recirculation aquaculture technology is being supplied by a Danish firm.
A 4.000 tonnes Atlantic Salmon Atlantic Sapphire has one RAS salmon farming operation already up and running – in Denmark. The Florida operation will be their second. The majority shareholder in Atlantic Sapphire is Johan Andreassen, former founder and CEO of Villa Organic salmon farm in Norway. “ We were built on a vision to create what the seafood industry believed was impossible. To raise environmentally friendly Atlantic salmon. Guided by innovation and driven by our passion for sustainable change we have created the world’s first sustainable Atlantic salmon brand”.
Combining land based farms with cage farming is a very efficient way of production and probably the most competitive set-up. Smolts are produced on land in efficient and controlled systems (RAS) before they are released into large sea cages for grow-out. In some areas Cage Farming is not popular, and land based farms in the form of recirculation plants are seen upon as a future way of producing farmed fish. Although production cost are still higher than in cages, the systems have high food safety and complete control, and the output of salmon is constant and predictable.