In order to create optimal living conditions in the fish farm, a continuous supply of oxygen is required throughout the entire system. This includes the hatchery, conditioning and cultivation areas. However, this requirement is not easy to fulfil, especially with complex circulation systems. Austrian fish farm Moser therefore opted for a customised solution consisting of a BOGE compressor and INMATEC oxygen generator. This ensured precise oxygen dosing and energy-efficient supply to the tanks.
From egg to food fish, the Moser fish farm is characterised by its closed production chain. The company in Zillertal is a family business that highly values sustainability, resource efficiency and quality. Trout and char species are bred on an approx. 1,800 m² production area in a state-of-the-art recirculation system, which was newly built in 2023. The technology enables continuous monitoring and adjustment of the water quality, ensuring optimum growth conditions for the fish. Depending on the species and end product, the fish spend between six and 14 months in the facility. The breeding is divided into six nursery tanks, and the fish are moved to the fattening channel depending on their size. The fish ready for sale are kept in the cultivation section. In addition to the recirculation system, the farm also uses five natural ponds, which provide a species-appropriate habitat for trout, char, catfish, sturgeon and carp.
Challenges in fish farming
In the farm’s recirculation system, the oxygen content must remain constant and precisely controllable in all tanks – even with varying fish sizes, different water temperatures and fluctuating water flows. This requires a continuous supply of oxygen, which must be of high purity. The compressed air produced for oxygen generation in the compressor must have a low level of humidity so as not to corrode the system or allow bacteria or mould to grow. The residual oil content must also be very low. These requirements demanded a solution that would work precisely with the existing control technology and at the same time be able to respond automatically and quickly to fluctuations, even at high load peaks. Another important criterion was the size of the system, as the available plant rooms were limited. The solution had to be compact and low-maintenance in order to ensure efficient operation in the long term and to keep maintenance to a minimum. The aim was to produce a system that simultaneously met the requirements for precision, reliability and energy efficiency. In BOGE, the Moser fish farm has found the right premium supplier that delivers both the compressed air supply and oxygen generation with the systems from INMATEC, the leading manufacturer of nitrogen and oxygen generators, which has been part of the BOGE family since August 2023.
Reliable compressed air and oxygen generation
The BOGE compressed air system comprises a frequency-controlled C15-2LF screw compressor with a rated output of 15 kW. To ensure constant compressed air quality in accordance with ISO 8573-1, the system features a conditioning unit. A 500 litre compressed air receiver provides the necessary buffering, while a DT 26 refrigerant compressed air dryer with pre-filter prevents condensation and corrosion. An activated carbon absorber with microfiltration ensures a high level of air purity to preclude dirt and impurities in the system. The INMATEC PO 150 oxygen generator, which has a capacity of 7.8 Nm³/h with a purity of 90%, is used to supply oxygen. Using the principle of pressure swing adsorption (PSA), compressed air passes through various filters to remove dirt and impurities such as dust, oil and moisture. The purified air then enters an adsorption tank filled with a special material. This adsorbs nitrogen at high pressure, while oxygen molecules are allowed to pass through. The oxygen generated in this way is fed into a 250 litre tank and then directed straight into the tanks of the circulation system via piping with finetuning valves. The automated oxygen dosing is a key feature: by integrating sensors that continuously measure the oxygen content in the water, the supply is automatically adjusted, especially during events such as feeding, when the oxygen content drops rapidly and has to be adjusted accordingly. "Optimum conditions in our trout and char farming are between 7.5 and 9.0 mg/l of dissolved oxygen," says Franz Josef Brindlinger, owner of the fish farm. “Stress reactions begin below 6.5 mg/l – therefore, seamless control and automatic replenishment are essential.”
Precise, reliable and energy-efficient operation
One of the solution's greatest strengths is its real-time regulation of the oxygen supply. Not only does it ensure stable and healthy conditions for fish growth, it also reduces the need for manual intervention. This increases operational safety. Another advantage is the reliability and energy efficiency of the system. The frequency-controlled screw compressor and the oxygen generator are designed for a long service life. Controlling production in line with demand avoids unnecessary energy consumption because only as much oxygen is produced as is needed. Further savings are achieved through heat recovery, which utilises the warm exhaust air from the compressor to heat the plant rooms. This helps reduce heating costs and makes the operation more sustainable. Easy maintenance of the system is a further advantage. All components are designed to be easily accessible and thus enable regular and efficient maintenance.
Fast implementation and close coordination
Having been commissioned by Moser fish farm in late summer 2023, work began on the customised solution, which involved close cooperation between BOGE and INMATEC. This was the first joint project between the two companies and it soon became apparent that the expertise of the partners was perfectly matched. The compressor unit including conditioning system was manufactured at the BOGE plant in Bielefeld, while the oxygen generator was produced by INMATEC in Herrsching am Ammersee. Once the components had been finalised, the complete system was delivered to Zillertal, where it was assembled by a BOGE employee in close co-operation with the customer. A regional fitter installed the electrical system and the piping. Due to the ongoing construction, the system was finally commissioned at the beginning of 2024, after the oxygen generator had been precisely customised to the needs of the fish farm.
With the continuous oxygen supply and the efficient compressed air system, Moser fish farm has obtained a customised, sophisticated solution that offers maximum reliability and efficiency. The system has already paid for itself in its third year of operation. The fish farm is seeing clear financial benefits from saving on external oxygen deliveries, less downtime and improved fish growth. “The precise oxygen supply in real time, combined with high energy efficiency, has helped us reduce running costs while creating a healthy environment for the fish,” explains Franz Josef Brindlinger. "The system responds immediately to fluctuations and thus ensures stable conditions, which are crucial for the growth of the fish."
Expert advice and impressive technology
"The collaboration with BOGE and INMATEC went smoothly. We were impressed by the expert technical advice and the punctual and professional commissioning of the system”, says Franz Josef Brindlinger. "We have found a partner who not only offers an optimal technical solution, but also enables reliable and efficient operation." They particularly valued the high level of willingness to customise the system to the specific requirements on site. The combination of high-quality technology, ease of use and reliable operation has hugely impressed the company.
