In the farm's recirculation system, the oxygen content in all tanks must be constant and precisely controllable – 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 generated for oxygen production in the compressor must have low moisture content so as not to cause corrosion in the system or allow bacteria growth or mold formation. The residual oil content must also be very low. These requirements called for a solution that works precisely with the existing control technology and is also capable of responding automatically and quickly to fluctuations, even during high load peaks. Another important criterion was the compactness of the system, as the available technical rooms were limited. The solution had to be space-saving and low-maintenance in order to ensure long-term efficient operation and reduce maintenance costs to a minimum. The aim was to create a system that would meet the requirements for precision, reliability, and energy efficiency all at once. In BOGE, Fischzucht Moser found a suitable premium supplier that could ensure both the compressed air supply and oxygen generation with systems from INMATEC, the leading manufacturer of nitrogen and oxygen generators, which has been part of the BOGE family since August 2023.
The compressed air system used by BOGE consists of a frequency-controlled C15-2LF screw compressor with a rated power of 15 kW. To ensure consistent compressed air quality in accordance with ISO 8573-1, the system has been equipped with a treatment unit. A 500-liter compressed air tank provides the necessary buffering, while a DT 26 refrigerated compressed air dryer with pre-filter prevents condensation and corrosion. An activated carbon absorber with microfiltration ensures high air purity to prevent contamination in the system. The INMATEC PO 150 oxygen generator is used for the oxygen supply, offering a capacity of 7.8 Nm³/h with a purity of 90%. Based on the principle of pressure swing adsorption (PSA), compressed air is passed through various filters to remove 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 allowing oxygen molecules to pass through. The oxygen produced in this way is fed into a 250-liter tank and fed directly into the tanks of the recirculation system via a pipe system with finely adjustable valves. An important aspect is the automation of oxygen dosing: 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 must be adjusted accordingly. “Optimal 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. “Below 6.5 mg/l, stress reactions begin – therefore, continuous monitoring and automatic adjustment are essential.”
Following the order placed by Fischzucht Moser in late summer 2023, work began on the customized solution, which required close cooperation between BOGE and INMATEC. This was the first joint project between the two companies, and it quickly became apparent that the partners' expertise was perfectly matched. The compressor system with treatment was manufactured at the BOGE plant in Bielefeld, while the oxygen generator was produced by INMATEC in Herrsching am Ammersee. Once the components were complete, the entire system was delivered to the Zillertal valley. There, it was assembled by a BOGE employee in close cooperation with the customer. A local installer carried out the electrical and piping installation. Due to the ongoing construction progress, the system was finally commissioned at the beginning of 2024, after the oxygen generator had been precisely adjusted to the needs of the fish farm.
With a continuous supply of oxygen and efficient compressed air, Moser Fish Farm has received a customized, technically sophisticated solution that offers maximum reliability and efficiency. The system has already paid for itself in its third year of operation. The fish farm benefits from a clear economic improvement thanks to savings on external oxygen deliveries, a reduction in failures, and improved fish growth. “Precise oxygen supply in real time, combined with high energy efficiency, has helped us reduce operating costs while creating a healthy environment for the fish,” explains Franz Josef Brindlinger. “The system responds immediately to fluctuations, ensuring stable conditions that are crucial for fish growth.”
