Aquaculture Air Products and Solutions February 2022

Exploring the importance of reliable and efficient low-pressure blowers to automated fish feeding systems for aquaculture

As automated fish feeding becomes more sophisticated, so too do the demands for ultra-reliable, efficient and low-maintenance blower systems. In this ‘Know How’ blog post, we look at what role low pressure / compressed air plays in pneumatic fish feeding systems, the benefits of automated fish feeding, plus how AI and digital transformation are changing the capabilities once more.

As aquaculture has become more intensive and farms have grown in size, the industry has had to find new solutions to traditional methods, such as how valuable fish stocks are fed. Traditionally done by hand, this method had a number of drawbacks. Manually feeding fish day in and day out can be a very labour-intensive job - and a particularly high-risk job for the workers depending on what the conditions are like on any given day. And, as farms became much bigger, this also meant more fish to feed, monitor and manage. The solution was the development and implementation of automated fish feeding.

air in aquaculture

Pictured above - Automated pneumatic fish feeding showing feed being equally distributed out into a sea pen with the help of a rotor spreader.
(Image courtesy of AKVA Group)

Pneumatic Fish Feeding - The benefits of using blowers to generate transport air

Automated fish feeding has been around now for many decades. The real breakthrough initially came with the development of a pneumatic feeding system which many believe revolutionised the salmon industry.

Used widely for salmon farming in sea pens, a pneumatic feeding system starts with a quality blower* which generates low-pressure compressed air. Feed is then transferred from a silo via a doser into the airflow. The air then transports the feed through a revolver selector valve. With minimum pressure drop, here distributor pipes rotate around an axis and connect one single feeding pipe with multiple feeding pipes. This then guides the feed to the selected pens. Feed is then equally distributed with the help of a rotor spreader.

This is a gentle method that creates little damage to the feed (pellet breakage) and compared to other systems like hydraulic feeding it is also a clean process. Most importantly it has proven to be an extremely reliable system.

Another big advantage of pneumatic feeding systems is the fact that it makes it possible to distribute much more feed per day than what could be achieved manually. This is especially important for large farms as they get close to harvest because as the biomass of the fish grows - so does the quantity of feed required. In salmon farming for example the amount of feed the fish require at the initial stage compared to when they are almost full-grown and ready to harvest, can be around six times higher. Feed can also be spread equally over a larger diameter with a pneumatic feeding system. This ensures that all fish have access to feed - not just the dominant ones.

As an additional and valuable benefit, by utilising an automatic feed system, you remove the dangers faced in rough conditions of manual fish feeding - which may also be near impossible in remote locations. A number of developments over recent times have made pneumatic feeding systems an even more efficient process, for example the use of camera systems in combination with automatic feed systems.

Here a person in the control room could determine when and how much to feed the fish by being able to detect how much the fish had been eating and stop feeding when no response was shown by the fish. This not only saved money by reducing if not eliminating overfeeding but reduced waste too (in terms of reducing the amount of unused feed in the ecosystem) - and an entire farm could be fed from the barge by one skilled worker bringing costs down even further.

Sensors then pushed this development along even further which could track for example the oxygen content of the water and the water temperature. When oxygen is low or temperatures are high, the feeding can be lowered or stopped so that the possible losses are minimised and fish welfare can be increased even in less optimal conditions.

Compressed air in aquaculture

Pictured above - Automated pneumatic fish feeding showing feed being equally distributed out into a sea pen with the help of a rotor spreader.
(Image courtesy of AKVA Group)

The Next Frontier - Digital transformation and AI bring a wealth of new benefits

AI and the availability of internet access in remote areas is now pushing the boundaries even further. It is now possible for the automated feeding of numerous sites to be controlled and managed from one centralised control room that can be located anywhere in the world! Here the AI system can differentiate between faeces and feed, and therefore take the decision itself as to when to feed and when to stop.

Furthermore, these new cameras are also capable of measuring the fish and calculating the weight - they can even detect sea lice so that actions can be taken without delay. This makes it possible to have a much better overview of the stock, improving fish size and quality.

air in aquaculture

Pictured above - It is now possible for the automated feeding of numerous sites to be controlled and managed from one centralised control room that can be located anywhere in the world! (Image courtesy of AKVA Group)

Conclusion

Reliable and efficient blower system is essential. So too is operating a blower system that requires minimal service - especially when you are talking about serving sea pens in remote locations. Selecting a quality blower that therefore satisfies all of these criteria, will contribute significantly to the smooth running of an automated pneumatic feeding system.

*Blowers can also be found in operation on the specialist feed boats and supply vessels which deliver the feed to the farms. Low pressure compressed air is used to convey 100t/h of feed into the feed barges. From here the feed is dispensed into silos, where the automated fish feeding process begins.


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Specialist Aquaculture Solutions from Kerr Compressor Engineers & KAESER

Compressed air and fluid power specialists in Scotland for over 40 years, Kerr is the UK's no.1 Authorised Distributor of KAESER KOMPRESSOREN / HPC compressed air systems and an experienced supplier to the Aquaculture industry throughout Scotland.

KAESER Compressors developed the CB 131 C Rotary Blower to meet the special requirements that automated fish feeding systems demanded. With thousands of these blowers currently in operation on feeding barges around the globe - if you are looking for a reliable and efficient blower solution that has been specifically designed with automated fish feeding in mind, then contact our specialist engineers today on 0800 008 6588 - web.enquiry@kerrcompressors.co.uk for more information and expert assistance.

Our reliable, energy efficient KAESER products are specifically designed and built to provide maximum durability in Aquaculture environments and ensure maximum process reliability to minimise the risk of downtime.

Read more on our Aquaculture Applications & Solutions page

Source & Credits: Author: Adrian Feiler, KAESER Business Development Manager – Aquaculture
Many thanks to our colleagues at KAESER - Australia for kindly allowing us to repurpose and share this blog.
Images: The photos in the above blog post are provided courtesy of AKVA Group

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