Caution Against Comparing Drum Filters and Disc Filters
Turbulent waters at the mechanical filtration stage will lower the actual filtration result dramatically. To achieve excellent water quality, it is crucial to remove particles rather than crush them. The diagram illustrates how a gentle 80-micron filtration process can reduce particle load by 90 percent in a fish farm—significantly higher than the 68% achieved with a more turbulent particle treatment. This substantial difference is also seen by the fact that you need 15-micron filtration turbulent waters to match 80-micron to get the same filtration efficiency.
This create a substantial gab in water quality or investment, there is no good choice forward, if turbulent water treatment is ignored.
“Factors Influencing Suspended Solids Size in Aquaculture,” authored by Dr. Alexander Brinker and Dr. Roland Rösch from the Fisheries Research Station of Baden-Württemberg in 2004.
Minimal Turbulence with Drum Filters
Drum filters feature large openings at their entrance, allowing particles to flow gently into the filter and be captured by the filter cloth. Leading drum filter manufacturers include grid cells in the filter cloth, retaining particles until they are flushed away by the backwash system into a sludge tray. Due to the nature of drum filters and the gentle handling of particles within the cells, implementing intelligent control in the backwash system makes practical sense. Intelligent control significantly reduces backwash water consumption, activated only when the filter capacity is fully utilized.
High Turbulence with Disc Filters
Disc filters feature smaller entrances, causing particles to encounter edges at high flow velocities. Unlike the filter cloth in drum filters, the filter cloth in disc filters lacks cells. As particles slide around during rotation, they will break with such rough handling. The vertical backwash in disc filters, along with the smooth filter cloth without cells, makes it impossible to implement intelligent backwash control due to particles sliding on the cloth. The nature of the disc filter construction ultimately leads to particle grinding and, consequently, higher backwash water usage and rough handling of the fragile particles.
Efficient Particle Removal
Gently treatment of the particles can remove up to 3 times as many particles in RAS and outlets. It is simply sad to see re-introduction of disc filters, sedimentation and other filtrations systems, not having focus on this most critical issue in filtration, according to Kurt Carlsen, one of the co-founders of CM Aqua. With two decades of experience in the aquaculture industry, Carlsen’s statements carry weight.
Advantages of Drum Filters
Drum filters have a strong historical connection to aquaculture. Carlsen identifies various reasons for this association. Firstly, the filtration is optimal, proven over the past +30 years. Many fish farmers select drum filters due to maintenance considerations. They focus to keep the water quality optimal for their fish, prioritizing fish health, fish growth and welfare. Carlsen asserts that CM Aqua contribute to this goal with well-tested and efficient solutions.
Consistently Predictable Outcomes
Carlsen underlines that CM Aqua filters consistently maintain clean water with highly predictable results. He further highlights the significant benefit of minimal maintenance, reducing the labour hours required for facility upkeep. “Inspecting the filters is extremely straightforward due to their simple design,” Carlsen adds.
Diverse Range of Drum Filters
Drum filters are available in numerous variations within the HEX series. Carlsen showcases different series, each with distinct advantages. Whether you seek low noise levels, a mist-free environment, corrosion-resistant materials, space-saving designs, or reduced backwash water usage, CM Aqua has you covered.
- PE tops significantly reduce noise levels and prevent mist leakage during backwash
- X-series is entirely corrosion-free, with no metal components
- XL-series boasts exceptional capacity with a minimal footprint
- IC controls result in three times less backwash water consumption compared to standard drum filter control
- Direct Drive Gear Wheel (DDGW) employs high-tech polymer gear wheels that require no maintenance or lubrication apart from water
Introducing CM Aqua
- Headquarters in Copenhagen, Denmark
- Factory in Düsseldorf, Germany
- More than 40 employees
- Manufactures the world’s largest series-produced drum filter, capable of handling up to 10,000 m3/h