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E: info@ftleisure.co.uk
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Units 2-3 Bridgeside Business Centre
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Our ceramic membrane filtration system
Microfiltration is a physical filtration process where a contaminated fluid passes through a specific pore sized membrane to separate out microorganisms and suspended particles.
This is not a new form of filtration. Microfiltration has been used in many industries for over 30 years, including:
The most common material used for microfiltration system membranes is ceramic, or silicone carbide. This material is perfectly suited to the harsh and aggressive fluids passed through the membrane and can cope with extreme temperature ranges.
Microfiltration processes can remove particles from 0.1–10μm. In terms of swimming pools, most current filtration technology (eg media bed filtration) will filter between 5–10 μm.
Resources
Why change?
95% of public swimming pool filtration systems in the UK use media bed filtration to remove particulate. We have installed thousands of sand filters; this technology is simple and effective. It has been proven to achieve good quality pool water.
But media bed filters come with a few challenges, both in terms of design and operation.
Design challenges:
Operational challenges:
FT Leisure are swimming pool water treatment and filtration specialists; we know and understand the processes involved. However, we are not raw material manufacturers. We needed to team up with a specialist and we found the perfect partner: Saint-Gobain.
Saint-Gobain Ceramic Materials is an institution in the field of advanced engineered materials, providing unmatched expertise when it comes to ceramics technology. More specifically, Saint-Gobain Performance Ceramics & Refractories have been providing unique and high added value silicon carbide-based solutions for decades, including the first-to-market recrystallized silicon carbide (R-SiC) product. This outstanding ceramic forms the basis of their Crystar®️ filtration technology.
Crystar® FT is designed for liquid purity, security, and sustainability. The demands of filtration have changed dramatically over the years, as a growing global population forces industries to adopt more demanding processing capabilities to satisfy the needs of global sustainability efforts.
FT Leisure and Saint-Gobain have entered into a Bilaterally exclusive supply agreement for UK, Ireland and Channel Islands.
How it works - Filtering
Swimming pool water is pumped through each ceramic membrane at a rate of 15m3/hr. The honeycomb structure of the ceramic membrane has alternately plugged channels, thereby forcing the water through the porous material.
Each individual membrane has a filtration area of 11m2. That’s a filtration rate of less than1.4m3/m2/hr, compared to traditional media bed filtration which is typically 25m3/m2/hr.
The Crystar® FT Hiflo ceramic filters the pool water to 4μm. This is a guaranteed maximum pore size in the material, proven through mercury testing.
How it works - Washing
As particulate is collected in the pores, the pressure across the membrane increases. At a pre-set pressure or on a time-clock, a washing process will be automatically activated.
Washing takes place in pairs; whilst each pair is washed, the other remaining membranes continue to filter as normal. Once a wash is activated, the whole system will be washed.
The pair of membranes are drained down and high pressure air (4 bar) from compressor/receiver is used initially to dislodge particles. The particles are then flushed out to drain using a dedicated rinse pump (33.3ltrs/sec), using only 100litres of water at high velocity. This whole process typically occurs 4-6 times a day, depending on bathing loads and levels of pollution, whilst the pool remains open.
How it works - Cleaning
Over a period of time, the pressures in the system will build up due to greases, oils and biofilm, that the above washing process cannot remove.
An automatic CIP system therefore intermittently cleans the membranes, typically twice a month, depending on bathing loads and pollution levels. The whole system is shut down (out of hours) and 55˚C hot water is pumped around the membranes and Alkali detergent is dosed to achieve a high ph level (12). If scaling is an issue, a similar process can be carried out using an Acid chemical.
Once the CIP is complete, the system is refilled and filtering recommences, with no involvement required from the operator. The CIP process will return the membranes to their clean state.
Every person that uses a public swimming facility has different needs and expectations. Their motive may be relaxation, leisure, exercise, competitive sport, training, play or even therapy. All of these bathers however, have something in common; they all want to enjoy the experience.
Safe and clear water is a fundamental part of that experience. The Crystar® FT ceramic membranes have been laboratory tested and we can prove that FTMicron4® is achieving a much higher standard of pool water:
Advantages for the building
Accommodating swimming pool technology into a building is complex. Our systems interface with architecture, structural, civil, mechanical and electrical design services. Failure to integrate pool technology in the building design will inevitably result in operational issues and potentially lower quality pool water.
Microfiltration is easier to accommodate than media bed filtration:
Enhance your Pool!
If you have a swimming pool filtration system that’s reached the end of it’s serviceable life or if you are simply looking for opportunities to reduce your pool operating costs, FTMicron4® can be retrofitted to existing swimming pool systems.
Ideally the units are pre-fabricated, pre-tested and commissioned in our production facility, to reduce the amount of time on site. However, existing buildings often have restricted access openings, which make it challenging to get the system into the plantroom as a single unit. FTMicron4® can therefore be delivered in smaller components and assembled on site.
Older pool systems often have compromised pool water distribution systems, such as freeboard scum channels and cast iron pipework with reduced internal bores. We have retrofitted FTMicron4® to pools with these compromises and have achieved significantly enhanced pool water quality.
Advantages for the operator
Swimming pools are expensive to run. They consume a lot of absorbed power, water, heat and chemicals; this is a real challenge to the facility business plan. Microfiltration can help!
Advantages for the Operator
With traditional filtration systems, it’s the operator’s responsibility to ensure that the plant is running efficiently. There are limited monitoring systems available with media bed filtration. Maintenance is therefore generally scheduled around the facility resource, not necessarily around water quality parameters. FTMicron4® is a fully automated system, with remote monitoring services.
We will support you by monitoring the performance of your system and where necessary, we can make adjustments remotely. Washing and cleaning processes can be carefully managed to ensure they are proportional to your bathing loads. There is no daily, monthly or annual maintenance for you to carry out. We will carry out annual inspections of the mechanical elements of the system.
As with any new technology, which has been developed, researched and tested prior to launch, it carries a higher capital cost than existing technology. However, some of that increased capital cost is cancelled out by savings in construction. Whilst the overall capital cost is slightly higher than traditional media bed filtration, the operating costs are substantially less….for the life of the building.
Here’s some figures based on a typical 25m 6 lane pool:
(*includes additional drainage and construction costs)
Payback period only 1.3 years!
