For many shipowners today, UV technology is the preferred choice for ballast water treatment – even for large ballast water flows
For many shipowners today, UV technology is the preferred choice for ballast water treatment – even for large ballast water flows. Not only is UV treatment simple and chemical-free, it poses no risk of corrosion to the ballast water tanks, so offers clear advantages over electrochlorination.
Nonetheless, all treatment systems need care. Key components – whether the TRO sensors of electrochlorination systems or the lamp sleeves and UVI sensors of UV systems – are at risk of scaling and fouling from exposure to seawater.
In a UV ballast water treatment system, the quartz sleeves protect the UV lamps in the reactor, while the UVI sensors measure the amount of UV light that passes through the seawater. If fouling or scaling occurs on either of these components, it can block the transmission of light. Thus, cleaning is necessary to safeguard compliance.
If the crew does the cleaning manually, it will involve both time and risk. A UV reactor may contain up to 50 lamp sleeves, which may be damaged, broken or poorly reinstalled. The labour involved, along with replacements due to a shorter sleeve lifespan, can lead to significant cost.
If mechanical wipers are used, automation removes the risk of human error. However, the wipers themselves have parts that will wear and break. Likewise, sand or grit can work their way under the wipers, which may scratch the sleeves and degrade the transmission of light. So, again, the costs are potentially high.
With these facts in mind, automated cleaning-in-place (or CIP) is the best cleaning solution for UV treatment systems. In Alfa Laval PureBallast 3, for example, a cleaning-in-place unit runs after each ballasting and deballasting cycle. This unit fills each UV reactor with a gentle cleaning fluid, which is made from biodegradable citric acid and is safe to drain overboard. After cleaning, the reactor is filled with fresh water until needed again.
Cleaning-in-place washes the whole UV reactor, rather than just the sleeves and sensors, fully protecting performance and energy efficiency. Moreover, it poses no risk to the ballast water treatment system, since it involves no chemicals, manual operations or mechanical parts.
Cleaning-in-place is a simple, safe and cost-effective way to get consistent treatment performance over the lifetime of a UV ballast water treatment system.
To see a film about cleaning-in-place and to learn more about how it safeguards Alfa Laval PureBallast 3, visit www.alfalaval.com/pureballast