Hulls keep clean in ‘the zone’
The antifouling zone system from Bright Spark is based on a very simple principle
Marinas could benefit from a couple of high-tech innovations. One of the more interesting is an antifouling zone that will keep boaters' hulls barnacle free.
This works through two electrodes (one anode and one cathode) that together form an electrolysis cell. A small cloud of copper-ions emerges from the electrodes that prevent the growth of barnacles, mussels and other micro organisms with hard shells.
The parabolic protection zone between the electrodes is about 20 metres (65ft) in length and approximately 8 metres (26ft) wide, depending on the placement of the electrodes and the conductivity of the water. In seawater there is higher conductivity and a greater protection zone then in fresh where the zone may only stretch 10 metres (33ft) long by 4 metres (13ft) wide. However, the electrodes can be used in combination with each other giving a broader antifouling zone.
Low flow use
It’s a good application for harbours with little flow. Most antifouling paint works if the water under the hull is moving substantially, while this anti-fouling system is effective in salt or brackish water with little current - 3 to 5 knots or less - as otherwise the copper ions get flushed away.
What is useful is that the system has NO influence on the cathode protection of any vessel, and likewise, it won’t affect the performance or consumption of zinc anodes. When the copper-ions have finished their work, they simply oxidise rather than polluting the environment.
This ‘zone’ system can work on 12V or 24VDC or 110-240V AC input, and requires little draw, so it might be possible to run it from a solar cell if there isn’t a power source readily available. Current consumption can be set from 600 mA/hr up to 1 Amp per hour for a single set: however, the voltage increases proportionally with the wearing down of the electrodes although there is an initial base level of only 2V DC.
The system requires little maintenance, which is a useful plus. It needs a bit of manual variation, as when water temperatures are higher (summer time) or there is a large current (like spring tides), power to the electrodes should be set at the highest level.
Apart from this, it’s only the electrodes that need replacement (an easy enough job), roughly once or twice a year.
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