Ecolcell MGPS System
1. What is electrochlorination?
Electrochlorination is an antifouling system designed to prevent both macro and micro marine fouling using an on-site antifouling solution – sodium hypochlorite (NaOCl).
2. Does chlorine not have detrimental effects on the environment?
No, for years chlorine has been used to purify water, in particular drinking water worldwide. It is recognised as one of the most effective and safest ways to purify water and this has been acknowledged by the WHO. Our MGPS system creates sodium hypochlorite directly from seawater and once it has been distributed to the seachests and into the seawater system it reverts to salt and water.
Further the concentrations of NaOCl used are in the range of 0.1 – 0.3 ppm. This concentration is the highest it reaches immediately upon release from the electrolysis group. By the time the water arrives at the seachests the concentration levels have decreased significantly and there is barely a trace of the antifouling agent to be found in the water.
3. What are the main differences between electrochlorination and use of copper/aluminium anodes?
Effectiveness: Electrochlorination is effective against macro AND micro marine fouling. Cu/Al anodes can only combat macro fouling.
1. Despite the initial (slightly) higher investment cost, electrochlorination saves the shipowner money in the long-run. The anode only needs to be replaced every 5-7 years as opposed to Cu/Al anodes that need to be replaced more regularly.
2. Antifouling agent, NaOCl, is created directly from seawater and requires no additional chemicals to be added.
Environmental Benefits: No harmful substances are released into the seawater.
Ecolcell MGPS System
1. What is an ICCP system?
Impressed Current Cathodic Protection (ICCP) system is designed to protect the hull of the ship from marine corrosion. It is designed to work in conjunction with the anti-corrosive paints to ensure that the submerged part of a vessel is completely protected.
These systems serve to extend the life of the vessel, the life of the protective paintwork thus extending the period between drydockings and provide cost-savings to shipowners. In general these systems are completely automatic in their operation.
2. What particular advantages do ACG's ICCP anodes offer over its competitors?
Our anodes are circular MMO recessed mounted and made of titanium. These anodes offer the following advantages to shipowners:
– Efficiency: Capable of maintaining a current density of 700-100 A/m2. They have an approximate consumption of 1 to 4 mg/A/yr.
– Size: Due to their high efficiency, titanium anodes are compact and light with an average size of 300 mm and weight 2 kgs.
– Installation & Maintenance: Their small size and weight makes them easy to transport, install and maintain. Replacement is easy and can be done by a single person.
– Lifetime: Titianium anodes can be designed to last over 20 years. They are small and recess mounted and therefore it is difficult to damage them.Fresh water use:Titanium anodes suffer no adverse effects when used in fresh and brackish water.
3. What is the dielectric shield?
The dielectric shield is used to to ensure that the current output from the anodes does not short near the anodes. In this way, ensures that the current reaches the furthermost parts of the hull.
4. What is the current density normally used by ACG?
For ships that have 3-5 year dry-docking intervals (under normal conditions) the protection generally required is between 35 and 45 mA/m2. One must consider that in general an ICCP system works at about 25% of its potential capacity during its lifetime therefore, we normally calculate the density of our system with 40 mA/m2 if nothing else is specified by the shipyard or shipowner.
5. How does our ICCP system operate in waters of diverse salinities?
When the vessel is sailing near the mouth of a river our titanium anodes work effectively to protect the hull from marine corrosion. In brackish water, even with a very low current (30 A) our system will work correctly.When the vessel is sailing in waters of low or zero salinity, it becomes difficult for the current to pass. In this case the ICCP system must be switched off or put on stand-by.