STOR MARINE SERVICES
Unpurified water-cooling and firewater systems, are critically dependent on freedom from blockages due to bio-fouling. For example marine fouling can take the form of growths ranging from fungi and bacteria to simple plants and animals adhering to the pipe walls as larvae before developing into adult forms which, if unchecked, can result in partial or complete blockage of the sea water piping.
Such fouling results in inefficient operation and expensive downtime and is directly responsible for enhanced corrosion of piping, heat-exchangers and other items of process plant because of impingement/erosion and pitting and crevice corrosion due to differential aeration.
Corrpro has a worldwide reputation as a leading manufacturer of equipment and systems for cathodic protection of industrial plant and pipelines and leads in the design and manufacture of protection equipment for the marine and offshore industries.
The Anfomatic® electrolytic anti-fouling system is well established for use in shipboard seawater circulating systems. The principal of electrolytic anti-fouling is also widely recognized for industrial and offshore applications by leading North Sea, Arabian Gulf and American operators. It offers an alternative to the high capital, operating and maintenance costs of chemical dosing and the toxicity and safety hazards associated with chlorine treatment. Anfomatic® anti-fouling offers significant advantages for raw or seawater pumping and circulating systems and has a wide range of applications such as:
The Anfomatic® system employs the well established impressed current method to selectively dissolve both copper and aluminium or soft iron based anodes. These anodes are arranged in a steel frame (e.g. a vessel's sea-chest) or placed in a reaction vessel.
They should be positioned as near as possible to the inlet to the intake structure. Alternatively, depending on the pump sizes, the anodes can be arranged in a cylindrical steel framework mounted coaxially in the stilling tube of the pump. The anode assembly is cabled back to a remote power control unit through junction boxes as appropriate.
The Anfomatic® system discharges cupric ions into the water. They prevent settlement of organisms and the development of fouling. Additionally, the dissolved aluminium forms a hydroxide 'floc', which is carried through the system. Aluminium ions are incorporated into surface films, modifying them into a stable and protective form, thus mitigating the corrosion process in ferrous sea water systems. Where non-ferrous material is used, soft iron anodes are specified to mitigate corrosion.
The concentration of copper required to prevent adhesion and growth of microorganisms is relatively minute (parts per billion). It is controlled by the output from the power unit, which can also be interlocked with the main pump controller. When the pumps are not operating the power unit will maintain a pre-calculated output necessary to maintain the lower levels of copper dosage required. When pumping commences, the controller will boost the dosage rate to levels commensurate with the water flow rate.
Features and benefits overview:
Fouling prevention and corrosion mitigation are combined in one installation.
WCS offers a complete design service for the Anfomatic® system and will supply all necessary equipment including anode assembly, cables, power unit, junction boxes and other accessories.
Experienced engineers are available to supervise the installation and commissioning of each system, which is usually straightforward enough to be handled by a site contractor.
Each Anfomatic® system can be custom designed and the following information is required to allow Marpo to tailor the equipment for the specific application.
Water analysis and conductivity, temperature range, fouling history.*
*Not necessary for installation on ships.
