Anti-Fouling System- Chlorination
INTRODUCTION
This system is designed to prevent the adhesion of marine growths to the internal pipe line of ships through the chemical reaction of chlorine compounds which are produced through the electrolyzation of sea water.

First, the sea water taken out of the outlet of one of the common sea water pumps or the pump for exclusive use in MGPS is led into the Generating Chamber, in which the sea water is electrolyzed with specially designed electrodes. Then the sea water containing chlorine compounds is injected into scoop or sea chests through the nozzles to mix with the sea water sucked in from outside of the ship, thus preventing marine growths from adhering to the interior of the ship's sea water line including sea chest, piping and heat exchanger.
THEORY
The anti-fouling process is based on the electrolysis of part of the sodium chloride (NaCl) contained in sea water. The electrolysis is obtained by passing the sea water through a generating chamber containing electrode(Ti anode).
The chemical and electrochemical reactions which occur in the generating chamber are as follows;

1) at the anode free chlorine is formed
    2 Cl ⇔ Cl₂ + 2e-
2) at the cathode OH-ions are formed
    2 H2O + 2e- ⇔ 2 OH-+ H3
3) around the anode the OH- ions react with the Na+ ions and Cl2 to produce sodium hypochlorite
    2 NaOH + Cl₂ ⇔ NaOCl + NaCl + H2O
Alongside these principal reactions which bring about the production of sodium hypochlorite, secondary reactions occur due to the cations which are present in sea water such as calcium and magnesium, forming hydrates and carbonates.
The sodium hypochlorite solution leaving the generating chamber is piped to the chlorine injection points situated on the sea chests to be mixed with the incoming sea water flow. Then the chlorine-active contained in the solution oxidizes the organic substances found in sea water.

The adult organisms, for example mussels, are able to resist the effects of chlorine-active by closing themselves inside their shells. However unable to feed they will not settle in an environment where chlorine-active is present.
EFFECTS OF CHLORINE
Chlorine is a well known toxicant. It has been shown that 0.2 to 0.5 PPM of continuous chlorination will prevent all marine fouling in time. Higher than 0.5 PPM might produce the corrosion of the metallic piping, and other metallic Equipment.
A trace residual discharge will insure the killing of all fouling organisms in a sea water system when constant chlorination is employed. It should be emphasized that constant chlorination is the best method for safe and efficient fouling and bacteria control.
Typical Arrangement of  Piping Diagram
Typical Arrangement of Piping Diagram
SYSTEM COMPONENTS
1. Power Supply - This is a power converting device, transforming the Client supplied AC440 Volts, 60 Hz, Input power to
    a Low Voltage and High Current CONTROLLED DC Output power. This DC power is supplied to the Ti anodes,
    to produce the designed Sodium Hypochlorite Output.

2. Generating Chamber - Ti anodes arranged on the Chamber lid by flange mounting. So the entire seawater passes
    through Ti anodes.
Control Panel
INSTALLATION
Installation requirements are limited to adequate amounts of seawater, electrical power and space. Seawater should be available through a 2"(50A) nominal pipe at sufficient pressure and a discharge line 2"(50A), which leads to the point to be chlorinated. Seawater should be a salinity of approximately 20 to 40 ohm-cm which is the approximately consistency of sea or coastal salt water. The input lines may be of any suitable sea water resistant material, but the output lines should be of Saran-lined steel, PVC or other corrosion resistant material.
OPERATION
Chlorine Generator is designed for constant unattended operation. The Power Supply is of a constant current type, which will provide constant Chlorine Output under changing water conductivity; thus eliminating tidal or temperature induced variances. It is equipped with safety features, which will trip the Output circuits in case of malfunction.
MAINTENANCE AND SERVICE
There are service and maintenance procedures presented in each of our Manuals. However, the equipment has no moving parts and should require for little or no maintenance. The renewal of Ti anodes will be required periodically and can be accomplished with a minimum of down time if the procedures in this manual are followed.