Electrochlorination Using Anti Biofouling Titanium Electrodes
A typical modern electrochlorination plant is a self-contained unit usually mounted on a steel skid ready for installation in an engine room.
It consists of a plate electrolyzer, with the main unit containing the anode and cathode plate titanium electrodes. The anode electrodes are coated with a catalyst containing mixed metal oxides, essential for the production of chlorine by hydrolysis.
The electrical power to the titanium electrodes is controlled by electrical panels, AC/DC transformer/rectifiers, and current regulators. The mechanical equipment includes metering and injection pumps, sampling elements, piping, valves, and the hypochlorite storage vessel.
I have illustrated these components in a sketch of the unit in the image section at the end of the article.
In operation, the electrochlorinator cell is supplied with seawater from the engine sea water cooling system that passes through the titanium anode and cathode electrodes which have a DC current supplied. This promotes the action of electrolysis of the sodium chloride contained in seawater, forming hypochlorous ions through hydrolysis.
These hypochlorous ions react with the bromides that are also contained in seawater to produce hypochlorite. This is then injected into the sea water cooling water pumps shipside seawater suction chest using a metering pump, which can be adjusted to alter the regular or intermittent dosing of the seawater intake.
On the ships cooling water discharge pipe, a small bore bleed-off pipe supplies the electrochlorinators skid with sea water which is constantly monitored, and the dose of hypochlorite adjusted automatically as required.
1. cathelco - electrochlorination of seawater
2. c-a-m - descriptions and illustrations of electrochlorination units