Subsea Industries’ glass-flake, non-toxic hard coating Ecospeed has been chosen to protect the exhaust scrubber outlets of three newbuild container vessels building at a yard in Zhoushan, China.
A durable coating was required, with the ability to withstand the very high exhaust gas temperatures and the chemical pollutants encountered in this application. Scrubbers are intended to filter out oxides of sulphur and harmful hydrocarbons, soot, particulates, heavy metals and ashes to prevent pollution of the atmosphere. Some scrubbers, such as those fitted to these vessels, can also reduce the amount of nitrogen oxides and carbon gases.
However, according to Subsea Industries, some shipowners have experienced damaged pipework at the outlet end of the scrubber system due to the highly corrosive wash waters produced during the exhaust gas cleaning process.
Manuel Hof, Production Executive of Subsea Industries, said: “There have been some instances where unprotected pipework has completely corroded after just three years of scrubber operation. Shipowners and shipbuilders looking to install exhaust gas scrubbers must not overlook protecting internal pipework with an effective coating.
“Ecospeed is highly suitable as a protective coating for scrubber outlets and interior surfaces because it is highly resistant to chemicals and will last the lifetime of the ship. The nature of the process taking place inside the scrubber requires a coating with special qualities, which Ecospeed can deliver.
“Its proven durability means that no recoating will be required, cutting down on out-of-service time and thus saving the owner money in the long run. It is also highly resistant against a wide range of chemical products, which is one of the main reasons why Ecospeed is being increasingly selected for this kind of application.”
Ecospeed’s durability has been proven by the fact that classification society DNV GL awarded it the highest B1 classification following tests of its suitability as a ballast tank coating. B1 is the superior grade in a six-grade classification system.
Independent research has shown Ecospeed to be 100% toxin-free, with no adverse environmental effects resulting from its use or application, unlike other coatings which can contain biocides, copper or tin compounds.
Shipping is coming under increasingly tight environmental legislation. The need to reduce sulphur emissions requires ships to either use expensive low-sulphur fuel oils, or fit exhaust gas scrubbers to remove sulphur and other harmful compounds from the exhaust gases before they are vented to the atmosphere. Scrubbers allow ships to continue to use the lower-cost heavy fuel oils, even in tightly-regulated coastal areas, so they are increasingly being installed onboard vessels. To maintain the scrubbers at optimum efficiency, they need a durable, inert coating to prevent corrosion.
“Ecospeed fits in seamlessly with the environmental idea behind these systems,” said Hof.