The system is now approved for operation in all salinities, all sea temperatures, and for water with UV-transmission anywhere from 33% to 100%.
DNV GV, a global ship and offshore classification society issued a type approval certificate, which includes approval according to both the IMO Ballast Water Management Convention and the DNV. This is the first time a ballast water treatment system has been tested fully according to both IMO and US Coast Guard requirements.
To pass the tests, the RayClean system underwent 15 landbased tests, five in each salinity, and five shipboard tests as per US Coast Guard test requirements. IMO requires 10 landbased tests in two salinities, and three shipboard tests.
Coast Guard approval
During landbased testing anff “operation and maintenance” test involving the treatment of 10,000 tonnes of ballast water was performed, and the electrical equipment in the system also went through more demanding vibration tests than required by IMO. This puts the RayClean system in a good position for US Coast Guard type approval, which no system has been awarded yet, according to DESMI.
The RayClean system is based on filtration and UV treatment with low pressure UV lamps.
“When we started the development and approval of the RayClean system three years ago, it was clear to us that not only should the system be approved to work in all salinity regimes, we also wanted a system that would be able to treat water in compliance with the IMO and USCG discharge requirements everywhere in the world,” said Rasmus Folsø, CEO of DESMI Ocean Guard. ”And this is where the UV-Transmission limitation comes into the picture.
“We experience that this issue receives more and more attention from shipowners, because it could potentially cause big problems during operation of the vessel. If you operate a ballast water treatment system in water with a lower UV transmission than what the system is approved for, the system will generate an alarm, which will be stored in the log of the system. When arriving at, for example, a US port the authorities will require documentation regarding the ballast water you wish to discharge, and part of this documentation is the ballast water treatment system log. If this shows an alarm for too low UV transmission, the ballast water has not been treated according to requirements and the shipowner may not be allowed to discharge the ballast water.”