The RayClean system from DESMI Ocean Guard A/S is a new supplement to the company’s ballast water treatment system (BWTS) product portfolio which already includes the OxyClean system. Both systems are based on mechanical filtration and UV irradiation with low-pressure lamps, but whereas a single OxyClean UV-unit can treat 100 m³/h of ballast water, the RayClean UV units can treat 300 m³/h. This makes the RayClean system more cost competitive at higher flow-rates, DESMI said.
The RayClean system sets new standards for the industry with regards to treatment performance and power consumption. When developing the system the goal was to design a unit capable of coping with challenging water conditions and at the same time reduce power consumption to the lowest level in the class. This has been achieved by use of highly energy-efficient low-pressure UV lamps combined with lamp dimming in clear water (high UV-T). By monitoring the UV intensity inside each UV-unit the lamps can be dimmed when the intensity is higher than the critical level. This results in a constantly applied UV dose independent of the UV-T of the water to be treated.
In typical water conditions with UV-T higher than 0.55, the flow rate through each UV-Unit is 300 m³/h, whereas energy consumption lies within the range from 5.0 to 8.0 kWh per 100 metric tons treated water, or 15.0 to 24.0 kW power consumption for a 300 m³/h system.
According to DESMI, type approval testing has demonstrated that the RayClean system can treat water with UV-Transmission as low as 0.33 in challenging conditions like very muddy water and pure fresh water, and still satisfy both the IMO and U.S. Coast Guard discharge standards.
RayClean operates fully automatically. The automation system will interface with the existing systems on board and the master control panel, consisting of a 15 inch color graphic touch screen, can be placed anywhere on the vessel.
DESMI Ocean Guard has completed all the landbased testing required under both the IMO and U.S. Coast Guard protocols. Five tests in high salinity water, five tests in brackish water and five tests in fresh water have been completed. All testing have been done at DHI in Denmark under the supervision of DNV. DNV has been appointed as Independent Laboratory by the U.S. Coast Guard and DHI has been approved as their subcontractor. This means that all the testing conducted with the RayClean system has been done in accordance with both IMO and USCG requirements.
Shipboard testing is progressing and is expected to be finalized early 2014.