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DESMI Ocean Guard RayClean
Ballast Water Treatment System

Proven effective in all water salinities with UV-T (UV-Transmission) as low as 0.33 which sets the industry benchmark.

- lowest energy consumption in class

RayCleanTM Ballast Water Treatment System is the leading system in the marine industry with unrivalled treatment performance and lowest energy consumption in class.

RayCleanTM is IMO and DNV type approved and has earned the Alternate Management System (AMS) acceptance by the US Coast Guard (USCG). The AMS acceptance covers all salinities ranging from freshwater to marine water, something that only eight out of 52 issued AMS acceptances have achieved to date. RayCleanTM has been proven capable of dealing with extremely dirty and unclear water – a wide UV transmission range that no other UV system on the market today is approved for.

RayCleanTM has been tested in accordance with both the IMO and USCG requirements and with DNV GL as Independent Lab appointed by USCG and all testing facilities have been approved by USCG.



The RayCleanTM system

Easy and fully automatic operation

RayCleanTM is a fully automatic process based on a PLC platform, which controls the valves, pumps, UV sensor, flow meters, pressure- and temperature sensors.

The operation of the system is made as simple as possible. The operator only has to start and stop the ballast and de-ballast operation and the remaining part of the operation is then fully automatic.
RayCleanTM can be started or stopped from the colour graphic Touch Screen on the Master Control Panel which can be integrated in an existing control system on board the vessel.

RayCleanTM is automatically optimizing the power consumption via dimming of the lamps and regulation of the flow in accordance with the characteristics of the water. During ballast and de-ballast operations the control system is logging the operation data and time-stamp the date before it is saved into a log file.



RayCleanTM has a self-cleaning filter in order to remove the vast majority of organisms larger than 50 micron.
During de-ballast the filter is used to ensure that organisms which are small or soft enough to pass the filter on uptake, and which have grown large enough to be stopped by the filter mesh at discharge, will be treated and rendered inactive.

The RayCleanTM filter system has a unique and patent pending way of recirculating the filter backflush stream on ballast water discharge.


The UV treatment takes place in units with a flow capacity of 300 m3/h. Each UV unit is equipped with 60 highly efficient low-pressure UV lamps. These lamps are roughly twice as energy efficient as the widely used medium pressure UV lamps, and as they work at much lower temperature they have superior lifetime and no issues with regard to fouling.

Constant online monitoring of the UV intensity inside each unit is used to dim the UV lamps in very clear water (high UV-Transmission) in order to save energy, and to reduce the flow through the unit in extremely unclear water (low UV-Transmission). This ensures a carefully dosed UV treatment at all times resulting in IMO and USCG compliance even in extremely challenging water conditions. All lamp dimming and flow control are fully automatic.


RayCleanTM consists of two types of control panels, a Master Control Panel and a number of UV Control Panels, one for each UV unit.
RayCleanTM is controlled by the PLC located in the Master Control Panel. The UV Control Panels are connected to the Master Control Panel via a Profinet Ring bus. The Master Control Panel has a 15” colour graphic touch screen (also called HMI). This is used for local control of the system, but as an option one or more HMI’s can be offered and integrated into the solution. RayClean can interface with the vessel’s Integrated Ship Automation System and/or Power Management System. This is can be made either as hardwired signals via a multicore cable and/or as MODBUS RTU communication.

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Types of system deliveries

Component delivery

Component Delivery

Skid mounted solution

Skid mounted Solution

Container solution

RayClean Container Solution

RayClean - lowest energy consumption in class

The low power consumption is achieved by use of highly energy efficient low-pressure UV lamps combined with lamp dimming in clear water (high UV-T) and flow reduction in very challenging and unclear water (low UV-T).

By monitoring the UV intensity inside each unit the lamps can be dimmed when the intensity is higher than the critical level, and the flow can be reduced when the intensity is lower than the critical level. This results in a constant applied UV dose independently of the UV-T of the water to be treated.

Under normal conditions where the UV-T is higher than 0,55 the flowrate per unit is 300 m3/h and the energy consumption of the entire system is around 8 kWh/100 m3 when lamps are not dimmed, and as low as 5 kWh/100 m3 when the lamps are dimmed as much as possible.

Capacity [m3/h] System Power
Consumption* Max. [kW]
System Power
Consumption* Min. [kW]
Weight [kg] Foot Print** [m2]
100 21 11 1425 5
200 21 11 1425 5
300 21 11 1675 5
400 42 22 2525 6
500 42 22 2975 6
600 42 22 2975 6
700 63 33 3825 8,5
800 63 33 4075 8,5
900 63 33 4075 8,5
1000 84 44 4925 10,5
1100 84 44 4925 10,5
1200 84 44 5375 10,5
1300 105 55 6175 11,5
1400 105 55 6175 11,5
1500 105 55 6175 11,5
1600 126 66 7525 12,5
1700 126 66 7525 12,5
1800 126 66 7525 12,5
1900 147 77 8325 14,5
2000 147 77 8875 14,5
2100 147 77 8325 14,5
2200 168 88 9725 16
2300 168 88 9725 16
2400 168 88 9725 16
2500 189 99 11075 17,5
2600 189 99 11075 17,5
2700 189 99 11075 17,5
2800 210 110 11975 19
2900 210 110 11975 19
3000 210 110 11975 19


Long lifetime on UV-lamps

Self-cleaning UV-unit

The RayCleanTM UV-lamps have a very long lifetime of approx. 12,000 hours.

This keeps your operational expenses down.

The UV-unit is a mechanical self-cleaning
unit without any use of chemicals.

This saves you a lot of maintenance time and no chemicals are needed on board for UV-unit cleaning.


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