New offshore vessel to be fitted with Cathelco Ballast Water Treatment System
Cathelco is supplying a ballast water treatment (BWT) system for a new offshore vessel built by Eastern Shipbuilding Group Inc., for Harvey Gulf International Marine, LLC.
The Harvey Stone (Hull 234), a Rampage 6400 multi-purpose field support vessel (MPFSV), with a length of 64.8m and 18m beam, is due to be delivered in Q2 2016.
The Cathelco BWT system is based on a combination of filtration and UV technology and has a capacity of 150m3/hr.
Cathelco’s well established agent in New Orleans, Green Marine & Industrial Equipment Co.,Inc.,won the order.
The Cathelco system received IMO Type Approval in May 2014 and went on to gain AMS Acceptance from the U.S. Coast Guard a few months later.
As one of the new generation of BWT systems it can operate effectively in the most challenging water conditions.
The AMS approval recognizes that the system will continue to disinfect heavily silted seawater where UV light transmittance values are as low as 45 percent (75 percent being the value for normal seawater).
Cathelco’s BWT systems are available with capacities from 34m3/hr to 1,200m3/hr in a single unit. In order to maintain its effectiveness, the system automatically adjusts to different sea water qualities. Unlike some systems which simply measure turbidity (amount of suspended sediment), the Cathelco system uses a UVT sensor to measure UV light transmittance – the amount of UV radiation actually passing through the seawater. This is a far more reliable parameter for calculating the UV dose as well as ensuring that power is used economically. Another important factor is the use of stepless power control, again ensuring that power is used as economically as possible.
The space-saving UV chambers are some of the smallest on the market. Each unit is a twin chamber with only two lamps (100m3/hr per lamp) and is designed to make the sea water flow along one side and then the other – doubling UV exposure. In addition, the manifolds make the water flow in a helix, ensuring that the maximum surface area is exposed to the UV light source.
An innovative cleaning system using special cleaning balls is used to remove residue from the quartz sleeves and internal surfaces of the chamber. This means that the system does not use chemicals and there are no mechanical parts to scratch the surface of the sleeves.