MARCH 3, 2015 — Eight new 33,000 DWT chemical tankers under construction by an Asian shipbuilder will be fitted with Wärtsilä Aquarius UV Ballast Water Management Systems (BWMS) that have each been certified for explosion proof (EX) requirements. This means that the units can be installed in Zone 1 hazardous areas. It is an IMO requirement that the BWMS for ships having hazardous areas on board be EX-proof certified.
The contract, which was signed in January, is the first EX-system delivery since the Wärtsilä Aquarius UV system was granted EX-certification in spring 2014.
Each of the eight vessels will have two Wärtsilä Aquarius UV systems installed. The particulars of this design required a partnership approach with the shipyard in order to successfully integrate the BWMS into the hazardous area, with the addition of deepwell pumps already delivered.
Wärtsilä has taken a systems approach to the EX validation process and the complete Aquarius UV BWMS module, rather than just the electrical components, is EX-certified.
This approach improves accessibility, since the modular design allows some system components to be located outside the hazardous area, thereby increasing the availability and maintainability of the entire system.
"This first contract for our EX-certified BWMS represents yet another milestone contract for Wärtsilä," says Dr. Joe Thomas, Director, Ballast Water Management Systems, Wärtsilä Ship Power. "Knowing that the entire system module is explosion proof when installed within hazardous areas provides the peace of mind that alternative systems, where only the electrical components are certified, cannot,"
The Wärtsilä Aquarius UV BWMS uses a simple two stage process involving filtration and UV irradiation. During uptake, seawater is first passed through a 40 micron backwashing screen to remove particulate, sediment, zooplankton and phytoplankton. Disinfection of the filtered sea water is then carried out using medium pressure UV lamps, and controlled by the BWMS control system. Upon discharge, the filter is by-passed but the ballast water is again disinfected with UV treatment before safe discharge back into the sea.