Caldharbour Marine, a manufacturer of ballast water treatment systems (BWTS) based on inert gas technology, has launched a new treatment process designed specially for bulk carriers.
The system uses the company’s existing inert gas based GLDTM treatment plant to meet the needs of[ds_preview] large bulk carriers, which often ship large volumes of ballast water in upper wing tanks and discharge it directly into the sea.
The Coldharbour solution is especially appropriate for bulk carriers because it addresses stability issues specific to the ship type, Andrew Marshall, Coldharbour Marine’s Chief Executive, explains. For example, bulkers sometimes load extra ‘heavy weather’ ballast water in cargo holds, which inevitably faces contamination by cargo residues. In-line systems would find this water hard to process and could be damaged by it. In this case, Coldharbour has developed a pipe circuit to allow ballast to be pumped from the various tanks through robust gas lift diffusion (GLD) units mounted in the machinery space – instead of in-tank, meaning that water can be returned to the tanks via multiple outlets to ensure that contents are stirred and treated.
»Big bulk carriers are usually deployed on long haul routes and lengthy ballast voyages can lead to significant organism regrowth. Ships fitted with in-line BWTS technologies cannot guarantee full compliance with discharge standards at the end of a long ballast voyage«, says Marshall.
Coldharbour’s system is not an in-line process and does not treat ballast water at uptake. Instead it is an in-voyage process, so there are no filters and no potential problems relating to flow rates, pressure drops, or power consumption during ballasting, he adds.
