As ship owners globally face the eventual mandate to install ballast water management technology onboard their ships – a refit which is touted as the most expensive equipment refit ever – Maritime Reporter & Engineering News in its February 2013 edition examines emerging Ballast Water Technologies for consideration.
In 2002 N.E.I. began development of a de-oxygenation ballast water treatment system – the Venturi Oxygen Stripping (VOS). In 2007, N.E.I. obtained the world’s first IMO Certification-Liberia.
Venturi Oxygen Stripping (VOS) is a physical process, which removes Dissolved Oxygen (DO) from the ballast water during intake only (no retreatment is required during discharge). VOS does not require any filtration or active substances, and does not require changing ballast pumps due to flow restrictions. VOS leverages a highly efficient Stripping Gas Generator (similar to an Inert Gas Generator) to produce a very low oxygen gas (Stripping Gas). This gas is introduced to the ballast water via a Venturi Injector (VI). The VI generates extreme cavitation/vacuum in-line, creating a bubble emulsion in the ballast water. Within ~10 seconds, more than 95% of the DO is stripped out of solution, and simply vented to atmosphere. Any species dependent upon oxygen is suffocated, treating many controlled species within an hour. However, the oxygen levels are high enough to prohibit anaerobic life. Many organisms are treated during the venturi phase of treatment itself (due to the sheering forces intrinsic to the cavitation process).
VOS is currently Type Approved with a Treatment Rated Capacity (TRC) of 6,800 cu. m./hr.
VOS equipment has been installed on Bulkers, Tankers, and Containerships. A total of 58 systems have been sold to date; specifically, 21 Installed (3 vessels not yet commissioned), 18 commissioned vessels,
www.NEI-marine.com
(As published in the February 2013 edition of Maritime Reporter & Engineering News - www.marinelink.com)