Hamworthy Moss AS has won a major contract to supply 10 nitrogen generator systems for a series of 47,500 dwt chemical carriers being built for IRISL by Hyundai Mipo Dockyard in Korea. The 10 ships will be delivered between 2010 and 2012. A total value of more than US$11 million makes this one of the largest contracts ever signed by Hamworthy Moss.

The nitrogen generators will deliver 3,750 Nm3/h nitrogen at a purity of 95 per cent, and are the biggest systems ever delivered by Hamworthy Moss.

“Nitrogen generator systems have always been seen as a supplementary product to our combustion-based inert gas (IG) systems, and have been mainly used for inerting small volumes, such as flushing pipes,” says Geir Hellum, managing director of Hamworthy Moss AS. “This is now set to change as we are extending our portfolio to include nitrogen generators as ships’ main IG plants.”

Active in the marine market for nitrogen generators for almost 15 years, Hamworthy Moss has for some time dedicated significant resources to this product and market. “A new design has been developed, new suppliers have been brought in, components have been tested, better tools and understanding are being applied to put the quotations together, and plans for further improvements are in place,” Mr Hellum says. These developments are starting to bring results with the order intake for nitrogen generators steadily increasing over the past year.

“This highly contested order at one of the most important builders of chemical carriers is proof that the additional effort made in the development of this product is paying off, and that we now have a very competitive product, both technically and commercially. The combination of a technically advanced solution, a competitive price, and an extensive service and after-sales organisation all contributed to the decision by the owner and yard to go for a Hamworthy Moss system.”

Moss nitrogen generators use state-of-the-art membrane technology. Membranes separate gases by the principle of selective permeation across the membrane wall. Ambient air is compressed, rigorously filtered, and temperature controlled before entering one or more membrane modules, each containing thousands of hollow fibres. Within these fibres, the separation of air takes place producing nitrogen gas under pressure. The resulting nitrogen is dry and depleted of carbon dioxides.

The required number of membranes are assembled in cabinets or racks. A design based on handy modules means that the Moss nitrogen generator system offers valuable savings in space and installation costs both for newbuildings and for retrofitting on existing vessels.

“The unique Hamworthy Moss design is based on experience from thousands of  installations of inert gas systems of all kinds,” Mr Hellum says. The company delivered its first conventional inert gas systems in the 1960s, and the first nitrogen system in 1994. “High efficiency, low maintenance costs, safe and easy operation combined with minimum space requirements are important features of the Hamworthy Moss design.”