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Pure products and energy advantages aboard Norwegian Breakaway
4/10/2013 |
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In April 2013, the first of two remarkable cruise ships will be delivered to Norwegian Cruise Line from Meyer Werft in Germany. The vessels are notable not only for their size, but also for the fact that Alfa Laval's new PureDry heads up an extensive range of environmental and energy-efficient equipment on board.
With New York as its home port, Norwegian Breakaway will be the first of Norwegian's new Breakaway Class vessels. Together with its sister ship Norwegian Getaway, slated for delivery in January 2014, Norwegian Breakaway will combine all the best from Norwegian's existing ships with breathtaking architecture and new dining and entertainment concepts, as well as innovative technologies.
An unprecedented number of those technologies, including the PureDry waste fuel recovery system, have been delivered by Alfa Laval. Together, they constitute the broadest order Norwegian has ever placed with a single marine equipment supplier.
A record-breaking cruise ship
Norwegian Breakaway has drawn the attention of both cruise operators and the marine industry at large ever since its first steel was cut at the Meyer Werft shipyard in Papenburg, Germany. Able to house 4000 passengers in 2014 staterooms and suites, the vessel is 324 m long and 146,600 GT in size. This makes it the largest cruise ship ever built in Germany.
The vessel will also be the largest cruise ship to sail from New York City, where it will depart from the New York Passenger Ship Terminal in Manhattan. Following inaugural celebrations upon its arrival in New York, it will begin an itinerary of seven-day cruises, bound either for Bermuda or for Florida and the Bahamas depending on the time of year.
A groundbreaking installation - Alfa Laval's PureDry
Norwegian Breakaway will lead in areas other than size, however. For example, it will be the first cruise ship to take advantage of the new MARPOL rule MEPC.1/Circ.642. Under the new legislation, it is permitted to recover and re-use the HFO fraction of waste oil as fuel for the diesel engines.
"We're using Alfa Laval's new waste oil separator, PureDry, which we have high hopes for," says Christer Karlsson, Vice President of Newbuilding for Norwegian Cruise Line. "Instead of burning or landing our sludge, we can take care of it in a much better way and even put some of it back in the fuel tanks."
PureDry makes this possible through an unconventional approach to high-speed separation. Although technically a centrifugal disc-stack separator, Pure Dry has only two moving parts: the outer bowl and a separator insert, which rotate at slightly different speeds. There is no bowl aperture or sensitive hydraulic system to facilitate discharge. Instead, a patented, spiral-shaped device called the XCavator transports the separated solids to the base of the machine, where they exit into a container below.
A win for Norwegian as well as the environment
As its name suggests, PureDry requires no process water and leaves only non-pumpable ?super-dry' solids that can be landed as dry waste. Waste oil volumes are thus reduced by 99%, leaving around 5-15 kg per day of solids for disposal. The separated water, now with an oil content of less than 1000 ppm, is pumped to the bilge water tank as part of an integrated waste oil and bilge water handling system.
But the more interesting fraction from a ship operator perspective is the HFO recovered in the process, which can represent up to 2% of a vessel's total fuel consumption. "The environmental savings is combined with a financial savings," says Karlsson. "We expect PureDry to save us EUR 100,000 in Norwegian Breakaway's first year. So even if we're the first cruise operator to implement PureDry, Norwegian didn't hesitate."
Stig Björklund, Norwegian Team Leader Hull and Machinery, concurs. "It was very easy for us to get PureDry through the decision process. It's a huge gain if you can get so much fuel back, and recovering fuel is a very important driver."
Designing with PureDry in mind
In order for waste oil recovery to work, the traditional single waste oil tank has to be divided into one tank for fuel oil and one tank for lube oil. On Norwegian Breakaway, this was done in the design stage in anticipation that PureDry would be available.
"We came to the shipyard with the intent of purchasing PureDry, and with separate lines for lube and waste oil sludge in our specification," says Björklund. "I knew that PureDry existed, because I have former colleagues on the Silja Symphony, where the there is a test installation installed."
"In fact we conducted a visit aboard the Silja Symphony, where we saw the PureDry test unit in operation," adds Karlsson. "And of course we talked to the guys on board, who are people you can really trust. They said that it worked really well, and we could see that with our own eyes. We could actually see the high rate of oil return."
Karlsson continues, "The two-line waste oil system was incorporated into Norwegian Breakaway at the design stage because we were so confident that we wanted to get this product in."
Two sides to the coin: environment and energy efficiency
In some ways, PureDry is representative of the entire range of Alfa Laval products comprised in Norwegian's order for Norwegian Breakaway. Like PureDry, the order provides environmental protection and energy efficiency in equal measure.
"Our target at Norwegian is of course zero pollution, as far as we can possibly reach it," says Karlsson. "Obviously we still need to run the engine, but that's the only significant source of environmental impact. We land our ash, we work with the most environmentally friendly oils possible and we have environmental officers on board. And we also employ waste heat recovery systems. There's a greener thinking all over today."
As for energy efficiency, this is an area Karlsson sees as growing in importance. "Up to now, energy use has been part of our overall environmental policy," he says. "But with coming regulations such as the Energy Efficiency Design Index, it's becoming a clearer component."
With the equipment Norwegian Breakaway has on board, it will clear EEDI demands by a very substantial margin.
Pure products on board
In addition to PureDry, the environmental scope of the Alfa Laval delivery includes PureBilge, which was the first bilge water treatment system to pass the new, more stringent DNV 5 ppm type approval process. Providing cleaning performance in real-life conditions of 0-5 ppm oil content without chemicals, adsorption filters or membranes, PureBilge will be used in conjunction with PureDry as part of Norwegian Breakaway's integrated waste oil and bilge water handling system.
Also aboard Norwegian Breakaway will be PureBallast, Alfa Laval's chemical-free ballast water treatment system. "This is the first of our newbuilds to have PureBallast on board and the first purpose-built ship with ballast water treatment in our fleet," says Karlsson, who stresses the importance of a trusted supplier in this new application. "We looked at several ballast water treatment systems, but our thinking was that Alfa Laval is there after delivery as well. That's important to us. If there are any issues, we know they'll be sorted out."
Energy savings vessel-wide
As for energy efficiency, the new possibility of recovering fuel oil puts PureDry in the spotlight. But the Alfa Laval delivery comprises other tried-and-true products that also contribute to Norwegian Breakaway's energy profile.
Among these are high-speed separators with Alcap technology, as well as two Aalborg OM-TCi boilers, whose optimized thermal design ensures lower fuel consumption and a total efficiency of 89-92% depending on boiler load conditions. After Norwegian Breakaway's main engines, four Aalborg XW waste heat recovery boilers will recover heat energy for use in steam production.
Waste heat will also be involved in the generation of fresh water, which is a critical application for any cruise ship. Norwegian Breakaway will employ the Alfa Laval Multi-Effect Plate (MEP) evaporator, whose patented plate design and thin-film process yields both high distillate purity and high thermal efficiency. Typical electrical energy consumption for the MEP evaporator lies between 1.3 and 3.0 kWh/m3, thanks to an optimized pump configuration and the application of a frequency-controlled motor on the sea water pump.
Björklund is also keen to emphasize the maintenance aspects of the MEP evaporator, which only needs to be cleaned once per year with the help of non-toxic agents. "We've discussed freshwater generation a lot with Marine Operations and are convinced that the maintenance cost will be lower, just like the energy consumption," he says.
No doubts about Alfa Laval capabilities
Given that Alfa Laval's delivery to Norwegian Breakaway involves so much equipment and so many key applications, one might expect a degree of anxiety on the part of Norwegian Cruise Line. "This is quite a big order, and to my knowledge we haven't placed an order this big with a single supplier before," Karlsson admits. Asked if he feels concerned entrusting so much to a single supplier, however, he answers that he feels confident.
"All of these products were on the makers list and proposed to us by the shipyard," Karlsson explains. "We had no hesitations. Alfa Laval is not exactly a backyard company, and we have previous experience of their high-speed separators and Aalborg boilers. This is a long-term business relationship."
Speaking from the standpoint of technical integration, Björklund can only agree. "We have very good experience of working with Alfa Laval from a technical perspective," he says. "In the equipment we discuss with the yard and eventually choose, we always aim for the highest quality. And Alfa Laval is a very well-known maker."
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