Reduction in dimensions of the Alfa Laval PureSOx U - a design reduces weight and increase flexibility considerably – height reduced by 26% in jet section and 17% in absorber section (photo: Alfa Laval)
The Alfa Laval PureSOx scrubber is available in a U-design with greatly reduced dimensions. The improvements, which further increase the U-design’s flexibility, were announced around the same time as a date for decision on the 2020 global fuel sulphur cap.
“We have a strategy of continuous development for the Alfa Laval PureSOx platform,” says René Diks, Manager Marketing & Sales, Exhaust Gas Cleaning at Alfa Laval. “We launched our inline I-design in December 2015, and we are pleased to follow it so soon with significant advances in our U-design.”
The PureSOx U-design, which is used on the majority of vessels, is a U-shaped configuration where the jet and absorber sections are separated by a natural water trap. In the updated version, available from 1 May, the exhaust gas flow through the scrubber has been heavily optimised. This allows a dramatic reduction in scrubber height – 26% in the jet section and 17% in the absorber section – as well as a reduction in weight.
A key factor in achieving the reductions was the minimisation of back pressure, which has been done entirely without exhaust gas fans. “Avoiding additional equipment high up in the funnel is advantageous for maintenance and stability,” says Diks. “All advances in the PureSOx U-design, including the reduced back pressure, have been made by working with the exhaust gas flow itself.”
The reduction in size and weight adds to the advantages of the PureSOx U-design, which include the natural water trap, simple connection to multiple inlets and easy switching between open-loop and closed-loop modes. A smaller scrubber facilitates placement and reduces installation costs, while a lighter scrubber reduces the impact on vessel stability. In some cases, the smaller U-design may also be placed lower in the ship, which will have further stability benefits.
“The improvements make it even clearer that the choice of U-design or inline I-design is not specific to vessel type,” says Diks. “A scrubber should be customised for the vessel it serves, and the new U-design makes the PureSOx customisation process more flexible.”