The Alfa Laval PureSOx exhaust gas cleaning system is used for SOx abatement. The platform is now available with an inline I-design scrubber.
Alfa Laval PureSOx can be adapted to suit individual vessels and offers open-loop, closed-loop and hybrid arrangements. The inline scrubber makes it even easier to adapt.
Inline Scrubber
The inline scrubber design, or I-design, builds on the PureSOx technology. It provides an additional alternative for vessels with more complex structural needs, such as certain cruise ships and RoPax vessels.
An important consideration in creating an inline PureSOx scrubber was the water trap, which is not formed naturally as it is in the existing U-design. A key focus was eliminating the potential for water backflow, which is done by means of an internal water trap combined with overboard arrangements.
As with the U-design PureSOx scrubber, the I-design scrubber can be configured with multiple inlets. This reduces space needs and installation costs by allowing one scrubber to handle exhaust gas from multiple sources, including boilers as well as the main and auxiliary engines.
Reflux
A further alternative for inline PureSOx configurations is reflux. This option is especially attractive for cruise ships, RoPax vessels and other vessels that carry passengers, as it reduces the risk of dirty water droplets discolouring the ship’s deck. Reflux involves the creation of two separate loops: one for the jet and a second for the absorber. In the jet loop, clean water is evaporated by means of the waste heat in the exhaust gas. The vapour is then recondensed as clean water in the absorber loop.
As a result, the water in the absorber stage is significantly cleaner and the risk of deck discolouration is greatly reduced. Since the soot is concentrated in the initial jet stage, the water cleaning unit has a lighter burden as well.
Water Cleaning
The water cleaning unit is a vital component of any closed-loop or hybrid PureSOx system. When the scrubber is in closed-loop mode, the unit removes soot from the circulation water, thus protecting the scrubber and enabling compliant discharge of bleed-off.
The PureSOx water cleaning unit uses centrifugal separation, a technology that is unaffected by pitch and roll.
Picture: Alfa Laval PureSOx Hybrid Inline configuration (full picture below).
