Hybrid loop scrubber system


The hybrid loop system can run in both Open and Closed loop mode. The process water is either re-circulated or directly discharged back to sea. Switching between open and closed mode is done by using remotely controlled valves.

Hybrid loop systems are primarily used for vessels that operate mainly at open sea, but also considerably in ports and sailing areas where overboard discharge is prohibited.

Working principle

1. Exhaust gasses enter via the bottom side of the scrubber tower
2. Seawater is inserted at the top of the scrubber through spraying nozzles
3. This results in an equally divided spray pattern throughout the scrubber
4. Sulphur particles in the exhaust gas attach to the water droplets under the right temperature and process conditions
5. Cleaned exhaust gas leaves via the top of the scrubber tower

When operating in Open loop mode

6. The seawater leaves* via the bottom and is discharged overboard

When operating in Closed loop mode

6. Process water is led to the circulation tank
7. NaOH is added to the process water to neutralize acidity
8. Cleaned process water is pumped upwards again to the top
9. Polluted water is drained and led through a separator
10. Solids and oil are removed from the polluted water forming sludge
11. Sludge is pumped to the sludge storage tank on the ship

We were intrigued by the simplicity of the VDL AEC scrubbing system.
Their technology works without filters.
There is no pollution on the deck, no filters to clean and no maintenance.
After testing the VDL AEC Maritime closed loop scrubber on the Schleswig-Holstein
we were so convinced, we ordered scrubbing systems for three more vessels.

Fini Alsted Hansen, Technical Superintendent Fleet Management at Scandlines.