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Buoy on board

Skimming oil from the water surface inside tanks

Barely 15 years ago, engineer Fredrik Pettersson had a simple idea to improve oil-water separation inside tanks. Until recently, few had heard of his Sludge Buoy. Now the invention is starting to gain wider recognition on the maritime market.

For many shipowners, oily waters are a persistent problem. The mixture of water, condensate, oil, and sludge takes up valuable space on board a ship, and tanks need to be drained and cleaned regularly. This task is made difficult by the tanks’ hard-to-reach location.

A feat of engineering

As an engineer on a cruise liner, Fredrik Pettersson was all too familiar with this issue. He wanted to create a solution: A skimmer that is easy to install and maintain and that can remain operable even under adverse sea conditions. Pettersson named the device “Sludge Buoy”, as its design was based on a buoy. Simply put, it is a skimmer that floats on the surface of the sludge and gathers oil before feeding it out through a pipe. The water left in the tank has a high degree of purity and is therefore easier to process downstream. The buoy itself is connected to the tank by means of a gimbal/cardan suspension, so it follows the motion of the ship.

The Sludge Buoy makes it possible to skim oil from water from a closed tank during a voyage. It separates the liquids right where they first appear, keeping the vessel’s systems clean. Also, because the oil pumped out contains a small amount of water, it can be incinerated without the need for further treatment. It is even pure enough to be sold on as a valuable substance.

Now available worldwide

Pettersson’s company was able to put the product to good use, and the inventor himself quickly recognized what this simple gadget meant for shipping as a whole. But being a seafarer through and through, he wanted to focus on the open seas rather than the workshop or office.

In 2015 Pettersson met Frank Fischer, technical director for Turbulo products at SKF, who had just heard of the Sludge Buoy. They agreed that as efficiency requirements for shipowners would continue to rise, the device would become more important for the whole market. After just a few weeks, both parties were convinced that Sludge Buoy would gain a strong foothold in the international shipping scene. This has been SKF’s focus ever since. Ships of all kinds can now implement the skimming system.

How Turbulo Sludge Buoy works:

Turbulo Sludge Buoy—tank skimming equipment
Learn more about the system at:

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