Cylinder Oil Blending Unit (COBU)
Cylinder oil is essential for two-stroke engines. Today’s cylinder oils are made with a complex chemistry, and the individual feed rate must therefore be assessed for each oil brand, viscosity class and BN level.
The cylinder oil is used to achieve the necessary level of detergency and dispersion to keep the piston rings and crown clean, and the necessary base number (BN) to neutralize the acids formed during combustion to prevent cold corrosion. The main acid to be neutralized is the Sulphur acid produced from the Sulphur content of the fuel burnt in the engine.
As the Sulphur content and grade of fuel oil are subjected to variation, two stroke engines need the right BN cylinder oil. Lubricant suppliers are finding it practically difficult to supply the required different BN oil, and vessel too cannot set up numerous cylinder oil storage tanks for different grades.
In order to match the properties of the commercially available cylinder oil with the Sulphur content, VTS and Gulf Oil Marine have recently developed a Cylinder Oil Blending Unit (COBU) thanks to a mutual R&D project.
The unit was developed and prototyped by VTS under the specifications provided by the Gulf Oil Marine.
COBU is a unit able to blend two different lubricating oils at different BN to obtain a customized BN. The unit is fully automated allowing the oil blending to obtain the required BN, the oil heating and the precisely measure of the oil consumption. The unit can be easily mounted on board replacing the heater tank and can be connected to a monitoring system in engine control room accessible worldwide using ship connection.