Marine Oil Purifier
Oil purifiers are used on board ship to condition fuel oil and lubricating oil.
The fuel oil used on ships is normally very thick and viscous at normal temperatures. It is called Class C Marine Bunker oil. It contains a lot of impurities too.
Lubricating oil for diesel engines do get contaminated with carbon deposits, byproducts of oxidation, sludge and metal particles.
The oil to be purified is first allowed to settle in a settling tank. Any large particles will settle out and can be drained every watch. After the oil has time to settle, it is passed through fine meshed wire filters to remove any coarse particles. The oil is then sent to the oil purifier.
The oil purifier makes use of centrifugal force to separate fine solids which cannot be filtered out from the oil.
By rotating the bowl at a very high speed of 15000 rpm or so, the fine solids are separated from the oil.
At these high speeds, the shaft balancing, bearings, and vibration damping mechanism is critical. The high speeds can be achieved by worm-and-wheel drive.
The building up of speed during starting up is achieved by using friction pads. To prevent serious damage to the drive in case of seizures or overload, a shear pin, or shear coupling mechanism is installed between the motor drive and the driven gears.
Although the oil purifier is made to be automatically self flushing, it still needs to be dismantled for manual cleaning periodically. On the ship, very often, the purifiers are maintained by the Junior Engineer.
When the Bunker Fuel oil is of very poor quality, the purifiers have to be opened up very often. The fuel oil purifier room is very often oily, slippery, and hot because the fuel oil is heated to temperatures up to 130 degree Celsius.
The original Posted by Thomas Yoon / Marine Engineer World