In order to ensure the proper performance in the mechanism of ship, the use of lubricants and their parameters plays an important role. Here the main engine lube oil system manages the entire function as it pressurizes the oil, circulate it throughout the filters and cooler and then distribute it to all moving part of the ship’s diesel engine. Whether the lubricant oil is animal based (whale oil), mineral based (mineral) or vegetable based(linseed), it is always consider to dissolve heat, prevent wear and tear for the surface of moving components and reduce friction. At present, mineral lubricants producing from the crude oil and synthetic oil involving the use of ester or polyglycols are being massively used in the marine engines.
In this article, we are focusing on the properties and applications of mineral lubricant oils for marine diesel engines. These are essential to know while choosing lubricant oils for marine engine as choosing a low quality lubricant oil can cause several problems for it.
Essential Properties of Lubricating Oils for Ships
While looking for lube oils for ships, you must consider some essential properties as mentioned below-
The most important property for any lubricant oil is viscosity that ensures the ability of the oil to flow on a specific pressure and temperature. By considering the application as well as operating temperature range, the viscosity is calculated.
In the low flash point, lubricant oil can ignite properly for the volatility. Volatility of lube oil is important for preventing crankcase explosions. In case of low flash point, the high temperature of hot spot can cause an explosion by ignition of lubricant oil. Usually the flash point for the marine diesel engine lube oil stays above 200°C.
For cylinder lubrication, alkalinity is important as it ensures the neutralization of acidic sulfur residues from the ignition of HFO.
Among the properties of lubricating oils for ships, presence of detergents is a major factor as these ensure the formation of deposit on the moving component as well as help to maintain the clean oil.
Oiliness ensures the adherence of surfaces like white metal bearing.
Application of Main Engine Lubricant Oil
Now let’s have a look how the application of lubricant oil for main engine system is taken place-
- At first, from the main engine, oil is pumped through the system of duplex oil filters to lube oil cooler where the main engine components stay under pressure.
- The oil is pumped to the main bearing without the direct contact between white metal bearings and steel shaft.
- Within the engine casing, lube oil is also supplied by swivel-jointed pipes and it is carried away to the crossheads, piston cooling, bottom end bearing and many more places.
- For the marine engine cylinders, there is specific lube oil system that ensures the alkaline of the oil to combat acidity. This oil lubricates the frontier of the cylinder wall as well as the piston ring. Thus, application of lubricant oil for the ships are injected everywhere they are required.