Isao Kimura

Consideration on Measurement Methods and Estimation of Lub. oil Contamination for Marine Diesel Engines

In the conventional system of lubrication, lubricating oil is renewed with fresh oil after it is used for some period. Accordingly, waste oil is generated in the conventional system.The authors have developed a new system that makes it possible to use lubricating oil semi-permanently without oil renewal. In the new system, therefore, no waste oil is generated and it is enough to supply only a small amount of fresh oil sometimes to compensate for the lost oil. This system has been working well in about one thousand units of marine and cogeneration diesel engines in practice. The new system always keeps the lubricating oil clean as the kidney of animals kepps their blood always clean. This is why lubricating oil can be used semi-permanently and the new system is called kidney system. In our experience of the kidney system in practical use, we have come to know that there are some problems in the present methods of measurement and estimation of contamination of lubricating oil in marine diesel engines This paper reports about our study on measuring normal pentane insolubles and particles in used lubricating oil.