6.7 Oil purifiers and coalescers
The main source of contamination of lubricating oil is the leakage of steam from the rotor gland seals. This steam condenses upon contact with the bearing housing and the cold lubricating oil, which results in condensate being dispersed through the oil.
The oil also collects wear particles, oxides, soluble acids and sludge. These need to be removed from the oil to ensure its long life and efficient lubrication. There are two main systems used on continuous by-pass duty whilst the unit is in operation, and an oil regeneration system is also used in the station oil system. The on-line systems are described in the sections which follow.