Separation performance standards

摘要

Of all the contaminants contained in residual fuels, the most damaging are catalytic fines ― hard, abrasive, irregularly shaped particles of aluminium silicate, which must be removed, or at least reduced to acceptable levels before the fuel oil is injected into the engine. If they remain, they can lodge in injection pumps, piston rings and cylinder liners, causing serious wear that can, in time, lead to breakdowns. Kjeld Aabo, senior manager, engineering services MAN B&W and chairman of CIMAC HFO Working Group said in London recently that 'without efficient fuel cleaning the issues are safety and loss of optimum engine layout'. According to ISO 8217 standards, the maximum allowable 'cat fines' in bunkered fuel is 80ppm, but because engine builders typically stipulate a maximum of 15ppm in fuel oil, it is rigorously cleaned by centrifugal separation before it enters the engine.