In combination with an internal combustion engine, a device for the purification of lubricating oil. Installed as a bypass between the outlet side of the oil pump and the crankcase, the device refines contaminated oil by boiling off under a suitable temperature range condition, contaminants such as condensed...http://www.google.es/patents/US4217221?utm_source=gb-gplus-sharePatente US4217221 - Oil refining apparatus
