Patent ID: 8118909

Claim:
A method for separating oil from blowby gas of an internal combustion engine, including providing increased separation efficiency early in the life of the engine without suffering objectionably high pressure drop late in the life of the engine including end-of-life condition of the engine, said method comprising providing an inertial air-oil separator for removing oil particles from said blowby gas, providing said separator with a housing having an inlet for receiving a blowby gas stream from said engine, and an outlet for discharging an air stream, providing first and second flow branches through said housing from said inlet to said outlet, providing said first flow branch with a first set of one or more nozzles receiving said blowby gas stream from said inlet and accelerating said blowby gas stream in said first flow branch in a downstream direction through said first set of one or more nozzles and against a first inertial impactor collector in said housing in the path of said accelerated blowby gas stream through said first flow branch and causing oil particle separation, providing said second flow branch with a second set of one or more nozzles receiving said blowby gas stream from said inlet and accelerating said blowby gas stream in said second flow branch in a downstream direction through said second set of one or more nozzles and against a second inertial impactor collector in said housing in the path of said accelerated blowby gas stream through said second flow branch and causing oil particle separation, providing a variable flow controller in said second flow branch and controlling flow therethrough responsive to pressure of said blowby gas stream, and responding to increasing pressure of said blowby gas stream to increase flow of said blowby gas stream through said second flow branch during the life of the engine.