Abstract: A by-pass oil refining device for an internal combustion engine is equipped with an atomizing nozzle that constricts oil flow from a solid contaminant filtering element to a vaporization chamber where liquid contaminants are vaporized. The atomizing nozzle has a constricting orifice which is of a diameter sufficiently large to allow recirculation of oil to the vehicle engine, but which is small enough so that oil emanating from the filtering element and entering the vaporization chamber is atomized into a mist. Atomization of the oil significantly increases the extent to which liquid contaminants are vaporized and removed.