Multi-stage fluid filter, and methods of making and using same

A fluid filter, comprising:

• a hollow casing having a base plate for placement proximate a mounting surface, said base plate having an outlet aperture formed therethrough and an inlet aperture formed therethrough and spaced apart from said outlet aperture;
• a mechanically active filter element disposed within said casing and spaced away from said base plate;
• a substantially cylindrical dividing wall member disposed within said casing adjacent said base plate;
• said dividing wall member defining an inlet flow channel on the outside thereof within the casing and in fluid communication with said inlet aperture of said base plate,
• said dividing wall member further defining an outlet flow channel therein in fluid communication with said outlet aperture of said base plate;
• and
• a chemically active filter member disposed within said inlet flow channel of said casing, said chemically active filter member comprising a nonwoven fiber web comprising a plurality of elongated fibers with each of said fibers having an outer surface;
• each of said fibers further including a longitudinally extending internal cavity formed therein, and including a longitudinally extending slot formed therein extending from the internal cavity to the outer fiber surface;
• and chemical reagent disposed within said internal cavities of said fibers.

A supplemental cartridge for use in conjunction with a fluid filter, said supplemental cartridge comprising:

• a hollow casing, comprising
• a base plate for placement proximate a mounting surface, said base plate having an outlet aperture formed substantially centrally therethrough and an inlet aperture formed therethrough and spaced apart from said outlet aperture;
• a cap opposite said base plate for placement proximate a fluid filter, said cap having an inlet aperture formed substantially centrally therethrough and an outlet aperture formed therethrough and spaced apart from said inlet aperture;
• an outer wall connecting said cap and said base plate;
• a substantially cylindrical dividing wall member disposed within said casing and separating said casing interior into an inlet flow channel in fluid communication with said inlet aperture of said base plate, and an outlet flow channel in fluid communication with said outlet aperture of said base plate;
• and
• a chemically active filter member disposed within said inlet flow channel of said casing, said chemically active filter member comprising a nonwoven fiber web comprising a plurality of elongated fibers with each said fiber having an outer surface;
• each of said fibers further including a longitudinally extending internal cavity formed therein, and including a longitudinally extending slot formed therein extending from the internal cavity to the outer fiber surface;
• and
• a chemical reagent disposed within said internal cavities of said fibers.

A method for removing contaminants from lubricating oil within an engine, said method comprising the steps of:

• circulating said lubricating oil through an engine;
• passing said lubricating oil into an oil filter comprising:
• a casing defining a hollow space therein;
• a porous mechanically active filter element retained within said space;
• and
• a chemically active filter element comprising a nonwoven web of fibers retained within said space, said web comprising:
• a plurality of elongated fibers, with each said fiber having an outer surface and a longitudinally extending internal cavity formed therein with a slot formed therein which extends longitudinally along the surface of the fiber between the internal cavity and the outer fiber surface;
• and
• a reagent retained within the internal cavities of said elongate fibers, said reagent tending to react with contaminants which may be present in said lubricating oil;
• and
• circulating said lubricating oil within said oil filter through said nonwoven web of fibers.

A method for supplying an additive to lubricating oil, comprising the steps of

• circulating said lubricating oil through an engine;
• passing said lubricating oil through an oil filter comprising:
• a casing defining a hollow space therein;
• a porous, mechanically active filter element retained within said space;
• and
• a chemically active filter element comprising a nonwoven web of fibers retained within said space, said web comprising:
• a plurality of elongated fibers, with each said fiber having an outer surface and a longitudinally extending internal cavity formed therein with a slot formed therein which extends longitudinally along the surface of the fiber between the internal cavity and the outer fiber surface;
• and
• an oil additive disposed within the internal cavities of said elongate fibers, whereby an amount of said additive is transferred into said lubricating oil.