Fuel filter including slow release additive

Abstract

This invention relates to a fuel filter for use with internal combustion engines. The fuel filter includes a fuel additive that can be released into fuel. The rate of release for the fuel can be controlled. In one form the fuel additive can be released a substantially constant rate to maintain a uniform level of fuel additive in the fuel. Use of the present invention provides a fuel filter having an extended life span that is longer than fuel filters typically used with combustion engines.

What is claimed is:  
     
         1 . A fuel filter for filtering fuel and adapted to release a fuel additive into said fuel at a controlled rate, said fuel filter assembly comprising: 
 a housing assembly including an inlet and an outlet for fuel and defining an filter chamber;    a filter element disposed within said filter chamber and positioned between said inlet and said outlet for fuel;    a source of a fuel additive disposed within said interior chamber; and    a slow release means for controlling the rate of release of the fuel additive into said fuel, said slow release means positioned between said source of fuel additive and said fuel outlet.    
     
     
         2 . The fuel filter assembly of    claim 1    wherein said source of a fuel additive includes a plurality of soluble fuel additive pellets.  
     
     
         3 . The fuel filter assembly of    claim 2    wherein said soluble fuel additive pellets are coated with a hydrocarbon insoluble coating.  
     
     
         4 . The fuel filter assembly of    claim 1    wherein the slow release means includes a hydrocarbon insoluble coating.  
     
     
         5 . The fuel filter assembly of    claim 1    wherein the slow release means includes a diffusion orifice.  
     
     
         6 . The fuel filter assembly of    claim 1    wherein the slow release means includes baffles.  
     
     
         7 . The fuel filter assembly of    claim 1    wherein the slow release means includes a semipermeable membrane.  
     
     
         8 . The fuel filter assembly of    claim 1    wherein said slow release means includes a thermostatically controlled orifice.  
     
     
         9 . A fuel filter for filtering fuel and adapted to release a fuel additive into said fuel, said fuel filter comprising: 
 an outer housing assembly defining a filter chamber, an inlet and an outlet for fuel;    a filter element disposed within said filter chamber and positioned between said inlet and said outlet for fuel;    an inner housing assembly positioned within said filter chamber, said inner housing assembly defining an inner chamber in fluid communication with said filter chamber;    a source of a fuel additive disposed within said inner chamber; and    a diffusion controlled orifice positioned between said source of fuel additive and said fuel outlet.    
     
     
         10 . The fuel filter of    claim 9    wherein said fuel additive is coated with a hydrocarbon insoluble coating.  
     
     
         11 . The fuel filter of    claim 9    further including at least one baffle plate positioned between said orifice and said source of fuel additive.  
     
     
         12 . The fuel filter of    claim 9    wherein said diffusion controlled orifice includes a thermostat.  
     
     
         13 . The fuel filter of    claim 9    wherein said diffusion controlled orifice includes a semipermeable membrane.  
     
     
         14 . A fuel filter for filtering fuel and adapted to release a fuel additive into said fuel, said fuel filter comprising: 
 an outer housing assembly defining a filter chamber, an inlet and an outlet for fuel;    a filter element disposed within said filter chamber and positioned between said inlet and said outlet for fuel;    an inner housing assembly positioned within said filter chamber, said inner housing assembly defining an inner chamber in fluid communication with said filter chamber;    a source of a fuel additive disposed within said inner chamber; and    at least one baffle plate positioned between said source of fuel additive and said fuel outlet.    
     
     
         15 . The fuel filter of    claim 14    wherein said fuel additive is coated with a hydrocarbon insoluble coating.  
     
     
         16 . The fuel filter of    claim 14    wherein said inner housing assembly includes a thermostat.  
     
     
         17 . A fuel filter for filtering fuel and adapted to release a fuel additive into said fuel, said fuel filter comprising: 
 an outer housing assembly defining a filter chamber, an inlet and an outlet for fuel;    a filter element disposed within said filter chamber and positioned between said inlet and said outlet for fuel;    an inner housing assembly positioned within said filter chamber, said inner housing assembly defining an inner chamber in fluid communication with said filter chamber;    a source of a fuel additive disposed within said inner chamber; and    a semipermeable membrane positioned between said source of fuel additive and said fuel outlet.    
     
     
         18 . The fuel filter of    claim 17    wherein said fuel additive is coated with a hydrocarbon insoluble coating.  
     
     
         19 . The fuel filter of    claim 17    wherein said inner housing assembly includes a thermostat.  
     
     
         20 . A method of releasing a fuel additive into fuel, said method comprising the steps of: 
 providing a fuel filter containing a fuel additive, said fuel filter positioned between a source of fuel and an internal combustion engine;    contacting a portion of said fuel additive with a portion of said fuel to provide a fuel composition comprising fuel additive dissolved in said portion of said fuel; and    allowing said fuel composition to admix with said fuel.    
     
     
         21 . The method of    claim 20    wherein said fuel additive is coated with a hydrocarbon insoluble coating.  
     
     
         22 . The method of    claim 20    wherein said allowing includes positioning a diffusion control orifice between said fuel composition and said fuel.  
     
     
         23 . The method of    claim 20    wherein said allowing includes positioning at least one baffle plate between said fuel composition and said fuel.  
     
     
         24 . The method of    claim 20    wherein said allowing includes allowing said fuel composition to diffuse into said fuel when said fuel exhibits a temperature level within a predetermined temperature range.