Two-stage cold start and evaporative control system and apparatus for carrying out same

Claim 2

In a spark-ignition internal combustion engine of the type having an air intake system, a fuel intake system, and a carburetor means interconnected therebetween for mixing of fullrange fuel with air to form a combustible mixture for delivery to combustion chambers of said engine, the improvement for reducing exhaust pollutants of said engine by dynamically varying the composition of said full-range fuel during cold starting of said engine (cold start cycle), comprising; i. two-stage cannister means selectively connectable between said carburetor and a reservoir of said full-range fuel and including separate first and second adsorption beds of adsorbent material each in flow arrangement with said reservoir means whereby said full-range fuel dynamically percolates thereover during said cold starting of said engine to elute first and second cold start fuel streams, ii. said first stream being an atomized spray composed essentially of low molecular weight constituents and being carried into said carburetor by intake air of said air intake system, iii. said second stream being composed essentially of low molecular weight liquid constituents and being conveyed under pressure to a fuel well of said carburetor, said first and second streams being mixed together along with air by said carburetor to form a highly combustible cold start mixture for delivery to said combustion chambers of said engine, iv. control means including flow condition means for controlling flow of said fuel including said cold start fuel streams between said reservoir means, said cannister means and said carburetor as a function of at least one of several engine operating parameters to assure at least substantially simultaneous delivery of said cold start fuel streams to said carburetor during cold starting of said engine.

Claim 3

The improvement of claim 1 in which said flow condition means of said control means is further characterized by a first active state initiated by occurrence of a selected engine parameter indicative of the start of said cold start cycle whereby said full-range fuel is allowed to flow in parallel from said reservoir means to each of said adsorbent beds in said cannister means to initiate elution of said first and second cold start fuel streams and whereby said first and second cold start fuel streams are allowed to flow in parallel from said cannister means to said carburetor to form said highly combustible cold start fuel-air mixture.

Claim 4

The improvement of claim 2 in which said absorbent materials comprising said first and second adsorbent beds are selected on a basis of providing efficient retardation of high molecular weight constituents of said full-range fuel percolating therethrough so that essentially only low molecular weight constituents are eluted from each of said beds of said cannister means during cold starting of said engine.

Claim 5

The improvement of claim 3 in which said adsorbent material is selected from the group consisting of silica gel, alumina, barium sulfate, calcium carbonate, glass, resins and plastics, quartz, titanium dioxide, metallic oxides and zeolites, adapted for use in liquid-liquid partition chromatography.

Claim 6

Apparatus for reducing exhaust and inoperative pollutants produced by a spark-ignition internal combustion engine of the type including an air intake system, fuel intake system, and a carburetor interconnected therebetween for mixing full-range fuel with air to form a combustible mixture for delivery to combustion chambers of said engine, comprising: i. a two-stage cannister assembly including first and second sections each containing a bed of adsorbent material capable of selectively eluting at cold start first and second parallel cold start fuel streams each composed essentially of only low molecular weight constituents, said first stream being composed of low molecular weight liquid constituents conveyed to a fuel well of said carburetor said second stream being an atomized spray carried into said carburetor by intake air of said air intake systems, said first and second streams being mixed together with air by said carburetor, said first section also including another bed of adsorbent material capable of selectively absorbing vapor constituents of said full-range fuel during an inoperative state of said engine, ii. valve and conduit network means attached between said cannister assembly, a reservoir means for said full-range fuel and said carburetor for providing selective flow of said fuel including said cold start fuel between said cannister assembly, said reservoir means and said carburetor, said network means including a first plurality of conduit and valve means including first and second valve means controlling parallel flow relative to each of said sections of said cannister assembly so as to allow, (a) in a first operating state flow of said full-range fuel from said reservoir means to said each section and flow of said first cold start fuel stream from said cannister assembly to said carburetor to provide for rapid starting of said engine without producing excessive exhaust pollutants and (b) in a second operating state, full-range fuel to flow from said reservoir means to said carburetor bypassing said cannister assembly after said engine is in a normal running condition, said network means also including a second plurality of conduit means including a third valve means operatively connected between said another bed of said first section of said cannister assembly said fuel reservoir means and said carburetor for selectively conveying vapor emissions of said fuel within said fuel reservoir and/or said carburetor to said another bed when said engine is in said inoperative state, iii. control means operatively connected to said first, second and third valve means of said valve and conduit network for changing operation states so as to direct fuel flow relative to said cannister assembly, said reservoir and carburetor as a function of one or more engine operating parameters.

Claim 7

Apparatus for reducing exhaust and inoperative pollutants produced by a spark-ignition internal combustion engine of the type including an air intake system, fuel intake system, and a carburetor interconnected therebetween for mixing full-range fuel with air to form a combustible mixture for delivery to combustion chambers of said engine, comprising: i. a two-stage cannister assembly including first and second sections each containing a bed of adsorbent material capable of selectively eluting at cold start first and second parallel cold start fuel streams each composed essentially of only low molecular weight constituents, said first stream being composed of low molecular weight liquid constituents conveyed to a fuel well of said carburetor said second stream being an atomized spray carried into said carburetor by intake air of said air intake systems, said first and second streams being mixed together with air by said carburetor, said first section also including another bed of adsorbent material capable of selectively absorbing vapor constituents of said full-range fuel during an inoperative state of said engine, ii. valve and conduit network means attached between said cannister assembly, a reservoir means for said full-range fuel and said carburetor for providing selective flow of said fuel including said cold start fuel between said cannister assembly, said reservoir means and said carburetor, said network means including a first plurality of conduit and valve means including first and second valve means controlling parallel flow relative to each of said sections of said cannister assembly so as to allow, (a) in a first operating state flow of said full-range fuel from said reservoir means to said each section and flow of said first cold start fuel stream from said cannister assembly to said carburetor to provide for rapid starting of said engine without producing excessive exhaust pollutants and (b) in a second operating state, full-range fuel to flow from said reservoir means to said carburetor bypassing said cannister assembly after said engine is in a normal running condition, said network means also including a second plurality of conduit means including a third valve means operatively connected between said another bed of said first section of said cannister assembly said fuel reservoir means and said carburetor for selectively conveying vapor emissions of said fuel within said fuel reservoir and/or said carburetor to said another bed when said engine is in said inoperative state, iii. control means operatively connected to said first, second and third valve means of said valve and conduit network for changing operation states so as to direct fuel flow relative to said cannister assembly, said reservoir and carburetor as a function of one or more engine operating parameters.

Claim 8

Apparatus of claim 5 in which said carburetor includes a fuel well and a bore each in selective contact with said first and second sections of said cannister assembly and said reservoir means through said first plurality of conduit means including said first and second valve means, said first valve means being positioned between said reservoir means and a parallel inlet of each of said sections of said cannister assembly and having first and second operating states for controlling flow of full-range fuel between said reservoir means relative to each of said section and said second valve means, said second valve means being positioned between said fuel well and an outlet of said first section and also having first and second operating states coextensive in time with said operating state of said first valve means for controlling flow of said full-range fuel and said cold start fuel stream from said first sections relative to said fuel well as a function of engine temperature.

Claim 9

The apparatus of claim 6 in which said fuel well and said reservoir means are placed in selective vapor contact with said another bed of said first section through said second plurality of conduit means including said third valve means as a function of a selective engine parameter indicative of said inoperative state in said engine whereby evaporative vapor emissions from said full-range fuel within said fuel well and said reservoir means can be conveyed to said another bed of said first section for adsorption therein thereby preventing escape into atmosphere surrounding said engine.

Claim 10

Apparatus of claim 7 in which said first and second adsorbent beds are formed of a polar adsorbent material while said another adsorbent bed is formed of a nonpolar adsorbent material.

Claim 11

Apparatus of claim 6 in which said first section includes an elongated tubular means disposed within a forward section of a shell housing while said second section is disposed within a rear section of said shell housing with air intake control means connected to a source of heated gas, so as to allow selective flow of said heated gas through said first and second sections for purging both said first, second and another bed of adsorbed fuel constituents, said purged constituents being carried into and consumed within said combustion chambers of said engine.

Claim 12

Apparatus of claim 9 in which said air intake system includes an air cleaner assembly having an air intake line and an air filter, said air intake line including support means for rigidly supporting said cannister assembly in flow relationship with a bore of said carburetor.