US3665906A - Vapor control system for an engine to eliminate smog - Google Patents

Abstract

A vapor absorption system for an internal combustion engine provides for a replenishing flow of oil to coat an absorber unit so as to keep a high efficiency operation. A desired oil flow to the evaporation control unit may be a portion of the oil from the engine crankcase lubrication system which, in turn, includes a crankcase ventilation valve in a line to the engine intake manifold so that sorbed vapors are effectively removed from the oil returning from the sorption unit.

Description

O United States Patent 1 51 3,665,906

De Palma 1 51 May 30, 1972 54 VAPOR CONTROL SYSTEM FOR AN 3,368,326 2/1968 Hervert ..l23/136 x ENGINE TO ELIMINATE SMOG 3,456,635 7/1969 Hervert... 123/136 3,477,210 l1/1969 Hervert ..l23/ll9 X [721 lnvenm Ted De Palm 3,515,108 6/1970 Deeter et a]. 123/ 1 36 [73] Assignee: Universal Oil Products Company, Des

Plaines, Ill. Primary ExaminerLaurence M. Goodridge [22] Filed: Dec. 29 1969 Attorney.lames R. Hoatson, Jr. and Philip T. Liggett [21] Appl. No.: 888,259 [57] ABSTRACT A vapor absorption system for an internal combustion engine U-S- B provides for a replenishing flow of to coat an absorber unit [51] Int. Cl. ..F02m 59/00 so as to keep a high m i operation A desired 0 fl to [58] Fleld of Search ..i23/l 19, 136; 55/228 the evaporation control unit may be a portion of the Oil from the engine crankcase lubrication system which, in turn, in- [56] Rem-em cued cludes a crankcase ventilation valve in a line to the engine in- UNITED STATES PATENTS 2,012,962 9/1935 Hagar ..55/228 3/1965 Berg ..123/136 X 0/! From E n gin 9 System Gas Tank Vent take manifold so that sorbed vapors are effectively removed from the oil returning from the sorption unit.

3 Claims, 3 Drawing Figures 7 Air ln/ef Some! Filler Un/l Oil Return Patented May 30, 1972 //V l/E/V 70/? Tea V. DePa/mo Air ln/ef Sorber F ille r Uni/ 0/7 Refurn Opera/ion External l enl Carbure/or Low Speed Valve A TTOR/VEYS High Speed Opera/ion F /'g u r e 3 34 Plllrlge; 4/!

n e wi fi 01/ Outlet I 0/'/ From E ngl'ne System 605 Tan/r Venl VAPOR CONTROL SYSTEM FOR AN ENGINE TO ELIMINATE SMOG The present invention relates to an improved fuel evaporation control system for an internal combustion engine. More particularly, the invention is directed to an operation which provides for the freshening of a hydrocarbon absorbing oil film to a vapor sorber unit so as to increase the efficiency of the sorber in preventing fuel losses to the atmosphere.

In connection with internal combustion engines, it has been realized that there are gasoline vapors being evaporated from the fuel tank and from the carburetor which contribute to the air pollution and smog problems along with engine exhaust fumes. These evaporated fumes, frequently called hot-soak losses may be substantially reduced by placing various types of vapor absorption materials in the vent pathways such that they are precluded from reaching the atmosphere; however, most sorption materials or beds, other than activated carbon, tend to be hydrophyllic and lose their efficiency for hydrocarbon vapor absorption. In accordance with the present invention, a changing oil film or coating is provided for use in combination with a vapor absorptive bed or unit so as to improve the efficiency of the latter.

Sorption units may, of course, be of differing styles and designs and may be placed in different locations with respect to the engine and/or with respect to a fuel tank. Forexample, it is to be noted that carburetors may be of two types with respect to venting, i.e., they are of the internal vent" design and of the extemal vent" design. With the latter, a suitable absorption canister along side of a carburetor can be used to collect vapors fromthe carburetor as well as from a vent line leading from the gasoline tank. On the other hand, in connection with an internal vent carburetor, the absorption unit may be conveniently combined with the air filter unit that is normally positioned above the carburetor and engine.

Although the control of vapor emissions has been tried in various manners, it is an object of the present invention to provide for an improved efficiency operation through the use of an oil coating over, or in combination with, a vaporabsorption bed such that there is a fresh oil film at least periodically supplied to the sorption medium.

It is a further object of the invention to provide for the use of a recirculating oil stream from the internal combustion engine lubrication system such that a changing oil film is provided to the absorption unit to, in turn, enhance the gasoline vapor sorption efficiency of such unit. In addition, the recirculating oil should be from a system that incorporates a PCV (positive crankcase vent) arrangement so that absorbed vapors passing to the crankcase of the engine will have such fuel vapors released from the oil through the crankcase ventilation valve to the engine fuel intake system and thence passed into the engine itself.

Generally, the crankcase oil for an automotive engine is a No. to No. 30 SAE oil, or a combination -30 grade lube oil, and such oils will serve quite satisfactorily as an absorption media to entrap hydrocarbon vapors in the gasoline boiling range. However, other oil types and recirculating systems may be used in combination with a vapor absorber unit and be within the scope of the present invention.

In a broad aspect, the present invention provides in combination with the air-intake section of an internal combustion engine having a hydrocarbon vapor sorber unit arranged to receive and trap vapors that evaporate from the fuel system for the engine, the improvement that provides an oil coating to said sorber unit from an oil circulating system that, in turn, comprises an oil distributor means to the upper portion of said sorber unit, conduit means from an oil supply source to said distributor means, and oil withdrawal means for removing contacted oil from such unit.

In a preferred arrangement, the vapor absorption unit will provide for receiving vented vapors from a carburetor bowl as well as from a fuel tank of an automotive vehicle and will provide for a circulating oil system that will at least periodically provide a fresh oil film or coating to a vapor absorbing bed such that there is a relatively high level of absorption efficiency maintained in the absorber unit for the automobile. It is also of advantage in a preferred embodiment to make use of at least a portion of the engine oil from the engine lubricating system to provide an oil film in the vapor absorption unit, so that upon engine operation there will be a change of oil film to the latter and means for effecting the removal of sorbed vapors from the oil stream within the crankcase of the engine. In other words, with our modern day automobile engines, it is the practice to have a PCV arrangement where there is a controlled means for venting the vapors from the crankcase oil andpassing such released vapors into the carburetor or fuelintake manifold for the engine so that such vapors will be burned and not reach the atmosphere as smog forming materials.

It may bestill further pointed out that as shown in connection with U.S. Pat. Nos. 3,368,326, 3,456,635, and 3,477,210, it can be of advantage to have the vapor absorption unit positioned to be in combination with the air filter and within the air-intake system to the engine carburetor. By placing the sorber unit along with the air filter unit, or in combination therewith, there is provided a convenient means for collecting vapors from an internal vent type carburetor and an automatic means for effectinga desorption of the unit as the auto engine is operated at speeds above an idling range such that air is sucked into the engine through the sorber unit in a manner effecting a desired desorption flow therethrough. A sorber unit above the carburetor, or along side thereof, may also have lines connecting thereto from a gas tank vent, or from an external vent carburetonso that these vented vapors will also be sorbed and desorbed responsive to the air-intake flow through the sorber-filter unit. In the operation of the unit, at

such times that the engine is shut ofi or idling at a low rate of speed, after the engine is heated up, vented vapors will be permitted to absorb into the absorbing element. Subsequently, with a higher speedoperation, there will be a sufficient air flowthrough the sorbervfilter element or bed toward the engine so that resulting desorbed vapors can be carried directly into the carburetor and into combustion chambers ofthe engine. At the same time, in accordance with the present improved system of this invention, there will be a flow of oil film or oil coating over the sorber material and a transfer of the used oil with sorbed vapors into the crankcase of the engine lubricating system. In the latter, the oil will be freed of absorbed vapors as hereinbefore pointed out in connection with a positive crankcase vent system.

It is, of course, not intended to limit the absorption bed or material over which the oil willflow in accordance with the present invention to any one specific material or to any one specific type of absorbing bed arrangement. The absorber bed may be composed of particulated material, such as spheres or pellets of carbon, alumina, silica, silica-alumina, etc., or it may comprise a porous fiberous media in the form of a mat, strands, particulates, or in a corrugated paper form, etc. The absorber bed or unit may also make use of various plastic open-cell foam materials, such as polyurethane, polyethylene, polystyrene, etc., and there may be one or more pieces of absorption material, as long as they are suitably positioned to be readily coated with an oil film from a recirculating oil system.

Reference to the accompanying drawing and the following description thereof will serve to illustrate an embodiment of the present improved vapor absorption system as well as variations in design and positioning of an absorption section which may be incorporated into the system for use with automotive vehicles.

FIG. 1 of the drawing is a diagrammatic elevational view, partially in section, indicating an oil wetted sorber-filter element which may be positioned to be in combination with a carburetor air-intake system.

FIG. 2 of the drawing indicates the use of a separate canister form of sorber-filter unit which is located separate and apart from the air-filter unit to the carburetor system.

FIG. 3 of the drawing indicates an arrangement similar to that of FIG. 2, with an indication that high speed engine operations will have purge air assist the oil flow in effecting the removal of sorbed vapors from the vapor absorbing unit.

Referring now particularly to FIG. 1 of the drawing, there is indicated an automotive engine 1 with a carburetor 2, in turn having an inlet section 3 and a float bowl section 4 for supplying an air-fuel mixture to the engine manifold section 5. Attached to the upper inlet end of the carburetor, there is provided an air-intake arrangement with an air filter housing 6 having air-intake opening 7 and a removable cover means 8.

The present embodiment indicates a combination sorberfilter element 9 in the form of a cylinder or doughnut and in an annular position within housing 6 whereby air entering inlet 7 will pass radially inwardly through the element into the intake end 3 of carburetor 2. Thus, with the element 9 in the same position when the engine is turned off or is idling at slow speeds, the gasoline vapors from the interior of the carburetor, such as from internal vent means 10, will rise upwardly into the interior of the air-intake housing 6, as shown by the dash line arrows, to be absorbed in the sorber-filter element 9. In order that the ring-type sorber-filter unit 9 of the present embodiment may also collect vaporsfrom the engine fuel tank, there is indicated a line 1 1 connecting with the upper carburetor portion 3 or alternatively, connecting to the side of the housing 6 at 11.

In accordance with the present invention for an improved means of effecting sorption of light vapors, there is the provision of an oil stream into and over the surface of the sorberfilter unit 9 by way of a perforate distribution means 12. The latter is indicated diagrammatically to be of a circular form with a U-shaped cross section so as to receive oil from line 13 and then distribute the oil by way of holes 14 on to the sorber unit 9. Positioned below the latter and within the bottom portion of housing 6, there is a downwardly dished ring section 15 for collecting the oil from sorber 9 and transferring it by way of line 16 to a crankcase section 17 of the engine 1. The oil supply line 13 is also indicated diagrammatically as connected to the side portion of engine 1 at zone 18 in a manner to communicate with the pressured lubricating oil system for the engine so that when the engine is running there is a continuous fresh supply of oil by way of line 13 to distributor ring 12 and to the surface of the sorber-filter unit 9.

In order to assure the removal of sorbed vapors from the oil stream retained by way of line 16 to crankcase 17, the oil circulation system and the crankcase vent for the engine is preferably of the type where there is a closed vent arrangement. In other words, there shall be a crankcase vent means 19 connecting with a PCV valve 20 and a line 21 that carries released vapors to the intake manifold 5 for the engine 1. It will thus be seen that the present system provides a dual arrangement for increasing the efficiency of the collection of gasoline vapors in connection with an automotive internal combustion engine. In one instance, the air-intake flow to the carburetor provides for the partial removal of absorbed light vapors and their transfer into the carburetor and intake manifold section of the engine; while in another instance, the light gasoline vapors are sorbed by the oil film on the surface of the sorber filter element 9 are then carried along in the oil return line 16 to be discharged into the crankcase l7 and thence allowed to pass by way of PCV valve and line 21 to the fuel intake manifold of the engine and be burned in the cylinders thereof.

Referring now particularly to both FIGS. 2 and 3 of the drawing, there is shown a carburetor 22 with a float bowl section 23 receiving gasoline by way of line 24, while at the upper portion thereof, there is a connecting air filter housing 25 suitable to effect the filtering of air carrying through the carburetor to the engine intake manifold. In the present embodiment, there is indicated an external vent type carburetor with vent means 26 carrying through a two-way valve 27 to line 28, or optionally to a line 26', as indicated in FIG. 3. Line 28, as indicated, provides for passing gasoline vapors into a suitable sorber-filter unit 29 having a sorption bed or sorbent material 30 capable of substantially absorbing all of the light hydrocarbon vapors that may be carried to the canister bed 30. In accordance with the present invention, the sorbent material 30 in unit 29 will have provision for receiving an oil coating from an oil stream that is supplied by way of line 31 and then withdrawn by way of line 32. Although not shown in the drawing, lines 30 and 32 will preferably supply a portion of oil from the engine lubrication system in a manner shown and described in connection with FIG. 1 of the drawing.

Although not considered to be limiting, it is to be noted that the two-way valve 27 is shown to be operated by a linkage means 33 which can be positioned responsive to an accelerator means or other control device that in turn moves or is moved responsive to engine speed. In other words, it is provided that the valve 27 will be in a position to permit vented vapors from line 26 to carry into the sorber material 29 when an engine has been shut off or when it is operating at an idling condition. While, conversely, as the engine is speeded up and linkage means 33 moves from the position in 32 into the position of FIG. 3, there is a path change through valve 27 providing that purge air will pass from air inlet means 34 down through the container 29 and bed 30 to line 28 and thence to line 35 to effect a desorption of at least a portion of the entrapped vapors and carry them into air filter unit 25 to eventually reach the carburetor 22 and the engine intake manifold system. In addition to the removal of vapors carried into the carburetor system, there will be the entrapment of vapors in the oil film on absorbent material 30 and a continuous removal of such vapors with the oil stream discharge by way of outlet line 32 to carry on to the crankcase of the engine where eventually the vapors will be freed by way of the PCV valve ar rangement and carried to the engine intake manifold.

It is to be noted that the canister sorber-filter unit as provided in FIGS. 2 and 3 of the drawing provides an optional arrangement and positioning with respect to the carburetor and engine as indicated in FIG. 1. However, still other forms of absorber units and/0r combination sorber-filter units may well be provided within the scope of the present invention to effect the entrapment of hot soak loss vapors and gas tank vent vapors. Also, it is to be noted that in FIGS. 2 and 3 the gas tank vent line 36 is shown connecting with the side portion of canister 29 in order that such vapors may carry into the sorber-element 30, although it may be again pointed out that this arrangement is merely one embodiment and that other arrangements may be provided to effect the transfer of gas tank vapors into a suitably located sorption unit. However, in all cases, each unit will have means for passing an oil stream into or over the sorber section so as to enhance the sorption ability of the material being used in the system or at least an effect with such material.

Still further, although a linkage arrangement has been provided to operate desorption in embodiments of FIGS. 2 and 3 responsive to engine speed, there may be other provisions to operate a movable valving means so that sorption and desorption will be carried out in the sorber unit at the proper intervals. An alternative may, for example, comprise the use of an electric solenoid switch which would move the valve responsive to engine shut-off or to engine speed so as to insure an air purge along with at least intermittant oil circulation through the sorber bed at such times as the engine is operating at higher speeds.

I claim as my invention:

1. In combination with the air-intake section of an internal combustion engine having a pumped lubrication system, a crankcase and a ring-type air permeable filter and hydrocarbon vapor sorber unit arranged to traverse the air-intake path and trap vapors that evaporate from the fuel system for the engine, the improvement that provides for a fresh oil coating to said sorber unit from an oil circulating system that, in turn, comprises an oil distributor means to the upper portion of said sorber unit to provide a uniform oil coating thereto, conduit means from said pumped lubrication system to said distributor means to provide oil from the crankcase to the sorber unit surface, said sorber unit having vent lines connecting thereto from the carburetor section of the internal combustion engine and from the fuel tank of the fuel system for the engine, whereby carburetor bowl losses and fuel tank losses will be entirely vented to the oil coated sorber unit for entrapment therein, an oil withdrawal passageway means interconnecting between said sorber unit and said crankcase for transfen'ing vapor containing contacted oil from such unit, and venting means to the engine intake section from said crankcase whereby any released absorbed light hydrocarbon vapors from the oil will be introduced into said engine for combustion therein.

2. The combination of claim 1 further characterized in that

Claims (3)

1. In combination with the air-intake section of an internal combustion engine having a pumped lubrication system, a crankcase and a ring-type air permeable filter and hydrocarbon vapor sorber unit arranged to traverse the air-intake path and trap vapors that evaporate from the fuel system for the engine, the improvement that provides for a fresh oil coating to said sorber unit from an oil circulating system that, in turn, comprises an oil distributor means to the upper portion of said sorber unit to provide a uniform oil coating thereto, conduit means from said pumped lubrication system to said distributor means to provide oil from the crankcase to the sorber unit surface, said sorber unit having vent lines connecting thereto from the carburetor section of the internal combustion engine and from the fuel tank of the fuel system for the engine, whereby carburetor bowl losses and fuel tank losses will be entirely vented to the oil coated sorber unit for entrapment therein, an oil withdrawal passageway means interconnecting between said sorber unit and said crankcase for transferring vapor containing contacted oil from such unit, and venting means to the engine intake section from said crankcase whereby any released absorbed light hydrocarbon vapors from the oil will be introduced into said engine for combustion therein.

2. The combination of claim 1 further characterized in that said oil withdrawal passageway means extends from a dished, ring-shaped collection space below said sorber unit whereby after the oil drains therefrom there is a resulting vapor passageway existant from said crankcase directly to said sorber unit.

3. The improved combination of claim 1 still further characterized in that said oil supply source from the lubrication system of the engine is down stream from an oil pump in said system whereby pressure will carry the oil to the sorber unit at such times that the engine is operating.

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