`

`U.S. Patent
`
`May 24, 2005
`
`Sheet 1 of 5
`
`US 6,896,852 Bl
`
`12
`
`,-10
`
`24
`
`--ttt-ttt-~-------------
`
`38 14
`
`22
`
`18b
`
`FIG. 1
`
`~10
`
`26
`
`12
`
`16
`
`34
`
`34
`
`FIG. 2
`
`L
`
`I
`FIG. 3A
`
`FIG. 3B
`
`

`

`U.S. Patent
`
`May 24, 2005
`
`Sheet 2 of 5
`
`US 6,896,852 Bl
`
`I
`I
`I
`I
`I
`I
`I
`I
`I
`I
`I
`I
`I
`I
`I
`I
`I
`I
`I
`I
`,...
`I 0
`I
`
`I \
`
`I
`I
`I
`I
`I
`I
`I
`I
`
`0
`(0
`
`C\J
`C")
`
`(X)
`
`,...
`
`,...
`
`CD
`
`'¢
`O'>
`
`~
`
`• C,
`~
`~
`
`o
`o
`o
`o
`o o
`0
`0
`o \ o a o o o o o oo o o o o o
`0 0
`gOO
`O
`O
`O O
`O
`0
`ooooo oooo
`o o
`o
`O
`o
`a o O
`goooooooo
`o o o o o
`o: 00 0 0
`
`0 0 0
`0
`O
`O
`gO
`0 OO O O O
`0 0 0 0 0 0 0 0 0 0 0 0 0 0
`
`0 0
`
`0
`
`0 00 0
`
`0 0
`
`0
`
`0
`
`0 0
`
`0 D
`
`O O DO
`
`o o
`oooooo oo:oooogoooooo o o o
`o
`o o a o
`o o oo o
`oo O
`O O O o
`O
`O
`O O
`O O OO ~ 0
`O O
`C
`O
`O D D O
`
`0 OO O O
`
`O O
`
`O
`
`0 O
`
`O
`O O O
`
`D
`
`0
`
`0
`
`o
`
`0
`
`0
`0
`0000
`
`o
`a: 00 0
`ao
`o
`c
`0 o O D
`0 : 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
`O
`o
`o 0
`a
`o o
`o
`o
`0
`Do oDooooooo o
`oOoo ooooo o
`o
`
`0
`
`' .,
`' ' ' \
`
`\ ' \
`
`\ '
`
`0
`0)
`
`0
`0
`O
`0
`O
`oo O O O
`0
`O
`O O
`ooo
`ooaooooooo
`0
`O
`0
`oO O
`oO
`0 °
`oD
`00
`0
`0
`DO O 0 •
`0
`0
`0
`0 0
`0 0 00
`0
`0 0
`oo o o o o
`oo
`oo
`0 0 0 ° 0 0 0
`o o o o o o
`o
`0
`0
`0
`oO
`O
`O O
`o o
`o o
`o
`o
`oo
`Oc
`a
`
`o
`
`o
`
`0
`
`0
`o o o
`a
`
`o
`oo
`
`

`

`U.S. Patent
`
`May 24, 2005
`
`Sheet 3 of 5
`
`US 6,896,852 Bl
`
`10
`
`\
`
`26
`
`/
`~~
`/
`I/
`v
`v
`
`/~
`
`v
`I/
`I/
`I/
`I/
`I/
`I/
`I/
`
`(~
`
`12 ~
`v'
`I/
`I/
`
`510
`
`\
`
`(
`
`512
`
`/
`
`V
`V
`v
`v
`I/
`v
`v
`1./
`v
`v
`v
`I/
`v
`v
`v
`v
`v
`I/
`I/
`I/
`I/
`I/
`(/
`I/
`I/
`I/
`I/
`
`FIG. 5
`
`546a
`
`,.
`
`I/
`I/
`I/
`I/
`1,-
`v
`I/
`6
`~t.---51
`r,
`I,
`l.1
`I/
`II
`I/
`~L,,,-
`
`526
`
`I/
`I/
`I/
`I/
`I/
`I/
`I/
`I/
`I/
`,,.
`I/
`
`FIG. 7 546b
`
`46a
`
`16
`
`/
`
`i
`
`/
`/
`I/
`I,,
`I/
`I/
`I/
`L, ~ L.--
`I/
`I,,
`I/
`I/
`I/
`1,-
`I/
`I/
`I/
`1,-
`I/
`I/
`I/
`I/
`
`~~
`
`46b
`
`FIG. 6
`
`

`

`U.S. Patent
`
`May 24, 2005
`
`Sheet 4 of 5
`
`US 6,896,852 Bl
`
`112
`
`116a
`
`,,--110
`
`118c
`
`116b
`
`FIG. 8
`
`210
`
`216
`
`299
`
`294
`
`,,--200
`
`276
`
`218b
`
`292
`
`290
`
`------ -----
`
`FIG. 9
`
`

`

`U.S. Patent
`U.S. Patent
`
`May 24, 2005
`May24, 2005
`
`Sheet 5 of 5
`Sheet 5 of 5
`
`US 6,896,852 Bl
`US 6,896,852 B1
`
`0
`~
`
`FIG.10
`
`•
`C,
`'"""4
`~
`
`N
`,-
`q-
`
`0
`T"""
`...t
`
`\
`
`0
`(X)
`C")
`
`-.:t"
`C")
`C")
`
`C\J
`LO
`q-
`
`C\J
`T"""
`C")
`
`~
`~
`
`FIG.11
`
`.
`b
`'"""4
`~
`
`(0
`
`.....
`416
`
`'q'"
`
`...t
`LO
`-::I"
`
`454
`
`I
`
`co
`r-
`C')
`
`(
`
`0
`0
`(")
`
`C\J
`C)
`C')
`
`CD
`T"""
`C")
`
`I
`
`I
`
`I
`
`I
`
`I
`I
`I
`I
`' I
`I I
`'
`I
`
`312
`
`

`

`US 6,896,852 Bl
`
`1
`HYDROCARBON BLEED EMISSION
`SCRUBBER WITH LOW RESTRICTION
`
`CROSS REFERENCE TO RELATED
`APPLICATIONS
`
`This application claims the benefit of U.S. Provisional
`Patent Application Ser. No. 60/192,917, filed Mar. 29, 2000.
`
`TECHNICAL FIELD
`
`The present invention relates to evaporative em1ss10ns
`control systems in motor vehicles.
`
`30
`
`2
`causes air to flow from the fuel tank, through the canister,
`out the vent port and into the atmosphere. The air carries the
`hydrocarbon heel out of the canister and into the
`atmosphere, thereby resulting in the release of bleed emis-
`5 SlOnS.
`In order to reduce bleed emissions some motor vehicles
`employ an auxiliary canister. The auxiliary canister is placed
`in series with and further filters the treated air flowing out
`the vent port of the main evaporative canister. The auxiliary
`10 canister typically uses the same sorbent material, i.e., granu(cid:173)
`lar or pelletized carbon, as is used in the main evaporative
`canister to thereby increase the hydrocarbon capacity of the
`evaporative emission control system. However, in order to
`achieve sufficient hydrocarbon capacity, auxiliary canisters
`are generally highly restrictive to the flow of air. Thus, the
`auxiliary canister must be bypassed in order to be compat-
`ible with vehicle refueling vapor recovery systems. Bypass(cid:173)
`ing an auxiliary canister requires the addition of valving and
`conduits to the evaporative emissions control system, and
`thus adds cost and complexity to the system. Furthermore,
`the restrictive air flow characteristics of the auxiliary can-
`ister makes purging the volume of sorbent material
`inefficient, especially in small displacement engines.
`Moreover, vehicles which incorporate a more efficient
`evaporative canister and/or an auxiliary canister typically do
`not reduce bleed emissions to a level required to classify the
`vehicle as a Super Ultra Low Emissions Vehicle (SULEV)
`or as a Practically Zero Emissions Vehicle (PZEV).
`Therefore, what is needed in the art is a device which
`reduces the bleed emissions of an evaporative canister
`and/or the combination of an evaporative canister and an
`auxiliary canister.
`Furthermore, what is needed in the art is a device which
`reduces the bleed emissions from an evaporative canister
`35 and has a low flow restriction, thus rendering the device
`compatible with vehicle refueling vapor recovery systems.
`Yet further, what is needed in the art is a device which
`reduces bleed emissions from an evaporative canister and
`40 has a low flow restriction, thereby increasing purge effi(cid:173)
`ciency.
`Even further, what is needed in the art is a device which
`reduces bleed emissions from an evaporative canister and
`which has a higher efficiency than an auxiliary canister
`45 utilizing carbon pellets or granules.
`SUMMARY OF THE INVENTION
`The present invention provides a hydrocarbon emissions
`scrubber for use in an evaporative emissions control system
`50 of a motor vehicle.
`The invention comprises, in one form thereof, a hydro(cid:173)
`carbon emissions scrubber including a scrubber element
`having an elongate body. The body defines a plurality of
`passageways for the flow of fluid therethrough. The plurality
`of passageways are one of coated with or constructed of a
`sorbent material. The sorbent material is adsorptive of
`hydrocarbons.
`An advantage of the present invention is that bleed
`emissions from an evaporative canister are substantially
`60 reduced.
`Another advantage of the present invention is the hydro(cid:173)
`carbon emissions scrubber is substantially less restrictive to
`the flow of fluid than a typical auxiliary canister, thereby
`rendering the device compatible for use in evaporative
`emissions control systems which incorporate refueling
`vapor recovery and eliminating the need for complex bypass
`valving and conduits.
`
`BACKGROUND OF THE INVENTION
`Motor vehicles emit hydrocarbons as a result of the 15
`evaporation of fuel. Generally, such evaporative emissions
`result from the venting of fuel vapors from the fuel tank due
`to diurnal changes in ambient pressure and/or temperature,
`the vaporization of fuel by a hot engine and/or exhaust
`system, and the escape of fuel vapors during refueling of the 20
`vehicle. The venting of fuel vapor from the fuel tank due to
`diurnal pressure and/or temperature changes (i.e., diurnal
`emissions) is responsible for a majority of evaporative
`emissions. Diurnal changes in pressure and/or temperature
`cause air to flow into and out of the fuel tank. Air flowing 25
`out of the fuel tank inevitably carries fuel vapor which is
`created by the evaporation of fuel into the air contained
`above the fuel within the fuel tank. If this flow of air is left
`untreated and is allowed to escape directly into the
`atmosphere, undesirable emissions occur.
`One way in which motor vehicle manufacturers have
`reduced the level of diurnal emissions is through the use of
`evaporative canisters. A detailed discussion of the structure
`and operation of an evaporative canister is presented in U.S.
`Pat. No. 5,910,637, the disclosure of which is incorporated
`herein by reference.
`Generally, an evaporative canister has a vapor inlet, a
`purge port and a vent port. The vapor inlet is fluidly
`connected by a vapor conduit to the air space in the fuel tank.
`Diurnal changes in pressure and/or temperature causes air
`within the fuel tank to flow through the vapor conduit and
`into the evaporative canister via the vapor inlet. The air
`carries fuel vapor and/or hydrocarbons. The evaporative
`canister contains a sorbent material, such as an activated
`carbon, that strips fuel vapor from the air as it flows through
`the canister. The treated air then flows out the vent port and
`into the in atmosphere. The purge port is fluidly connected
`by a valved purge conduit to the combustion air intake of the
`motor vehicle engine. When the engine is running, the
`combustion air intake is at sub-atmospheric pressure, and
`the valve is opened to thereby connect the purge port to the
`combustion air intake. Fresh air is drawn by the sub(cid:173)
`atmospheric pressure through the vent port and into the
`evaporative canister. The fresh air flows through the sorbent 55
`material, out the purge port and into the combustion air
`intake. The flow of fresh air through the evaporative canister
`strips the sorbent material of stored fuel vapor and/or
`hydrocarbons, thereby purging the evaporative canister of
`hydrocarbons.
`However, minute levels of hydrocarbons remain stored in
`the sorbent material of a purged evaporative canister. Bleed
`emissions are believed to result from the release of these
`stored hydrocarbons (i.e., the hydrocarbon heel) from the
`evaporative canister into the atmosphere. Bleed emissions 65
`typically occur, for example, during the heating of the fuel
`tank during a diurnal cycle. The heating of the fuel tank
`
`

`

`US 6,896,852 Bl
`
`3
`A still further advantage of the present invention is the
`hydrocarbon emissions scrubber has a higher efficiency than
`an auxiliary canister.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The above-mentioned and other features and advantages
`of this invention, and the manner of attaining them, will
`become apparent and be better understood by reference to
`the following description of one embodiment of the inven(cid:173)
`tion in conjunction with the accompanying drawings,
`wherein:
`FIG. 1 is a plan view of one embodiment of a hydrocarbon
`bleed emissions scrubber of the present invention.
`FIG. 2 is a longitudinally sectioned view of the hydro(cid:173)
`carbon bleed emissions scrubber of FIG. 1;
`FIG. 3A is a longitudinally sectioned view of the scrubber
`element of FIG. 2;
`FIG. 3B is a cross-sectional view of the scrubber element
`of FIG. 2;
`FIG. 4 is a schematic diagram of one embodiment of an
`evaporative emissions control system including the hydro(cid:173)
`carbon bleed emissions scrubber of FIG. 1.
`FIG. 5 is a fragmentary, longitudinally sectioned view of
`the hydrocarbon bleed emissions scrubber of FIG. 1;
`FIG. 6 is a longitudinally sectioned view of the hydro(cid:173)
`carbon bleed emissions scrubber of FIG. 1;
`FIG. 7 is longitudinally sectioned view of a second
`embodiment of a hydrocarbon bleed emissions scrubber of
`the present invention;
`FIG. 8 is a longitudinally sectioned view of a third
`embodiment of a hydrocarbon bleed emissions scrubber of
`the present invention;
`FIG. 9 is a plan, partially sectioned view of one embodi(cid:173)
`ment of an evaporative emissions assembly of the present
`invention;
`FIG. 10 is a plan, partially sectioned view of a second
`embodiment of an evaporative emissions assembly of the
`present invention; and
`FIG. 11 is a plan, partially sectioned view of a fourth
`embodiment of a hydrocarbon bleed emissions scrubber of
`the present invention.
`Corresponding reference characters indicate correspond(cid:173)
`ing parts throughout the several views. The exemplification
`set out herein illustrates one preferred embodiment of the
`invention, in one form, and such exemplification is not to be
`construed as limiting the scope of the invention in any
`manner.
`
`DESCRIPTION OF THE PREFERRED
`EMBODIMENT
`Referring now to the drawings, and particularly to FIGS.
`1 and 2, there is shown one embodiment of a hydrocarbon
`emissions scrubber of the present invention. Hydrocarbon 55
`emissions scrubber 10 (hereinafter referred to as HC scrub(cid:173)
`ber 10) includes housing 12, cap 14, scrubber element 16,
`and flow diffusers 18a and 18b. Generally, and as will be
`described more particularly hereinafter, HC scrubber 10 is
`for use in an evaporative emissions control system of a 60
`motor vehicle. HC scrubber 10 is fluidly connected to an
`evaporative canister of the evaporative emissions control
`system, and strips residual fuel vapor and/or hydrocarbons
`from the air flowing from the evaporative canister before
`discharging the air into the atmosphere.
`Housing 12 is an elongate, substantially cylindrical cup(cid:173)
`shaped member having longitudinal central axis A Housing
`
`5
`
`4
`12 includes open, flanged end 22, tubular housing end 24
`and cylindrical sidewall 26. Flanged end 22 and tubular
`housing end 24 are interconnected by substantially cylindri(cid:173)
`cal side wall 26. Flange 28 surrounds housing 12 adjacent
`flanged end 22. Flange 28 is configured to be coupled to cap
`14 in an airtight manner, such as, for example, by thread(cid:173)
`ingly engaging or snap-fitting to cap 14. Tubular housing
`end 24 extends axially from housing 12 at the end thereof
`which is opposite flanged end 22. Tubular housing end 24
`10 defines a passageway for the flow of air and fuel vapor into
`and/or out of housing 12. Tubular housing end 24 is slidingly
`received within a conduit (not shown), and includes barb 30
`which resists axial movement of the conduit in a direction
`away from housing 12. Housing 12 receives scrubber ele-
`15 ment 16 and flow diffusers 18a, 18b, such that each of
`scrubber element 16 and flow diffusers 18a, 18b are sur(cid:173)
`rounded by cylindrical side wall 26. Housing 12 is con(cid:173)
`structed of, for example, an injection molded plastic or other
`suitable material that is substantially resistant to degradation
`20 due to exposure to fuel and fuel vapors.
`Cap 14 includes rim end 32 having tubular cap end 34
`extending axially therefrom. Rim end 32 includes a substan(cid:173)
`tially saucer-shaped rim 36. Rim 36 is configured to be
`coupled to flanged end 22 of housing 12 in an air tight
`25 manner, such as, for example, threadingly and/or snap-fitting
`to flange 28 of flanged end 22. Tubular cap end 34 defines
`a passageway for the flow of air and fuel vapor through cap
`14 into and/or out of housing 12. With cap 14 coupled to
`flanged end 22 of housing 12, a channel for the flow of fluid
`30 through housing 12 is defined by tubular housing end 24,
`tubular cap end 34 and cylindrical side wall 26. Tubular cap
`end 34 is configured to be slidingly received within a conduit
`(not shown), and includes barb 38 which resists axial
`movement of the conduit in a direction away from housing
`35 12.
`Scrubber element 16 is an elongate, substantially cylin(cid:173)
`drical body and is disposed within housing 12. Referring
`now to FIGS. 3A and 3B, scrubber element 16 has central
`axis S, a predetermined length Land diameter D. Scrubber
`40 element 16 has, in cross-section, a matrix or honeycomb-like
`structure, and defines a plurality of axial or longitudinal
`passageways 42 which extend in an axial direction from one
`end (not referenced) to the other end, i.e., through the entire
`length L, of scrubber element 16. Disposed between scrub-
`45 ber element 16 and sidewall 26 of housing 12 are resiliently(cid:173)
`deformable seals 46a and 46b (FIG. 6). Seals 46a and 46b
`sealingly engage sidewall 26 to thereby direct fluid and/or
`air flow through passageways 42 of scrubber element 16 and
`to prevent fluid and/or air flow through any gap between
`50 scrubber element 16 and sidewall 26. Thus, seals 46a and
`46b ensure that substantially all of the air and/or fluid
`flowing into and/or out of housing 12 flows through scrubber
`element 16. Scrubber element 16 is constructed of a sorbent
`material 16a, such as, for example, activated carbon. At least
`the inside surface of each of passageways 42 is formed of or
`covered with sorbent material 16a. Preferably, scrubber
`element 16 is extruded from, for example, a slurry-like
`mixture of sorbent material 16a and a binder.
`Flow diffusers 18a and 18b are substantially cylindrical
`disks that are porous to the flow of air and fuel vapor. Flow
`diffuser 18a is disposed within housing 12 intermediate
`scrubber element 16 and tubular housing end 24 such that
`one side or face (not referenced) of flow diffuser 18a is
`disposed adjacent to scrubber element 16 and the other face
`65 is proximate to tubular housing end 24. Flow diffuser 18b is
`disposed within housing 12 intermediate scrubber element
`16 and cap 14 such that one face of flow diffuser 18b is
`
`

`

`US 6,896,852 Bl
`
`5
`disposed adjacent scrubber element 16 and the other face is
`disposed proximate flanged end 22 of housing 12 and
`proximate to rim 36 of cap 14. Each of flow diffusers 18a
`and 18b are constructed of, for example, a reticulated foam
`or other suitable material.
`Referring now to FIG. 4, one embodiment of an evapo(cid:173)
`rative emissions control system in accordance with the
`present invention is shown. Motor vehicle 60 includes
`internal combustion engine 62 and fuel tank 64. Internal
`combustion engine 62 has combustion air intake 66. Evapo(cid:173)
`rative emissions control system 70 includes, in addition to
`HC scrubber 10, vapor conduit 74, evaporative canister 76,
`vent conduit 78, purge conduit 80, purge valve 82, vent
`valve 84, and air conduit 86.
`Evaporative canister 76 includes purge port 90, vapor
`inlet port 92 and vent port 94. Purge port 90 is fluidly
`connected to combustion air intake 66 by purge conduit 80.
`Purge valve 82 is disposed in fluid communication with
`purge conduit 80 between purge port 90 and combustion air
`intake 66, such as, for example, within purge conduit 80, and
`is operable to selectively control the flow of fuel vapor
`through purge conduit 80 from purge port 90 to combustion
`air intake 66. Purge valve 82 is open, for example, when
`internal combustion engine 62 is running. Vapor inlet port 92
`is fluidly connected to fuel tank 64 by vapor conduit 74. Vent
`port 94 is fluidly connected to HC scrubber 10 by vent
`conduit 78. More particularly, vent conduit 78 is fluidly
`coupled at one end to vent port 94 and at the other end to
`tubular cap end 34 of HC scrubber 10. Tubular housing end
`24 of HC scrubber 10 is fluidly coupled to vent valve 84 by
`air conduit 86. Vent valve 84 is disposed between HC
`scrubber 10 and an air intake and/or discharge assembly (not
`shown), such as, for example, within air conduit 86. Vent
`valve 84 is operable to selectively control the flow of air
`through air conduit 86 into and/or out of HC scrubber 10.
`Vent valve 84 is normally open, and can be selectively
`closed in conjunction with purge valve 82 to perform various
`functions, such as, for example, leak detection and vacuum
`testing of evaporative emissions control system 70. Each of
`vent valve 84 and purge valve 82 are electrically connected 40
`to, for example, an engine control module (not shown), and
`open and close in response to signals issued by the engine
`control module.
`In use, HC scrubber 10 is incorporated within evaporative
`emissions control system 70, and adsorbs hydrocarbons
`from the bleed emissions flowing out vent port 94 of
`evaporative canister 76. More particularly, as fuel tank 64 is
`subjected to diurnal changes in temperature and/or pressure,
`vapor pressure within fuel tank 64 forces air out of fuel tank
`64. The flow of air carries fuel vapor. The air and fuel vapor
`flow through vapor conduit 74 and into evaporative canister
`76. The air and fuel vapor flow through sorbent media (not
`referenced) contained within evaporative canister 76. The
`sorbent media strips the hydrocarbons from the air flow. The
`treated air flows out vent port 94. However, the air flowing
`out vent port 94 contains bleed emissions. As stated above,
`bleed emissions are believed to result from the hydrocarbon
`heel present in the sorbent material of a purged evaporative
`canister and typically occur during a diurnal cycle. Thus, the
`air flowing out vent port 94 contains hydrocarbon heel-based
`or bleed emissions. The bleed emissions are further removed
`from the flow of air by HC scrubber 10, thereby reducing the
`level of hydrocarbons/bleed emissions emitted by evapora(cid:173)
`tive emissions control system 70 relative to a conventional
`evaporative emissions control system.
`The bleed emissions flow into HC scrubber 10 from vent
`port 94 of evaporative canister 76. More particularly, bleed
`
`6
`emissions from evaporative canister 76 flow out vent port
`94, through vent conduit 78 and into tubular cap end 34 of
`HC scrubber 10. The bleed emission flow through flow
`diffuser 18b which, as shown in FIG. 5, distributes the flow
`5 of bleed emissions B uniformly across the cross-sectional
`area of scrubber element 16 thereby ensuring an even and
`uniform flow of bleed emissions B1 relative to the cross(cid:173)
`sectional area of scrubber element 16. The uniformly(cid:173)
`distributed flow of bleed emissions B1 substantially equally
`10 loads each of passageways 42 with bleed emissions, and
`exposes the bleed emissions to the cumulative surface area
`of passageways 42. Each of passageways 42 are lined with
`or constructed of sorbent material 16a. Thus, the surface
`area of sorbent material 16a to which the bleed emissions are
`15 exposed is maximized, thereby maximizing the capacity of
`scrubber element 16 to adsorb and store hydrocarbons,
`through the uniform distribution of bleed emissions by flow
`diffuser 18b. The cleansed air exits HC scrubber 10 through
`tubular housing end 24, then through air conduit 86 and vent
`20 valve 84, and into the atmosphere.
`HC scrubber 10 is purged through normal operation of
`internal combustion engine 62. At least a portion of the air
`drawn into combustion air intake 66 flows into and through
`HC scrubber 10, and purges HC scrubber 10 of accumulated
`25 hydrocarbons. More particularly, during normal operation of
`engine 62, purge valve 82 is opened thereby fluidly con(cid:173)
`necting purge port 90 to combustion air intake 66 of internal
`combustion engine 62. Combustion air intake 66 is at
`sub atmospheric pressure during normal operation of internal
`30 combustion engine 62. Vent port 94 is in fluid communica(cid:173)
`tion with purge port 90 and, thus, with the subatmospheric
`pressure present at combustion air intake 66. The subatmo(cid:173)
`spheric pressure present at combustion air intake 66, vent
`port 94 and purge port 90 draws fresh air in through vent port
`35 94. More particularly, fresh air is drawn into air conduit 86,
`through vent valve 84 and into tubular housing end 24 of HC
`scrubber 10. The air is drawn into HC scrubber 10 and
`through flow diffuser 18a, which distributes the flow of fresh
`air uniformly across the cross-sectional area of scrubber
`element 16 thereby ensuring an even and uniform flow of
`fresh air through each of passageways 42 as described above
`in regard to flow diffuser 18b. The uniform distribution of
`the fresh air flow relative to the cross-sectional area of
`scrubber element 16 purges the stored bleed emissions/
`45 hydrocarbons from sorbent material 16a which lines each of
`passageways 42. Thus, the efficiency with which scrubber
`element 16 and sorbent material 16a is purged of stored
`hydrocarbons is maximized.
`Similarly, evaporative canister 76 of evaporative emis-
`50 sions control system 70 is purged by the flow of fresh air
`drawn by the vacuum present at combustion air intake 66.
`The air is drawn through HC scrubber 10 and into evapo(cid:173)
`rative canister 76 through vent port 94. The air flows through
`the sorbent material contained within evaporative canister
`55 76 thereby purging same of stored hydrocarbons. The air is
`further drawn by the vacuum out purge port 90, and carries
`with it the hydrocarbons purged from each of evaporative
`canister 76 and HC scrubber 10. The purge air is drawn
`through purge conduit 90 and into combustion air intake 66
`60 of engine 62. The purged air and/or hydrocarbons are drawn
`into combustion air intake 66 where they are mixed into and
`form part of the combustion charge of engine 62. Thus, the
`purged hydrocarbons are burned and consumed by engine
`62.
`Referring now to FIG. 8, a second embodiment of an HC
`scrubber of the present invention is shown. HC scrubber
`110, in general, enables the same amount of sorbent material
`
`65
`
`

`

`US 6,896,852 Bl
`
`10
`
`7
`to be incorporated into a package which occupies less space
`than is occupied by HC scrubber 10. Alternatively, HC
`scrubber 110 enables a substantial increases in the amount
`sorbent material within a housing which occupies approxi(cid:173)
`mately the same space as occupied by HC scrubber 10. More
`particularly, HC scrubber 110 includes housing 112, cap 114,
`scrubber elements 116a and 116b, and flow diffusers 118a,
`118b, 118c and 18d.
`Cap 114 engages housing 112 in an air and fluid tight
`manner, such as, for example, by snap-fitting onto housing
`112 as described above in regard to housing 12 and cap 14
`of HC scrubber 10. Scrubber elements 116a, 116b are each
`disposed within housing 112. Scrubber elements 116a and
`116b are placed in series relative to the flow of bleed
`emissions, such that bleed emissions will flow first through 15
`scrubber element 116a and then through scrubber element
`116b. Flow diffusers 118a, 118b are associated with opposite
`ends of scrubber element 116a, while flow diffusers 118c,
`118d are associated with opposite ends of scrubber element
`116b. Flow diffusers 118a, 118b, 118c, and 118d serve the 20
`same purpose as described above in regard to flow diffusers
`18a and 18b of HC scrubber 10, i.e., the even distribution of
`the flow of air and bleed emissions relative to the cross(cid:173)
`sectional area of scrubber elements 116a and 116b. Each of
`scrubber elements 116a and 116b are spaced apart by
`spacing wall 120 of housing 112. Spacing wall 120 guides
`the flow of bleed emissions and ensures scrubber elements
`116a and 116b are in series relative to the flow of bleed
`emissions. HC scrubber 110 includes cap 114 having tubular
`housing end 124 and tubular cap end 134, which serve as the
`inlet and outlet for the flow of bleed emissions into housing
`112.
`Referring now to FIG. 9, one embodiment of an evapo(cid:173)
`rative emissions assembly of the present invention is shown.
`Generally, evaporative emissions assembly 200 integrates
`into a single housing an evaporative emissions canister and
`an HC scrubber in accordance with the present invention.
`More particularly, evaporative emissions assembly 200
`includes evaporative canister 276 and HC scrubber 210,
`each of which are disposed within housing 299. Evaporative 40
`canister 276 includes purge port 290, vapor inlet port 292
`and vent port 294. Evaporative canister 276 contains sorbent
`material (not shown). Purge port 290 and vapor inlet port
`292 are essentially conventional in design and configuration,
`and are respectively substantially similar in function to 45
`purge port 90 and inlet port 92 as discussed above in regard
`to evaporative canister 76. Vent port 294 forms a passage(cid:173)
`way for the flow of air into and out of evaporative canister
`276. HC scrubber 210 is disposed intermediate and is in fluid
`communication with each of vent port 294 and evaporative 50
`canister 276, such that air flowing into and/or out of evapo(cid:173)
`rative canister 276 through vent port 294 must flow through
`HC scrubber 210. HC scrubber 210 includes scrubber ele(cid:173)
`ment 216 and flow diffusers 218a, 218b (only one shown)
`disposed on opposite ends of scrubber element 216. Scrub- 55
`ber element 216 and flow diffusers 218a, 218b are each
`substantially similar to scrubber element 16 and flow dif(cid:173)
`fusers 18a, 18b, respectively, as discussed above in regard to
`HC scrubber 10.
`In use, fresh air is drawn into and treated air flows out of 60
`evaporative emissions assembly 200 through vent port 294
`of evaporative canister 276. HC scrubber 210 is disposed in
`fluid communication with vent port 294 and evaporative
`canister 276 such that fresh/purge air flowing into and bleed
`emissions flowing from evaporative canister 276 must flow
`through HC scrubber 210. Thus, purge/fresh air entering and
`bleed emission exiting evaporative emissions assembly 200
`
`8
`must flow through scrubber element 216. As bleed emissions
`flow through scrubber element 216, hydrocarbons are
`stripped therefrom by scrubber element 216 in substantially
`the same manner as discussed above in regard to scrubber
`5 element 16 of HC scrubber 10. Further, purge/fresh air is
`selectively drawn through vent port 294 and into evaporative
`canister 276, such as, for example, by a vacuum or a
`combustion air intake fluidly connected to purge port 292.
`The purge/fresh air flows through scrubber element 216
`thereby purging scrubber element 216 of stored hydrocar(cid:173)
`bons in a manner substantially similar to the purging of
`scrubber element 16, as described above in regard to HC
`scrubber 10.
`Referring now to FIG. 10, a second embodiment of an
`evaporative emissions assembly of the present invention is
`shown. Generally, and similarly to evaporative emissions
`assembly 200, evaporative emissions assembly 300 inte(cid:173)
`grates into a single assembly an evaporative emissions
`canister and HC scrubber 310. More particularly, evapora-
`tive emissions assembly 300 includes evaporative canister
`376 and HC scrubber 310. Evaporative canister 376 contains
`sorbent material (not shown), and includes purge port 390,
`vapor inlet port 392 and vent port 394. Purge port 390, vapor
`inlet port 392 and vent port 394 are, respectively, substan-
`25 tially similar in function to purge port 90, inlet port 92 and
`vent port 94 as discussed above in regard to evaporative
`canister 76. HC scrubber 310 includes housing 312, within
`which is disposed scrubber element 316 and flow diffusers
`318a, 318b ( only one shown). Each of housing 312, scrubber
`30 element 316 and flow diffusers 318a, 318b are, respectively,
`substantially similar to scrubber element 16 and flow dif(cid:173)
`fusers 18a, 18b as discussed above in regard to HC scrubber
`10. Elongate conduit 380 fluidly and mechanically intercon(cid:173)
`nects vent port 394 of evaporative cannister 376 and tubular
`35 cap end 334 of HC scrubber 310.
`In use, fresh/purge air is drawn into and treated air flows
`out of evaporative emissions assembly 300 through tubular
`housing end 324 of HC scrubber 310. HC scrubber 310 is
`disposed in fluid communication with vent port 394 of
`evaporative canister 376 such that fresh/purge air flowing
`into and bleed emission flowing from vent port 394 of
`evaporative canister 376 must flow through HC scrubber
`310. Thus, purge/fresh air entering and bleed emission
`exiting evaporative emissions assembly 300 must flow
`through scrubber element 316.
`Bleed emissions flowing from evaporative canister 376
`flow through vent port 394 and into tubular cap end 334 of
`HC scrubber 310. The bleed emissions are channeled
`through scrubber element 316, which strips hydrocarbons
`from the bleed emissions in substantially the same manner
`as discussed above in regard to scrubber element 16 of HC
`scrubber 10. Further, purge/fresh air is selectively drawn
`through tubular housing end 324 into evaporative canister
`376, such as, for example, by a vacuum or a combustion air
`intake fluidly connected to purge port 392. The purge/fresh
`air flows through scrubber element 316, thereby purging
`scrubber element 316 of stored hydrocarbons in a manner
`substantially similar to the purging of scrubber element 16,
`as described above in regard to HC scrubber 10.
`Referring now to FIG. 11, yet another embodiment of an
`HC scrubber of the present invention is illustrated. HC
`scrubber 410 includes housing 412 within which is disposed
`scrubber element 416, each of which are, respectively,
`substantially similar to housing 12 and scrubber element 16
`65 as discussed above in regard to HC scrubber 10. HC
`scrubber 410 further includes electrical connector 452 dis(cid:173)
`posed on the outside surface of housing 412. Electrical
`
`

`

`US 6,896,852 Bl
`
`9
`connector 452 is, for example, integral with or attached to
`housing 412. Further, HC scrubber 410 includes ceramic
`heating elements 454. Heating elements 454 are configured
`as, for example, ceramic disks having electrically conduc(cid:173)
`tive film deposited thereon. Electrical wires 456 are con(cid:173)
`nected to electrical connector 452 and to heating elements
`454 to thereby s