U.S. patent application number 11/271494 was filed with the patent office on 2006-07-20 for engine exhaust system with water entrapment.
Invention is credited to John I. Belisle.
Application Number | 20060157296 11/271494 |
Document ID | / |
Family ID | 36682715 |
Filed Date | 2006-07-20 |
United States Patent
Application |
20060157296 |
Kind Code |
A1 |
Belisle; John I. |
July 20, 2006 |
Engine exhaust system with water entrapment
Abstract
The present disclosure relates to an exhaust treatment system
including a muffler body having a water collection reservoir
defined between inner and outer walls of the muffler body. The
present disclosure also relates to a vertical muffler having an
outlet pipe and a baffle for stabilizing the outlet pipe within the
muffler. The baffle includes an integral necked portion that fits
within a lower end of the outlet pipe. A water collection region is
defined between the necked portion and an inner surface of the
outlet pipe.
Inventors: |
Belisle; John I.; (Hampton,
MN) |
Correspondence
Address: |
MERCHANT & GOULD PC
P.O. BOX 2903
MINNEAPOLIS
MN
55402-0903
US
|
Family ID: |
36682715 |
Appl. No.: |
11/271494 |
Filed: |
November 9, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60626826 |
Nov 9, 2004 |
|
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60655273 |
Feb 15, 2005 |
|
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Current U.S.
Class: |
181/234 |
Current CPC
Class: |
F01N 13/085 20130101;
F01N 13/0097 20140603; F01N 3/005 20130101; Y02T 10/20 20130101;
Y02T 10/12 20130101; F01N 3/035 20130101 |
Class at
Publication: |
181/234 |
International
Class: |
E03D 9/14 20060101
E03D009/14 |
Claims
1. A muffler comprising: a muffler body including an outlet having
an outlet flange; an aftertreatment device mounted within the
muffler body; and the muffler body including inner and outer walls
defining an annular water capturing space located adjacent the
outlet flange.
2. The muffler of claim 1, wherein the inner wall bends outwardly
to close a lower end of the annular water capturing space.
3. The muffler of claim 2, wherein the outer wall defines a drain
hole for draining water that collects within the annular water
capturing space.
4. An exhaust system comprising: a muffler body including an outlet
having an outlet flange; an aftertreatment device mounted within
the muffler body; the muffler body including inner and outer walls
defining an annular water capturing space located adjacent the
outlet flange; and a stack mounted to the outlet flange.
5. The exhaust system of claim 4, wherein the stack includes a
diameter reduced positioned above the water collecting space.
6. The exhaust system of claim 4, wherein the stack includes a jog
providing a stack offset distance equal to at least about one
diameter of the stack.
7. The exhaust system of claim 4, wherein a top end of the stack is
curved at least one third a diameter of the stack.
8. The exhaust system of claim 4, wherein a top end of the stack
includes a mitre cut.
9. A muffler comprising: a muffler body having an inlet and an
outlet; an outlet pipe positioned at the outlet of the muffler
body, the outlet pipe including an upper end and a lower end; an
aftertreatment device mounted within the muffler body beneath the
lower end of the outlet pipe; and a baffle for stabilizing the
lower end of the outlet pipe within the muffler body, the baffle
including an integral inwardly necked portion that fits into the
lower end of the outlet pipe, the inwardly necked portion defining
an interior exhaust flow opening positioned within the outlet pipe,
the inwardly necked portion also defining an annular water
collection region positioned between the necked portion and an
inner surface of the outlet pipe.
10. The muffler of claim 9, wherein the baffle includes an annular
main body that extends outwardly and downwardly from the lower end
of the outlet pipe.
11. The muffler according to claim 9, wherein the lower end of the
outlet pipe defines a drain opening that allows water to drain from
the water collection region to a location outside the outlet
pipe.
12. The muffler according to claim 11, wherein the drain opening is
defined by a slot at the lower end of the outlet pipe.
13. The muffler according to claim 12, wherein a plurality of slots
are defined at the lower end of the outlet pipe.
14. The muffler according to claim 9, wherein the muffler body
includes an inner wall and an outer wall, and wherein the baffle
includes an outer lip that spaces the inner wall from the outer
wall.
15. The muffler according to claim 14, wherein water from the water
collection region drains outwardly along a top side of the baffle
and collects at an annular water collection channel defined by the
outer lip of the baffle, the annular water collection channel being
positioned between the inner and outer walls of the muffler
body.
16. A muffler comprising: a muffler body having an inlet and an
outlet, the muffler body including an inner wall and an outer wall;
an outlet pipe positioned at the outlet of the muffler body, the
outlet pipe including an upper end and a lower end; an
aftertreatment device mounted within the muffler body beneath the
lower end of the outlet pipe; and a one-piece baffle for
stabilizing the lower end of the outlet pipe within the muffler
body, the baffle including an inwardly necked portion that fits
into the lower end of the outlet pipe, the inwardly necked portion
defining an interior exhaust flow opening positioned within the
outlet pipe, the inwardly necked portion also defining an annular
water collection region positioned between the necked portion and
an inner surface of the outlet pipe, the baffle also including an
outer spacer portion that fits between the inner and outer walls of
the muffler body.
17. The muffler of claim 16, wherein the spacer defines an annular
water collection channel positioned between the inner and outer
walls.
18. The muffler of claim 16, wherein the baffle includes an annular
main body that extends outwardly and downwardly from the upwardly
necked portion to the outer spacer portion.
19. The muffler of claim 18, wherein the lower end of the outlet
pipe defines a drain opening that allows water to drain from the
water collection region to a top surface of the annular main body
of the baffle.
20. The muffler of claim 19, wherein the outer spacer portion
defines an outer water collection channel for collecting water that
runs down the top surface of the annular main body of the baffle.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This applications claims the benefit of U.S. Provisional
Patent Application Ser. No. 60/626,826, filed Nov. 9, 2004 and U.S.
Provisional Patent Application Ser. No. 60/655,273, filed Feb. 15,
2005.
TECHNICAL FIELD
[0002] The present invention relates generally to engine exhaust
treatment devices having cores such as catalytic converters or
diesel particulate filters.
BACKGROUND
[0003] To reduce air pollution, engine exhaust emissions standards
have become increasingly more stringent. Aftertreatment devices
have been developed to satisfy these increasingly stringent
standards. For example, catalytic converters have been used to
reduce the concentration of pollutant gases (e.g., hydrocarbons,
carbon monoxide, nitric oxide, etc.) exhausted by engines. U.S.
Pat. No. 5,355,973, which is hereby incorporated by reference,
discloses an example catalytic converter. With respect to diesel
engines, diesel particulate filters have been used to reduce the
concentration of particulate matter (e.g., soot) in the exhaust
stream. U.S. Pat. No. 4,851,015, which is hereby incorporated by
reference, discloses an example diesel particulate filter. Other
example types of aftertreatment devices include lean NOx catalyst
devices, selective catalytic reduction (SCR) catalyst devices, lean
NOx traps, or other device for removing for removing pollutants
from engine exhaust streams.
[0004] Water from rainfall, road spray, or a vehicle washing cycle
can sometimes enter a vehicle exhaust system. Also, under certain
conditions, water vapor from the engine exhaust can condense in the
muffler and tailpipe. When an aftertreatment device such as a
catalytic converter is incorporated into the exhaust system, liquid
water can pose certain problems. In particular, exposure of the
aftertreatment device to water is not desirable because water has a
tendency to adversely affect the catalyst, the substrate (core) on
which the catalyst is applied, and the catalyst substrate mounting
system. Accordingly, it is desirable to inhibit water from wetting
the aftertreatment device.
SUMMARY
[0005] Certain aspects of the present disclosure relate to
structures for inhibiting liquid water from wetting aftertreatment
devices within vehicle exhaust systems.
[0006] A variety of other aspects of the invention are set forth in
part in the description that follows, and in part will be apparent
from the description, or may be learned by practicing the
invention. The aspects of the invention relate to individual
features as well as combinations of features. It is to be
understood that both the foregoing general description and the
following detailed description are exemplary and explanatory only
and are not restrictive of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 illustrates an exhaust system arrangement having
features that are examples of inventive aspects in accordance with
the principles of the present disclosure;
[0008] FIG. 1A is an enlarged detail view of a portion of FIG.
1;
[0009] FIG. 1B is an enlarged detail view of another portion of
FIG. 1;
[0010] FIG. 2 is a left side view of the upper portion of the
exhaust system of FIG. 1;
[0011] FIG. 3 illustrates an alternative exhaust system arrangement
having features that are examples of inventive aspects in
accordance with the principles of the present disclosure;
[0012] FIG. 3A is an enlarged detailed view of the upper portion of
the exhaust system arrangement of FIG. 3;
[0013] FIG. 4 is a cross-sectional view of an adapter that can be
used in yet another alternative exhaust system arrangement and
having features that are examples of inventive aspects in
accordance with the principles of the present disclosure;
[0014] FIG. 5 is a bottom view of the adapter of FIG. 4; and
[0015] FIG. 6 illustrates an alternative exhaust system arrangement
having features that are examples of inventive aspects in
accordance with the principles of the present disclosure.
[0016] While the invention is amenable to various modifications and
alternative forms, specifics thereof have been shown by way of
example in the drawings and will be described in detail below. It
is to be understood, however, that the intention is not to limit
the invention to the particular embodiments described. On the
contrary, the invention is intended to cover all modifications,
equivalents, and alternatives falling within the scope of the
invention as defined by the appended claims.
DETAILED DESCRIPTION
[0017] In the following detailed description, references are made
to the accompanying drawings that depict various embodiments in
which the invention may be practiced. It is to be understood that
other embodiments may be utilized, and structural and functional
changes may be made without departing from the scope of the present
invention.
[0018] FIG. 1 illustrates an exhaust system arrangement including a
vertical muffler 20 and a vertical exhaust stack 22. A diameter
reducer 24 is used to couple the lower end of the stack 22 to the
upper end of the vertical muffler 20. An aftertreatment device 26
(e.g., a catalytic converter) is mounted within the vertical
muffler 20.
[0019] The vertical stack 22 has several features adapted to reduce
the likelihood for water to enter the stack and travel downwardly
to the aftertreatment device 26. For example, as shown in FIG. 1, a
mid region of the stack 22 includes a jog 27 having a first offset
distance O.sub.1. In one embodiment, the offset distance O.sub.1 is
at least equal to the diameter of the stack 22. The jog 27 ensures
that water entering the stack and falling downwardly will impinge
upon wall 28 of the stack prior to reaching the aftertreatment
device 26. When the water impinges on the wall 28, the heat of the
stack often causes evaporation. Otherwise, the water runs
downwardly along the wall of the stack and is captured as described
later in the specification.
[0020] To further protect the aftertreatment device 26 from water
impingement, a top end 29 of the stack 22 includes additional
features for preventing water from entering therein. For example,
in one embodiment, the top end 29 of the stack 22 is curved as
shown in FIG. 2. The curvature at the top end 29 of the stack 22
provides a second offset distance O.sub.2. In one embodiment, the
offset distance O.sub.2 is at least about 1/3 of the diameter of
the stack 22. The curvature causes the top end 29 of the stack 22
to be aligned at an angle .theta. relative to a main vertical
portion 31 of the stack 22. Preferably, the angle .theta. is at
least about 45 degrees. The top end 29 of the stack 22 further
includes a mitre cut 30 configured to prevent water from entering
the stack 22. In one embodiment, the mitre cut 30 is aligned along
a vertical plane such that the perimeter edge of the outlet end of
the stack is aligned within the vertical plane.
[0021] The diameter reducer 24 includes an upper end 40 connected
to the stack 22 and a lower end 42 coupled to the vertical muffler
20. In one non-limiting embodiment, the upper end 40 of the
diameter reducer 24 is welded to the lower end of the stack 22, and
the bottom end 42 of the diameter reducer 24 includes a flange 44
(see FIGS. 1 and 1B) that interfaces with a flange 46 of the
muffler 20. Preferably, a clamp such as a v-band clamp is mounted
around the flanges 44, 46 to couple the diameter reducer 24 and the
muffler 20 together. The diameter reducer 24 also includes a
diameter taper 47 having a radius that is generally smooth.
Preferably, the radius is sufficiently gradual to prevent water
from leaving the surface of the reducer 24 and dripping onto the
aftertreatment device.
[0022] Referring again to FIG. 1, the muffler 20 includes an outer
body 50 having a double wall construction. The outer body 50
includes a cylindrical, main body portion 52 and a tapered end
portion 54. The aftertreatment device 26 is mounted within the main
body portion 52 of the muffler 20.
[0023] The main body portion 52 of the outer body 50 has a double
wall configuration including a generally cylindrical outer wall 53
spaced outwardly from a generally cylindrical inner wall 55. An
annular insulating space 57 is defined between the walls 53, 55.
The space 57 can be filled with air or an insulating material such
as fiberglass, ceramic fiber or other materials have effective
thermal insulating properties. The aftertreatment device 26 is
mounted within the passage defined by the inner wall 55.
[0024] The tapered end portion 54 also has a double wall
configuration defined by an outer wall 59 spaced outwardly from an
inner wall 61. An annular water collection reservoir 63 is defined
between the walls 59, 51. The reservoir 63 includes an open top end
65 and a closed bottom end 67. The closed bottom end 67 is located
at the interface between the main body portion 52 and the tapered
end portion 54. The closed bottom end 67 prevents water from
passing from the reservoir 63 into the insulating space 57 of the
main body portion 52. In certain embodiments, the outer wall 59 can
define one or more drain holes for draining water from the
reservoir 63 to the exterior of the muffler body.
[0025] The outer wall 59 of the tapered end portion 54 includes a
cylindrical lower portion 71, a tapered (e.g., truncated conical)
intermediate portion 73 and a cylindrical upper portion 75. The
lower portion 71 of the outer wall 59 overlaps and is secured to
(e.g., welded) to the outer wall 53 of the main body portion 52.
The top end of the upper portion 75 defines the flange 46 of the
muffler 20.
[0026] The inner wall 61 of the tapered end portion 54 includes a
lower end 81 that encloses the bottom of the reservoir 63. The
lower end 81 is secured (e.g., welded) to the inner and outer walls
55, 53 of the main body portion 52 at locations 83, 85 (see FIG.
1A). The inner wall 61 also includes a tapered (e.g., truncated
conical) intermediate portion 87 that opposes and is generally
parallel to the intermediate portion 73 of the outer wall 59. The
inner wall 61 further includes a generally cylindrical upper end
portion 89. The upper end portion 89 extends in an upright
direction and opposes and is generally parallel to the upper
portion 75 of the outer wall 59. The upper portions 75, 89
cooperate to define the open top end of the reservoir 63.
[0027] In use, water that migrates downwardly within the stack is
captured in the water collection reservoir 63 and accumulates in
the truncated conical portion of the reservoir. The reservoir
prevents water from reaching the aftertreatment device. Preferably,
heat from the exhaust evaporates water from within the reservoir
before the reservoir overflows. In other embodiments, a drain hole
can be provided for draining water from the bottom end of the
reservoir.
[0028] FIG. 3 illustrates an alternative exhaust system arrangement
including a first conduit 122, a second conduit 124, and a third
conduit 126. The second conduit 124 is mounted between the first
and third conduits 122, 126. An aftertreatment device 128 is
mounted within the second conduit 124. Flange interfaces 138 are
provided between the first and second conduits 122,124, and between
the second and third conduits 124,126. Clamps 144 (e.g., V-band
clamps) are provided at the flange interfaces 138 to secure the
conduits 122, 124 and 126 together. The flanges assist in
mechanically coupling the conduits 122, 124, 126 together, and in
sealing the ends of the conduits.
[0029] In the depicted embodiment of FIG. 3, the conduits 122, 124,
and 126 are part of a muffler unit 121. The conduit 122 forms an
inlet section having a flanged end 160 adapted for connection to an
inlet pipe, while the conduit 126 forms an outlet section having a
flanged end 170 adapted for connection to an outlet pipe. The inlet
section includes a diameter expander 161 while the outlet section
includes a diameter reducer 171. A diesel oxidation catalyst 162
(i.e., a catalytic converter) is shown mounted within the conduit
122. The aftertreatment device 128 mounted within the conduit 124
is depicted as a diesel particulate filter. The flange interfaces
138 allow the diesel particulate filter to be easily removed for
servicing (e.g., cleaning).
[0030] The muffler unit 121 has a double-wall construction. For
example, conduit 122 includes an inner conduit 122i surrounded by
an outer conduit 122o. The conduit 124 also has a double-wall
construction including an inner conduit 124i surrounded by an outer
conduit 124o. The conduit 126 further has a double-wall
construction including an inner conduit 126i surrounded by an outer
conduit 126o.
[0031] Annular insulating space 123 is defined between the inner
and outer walls of the muffler. The insulating space 123 can be
filled with only air, or can be filled with an insulating material
such as fiberglass, ceramic fiber or other materials having
effective thermal insulating properties.
[0032] The inner wall 126i of the conduit 126 includes a lower
portion 200, an intermediate portion 202 and an upper portion 204.
The lower portion 200 is generally cylindrical and extends in an
upright direction. The intermediate portion 202 is tapered (e.g., a
truncated cone) and extends radially inwardly from the lower
portion 200. The upper portion 204 is generally cylindrical and
extends in an upright direction from the intermediate portion 202
to the flanged end 170 of the muffler unit 121.
[0033] The outer wall 126o of the conduit 126 includes a lower
portion 206, an intermediate portion 208 and an upper portion 210.
The lower portion 206 is generally cylindrical and is generally
parallel to the lower portion 200 of the inner wall 126i. The
intermediate portion 208 is tapered (e.g., a truncated cone) and is
generally parallel to the intermediate portion 202 of the inner
wall 126i. The upper portion 210 is generally cylindrical and
extends in an upright direction from the intermediate portion 208
to the flanged end 170 of the muffler unit 121. The upper portion
210 of the outer wall 126o is preferably secured (e.g., welded) to
the upper portion 204 of the inner wall 126i.
[0034] As shown at FIG. 3A, the flanged end 170 is defined by
member 191 that is secured to the outer wall 126o. The member 191
also includes a generally cylindrical portion 173 that extends
downwardly from the flanged end 170. A lower end 175 of the
cylindrical portion 173 is secured (e.g., welded) to the exterior
of the outer wall 126o. An annular water capturing space 177 is
defined between the cylindrical portion 173 and the wall 126o. A
top end 179 of the space 177 is open, while a bottom end 181 of the
space 177 is closed by the wall 126o. The cylindrical portion 173
defines one or more drain holes 183 for draining water from the
space 177.
[0035] As described above, the aftertreatment device 26 is
identified as a catalytic converter. However, it will be
appreciated that structures in accordance with the principles of
the present disclosure can be used to inhibit water from wetting a
variety of different types of aftertreatment devices. Example
aftertreatment devices include catalytic converters, diesel
particulate filters, lean NOx catalyst devices, selective catalytic
reduction (SCR) catalyst devices, lean NOx traps, or other devices
for removing pollutants from the exhaust stream.
[0036] Catalytic converters, also known as Diesel Oxidation
Catalysts or DOC's, are commonly used to convert carbon monoxides
and hydrocarbons in the exhaust stream into carbon dioxide and
water. Diesel particulate filters are used to remove particulate
matter (e.g., carbon based particulate matter such as soot) from an
exhaust stream. Lean NOx catalysts are catalysts capable of
converting NOx to nitrogen and oxygen in an oxygen rich environment
with the assistance of low levels of hydrocarbons. For diesel
engines, hydrocarbon emissions are too low to provide adequate NOx
conversion, thus hydrocarbons are required to be injected into the
exhaust stream upstream of the lean NOx catalysts. SCR's are also
capable of converting NOx to nitrogen and oxygen. However, in
contrast to using hydrocarbons for conversion, SCR's use reductants
such as urea or ammonia that are injected into the exhaust stream
upstream of the SCR's. NOx traps use a material such as barium
oxide to absorb NOx during lean bum operating conditions. During
fuel rich operations, the NOx is desorbed and converted to nitrogen
and oxygen by catalysts (e.g., precious metals) within the
traps.
[0037] Diesel particulate filter substrates can have a variety of
known configurations. An exemplary configuration includes a
monolith ceramic substrate having a "honey-comb" configuration of
plugged passages as described in U.S. Pat. No. 4,851,015 that is
hereby incorporated by reference in its entirety. Wire mesh
configurations can also be used. In certain embodiments, the
substrate can include a catalyst. Exemplary catalysts include
precious metals such as platinum, palladium and rhodium, and other
types of components such as base metals or zeolites.
[0038] For certain embodiments, diesel particulate filters can have
a particulate mass reduction efficiency greater than 75%. In other
embodiments, diesel particulate filters can have a particulate mass
reduction efficiency greater than 85%. In still other embodiments,
diesel particulate filters can have a particulate mass reduction
efficiency equal to or greater than 90%. For purposes of this
specification, the particulate mass reduction efficiency is
determined by subtracting the particulate mass that enters the
filter from the particulate mass that exits the filter, and by
dividing the difference by the particulate mass that enters the
filter.
[0039] Catalytic converter substrates can also have a variety of
known configurations. Exemplary configurations include substrates
defining channels that extend completely therethrough. Exemplary
catalytic converter configurations having both corrugated metal and
porous ceramic substrates/cores are described in U.S. Pat. No.
5,355,973, that is hereby incorporated by reference in its
entirety. The substrates preferably include a catalyst. For
example, the substrate can be made of a catalyst, impregnated with
a catalyst or coated with a catalyst. Exemplary catalysts include
precious metals such as platinum, palladium and rhodium, and other
types of components such as base metals or zeolites.
[0040] In one non-limiting embodiment, a catalytic converter can
have a cell density of at least 200 cells per square inch, or in
the range of 200-400 cells per square inch. A preferred catalyst
for a catalytic converter is platinum with a loading level greater
than 30 grams/cubic foot of substrate. In other embodiments the
precious metal loading level is in the range of 30-100 grams/cubic
foot of substrate. In certain embodiments, the catalytic converter
can be sized such that in use, the catalytic converter has a space
velocity (volumetric flow rate through the DOC/volume of DOC) less
than 150,000/hour or in the range of 50,000-150,000/hour.
[0041] In the depicted embodiments, V-band clamps are used to hold
the components together. It will be appreciated that in other
embodiments, any number of different types of pipe clamps or
fasteners could be used to fasten the parts together. Also, the
various aspects of the present disclosure are also applicable to
exhaust components (e.g., mufflers) that are not adapted to be
readily disassembled.
[0042] Referring now to FIGS. 4 and 5, another alternative
embodiment of a device used to inhibit water from wetting
aftertreatment devices within vehicle exhaust systems is
illustrated. The alternative embodiment includes an adapter 300
that mounts between a vertical stack and a muffler component
containing an aftertreatment device. In one embodiment, the adapter
300 can be used as an outlet section for a catalytic converter
muffler in much the same way as the outlet section provided by
conduit 126 of FIG. 3. The aftertreatment device can include, for
example, a catalytic converter or a diesel particulate filter.
[0043] The adapter 300 includes a housing 302 and a cap 304. A
conduit 306 extends through the housing 302. A first end 308 of the
conduit 306 is configured to interconnect to a pipe/conduit such as
a muffler stack and a second end 310 of the conduit 306 is
interconnected to the cap 304. The cap 304 is configured to mount
or interconnect to another exhaust system component such as a
muffler section containing an aftertreatment device.
[0044] The adapter 300 in the illustrated embodiment further
includes a water entrapment ring or piece 312 positioned within the
conduit 306. The water entrapment piece 312 has a ring shape that
defines an open central region 328 (FIG. 5). The water entrapment
piece 312 provides a seal 314 between the water entrapment piece
312 and an interior surface 316 of the conduit 306. A first annular
reservoir or water capturing space 318 is defined between a shaped
region 320 of the water entrapment piece 312 and the interior
surface 316 of the conduit 306. When water enters the conduit 306
of the adapter 300 (typically running down the interior surface 316
of the conduit), the water is captured or collected within the
first annular reservoir 318 defined by the water entrapment piece
312. The water entrapment piece 312 is constructed to permit
exhaust to pass through the open central region 328, yet capture
water within the first annular reservoir 318.
[0045] A second annular reservoir 322 is located between an
exterior 324 of the conduit 306 and the housing 302. The second
reservoir 322 has a bottom 326 defined by the cap 304. An aperture
or hole 329 formed in the conduit 306 provides fluid communication
between the first reservoir 318 and the second reservoir 322. In
use, the water entrapment piece 312 captures water within the first
reservoir 318. The collected water then drains through the hole 329
in the conduit and into the second reservoir 322. During operation
of the aftertreatment device, the cap 304 becomes hot. Any water
that has collected within the second reservoir 322 thereby heats
and evaporates within the second reservoir 322. The adapter 300
shown in FIGS. 4 and 5 eliminates water drainage along exterior
surfaces of the vehicle exhaust system by evaporating the water
within the second reservoir. However, in other embodiments, a drain
hole may be provided through the outer wall of the adapter 300 for
draining water that collects at the second reservoir 322.
[0046] Referring now to FIG. 6, another alternative embodiment of a
device used to inhibit water from wetting aftertreatment devices
within vehicle exhaust systems is illustrated. The muffler 400
includes a lower inlet pipe 402 and an upper outlet pipe 404. A
catalytic converter and diesel particulate filter 408 are mounted
within the muffler body between the inlet pipe 402 and the outlet
pipe or tube 404. The outlet pipe 404 includes an upper end 410
adapted for connection to an exhaust conduit such as a tail pipe,
and a lower end 412. The lower end 412 is supported by an annular
baffle 414. The baffle 414 includes a central, upwardly necked
portion 416 that defines a central exhaust flow opening 418. The
upwardly necked portion 416 is fit within the inside of the lower
end 412 of the outlet tube 404. The upper edge 420 of the upwardly
necked portion 416 is angled inwardly such that a first water
collection reservoir 422 is defined between the necked portion 416
and the interior surface 424 of the outlet tube 404. Slots 426 are
provided at the lower end 412 of the outlet tube 404 to allow water
collected in the collection reservoir 422 to drain out of the first
water collection reservoir 422 through the slots 426. The baffle
414 also includes a main body 427 having a top surface 428 that
extends radially outwardly from the necked portion 416. The top
surface 428 is angled downwardly relative to the lower end 412 of
the outlet pipe 404. A lip 430 is provided at the outer edge 432 of
the surface 428. The lip 430 defines a second water collection
reservoir 434 (e.g., an annular trough or channel) that functions
to collect water that drains through the slots 426 and runs
downwardly along the surface 428 to lip 430. A drain hole 436 can
be provided through the outer wall 438 of the muffler to drain
water from the second water collection reservoir 434. The lip 430
also functions as a spacer for spacing an inner body 440 of the
muffler 400 from the outer wall 438 of the muffler 400. The spacer
functions to stabilize the inner body 440 relative to the outer
body 442 and to center the inner body 440 within the outer body
442. The inner body 440 can be secured (e.g., welded) to the baffle
414 adjacent an inner portion of the outer lip 430 of the baffle
414. The outer body 442 can be secured (e.g., welded) to the baffle
414 adjacent an outer portion of the outer lip 430. In the depicted
embodiment of FIG. 6, the baffle 414 has a one-piece construction
in which the necked portion 416 and the lip 430 are integral with
the main body 427. The term "integral" means directly connected by
a unitary connection without any intermediate seams on joints.
[0047] The configuration provides a number of advantages. For
example, the configuration of the baffle 414 with the relatively
large necked opening 418 inset within the outlet tube 404 helps to
minimize back pressure. Back pressure is also minimized because the
baffle 414 and the inner body 440 cooperate to direct flow from the
diesel particulate filter 408 to the outlet tube 404 in a
relatively smooth manner. The baffle 414 also provides a water
collection function at two places. First, water is collected at the
inner surface 424 of the outlet tube 404. Second, water is
collected at the inner surface 444 of the outer muffler body 442.
The baffle 414 also provides the function of directing the flow of
water from the first collection area 422 to the second collection
area 434. The baffle 414 further functions to stabilize the inner
body 440 relative to the outer muffler body 442, and to stabilize
the lower end 412 of the outlet tube 404 relative to the inner and
outer muffler bodies 440, 442.
[0048] The above specification and examples provide a complete
description of the manufacture and use of the invention. Since many
embodiments of the invention can be made without departing from the
spirit and scope of the invention, the invention resides in the
claims hereinafter appended.
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