U.S. patent application number 11/301219 was filed with the patent office on 2010-05-06 for catalyst device for a marine engine which is generally tubular with a rim portion.
This patent application is currently assigned to Brunswick Corporation. Invention is credited to Derric Drake, Christopher J. Luckett, William C. Martin, Matthew L. Mauk, Loren Powers, Stephen M. Seymour, Brian R. White, Scott Williams.
Application Number | 20100112878 11/301219 |
Document ID | / |
Family ID | 42131974 |
Filed Date | 2010-05-06 |
United States Patent
Application |
20100112878 |
Kind Code |
A1 |
White; Brian R. ; et
al. |
May 6, 2010 |
Catalyst device for a marine engine which is generally tubular with
a rim portion
Abstract
A catalyst system for a marine engine incorporates a catalyst
device within a housing structure. The catalyst device has a rim
portion that is disposed within first and second flange surfaces of
first and second housing structures. A gasket is provided which is
configured to have an opening that allows the rim portion of the
catalyst device to be constrained between the first and second
flange portions but not between the gasket and either of the first
and second flange surfaces.
Inventors: |
White; Brian R.;
(Stillwater, OK) ; Powers; Loren; (Stillwater,
OK) ; Mauk; Matthew L.; (Stillwater, OK) ;
Williams; Scott; (Edmond, OK) ; Martin; William
C.; (Edmond, OK) ; Seymour; Stephen M.;
(Yukon, OK) ; Drake; Derric; (Stillwater, OK)
; Luckett; Christopher J.; (Stillwater, OK) |
Correspondence
Address: |
WILLIAM D. LANYI
MERCURY MARINE, W6250 PIONEER ROAD P.O. BOX 1939
FOND DU LAC
WI
54936-1939
US
|
Assignee: |
Brunswick Corporation
|
Family ID: |
42131974 |
Appl. No.: |
11/301219 |
Filed: |
December 12, 2005 |
Current U.S.
Class: |
440/89H |
Current CPC
Class: |
F01N 2590/02 20130101;
F01N 13/008 20130101; F01N 3/2842 20130101; F01N 13/105
20130101 |
Class at
Publication: |
440/89.H |
International
Class: |
F01N 3/28 20060101
F01N003/28; F01N 13/00 20100101 F01N013/00; B63H 21/14 20060101
B63H021/14 |
Claims
1-2. (canceled)
3. An exhaust system for a marine engine, comprising: a first
catalyst device comprising a first catalyst material disposed
within a first catalyst structure, said first catalyst structure
having a first generally tubular portion, said first generally
tubular portion having a first central axis; a first rim portion
extending from an end of said first generally tubular portion, said
first rim portion being disposed in a first plane which is
generally perpendicular to said first central axis; a first housing
structure configured to direct an exhaust gas away from said marine
engine, said first housing structure having a first flange surface;
a second housing structure configured to direct said exhaust gas
away from said first housing structure, said second housing
structure having a second flange surface; a gasket, said first and
second housing structures being configured to be attached together
with said gasket being disposed between said first and second
flange surfaces, said gasket having a first opening formed through
its thickness, said first opening being configured to receive said
first rim portion therein; wherein said gasket is engaged by said
first and second flange surfaces on axially distally opposite sides
of said gasket without said first rim portion therebetween; said
first rim portion is disposed within said first opening and in
direct contact with said first and second flange surfaces when said
first and second flange surfaces are attached together; said first
rim portion is engaged by said first and second flange surfaces at
a first engagement location spaced radially outwardly of said first
central axis by a first radial distance; said gasket is engaged by
said first and second flange surfaces at a second engagement
location spaced radially outwardly of said first central axis by a
second radial distance; and said second radial distance is greater
than said first radial distance.
4. The exhaust system of claim 3, further comprising: a second
catalyst device comprising a second catalyst material disposed
within a second-catalyst structure, said second catalyst structure
having a second generally tubular portion, said second generally
tubular portion having a second central axis; and a second rim
portion extending from an end of said second generally tubular
portion, said second rim portion being disposed in a second plane
which is generally perpendicular to said second central axis.
5. The exhaust system of claim 4, wherein: said gasket has a second
opening formed through its thickness, said second opening being
configured to receive said second rim portion therein.
6. The exhaust system of claim 5, wherein: said second rim portion
is disposed within said second opening and in direct contact with
said first and second flange surfaces when said first and second
flange surfaces are attached together.
7. The exhaust system of claim 6, further comprising: a third
catalyst device comprising a third catalyst material disposed
within a third-catalyst structure, said third catalyst structure
having a third generally tubular portion, said third generally
tubular portion having a third central axis; and a third rim
portion extending from an end of said third generally tubular
portion, said third rim portion being disposed in a third plane
which is generally perpendicular to said third central axis.
8. The exhaust system of claim 7, wherein: said gasket has a third
opening formed through its thickness, said third opening being
configured to receive said third rim portion therein.
9. The exhaust system of claim 8, wherein: said third rim portion
is disposed within said third opening and in direct contact with
said first and second flange surfaces when said first and second
flange surfaces are attached together.
10. The exhaust system of claim 9, wherein: said first, second and
third planes are coplanar with each other and said first, second
and third central axes are parallel with each other.
11-12. (canceled)
13. An exhaust system for a marine engine, comprising: a plurality
of catalysts, each of said plurality of catalysts comprising a
catalyst material disposed within a catalyst structure, each of
said catalyst structures having a generally tubular portion, each
of said generally tubular portions having a central axis, each of
said plurality of catalysts further comprising a rim portion
extending from an end of said generally tubular portion, said rim
portion being disposed in a rim plane which is generally
perpendicular to said central axis; a first housing structure
configured to direct an exhaust gas away from said marine engine,
said first housing structure having a first flange surface; a
second housing structure configured to direct said exhaust gas away
from said first housing structure, said second housing structure
haying a second flange surface; a gasket, said first and second
housing structures being configured to be attached together with
said gasket being disposed between said first and second flange
surfaces, said gasket having a plurality of openings formed through
its thickness, each of said plurality of openings being configured
to receive one of said rim portions of said plurality of catalysts
therein; wherein said gasket is engaged by said first and second
flange surfaces on axially distally opposite sides of said gasket
without said rim portions therebetween; each of said rim portions
of said plurality of catalysts is disposed within a preselected one
of said plurality of openings; each of said rim portions is engaged
by said first and second flange surfaces at a respective first
engagement location spaced radially outwardly of a respective
central axis by a first radial distance; said gasket is engaged by
said first and second flange surfaces at a respective second
engagement location spaced radially outwardly of the respective
central axis by a second radial distance; and said second radial
distance is greater than said first radial distance.
14. The exhaust system of claim 13, wherein: each of said central
axes of each of said generally tubular portions being disposed in a
common alignment plane which is generally perpendicular to said rim
plane.
15. The exhaust system of claim 14, wherein: said plurality of
catalysts is disposed in serial fluid communication with said first
and second housing structures.
16. An exhaust system for a marine engine, comprising: a plurality
of catalysts, each of said plurality of catalysts comprising a
catalyst material disposed within a catalyst structure, each of
said catalyst structures having a generally tubular portion, each
of said generally tubular portions having a central axis, each of
said plurality of catalysts further comprising a rim portion
extending from an end of said generally tubular portion, said rim
portion being disposed in a rim plane which is generally
perpendicular to said central axis; a first housing structure
configured to direct an exhaust gas away from said marine engine,
said first housing structure having a first flange surface; a
second housing structure configured to direct said exhaust gas away
from said first housing structure, said second housing structure
having a second flange surface; a gasket, said first and second
housing structures being configured to be attached together with
said gasket being disposed between said first and second flange
surfaces, said gasket having a plurality of openings formed through
its thickness, each of said plurality of openings being configured
to receive one of said rim portions of said plurality of catalysts
therein, each of said rim portions of said plurality of catalysts
being disposed within a preselected one of said plurality of
openings; wherein: said gasket is engaged by said first and second
flange surfaces on axially distally opposite sides of said gasket
without said rim portions therebetween; each of said rim portions
is engaged by said first and second flange surfaces at a respective
first engagement location spaced radially outwardly of the
respective central axis by a first radial distance; said gasket is
engaged by said first and second flange surfaces at a respective
second engagement location spaced radially outwardly of the
respective central axis by a second radial distance; and said
second radial distance is greater than said first radial
distance.
17. The exhaust system of claim 16, wherein: each of said central
axes of each of said generally tubular portions being disposed in a
common alignment plane which is generally perpendicular to said rim
plane.
18. The exhaust system of claim 17, wherein: said plurality of
catalysts is disposed in serial fluid communication with said first
and second housing structures.
19. The exhaust system of claim 3, wherein: said first rim portion
extends to said first radial distance to reach said first
engagement location; and said first rim portion does not extend to
said second radial distance and does not reach said second
engagement location.
20. The exhaust system of claim 13, wherein: each of said rim
portions extends to the respective said first radial distance to
reach the respective said first engagement location; and each said
rim portion does not extend to the respective said second radial
distance and does not reach the respective said second engagement
location.
21. The exhaust system of claim 16, wherein: each of said rim
portions extends to the respective said first radial distance to
reach the respective said first engagement location; and each of
said rim portions does not extend to the respective said second
radial distance and does not reach the respective said second
engagement location.
Description
CROSS REFERENCE TO CO-PENDING PATENT APPLICATION
[0001] This patent application is a member of a family of
co-pending and commonly owned patent applications which were all
filed on ______, 2005. This family includes patent application
(M09964) which was filed by White (Ser. No. ______), patent
application (M09966) which was filed by White (Ser. No. ______),
patent application (M09967) which was filed by Burk et al (Ser. No.
______), patent application (M09968) which was filed by White et al
(Ser. No. ______), patent application (M09969) which was filed by
White et al (Ser. No. ______), patent application (M09971) which
was filed by White (Ser. No. ______), patent application (M09972)
which was filed by White et al (Ser. No. ______), patent
application (M09974) which was filed by White (Ser. No. ______),
patent application (M09976) which was filed by White (Ser. No.
______).
FIELD OF THE INVENTION
[0002] The present invention is generally related to a catalyst
device for a marine engine and, more particularly, to a catalyst
device that is generally tubular and has a rim portion attached to
one end of the generally tubular portion.
DESCRIPTION OF THE RELATED ART
[0003] Those skilled in the art of internal combustion engines are
aware of many types of catalyst systems that are available to
improve exhaust emissions emitted by the engines.
[0004] U.S. Pat. No. 4,848,082, which issued to Takahashi et al. on
Jul. 18, 1989, describes an exhaust gas purifying device for a
marine engine. A catalyst exhaust system for an outboard motor is
described. A throttle control arrangement is incorporated for
assuring rapid heating of the catalyst to its operating
temperature.
[0005] U.S. Pat. No. 4,900,282, which issued to Takahashi et al. on
Feb. 13, 1990, describes an exhaust gas purifying device for a
marine engine. A catalytic exhaust system for a marine outboard
drive is described wherein the catalyzer material is supported by a
heat conductive bracket and the bracket is cooled by a cooling
jacket that is supplied with coolant from the engine cooling
jacket. In one embodiment, the water jacket is cooled both
internally and externally by delivering water from the cooling
jacket into the exhaust system to impinge upon a wall of the
cooling jacket.
[0006] U.S. Pat. No. 5,133,185, which issued to Gilbreath et al. on
Jul. 28, 1992, describes an anti-moisture device for engine exhaust
systems. The device is intended to remove moisture droplets from an
interior surface of a duct, characterized by an outer edge secured
to the interior surface of the duct, an inner edge surrounding an
opening, and a connecting wall between the outer edge and the inner
edge. The inner edge of the anti-moisture device is positioned
closer to a downstream end of the duct than the outer edge whereby
the connecting wall is positioned at an angle relative to the
interior surface of the duct. Moisture droplets traveling upstream
will be caught between the connecting wall and the interior surface
of the duct, on the downstream side of the device.
[0007] U.S. Pat. No. 5,167,934, which issued to Wolf et al. on Dec.
1, 1992, describes a catalyzer installation for boat engines and a
method for catalytic exhaust gas cleaning. The invention is
intended for use in boat engines and the catalyzer is subdivided
into a reduction part location upstream in the exhaust gas line and
an oxidation part located coaxially downstream after it. An
intermediate space is located between the reduction and oxidation
parts. Both catalyzer parts are surrounded by a preferably
cylindrical, water cooled casing and the casing has a downstream
secondary air inlet to which a secondary air blower can be
connected, the secondary air separating the very hot catalyzer from
the double walled, water cooled casing and, in particular, flowing
around the oxidation catalyzer part in counterflow for air
preheating so that the air preheating in this manner is passed
through the intermediate space into the oxidation part.
[0008] U.S. Pat. No. 5,203,167, which issued to Lassanske et al. on
Apr. 20, 1993, describes a marine propulsion device internal
combustion engine and method for making the same. The propulsion
device comprises a driveshaft housing, a propeller shaft rotatably
supported by the driveshaft housing, an internal combustion engine
drivingly connected to the propeller shaft, the engine including a
cylinder block defining a cylinder having an exhaust port, and
defining an exhaust outlet, and an exhaust passage between the
exhaust port and the exhaust outlet, an exhaust catalyst apparatus
mounted on the cylinder block, the apparatus including a tongue
extending into the cylinder block exhaust passage and dividing the
cylinder block exhaust passage into an upstream portion
communicating with the exhaust port and a downstream portion
communicating with the exhaust outlet. The apparatus includes an
exhaust passage communicating between the upstream portion and the
downstream portion. The catalyst is located in the apparatus
exhaust passage.
[0009] U.S. Pat. No. 5,212,949, which issued to Shiozawa on May 25,
1993, describes an exhaust gas cleaning system for a marine
propulsion unit. It is intended for use with a watercraft engine. A
plurality of horizontally positioned exhaust ports are located
within an engine cylinder head. An exhaust manifold communicates
with each of the exhaust ports at a first end and forms a gas
collecting pipe at its second end. The second end of the gas
collecting pipe is positioned above the exhaust ports. A generally
horizontally positioned exhaust pipe extends from the second end of
the gas collecting pipe and continues in a rearward direction.
Means are provided for introducing coolant from the engine into the
rearwardly extending portion of the exhaust pipe.
[0010] U.S. Pat. No. 5,306,185, which issued to Lassanske et al. on
Apr. 26, 1994, describes catalytic elements for marine propulsion
devices. A marine propulsion device comprising a propulsion unit
including a propeller shaft, a housing including an exhaust gas
inlet and an exhaust gas outlet, a catalytic element supported in
the housing for reorientation from a first orientation to a second
orientation different from the first orientation, and structure for
reorienting the element from the first orientation to the second
orientation is described.
[0011] U.S. Pat. No. 5,324,217, which issued to Mineo on Jun. 28,
1994, describes an exhaust system for a small boat. It includes a
water trap device for precluding water entering the exhaust system
if the watercraft becomes inverted from entering the engine through
the exhaust system. Coolant from the engine is delivered to a
cooling jacket that encircles the entire exhaust system and is
introduced into the exhaust gases downstream of the water trap so
that in the event of inversion and righting the engine coolant will
also not enter the exhaust system. This also provides protection
for catalyzers in the exhaust system.
[0012] U.S. Pat. No. 5,408,827, which issued to Holtermann et al.
on Apr. 25, 1995, describes a marine propulsion device with
improved catalyst support arrangement. An internal combustion
engine includes an exhaust port, an exhaust conduit communicating
with the exhaust port and having an inner surface, the conduit
including first and second conduit portions having respective ends,
the first and second conduit portions being connected end to end, a
catalyst which is located within the conduit and which includes
catalytic material and a sleeve surrounding the catalytic material,
wherein the sleeve has a length and an outer surface spaced from
the inner surface of the conduit along substantially the entire
length of the sleeve. The sleeve has a rigid, radially outwardly
extending flange captured between the ends of the conduit portions,
and a flexible gasket between the flange and the end of one of the
conduit portions.
[0013] U.S. Pat. No. 5,425,232, which issued to Holtermann on Jun.
20, 1995, describes a marine propulsion device with means for
supplying secondary air to a catalytic converter. The marine
propulsion device comprises a combustion chamber, an exhaust
passage, an air pump and a three-way catalytic converter. The air
pump pumps air into the exhaust passage at or immediately upstream
of the catalytic converter. By this construction the internal
combustion engine can be run slightly rich, but the catalytic
converter will see a close to stoichiometric mixture so that the
pollutants in the exhaust stream can be oxidized or reduced
appropriately since the catalytic converter will be able to operate
as a three-way catalytic converter.
[0014] U.S. Pat. No. 5,433,634, which issued to Nakayama et al. on
Jul. 18, 1995, describes an exhaust treatment for an outboard
motor. The exhaust gases are normally discharged to the atmosphere
at a point below the level of the body of water in which the
watercraft is operating. A catalyst bed is provided in the exhaust
system and the catalyst bed is protected from damage by pumping
water from the exhaust conduit in response to certain conditions.
These conditions may be either rapid deceleration of the engine or
watercraft, stopping of the engine, or any of the combination of
sensed factors. The water is pumped by a water pump which is
positioned either in the outboard drive or in the hull of an
associated watercraft. The pumping of water is initiated for only a
predetermined time and until the sensed condition no longer is
existent.
[0015] U.S. Pat. No. 6,053,785, which issued to Kato et al. on Apr.
25, 2000, describes an exhaust system and control for a marine
propulsion engine. An outboard motor exhaust system and control for
insuring good running and effective exhaust gas silencing and
treatment is provided. The system includes a very compact exhaust
system that includes an expansion chamber formed beneath the
exhaust guide plate and to which the exhaust gases are delivered
and removed at optimal locations. Furthermore, a feedback control
employing a combustion condition sensor is employed along with a
catalyst in the exhaust. Sensors are provided upstream and
downstream of the catalyst to insure that it is operating at
optimum conditions.
[0016] U.S. Pat. No. 6,116,022, which issued to Woodward on Sep.
12, 2000, describes a catalytic reactor for marine applications.
The reactor for an internal combustion engine has a cooling jacket
surrounding multiple catalyst elements. A thermal barrier layer is
formed between the catalyst elements and the cooling jacket to
prevent overcooling of the catalyst elements. The thermal barrier
layer can be formed from insulating elements such as fibrous
material, a plurality of annular rings disposed around the catalyst
elements, a corrugated layer, or can be formed by an empty
space.
[0017] U.S. Pat. No. 6,368,726, which issued to Holpp et al. on
Apr. 9, 2002, describes a honeycomb body configuration. It includes
a honeycomb body with a fluid inlet side and a fluid outlet side.
The honeycomb body is formed of at least partially structured sheet
metal layers which form channels through which a fluid can flow.
The honeycomb body is surrounded by an inner tubular jacket and an
outer tubular jacket provided concentrically in relation thereto.
The inner tubular jacket is configured as a corrugated hose in at
least one axial subregion thereof. The inner tubular jacket has at
least one further axis subregion which lies smoothly against the
honeycomb body. The corrugated subregion and the outer tubular
jacket are connected at least in a longitudinal partial region of
the corrugated subregion.
[0018] U.S. Pat. No. 6,639,193, which issued to Schaper on Oct. 28,
2003, describes a method and apparatus for end-surface connection
of a carrier matrix of a honeycomb body by a joining technique. It
relates in particular to a catalyst carrier body. The matrix is
disposed in a tubular jacket and is laminated and/or wound from at
least partially structured sheet metal foils or layers. The end
surface of the honeycomb body is at least partially heated with the
aid of a surface inductor having induction coils.
[0019] U.S. Pat. No. 6,660,235, which issued to Holpp et al. on
Dec. 9, 2003, describes a catalyst carrier configuration for
installation close to an engine. It includes a housing and at least
one catalyst carrier body disposed in the housing. The catalyst
carrier body has partition walls defining a plurality of passages
for an exhaust gas. A flange surrounds the catalyst carrier body
and extends radially outwards from the catalyst carrier body. The
flange has a second that extends at least partially into an outer
wall of the housing and can be disposed between a cylinder head and
a manifold of an internal combustion engine. The catalyst carrier
configuration can be mounted close to an internal combustion
engine. A structural unit having at least two catalyst carrier
configurations and an exhaust system are also provided.
[0020] U.S. Pat. No. 6,740,178, which issued to Kurth et al. on May
25, 2004, describes a method for producing a centered honeycomb
body. The method includes forming a honeycomb body by stacking
and/or winding layers of steel sheet containing chromium and
aluminum resulting in the honeycomb body having channels through
which a fluid can flow. The honeycomb body is introduced into a
tubular jacket.
[0021] U.S. Pat. No. 6,799,422, which issued to Westerbeke et al.
on Oct. 5, 2004, describes an emission control method. It is
intended for use with a fixed speed internal combustion engine and
includes injecting a controlled flow of air into the exhaust
between a first catalyst bed adapted to reduce hydrocarbon and
nitrogen oxide emissions and a second catalyst bed adapted to
reduce carbon monoxide emissions.
[0022] The patents described above are hereby expressly
incorporated by reference in the description of the present
invention.
SUMMARY OF THE INVENTION
[0023] An exhaust system for a marine engine made in accordance
with a preferred embodiment of the present invention comprises a
first catalyst device comprising a first catalyst material disposed
within a first housing structure. The first housing structure has a
first generally tubular portion which, in turn, has a first axis. A
first rim portion extends from an end of the first generally
tubular portion and is disposed in a plane which is generally
perpendicular to the first central axis.
[0024] A first housing structure is configured to direct exhaust
gas away from the marine engine and is provided with a first flange
surface. A second housing structure is configured to direct exhaust
gas away from the first housing structure and has a second flange
surface. A gasket is provided and the first and second housing
structures are configured to be attached together with the gasket
being disposed between the first and second flange surfaces. The
gasket has a first opening formed through its thickness and the
first opening is configured to receive the rim portion therein. The
rim portion is not compressed between the gasket and either the
first or second flange surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The present invention will be more fully and completely
understood from a reading of the description of the preferred
embodiment in conjunction with the drawings, in which:
[0026] FIG. 1 is a side view of a marine engine which is partially
sectioned to show internal portions of the exhaust system;
[0027] FIG. 2 is an isometric partially sectioned view of the port
and starboard exhaust components;
[0028] FIG. 3 is a section view of the port exhaust system of a
marine engine;
[0029] FIG. 4 is a partially sectioned isometric view of the device
shown in FIG. 3;
[0030] FIG. 5 is an exploded isometric view of the port side
exhaust system of the present invention;
[0031] FIG. 6 is a section view of the port side exhaust system of
a marine engine; and
[0032] FIG. 7 is an alternative exhaust system using an oblong
catalyst device.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] Throughout the description of the preferred embodiment of
the present invention, like components will be identified by like
reference numerals. In the following description of various
embodiments of the present invention, certain configurations will
be described and illustrated as having three catalyst devices used
together as a system. It should be clearly understood that the
catalyst devices can alternatively be combined together in systems
comprising less than or greater than this number. In addition, it
should also be clearly understood that certain embodiments of the
present invention can comprise a single catalyst device. All of
these alternative configurations are described below in relation to
an exemplary engine arrangement. In addition, it should be
understood that a catalyst system made in accordance with a
preferred embodiment of the present invention, when used in
conjunction with a V-type engine, would typically be provided at
both sides, or cylinder banks, of the engine.
[0034] FIG. 1 shows a marine engine 10 within the structure of a
marine vessel 12. Although not shown in FIG. 1, the crankshaft of
the engine 10 is supported for rotation about a horizontal axis and
attached in torque transmitting relation with a driveshaft that
extends through the transom 14 to provide motive power to a marine
propulsion drive (not shown in FIG. 1). The marine engine 10 has a
plurality of exhaust ports 20 configured to conduct exhaust gas
from a plurality of cylinders within the structure of the engine. A
first exhaust conduit 22 is disposed in fluid communication with
the plurality of exhaust ports 20. The first exhaust conduit 22
performs the function of an exhaust manifold which receives the
exhaust gas from the plurality of exhaust ports 20 and directs it
away from the engine 10. A plurality of catalyst devices 23-25 is
disposed in fluid communication with the first exhaust conduit 22.
The plurality of exhaust conduits, as will be described in greater
detail below, are configured and arranged in cooperation with the
first exhaust conduit 22 to assure that all of the exhaust gas
passes through the plurality of catalyst devices 23-25. A second
exhaust conduit 28 is disposed in fluid communication with the
plurality of catalyst devices 23-25. The catalyst devices are
disposed in serial fluid communication between the first and second
exhaust conduits, 22 and 28. Each one of the plurality of catalyst
devices 23-25 is disposed in parallel fluid communication with each
other.
[0035] With continued reference to FIG. 1, the first exhaust
conduit 22, or exhaust manifold, is disposed in serial fluid
communication between the plurality of exhaust ports 20 and the
plurality of catalyst devices 23-25. The second exhaust conduit 28
is disposed in serial fluid communication with the plurality of
catalyst devices 23-25. The catalyst devices 23-25 are aligned
along a common plane. The common plane is generally vertical and
extends in a direction which is generally parallel with a
crankshaft of the engine 10.
[0036] Each of the catalyst devices 23-25, in a particularly
preferred embodiment of the present invention, comprises a
cylindrical housing. The housing can alternatively be generally
tubular and non-cylindrical. A catalyst material is disposed within
the generally tubular housing structure of each of the catalyst
devices 23-25. A central housing 30, or catalyst housing structure,
is provided to retain the catalyst devices 23-25 in their proper
positions relative to both the first and second exhaust conduits,
22 and 28. The path of the exhaust gas E is represented by the
arrows in FIG. 1. The exhaust gas travels from the plurality of
exhaust ports 20, through the first exhaust conduit 22, through the
catalyst devices 23-25, and through the second exhaust conduit 28.
From there, as is generally understood by those skilled in the art,
the exhaust gas is directed away from the engine 10 either through
the transom 14 and to an underwater outlet or through exhaust pipes
above and to the rear of the engine 10.
[0037] With continued reference to FIG. 1, it should be understood
that one of the advantages of a preferred embodiment of the present
invention is that the use of three catalyst devices 23-25 reduces
the overall required size of the components associated with the
exhaust system. In other words, three catalyst devices 23-25 of a
lesser diameter can be aligned as shown in FIG. 1 in a space that
requires less overall width of the engine structure than would be
needed if a single circular catalyst device was used. It should be
understood that, when the marine engine 10 is a V-type engine, two
exhaust systems are provided, one on the port side of the engine as
shown in FIG. 1 and a similarly configured exhaust system on the
starboard side of the engine.
[0038] FIG. 2 is an isometric and partially sectioned view of two
exhaust structures used in conjunction with one embodiment of the
present invention. A port exhaust structure 40 and a starboard
exhaust structure 42 are shown in FIG. 2. The port exhaust
structure 40 is sectioned to illustrate various internal
characteristics. The exhaust manifold, or first exhaust conduit 22,
directs the exhaust gas E from exhaust ports of the engine, as
described above, through a plenum region 44. The central housing
structure 30, or catalyst housing structure, has a plurality of
generally tubular cavities 43-45 formed therein. Each of the
tubular cavities is shaped to receive one of the catalyst devices
23-25 which are described above in conjunction with FIG. 1. Those
catalyst devices are not shown in FIG. 2. Each of the tubular
cavities 43-45 is sized to define a space between an inner surface,
such as surfaces 47-49, of the cavities 43-45, respectively, and an
outer surface of the generally tubular structure of the catalyst
devices 23-25. This generally annular space thus defined by the
sizes of the catalyst devices 23-25 and the generally tubular
cavities 43-45 provides an important thermally insulative function
between the catalyst devices and the catalyst housing structure 30.
As shown in FIG. 2, cooling passages 50 are provided to limit the
temperature of the first exhaust conduit 22, the catalyst housing
structure 30, and the second exhaust conduit 28. However, many
types of catalyst devices operate more efficiently and effectively
at raised temperatures. Therefore, it can become counterproductive
if the catalyst devices 23-25 receive a cooling effect as a result
of the water passing through the cooling passages 50. By providing
a space between the catalyst devices 23-25 and there respective
tubular cavities 43-45, this cooling effect is reduced. As a result
of this insulating space, the catalyst devices 23-25 operate at
higher temperatures because of the temperature of the exhaust gas E
passing through them.
[0039] FIG. 3 is a sectioned view of the port exhaust device 40.
With particular reference to catalyst device 23 in FIG. 3, it can
be seen that the outer surface 54 of the generally tubular member
56 is smaller than the inner surface 60 of the associated tubular
cavity which is described above in conjunction with FIG. 2 and
identified by reference numeral 43. This difference in size between
the outer surface 54 and the inner surface 60 defines the generally
annular space 70 surrounding the catalyst device 23. As a result,
heat is not efficiently communicated away from the catalyst device
23 toward the inner surface 60 of the tubular cavity which is
cooled by the water passages 50. The catalyst devices 23-25
therefore operate at higher temperatures than would be possible if
their tubular structures were in direct thermal contact with the
inner walls of their associated tubular cavities.
[0040] FIG. 4 is a partially sectioned view of the port exhaust
device 40. The view of FIG. 4 is a section taken along a plane that
is generally horizontal and intersects the catalyst housing
structure 30 and the three catalyst devices 23-25. This plane of
intersection is illustrated in FIG. 3 and identified by dashed line
66.
[0041] In FIG. 4, the space between the outer surface 54 of the
tubular catalyst device and the inner cylindrical surface 60 of the
tubular cavity is identified by reference numeral 70. This space is
generally annular and circular in cross-section except in the
region directly between adjacent catalyst devices 23-25. In that
region the space, identified by reference numeral 72, is larger
because of the geometry of the components and the fact that
adjacent tubular cavities, identified by reference numerals 43-45
in FIG. 2, are not isolated from each other. Also shown in FIG. 4
is a water jacket 50 surrounding the wall 76 that defines the
generally tubular cavities 43-45.
[0042] FIG. 5 is an isometric view of the port exhaust device 40
with the catalyst housing structure 30 separated to expose the
three catalyst devices 23-25. The exploded view of FIG. 5 also
shows the catalyst devices 23-25 spaced apart from the first
exhaust conduit 22 or exhaust manifold. Several characteristics of
the preferred embodiment of the present invention can be seen in
the exploded isometric view of FIG. 5. Each of the catalyst devices
23-25 has a tubular portion, which is generally cylindrical in the
embodiment shown in FIG. 5, and a rim 80 which is configured to lie
in a plane which is generally perpendicular to a central axis of
the tubular portion of the catalyst device. These rims 80 are
configured to support the associated catalyst device on an upper
surface 84 of the first exhaust conduit 22, or exhaust manifold. In
other words, the outer diameter of the rim 80 is greater than the
inner diameter 86 of an associated opening formed in the upper
surface 84 of the exhaust manifold or first exhaust conduit 22.
These relative sizes of the openings 86 and rims 80 prevent the
catalyst devices 23-25 from passing into the associated opening 86.
When the catalyst housing structure 30 is attached to the exhaust
manifold 22, the rims 80 of the catalyst devices 23-25 are captured
between opposed flange surfaces. Under the rims 80 is the surface
identified reference numeral 84 and above the rims 80 is the lower
surface of the catalyst housing structure 30. As a result of the
space 70 described above in conjunction with FIG. 4, the catalyst
devices 23-25 are generally in non-contact association with the
catalyst housing structure 30. They are supported by their
relationship of the rims 80 with the upper surface 84 of the first
exhaust conduit 22 and a lower surface of the catalyst housing
structure 30.
[0043] With continued reference to FIG. 5, a gasket 90 is disposed
on the flange surface 84 of the first exhaust conduit 22. It has a
central opening 92 formed therethrough. The central opening 92
formed through the gasket 90 is sized to allow the rims 80 to rest
on the surface 84 within the size of the opening 92. In other
words, when the catalyst housing structure 30 is attached to the
exhaust manifold 22, the rims 80 are in contact with surface 84 and
the lower surface of the catalyst housing structure 30, but the
gasket 90 is not disposed between the rims 80 and either
surface.
[0044] With reference to FIGS. 3 and 5, it can be seen that the
rims 80 provide a seal at the bottom of the spaces identified by
reference numerals 70 and 72 and described above in conjunction
with FIG. 4. This seal at the bottom of these spaces inhibits a
liquid, such as water, from flowing downward out of the spaces 70
and 72. As such, the seal cooperates with the space to form a
reservoir that captures water which may flow along the walls of the
catalyst housing structure 30 under the effect of gravity. This
water can result from condensation formed on the inner walls of the
catalyst housing structure 30. If that condensation occurs, the
seal provided by the rims 80 at the bottom portions of the catalyst
devices 23-25 inhibits the flow of that water into the exhaust
manifold 22 and, eventually, into the exhaust ports of the engine.
When the catalyst devices 23-25 reach elevated temperatures, as a
result of their direct exposure to the exhaust gas E, the increased
temperature will boil the captured water within the reservoir of
the spaces 70 and 72 and that resulting water vapor will pass
upwardly through the catalyst housing structure 30 and out of the
second exhaust conduit 28 with the exhaust gas.
[0045] FIG. 6 is a section view of the exhaust manifold 22, or
first exhaust conduit, and the catalyst housing structure 30
attached to it. FIG. 6 also shows the surface 100 of the exhaust
manifold which can be rigidly attached to a surface of the engine
through which exhaust gas is conducted through its exhaust ports.
Reference numeral 102 identifies a gasket between surface 100 of
the exhaust manifold 22 and the corresponding surface of the engine
surrounding the exhaust ports. The exhaust gas E flows from the
exhaust ports of the engine, through the exhaust manifold 22 and
through the catalyst devices 23-25 as described above in
conjunction with FIGS. 1-5. The space 70 is shown in FIG. 6
surrounding the outer surface 54 of the generally tubular portion
of the catalyst device and the inner surface 60 of the generally
tubular cavity formed within the catalyst housing structure 30.
[0046] Throughout the description of the exhaust system with
reference to FIGS. 1-6, the catalyst devices 23-25 have been
illustrated and described as being s generally cylindrical in
cross-section. However, it should be understood that this generally
cylindrical shape is not necessary in all embodiments of the
present invention. As an example, an oblong-shaped catalyst device
can also be used. FIG. 7 shows an oblong-shaped catalyst device 123
disposed within a catalyst housing structure 130. The oblong nature
of the catalyst device can be seen from its major axis 132 and the
arrow 134 which represents half of its minor axis illustrated in
the section view of the catalyst device 123 in FIG. 7. The
structure shown in FIG. 7 directs exhaust gas through four pipes
141-144 which conduct the exhaust gas to a plenum region 144 where
the exhaust gas from each pipe is free to combine with gas from
other pipes within the plenum 144 of the catalyst housing structure
130. The exhaust gas passes through the plenum 144 and then through
the catalyst device 123. After flowing through the catalyst device
123, the exhaust gas E flows into and through the second exhaust
conduit 28.
[0047] The exhaust system described above in conjunction with FIGS.
1-7 exhibits numerous advantageous characteristics which improve
the operation of a marine engine. These characteristics will be
described in greater detail below in conjunction with the specific
figures that best illustrate those characteristics.
[0048] FIG. 7 illustrates the oblong catalyst device 123 and FIG. 1
shows the relative positions of the exhaust ports 20 on the marine
engine 10. It should be understood that the generally cylindrical
exhaust devices 23-25 could be replaced within the catalyst housing
structure 30 by an appropriately shaped oblong catalyst device such
as that which is identified by reference numeral 123 in FIG. 7.
[0049] With reference to FIGS. 1 and 7, one embodiment of the
present invention comprises a plurality of exhaust ports 20, a
first exhaust conduit, 22 or 122, an oblong catalyst device 123 and
a second exhaust conduit, 28 or 128. The first exhaust conduit 122
is disposed in fluid communication with the plurality of exhaust
ports by the exhaust pipes 141-144. The oblong catalyst device 123
is disposed in fluid communication with the first exhaust conduit,
22 or 122. The oblong catalyst 123 has a major axis 132, a minor
axis, half of which is represented by arrow 134, and a central axis
which extends through the catalyst device in a direction generally
parallel to the arrows representing the flow of exhaust gas E. The
oblong catalyst device is configured to conduct the exhaust gas E
in a direction generally perpendicular to the major and minor axes,
132 and 134, and generally parallel to the central axis. The second
exhaust conduit, 28 or 128, is disposed in fluid communication with
the oblong catalyst device 123. The oblong catalyst device is
disposed in serial fluid communication between the first and second
exhaust conduits, 122 and 128.
[0050] The configuration of a preferred embodiment of the present
invention, described above in conjunction with FIGS. 1-7, promotes
a generally uniform flow of exhaust gas through the catalyst
module, whether the catalyst module comprises a plurality of
catalyst devices 23-25 or whether it comprises a single larger
catalyst device 123. With reference to FIGS. 2 and 6, the exhaust
gas E flowing into the exhaust manifold 22, or first exhaust
conduit, flows from regions of relatively smaller cross-sectional
area (e.g. the exhaust ports of the engine) to a plenum area 44
having a greater cross-sectional area. As a result of this increase
in cross-sectional area along the path of the exhaust gas E, the
velocity of the exhaust gas decreases. This allows the exhaust to
more uniformly seek areas of lower pressure along the inlet
surfaces of the catalyst devices 23-25. In other words, without the
plenum area 44, the exhaust gas stream would be more subject to the
influences of gas stream velocity and momentum that could urge the
exhaust to flow through limited portions of the inlet area of the
catalyst devices. However, when a plenum 44 is provided, the
velocity of the gas stream slows and allows the exhaust to more
uniformly seek lower pressure areas along the inlet surfaces of the
catalyst devices. Rather than directing the exhaust gas stream with
a restrictive conduit, the expanded area 44 of the plenum decreases
the velocity of the flow and encourages a more uniform distribution
of the exhaust gas through the plurality of exhaust devices or,
alternatively, through all of the areas of the inlet of a single
catalyst device.
[0051] With reference to FIGS. 1 and 3, a non-catalytic porous
member 150 is disposed within the second exhaust conduit 128. This
non-catalyst porous member can be made of the same material used to
begin the manufacturing process associated with the catalyst
devices 23-25. That manufacturing process is described in U.S. Pat.
Nos. 6,368,726 and 6,639,193. U.S. Pat. Nos. 6,660,235 and
6,740,178 also describe the manufacturing process associated with
creating a catalyst device. The internal portions of the catalyst
devices described in those patents comprise a support structure
which is porous. The support. structure is also provided with a
catalytic material to manufacture a catalyst device. The
non-catalytic porous member 150 comprises the internal support
structure, but without the catalytic material being included. Its
purpose is not to serve as a catalyst device. Its purpose is to
serve as a structure which inhibits the flow of liquid water in a
reverse direction through the second exhaust conduit 28. Exhaust
gas freely passes through the porous non-catalytic member as it
flows away from the engine 10. As a result, the non-catalytic
porous member is heated to approximately the temperature of the
exhaust gas stream. If water attempts to migrate in a reverse
direction through the non-catalytic porous member 150, it will be
rapidly evaporated and the resulting vapor will be carried away
from the engine 10 by the exhaust stream. This embodiment of the
present invention provides an exhaust conduit 128 disposed in
serial fluid communication downstream from a plurality of exhaust
ports 20 as described above. The non-catalytic porous member can
comprise a metallic mesh material and it can be configured to
direct the exhaust gas through the metallic mesh material. In a
preferred embodiment, the non-catalyst porous member comprises a
metallic catalytic substrate, but without a catalytic coating.
[0052] The embodiment of the present invention described above in
conjunction with FIGS. 1-6 comprises a catalyst device (e.g.
devices 23-25) that comprises a first catalyst material disposed
within a first housing structure, such as the tubular or
cylindrical structure illustrated in FIG. 5. The tubular portion of
the catalyst devices has a central axis. The rim portion 80 extends
from an end of the generally tubular portion and is disposed in a
plane which is generally perpendicular to the central axis of the
tubular portion. A gasket 90 is disposable between the exhaust
manifold 22 and the catalyst housing structure 30. The gasket 90 is
disposed between the two flange surfaces which include the upper
surface 84 of the exhaust manifold 22 and the lower surface of the
catalyst housing structure 30. The gasket has an opening 92 which
is formed through its thickness. The opening 92 is configured to
receive the rim portion 80 of a catalyst device. The size of the
opening 92 is selected to allow the rim portions 80 to be captured
between the upper surface 84 of the exhaust manifold 22 and the
lower surface of the catalyst housing 30 without the gasket 90
being compressed between the rim portion 80 and either of the two
flange surfaces.
[0053] As described above in conjunction with FIGS. 3, 4 and 6, the
outer surface 54 of each tubular catalyst device 23-25 is shaped to
be received within an associated tubular cavity 43-45 with a space
70 therebetween. The space 70 is a generally annular space defined
by the difference in size between the outer surface 54 of the
catalyst devices 23-25 and the inner surface 60 of the associated
tubular cavity. This space 70 provides an effective thermal
insulation between the catalyst devices 23-25 and the catalyst
housing structure 30. The presence of the rim 80 at the bottom
portion of each catalyst device 23-25 provides a seal which
prevents liquid from flowing downward and out of the space 70 if
liquid is trapped therein. As a result, a reservoir is defined
which holds the liquid until the temperature becomes sufficiently
high to boil the liquid and allow the water vapor to escape with
the gas stream.
[0054] With reference to FIG. 5, a concentricity spacer 160 is
provided for each of the catalyst devices 23-25. The purpose of the
concentricity spacer is to maintain the outer cylindrical surface
of the catalyst devices in a concentric relationship with the inner
cylindrical surface of the associated tubular cavity 43-45. The
concentricity spacer 160, in a preferred embodiment of the present
invention, comprises a relatively thin sheet of material that is
embossed with raised portions which maintain the concentricity of
the catalyst device and its associated tubular cavity while
allowing fluid to flow in a vertical direction past the
concentricity spacer.
[0055] With reference to FIGS. 3 and 4, two oxygen sensors are
illustrated. An upstream oxygen sensor 170 is disposed in fluid
communication with the exhaust gas passing through the exhaust
manifold 22. A downstream oxygen sensor 175 is disposed in the
upper portion of the catalyst housing structure 30.
[0056] As shown in FIG. 4, the upstream oxygen sensor 170 is
disposed within the overall exhaust structure and, more
specifically, within the exhaust manifold 22. It is therefore
disposed downstream from the plurality of exhaust ports 20 (shown
in FIG. 1) and upstream from the catalyst devices 23-25. The oxygen
sensor 170 is configured to remain at or below the temperature of
the exhaust gas E when the exhaust gas is flowing from the
plurality of exhaust ports 20 as shown in FIG. 1. In other words,
the oxygen sensor 170 located upstream from the catalyst devices
23-25 is unheated other than the effect it experiences from the hot
exhaust gas flowing over it. The unheated nature of the upstream
oxygen sensor 170 provides a significant advantage because it is
less susceptible to damage in the event that liquid, such as water
condensate, flows in a reverse direction from the second exhaust
conduit 28 toward the plurality of exhaust ports of the engine 10.
If the upstream oxygen sensor 170 is heated, as most oxygen sensors
now are, it could be severely damaged if water flows in contact
with it. The use of an unheated oxygen sensor 170 therefore
provides a significant benefit in an exhaust system of a marine
engine.
[0057] FIG. 3 illustrates an advantage provided by the system
described herein in conjunction with a reverse flow of liquid, as
represented by arrows W, from the second exhaust conduit 28 toward
the catalyst devices 23-25. The downstream oxygen sensor 175 is
disposed within the catalyst housing structure 30 and in fluid
communication with the plurality of exhaust ports 20 described
above in conjunction with FIG. 1. It is also disposed in fluid
communication with the second exhaust conduit 28. The second
exhaust conduit 28 is connected to a first portion of the catalyst
housing structure 30 which, as illustrated in FIG. 3, is at the
upper right portion of this device. The oxygen sensor 175 is
connected to a second portion of the catalyst housing structure 30
which is located at the upper left portion as shown in FIG. 3. In a
preferred embodiment of the present invention, the first and second
portions are disposed at opposite sides of the catalyst housing
structure 30 as shown.
[0058] With continued reference to FIG. 3, the first exhaust
conduit 22, the catalyst housing structure 30 and the catalyst
device 23-25 are configured and arranged to cooperatively define a
reversion liquid trajectory path W for water that flows in a
direction from the second exhaust conduit 28 toward the first
exhaust conduit 22. This reversion liquid trajectory path is
governed by the positions of the second exhaust conduit 28 and the
catalyst devices 23-25 in conjunction with the resulting inertia of
the water droplets as they flow under the effect of differential
pressure that can result from the opening of exhaust valves of the
engine.
[0059] The causes for water reversion are well known to those
skilled in the art of marine propulsion systems. As water droplets
are caused to flow in a reverse direction, as indicated by arrows
W, the trajectory of those water droplets is governed by the
magnitude of the differential pressure between the second exhaust
conduit 28 and the first exhaust conduit 22 in conjunction with the
size of the various droplets, the shape of the internal cavity of
the catalyst housing structure 30, and the positions of the upper
portions of the catalyst devices 23-25. The location of the
downstream oxygen sensor 175 is selected, in a preferred embodiment
of the present invention, to be away from this reversion liquid
trajectory path illustrated by arrows W in FIG. 3. As such, the
water droplets are less likely to strike the downstream oxygen
sensor 175. This advantageous location of the downstream oxygen
sensor 175 therefore avoids damage that would otherwise occur to it
if the hot sensor 175 is struck by water droplets flowing in a
reverse direction from the second exhaust conduit 28 toward the
catalyst devices 23-25.
[0060] Although the present invention has been described in
particular detail and illustrated to show various embodiments, it
should be understood that alternative embodiments are also within
its scope.
* * * * *