U.S. patent application number 12/644123 was filed with the patent office on 2011-06-23 for exhaust stack with baffles.
This patent application is currently assigned to Caterpillar Inc.. Invention is credited to Paul F. Olsen.
Application Number | 20110151760 12/644123 |
Document ID | / |
Family ID | 44151747 |
Filed Date | 2011-06-23 |
United States Patent
Application |
20110151760 |
Kind Code |
A1 |
Olsen; Paul F. |
June 23, 2011 |
EXHAUST STACK WITH BAFFLES
Abstract
An exhaust stack is disclosed for protecting exhaust system
components from liquid entering an exhaust stack discharge port.
The exhaust stack includes a first section defining a first flow
passage extending along a first longitudinal axis and a second
section having an open end and defining a second flow passage
extending along a second longitudinal axis. The exhaust stack
further includes a liquid drain disposed in the first section and
one or more baffles disposed in the second flow passage, wherein
the one or more baffles are configured to block line-of-sight
between the open second end and any inner surface below the liquid
drain
Inventors: |
Olsen; Paul F.;
(Chillicothe, IL) |
Assignee: |
Caterpillar Inc.
Peoria
IL
|
Family ID: |
44151747 |
Appl. No.: |
12/644123 |
Filed: |
December 22, 2009 |
Current U.S.
Class: |
454/41 ;
454/1 |
Current CPC
Class: |
F01N 13/00 20130101;
F23J 2900/13005 20130101; F23L 17/14 20130101; F01N 3/005
20130101 |
Class at
Publication: |
454/41 ;
454/1 |
International
Class: |
F01N 13/08 20100101
F01N013/08; F23J 11/00 20060101 F23J011/00 |
Claims
1. An exhaust stack, comprising: a first section defining a first
flow passage extending along a first longitudinal axis; a second
section defining a second flow passage extending along a second
longitudinal axis, the second flow passage in fluid communication
with the first flow passage, the second longitudinal axis extending
at an angle to the first longitudinal axis, the second section
having an open end; a liquid drain disposed in the first section;
and one or more baffles disposed in the second flow passage,
wherein the one or more baffles are configured to block
line-of-sight between the open end and any inner surface below the
liquid drain.
2. The exhaust stack of claim 1 wherein the liquid drain extends
around a circumference of an inner surface of the first
section.
3. The exhaust stack of claim 2 wherein the liquid drain includes
an aperture configured to direct liquid from the liquid drain to an
exterior surface of the first section.
4. The exhaust stack of claim 1 wherein the one or more baffles do
not extend over the first flow passage.
5. The exhaust stack of claim 1 wherein the open end terminates in
a plane substantially parallel with the first longitudinal
axis.
6. The exhaust stack of claim 1 wherein the one or more of baffles
include a plurality of baffles that are substantially parallel to
each other.
7. The exhaust stack of claim 1 wherein the one or more baffles
extend in a direction substantially parallel to the second
longitudinal axis.
8. The exhaust stack of claim 1 wherein the one or more baffles are
configured such that liquid falling by gravity from the one or more
baffles will contact an inner surface of the exhaust stack between
the liquid drain and the one or more baffles.
9. The exhaust stack of claim 1 wherein the one or more baffles
include a body portion and a lip extending from the body portion,
the lip configured to route liquid to an inner surface of the
exhaust stack between the liquid drain and the one or more
baffles.
10. A power system, comprising: an engine; an exhaust manifold
configured to receive exhaust from the engine; an exhaust stack
configured to receive exhaust from the exhaust manifold, the
exhaust stack comprising: a first section defining a first flow
passage extending along a first longitudinal axis; a second section
defining a second flow passage extending along a second
longitudinal axis, the second flow passage in fluid communication
with the first flow passage, the second longitudinal axis extending
at an angle to the first longitudinal axis, the second section
having an open end; a liquid drain disposed in the first section;
one or more baffles disposed in the second flow passage, wherein
the one or more baffles are configured to block line-of-sight
between the open end and any inner surface below the liquid
drain.
11. The power system of claim 10 wherein the liquid drain extends
around a circumference of an inner surface of the first
section.
12. The power system of claim 11 wherein the liquid drain includes
an aperture configured to direct liquid from the liquid drain to an
exterior surface of the first section.
13. The power system of claim 10 wherein the one or more baffles do
not extend over the first flow passage.
14. The power system of claim 10 wherein the open end terminates in
a plane substantially parallel with the first longitudinal
axis.
15. The power system of claim 10 wherein the one or more of baffles
include a plurality of baffles that are substantially parallel to
each other.
16. The power system of claim 10 wherein the one or more baffles
extend in a direction substantially parallel to the second
longitudinal axis.
17. The power system of claim 10 wherein the one or more baffles
are configured such that liquid falling by gravity from the one or
more baffles will contact an inner surface of the exhaust stack
between the liquid drain and the one or more baffles.
18. The power system of claim 10 wherein the one or more baffles
include a body portion and a fin extending from the body portion,
the fin configured to route liquid to an inner surface between the
liquid drain and the one or more baffles.
19. A method of protecting exhaust system components from liquid
entering an exhaust stack discharge port, comprising: providing a
liquid drain along an exhaust flow path in the exhaust stack;
blocking line-of sight between the exhaust stack discharge port and
any inner surface of the exhaust system below the liquid drain;
positioning one or more baffles in the exhaust stack such that
liquid falling by gravity from the one or more baffles will contact
an inner surface of the exhaust stack between the liquid drain and
the one or more baffles.
20. The method of claim 19 further comprising collecting liquid
that flows down the inner surface of the exhaust stack and
transporting the collected liquid to an exterior of the exhaust
stack.
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to an exhaust
system and, more particularly, to an exhaust system having one or
more baffles disposed near the discharge end.
BACKGROUND
[0002] Internal combustion engines, including diesel engines,
gasoline engines, natural gas engines, turbine engines, and other
engines known in the art, are used to drive many types of power
systems. Exhaust from the internal combustion engines is typically
discharged into the atmosphere. A power system may include an
exhaust stack that extends vertically from the engine or from an
enclosure of the engine in order to discharge the exhaust. As such,
it is possible for precipitation to enter the exhaust stack when
the engine is non-operational (i.e., when the exhaust stack is not
being pressurized by a flow of exhaust). When the engine is
operational, precipitation can also enter the exhaust stack where
the exhaust flow is weakest.
[0003] Moisture in the exhaust system can damage various exhaust
system components, such as after-treatment devices. For example,
diesel particular filters (DPFs) often utilize a ceramic wall-flow
substrate. When the engine is non-operational in cold environments,
water in the exhaust system may freeze. If in contact with the
ceramic substrate, the freezing and expansion of the water may
crack the substrate.
[0004] To avoid problems with moisture, such as precipitation,
entering the exhaust system via a vertically extending stack, some
stacks include protective devices. For example, U.S. Pat. No.
2,630,748 (hereinafter the '748 patent), by Brockelsby, discloses
an exhaust rain protector. The '748 patent discloses using an
adapter that mounts onto a vertically extending exhaust pipe. The
adapter includes a pair of angled baffles that divert any rain
water entering the exhaust discharge end out a pair of spouts and
create maze-like flow path for the exhaust that prevents water from
entering the exhaust system past the baffles.
[0005] While the device disclosed in the '748 patent may prevent
rainwater from entering the exhaust system, it requires fitting an
offset, bulky adapter onto the end of the exhaust pipe that
increase space and height of the exhaust stack. Furthermore, the
device is ill-suited for exhaust stacks already having an angled
discharge end. Still further, the maze-like flow path may result in
an undesirable increase in exhaust back pressure.
[0006] The present disclosure is directed to overcoming one or more
of the shortcomings in the existing technology.
SUMMARY OF THE DISCLOSURE
[0007] In accordance with one aspect, the present disclosure is
directed an exhaust stack having a first section defining a first
flow passage extending along a first longitudinal axis and a second
section having an open end and defining a second flow passage
extending along a second longitudinal axis. The exhaust stack
further includes a liquid drain disposed in the first section and
one or more baffles disposed in the second flow passage, wherein
the one or more baffles are configured to block line-of-sight
between the open second end and any inner surface below the liquid
drain.
[0008] According to another aspect, the present disclosure is
directed toward a method of protecting exhaust system components
from liquid entering an exhaust stack discharge port. The method
includes providing a liquid drain along an exhaust flow path in the
exhaust stack, blocking line-of sight between the exhaust stack
discharge port and any inner surface of the exhaust system below
the liquid drain, and positioning one or more baffles in the
exhaust stack such that liquid falling by gravity from the one or
more baffles will contact an inner surface of the exhaust stack
between the liquid drain and the one or more baffles.
[0009] Other features and aspects of this disclosure will be
apparent from the following description and the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In the accompanying drawings, which are incorporated in and
constitute a part of this specification, exemplary embodiments of
the disclosure are illustrated, which, together with the written
description, serve to explain the principles of the disclosed
system:
[0011] FIG. 1 is a side cross section illustration of an exemplary
power system with a first embodiment of an exhaust stack;
[0012] FIG. 2 is a front view of the exhaust stack of FIG. 1;
[0013] FIG. 3 is a side cross section illustration of an exemplary
power system with a second embodiment of an exhaust stack; and
[0014] FIG. 4 is a side cross section illustration of another
embodiment of a liquid drain of the exhaust stack of FIG. 3.
DETAILED DESCRIPTION
[0015] Referring to FIG. 1, an exemplary power system 10 is
disclosed. The power system 10 may include an engine 12, an exhaust
system 14, and a housing 16. The engine 12 may include features not
shown, such as fuel systems, air systems, cooling systems,
peripheries, drivetrain components, turbochargers, etc. The engine
12 may be any type of engine (internal combustion, turbine, gas,
diesel, gaseous fuel, natural gas, propane, etc.), may be of any
size, with any number of cylinders, and in any configuration ("V,"
in-line, radial, etc.). The engine 12 may be used to power any
machine or other device, including locomotive applications,
on-highway trucks or vehicles, off-highway trucks or machines,
earth moving equipment, generators, aerospace applications, marine
applications, pumps, stationary equipment, or other engine powered
applications.
[0016] The housing 16 may be any structure that encloses or
partially encloses the engine 12 and exhaust system 14. For
example, the housing 16 may be a vehicle body or hood.
[0017] The exhaust system 14 may include an exhaust manifold 18,
one or more exhaust aftertreatment devices 20 designed to reduce
undesirable emissions from the exhaust of the engine 12, and an
exhaust stack 22. The exhaust aftertreatment devices 20 may include
a variety of emissions treatment technology, including, but not
limited to, regeneration devices, heat sources, oxidation
catalysts, diesel oxidation catalysts (DOCs), diesel particulate
filters (DPFs), selective catalytic reduction catalysts (SCRs),
lean NOx traps (LNTs), mufflers, or other devices needed to treat
the exiting the engine 12.
[0018] In the depicted embodiment, the exhaust aftertreatment
devices 20 include a diesel particulate filter (DPF) 24. The DPF 24
may include a DPF substrate 26 at least partially disposed within a
DPF housing 28. The DPF substrate 26 may be configured in a variety
of ways. Any structure capable of removing particulate matter from
the exhaust of the engine 12 may be used. For example, the DPF
substrate may a wall-flow ceramic structure having a honey-comb
cross-section constructed of cordierite, silicon carbide, or other
material to remove the particulate matter.
[0019] The exhaust stack 22 may be configured in a variety of ways.
Any structure capable of routing exhaust exiting the power system
10 in a desired direction may be used. For example, the
cross-sectional shape of the exhaust stack 22 may be circular or
may be some other geometric shape. The exhaust stack 22 may extend
substantially vertically upward or may extend at an angle to
vertical. Referring to FIG. 1, in the first depicted embodiment,
the exhaust stack 22 includes a first section 30 defining a first
flow passage 31 and a second section 32 defining a second flow
passage 33. The first section 30 is configured as a substantially
cylindrical tube extending along a first longitudinal axis 34 and
having a first inner surface 36. The first section 30 may have a
first end 38 configured to receive exhaust from the engine 12 and a
second end 40 configured to fluidly couple to the second section
32.
[0020] The first section 30 may include a liquid drain 42. The
liquid drain 42 may be configured in a variety of ways. Any
structure capable of collecting or redirecting liquid (such as
water) that flows down the first inner surface 36 of the first
section 30 may be used. In the depicted embodiment, the liquid
drain 42 is configured as an annular trough having a bottom wall 44
disposed between a sidewall 46 and the first inner surface 36. One
or more apertures 48 may be formed in the first inner surface 36
adjacent the bottom wall 44. The one or more apertures 48 being
configured to transport liquid from the trough (and interior of the
stack) to the exterior of the first section 30.
[0021] In the depicted embodiment, the second section 32 is
configured as a substantially cylindrical tube extending along a
second longitudinal axis 49 and having a second inner surface 50.
The second longitudinal axis 49 may be disposed at an angle .theta.
relative to the first longitudinal axis 34. The second section 32
may have a first end 52 fluidly coupled to the second end 40 of the
first section 30. The second section 32 may also have an open
second end 54 that terminates to form an exhaust stack discharge
port. The open second end 54 may terminate in a plane that is
substantially parallel with the first longitudinal axis 34.
[0022] The second section 32 may include one or more baffles 56
disposed in the second flow passage 33. The number of baffles 56
and the shape, size, and orientation of the baffles may vary. Any
structure(s) capable of protecting the exhaust aftertreatment
device(s) 20 from water entering the discharge port of the stack
may be used. In the depicted embodiment, the four baffles are
arranged in the second section 32, though more or less baffles may
be used. Each baffle 56 has a generally elongated body having a
first end 58 and a second end 60.
[0023] The one or more baffles 56 may be arranged generally
parallel to the second longitudinal axis 49 (i.e. at an angle
.theta. to the first longitudinal axis 34) and generally parallel
with each other. The second end 60 of each baffle may be generally
located proximate the open second end 54 of the second section
32.
[0024] Referring to FIG. 2, each the one or more baffles 56 may
extend horizontally across the open second end 54 such that exhaust
that exits the exhaust stack 22 flows between two adjacent baffles
56 or between a baffle 56 and the second inner surface 50 of the
second section 32. Each of the one or more baffles 56 may have one
or more side surfaces 62. The one or more side surfaces 62 may
follow the contour of the second inner surface 62. The one or more
baffles 56 may be fixably attached to the second inner surface 50
by any suitable means, such as fasteners or welding. For example,
one or more side surfaces 62 of a baffle 56 may be welded to the
inner surface 50 of the section second 32.
[0025] Referring to FIG. 1, the first end 58 of each baffle 56 may
be if located a distance D from the edge or intersection between
the first section 30 and the second section 32. Thus, the first end
58 does not extend into or over the first flow passage 31 and, as
viewed in FIG. 1, is over the second inner surface 50.
[0026] Referring to FIG. 3, a second embodiment of an exemplary
exhaust stack is disclosed. The exhaust stack 122 illustrated in
FIG. 3, is similar to the exhaust stack 22 of FIG. 1, with the
exception of a baffle modification. Thus, the power system 110 of
FIG. 3 may include an engine 112, an exhaust system 114, and a
housing 116. The exhaust system 114 may include an exhaust manifold
118, one or more exhaust aftertreatment devices 120 and the exhaust
stack 122.
[0027] The exhaust aftertreatment devices 120 may include for
example, a diesel particulate filter (DPF) 124 that includes a DPF
substrate 126 at least partially disposed within a DPF housing
128.
[0028] The exhaust stack 122 may be configured in a variety of
ways. Any structure capable of routing exhaust exiting the power
system 110 in a desired direction may be used. The exhaust stack
122 may extend substantially vertically upward or may extend at an
angle to vertical. In the depicted embodiment, the exhaust stack
122 includes a first section 130 defining a first flow passage 131
and a second section 132 defining a second flow passage 133. The
first section 130 is configured as a substantially cylindrical tube
extending along a first longitudinal axis 134 and having a first
inner surface 136. The first section 130 may have a first end 38
configured to receive exhaust from the engine 112 and a second end
140 configured to fluidly couple to the second section 132.
[0029] The first section 130 may include a liquid drain 142. The
liquid drain 42 may be configured in a variety of ways. Any
structure capable of diverting and/or catching liquid (such as
water) that flows down the first inner surface 136 may be used. In
the depicted embodiment, the liquid drain 142 is configured as an
annular trough having a bottom wall 144 disposed between a sidewall
146 and the first inner surface 136. One or more apertures 148 may
be formed in the first inner surface 136 adjacent the bottom wall
144. The one or more apertures 148 being configured to allow liquid
to flow from the trough (and interior of the stack) to the exterior
of the first section 130. Thus, the liquid drain 42 catches and
diverts the liquid so that the liquid does not continue to flow
down the interior of the pipe.
[0030] Referring to FIG. 4, in another embodiment of the liquid
drain, the first section 230 may include an upper portion 232 and a
lower portion 234. The lower portion 234 includes an inward flared
inlet or venturi inlet 236 that at least partially is received
within the upper portion 232. One or more apertures 238 may be
formed between the upper portion 232 and the lower portion 234 to
form a liquid drain 242. Thus, liquid that flows down the inner
surface of the upper portion 232 will not enter the flared inlet
236 of the lower portion 234 and will be diverted to the exterior
of the stack. In another embodiment, one or more baffles (not
shown) may be positioned proximate the inlet 236 to further divert
any liquid away from entering the inlet 236.
[0031] In the depicted embodiment, the second section 132 is
configured as a substantially cylindrical tube extending along a
second longitudinal axis 138 and having a second inner surface 150.
The second longitudinal axis 138 may be disposed at an angle
.theta. relative to the first longitudinal axis 134. The second
section 132 may have a first end 152 fluidly coupled to the second
end 140 of the first section 130. The second section 132 may also
have an open second end 154 that terminates to form an exhaust
discharge port. The open second end 154 may terminate in a plane
that is substantially parallel with the first longitudinal axis
134.
[0032] The second section 132 may include one or more baffles 156
disposed in the second flow passage 133. The number of baffles 156
and the shape, size, and orientation of the baffles may vary. Any
structure(s) capable of protecting the exhaust aftertreatment
device(s) 120 from water entering the discharge port of the stack
may be used. In the depicted embodiment, the two baffles are
arranged in the second section 132, though more or less baffles may
be used. Each baffle 156 has a generally elongated body having a
first end 158 and a second end 160. The one or more baffles 156 may
be arranged generally parallel with each other. In the depicted
embodiment, the two baffles 156 are not parallel to the second
longitudinal axis 138. In other embodiments, however, the baffles
156 may be parallel with the second longitudinal axis 138.
[0033] Each of the baffles 156 may include a lip 166 extending
outward at an angle from the second end 160. In the depicted
embodiment, the lip 166 extends in a generally perpendicular
direction from the baffle 156. The lip 166 may be configured to
collect and channel any liquid on the baffle 156 to the second
inner surface 150.
[0034] Unlike the embodiment of FIG. 1, the second end 160 of each
baffle 156 may extend into or over the first flow passage 131.
INDUSTRIAL APPLICABILITY
[0035] The disclosed exhaust stack may be applicable to any power
system 10 such as for example an engine, a furnace or any other
power source know in the art where precipitation may enter the
exhaust stack and cause damage to the exhaust system components,
including exhaust after treatment devices. The disclosed exhaust
stack may prevent water, which may enter the discharge port of the
exhaust stack, from making contact with an exhaust aftertreatment
device in the exhaust system, such as a DPF substrate. As a result,
the concern of water, in contact with the DPF substrate, freezing
and cracking the substrate is eliminated. The operation of exhaust
system 14 will now be explained.
[0036] Atmospheric air may be drawn into the engine 12, mixed with
fuel, and then be combusted to produce mechanical work. Exhaust
from the combustion of the air-fuel mixture may contain gaseous
compounds and solid particulate matter. The exhaust may be directed
from engine 12 to the exhaust system 14, and then directed via the
exhaust stack 22 to an exterior of power system 10.
[0037] Since, the open second end 54 of the exhaust stack 22 may be
directed upward and open to atmosphere, precipitation,
sprayed/splashed water or other liquid may enter the exhaust stack
22 and flow downward toward one or more exhaust aftertreatment
devices 20.
[0038] The baffles 56, however, may be configured to prevent or
reduce the amount of liquid that may reach the exhaust
aftertreatment device(s) 20. In particular, the one or more baffles
56 may block line-of-sight between the open second end 54 and any
inner surface below the liquid drain 42. Thus, the trajectory of
any liquid that enters the open second end 54 and does not contact
any of the one or more baffles 56 will direct the liquid onto the
first inner surface 36 or second inner surface 50 above the liquid
drain 42. Therefore, the liquid will flow down the first inner
surface 36, be collected by the liquid drain 42, and redirected to
the exterior of the exhaust stack 22 via the one or more apertures
48 before reaching the DPF substrate 26, for example.
[0039] In addition, in the exemplary embodiment of FIG. 1, the
first end 58 of each of the one or more baffles 56 does not extend
into or over the first flow passage 31. Thus, any liquid that
contacts the one or more baffles 56 will flow off of the first end
58 of each baffle 56 and fall, by gravity, onto the second inner
surface 50. Once on the second inner surface 50, the liquid will
flow down the first inner surface 36, be collected by the liquid
drain 42, and redirected to the exterior of the exhaust stack
22.
[0040] In the exemplary embodiment of FIG. 3, any liquid that
contacts the one or more baffles 156, will flow to the lip 166 and
be channeled to the second inner surface 150. Once on the second
inner surface 50, the liquid will flow down the first inner surface
36, be collected by the liquid drain 42, and redirected to the
exterior of the exhaust stack 22.
[0041] Thus, the exhaust stack 22 provides protection to exhaust
system components from liquid entering the stack. Furthermore,
since the one or more baffles may be angled in =lien with the flow
of exhaust exiting the stack, the baffles providing minimal
increase in exhaust back pressure.
[0042] It will be apparent to those skilled in the art that various
modifications and variations can be made to the disclosed dosing
system. Other embodiments will be apparent to those skilled in the
art from consideration of the specification and practice of the
disclosed method and apparatus. It is intended that the
specification and examples be considered as exemplary only, with a
true scope being indicated by the following claims and their
equivalents.
* * * * *