U.S. patent application number 10/439088 was filed with the patent office on 2004-11-18 for heat exchanger with removable core.
Invention is credited to Beldam, Richard Paul, Dilley, Roland, Smith, Willi J..
Application Number | 20040226694 10/439088 |
Document ID | / |
Family ID | 33417718 |
Filed Date | 2004-11-18 |
United States Patent
Application |
20040226694 |
Kind Code |
A1 |
Dilley, Roland ; et
al. |
November 18, 2004 |
Heat exchanger with removable core
Abstract
There is provided a heat exchanger, such as an exhaust gas
cooler, that has a removable core at least partially disposed in a
shell. Tubes extending through the shell fluidly connect tanks at
both ends of the shell so that thermal energy can be transferred
between a first fluid in the shell and a second fluid in the tubes.
At least one of the tanks is defined partially by a tube sheet, and
the tank is structured to be moved axially through the shell in a
direction toward the opposite tank and removed from the shell with
the tubes. A sealing member is disposed between the movable tank
and the shell to prevent fluid from flowing therebetween.
Inventors: |
Dilley, Roland; (Lomita,
CA) ; Beldam, Richard Paul; (Torrance, CA) ;
Smith, Willi J.; (Torrance, CA) |
Correspondence
Address: |
Ephraim Starr, Division General Counsel
Honeywell International Inc.
Suite #200
23326 Hawthorne Boulevard
Torrance
CA
90505
US
|
Family ID: |
33417718 |
Appl. No.: |
10/439088 |
Filed: |
May 14, 2003 |
Current U.S.
Class: |
165/82 ;
165/159 |
Current CPC
Class: |
F28F 2280/02 20130101;
F28D 21/0003 20130101; F28F 9/0239 20130101; F28D 7/1607
20130101 |
Class at
Publication: |
165/082 ;
165/159 |
International
Class: |
F28F 007/00; F28D
007/00; F28F 009/22 |
Claims
That which is claimed:
1. A heat exchanger with a removable core, the heat exchanger
comprising: a tubular shell extending between first and second ends
and defining an interior space for receiving a first fluid; a core
comprising: a first tank at the first end of the shell; a second
tank at the second end of the shell, the second tank and shell
defining a junction therebetween; and a plurality of
fluid-conducting members extending between the first and second
tanks and fluidly connecting the first and second tanks such that a
second fluid disposed in the tanks is fluidly disconnected from the
interior space of the shell; and a sealing member disposed between
the shell and the core such that the core is free to adjust axially
relative to the shell and the sealing member prevents fluid from
flowing through the junction between the core and the shell,
wherein the core is structured to be axially moved through the
shell in a direction from the second end toward the first end of
the shell and removed therefrom as a unit.
2. A heat exchanger according to claim 1 wherein the shell defines
inlet and outlet ports for circulating the first fluid.
3. A heat exchanger according to claim 1 wherein the second tank
comprises a second tank member fixedly attached to a tube sheet,
the tube sheet defining a plurality of holes corresponding to the
tubes.
4. A heat exchanger according to claim 3 wherein the second tank
member is attached to the second tube sheet by at least one of the
group that includes a weld joint, a braze joint, and a solder
joint.
5. A heat exchanger according to claim 1 wherein the sealing member
comprises at least one elastic o-ring.
6. A heat exchanger according to claim 1 wherein at least one of an
inner surface of the shell and an outer surface of the second tank
defines at least one groove for receiving the sealing member.
7. A heat exchanger according to claim 1 wherein the sealing member
fluidly disconnects the interior space of the shell from an
exterior of the shell and the sealing member is fluidly
disconnected from the second fluid in the second tank.
8. A heat exchanger according to claim 7 wherein the sealing member
is adjacent a portion of the second tank that is fluidly
disconnected from the second fluid.
9. A heat exchanger according to claim 1 wherein the first tank is
removably connected to the shell.
10. A heat exchanger according to claim 1 further comprising a
resilient member disposed between the shell and the first tank such
that the first tank is flexibly connected to the shell.
11. A heat exchanger according to claim 1 wherein the shell defines
a tapered inner surface having an inner surface portion proximate
the second end with a diameter that corresponds in size to an outer
surface of the second tank such that the sealing member forms a
fluid seal therebetween.
12. An exhaust gas cooler with a removable core, the exhaust gas
cooler comprising: a tubular shell extending between first and
second ends, the shell defining an interior space and at least one
port for receiving a coolant; a first tank at the first end of the
shell, the first tank being defined at least partially by a first
tube sheet, the first tank defining at least one port for receiving
a hot exhaust gas; a second tank at the second end of the shell,
the second tank being defined at least partially by a second tube
sheet and a second tank member fixedly attached to the second tube
sheet, the second tank and shell defining an annular junction
therebetween; a plurality of tubes extending between the first and
second tube sheets and fluidly connecting the first and second
tanks such that the exhaust gas flows therebetween; a sealing
member disposed between the shell and the second tank such that the
second tank is configured to adjust axially relative to the shell
and the sealing member prevents the coolant fluid from flowing
through the junction between the second tank and the shell, wherein
the second tank is structured to be axially moved through the shell
in a direction from the second end toward the first end of the
shell and removed therefrom.
13. An exhaust gas cooler according to claim 12 wherein the second
tank member is attached to the second tube sheet by at least one of
the group that includes a weld joint, a braze joint, a solder
joint, a bolt, a clamp, an interference fit, and a mechanical
interlock.
14. An exhaust gas cooler according to claim 12 wherein the sealing
member comprises at least one elastic o-ring.
15. An exhaust gas cooler according to claim 12 wherein at least
one of an inner surface of the shell and an outer surface of the
second tank defines at least one groove for receiving the sealing
member.
16. An exhaust gas cooler according to claim 12 wherein the sealing
member fluidly disconnects the interior space in the shell from an
exterior of the shell and the sealing member is fluidly
disconnected from the second fluid in the second tank.
17. An exhaust gas cooler according to claim 16 wherein the sealing
member is adjacent a portion of the second tank that is fluidly
disconnected from the second fluid.
18. An exhaust gas cooler according to claim 12 wherein the tube
sheets, the tubes, and the second tank are removable from the shell
as a unitary structure.
19. An exhaust gas cooler according to claim 12 wherein the first
tube sheet is bolted to the shell.
20. An exhaust gas cooler according to claim 12 further comprising
a resilient member disposed between the shell and the first tube
sheet such that the first tube sheet is flexibly connected to the
shell.
21. An exhaust gas cooler according to claim 12 wherein the shell
defines an inner surface portion proximate the second end having a
diameter that corresponds in size to an outer surface of the second
tank, the inner surface portion flaring radially outward in a
direction toward the first end of the shell.
22. A heat exchanger with a removable core, the heat exchanger
comprising: a shell means for receiving a first fluid; first and
second tank means for receiving a second fluid, the first and
second tank means being configured proximate to first and second
ends of the shell means respectively, and the shell means and
second tank means defining a junction therebetween; a connection
means for fluidly connecting the first and second tank means; and
sealing means for preventing the first fluid from flowing through
the junction between the shell means and the second tank means,
wherein the connection means and the second tank means are
configured to adjust axially relative to the shell means and to be
removed through the first end of the shell means.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to a heat exchanger
with a removable core and, more particularly, the invention relates
to a heat exchanger with a tank that is axially adjustable, for
example, as the components of the heat exchanger expand or contract
due to thermal changes.
BACKGROUND OF THE INVENTION
[0002] Heat exchangers are often used to transfer thermal energy
between two or more fluids. For example, hot engine fluids such as
oil, water, and exhausted combustion gases that are generated by or
circulated through an internal combustion engine can be circulated
through a heat exchanger to transfer thermal energy to a coolant,
thereby cooling the hot engine fluid. The heat exchanger can be
subjected to significant thermal stresses due to the extreme
temperatures and temperature variations occurring in the heat
exchanger. The thermal stresses can interfere with the operation of
the heat exchanger and shorten the life of the heat exchanger,
thereby increasing the risk of damage to other components and
requiring costly repair or replacement.
[0003] One conventional heat exchanger features a tubular outer
shell with opposing tanks mounted at the two opposite open ends of
the shell. A plurality of tubes extend through the outer shell to
connect the tanks. A first fluid can be circulated between the
tanks and a second fluid can be circulated through the shell so
that thermal energy is exchanged between the two fluids through the
walls of the pipes. One of the tanks can be partially defined by a
floating plate to which the tubes are attached.
[0004] The floating plate is not rigidly connected to the shell but
rather is sealed to the inner surface of the shell by an o-ring so
that the tube moves freely in the axial direction of the shell. The
tank with the floating plate can be connected to the shell so that
the floating plate moves axially within the tank, or the tank can
be connected to the floating plate, i.e., not connected to the
shell, so that the entire tank moves axially with the floating
plate. In either case, as the tubes are heated or cooled and change
in length, the floating plate moves axially accordingly, thereby
reducing thermal stresses in the tubes.
[0005] The increased size and complexity of heat exchangers
generally increases the costs of manufacture and maintenance. As
the number of components and welds or other joints increases, the
likelihood of manufacturing errors generally increases. Further,
disassembly of a heat exchanger can be difficult and time
consuming. For example, if the tubes or other internal components
fail, disassembly requires the removal of the tanks from the tubes
and removal of the tubes from the shell. In some cases, the cost
and complexity of disassembly makes repairs impractical.
[0006] Thus, there exists a need for an improved heat exchanger
that reduces thermal stresses. Preferably, the number of components
and required joints should be minimized to simplify the manufacture
of the heat exchanger. Further, a core portion of the heat
exchanger should be removable during disassembly of the heat
exchanger.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0007] Having thus described the invention in general terms,
reference will now be made to the accompanying drawings, which are
not necessarily drawn to scale, and wherein:
[0008] FIG. 1 is section view illustrating a heat exchanger with a
removable core according to one embodiment of the present
invention;
[0009] FIG. 2 is an enlarged view illustrating the sealing member
of the heat exchanger of FIG. 1, as indicated in FIG. 1; and
[0010] FIG. 3 is a section view of a sealing member according to
another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The present invention now will be described more fully
hereinafter with reference to the accompanying drawings, in which
some, but not all embodiments of the invention are shown. Indeed,
this invention may be embodied in many different forms and should
not be construed as limited to the embodiments set forth herein;
rather, these embodiments are provided so that this disclosure will
satisfy applicable legal requirements. Like numbers refer to like
elements throughout.
[0012] Referring now to FIG. 1, there is shown a heat exchanger
according to one embodiment of the present invention. The heat
exchanger 10 has an outer shell 20 and a replaceable core 40 that
is disposed at least partially therein, the core 40 being
structured to allow for thermal expansion independent of the shell
20. The heat exchanger 10 can be, for example, an exhaust gas
cooler (EGC) as shown in FIG. 1 that uses a fluid coolant such as
water or oil to cool hot exhaust gases flowing from an engine. The
heat exchanger 10 can similarly be used for cooling or heating
other fluids, including liquids and gases.
[0013] The shell 20 of the heat exchanger 10 is tubular and extends
axially from a first end 22 to a second end 24 and defines an
interior space 26 and one or more ports 28, 30 for passing a fluid,
for example, the coolant. As shown in FIG. 1, the inlet coolant
port 28 receives the coolant, and the coolant then flows through
the shell 20 and exits through the outlet coolant port 30. Baffles
16 can be provided within the shell to direct the flow and increase
the speed of the coolant in the shell 20. The shell 20 can be
cylindrical, as shown, or the shell 20 can have a cross-sectional
shape defined by other polygons, such as a square. First and second
tanks 50, 60 are provided at the respective ends 22, 24 of the
shell 20. Tubes 80 or other fluid connection means that extend
between the first and second tanks 50, 60 provide fluid
communication therebetween for another fluid, for example, the hot
exhaust gas. As the hot exhaust gas flows between the tanks 50, 60
through the tubes 80, thermal energy from the hot exhaust gas is
transferred to the coolant, thereby cooling the hot exhaust
gas.
[0014] The first tank 50 is defined by a first tube sheet 52 and a
tank member 54. The tube sheet 52 defines a plurality of holes,
which correspond to the tubes 80, so that the tubes 80 are fluidly
connected to the tank 50. The tank 50 also has a port 56 through
which the hot exhaust gas from the engine enters the heat exchanger
10. The tube sheet 52 and the tank member 54 are connected to the
shell 20, for example, by bolts 12 that extend through the tank
member 54, through the tube sheet 52, and into threaded holes in
the shell 20. The bolts 12 are shown to extend in a direction
parallel to the axial direction of the shell 20 in FIG. 1, though
other configurations are also possible. For example, the bolts 12
can extend transverse to the axial direction of the shell 20 or at
an angle to the axial direction. Alternatively, the tank 50 can be
connected to the shell 20 by other connection devices, such as
clips, clamps, and the like. In addition, gaskets 14 can be
provided between the tube sheet 52 and the shell 20 and/or between
the tube sheet 52 and the tank member 54. The gaskets 14, which can
be formed of stainless steel or other resilient and/or corrosion
resistant materials, seal the connections between the tube sheet
52, shell 20, and tank member 54. Further, the gaskets 14 provide a
flexible connection between the tube sheet 52, shell 20, and tank
member 54 to accommodate slight changes in the shape or size of the
components, for example, as the components heat and cool.
[0015] Similarly, the second tank 60 is defined by a second tube
sheet 62 and a second tank member 64. The second tube sheet 62 also
defines a plurality of holes that correspond to the tubes 80 so
that the tubes 80 fluidly connect the second tank 60 to the first
tank 50. The second tank 60 has a port 66 through which the cooled
exhaust gas can exit the heat exchanger 10. Thus, the exhaust gas
enters the first tank 50 through the first port 56, flows through
the tubes 80 in the shell 20 to the second tank 60, and exits the
heat exchanger 10 through the second port 66. In other embodiments,
the exhaust gas can flow in the opposite direction through the heat
exchanger 10. Further, the exhaust gas can flow in both directions
between the tanks 50, 60 and can flow through the tubes 80 multiple
times before exiting the heat exchanger 10, as is known in the art.
For example, the first tank 50 can be partitioned into two
portions, and the second port 66 can be provided on the first tank
50 so that the exhaust gas flows into a first portion of the first
tank 50, through some of the tubes 80 to the second tank 60, and
then through other tubes 80 to the second portion of the first tank
50, where the exhaust gas exits the heat exchanger 10 through the
second port 66. Thus, the exhaust gas can be made to flow through
the shell 20 twice, thereby increasing the thermal transfer between
the exhaust gas and the coolant.
[0016] The second tank 60 is not rigidly connected to the shell 20.
Instead, the second tank 60 is configured to adjust axially
relative to the shell 20 as the tubes 80 thermally expand or
contract and change length, or the components of the heat exchanger
10 otherwise change size or shape. As shown in FIG. 2, the second
tank member 64 is formed of a tubular portion 68 and an end portion
70, which are welded together or otherwise connected, for example,
by bolts, clamps, an interference fit, or a mechanical interlock
such as a snap fit. The second tube sheet 62 is connected to the
tubular portion 68, and the tubes 80 are connected to the second
tube sheet 62. One or more sealing members 72, such as o-ring
seals, are disposed between the shell 20 and the tubular portion 68
of the second tank.
[0017] The sealing members 72 can be disposed in grooves 74 defined
on an inner surface 32 of the shell 20. The sealing members 72
fluidly disconnect the interior space 26 from a space exterior to
the shell, thereby preventing the coolant in the shell 20 from
exiting the shell 20 through a junction between the shell 20 and
the second tank 60. The junction of the shell 20 and the second
tank 60 that is sealed by the sealing members 72 can define an
annular space therebetween or the shell 20 and the second tank 60
can be in contact.
[0018] The second tank 60, including the tank member 64 and the
tube sheet 62, is connected to the tubes 80 to form the core 40,
which is removable from the shell 20, for example, for repair,
maintenance, or replacement. Advantageously, the second tank 60 can
be smaller than the inside diameter of the shell 20 so that the
core 40 can be removed as a unitary structure from the first end 22
of the shell 20. For example, the core 40 can be removed by
removing the bolts 12 and the first tank member 50, then sliding
the second tank 60 axially toward the first end 22 of the shell 20
and removing the second tank 60 with the tubes 80, baffles 16, and
the first tube sheet 52. Thus, the core 40, comprising the second
tank member 64, tube sheets 52, 62, tubes 80, and baffles 16 can be
fixedly attached, e.g., by weld joints, braze joints, solder
joints, and the like, and can be removed from the shell 20 as a
unitary structure. Further, the exhaust gas can be fluidly
contained in the tanks 50, 60 and tubes 80 so that the exhaust gas
does not contact the sealing members 72, thereby reducing the
heating effect of the exhaust gas on the sealing members 72. As
shown in the figures, the sealing members 72 may also
advantageously be located adjacent a portion of second tank member
64 that is not directly exposed to the exhaust gas, but is rather
exposed to fluid coolant and/or a space exterior to the shell.
[0019] As shown in FIG. 3, the sealing members 72 can be disposed
on the second tank, for example, in grooves 76 defined by the
tubular portion 68 of the tank member 64 of the second tank 60. The
inner surface 32 of the shell 20 can have a diameter that
corresponds in size to the outer surface of the second tank 60, for
example, the tubular portion 68 thereof, so that the sealing
members 72 seal the inner surface 32 to the outer surface of the
second tank 60. Further, a portion 34 of the inner surface 32
proximate the second end 24 of the shell 20 can flare radially
outward in a direction toward the first end 22 of the shell 20,
i.e., the inner surface portion 34 is tapered toward the second end
24. Thus, the second tank 60 can easily be slid axially through the
shell 20 during assembly, and the inner surface portion 34 provides
a close fit with the second tank 60 so that the sealing members 72
seal therebetween.
[0020] The shell 20 can be a cast member, for example, formed of
cast steel, and the inner surface portion 34 can be a machined
surface on the shell 20 with precise tolerances. The shell casting
can also define other features such as the ports 28, 30, grooves
74, a bracket 36 or other device for mounting the heat exchanger
10, and the like. The other components, such as the tank members
54, 64, tube sheets 52, 62, and baffles 16, can be formed of
corrosion resistant materials such as stainless steel, and can be
stamped, machined, or otherwise formed.
[0021] Many modifications and other embodiments of the invention
set forth herein will come to mind to one skilled in the art to
which this invention pertains having the benefit of the teachings
presented in the foregoing descriptions and the associated
drawings. Therefore, it is to be understood that the invention is
not to be limited to the specific embodiments disclosed and that
modifications and other embodiments are intended to be included
within the scope of the appended claims. Although specific terms
are employed herein, they are used in a generic and descriptive
sense only and not for purposes of limitation.
* * * * *