U.S. patent application number 09/822776 was filed with the patent office on 2001-11-01 for passive mounted lining system.
This patent application is currently assigned to Quiet Systems International, LLC. Invention is credited to Crow, Daniel P., Littmann, David F., Sinha, Biswanath.
Application Number | 20010035003 09/822776 |
Document ID | / |
Family ID | 26889305 |
Filed Date | 2001-11-01 |
United States Patent
Application |
20010035003 |
Kind Code |
A1 |
Sinha, Biswanath ; et
al. |
November 1, 2001 |
Passive mounted lining system
Abstract
In order to provide for coupling between the shell and the
liner, a passive mounting system is provided. The passive mounting
system uses indirect metal contact between the liner or liner panel
and the shell. This design serves two main objectives: to minimize
heat transfer between the hot gases and ultimately the exterior of
the exhaust system; and to provide flexibility and mobility between
liner components for changing stress and strain conditions, whether
thermally related or otherwise. A passive mounted lining system
comprising an outer shell, a liner support channel having a bolt
slide void, a partially threaded bolt with a predetermined length
of threads, and a series of thermal expansion compatible nuts,
bolts, and washers, along with a liner channel support leg is
disclosed. A method of mounting a liner system is also disclosed,
the method comprising providing an outer shell, mounting on the
outer shell a liner support channel having a bolt slide void,
providing a partially threaded bolt with a predetermined length of
threads in sliding engagement with the bolt slide void, mounting
successively on the bolt a series of thermal expansion compatible
nuts, bolts, spacers, and washers. The method further comprises
tightening the nut on the partially threaded bolt and peening
exposed threads that extend vertically past the nut to prevent the
nut from loosening.
Inventors: |
Sinha, Biswanath; (Madison,
WI) ; Crow, Daniel P.; (Verona, WI) ;
Littmann, David F.; (Stoughton, WI) |
Correspondence
Address: |
RYAN KROMHOLZ & MANION, S.C.
P.O. BOX 26618
Milwaukee
WI
53226
US
|
Assignee: |
Quiet Systems International,
LLC
|
Family ID: |
26889305 |
Appl. No.: |
09/822776 |
Filed: |
March 30, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60193742 |
Mar 31, 2000 |
|
|
|
Current U.S.
Class: |
60/796 ;
60/752 |
Current CPC
Class: |
F05D 2250/281 20130101;
F02C 7/24 20130101; F01D 25/145 20130101; F05D 2260/941 20130101;
F05D 2300/5024 20130101; F05D 2260/94 20130101; F01D 25/265
20130101; F05B 2260/301 20130101 |
Class at
Publication: |
60/39.31 ;
60/752 |
International
Class: |
F02C 007/00 |
Claims
What is claimed is:
1. A passive mounted lining system comprising: an outer shell; a
liner support channel having a bolt slide void; a partially
threaded bolt with a predetermined length of threads; a first
washer with a void disposed thereon; a liner panel having a liner
panel void; a second washer with a void disposed thereon; a nut
with a void disposed thereon; wherein the liner support channel is
carried by the outer shell; and wherein the partially threaded bolt
is slidably engagable with the bolt slide void, and the bolt
carries the first washer, the liner panel, and the second washer;
and wherein the nut is threadedly engageable with the bolt.
2. A passive mounted lining system according to claim 1, the
passive mounted lining system further comprising insulation at
least partially within the liner support channel.
3. A passive mounted lining system according to claim 1, wherein
the nut is coupled to the bolt by a weld.
4. A passive mounted lining system according to claim 1, wherein at
least a portion of the predetermined length of threads is deformed
after threadedly engaging the nut to the bolt.
5. A passive mounted lining system according to claim 1, wherein
the bolt slide void is oriented substantially parallel to a
direction of primary air flow within an exhaust system.
6. A passive mounted lining system according to claim 1, wherein
the bolt slide void is oriented substantially perpendicular to a
direction of primary air flow within an exhaust system.
7. A plurality of passive mounted lining systems according to claim
1, wherein the bolt slide void is oriented randomly to a direction
of primary air flow within an exhaust system.
8. A passive mounted lining system comprising at least two of the
liner support channels of claim 1.
9. A passive mounted lining system according to claim 8, wherein
the liner support channels are positioned in a spaced apart
relationship.
10. A passive mounted lining system according to claim 9 wherein
liner support channels are oriented in an alternating
arrangement.
11. A passive mounted lining system according to claim 10 wherein
the alternating arrangement is alternating between substantially
perpendicular to a direction of primary air flow within an exhaust
system and substantially parallel to the direction of primary air
flow within the exhaust system.
12. A passive mounted lining system according to claim 1, the
passive mounted lining system further comprising an insulating
layer between the outer shell and the liner panel.
13. A passive mounted lining system according to claim 1, wherein
the outer shell, the liner support channel, the partially threaded
bolt, the first washer, the liner panel, the second washer, and the
nut react complimentary to a change of air temperature within an
exhaust system.
14. A passive mounted lining system according to claim 1, wherein
the outer shell, the liner support channel, the partially threaded
bolt, the first washer, the liner panel, the second washer, and the
nut react complimentary to at least one of the group comprising a
change of air temperature within an exhaust system, a change of
broadband exhaust noise within the exhaust system, a change of
low-frequency noise within the exhaust system, rupture stresses,
creep stresses, and earthquakes.
15. A passive mounting system according to claim 1, wherein the
outer shell is less than 140 F. during operation of an exhaust
system carrying the passive mounting system.
16. A passive mounting system according to claim 1, the passive
mounting system further comprising a spacer carried by the
bolt.
17. A passive mounting system according to claim 1, wherein a
lubricant is carried by at least one of the partially threaded
bolt, the first washer, the liner panel, the second washer, and the
nut.
18. A passive mounting system according to claim 17 wherein the
lubricant is graphite.
19. A passive mounting system according to claim 1, wherein the
liner panel void is larger than a diameter of the bolt.
20. A method of mounting a liner system onto a shell, the method
comprising: providing an outer shell; mounting on the outer shell a
liner support channel having a bolt slide void; providing a
partially threaded bolt with a predetermined length of threads in
sliding engagement with the bolt slide void; providing a liner
panel having a liner panel void; mounting successively on the bolt
a first washer, the liner panel through the liner panel void, a
second washer, and a nut.
21. The method of claim 20, the method further comprising
tightening the nut on the partially threaded bolt.
22. The method of claim 21, the method further comprising peening
exposed threads that extend vertically past the nut.
23. The method of claim 21, the method further comprising welding
the nut to the bolt.
24. A coupling system between a shell and a liner of an exhaust
system, the coupling system comprising: a liner support channel; a
plurality of mounting system components carried by the liner
support channel; a means for retaining the mounting system
components in a stacked relationship with the liner support
channel; wherein the shell carries the liner support channel; and
wherein the means for retaining the plurality of mounting system
components in a stacked relationship also retains at least a
portion of the liner.
25. A coupling system according to claim 24, the liner support
channel further comprising a means for accepting the means for
retaining the mounting system components in a stacked relationship
with the liner support channel.
26. A coupling system according to claim 24, the coupling system
further comprising an insulation layer between the shell and the
liner.
27. A coupling system according to claim 24, the coupling system
further comprising an insulation layer between the shell and at
least a portion of the liner support channel.
28. A coupling system according to claim 24, the plurality of
mounting system components comprising: a lock washer, a first
washer, a spacer, and a second washer.
29. A coupling system according to claim 28, wherein at least a
portion of the liner is carried between the lock washer and the
second washer.
30. A coupling system according to claim 28, the lock washer
comprising a planar body with a void disposed thereon, and a lip
coupled substantially perpendicularly to said planar body on an
edge of the planar surface.
31. A coupling system according to claim 30, wherein the lip is
oriented facing a direction of primary air flow within an exhaust
system carrying the coupling system.
32. A coupling system according to claim 24, wherein the plurality
of mounting system components react complimentary to at least one
of the group comprising a change of air temperature within an
exhaust system, a change of broadband exhaust noise within the
exhaust system, a change of low-frequency noise within the exhaust
system, rupture stresses, creep stresses, and earthquakes.
33. A coupling system according to claim 24, wherein the plurality
of mounting system components and the liner and the shell react
complimentary to at least one of the group comprising a change of
air temperature within an exhaust system, a change of broadband
exhaust noise within the exhaust system, a change of low-frequency
noise within the exhaust system, rupture stresses, creep stresses,
and earthquakes.
34. A coupling system according to claim 24, wherein the shell is
less than 140.degree. F. during operation of an exhaust system
carrying the coupling system.
35. A passive mounted lining system comprising at least two of the
coupling systems of claim 24.
36. A passive mounted lining system according to claim 33 wherein
liner support channels are not uniformly oriented in relation to a
direction of primary air flow within an exhaust system carrying the
passive mounted lining system.
Description
FIELD OF THE INVENTION
[0001] This invention relates to liner and shell of thermally
insulated walls that are used in the lined exhaust systems used to
carry or direct hot air or exhaust gases.
BACKGROUND OF THE INVENTION
[0002] Typically, hot gases are produced as a result of a reaction
or thermodynamic process such as those that are produced from
combustion engines. One result of a combustion process is hot gases
which range from temperatures between 750.degree. F. and
2000.degree. F. As these gases exit the thermodynamic process, they
are exhausted into the atmosphere, a duct system and/or chimney or
stack depending on the application. These are considered to be
types of exhaust systems. Because these systems operate from
several hours a day up to 24 hours per day for 20 or more years, it
is imperative that the exhaust system components have the
durability to withstand the extended and severe operating
conditions to which they are subjected.
[0003] Generally, in industrial and commercial applications, a duct
system and/or chimney or stack, depending on the application is
accessible to workers. For safety purposes, surface temperature of
equipment that is accessible to workers should be limited
140.degree. F. as per ASTM C1055-99, which is recognized as the
national consensus standard. This means that if the gases inside
the exhaust system are greater than the allowable exterior duct
temperature, the duct needs to be either cooled, shielded or
insulated.
[0004] One method of insulating exhaust systems is through the use
of a liner. A liner is a barrier that protects insulation applied
inside a duct shell. Typically the liner is coupled to the shell
while retaining the insulation necessary to reduce the heat
transmitted to the exhaust system shell exterior. The liner is
directly exposed to the heat from the hot gases being directed by
the exhaust system. Since the liner is exposed to extremely high
temperatures, thermal expansion often creates unusual problems such
as warping and buckling.
[0005] Typical stresses in an exhaust system include broadband
exhaust noise, low-frequency noise, thermal expansion and
contraction, changes in operating conditions, rupture and creep
stresses, earthquakes and other various environmental, acoustical
and mechanical stresses and strains.
[0006] In order to support or mount a liner or liner panel in the
exhaust system, the primary method is active mounting. Active
mounting uses direct coupling by through metal contact between the
liner and the inside of the shell. However, liners with active
mounting may not respond well over time to changing stresses and
strains as a result of direct exposure to heat.
SUMMARY OF THE INVENTION
[0007] In order to provide for coupling between the shell and the
liner, a passive mounting system is provided. The passive mounting
system uses indirect metal contact between the liner or liner panel
and the shell. The through-metal contact, or direct contact, is
insignificant for this method of mounting.
[0008] This design serves two main objectives: to minimize heat
transfer between the hot gases and ultimately the exterior of the
exhaust system; and to provide flexibility and mobility between
liner components for changing stress and strain conditions, whether
thermally related or otherwise.
[0009] A passive mounted lining system comprising an outer shell, a
liner support channel having a bolt slide void, a partially
threaded bolt with a predetermined length of threads, a lock washer
with a void disposed thereon, a first washer with a void disposed
thereon, a spacer with a void disposed thereon, a first graphite
layer with a void disposed thereon, a liner panel having a liner
panel void, a second graphite layer with a void disposed thereon, a
second washer with a void disposed thereon, a nut with a void
disposed thereon, wherein the liner support channel is carried by
the outer shell, and wherein the partially threaded bolt is
slidably engagable with the bolt slide void, and the bolt carries
the lock washer, the first washer, the spacer, the first graphite
layer, the liner panel, the second graphite layer, the second
washer, and wherein the nut is threadedly engageable with the
bolt.
[0010] One objective of the present invention is for the disclosed
method and apparatus to capably withstand seismic loads, such as
those possible in seismic zones 3 and 4 as described by ANSI and
ASCE design standards.
[0011] A method of mounting a liner system is also disclosed, the
method comprising providing an outer shell, mounting on the outer
shell a liner support channel having a bolt slide void, providing a
partially threaded bolt with a predetermined length of threads in
sliding engagement with the bolt slide void, mounting successively
on the bolt a lock washer, a washer, a spacer, a graphite layer,
providing a liner panel having a liner panel void, mounting the
liner panel on the bolt through the liner panel void, mounting on
the bolt a graphite layer, a washer, and a nut. The method further
comprises tightening the nut on the partially threaded bolt, while
not binding the liner panel. The method further comprises peening
exposed threads that extend vertically past the nut to prevent the
nut from loosening, or welding one face of the nut to the second
washer to accomplish the same objective. It should be noted that
the nut, the washer, the liner panel, the graphite layer, the
graphite layer, the spacer, the washer and the lock washer are all
provided with voids larger in diameter than the bolt.
DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a cross sectional view of a typical exhaust stack,
showing an outer shell, a liner or liner panels, and a liner panel
support leg;
[0013] FIG. 2 is a side cross-sectional view of a passive mounting
system;
[0014] FIG. 2A is a perspective view of a lock washer;
[0015] FIG. 3 is an exploded perspective view of a passive mounting
system;
[0016] FIG. 3A is a side perspective view of an alternate plurality
of passive mounting system components;
[0017] FIG. 3B is a side-elevational view of a liner support
channel;
[0018] FIG. 4 is a side view of vertically stacked inside shells
showing possible passive mounting system orientations and
locations;
[0019] FIG. 5 is a perspective view with portions broken away, of a
passive mounting system.
DETAILED DESCRIPTION
[0020] Although the disclosure hereof is detailed and exact to
enable those skilled in the art to practice the invention, the
physical embodiments herein disclosed merely exemplify the
invention which may be embodied in other specific structure. While
the preferred embodiment has been described, the details may be
changed without departing from the invention, which is defined by
the claims.
[0021] Referring now to FIG. 1 a cross sectional view of a typical
exhaust system, showing an outer shell 22, a liner panel support
leg 24, and a liner panel 20 or liner panels is shown.
[0022] For the purposes of describing the three dimensional aspects
of the present invention, primary exhaust air flow direction will
be in the y-direction, from the source to the atmosphere. In many
instances, the y-direction will be vertical in an exhaust stack.
The x-direction and the z-direction are each perpendicular to the
y-direction, and in many instances will describe a horizontal plane
in an exhaust stack. Planes are described as an xy-plane, an
xz-plane, and a yz-plane. Mobility of the liner panels is desired
in all three planes: the xy-plane, xz-plane, and yz-plane.
[0023] A passive mounting system, shown in FIG. 2, couples the
mobile liner panel 20 with the fixed outer shell 22. The passive
mounting system provides axial and radial mobility, and minimizes
heat transfer between the hot gas and the outer shell.
[0024] Referring now to FIG. 2, a side cross-sectional view of a
passive mounting system 10 is shown. The passive mounting system 10
allows the outer shell 22 of an exhaust system to be coupled
passively with liner covers 26 (not shown) and a liner panel 20
through the liner panel support leg 24. Coupled to the outer shell
22 is a liner support channel 46. A bolt 30 with threads 31, when
tightened with a nut 32, secures in sequential order as shown: a
washer 34, a layer 36, the liner panel 20, a layer 38, a spacer 40,
a washer 42, and a lock washer 44.
[0025] It is important that the components of the passive mounting
system 10 react similarly to changing stress and strain conditions,
such as heat. It is also important that the components of the
passive mounting system minimize heat transfer along the yz-plane
in the x-direction as shown in FIG. 2, or from top to bottom of the
components shown in FIG. 2. For these reasons, components with
compatible materials in relation to thermal expansion coefficients
are preferable. For example but not by way of limitations, it has
been found that suitable materials for the washer 34 and the spacer
40 are UNS S40930, or AISI 409, or AISI 304. 12 gauge material for
liner panels 20 have been found to provide sufficient thermal
resistance and strength to perform suitably under the stresses and
strains common in exhaust system components. More particularly a
stabilized ferretic stainless steel such as Allegheny 409HP, UNS
S40930, or Armco 409, UNS S40920 may perform suitably.
[0026] The layers 36 and 38 are preferably comprised of materials
that transmit heat laterally, or disperse heat, instead of
transmitting the heat. Graphite has been found to perform suitably
and advantageously for this purpose for the layer 36 and the layer
38. The washer 42 has been found to perform suitably when
fabricated from ceramic paper, such as G/I-83 available from
Gaskets, Inc. The ceramic paper is heat resistant, yet compressible
enough to allow the components of the passive mounting system 10 to
move slightly in response to changing stress and strain conditions.
The lock washer 44 has been found to perform suitably when
fabricated from carbon steel in 12 gauge.
[0027] In order to insulate the space inside the liner support
channel 46, an insulation block 60 is provided. Insulation block 60
is preferably dense enough to partially hold bolt 30 in place and
remain within liner support channel 46, yet soft enough to slightly
deform underneath the head of bolt 30. One material that performs
these functions suitably is Fibrex brand FBX 1900 insulation.
[0028] In order to insulate between successive passive mounts,
which in use will be described later, insulation 62 is provided.
Insulation 62 is shown in FIG. 2 as three distinct layers, although
any different number of layers may perform suitably. Stratification
and different orientation of insulation 62 is preferable to
accommodate expansion and contraction as the passive mounting
system 10 responds to changing stresses and strains. For instance,
the insulation 62 may be required to compress and expand 5-10% or
more when the passive mounting system 10 responds to rising and
lowering temperatures. One insulation material that has suitable
heat and compression characteristics is ceramic fiber.
[0029] This combination of mounting system 10 component materials
have been found advantageous to providing mobility, perpendicular
to the main gas flow direction, as well as axial mobility.
[0030] Referring now to FIG. 2A, an alternative, preferred
embodiment of a lock washer 44a is shown. In this embodiment,
overhanging lips 1' and 1" are provided in the x-direction to
prevent the bolt 30 from disengaging with the liner support channel
46. When employed in the plurality of components in the x-direction
as shown in FIG. 3, the overhanging lips 1' and 1" advantageously
brace against rotation in the y-z plane, minimizing wear on
components of the passive mounting system 10. The lips 1' and 1"
are oriented so that one of the lips 1' or 1" covers at least a
portion of bolt slide void 50. The other lip, the lip does not
cover at least a portion of bolt slide void 50, braces against
movement in the y-direction by bracing itself against the liner
support channel 46.
[0031] Referring now to FIG. 3, an exploded perspective view of the
passive mounting system 10 is shown, with a plurality of passive
mounting system components shown roughly on the y-z planes. The
components are preferably assembled in vertical order starting with
the bolt 30, and stacking components vertically as shown. The
layers 36 and 38 are provided for lubricity in order to minimize
component wear and tear for those components that contact the liner
panel support leg 24. Alternatively, in place of the layers 36 and
38, during assembly, the washer 34 and spacer 40 may be coated with
lubricant to accomplish this objective.
[0032] Referring now to FIG. 3A, a side perspective view of an
alternate plurality of passive mounting system components is shown,
with portions of components cut away. In this embodiment, select
components of the previously described plurality of passive
mounting system components have been omitted as can be seen by
comparing FIG. 3 with FIG. 3A. In this alternate plurality of
passive mounting system components, the components are arranged in
the following order on the yz-plane in increasing x-direction,
about the bolt 30 with threads 31: the liner support channel 46,
the lock washer 44, washer 42, the spacer 40, the liner panel 20,
the washer 34, and the nut 32. This arrangement may be preferable
to simplify assembly of the components.
[0033] As FIGS. 3 and 3A show, the bolt 30 preferably has threads
31 only partially along the length of the bolt 30. The partial
threading prevents the nut 32 from over-tightening during assembly
to ensure axial mobility of liner panel 20 when exposed to heat,
vibration and other noises common in the exhaust system. In order
to prevent loosening of the nut 32 when exposed to the same forces,
the threads 31 are preferably mechanically deformed, or peened,
after the nut 32 has been tightened during assembly. Alternatively,
welding of the nut to the bolt or washer, or any other means for
preventing movement of the nut relative to the bolt may be
performed. SAE J429, Grade 5 or ASTM A449 are materials that are
suitable for construction of the bolt 30.
[0034] As FIG. 3 also shows, the liner support channel 46 is
provided with a bolt slide void 50 in order that the longer bolt 30
may be engaged with the liner support channel 46 which is shorter
than the bolt. Also, as will be described later, the liner panel
void 48 provides mobility in the yz-plane. Also as FIG. 3 shows,
the surface contact between the liner support channel 46 and the
outer shell 22 is preferably minimized by providing small
cross-sectional contact between the outer shell 22 and the liner
support channel 46. As also shown on FIG. 3, the liner panel void
48 is shaped larger than voids provided on the washers 34 and 44
and washer 42 and spacer 40. The larger liner panel void 48 reduces
potentially destructive shear forces that could result as the liner
panel 20 moves in relation to the outer shell 22 during periods of
above ambient heat exposure.
[0035] The larger liner panel void 48 is provided such that the
liner panel 20 can move relative to the liner support channel 46
without shearing the bolt 30. This larger liner panel void 48 also
eases assembly of the components by allowing fabrication in the
yz-plane that an otherwise smaller sized void 48 would provide.
Panels 20 are thus in free floating relationship.
[0036] Referring now to FIG. 3B a side-elevational view of a liner
support channel 46 is shown, with portions of outer shell 22 broken
away. An alternate, preferred bolt slide void 50A is provided on
liner support channel 46, such that liner support channel 46 is
continuously coupled with outer shell along two lines in the
yz-plane. Comparing the bolt slide void 50A shown in FIG. 3B with
the bolt slide void 50 shown in FIG. 3, it can be seen that the
preferred bolt slide void 50A shown in FIG. 3B is continuously
coupled with the outer shell 22 in the z-direction. It has been
found that this design improves structural strength of the liner
channel 46.
[0037] Referring now to FIG. 4, an inside to outside view of
vertically stacked shells 22 showing possible passive mounting
system 10 orientations and locations is shown. Viewing FIG. 4, a
plurality of passive mounting systems 10 are disposed on a
plurality of vertically stacked shells 22. The passive mounting
systems 10 are provided in spaced-apart relationship to accommodate
liner covers 26 (shown in FIG. 5) provided between adjacent liner
panels 20. The mounting systems 10 are spaced apart in relation to
receive liner panels 20 and liner covers 26. The geometry of the
liner panels and liner covers may vary, thus controlling the
specific geometry of the mounting system 10 deployment on the
shells 22.
[0038] As can be seen from the exploded portion of FIG. 4, it is
preferable that the passive mounting systems 10, and in particular
the liner support channels 46 and bolt slide voids 50 be oriented
differently between adjacent mounting systems 10. One pattern of
orienting adjacent mounting systems 10 is shown in FIG. 4, where
orientations are alternated in a 90 relationship between each two
adjacent mounting systems 10. In one orientation, the liner channel
46, and particularly the bolt slide void 50 (shown) or bolt slide
void 50A (not shown) is oriented to accept the bolt 30 from the
direction of primary exhaust air flow direction in the y-direction.
In an adjacent orientation for the mounting system 10, the liner
channel 46, and particularly the bolt slide void 50 (shown) or bolt
slide void 50A (not shown) is oriented to accept the bolt 30 from
roughly 90.degree. of the direction of primary exhaust air flow
direction in the y-direction. This is only one preferred pattern of
orienting adjacent mounting systems 10. Any pattern of orienting
adjacent mounting systems 10 is acceptable, based on the preference
of the fabricator.
[0039] This arrangement allows axial mobility, yet prevents
mobility to the degree that the bolt 30 would become separated from
the liner support channel 46. The 90 relationship is preferable for
welders as it allows spacing to be measured accurately from edges
of shells 22.
[0040] Referring now to FIG. 5, coupled with each liner panel 20 is
an attachment mechanism, preferably a z-clip 28 to couple each
liner panel 20 with one or more liner covers 26. In this manner
each liner cover is coupled by z-clips to adjacent liner panels 20
and mounting systems 10. Additionally, it is preferable to couple
liner covers 26 to liner panels 20. Preferably, this coupling is a
weld. Suitable welds are stitch welds or fillet welds. One stitch
weld that has performed particularly well is a 2 on 10 stitch weld.
As FIG. 5 shows, the welds W are preferably positioned on an
upstream portion of liner covers 26, coupled to a downstream
portion of liner panels 20.
[0041] A method of mounting a liner system is also shown in FIGS.
2-5. The method comprises providing an outer shell 22, mounting on
the outer shell 22 a liner support channel 46 having a bolt slide
void 50, providing a partially threaded bolt 30 with a
predetermined length of threads 31 in sliding engagement with the
bolt slide void 50, mounting successively on the bolt 30 a lock
washer 44, a washer 42, a spacer 40, a graphite layer 38, providing
a liner panel 20 having a liner panel void 48, mounting the liner
panel 20 on the bolt 30 through the liner panel void 48, mounting
on the bolt 30 a graphite layer 36, a washer 34, and a nut 32. The
method further comprises tightening the nut 32 on the partially
threaded bolt. The method further comprises peening exposed threads
31 that extend vertically past the nut 32 to prevent the nut 32
from loosening. It should be noted that the nut 32, the washer 34,
the graphite layer 36, the graphite layer 38, the spacer 40, the
washer 42 and the lock washer 44 are all provided with voids larger
in diameter than the bolt 30.
[0042] The foregoing is considered as illustrative only of the
principles of the invention. Furthermore, since numerous
modifications and changes will readily occur to those skilled in
the art, it is not desired to limit the invention to the exact
construction and operation shown and described. While the preferred
embodiment has been described, the details may be changed without
departing from the invention, which is defined by the claims.
* * * * *