U.S. patent application number 13/792620 was filed with the patent office on 2014-09-11 for pressure masking systems and methods for using same in treating techniques.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. The applicant listed for this patent is GENERAL ELECTRIC COMPANY. Invention is credited to Michael Anthony DePalma, Mark Lawrence Hunt.
Application Number | 20140251951 13/792620 |
Document ID | / |
Family ID | 50238169 |
Filed Date | 2014-09-11 |
United States Patent
Application |
20140251951 |
Kind Code |
A1 |
Hunt; Mark Lawrence ; et
al. |
September 11, 2014 |
PRESSURE MASKING SYSTEMS AND METHODS FOR USING SAME IN TREATING
TECHNIQUES
Abstract
Systems and methods of treating, e.g., stripping and coating, a
target surface of an article including a passageway are disclosed.
The systems may fluidly connect a pressure masker including
pressurized masking fluid to a first side of the passageway,
passing the pressurized masking fluid through the passageway from
the first side to a second side including the target surface, and,
submerging at least a portion of the target surface in a treatment
bath, wherein the pressurized masking fluid passing through the
passageway prevents the treatment bath from entering the
passageway.
Inventors: |
Hunt; Mark Lawrence;
(Simpsonville, SC) ; DePalma; Michael Anthony;
(Simpsonville, SC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GENERAL ELECTRIC COMPANY |
Schenectady |
NY |
US |
|
|
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
50238169 |
Appl. No.: |
13/792620 |
Filed: |
March 11, 2013 |
Current U.S.
Class: |
216/41 ; 118/400;
134/166R; 134/22.18; 156/345.11; 204/242; 205/131; 427/282 |
Current CPC
Class: |
C25D 17/00 20130101;
B05D 3/042 20130101; C23C 18/1619 20130101; C23C 18/1605 20130101;
C25D 5/022 20130101; F01D 9/04 20130101; F01D 25/002 20130101 |
Class at
Publication: |
216/41 ; 427/282;
156/345.11; 118/400; 134/22.18; 134/166.R; 205/131; 204/242 |
International
Class: |
F01D 25/00 20060101
F01D025/00 |
Claims
1. A method of treating a target surface of an article including a
passageway, the method comprising: passing a pressurized masking
fluid through the passageway from a first side to a second side
including the target surface; and submerging at least a portion of
the target surface in a treatment bath while passing the
pressurized masking fluid through the passageway, wherein the
pressurized masking fluid passing through the passageway
substantially prevents the treatment bath from entering the
passageway.
2. The method of claim 1, further comprising: fluidly connecting
the pressure masker including pressurized masking fluid to the
first side of the passageway.
3. The method of claim 2, wherein the fluid connection includes a
multi-outlet manifold connection that connects to the first side
and comprises an internal passage, wherein the internal passage
receives the pressurized masking fluid and fluidly distributes it
to the passageway.
4. The method of claim 1, wherein the pressurized masking fluid
includes a gas.
5. The method of claim 1, wherein the passageway includes a cooling
hole.
6. The method of claim 1, wherein the pressurized masking fluid
includes a liquid.
7. The method of claim 1, wherein the treatment bath comprises a
stripping bath that strips at least a portion of the target surface
when a portion of the target surface is submerged.
8. The method of claim 7, wherein the stripping bath comprises an
acid stripping bath.
9. The method of claim 1, wherein the treatment bath comprises a
coating bath that coats at least a portion of the target surface
when a portion of the target surface is submerged.
10. The method of claim 10, wherein the coating bath comprises one
of a chemical bath or an electrolysis bath.
11. The method of claim 1, wherein the treatment bath comprises a
cleaning bath that cleans at least a portion of the target surface
when a portion of the target surface is submerged.
12. The method of claim 1, wherein the pressurized masking fluid
continues to pass through the passageway after the at least a
portion of the target surface is no longer submerged.
13. A pressurized masking system for treating a target surface of
an article including a passageway, the pressurized masking system
comprising: a pressure masker fluidly connected to a first side of
the passageway of the article for passing a pressurized masking
fluid through the passageway from the first side to a second side,
wherein the second side includes the target surface; and a
treatment bath comprising a treatment material to treat at least a
portion of the target surface, wherein the pressurized masking
fluid substantially prevents the treatment material from entering
the passageway.
14. The pressurized masking system of claim 13, wherein the
pressure masker includes a multi-outlet manifold connection
connecting to the first side of the article and an internal passage
receiving the pressurized masking fluid for fluidly distributing
the pressurized masking fluid to the passageway.
15. The pressurized masking system of claim 13, wherein the
pressurized masking fluid includes a gas.
16. The pressurized masking system of claim 13, wherein the
pressurized masking fluid includes a liquid.
17. The pressurized masking system of claim 13, wherein the
treatment bath includes a stripping bath that strips at least a
portion of the target surface when a portion of the target surface
is submerged in the treatment bath.
18. The pressurized masking system of claim 17, wherein the
stripping bath comprises an acid stripping bath.
19. The pressurized masking system of claim 13, wherein the
treatment bath comprises a coating bath that coats at least a
portion of the target surface when a portion of the target surface
is submerged.
20. The pressurized masking system of claim 19, wherein the coating
bath comprises one of a chemical bath or an electrolysis bath.
21. The pressurized masking system of claim 13, wherein the
treatment bath comprises a cleaning bath that cleans at least a
portion of the target surface when a portion of the target surface
is submerged.
Description
BACKGROUND OF THE INVENTION
[0001] The subject matter disclosed herein relates to masking
systems and, more specifically, to pressure masking systems for
treating articles with passageways.
[0002] In gas turbine engines, such as aircraft engines for
example, air is drawn into the front of the engine, compressed by a
shaft-mounted rotary-type compressor, and mixed with fuel. The
mixture is burned, and the hot exhaust gases are passed through a
turbine mounted on a shaft. The flow of gas turns the turbine,
which turns the shaft and drives the compressor and fan. The hot
exhaust gases flow from the back of the engine, driving it and the
aircraft forward.
[0003] During operation of gas turbine engines, the temperatures of
combustion gases may exceed approximately 1,649.degree. C.
(3,000.degree. F.), considerably higher than the melting
temperatures of the metal parts of the engine which are in contact
with these gases. Operation of these engines at gas temperatures
that are above the metal part melting temperatures is a
well-established art, and depends in part on supplying a cooling
air to the outer surfaces of the metal parts through various
methods. The metal parts of these engines that are particularly
subject to high temperatures, and thus require particular attention
with respect to cooling, are the metal parts forming combustors and
parts located aft of the combustor.
[0004] The metal temperatures can be maintained below melting
levels by using passageways such as cooling holes incorporated into
some engine components. Sometimes, thermal barrier coatings (TBCs)
may also be applied to the component by a thermal spray process.
However, the thermal spray process and other cleaning processes
(e.g., grit blasting, shot peening, water jet washing) often result
in overspray that partially or completely blocks the component's
cooling holes.
[0005] As a result, present thermal spray and cleaning processes
involve a multi-step, highly labor intensive process of applying a
partial layer of TBC, allowing the component and the TBC to
sufficiently cool to a temperature at which the component can
easily be handled, removing the component from an application
fixture on which the thermal spraying takes place, and removing any
masking, which is then followed by separately removing the
well-cooled, solidified coating from the cooling holes using a
water jet or other cleaning methods. To prevent the cooling holes
from becoming obstructed beyond a level from which they can be
satisfactorily cleaned, only a fraction of the desired TBC
thickness is applied prior to cleaning. As a result, the entire
process must typically be repeated several times until the desired
TBC thickness is reached. This complex process results in low
productivity, high cycle time, and increases costs by a factor of
five to ten times that of applying the same TBC to a similar
non-holed part. Even when coatings are not applied, the pressure
cleaning methods used to clean the target surfaces of articles can
similarly overflow and obstruct the article's cooling holes.
[0006] Further, in treating components with an acid stripping or
coating technique that involves submersing the component, masking
is increasingly important as passageways and cooling holes may be
fully submersed in an acid bath or coating. Previous techniques
have utilized wax plugs in order to mask the component. However,
these wax plugs can leak and must be removed after treating the
component, which may leave portions of wax behind or allow debris
to enter the passageways.
BRIEF DESCRIPTION OF THE INVENTION
[0007] In one embodiment, a method of pressure cleaning a target
surface of an article comprising one or more passageways is
disclosed. The method includes fluidly connecting a pressure masker
comprising pressurized masking fluid to a first side of at least
one passageway, passing the pressurized masking fluid through the
at least one passageway from the first side to a second side
comprising the target surface, and, cleaning the target surface
using a cleaning material, wherein the pressurized masking fluid
passing through the at least one passageway prevents the cleaning
material from permanently altering a cross sectional area of the at
least one passageway.
[0008] In another embodiment, a pressurized masking system for
cleaning a target surface of an article comprising passageways is
disclosed. The pressurized masking system includes a pressure
masker that fluidly connects to a first side of at least one
passageway of the article and passes a pressurized masking fluid
through the passageway from the first side to a second side,
wherein the second side comprises the target surface. The
pressurized masking system further includes a part cleaner that
projects a cleaning material towards the target surface, wherein
the pressurized masking fluid prevents the cleaning material from
permanently altering a cross sectional area of the at least one
passageway.
[0009] In another embodiment, a method of treating a target surface
of an article including a passageway is disclosed. The method
includes passing a pressurized masking fluid through the passageway
from a first side to a second side including the target surface;
and submerging at least a portion of the target surface in a
treatment bath while passing the pressurized masking fluid through
the passageway, wherein the pressurized masking fluid passing
through the passageway substantially prevents the treatment bath
from entering the passageway.
[0010] In another embodiment, a pressurized masking system for
treating a target surface of an article including a passageway is
disclosed. The pressurized masking system includes a pressure
masker fluidly connected to a first side of the passageway of the
article for passing a pressurized masking fluid through the
passageway from the first side to a second side, wherein the second
side includes the target surface. The pressurized masking system
further includes a treatment bath comprising a treatment material
to treat at least a portion of the target surface, wherein the
pressurized masking fluid substantially prevents the treatment
material from entering the passageway.
[0011] These and additional features provided by the embodiments
discussed herein will be more fully understood in view of the
following detailed description, in conjunction with the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The embodiments set forth in the drawings are illustrative
and exemplary in nature and not intended to limit the inventions
defined by the claims. The following detailed description of the
illustrative embodiments can be understood when read in conjunction
with the following drawings, where like structure is indicated with
like reference numerals and in which:
[0013] FIG. 1 is a schematic illustration of a pressure masking
system according to one or more embodiments shown or described
herein;
[0014] FIG. 2 is a top view of a pressure masking system according
to one or more embodiments shown or described herein;
[0015] FIG. 3 is a top view of another pressure masking system
according to one or more embodiments shown or described herein;
[0016] FIG. 4 is a flow diagram illustrating a method of pressure
cleaning an article using a pressure masking system according to
one or more embodiments shown or described herein;
[0017] FIG. 5 is a flow diagram illustrating a method of acid
stripping an article using a pressure masking system according to
one or more embodiments shown or described herein;
[0018] FIG. 6 is a flow diagram illustrating a method of coating an
article using a pressure masking system according to one or more
embodiments shown or described herein;
[0019] FIG. 7 is a schematic illustration of a pressure masking
system utilizing an acid bath according to one or more embodiments
shown or described herein; and
DETAILED DESCRIPTION OF THE INVENTION
[0020] One or more specific embodiments of the present invention
will be described below. In an effort to provide a concise
description of these embodiments, all features of an actual
implementation may not be described in the specification. It should
be appreciated that in the development of any such actual
implementation, as in any engineering or design project, numerous
implementation-specific decisions must be made to achieve the
developers' specific goals, such as compliance with system-related
and business-related constraints, which may vary from one
implementation to another. Moreover, it should be appreciated that
such a development effort might be complex and time consuming, but
would nevertheless be a routine undertaking of design, fabrication,
and manufacture for those of ordinary skill having the benefit of
this disclosure.
[0021] When introducing elements of various embodiments of the
present invention, the articles "a," "an," "the," and "said" are
intended to mean that there are one or more of the elements. The
terms "comprising," "including," and "having" are intended to be
inclusive and mean that there may be additional elements other than
the listed elements.
[0022] Pressurized masking systems disclosed herein generally
comprise a pressure masker and a part cleaner to treat the target
surface of an article including one or more passageways. In some
embodiments, treating may include cleaning the target surface.
While the part cleaner projects cleaning material towards the
target surface, pressurized masking fluid is fluidly connected to
the passageway via a pressure masker and passed therethrough to
prevent the permanent altering of a cross sectional area of the
passageway by the cleaning material. Pressurized masking systems,
and methods of pressure cleaning a target surface of an article
will be discussed in more detail herein.
[0023] Referring now to FIGS. 1-3, a pressurized masking system 100
is illustrated comprising a part cleaner 20 for projecting cleaning
material and a pressure masker 30 for fluidly connecting
pressurized masking fluid in order to clean an article 10. The
article 10 comprises one or more passageways 12 passing through the
article 10 from a first side 18 to a second side 19. As discussed
above, the article 10 can comprise a variety of different parts
such as a combustor liner or other component of a gas turbine
engine. In some embodiments, the article 10 can comprise a turbine
component such as a hot gas path component or a combustion
component. The passageways 12 can comprise any passage through the
article 10 (passing from the first side 18 to the second side 19)
that is intended to remain open (such that air can pass through)
when the article 10 is in use. For example, in some embodiments the
passageways 12 may comprise cooling holes.
[0024] As best illustrated in FIGS. 2-3, the second side 19 of the
article 10 comprises a target surface 11 that is to be cleaned. The
target surface 11 may be cleaned prior to first use, during routine
or repair maintenance, or as otherwise necessary depending on the
life of the article 10. As used herein, "cleaned" refers to
stripping, washing and/or treating the target surface such as
through grit blasting, shot peening, water jet washing or the like
as will become appreciated herein. For example, in some embodiments
the target surface 11 of the article 10 may comprise a coating 22
or other debris that is to be removed prior to applying a fresh
coating.
[0025] In some embodiments, such as when the article 10 comprises a
metal hot gas path component, the target surface 11 of the article
10 may have or will have a thermal barrier coating ("TBC") disposed
thereon. The TBC can comprise one or more layers of metal and/or
ceramic coating material applied to the target surface 11 of the
article 10 to impede the transfer of heat from hot combustion gases
to the article 10, thus insulating the component from the hot
combustion gas. The presence of the TBC on the surface permits the
combustion gas to be hotter than would otherwise be possible with
the particular material and fabrication process of the component.
Any suitable composition of TBC may be applied. For example, in
some embodiments the TBC can comprise a bond layer of MCrAlY,
wherein M is preferably Ni, Co, or a combination thereof, followed
by a layer of yttria stabilized zirconia (YSZ).
[0026] In some embodiments, the article 10 may be disposed on a
support stand 15 (FIG. 1) prior to or during the pressure cleaning
as will become appreciated herein. The support stand 15 may be
stationary or mobile (e.g., rotatable) and position the article 10
relative to the part cleaner 20 and the pressure masker 30 when
cleaning the target surface 11 of the article 10.
[0027] Still referring to FIGS. 1-3, the pressurized masking system
100 further comprises the part cleaner 20. The part cleaner 20
comprises any device that projects a cleaning material 25
(FIGS.2-3) towards the target surface 11 of the article 10. For
example, in some embodiments, the part cleaner 20 can comprise a
grit blaster. In such embodiments, the cleaning material 25 can
comprise pressurized air with aluminum oxide, walnut shells, dry
ice, charcoal, or any other particulates dispersed therein. In
other embodiments, the part cleaner 20 can comprise a shot peening
device. In such embodiments, the cleaning material 25 can comprise
pressurized air with metallic, glass or ceramic particles dispersed
therein. In even other embodiments, the part cleaner 20 may
comprise a pressure washer. In such embodiments, the cleaning
material 25 may comprise water with or without an additional
abrasive material.
[0028] The part cleaner 20 may be disposed at any position relative
to the article 10 that allows for the cleaning of the target
surface 11. For example, as illustrated in FIG. 1, in some
embodiments the article 10 may be disposed on a support stand 15
adjacent the part cleaner 20. The support stand 15 may then be able
to rotate or otherwise displace the article 10 with respect to the
part cleaner 20 and/or the part cleaner 20 may be able to
articulate with respect to the article 10. The part cleaner 20 may
then be used to project the cleaning material 25 towards the target
surface 11 of the article 10. However, as a result of cleaning
material 25 being projected toward the target surface 11 of the
article 10, some of the cleaning material 25 may enter one or more
of the passageways 12 from the second side 19 of the article 10. As
such, some of the cleaning material 25, and more particularly any
particulates (e.g., sand, shot, abrasives, etc.), may potentially
form obstructions 32 in the one or more passageways 12 if left
unopposed.
[0029] The part cleaner 20 may be used for a variety of
applications to clean the target surface 11 of the article 10. For
example in some embodiments the part cleaner 20 may be used to
remove dirt or other contaminants prior to applying a new coat. In
some embodiments, the part cleaner 20 may be used to remove a
previously applied coating that has since been worn and/or damaged.
For example, in some embodiments the part cleaner 20 may be used to
remove part or all of a TBC on the target surface 11 before
reapplying or rejuvenating the TBC. In some embodiments, the part
cleaner 20 may be used to remove one or more metallic coatings,
contamination layers (e.g., rust, dirt, oxidation, etc.), diffused
layers or other unwanted layers. While specific embodiments have
been presented herein, it should be appreciated that these are
illustrative only and any other application of the part cleaner 20
as part of the pressurized masking system 100 may also be
realized.
[0030] Referring still to FIGS. 1-3, the pressurized masking system
100 further comprises a pressure masker 30. The pressure masker 30
comprises a fluid connection 31 that fluidly connects a source of
masking fluid 35 to at least one passageway 12 of the article 10.
As used herein, "fluid connection" refers to a connection that
allows the pressurized masking fluid 35 to pass from the pressure
masker 30 to the passageway 12 with negligent loss to the outside
environment. The fluid connection can comprise, for example,
flexible tubes, hoses, pipes or any other conduit that directs the
passage of the pressurized masking fluid 35 to the one or more
passageways 12.
[0031] In one embodiment, such as that illustrated in FIG. 2, the
fluid connection 31 may comprise a tube that directly connects the
output of the pressure masker 30 to the first side 18 of the
passageway 12. In some embodiments, the fluid connection 31 may
comprise a single tube between the pressure masker 30 and a single
passageway 12 (such as that illustrated in FIG. 2). In other
embodiments, the fluid connection may comprise a single tube
leaving the pressure masker 30 that breaks off into segments that
connect to a plurality of passageways 12 (such as that illustrated
in FIG. 1). In even other embodiments, the fluid connection 31 may
comprise a plurality of tubes leaving the pressure masker 30 that
connects to a single or a plurality of passageways 12. For example,
the fluid connection 31 may comprise a plurality of channels of
similar or dissimilar pressurized masking fluids 35 that connect to
two or more passageways. Moreover, the plurality of channels may
comprise different pressures, temperatures, directions or mixtures
of pressurized masking fluids 35. It should be appreciated that any
other configuration that provides a fluid connection 31 between the
pressure masker 30 and one or more passageways 12 may alternatively
or additionally be realized.
[0032] For example, referring now to FIG. 3, in some embodiments
the fluid connection 31 may comprise a multi-outlet manifold
connection 40 comprising an internal passage 41 that can receive
pressurized masking fluid 35 from the pressure masker 30 and
fluidly distribute it to one or more passageways. The multi-outlet
manifold connection 40 can thereby attach directly to the first
side 18 of the article 10 and distribute the pressurized masking
fluid 35 to a wide area about the article 10. Any passageways 12
within that area will thereby have pressurized masking fluid 35
fluidly pass there through.
[0033] The pressurized masking fluid 35 can comprise any medium
that can pass through the passageway 12 with a positive energy and
prevent the permanent altering of a cross sectional area of the at
least one passageway by the cleaning material 25 (or particulates
thereof). As used herein, "prevent the permanent altering of a
cross sectional area" (and variants thereof) refers to removing
and/or preventing substantially all of the cleaning material 25
that may enter the passageway 12 so that the cross sectional area
of the passageway is not substantially reduced by a permanent
obstruction 32 or increased due to erosion, deformation or the
like. Examples of obstructions that would permanently alter the
cross sectional area of the passageway 12 include, for example,
large particulates lodged against a wall, a clumping of cleaning
material 25 or the like. The pressurized masking fluid 35 may
thereby comprise any material that can be forced through the one or
more passageways 12 at a masking pressure to impact on and remove
potential obstructions 32 from the cleaning material 25 that would
alter the cross sectional area.
[0034] For example, in some embodiments, the pressurized masking
fluid 35 may comprise a gas such as inert gas or nitrogen. Such
embodiments may be realized when the part cleaner 20 comprises a
grit blaster or shot peening device such that the gas can counter
any sand, peen or other cleaning particulate from the part cleaner
20 that enters the passageway 12 and remove it therefrom. In some
embodiments, the pressurized masking fluid 35 may comprise water
with or without abrasives distributed therein. Such embodiments may
be realized when the part cleaner 20 comprises a water jet or
similar device. While specific embodiments of pressurized masking
fluid and part cleaners have been presented herein, it should be
appreciated that additional and alternative pressurized masking
fluids and part cleaners may also be realized. Moreover, the
pressurized masking fluid 35 may comprise a masking pressure that
is greater than, equal to, or less than a cleaning pressure of the
cleaning material so long as the pressurized masking fluid 35 has
enough energy to remove obstructions 32 from the passageways 12. In
other embodiments, the masking pressure may comprise a negative
pressure (such as via a vacuum or suction element) on the second
side 19 of the article 10 such that the negative pressure pulls the
pressurized masking fluid 35 through the passageway 12. In some
embodiments, the masking pressure may comprise a variable pressure
that fluctuates during the masking process.
[0035] In operation, the pressure masker 30 thereby passes the
pressurized masking fluid 35 through the at least one passageway 12
at a masking pressure from the first side 18 to the second side 19
(wherein the second side 19 comprises the target surface 11 of the
article 10 that is to be cleaned). Likewise, the part cleaner 20
cleans the target surface 11 of the article 10 by projecting
cleaning material 25 towards the target surface. As a result of
flow pattern distributions, some of the cleaning material 25 may
enter one or more passageways 12 and form one or more obstructions
32. For example, the obstructions 32 may comprise a grouping of
particulates from the cleaning material that would decrease the
cross sectional area of the passageway 12 and reduce the amount of
air that could flow there through. However, to prevent the cleaning
material 25 from permanently obstructing the at least one
passageway 12 (and altering its cross sectional area), the
pressurized masking fluid 35 will contact the obstruction 32 and
push it back out of the passageway 12. In some embodiments, the
pressurized masking fluid 35 may prevent any obstructions 32 from
even entering the passageways 12 via the pressurized masking fluid
35 exiting the passageway 12 on the second side 19 of the article
10.
[0036] Referring now to FIGS. 1-4, a method 200 is illustrated for
pressure cleaning a target surface 11 of an article 10 comprising
one or more passageways 12. The method 200 first comprises fluidly
connecting the pressure masker 30 to a first side 18 of at least
one passageway 12 of the article 10 in step 210. As discussed
above, the fluid connection 31 may comprise a variety of
configurations and may connect any type of pressure masker 30 to
any number of passageways 12. The pressure masker 30 then passes
pressurized masking fluid 35 through the at least one passageway
from the first side 18 to the second side 19 in step 220. Likewise,
the part cleaner 20 cleans the target surface 11 on the second side
19 of the article 10 by projecting cleaning material 25 towards the
target surface 11 in step 230.
[0037] It should be appreciated that passing pressurized masking
fluid 35 through the at least one passageway 12 in step 220 and
cleaning the target surface 11 in step 230 may start and end
simultaneously in or with relative delay. For example, in some
embodiments the pressurized masking fluid 35 may be passing through
the passageway 12 in step 20 prior to the initiation of cleaning
the target surface 11 in step 230. Such embodiments may prevent a
buildup of obstructions 32 prior to activation of the pressure
masker 30. In some embodiments, the pressurized masking fluid 35
may continue to pass through the passageway 12 in step 220 after
the article 10 is cleaned in step 230. Such embodiments may help
ensure any obstacles 32 remaining in the passageways 12 after
cleaning is complete in step 230 are still removed by the
pressurized masking fluid 35.
[0038] It should now be appreciated that pressurized masking
systems may be used to clean the target surface of an article while
preventing the permanent altering of a cross sectional area of one
or more passageways. The use of a fluid connection between the
pressure masker and the one or more passageways can prevent the
need for physical masking barriers such as tape, wax or the like
potentially providing a more efficient cleaning system.
[0039] In a further embodiment, referring back to FIGS. 1-3 and 7,
the pressurized masking system 100 may further comprise an acid
stripping device 120 for treating target surface 11. In some
embodiments, treating target surface 11 may comprise acid stripping
target surface 11. Acid stripping device 120 comprises any device
that applies an acid 125 towards target surface 11 of article 10,
similar to part cleaner 20 of previous embodiments. This process is
referred to as acid stripping, i.e., the removal of a coating or a
material from target surface 11 of article 10 by applying an acid
to target surface 11. For example, in some embodiments, a coating
may have been added to target surface 11. In such embodiments, an
acid 125 may be used to remove a portion of the coating or all of
the coating on target surface 11. Further, pressurized masking
system 100 may further comprise a coating device 520 for treating
target surface 11. In some embodiments, treating target surface 11
may comprise applying a coating to, or coating, target surface 11.
Coating device 520 could be used to apply a coating 525 to surface
11 of article 10. Any known coatings relevant to the art may be
used, while any known coating techniques and the associated coating
devices may be utilized.
[0040] As illustrated in FIG. 7, in one embodiment, article 10 may
be fully or partially submersed in a treatment material within a
treatment bath 145. At least a portion of target surface 11 of
article 10 may be submersed in treatment bath 145. This can prevent
the treatment material of treatment bath 145 from entering the
passageway during the submersion. Treatment bath 145 can include a
stripping bath. Stripping baths may include acid stripping baths,
or stripping baths including solutions such as sodium hydroxide and
potassium hydroxide. This can be useful for stripping ceramic
coatings, such as coatings from Electron Beam Physical Vapor
Deposition (EBPVD). For instance, treatment material may include
acid 125 in an acid stripping bath 145 (FIG. 7), wherein article 11
may be partially or fully submersed in the treatment bath, while
fluidly connected to pressure masker 30. In any event, pressure
masker 30 prevents acid 125 from entering passageway(s) 12 of
article 10 during acid stripping via an acid bath. In a further
embodiment, pressure masker 30 can prevent any coating inside of
passageway(s) 12 from being removed during the acid stripping. In
yet another embodiment, treatment bath 145 may include, for
instance, a coating bath with a treatment material including a
coating 525. Such a coating bath can include a chemical bath or an
electrolysis bath. In one example, a coating bath may comprise a
bath of an aluminide coating. In using a coating bath, all or a
portion of article 10 may be submerged in the coating. This coating
could comprise the coating described above in reference to removing
a coating via an acid stripping technique. Similar to the other
embodiments, pressurized masking system 30 can prevent treatment
material, including coating 525, from entering passageway(s) 12.
Treatment bath 145 may also include a cleaning bath. Cleaning baths
can be used to clean target surface 11 after many processes. For
instance, cleaning bath may include a treatment material comprising
hot alkaline, pickling solution, or degreasing solutions.
[0041] Similar to the descriptions above, still referring still to
FIGS. 1-3, pressurized masking system 100 used for treatment bath
145, including acid stripping, coating, or cleaning techniques, may
further comprise a pressure masker 30. The pressure masker 30 may
comprise a source of masking fluid 35 and any known pump to pass
masking fluid 35. Pressure masker 30 may be used in conjunction
with a fluid connection 31 that fluidly connects masking fluid 35
to passageway(s) 12 of article 10. As used herein, "fluid
connection" refers to a connection that allows pressurized masking
fluid 35 to pass from pressure masker 30 to passageway(s) 12 with
negligent loss to the outside environment. Fluid connection 31 can
comprise, for example, flexible tubes, hoses, pipes or any other
conduit that directs the passage of the pressurized masking fluid
35 from pressure masker 30 to the passageway(s) 12.
[0042] In one embodiment, such as that illustrated in FIG. 2, fluid
connection 31 may comprise a tube that directly connects the output
of pressure masker 30 to first side 18 of passageway 12. In some
embodiments, fluid connection 31 may comprise a single tube between
pressure masker 30 and a single passageway 12 (such as that
illustrated in FIG. 2). In other embodiments, fluid connection 31
may comprise a single tube (manifold) leaving pressure masker 30
that breaks off into segments that connect to a plurality of
passageways 12 (such as that illustrated in FIG. 1). In even other
embodiments, fluid connection 31 may comprise a plurality of tubes
leaving pressure masker 30 that connects to a single or a plurality
of passageways 12. For example, fluid connection 31 may comprise a
plurality of fluid connections 31 of similar or dissimilar
pressurized masking fluids 35 that connect to two or more
passageways 12. Moreover, where a plurality of fluid connections 31
are used, they may employ different pressures, temperatures,
directions or mixtures of pressurized masking fluids 35. It should
be appreciated that any other configuration that provides a fluid
connection 31 between the pressure masker 30 and one or more
passageways 12 may alternatively or additionally be realized.
[0043] For example, referring now to FIG. 3, in some embodiments
fluid connection 31 may comprise a multi-outlet manifold connection
40 comprising an internal passage 41 that can receive pressurized
masking fluid 35 from pressure masker 30 and fluidly distribute it
to one or more passageways. Multi-outlet manifold connection 40 can
thereby attach directly to first side 18 of article 10 and
distribute pressurized masking fluid 35 to a wide area about
article 10. Any passageways 12 within that area will thereby have
pressurized masking fluid 35 fluidly pass therethrough.
[0044] Pressurized masking fluid 35 can comprise any medium that
can pass through passageway(s) 12 with a positive energy and
prevent the permanent altering of a cross sectional area of
passageway(s) 12 by acid 125 or coating 525 (or particulates
thereof) via treatment material of treatment bath 145. As used
herein, "prevent the permanent altering of a cross sectional area"
(and variants thereof) refers to removing and/or preventing
substantially all of treatment material of treatment bath 145, acid
125, or coating 525 that may enter passageway(s) 12 so that the
cross sectional area of the passageway 12 is not substantially
reduced by a permanent obstruction 32 or increased due to erosion,
deformation or the like. Examples of obstructions that would
permanently alter the cross sectional area of passageway(s) 12
include, for example, large particulates lodged against a wall, a
clumping of treatment material of treatment bath 145, acid 125, or
coating 525 or the like. Pressurized masking fluid 35 may thereby
comprise any material that can be forced through the passageway(s)
12 at a pressure to impact on and remove potential obstructions 32
from acid 125 or coating 525 that would alter the cross sectional
area.
[0045] For example, in some embodiments, pressurized masking fluid
35 may comprise a gas such as inert gas or nitrogen. Such
embodiments may be realized when acid stripping device 120 may
cause the stripped material to enter any passageway(s) 12, such
that the gas can counter any material removed by acid stripping
device 120 that may enter passageway(s) 12 and remove it therefrom.
Further embodiments may be realized when coating device 520 may
cause coating 525 to enter any passageway(s) 12, such that the gas
can counter any coating material applied by coating device 520 that
may enter passageway(s) 12 and remove it therefrom. In some
embodiments, pressurized masking fluid 35 may comprise water with
or without abrasives distributed therein. While specific
embodiments of pressurized masking fluid, part cleaners, acid
stripping devices, and coating devices, and treatment material of
treatment bath 145 have been presented herein, it should be
appreciated that additional and alternative pressurized masking
fluids and part cleaners, acid stripping devices, and coating
devices may also be realized. Moreover, pressurized masking fluid
35 may comprise a masking pressure that is greater than, equal to,
or less than a pressure of treatment material of treatment bath 145
or the applied acid 125 or coating 525 so long as pressurized
masking fluid 35 has enough energy to remove obstructions 32 from
passageway(s) 12. In other embodiments, the masking pressure may
comprise a negative pressure (such as via a vacuum or suction
element) on second side 19 of article 10 such that the negative
pressure pulls pressurized masking fluid 35 through passageway(s)
12. In some embodiments, the masking pressure may comprise a
variable pressure that fluctuates during the masking process.
[0046] In operation, pressure masker 30 thereby passes pressurized
masking fluid 35 through the passageway(s) 12 at a masking pressure
from first side 18 to second side 19 (wherein second side 19
comprises target surface 11 of article 10 that is to be cleaned).
Likewise, acid stripping device 120 or coating device 520 applies
acid 125 or coating 525 to target surface 11 of article 10 by
applying acid 125 or coating 525 towards target surface 11. As a
result of flow pattern distributions, some of the material removed
in the acid stripping process or some of coating 525 may enter
passageway(s) 12 and form one or more obstructions 32. For example,
obstructions 32 may comprise a grouping of removed material or
applied coating that would decrease the cross sectional area of
passageway 12 and reduce the amount of air that could flow
therethrough. However, to prevent acid 125 or coating 525 from
permanently obstructing the passageway 12 (and altering its cross
sectional area), pressurized masking fluid 35 will contact
obstruction 32 and push it back out of passageway 12. In some
embodiments, pressurized masking fluid 35 may prevent any
obstructions 32 from even entering passageway(s) 12 via pressurized
masking fluid 35 exiting passageway 12 on second side 19 of article
10.
[0047] Referring now to FIGS. 1-3 and 5, a method 300 is
illustrated for treating target surface 11 of article 10 including
passageway(s) 12. The method 300 may fluidly connect pressure
masker 30 to a first side 18 of passageway 12 of article 10 in step
310. As discussed above, fluid connection 31 may comprise a variety
of configurations and may connect any type of pressure masker 30 to
any number of passageways 12. Pressure masker 30 passes pressurized
masking fluid 35 through passageway 12 from first side 18 to second
side 19 in step 320. At least a portion of target surface 11 may
then be submerged in treatment bath 145, which may be used to strip
target surface 11 on second side 19 of article 10 by submersion in,
for instance, an acid bath in step 330.
[0048] It should be appreciated that passing pressurized masking
fluid 35 through passageway 12 in step 320 and acid stripping
target surface 11 in step 330 may start and end simultaneously in
or with relative delay. For example, in some embodiments
pressurized masking fluid 35 may be passing through passageway 12
in step 320 prior to the initiation of acid stripping target
surface 11 in step 330. Such embodiments may prevent a buildup of
obstructions 32 prior to activation of pressure masker 30. In some
embodiments, pressurized masking fluid 35 may continue to pass
through passageway 12 in step 320 after article 10 is acid stripped
in step 330. Such embodiments may help ensure any obstacles 32
remaining in passageway 12 after acid stripping is complete in step
330 are still removed by pressurized masking fluid 35.
[0049] Referring now to FIGS. 1-3 and 6, a method 400 is
illustrated for treating a target surface 11 of an article 10
comprising one or more passageways 12. The method 400 may include
fluidly connecting pressure masker 30 to a first side 18 of
passageway 12 of article 10 in step 410. As discussed above, fluid
connection 31 may comprise a variety of configurations and may
connect any type of pressure masker 30 to any number of passageways
12. Pressure masker 30 passes pressurized masking fluid 35 through
passageway 12 from first side 18 to second side 19 in step 420. At
least a portion of target surface 11 may then be submerged in
treatment bath 145, which may be used to coat target surface 11 on
second side 19 of article 10 by submersion in, for instance, a
chemical bath in step 430.
[0050] It should be appreciated that passing pressurized masking
fluid 35 through passageway 12 in step 420 and coating target
surface 11 in step 430 may start and end simultaneously in or with
relative delay. For example, in some embodiments pressurized
masking fluid 35 may be passing through passageway 12 in step 420
prior to the initiation of coating target surface 11 in step 430.
Such embodiments may prevent a buildup of obstructions 32 prior to
activation of pressure masker 30. In some embodiments, pressurized
masking fluid 35 may continue to pass through passageway 12 in step
420 after article 10 is coated in step 430. Such embodiments may
help ensure any obstacles 32 remaining in passageway(s) 12 after
coating is complete in step 430 are still removed by pressurized
masking fluid 35.
[0051] While the invention has been described in detail in
connection with only a limited number of embodiments, it should be
readily understood that the invention is not limited to such
disclosed embodiments. Rather, the invention can be modified to
incorporate any number of variations, alterations, substitutions or
equivalent arrangements not heretofore described, but which are
commensurate with the spirit and scope of the invention.
Additionally, while various embodiments of the invention have been
described, it is to be understood that aspects of the invention may
include only some of the described embodiments. Accordingly, the
invention is not to be seen as limited by the foregoing
description, but is only limited by the scope of the appended
claims.
* * * * *