U.S. patent application number 09/732231 was filed with the patent office on 2002-06-06 for system and method for reversing electrolyte flow during an electropolishing operation.
Invention is credited to Lorincz, Thomas A..
Application Number | 20020066675 09/732231 |
Document ID | / |
Family ID | 24942699 |
Filed Date | 2002-06-06 |
United States Patent
Application |
20020066675 |
Kind Code |
A1 |
Lorincz, Thomas A. |
June 6, 2002 |
SYSTEM AND METHOD FOR REVERSING ELECTROLYTE FLOW DURING AN
ELECTROPOLISHING OPERATION
Abstract
A pipe electrochemical polishing system (10, 10a) for in place
polishing of a pipe (28) has provision for detecting the instant
position of a cathode (14) within the pipe (28) such as cable marks
(52) and cable mark sensor (50), an infrared camera (60), heat
sensing crayon marks (64), thermisters (66), and capacitance
sensors (68), used individually or in combination. According to the
inventive in place electropolishing method (80) when it is
determined that the cathode is in a non horizontal portion (72) of
the pipe (28) and further is presently traveling generally
downward, then the direction of flow of the electrolyte (24) is
reversed to carry any bubbles in the electrolyte (24) away from the
area of the cathode (14).
Inventors: |
Lorincz, Thomas A.;
(Hollister, CA) |
Correspondence
Address: |
Larry E. Henneman Jr.
Henneman & Saunders
121 E. 11th Street
Tracy
CA
95376
US
|
Family ID: |
24942699 |
Appl. No.: |
09/732231 |
Filed: |
December 6, 2000 |
Current U.S.
Class: |
205/645 ;
204/225; 204/275.1; 205/672; 205/686; 234/69 |
Current CPC
Class: |
C25F 3/16 20130101; C25F
7/00 20130101 |
Class at
Publication: |
205/645 ;
204/275.1; 204/225; 205/672; 205/686; 234/69 |
International
Class: |
C25F 003/16; C25C
007/00 |
Claims
I claim:
1. An electropolishing apparatus for polishing the inner surface of
a pipe having both horizontal portions and non-horizontal portions,
the electropolishing apparatus comprising: an electrode; an
electrolyte source for providing electrolyte flow through the pipe;
a power supply for providing power to said electrical element; a
puller for pulling said electrical element through the pipe; and a
position detector for detecting the position of said electrical
element; and wherein the direction of flow of the electrolyte
through the pipe is reversible.
2. The electropolishing apparatus of claim 1, wherein the direction
of flow of the electrolyte in the pipe is reversible by the action
of operating a plurality of valves.
3. The electropolishing apparatus of claim 1, wherein the direction
of flow of the electrolyte in the pipe is reversible by the action
of reversing the direction of a reversible pump.
4. The electropolishing apparatus of claim 1, wherein said position
detector includes a detector for detecting how much of a cable has
been pulled through the pipe by the puller.
5. The electropolishing apparatus of claim 4, wherein said position
detector includes a plurality of marks on the cable and a mark
detector.
6. The electropolishing apparatus of claim 5, wherein the mark
detector is a optical mark detector.
7. The electropolishing apparatus of claim 5, wherein the mark
detector is a magnetic mark detector.
8. The electropolishing apparatus of claim 1, wherein said position
detector includes a heat detector for detecting heat created by
said electrical element.
9. The electropolishing apparatus of claim 8, wherein said position
detector includes a heat sensing crayon mark.
10. The electropolishing apparatus of claim 8, wherein said
position detector includes an infra red camera.
11. The electropolishing apparatus of claim 8, wherein said
position detector includes a thermister.
12. The electropolishing apparatus of claim 1, wherein said
position detector includes a capacitance measuring device for
measuring the capacitance in the pipe.
13. The electropolishing apparatus of claim 1, wherein said
electrode is a cathode.
14. The electropolishing apparatus of claim 1, wherein the
direction of flow of the electrolyte is reversed when the electrode
is traveling generally upward in the pipe.
15. The electropolishing apparatus of claim 1, further comprising a
controller responsive to position signals from said position
detector and operative to provide electrolyte flow direction
signals to said electrolyte source.
16. A method for polishing the inner surface of a pipe having both
generally horizontal sections and generally non-horizontal
sections, the method comprising: pulling an electrode through a
pipe filled with an electrolyte while providing electrical power to
said electrode; keeping track of the position of said electrode
within said pipe; flowing the electrolyte in a first direction in
the pipe when the electrode is traveling in a generally horizontal
section of the pipe; and flowing the electrolyte in a second
direction in the pipe when the electrode is traveling generally
upward in a generally non-horizontal section of the pipe
17. The method of claim 16, further comprising flowing the
electrolyte in said first direction in the pipe when the electrode
is traveling generally downward in a generally non-horizontal
section of the pipe.
18. The method of claim 16, wherein direction of flow of the
electrolyte is controlled by a plurality of valves
19. The method of claim 16, wherein direction of flow of the
electrolyte is controlled by a reversible pump.
20. The method of claim 16, wherein keeping track of the position
of said electrode is accomplished by measuring the progress of a
cable as the cable pulls said electrode through the pipe.
21. The method of claim 20, wherein measuring the progress of the
cable is accomplished by counting marks on the cable.
22. The method of claim 21, wherein the marks are visible
marks.
23. The method of claim 21, wherein the marks are detectable by a
magnetic sensor.
24. The method of claim 16, wherein keeping track of the position
of said electrode is accomplished by sensing heat from said
electrode.
25. The method of claim 24, wherein sensing heat from said
electrode is accomplished using an infra red camera.
26. The method of claim 24, wherein sensing heat from said
electrode is accomplished using a thermister.
27. The method of claim 24, wherein sensing heat from said
electrode is accomplished using a heat sensing crayon mark.
29. The method of claim 16, wherein keeping track of the position
of said electrode is accomplished by a capacitance sensor.
30. A computer readable medium having code embodied therein for
causing an electronic device to perform the steps of claim 16.
32. A computer readable medium having code embodied therein for
causing an electronic device to perform the steps of claim 17.
33. A computer readable medium having code embodied therein for
causing an electronic device to perform the steps of claim 20.
34. A computer readable medium having code embodied therein for
causing an electronic device to perform the steps of claim 24.
Description
TECHNICAL FIELD
[0001] The present invention relates to the field of
electrochemical processing, and more particularly to an apparatus
and method for improving electropolishing action by keeping gas
bubbles, which can interfere with such polishing, away from a
polishing electrode. The predominant current usage of the present
inventive apparatus and method for improved electropolishing is in
the in place polishing of pipes used in processing facilities.
BACKGROUND ART
[0002] It is known in the art to deposit and/or remove materials by
passing an electric current through a fluid electrolyte which is in
contact with a conductive electrode. Materials are exchanged
between the electrolyte and the electrode depending upon the
direction of current flow and the ionization of materials to be
deposited on or removed from the electrode. Electroplating is a
well known application of this general method. Electropolishing is
also well known in the art. In the electropolishing process,
irregularities and deposits on a surface are removed by causing
such to be drawn into the electrolyte solution.
[0003] An example is the in place electrochemical polishing of a
pipe. In such an example, a cathode is drawn through the pipe while
an electrolyte solution is simultaneously pumped through the pipe.
The pipe acts as an anode and is electrochemically polished in the
process. Since the electrolyte solution must be continuously pumped
through the pipe during the process, it is most practical to
recirculate the solution.
[0004] In the prior art it has been customary to circulate the
electrolyte solution through the pipe in a direction opposite to
that in which the cathode is drawn through the pipe. Although it
may not have been the primary intended advantage of this direction
of flow, at least an incidental advantage is that such an
arrangement tends to cause any bubbles formed at the cathode to be
carried back to that part of the pipe which has already been
polished. Such bubbles, when present in the area of the electrode,
tend to prevent the electrolyte from coming into direct contact
with the pipe and, therefore, interfere with the polishing process.
A dam adapted to facilitate the flow of such bubbles away from the
polishing area has been used successfully by the present inventor.
However, this solution has not been entirely successful where the
electrode is moving through generally vertical, or at least
non-horizontal, sections of the pipe, wherein the bubbles tend to
float upward toward the electrode.
[0005] It would be advantageous to have additional methods and/or
means for moving gas bubbles away from the electrode during an in
place pipe electropolishing operation. Such methods and/or means
would be useful by themselves and/or in combination with existing
methods and means.
SUMMARY
[0006] Accordingly, it is an object of the present invention to
provide an apparatus and method for improving the polishing action
of a pipe inner surface electropolishing system.
[0007] It is still another object of the present invention to
provide an apparatus and method for moving bubbles away from the
polishing area in a pipe electropolishing system.
[0008] It is yet another object of the present invention to provide
an apparatus and method for removing bubbles from the cathode area
in a pipe inner surface polishing system which can be used in
conjunction with existing methods and apparatus.
[0009] It is still another object of the present invention to
provide an apparatus and method for removing bubbles from the
cathode area in a pipe inner surface polishing system which can be
easily and inexpensively added to existing pipe electropolishing
devices.
[0010] Briefly, a known embodiment of the present invention is an
improved in place electropolishing apparatus for polishing the
inner surface of a pipe. According to one described embodiment of
the present invention, a cathode is drawn through a pipe while an
electrolyte solution is moved through the pipe in a direction
generally opposite to the direction of travel of the cathode.
However, when the cathode is moving generally upward through a
vertical or inclined portion of the pipe, the direction of flow of
the electrolyte is reversed such that the electrolyte also flows
upward in the pipe, thereby carrying bubbles, which would otherwise
tend to be trapped in the electropolishing area, away from the
cathode.
[0011] According to one embodiment of the present invention, it is
desirable to know where within a pipe the electrode is at any given
time during the processing process. This can be accomplished in a
number of ways, including but not limited to methods and means
specifically discussed herein. For example, the cable which pulls
the cathode through the pipe could be encoded (e.g., with colored
or magnetic markings, or the like) such that the position of the
cathode can be generally determined by keeping track of how much
cable has been pulled through. Another means would be to measure
the resistance and/or capacitance between the cathode and a
measuring electrode placed at the end of the pipe and/or at various
points along the pipe. Other means for detecting the position of
the cathode could rely upon the fact that there is a significant
amount of heat generated at the location of the cathode during the
electropolishing process. This heat can be detected by an infrared
camera, by thermisters placed at specified locations along the
pipe, or by marking the pipe at various locations and/or intervals
with a heat sensitive crayon that changes color or melts when
heated by the cathode.
[0012] An advantage of the present invention is that polishing is
improved in at least some non-vertical sections of a pipe.
[0013] Another advantage of the present invention is that gas
bubbles are removed away from the area of the cathode in an in
place pipe polishing system.
[0014] A further advantage of the invention is that it can be used
in conjunction with known methods and/or apparatus for moving the
bubbles away from the electrode in an in place pipe
electropolishing system.
[0015] Still another advantage of the invention is that existing in
place pipe electropolishing devices can be easily and inexpensively
modified to incorporate the inventive method and apparatus.
[0016] These and other objects and advantages of the present
invention will become clear to those skilled in the art in view of
the description of modes of carrying out the invention, and the
industrial applicability thereof, as described herein and as
illustrated in the several figures of the drawing. The objects and
advantages listed are not an exhaustive list of all possible
objects or advantages of the invention. Moreover, it will be
possible to practice the invention even where one or more of the
intended objects and/or advantages might be absent or not required
in the application.
[0017] Further, those skilled in the art will recognize that
various embodiments of the present invention may achieve one or
more, but not necessarily all, of the above described objects and
advantages. Accordingly, the listed objects and/or advantages are
not considered to be essential elements of the present invention,
and should not be construed as limitations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is block diagrammatic view of a particular embodiment
of an in place pipe electropolishing system according to the
present invention;
[0019] FIG. 2 is a more detailed view of a portion of the cable and
cable mark detector of FIG. 1;
[0020] FIG. 3 is a block diagrammatic view of another particular
embodiment of an in place pipe electropolishing system according to
the present invention; and
[0021] FIG. 4 is a flow chart summarizing one particular method for
electropolishing the inner surface of a pipe according to the
present invention.
DETAILED DESCRIPTION
[0022] The embodiments and variations of the invention described
herein, and/or shown in the drawings, are presented by way of
example only and are not limiting as to the scope of the invention.
Unless otherwise specifically stated, individual aspects and
components of the invention may be omitted or modified, or may have
substituted therefore known equivalents, or as yet unknown
substitutes such as may be developed in the future or such as may
be found to be acceptable substitutes in the future. The invention
may also be modified for a variety of applications while remaining
within the spirit and scope of the claimed invention, since the
range of potential applications is great, and since it is intended
that the present invention be adaptable to many such
variations.
[0023] Unless otherwise stated herein, component parts of the
invention will be familiar to one skilled in the art, and may be
purchased or readily manufactured accordingly. Also, unless
otherwise stated herein, substitutions can be made for the
components described, and each of the individual components, except
as specifically claimed, is not an essential element of the
invention.
[0024] A known mode for carrying out the invention is an in place
pipe electrochemical polishing system 10. The in place pipe
electrochemical polishing system 10 is depicted in a block
schematic diagrammatic view in FIG. 1. As one skilled in the art
will recognize, some of the relevant component parts of the in
place pipe electrochemical polishing system are a cathode 14, a
cathode puller cable 16, a cable puller 18, a valve 20, an
electrolyte reservoir 22 for containing a supply of an electrolyte
24, and an electrolyte pump 26, all of which are provided for the
purpose of polishing the inner surface of a pipe 28. One end of
pipe 28 is coupled to system 10 by an adapter 25, and the other end
of pipe 28 is coupled to an end pipe 29 of system 10 by another
adapter 27. In the electrochemical polishing process, the cathode
14 is drawn toward the cable puller 18 by the cathode puller cable
16, while electrical current is supplied, via cable 16, to cathode
14 from a power supply 30. The current flows through the
electrolyte 24 in the pipe 28, which shares a common ground with
the power supply 30 such that the pipe 28 acts as an anode and the
inner surface thereof is polished, according to the known
principles of electropolishing. During the process, the electrolyte
24 is generally pumped to flow through the pipe 28 in a direction
opposite that in which the cathode 14 is being drawn, as indicated
by directional arrow 32. The valve 20 prevents the electrolyte 24
from escaping the pipe 28 while allowing the cathode puller cable
16 to be pulled therethrough.
[0025] In the particular example of the in place polishing system
10 shown in the view of FIG. 1, two filters 34 are placed in the
path of the electrolyte to insure that particulate matter removed
from the inside of the pipe 28 is removed from the electrolyte 24
solution as it is recirculated through the in place polishing
system 10 by the electrolyte pump 26. An electric heater 36 and a
temperature indicating control 38 are also provided in the path of
the electrolyte 24. In this example, the electric heater 36 and the
temperature indicating control 38 are located in the electrolyte
reservoir 22. Also, in the present example of the invention, a
collector sump 40 catches the electrolyte 24 as it flows out of end
pipe 29. A collector sump pump 42 disposed in sump 40 pumps the
electrolyte 24 from the collector sump 40 to the electrolyte
reservoir 22, via a return line 43. A heat exchanger 44 is provided
in the path of the electrolyte 24 with a chiller 46 operatively
connected thereto. The chiller 46 is a conventional refrigeration
unit and pump, and the heat exchanger 44 is adapted to transfer
heat from the electrolyte 24 in end pipe 29 to the chiller 46.
[0026] In the embodiment of the invention shown in FIG. 1, the pump
26 is a reversible pump. One skilled in the art will recognize that
in order for pump 26 to be able to reverse the flow of electrolyte
24 through pipe 28, collector sump 40 and reservoir 22 must be
sealed. Further, sump pump 42 must be set to maintain the level of
electrolyte 24 in sump 40 above the open end 45 of end pipe 29, to
avoid introducing air into end pipe 29 when flow is reversed.
Additionally, sump pump 42 must allow the reverse flow of
electrolyte 24 from return line 43 back into sump 40. Other related
modifications might optionally be made according to the particular
application, as will be discussed in more detail hereinafter.
[0027] Further, in the embodiment of the invention shown in the
view of FIG. 1, the cathode puller cable 16 is marked such that a
cable mark sensor 50 can sense how far the cable has been pulled
and generate a corresponding position signal. A controller 100
receives the position signal from sensor 50 via a signal line 102,
and provides a flow direction signal, via signal line 104, to pump
26 depending on the position of cathode 14. Additionally, the
contour of pipe 28 is provided to controller 100 by a system
operator (not shown). When controller 100 determines from the
position signal and the contour of pipe 28 that cathode 14 is
traveling downward through a first non-horizontal portion 72a of
pipe 28, controller asserts a first flow direction signal on signal
line 104 that causes pump 26 to maintain the flow of electrolyte 24
in the normal direction indicated by directional arrow 32.
Similarly, when controller 100 determines that cathode 14 is in a
horizontal portion 70 of pipe 28, controller 100 asserts the first
flow direction signal on signal line 104, causing pump 26 to
maintain the flow of electrolyte 24 in the normal direction.
However, when controller 100 determines that cathode 14 is
traveling upward through a second non-horizontal portion 72b of
pipe 28, controller 100 asserts a second flow direction signal on
signal line 104, causing pump 26 to reverse the flow of electrolyte
24 through pipe 28, such that electrolyte 24 flows in the direction
opposite to directional arrow 32.
[0028] Those skilled in the art will recognize, that the
above-described function of controller 100 may be performed
manually, but perhaps not as efficiently, by a system operator.
Therefore, an automated controller such as controller 100 is not
considered to be an essential element of the present invention.
[0029] FIG. 2 is a more detailed view of the cable mark sensor 50
and a portion of the cable 16 showing a plurality of cable marks 52
on the cable. In the embodiment shown in the view of FIG. 2, the
cable mark sensor 50 is a optical sensor and the cable marks 52 are
relatively (as compared to the color of the cable 16) dark bands
about the cable 16. However, it is within the scope of the sensor
that essentially any means, known or yet to be developed, could be
used to sense how much of the cable has been pulled past the cable
mark sensor 50. For example, the cable marks 52 could be magnetic
bands and the cable mark sensor 50 could be a magnetic sensor.
Optionally, cable mark sensor 50 could be replaced by, for example,
measuring the amount of cable drawn through system 10 by monitoring
the revolutions of cable puller 18.
[0030] FIG. 3 is an alternative in place polishing system 10a, in
which components are alike to and numbered the same as those of the
example of FIG. 1, except for those specifically discussed herein
as being different. In the alternative in place polishing system
10a, a standard cable 16a is a plain, unmarked cable, such as has
been used in the prior art, and the pump 26a is a conventional
unidirectional pump, such as has been used in the prior art.
[0031] Visible in the view of FIG. 3 are an infra red camera 60, a
heat sensing crayon 62 and a plurality (two are shown) of heat
sensing crayon marks 64 on the pipe 28. A plurality (two are shown)
of thermisters 66 are also shown placed on the pipe 28 in the view
of FIG. 3. A plurality (two are shown) of capacitance sensors are
also shown on the pipe 28 in the view of FIG. 3.
[0032] As was briefly discussed hereinbefore, the practice of the
present invention requires some knowledge of the present location
of the cathode 14 during the polishing process. Since the cathode
14 gives off a substantial amount of heat during the
electropolishing process, the infra red camera 60 can be used to
detect the instant location of the cathode 14. Similarly, the heat
sensing marks 64 made by the heat sensing crayon 62 will change
color when the cathode 14 is passing within the pipe 18 under the
marks 64, thereby disclosing the location of the cathode 14. In
like manner, the thermisters 66 will detect a rise in heat when the
cathode 14 is passing within the pipe 28 at the location of the
thermisters 66. Also, when the cathode 14 passes through a
particular location in the pipe 28, the capacitance across the pipe
will be reduced, and this can be detected by one of the capacitance
sensors 68 placed at such location.
[0033] It should be noted that, in actual practice, more than two
cathode position sensors (e.g., thermisters 66, capacitance sensors
68, heat sensing crayon marks 64, or the like) will be used,
depending on the configuration of pipe 28. In particular, position
sensors would be placed along pipe 28 at each point where cathode
14 begins or completes an upward traverse of an non-horizontal
portion of pipe 28. These points correspond to cathode positions
where it may be desirable to change the direction of electrolyte 24
flow through pipe 28.
[0034] Also seen in the view of FIG. 3 are a first valve 74, a
second valve 76, a third valve 78, a fourth valve 80, a first
crossover pipe 82 and a second crossover pipe 84. The four valves
74, 76, 78 and 80 are each diversion valves which selectively route
a single input to either one of two outputs. As previously
discussed herein, in normal operation the pump 26a pumps the
electrolyte 24 through the pipe 28 in the direction indicated by
the directional arrow 32, and also as indicated by directional
arrows 32a, 32b, 32c and 32d in the view of FIG. 3. In such an
operational mode, the valves 74, 76 78 and 80 are all positioned
such that the flow of the electrolyte 24 through the pipe 28 is
essentially the same as in the prior art, as illustrated in the
view of FIG. 1. In this mode there is no flow of electrolyte
through either of the cross over pipes 82 and 84.
[0035] In order to reverse the direction of flow of the electrolyte
24 through the pipe 28, the valves 74, 76, 78 and 80 are all
switched over such that the electrolyte 24 flows through the first
crossover pipe 82 in a direction indicated by a directional arrow
86a, and further such that the electrolyte 24 flows through the
second crossover pipe 84 in a direction indicated by a directional
arrow 86b. This results in the flow of electrolyte within the pipe
28 being in a direction indicated by a directional arrow 86.
[0036] In operation, when the cathode 14 is pulled through a
horizontal portion 70 of the pipe, the flow of electrolyte 24 will
be in the direction indicated by the directional arrow 32 which, as
discussed above, is opposite to the direction of travel of the
cathode 14. Similarly, when the cathode 14 is traveling generally
downward, through a non-horizontal portion 72a in the example of
FIG. 3, then the flow of electrolyte 24 will also be in the
direction indicated by the directional arrow 32. However, when the
cathode 14 is traveling generally upward, as it would be through
non-horizontal portion 72b of FIG. 3, then the direction of the
flow of the electrolyte 24 will be reversed, as indicated by the
directional arrow 86. This direction of flow will carry any bubbles
in the electrolyte 24 away from the cathode 14. Such bubbles would
otherwise try to move upward and would be trapped in the area of
the cathode 14. This would prevent the electrolyte 24 from making
good contact on the pipe 28, and would adversely effect the
polishing action in such section of the pipe 28.
[0037] Regarding the several means available for detecting the
position of the electrode 14 in the pipe 28: If used, the infrared
camera 60 could be moved, as necessary during the course of the
polishing process, such that those portions of the pipe 28 wherein
the cathode 14 is currently located could be seen by the infra red
camera 60. It should be noted that the practice of the present
inventive method is not limited to the use of any one method for
detecting the position of the cathode 14. Any of the thermisters
66, capacitance sensors 68, heat sensing crayon marks 64, or
infrared camera 60, or any combination thereof could be used to
detect the current position of the cathode 14 during a single
electropolishing process. Also, any of these could be used in
combination with the cable marks 52 and cable mark sensor 50,
previously discussed herein in relation to FIGS. 1 and 2, or could
be substituted for or used in combination with other methods and/or
means for detecting the present position of the cathode 14.
[0038] Controller 100 is not shown in FIG. 3, so as not to
unnecessarily obscure the other features of system 10a. Those
skilled in the art will understand, however, that system 10a may be
implemented automatically with controller 100, or manually by an
operator (also not shown). In fact, certain of the disclosed
position sensors (e.g., infra red camera 60 crayon marks 60) are
well suited for use with a manual system. The other disclosed
position sensors (e.g., thermisters 66 and capacitative sensors 68)
generate electrical signals that can be interpreted by controller
100, and are therefore well suited for an automatic system. In such
an automated system, controller 100 receives position signals from
the sensors via signal lines (not shown), and, responsive to the
position signals, controls valves 74, 76, 78, and 80 via control
lines (not shown).
[0039] FIG. 4 is a flow chart summarizing one particular in place
electropolishing method 90, according to the present invention. In
a begin polish operation 92 voltage is applied to the cathode 14 by
the power supply 30 (FIGS. 1 and 3), and the cable puller 18 (FIG.
1) or cable puller 18a (FIG. 3) begins to pull the cathode 14
through the pipe 28 by the cathode puller cable 16 (FIG. 1) or 16a
(FIG. 3). The begin polish operation 92 is conventional in nature
and is not unlike such operation as applied in the prior art.
[0040] One skilled in the art will recognize in the diagram of FIG.
4 that a detect cathode position operation 94 begins an operational
loop that is repeated during the continuation of the in place
electropolishing method 90. In a detect cathode position operation
94, the position of the cathode 14 (FIGS. 1 and 3) is detected,
such as by use of the calibrated cathode puller cable 16 having
thereon cable marks 52 and the cable marks sensor as discussed in
relation to FIG. 1. Alternatively, any other method, such as the
heat detecting methods using the infra red camera 60 (FIG. 3), the
heat sensing crayon marks 64, the thermisters, or the like and/or
any combination thereof could be used. Another alternative for
accomplishing the detect cathode position operation 84 could be the
use of the capacitance sensors 68 as discussed previously herein in
relation to FIG. 3, or essentially any other means for detecting
the position of the cathode 14, now known or yet to be
developed.
[0041] Next, in an in horizontal portion decision operation 96 it
is determined if the cathode 14 is in a generally horizontal
portion 70 of the pipe 28. If the cathode 14 is in a horizontal
portion of the pipe 28, then the in place electropolishing method
90 proceeds to a normal electrolyte flow operation 98 wherein the
electrolyte 24 (FIGS. 1 and 3) is started or allowed to continue to
flow in the "normal" direction as indicated by the directional
arrow 32. If it is determined in the in horizontal portion decision
operation 96 that the cathode 14 is not in a horizontal portion 70
of the pipe, then operation of the in place electropolishing method
90 proceeds to a traveling upward decision operation 100 wherein it
is determined if the cathode 14 is presently traveling in a
generally upward direction. If the cathode 14 is not traveling in a
generally upward direction, then the in place electropolishing
method 90 proceeds to the normal electrolyte flow operation 98
wherein the electrolyte 24 (FIGS. 1 and 3) is started or allowed to
continue to flow in the "normal" direction as indicated by the
directional arrow 32. If it is determined in traveling upward
decision operation 100 that the electrode 14 is presently traveling
in a generally upward direction, then method 90 proceeds to a
reverse electrolyte flow operation 101.
[0042] In the reverse electrolyte flow operation 101, flow of the
electrolyte 24 (FIGS. 1 and 3) is reversed to flow in the direction
indicated by directional arrow 86 in FIG. 3. This can be
accomplished, as discussed previously herein in relation to FIG. 3,
by switching the valves 74, 76, 78 and 80 such that the electrolyte
24 flows through the crossover pipes 82 and 84 of FIG. 3.
Alternatively, the pump 26 of FIG. 1 could be reversed to reverse
the direction of flow of the electrolyte. Still other alternatives,
known or yet to be developed, could be used to reverse the
direction of flow of the electrolyte 14 to accomplish the present
inventive method.
[0043] Following either the normal electrolyte flow operation 98 or
the reverse electrolyte flow operation 101, in an end of pipe
decision operation 102 it is determined if the cathode 14 has
reached the end of the pipe 28. If the cathode 14 has reached the
end of the pipe 28, the in place electropolishing method 90
proceeds to an end polish operation 104 wherein the pipe
electrochemical polishing system 10, 10a is cleaned and shut down
according to prior art methods. If it is determined in the end of
pipe decision operation 102 that the end of the pipe 28 has not
been reached then the decision loop returns to the detect cathode
position operation 94 and the process is repeated as indicated in
the flow diagram of FIG. 4.
[0044] Various modifications to the inventive method and apparatus
are also quite possible, while remaining within the scope of the
invention. For example, alternative means could be developed for
determining the position of the cathode 14. Also, alternative means
for reversing the flow of the electrolyte 24 in the pipe 28 could
be developed. Another logical alternative would be to use the
apparatus specifically disclosed herein, and/or other apparatus yet
to be developed, in combinations not specifically discussed
herein.
[0045] All of the above are only some of the examples of available
embodiments of the present invention. Those skilled in the art will
readily observe that numerous other modifications and alterations
may be made without departing from the spirit and scope of the
invention. Accordingly, the disclosure herein is not intended as
limiting and the appended claims are to be interpreted as
encompassing the entire scope of the invention.
INDUSTRIAL APPLICABILITY
[0046] The inventive pipe electrochemical polishing system 10, 10a
and associated in place electropolishing method 80 are intended to
be widely used for the in place polishing of the inner surfaces of
piping systems. It is presently thought by the inventor that it
will be useful to reverse the direction of flow of the electrolyte
14 in any section of the pipe 28 that is more than just 2 or 3
degrees off of horizontal, and further wherein the cathode 14 is
traveling generally downward in such section.
[0047] Since the inventive pipe electrochemical polishing system
10, 10a and associated in place electropolishing method 90 may be
readily produced and integrated with existing electropolishing
systems, and since the advantages as described herein are provided,
it is expected that it will be readily accepted in the industry.
For these and other reasons, it is expected that the utility and
industrial applicability of the invention will be both significant
in scope and long-lasting in duration.
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