TOOLING FOR REMOVING SAND FROM A TURBINE ENGINE
The present invention relates to tooling for
removing sand from a turbine engine, such as an airplane
turbojet .
5 When operating in certain geographical zones, a
turbine engine absorbs a certain quantity of sand, which
is mixed with residues generated by imperfect combustion
of kerosene in the combustion chamber. This mixture can
then become stuck to the inside walls of the turbine
10 engine, downstream from the combustion chamber. The
layer as formed in this way on said walls is constituted
both by fine particles of sand and by a compacted
agglomeration of polluted sand. The presence of this
layer makes it difficult, if not impossible, to perform
15 visual inspection of certain portions of the turbine
engine during maintenance operations, in particular
concerning the low pressure and high pressure turbines.
There is also a risk of such particles degrading certain
bearings in the turbine engine.
20 Access to the inside space of a turbine engine is
restricted and makes it difficult to clean the walls in
question, thus making it necessary to perform lengthy and
expensive disassembly of the various portions of the
turbine engine in order to be able to clean them.
25 Another solution consists in protecting certain
portions of the turbine engine, such as bearings, and
then in blowing compressed air into the enclosure of the
turbine engine in order to detach the particles from the
inside walls that are to be cleaned. That cleaning
30 .method is relatively inaccurate and can pollute other
'. portions of the turbine engine while the air is being
blown.
A particular object of the invention is to provide a
solution to this problem that is simple, effective, and
35 inexpensive.
To this end, the invention provides tooling for
removing sand from a turbine engine, such as an airplane
turbojet, the tooling comprising at least one endoscopic
display device comprising display means and a duct having
light guide and image transmission means mounted therein,
a suction device having suction means connected to a
5 suction duct fastened to the duct of an above-mentioned
display device, and a plasma jet generator device
comprising a plasma torch connected to gas supply and
electricity power supply means suitable for operating
said plasma torch, said plasma torch being fastened to
10 the duct of an above-mentioned display device.
In this way, it is easy to introduce the plasma
torch fastened to the duct of the display device into an
inside zone of the turbine engine in order to detach the
layer of particles from a surface that is to be cleaned.
15 The duct of the suction device then enables the detached
particles to be sucked up. On each occasion, the display
device makes it possible to ensure that the plasma torch
of the suction duct is properly positioned, thereby
facilitating the operation. The fact that the plasma
20 torch and the suction duct are fastened to a duct of a
display device makes handling of the tooling easy and
thus facilitates cleaning by an operator.
In a first embodiment of the invention, the tooling
comprises a first set of tooling constituted by a first
25 display device coupled to a plasma jet generator device,
and a second set of tooling constituted by a second
display device coupled to a suction device.
In a second embodiment of the invention, the suction
device and the plasma jet generator device are coupled to
3 0 a single display device soas to -form a single set of
tooling.
Advantageously, the plasma torch is a cold plasma
: torch. This serves to avoid heating -and damaging the
walls that are to be cleaned of the turbine engine.
35 The invention also provides a method of removing
sand from a turbine engine with the help of tooling of
the first embodiment, the method being characterized in
that it comprises the steps consisting in:
inserting both the plasma torch and the duct of
the first display means simultaneously in the turbine
engine in such a manner that the torch and the free end
of said duct are situated facing a surface to be cleaned;
using the plasma torch to detach a layer of
particles, e.g. such as a layer of sand, from the surface
to be cleaned;
inserting both the suction duct and the duct of
the second display means simultaneously into the turbine
engine in such a manner that the ends of said ducts are
situated facing the surface to be cleaned; and
using the suction duct to suck up the previously
detached particles.
Finally, the invention provides a method of removing
sand from a turbine engine with the help of tooling of
the second embodiment, the method being characterized in
that it comprises the steps consisting in:
inserting the plasma torch, the duct of the
suction means, and the duct of the display means
simultaneously into the turbine engine in such a manner
that the torch and the free ends of said ducts are
situated facing a surface to be cleaned;
using the plasma torch to detach a layer of
particles, e.g. such as a layer of sand, from the surface
to be cleaned; and
using the suction duct to suck up the previously
detached particles.
The invention can be better understood and other
details, characteristics, and advantages of the invention
appear on reading the following description made by way
of non-limiting example and with reference to the
accompanying drawings, in which:
Figure 1 is a diagrammatic view showing the use of
a first set of tooling in a first embodiment of the
invention;
Figure 2 is a diagrammatic view showing the use of
a second set of tooling in the first embodiment of the
invention; and
Figure 3 is a diagrammatic view showing the use of
5 tooling in a second embodiment of the invention.
Figures 1 and 2 show a method of removing sand from
an internal portion of a turbojet module 1, which method
is performed during a maintenance operation with the help
of tooling in a first embodiment of the invention. By
10 way of example, the module 1 is coilstituted by a portion
of the high pressure turbine. This module 1 has been
disassembled from the remainder of the turbojet during
the maintenance operation.
As mentioned above, such removal of sand seeks to
15 remove the layer of particles that are attached or stuck
to the inside walls of the module 1, and that are
difficult for an operator to access. In particular, it
is necessary to be able to have access to the cavities 2
situated between the turbine disks and/or to other
20 cavities 3 of the module 1. If such cleaning is
effective, it becomes possible to proceed with visual
inspection of the various portions of the module 1,
without any need to disassemble it into submodules.
To this end, the tooling comprises a first set of
25 tooling 4 made up of a first endoscopic display device 5'
coupled to a plasma jet generator device 6, and a second
set 7 of tooling formed by a second endoscopic display
device 8 coupled to a suction device 9.
Each display device 5, 8 has display means 9, e.g.
30 comprising a screen 10, and a duct 11 in which light
guide and image transmission means are mounted. Thus,
the image of an internal portion or wall of the module 1
situated facing the free end 12 of the duct 11 can be
displayed on the screen 10 in order to be visible for an
35 operator on the outside. The duct 11 is flexible, while
nevertheless having a degree of stiffness, so as to be
easlly inserted in the module 1.
The plasma jet generator device 6 comprises a cold
plasma torch connected to gas supply and electrical power
means 13 suitable for operating said plasma torch via
corresponding supply lines 14. By way of example, these
5 lines may be mounted in a sheath surrounding both the
duct 11 of the first display device 5 and said lines 14.
The torch is fastened to the duct 11 of the first display
device 5.
A cold plasma torch is known in particular from
10 Document US 2011/0220143.
The suction device 9 comprises suction means 15
connected to a suction duct 16 fastened to the duct 11 of
the second display device 8. The two ducts 11 and 16 may
be surrounded by a common sheath.
15 In order to clean the walls of the internal cavities
2 and 3 of the module 1, the operator begins by inserting
both the plasma torch and the ducts 11 of the first
display means 5 simultaneously into the turbine engine in
such a manner that the torch and the free end 12 of the
20 duct 11 are situated facing a surface that is to be
cleaned.
The operator then detaches the layer of particles
present on the above-mentioned surface with the help of
the plasma torch, and then extracts the plasma torch and
25 the ducts 11 from the module 1.
Thereafter, the operator inserts both the suction
ducts 16 and the ducts 11 of the second display means 8
simultaneously into the module 1 in such a manner that
the free ends 12 and 17 of said ducts 11 and 16 are
30 sltuated facing said surface, and then proceeds to suck
up the previously detached particles using the suction
duct 16. Finally, the operator extracts the ducts 11 and
16 from the module 1.
it can be seen that the tooling of the invention
35 enables the layer of particles to be removed quickly and
easily, without requiring the module 1 to be
disassembled. Furthermore, such cleaning does not
require protection to be applied to certain portions of
the module 1, such as bearings. Finally, the cleaning
does not run any risk of polluting other portions of the
module 1 or of the turbojet.
5 Figure 3 shows tooling in a second embodiment in
which the suction device 9 and the plasma jet generator
device 6 are coupled to a single endoscopic display
device 5 so as to form a single set of tooling.
Under such circumstances, the torch is fastened to
10 the duct 11 of the display device 5 and/or to the suction
duct 16. These ducts 11 and 16 and the supply lines 14
for the plasma torch may be surrounded by a common
sheath.
Under such circumstances, the method of removing
15 sand is simpler since it consists in:
inserting the plasma torch, the duct 16 of the
suction device 9, and the duct 11 of the display means 5
simultaneously into the module 1 so that the plasma torch
and the free ends 12 and 17 of said ducts 11 and 16 are
20 situated facing a surface to be cleaned;
detaching the layer of particles from said surface
with the help of the plasma torch;
sucking up the previously detached particles with
the help of the suction duct 16; and
25 simultaneously removing the plasma torch, the duct
16 of the suction device 9, and the duct 11 of the
display device 5 from the module 1.
CLAIMS
1. Tooling for removing sand from a turbine engine, such
as an airplane turbojet, the tooling comprising at least
one endoscopic display device (5, 8) comprising display
means (9) and a duct (11) having light guide and image
transmission means mounted therein, a suction device (9)
having suction means (15) connected to a suction duct
(16) fastened to the duct (11) of an above-mentioned
display device (5, 8), and a plasma jet generator device
(6) comprising a plasma torch connected to gas supply and
electricity power supply means (13) suitable for
operating said plasma torch, said plasma torch being
fastened to the duct (11) of an above-mentioned display
device (5, 8).

2. Tooling according to claim 1, characterized in that it
comprises a first set of tooling (4) constituted by a
first display device (5) coupled to a plasma jet
generator device (6), and a second set of tooling (7)
constituted by a second display device (8) coupled to a
suction device (9).
3. Tooling according to claim 1, characterized in that
the suction device (9) and the plasma jet generator
device (6) are coupled to a single display device (5) so
as to form a single set of tooling.
4. Tooling according to any one of claims 1 to 3,
characterized in that the plasma torch is a cold plasma
torch.
5. A method of removing sand from a turbine engine with
the help of tooling according to claim 2, the method
being characterized in that it comprises the steps
consisting in:
inserting both the plasma torch and the duct (11)
of the first display means (5) simultaneously in the
turbine engine in such a manner that the torch and the
free end (12) of said duct (11) are situated facing a
surface to be cleaned;
using the plasma torch to detach a layer of
particles, e.g. such as a layer of sand, from the surface
to be cleaned;
inserting both the suction duct (16) and the duct
(11) of the second display means (8) simultaneously into
the turbine engine in such a manner that the ends (17,
12) of said ducts (16, 11) are situated facing the
surface to be cleaned; and
using the suction duct (16) to suck up the
previously detached particles.
6. A method of removing sand from a turbine engine with
the help of tooling according to claim 3, the method
being characterized in that it comprises the steps
consisting in:
-inserting the plasma torctt, the duct (16) of the
suction means ( 9 ) , and the duct (11) of the display means
(5) simultaneously into the turbine engine in such a
manner that the torch and the free ends (17, 12) of said
ducts (16, 11) are situated facing a surface to be
cleaned;
-using the plasma torch to detach a layer of
particles, e.g. such as a layer of sand, from the surface
to be cleaned; and
-using the suction duct (16) to suck up the
previously detached particles.