Note: Descriptions are shown in the official language in which they were submitted.
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A SAFETY ANNULAR HEAT EXCHANGER FOR INCOMPATIBLE FLUIDS
FIELD OF THE INVENTION
. 5 The present invention relates to those heat
exchangers for so called incompatible fluids. By the
phrase "incompatible fluids", it should be understood ~.
such types of fluids that, when put together, are able
to react in a dangerous manner, for example by self
ignition, or stlll such types of fluids that, when mixed
in certain conditions, are able to generate toxic
compounds, or compounds having any other drawbacks.
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BACKGROUND OF THE INVENTION
~or having an effective heat exchange, the prior
art has tought heat exchangers comprising a vat having
an open side on which is fastened a header tank with
hair pin shaped tubes secured thereto, those tubes
extending within the vat. -
In the above known embodiment, a first fluid ,
circulates in the vat, which vat is possibly provided
with baffles, while a second fluid circulatès in the
tubes, which second fluid is brought at one end of the
tubes by a first collector box and collected from the
second end of the tubes by a second header tank.
The known heat exchangers of the above mentioned
type are satisfactory regarding the heat exchange ;
capacity they have. But it may happen that leaks will
i occur, in particular at the feet of the tubes engaged in
the header tanks closing the vat in which circulates the
first fluid. Leaks may also be provided through
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perforations of the thill walled tubes llaving walls
generally of about 6-8 tenths of a millimeter.
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Actually, experiments have shown that fluids ~:
circulating in heat exchangers can carry waste products,
and particularly metal chips. This is for example the
case for lubricants of gear mechanisms. It thus happens -:~
sometimes that such metal chips will remain at a fixed .
place in the circuit of the heat exchanger while being
submitted to a movement making that these metal chips ~'
produce a milling action which may cause a perforation :.
of the wall of the circulation duct.
Present safety requirements in particular in the
aeronautical industry, make that some components, such
as are the heat exchangers, must be able to work during
many hundreds of thousands of hours without any failure .
occurring because of these heat exchangers.
It has thus been found that the hereabove
mentioned problems concerning the safety of use while ,~
ensuring a very good effectiveness with respect to the ~
heat exchange lead to avoid to use heat exchangers of ~ ::
the tubular core type.
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PURPOSE AND SUMMARY 0~ THE INVENTION ~ :
The invention provides a new heat exchanger which
takes into account the hereabove mentioned drawbacks, ;~;.
and has such a construction that any communication ~ .
between different fluids is effectively eliminated,
possible leak being produced only toward the outside of
- the heat exchanger even if some of the walls of the
circulation ducts that it comprises are submitted to an
accidental abrasion. i
According to the invention, the safety annular
heat exchanger for incompatihle fl~llds comprises a
hollow body having one end closed by a bottom, a sealed
bottle within this body, with this sealed bottle being
rigidly and sealingly fixed to the hollow body, the
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bottle having at least one wall with two sides, heat
dlssipators belng provided on each of these two sides,
~:~i and thls bottle forming a separation wall between a
first and a second fluid respectively circulating on
either side of the at least one wall of the bottle
¦ between an input channel and an output channel of the
hollow body for one of the fluids and between an input
¦ duct and an outpu-t duct for an other one of the fluids.
I According to other features of the invention,
means are provided for avoiding that a troublesome heat
3 exchange can be produced between the admission and
delivery ducts for one fluid and the circulation ducts
of thls one fluid circulating according to a
j counter-flow direction around the admission ducts.
There is also provided means carrying into effect
thick or composite walls for the heat exchange between
the two fluids, the wall thickness of these walls being
substantially greater than a corresponding wall
thickness coming from a theoretical computation for
ensuring an optimum heat exchange between two fluids
circulating on either side of said walls. The bottle at
least has thus a wall thickness between about one
i millimeter and a plurality of millimeters.
Further means are also provided according to the -
invention so that it is possible to make the walls
ensuring the heat exchange between the two fluids while ~f
providing inner leak channels leading to outside of the
heat exchanger.
Furthermore, the invention provides that the heat
exchanger can have various shapes. in particular a
circular shape, a paralleleliped shape or an arcuate -~
shape, in order to adapt the heat e~changer to any
suitable machine, for example a jet englne in ~ ;
aeronautics or other similar machines.
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descriptlon.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention are shown, as non
limitative examples, in the accompaning drawings,
wherein :
Fig. 1 is an elevation cross-sectlon of an ;~
embodiment of the heat exchanger according to the
invention.
~3 Fig. 2 is a partial cross-section illustrating an
advantageous embodiment of one of the elements shown in
15 Fig. 1.
Fig. 3 is an enlarged half cross-section taken ~ '
substantially along line III-III of Fig. 2. -`~
Fig. 4 is a half cross-section similar to Fig. 3
illustrating a variant of embodiment. ~`
Fig. 5 is an elevation cross section similar to
Fig. 1 illustrating a development of the invention. ;
Fig. 6 is an elevation wiew according to line
VI-VI of Fig. 5.
Fig. 7 is a partial elevation cross-section of
the heat exchanger of Fig. 5 in an embodiment ~ ~
illustrating a development of the invention. ~ '
Fig. 8 is a cross-section taken along line -
VIII-VIII of Fig. 7. -;~
Fig. 9 is a partial cross-section illustrating ~ ~`
the development of Fig 5 in an embodiment similar to ~ ` ~.
that of Fig. 1. `~
Fig. 10 is a part-lal elevation cross-section `
similar to Fig. 9 illustrating a further development of
the invention.
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Flg. 11 ls a partlal cross-sectlon slmllar to
Flg. 9 illustrating a slmplified embodiment. :
Fig. 12 ls a cross-section taken along llne
XII-XII of Flg. 5 lllustratlng, ln cross-sectlon, a
partlcular embodiment of the heat exchanger of
Flgs. 1-11.
DESCRIPlION OF PREFERRED EMBODIMENTS
..
I 10 The heat exchanger shown ln the drawings
j comprlses a body 1 made by moulding of a metal, for -~
¦ example aluminum or aluminum alloy, "Inconel", or still
by machining of metal, either a light alloy, or a
stainless steel, titanium or any other suitable metal
for the use considered.
The body 1 forms an envelope 2 of a general
cylinder shape, and which is closed at one end by a
bottom 3 formed in one piece with the envelope 2. `
The body 1 delimits an inner cylindrical wall 4
having ends provided with distributing and collecting ~
recesses 5 and 6. The recess 6 has an annular shape - .
while the recess 5 can extend only on a part of the
periphery of the cylindrical wall 4.
The recesses 5 and 6 communicate with an input `~
channel 7 and an output channel 8, respectively,
designed to be connected to connection members leading ~ ``
to admission and discharge ducts (not shown).
In the embodiment shown in the drawings, the body
1 is provided with a fixation flange 9 designed to be
mounted on any suitable support (not shown).
The body 1 could, without departing from the
scope of the invention~ be an integral part of a carter
of a motor or an other similar device.
The end of the body 1 which is opposed to the
bottom 3 forms a bearing surface 10 for a flange 11
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;~ formed at one end of a sheath 12 closed by a bottom 13
-~ so to make a sealed bottle. The sheath 12, the flange 11
and the bottom 13 are made as a slngle uni-t, preferably
of a light alloy, manufactured by a machining method
5 . making that the wall of the sheath is relatively thick
, and always greater than the thickness which is computed .
; for resisting to mechanical efforts, and the thickness
. of the wall of the sheath is at least about 1 to 3 mm.
The machining method for manufacturing the sheath
12, bottom 13 and flange 11 is choosen among the methods
making that no creek is formed in the fluid separation
wall that forms the whole unit in the shape of a bottle
as above explained.
A machining of a solid part constitutes a ,~
suitable embodiment, as well as an embodiment comprising
rolling of the sheath 12 and soldering of the bottom 13. ~ ;
An embosslng or forging method can also be used.
~. A gasket 14, for example a o-ring is installed ~ .
? between the flange 11 and the bearing surface 10 of the body 1. ` :
As Rhown in the drawings, the respective sizes of ~;:
the sheath 12 and body 1 are choosen so that a space 15 `~
will exist between the lnner wall of the bottom 3 and -
the outer wall of the bottom 13, and also between the `, -;~
outer wall of the sheath 12 and the inner wall of the
envelope 2 of the body 1.
Heat dissipators 16, formed for example by cor- ,:
rugated sheet, a plurality of fins or points, or other
similar members, are protruding from the inner wall of
, 30 ~ the sheath 12 and, samely. hea-t dissipators 17 are r
protruding from the outer wall of the sheath 12 to - , ;
extend on all the useful length thereof.
When the heat dissipators l6 and 17 are made by
means of corrugated strips, well known in the heat -
exchanger art, they are connected to the sheath 12, for
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example by brazing. When the heat dissipators 16 and 17
are formed by fins, or points, they are manufactured by
a machining method, for example by milling in a
machining center providing a fluid separation wall
partly made of the sheath 12 and the bottom 13. One will
not depart from the scope of the invention by maklng the
sheath 12 and the heat disslpators 16 and 17 by means of
a casting method, a forging method, a spinning method,
or by an other suitable method.
The heat dissipato:rs 17 are surrounded by a
sleeve 18 which can be made of metal or, possibly, -~
synthetic material, which sleeve 18 is extending on all
the useful length of said heat dissipators 17 while
providing an annular free space with the inner wall of
the flange 11 and with the inner wall of the bottom 13 ;~
of the body 1, respectively. `: ~-
A sealing gasket 19 is preferably installed
between the sleeve 18 and the cylinder wall 4 of the
envelope 2, which sealing gasket 19 is possibly provided
so to ensure only a relative tightness. ;~
In a similar manner to what has been described in
the above disclosure with respect to the heat dissipator
17, a second sleeve 20 is engaged within the heat `
dissipator 16. ~.
The second sleeve 20 extends on all the useful
length of the heat dissipator 16, and is supported in a
neck 21 of a distributing cover 22 applied on the outer ~ ;
wall of the flange 11.
A sealing gasket 23 is installed between the
! 30 distr,ibuting cover 22 and the flange 11. Fixing and
holding means 24, for e~ample screws or bolts, are
provided for securing the cli.ctributln cover 22 on the ~i~
flange 11 and for securillg tl~e flange ll on the body l.
The distributing cover 22 forms an inlet duct 25,
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arranged preferably coaxlal to the sheath 12, and an
annular manlfold 26 communlcatlng wlth the annular space
27 formed between the second sleeve 20 and the lnner
. wall of the sheath 12.
The manifold 26 conducts to an output duct 28.
The above described heat exchanger is prlnclpally -~
designed for enabling heat exchange between incompatible
flulds, whlch means fluids that should in no case be put :
ln contact together, as this can be the case between a ,
fuel product, for example kerosene, and the lubrication
oil of members of an englne or of a transmission when ~'
these two fluids are at very different temperatures, the -~;
lubrication oil having for example to be cooled-down by :
the fuel supplied to the engine.
3 15 The first fluid, for example the fuel, is :
supplied into the heat exchanger through the inlet duct
25 according to arrow Fl. The first fluid passes then
ln the space 27 formed between the second sleeve 20 and ~.
the outer surface of the sheath 12, which space 27 -~`.
contains the heat dissipator 16. r ~,^
This first fluid is then supplied to the annular -
manifold 26 and then to the outlet duct 28. 1
The second fluid, for example a lubricant oil, is
supplied according to arrow F2 to the inlet channel 7 : ~
that directs the second fluid to the annular recess 6 i ~`
which forms a distributor that distributes and conducts
: this fluid within the sleeve 18, thereby flowing outside
of the sheath 12 along the heat dissipators 16 and 17 ~ j:
carried by the sheath 12. ::`-
The space 15 separating the bottom 13 of the
sheath 12 from the bottom 3 of -the body 1 forms a
manifold for the second fluid. that is thus supplied -to ~:
the recess 5 and then into the outlet channel 8.
The preceding disclosure shows that no passage ~.
whatsoever can exist between the circuit of the first
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fluid and that of the second fluid. If a leak would
occur, the leak could only be produced between the
flange 11 and the bearing surface 10 of the body 1, in
case the gasket 14 is defective. But, in this case, the `~.
5 . second fluid would be conducted to the outside without ~,-
possibly rejoining a part of the circuit of the first ~
fluid. ~;
3 In a like manner, a leak in the circuit of the
first fluid could only be produced between the outside
of the flange 11 and the gasket 23 of the distributing
cover 22. In this case, such a possible leak which would
be caused by a defect in the gasket 23 could conduct the `~
first fluid only to the outside without this first fluid ~
being able in any case to come into the circuit of the ,.
second fluid.
In the above described example, the two fluids
are circulating in a counter-flow direction. But one
will not depart from the scope of the invention by using ~
another way of circulation between the two fluids for ~`
means usual in the art. It is in particular possible to .
. arrange partition walls at ends of some of the heat
dissipators for establishing a zigzag flow of one and/or ;.`
the other of the two fluids. ~ ;~
The sleeve 18 can be freely mounted relative to ~
the envelope 2 and heat dissipators 16, or the sleeve 18 ;
can be fixedly mounted with the envelope 2 while "~
remaining free with respect to the heat dissipators 16, ~ `~
or still the sleeve 18 can be fixedly mounted with the . ~`
-is~! heat dissipators 16 while being free with respect to the
envelope 2. It is also possible not to use the~sleeve 18 :~`
i~ if the length of the distributing recess 6 is small
relative to the len,th of the heat flissipators 16, which
is illustrated for the heat dissipato1-s shown at 16a in
the embodiment to be described later on in reference ~ ~
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Samely, the second sleeve 20 is provlded to be -
slidable with respect to the heat dissipators 16 or, if
the sleeve 20 is fixedly moun-ted with the heat
dissipators 16, the second sleeve 20 is provlded to be
movable with respect to the neck 21, thereby also
avoiding stresses which could occur because of
differential heat dilatations. `-
In the above disclosure, it has been mentioned
that the sheath 12 has a thick wall, for example of
about 1 to 3 mm in order to reduce, or even eliminate, -~
I any risks of communication between the circuit of the
first fluid and that of the second fluids. ~"~
~or still more eliminatlng a risk of accidental
communication between the two circuits, Figs. 2 to 4
illustrate means forming some developments of the
invention for obtaining thick walls with good heat
conductivity.
According to Figs. 2 and 3, the sheath 12a of the
bottle is formed by two tubular members 29, 30 provlding
therebetween an annular space 31. The tubular members ~ `
29, 30 are connected together on a greater part at least
of their length by heat conducting members 32, for
example strips, which are corrugated or have an other
suitable shape, and which can be brazed or connected by
any other suitable means to those tubular members 29, 30.
On an other hand, the tubular members 29, 30 are
connected together at least at their ends by means of
rings 33, 34, which are brazed or soldered in order to
provide an absolute tlghtness.
Various means are kno~n in the art for obtaining
such an absolute tightness. and it is for example
possible to use an electron heam soldering.
The annular space 31 advantageously communicates
with a vent channel 35 provided in the flange 11. In
this manner, in case one of the tubular members 29 or 30
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has a leak, the flrst fluid fl or the second fluid
f2 will enter the annular space 31 and will be
evacuated by the vent channel 35, which makes possible
~ to immediately detect the anomaly.
r 5 Fig. 4 shows that the heat conducting members 32 -;
~ can be made by fins 32a possibly formed by moulding
.;, together with one of the tubular members 29 or 30, so to
} divide the annular space 31 in longitudinal channels 31a.
~ Fig. 5 illustrates a development of the invention
,( 10 permitting to manufacture heat exchangers having a great
output delivery.
: In the embodiment of Fig. 5, the sheath 12 made
. as above described in relation with Fig. 1 comprises an
open end provided with a ring 36 in which a socket 37 is
centered, the socket 37 having thick walls, i.e. walls
~ of a thickness similar to that of the sheath 12.
`~ O-ring sealing gaskets 38 providing an absolute .
thightness are installed between the ring 36 and the .
socket 37, the free end of which socket 37 forms a
flange 39 provided with o-ring sealing gaskets 40 which
are supported on a bearing surface 41 of the end la of
the body 1. The gaskets 40 provide also an absolute
tightness.
. In this embodiment, the body 1 is provided with a ~ .
removable bottom 3a that is fixed, for example bolted,
on the body 1, with an interposition of o-ring gaskets ~
; ~ 42 providing an absolute tightness. ~-
, ~ The sleeve 12 is provided, as in the embodiment .
. ~ of Fig. 1, with heat dissipators 16 and 17 and, in a
similar manner, the socket 37 is provided with heat ~- -
dissipators 16a and 17a. respectively, extending on both
of its sides. ` ;~ ~;
The heat dissipators 17 and 17a are supported on
the inner wall 43 and outer wall 44 of a member forming
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an annular duct 45 extending from a distributing chamber
46 opening in the inlet duct 25 of the body 1. ~.;
The drawings show that sealing gaskets 47 are
installed between the inner wall of the inlet duct 25
5 - and the outer wall of the distributing chamber 46. The
tightness which is thereby provided is not necessarily `~
an absolute tightness.
The end la of the body 1 forms an outlet chamber ~ '
48 provided with an outlet nozzle 49.
At least one aperture 50 is provided between the .
chamber 46 and the annular duct 45 for communicating the
chamber 48 with a chamber 51, the chamber 51 then -
communicating with the annular spaces separating the r
inner wall 43 and outer wall 44 of the duct 45 from the
outside of the sheath 12 and the inside of the socket 37.
The above disclosure shows that the walls 43, 44
fulfill the functlon of either one of the sleeves 18 or
20 of the embodiment according to Fig. 1, in addition to
functions to be described later.
The member that forms the chamber 46 and the
walls 43, 44 of the annular duct 45 can be made of
various materials, for example this member can be made
of metal or of composite or plastic material, according
to temperature of the fluids designed to bathe this -~
member. Preferably, the above member is made of a
material having a low heat conductivity, which can be
obtained as described later-on with reference to Fig. 7.
The drawings show that the annular duct 45 is
open at its end opposite the chamber 46 so that the
fluid, which is supplied -to the inlet duct 25 according
to arrow F2, is then suppliod inside the annular duct
45 and goes out therefrom at lts o~en end as shown by
the arrows, and is conducted to the outlet chamber 48 in
a counte:r-flow direction by following the heat
dissipators 17 and 17a.
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¦ Because of the low conducting nature of the walls
43 and 44, the heat exchange is small between the fluld
circulating between the walls 43 and 44 and the fluid
circulating outside the walls 43 and 44.
To correspond to what has been discussed above -~
relatively to the working of the heat exchanger of Fig.
1, it is assumed that the fluid circulating according to
the arrow F2 is the second fluid, for example a
lubricant, having to be cooled down by a first fluid,
for example a fuel having to be supplied to the
combustion chamber of an engine.
In the embodiment of Fig. 5, the first fluid is
supplied to the input channel 7 according to the arrow '~
Fl. This first fluid is directed, as shown by the ~ ;
arrows so .hat the first fluid will circulate around the ,~;
socket 37 along the heat dissipators 16a in a ~ i
counter-flow direction to the first fluid circulating
along the heat dissipators 17a.
The first fluid is therefore supplied to a
passage 52 in the bottom 3a and leading to a median
mouth 53 opening inside the bottle that is formed by the 1~
sheath 12, which means : inside the sleeve 20 surrounded ~ ~-
by the heat dissipators 16 secured to the sheath 12. `.`~
Thus, the first fluid is supplied into the bottom -
13 of the bottle and directed therefrom to the inside of
the sleeve 20. This first fluid circulates then along ~-
the heat dissipators 16 on the outer wall of the sheath
12, which means that the first fluid then circulates in ~`~
a counter-flow directlon to the second fluid that
circulates according to the arrow F2 along the heat
dissipators 17 which are carried by the outer wall of
the sheath 12.
The first fluid is finally supplied into a '~
manifold 54 (Figs. 5 and 6) defined by the removable ,~
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bottom 3a, and is thus dlrected to the outlet channel 8
of the body 1.
As this is clear from the above disclosure, the
first fluid always circulates outside of the socket 37
and inside of the sheath 12 so that an absolute
tightness is only necessary between these two parts,
i.e. at the annular gaskets 38 and also between the
socket 37 and the bearing surface 41 of the end la of -
the body, which is provided by the o-ring sealing
10 gaskets 40.
The second fluld, for its part, circulates only
inside the socket 37 and outside the sheath 12. The
risks of communication are thus extremely reduced since
~'3` they are caused, either by a possible porosity of the
s 15 socket 37 or of the sheath 12, or by an accidental
perforation which could be caused by the presence of ~;~
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- waste products as for example metal chips. ~
There is hereinafter described how, according to ~:
, the invention, it is now possible to get rid of this
20 risk.
, In order to still increase tightness between the
~; socket 37 and the sheath 12, it is advantageous to ~oin
the ring 36 to one end to the socket 37 by a weld 55
(Fig. 9), the good carrying out of which weld can easily
25 be checked by means known in the art.
In this case, it is also advantageous as shown in
~,~ Fig. 9, that the flange 39a of the socket 37 is
tightened between complementary flanges 56 and 57,
respectively of the body 1 and of the end la of the body
30 1. There is then used, for maintaining the soclcet 37,
.
'` the same means as that shown in Fig. 1 for maintainlng -
the sheath 12.
Also as in Fig l. sealing gaskets 14 and 23 are
provided and applied on the flange 39a. According to
35 this embodiment, the only one possibility for the fluid
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fl to leak would be to leak between the flange 39a and
the flange 56, which means outside of the body 1 of the
heat exchanger and, samely, the only one possibility for
the fluid f2 to leak would be to leak between the
flange 39a and the flange 57, which also means outside
~ of the heat exchanger.
¦ It has been mentioned in the above disclosure
that it i5 advantageous to reduce as far as possible the
~ heat exchange between the annular duct 45 and the heat
1 10 dlssipators 17 and 17a, respectively connected to the
I sheath 12 and to the inner wall of the socket 37. . ;
Figs. 7 and 8 lllustrate an embodiment enabling
to reduce such a heat exchange at a very small value. In
this case ! the member defining the annular walls 44 and
45 is made so that said walls are respectively formed by ~;
two concentrical tubes 44a, 44b and 45a, 45b which are
I spaced apart by means of spacers 58.
¦ One at least of the tubes 44a, 44b and 45a, 45b
has one or more apertures 59 so that some fluid f2, -i
that circulates inside the annular duct 45, or outside ~
the annular duct 45, will fill the space separating the `~-
concentrical tubes 44a, 44b and 45a, 45b. ~`
The apertures 59 are small so that circulation of `~
the fluid contained between said concentrical tubes is
reduced and even nil. In this manner, the fluid itself
forms a heat screen that limits conduction.
Figs. 7 and 8 also show an embodiment enabling an i~
escape outside of the heat exchanger of one and/or the
other fluid fl, f~ when the socket 37 is arranged as
I ~ 30 described by reference to Fig. 5. l.e. when the socket
j 37 comes to bear on the ring 36 of the sheath 12 through
the gaskets 38 and bears. qn an other hand. on the ; ;-
bearing surface 41 through the gaskets 40. :
For this purpose, the socket 37 that is ¦
relatively thick for the same reason as the sheath 12 is
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moreover provlded with a small longitudinal bar 60
havlng a channel 61 thereln communlcatlng wlth ducts 62, -
63 openlng respectlvely between the gaskets 40, on one
hand, and between the gaskets 38, on the other hand.
The duct 62 ls arranged to wards a discharge
channel 64 in the end la of the body 1. In such a
manner, a leak of the fluid fl which would occur in
case of failure in one of the gaskets 38, would supply, ~
the fluid through the ducts 63, 62 towards the channel -
64. Samely, a leak of the fluid f2 which would be -
caused by a deficiency in the other gasket 33 or in one
of the gaskets 40 would supply this fluid towards the
discharge channel 64.
Fig. 10 illustrates a development of the
invention by which there is get rid of the risk of leaks
through porosity or through a milling action possibly
caused by waste products.
As shown in the drawingsl the sheath 12, as well
as the socket 37 are both made for having two walls 12a,
12b and 37a, 37b, respectively, defining annular `~
chambers 65, 66 in which are arranged heat transmission
members 67, 68. The heat transmission members 67, 68 can
be formed by fins, coiled strips, bands that have been
cut as heat disturbing elements, or still by other
members providing a good heat transmission. The heat
transmission members 67, 68 are preferably brazed to, or `~
made integral with, one of the walls of the sheath 12 or
socket 37.
The annular chambers 65, 66 are on an other hand
connected together br the duct 63 as described above
with reference to Fig. 7 and the duct 64 is provided in
the flange 39a for communicatin witll the chamber 66 of
the socket 37 or with -the chamber 65 of the sheath 12 in
the case of embodiment of Fig. 1 which does not comprise
the socket 37. `
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i' The above dlsclosure shows that the working from
I a heat exchange poi.nt of view is not modified with
,
~ respect to the embodiments above described with
-I reference to Figs. 1, 5 and 9 and that, besides, in case
of damage to one of the walls 12a, 12b and 37a, 37b, `
~ respectively, either one of the fluids fl or f2 is `~
i~ necessarily directed outside the heat exchangers thereby
eliminating any risks of contact between the two fluids.
Fig. 11 illustrates a simplified variant of the
embodiments according to ~'ig. 5 or 9. In Fig. 11, the
same reference numerals designate the same members as
those described in the above embodiments. ~-
The body 1 is made ln order to be connected with `~r
a tightness, which can be a relative tightness, directly ~ .
to one end of the sleeve 20 surrounded by the heat ~ :
dissipators 16.
~¦ A single tube 43a is substituted to the tubes 43 ,~
and 44 of Figs S and 9, and this tube 43a is connected
through the gasket 47, the tightness of which being ~:
possibly a relative tightness, to the mouth 25 of the
end la of the body 1. ~-
The tube 43a forms a separation wall between the
heat dissipators 17 and 17a of the outer surface of the
sheath 12 and inner surface of the socket 37, thereby ;
defining a double circuit between said sheath 12 and
sockets 37. One of the fluids can be caused to circulate
from the mouth 25 by following the arrows F2 shown in
a full line to be supplied to the outlet duct 49, or
this fluid can be caused to circulate from the outlet
l I 30 duct 49 by following the arrows illustrated in phantom, :'~
i.e. in a direction contrary to that of F2. On an -~
other hand, the o-ther fluid can ~l.so circulate in one or
in the other direction according to the arrows Fl. It
is therefore possible to provide circulations both in a
2 ~ o ~
18
same directlon, in a counter-flow direction or at a
cross-flow direction.
In the preceding disclosure, it has been
mentioned that the envelope 1, the socket 37, the part
S delimiting the annular duct 45, the sheath 12, the
sleeve 20, as well as the hereabove described members
associated therewith, have an annular cross-sectlon.
Fig. 12 illustrates that it is possible to provide other
sectional shape while carrying into effect all the above
described features.
In this respect, Fig. 12 shows that the heat
exchanger, in i-ts embodiment shown in Fig. 5, can have
an arcuate shape in order to be adaptable to a support
member of a general cylinder shape, as this is the case
for the walls of ~et engines in aeronautics.
In Fig. 12, as in the preceding figures, the same -
reference numerals designate the same members as those ~'7'
detailed in the above disclosure. -
It is obvious that other sectional shapes can be
samely provided, the heat exchanger having possibly a
rectangular cross-section which can be more or less
flattened.
In the above disclosure, lt has been explained
that an absolute tightness should be obtained at various .
places of the circuits. For other parts of the circuits,
for example between the ring 36 and the passage 52, or
at the gasket 47, only a relative tightness should be
provided. This relative tightness can be made by any
suitable means known in the art, such as by gaskets, a ;~;
, 30 tight fitting, interposition of an impregnation product,
etc
.
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