Method and device for thermally insulating a piece of equipment

Abstract

A device for thermally insulating a piece of equipment, the device including a block of thermal insulation having at least a first hole; a deformable cover made of a gastight material and surrounding the block of insulation so that the wall of the first hole is covered by the gastight cover while leaving open the ends of first hole, the cover defining, at the second end, a first opening that communicates with the first hole and a second opening that communicates with the space situated between the insulating block and the cover; and the first and second openings of the cover being closed in gastight manner with the inside of the cover under a partial vacuum.

Claims

1. A method of thermally insulating a piece of equipment, the method comprising: a) supplying at least one block of thermal insulation presenting a shape complementary to an outside face of a portion of said equipment; b) making a first hole in said block of insulation presenting a first end opening out facing the outside face of said equipment and a second end opening out away from the outside face of said equipment; c) placing said block of thermal insulation in a deformable cover made of a gastight material such that a wall of said first hole is covered by said gastight cover while leaving the first end and the second end of said first hole open, and the cover defines, at the second end, a first opening that communicates with the first hole and a second opening that communicates with the space situated between the insulating block and the cover; d) fastening the block of insulation covered in the cover against the outside face of said portion of equipment by gastight and deformable connection means so that a space defined between the block of insulation and said portion of equipment presents a closed outline; e) connecting the first opening and the second opening to suction means; f) activating said suction means whereby an inside of the cover is partially evacuated and the cover is pressed against the block of insulation and against said portion of equipment; and g) closing the first opening and the second opening of the cover in gastight manner.

2. The method according to claim 1, wherein during step b) a second hole is formed in said block of insulation, presenting a first end opening out facing the outside face of said equipment and a second end opening out away from the outside face of said equipment; and during step c), said gastight cover covers a wall of the second hole while leaving open the first and second ends of the first hole; and prior to step e), a first pressure indicator is provided that is put into place by being enclosed in gastight manner at the location of the second end of the second hole.

3. The method according to claim 2, wherein during step c), a second pressure indicator is provided that is placed between said cover and said block of insulation.

4. The method according to claim 1, wherein said connection means comprise a pad or a tongue forming part of said cover or are constituted by an elastomer gasket adhesively bonded to said cover.

5. The method according to claim 1, wherein use is made of a plurality of assemblies, each of the assemblies comprising a block of insulation and a cover, said assemblies being suitable for covering adjacent portions of the outside face of said equipment by performing steps a) to g), and wherein said method further comprises: h) providing a heat-shrink outer bag; i) placing said bag in such a manner as to surround in part at least two of said assemblies each formed by a respective block of insulation covered by its cover closed in gastight manner; and j) heating said bag so that the bag shrinks and clamps against said assemblies.

6. A device for thermally insulating a piece of equipment, the device comprising: a block of thermal insulation presenting a shape complementary to a shape of an outside face of a portion of said equipment to be insulated, said block of insulation including a first hole presenting a first end suitable for opening out facing the outside face of said equipment and a second end suitable for opening out away from the outside face of said equipment; and a deformable cover made of a gastight material, said cover surrounding the block of insulation so that a wall of said first hole is covered by said gastight cover while leaving open the first and second ends of said first hole, the cover defining, at the second end, a first opening suitable for being closed in gastight manner and communicating with the first hole, and a second opening suitable for being closed in gastight manner and communicating with a space situated between the insulating block and the cover, and the first opening and the second opening of the cover being closed in gastight manner while an inside of the cover is under a partial vacuum.

7. The device according to claim 6, wherein said block of insulation has a second hole presenting a first end opening out facing the outside face of said equipment and a second end opening out away from the outside face of said equipment, wherein said gastight cover covers a wall of the second hole while leaving open the first and second ends of the first hole; and wherein the device further includes a first pressure indicator put into place by closing the second end of the second hole.

8. The device according to claim 7, further comprising a second pressure indicator put into place between said cover and said block of insulation.

9. The device according to claim 6, wherein the second opening surrounds the first opening.

10. The device according to claim 6, wherein said block of insulation is made of a porous material.

11. The device according to claim 6, wherein said cover is made of an elastomer material.

12. The device according to claim 6, wherein said cover is made of a material that is transparent or translucent.

13. An assembly suitable for use in isolating a piece of equipment, the assembly comprising: a device according to claim 6; and deformable connection means suitable for fastening the block of insulation covered in the cover against the outside face of said portion of equipment, while defining, between the block of insulation and said portion of equipment, a space having a closed outline.

14. The assembly according to claim 13, wherein said connection means comprise a pad or a tongue forming part of said cover or said connection means are constituted by an elastomer gasket adhesively bonded to said cover.

15. An insulated system comprising: a piece of equipment; and an assembly according to claim 13 covering the outside face of said equipment at least in part.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) Other advantages and characteristics of the invention appear on reading the following description made by way of example and with reference to the accompanying drawings, in which:

(2) FIG. 1 is a diagrammatic view of the insulation device in a first configuration and prior to performing the method in full;

(3) FIG. 2 corresponds to FIG. 1, after the method of the invention has been performed;

(4) FIG. 3 is a diagrammatic view of the insulation device in a second configuration, and prior to the method being performed in full;

(5) FIG. 4 corresponds to FIG. 3, after the method of the invention has been performed; and

(6) FIG. 5 shows a variant embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(7) As can be seen in FIG. 1, a piece of equipment 10 is covered over a portion 12 of its outside face 11 by an insulation device 100.

(8) The insulation device 100 comprises firstly a unitary block 110 of insulating material that presents a thickness, which is preferably substantially constant, a face 111 facing the outside face 11 of said equipment 10, and of a shape that is complementary thereto, and a face 112 facing away from the outside face 11 of said equipment 10.

(9) Said insulating block 110 is preferably made of a porous material such as: open-cell polyurethane foam; open-cell polystyrene foam; compacted powders (silica, perlite, . . . ); aerogels; and compacted fibers.

(10) The material must be capable of withstanding the compression force when it is placed in an evacuated gastight cover.

(11) It is possible to make insulating blocks 110 for simple shapes, and also for complex shapes by using methods based on molding, machining, water jets, lasers, . . . .

(12) The insulating block 110 has a first hole 113 having a first end 113a opening out facing the outside face of said equipment and a second end 113b opening out away from the outside face of said equipment, and preferably, as shown in FIGS. 1 to 4, in the face 112 facing away from the outside face 11 of said equipment 10.

(13) Furthermore, in preferred but non-essential manner, the insulating block 110 presents a second hole 114 presenting a first end 114a opening out facing the outside face of said equipment and a second end 114b opening out away from the outside face of said equipment, and preferably, as shown in FIGS. 1 to 4, in the face 112 facing away from the outside face 11 of said equipment 10.

(14) The insulation device 100 also has a gastight cover 120 constituted by a flexible diaphragm covering all of the faces of the insulating block 110, and including in particular the face 111 that faces the outside face 11 of said equipment 10 and the face 112 facing away from the outside face 11 of said equipment 10.

(15) Initially, the cover 120 also covers all of the wall of the first hole 113 in a manner that is continuous with the covering of the face 111 facing the outside face 11 of said equipment 10, and opening out at the second end 113b of the first hole 113 via a first opening 121. The cover 120 does not close the first end 113a of the first hole 113, which remains open.

(16) Likewise, the cover 120 has a second opening 122 that communicates with the space situated between the insulating block 110 and the cover 120, this second opening 122 opening out away from the outside face of said equipment 10.

(17) In FIGS. 1 to 3, this second opening 122 of the cover is concentric with the first opening 121 and surrounds the first opening 121.

(18) Furthermore, and in preferred but non-essential manner, the cover 120 has other openings, as can be seen in FIGS. 1 and 3.

(19) Specifically, and preferably: said block of insulation 110 has a second hole 114 presenting a first end 114a opening out facing the outside face of said equipment 10 and a second end 114b opening out away from the outside face of said equipment 10; said gastight cover 120 covers the wall of the second hole 114, leaving open the first end 114a and the second end 114b of the second hole 114; the device 100 also has a first pressure indicator (130) 130 placed so as to close, preferably in gastight manner, the second end 114b of the second hole 114;

(20) Preferably, said cover 120 is made of an elastomer material such as: polytetrafluoroethylene (PTFE or Teflon); polyethylene; polypropylene.

(21) Optionally, the cover 120 may be made more gastight by a metal deposit of aluminum.

(22) Finally, in order to connect the device 100 to the equipment 10, use is made of a connection element 140 placed between the portion 12 of the outside face 11 of the equipment 10 in such a manner as to close completely and in gastight manner the space between the portion 12 and the cover 120 covering the insulating block 110.

(23) For example, it may be a pad or a tongue forming part of the cover 120, being made of the same material as the cover 120, or it may be an elastomer gasket stuck to the cover 120 by an epoxy resin that is suitable for low temperatures. In order to improve sealing at the contact, it is possible to use a vacuum grease.

(24) The cover 120 serves to provide the equipment with sealing and with thermal insulation, and it prevents the insulating material being source of particles.

(25) As can be seen in FIGS. 2 and 4, after all of the elements constituting the insulation device 110 have been put into place, the following insulation step comprises pumping down in the first opening 121 and in the second opening 122, and then closing the first opening 121 and the second opening 122 of the cover 120 in gastight manner, e.g. by crimping, so as to maintain a pressure lower than atmospheric pressure: this forms an attachment 123 between the first opening 121 and the second opening 122 that closes the second end 113b of the first hole 113.

(26) It should be observed that in a variant embodiment that is not shown, the first opening 121 and the second opening 122 are not placed one around the other (the second opening 122 does not surround the first opening 121 and is located at another location that does not face the portion 12), and they are closed independently, so as to form two separate attachments obtained by two separate gripping operations.

(27) Thus, by means of the first visual pressure indicator 130 and via the second hole 114, it is possible to evaluate whether there is reduced pressure present in the space situated between the cover 120 and the equipment 10, as can be seen in FIGS. 2 and 4.

(28) It is thus possible to ensure that the zone situated between the cover 120 and the equipment 10 is gastight, with this being done by means of the first pressure indicator 130 closing the second end 114b of the second hole 114 in the insulating block 110. The first pressure indicator 130 is subjected to the difference of pressure between this zone and the ambient surroundings.

(29) The outline of this first pressure indicator 130 is located at the surface of the cover at the location of the second end 114b of the second hole 114.

(30) As can be seen in FIGS. 1 to 4, the insulation device 100 preferably also includes a second pressure indicator 132 placed between said cover 120 and said block of insulation 110, in order to ensure that a vacuum is maintained within the cover 120. In FIGS. 1 to 4, this second pressure indicator 132 is positioned on the face 112 facing away from the outside face 11 of said equipment 10, however it could be positioned somewhere else on the surface of the block of insulation 110.

(31) The first pressure indicator 130 and/or the second pressure indicator 132 is/are preferably (a) visual pressure indicator(s) making use of the properties of materials under compression: photoelasticity, rubber, flexible wafer.

(32) Under such circumstances, it is preferable for said cover 120 to be made of a material that is transparent or translucent, thus making it possible to read a change of appearance of the first pressure indicator 130 and/or of the second pressure indicator 132 through the cover.

(33) Thus, when it is in compression, the first pressure indicator 130 and/or the second pressure indicator 132 changes in appearance.

(34) Because of the first pressure indicator 130 positioned within the cover 120 of the insulating block 110, it is possible to know whether a partial vacuum does indeed exist inside the cover 120, and if there are a plurality of insulating blocks 110, it is possible to know whether there is indeed a partial vacuum in each cover 120.

(35) The second configuration shown in FIGS. 3 and 4 differs from the first configuration shown in FIGS. 1 and 2 in that the insulating block 110 of the first configuration (FIGS. 1 and 2) is placed on a portion 12 constituted by a face 11 that is plane or annular with a constant radius, whereas the insulating block 110 of the second configuration (FIGS. 3 and 4) is placed on a portion 12 formed by a face 11 having a reentrant corner or that is annular with a radius that varies so as to form a reentrant shoulder.

(36) Under such circumstances, the connection element 140 follows the outline of the portion 12.

(37) It should be observed in FIGS. 1 to 4 that the insulation device 100 can cover a portion of the equipment defined by any possible shape and size for a zone of the outside surface of the equipment 10, and also, particularly when the equipment 10 is in the form of a body of revolution, any annular portion of the equipment.

(38) This is shown in FIG. 5, where the equipment 10 is constituted by the casing assembly of a turbopump, that is shown in part in section in FIG. 5, the casing assembly being a body of revolution about the axis X-X and including, from top to bottom in FIG. 5, a sleeve 10a, a front casing 10b, a central casing 10c, and a turbine casing 10c.

(39) There are various zones where the propellant might leak between the sleeve 10a and the front casing 10b (zone 13) and between the central casing 10c and the turbine casing 10d (zone 14), where maintaining sealing is particularly critical.

(40) For this purpose, the various blocks of insulation that are used are as follows: a first insulating block 110a that surrounds the sleeve and the first propellant leakage zone 13 and extending axially to the segment of the front casing 10b that is adjacent to the sleeve 10a (top axial end portion in FIG. 5); a second insulating block 110b that is adjacent to the first insulating block 110a and that surrounds the front casing 110b except for its axial end portions; a third insulating block 110c that is adjacent to the second insulating block 110b and that surrounds the segment of the front casing 10b that is adjacent to the central casing 10c (bottom axial end portion in FIG. 5) and that surrounds the segment of the central casing 10c (top axial end portion in FIG. 5) that is adjacent to the front casing 10b; a fourth insulating block 110d that is adjacent to the third insulating block 110c and that surrounds the central casing 10c other than its axial end portion; and a fifth insulating block 110e that is adjacent to the fourth insulating block 110d and that surrounds the segment of the central casing 10c that is adjacent to the turbine casing 10d (bottom axial end portion in FIG. 5) and that surrounds the segment of the turbine casing 10d (top axial end portion in FIG. 5) that is adjacent to the central casing 10c).

(41) In FIG. 5, in the above-described arrangement, each of these insulating blocks 110a, 110b, 110c, 110d, and 110e is surrounded by its respective cover 120a, 102b, 120c, 120d, and 120e.

(42) Connection elements 140 are also arranged so as to close in gastight manner the space between each cover 120a, 120b, 120c, 120d, and 120e and the facing portion of the wall of the equipment 10.

(43) Finally, under such circumstances, provision is made to use one or more heat-shrink films or bags 150 for holding together a plurality (at least two) adjacent covers from among the covers 120a, 120b, 120c, 120d, and 120e.

(44) In this way, an insulated system is formed that comprises a piece of equipment 10, such as a cryogenic piece of equipment, and an assembly for insulating said equipment, which assembly covers at least part of the outside face of said equipment 10, and comprises an insulation device 100 and deformable connection means 140 suitable for fastening the block of insulation 110 covered in the cover 120 against that outside face of said portion of the equipment 10.

(45) In order to install this insulating assembly, use is also made of means for generating suction (not shown) that are suitable for being connected to the first opening 121 and to the second opening 122 in each of the covers 120a, 120b, 120c, 120d, and 120e.

(46) For the method, during step b) of making at least a first hole 113 in said block of insulation 110, a second hole 114 is also made in said block of insulation 110 presenting a first end 114a opening out facing the outside face of said equipment 10 and a second end 114b opening out away from the outside face of said equipment.

(47) Furthermore, during step c), said gastight cover 120 covers the wall of the second hole 114, while leaving open its first and second ends 114a and 114b.

(48) Likewise, prior to step e), the first pressure indicator 130 is also supplied and put into place by closing in gastight manner at the location of the second end 114a of the second hole 114.

(49) Advantageously, in preferred but non-essential manner, it can be understood that during step c) of putting the cover 120 into place, a second pressure indicator 132 is also supplied that is put into place between said cover 120 and said block of insulation 110.

(50) When use is made of a plurality of assemblies each comprising a block of insulation 110 and a cover, said assemblies being suitable for covering adjacent portions of the outside face of said equipment 10 by performing steps a) to g) of the method described above with reference to a single insulating block, said method of thermally insulating said equipment also includes the following steps:

(51) h) further supplying a heat-shrink outer bag 150;

(52) i) placing said bag 150 in such a manner as to surround in part at least two of said assemblies each constituted by its insulating block 110a, 110b, 110c, 110d, and 110e covered by its cover 120a, 120b, 120c, 120d, and 120e and closed in gastight manner; and

(53) j) heating said bag 150 so that it shrinks and clamps onto said assemblies.

(54) The solution of the present invention makes it possible to provide a part (a piece of equipment 10) with thermal insulation and gastight sealing against the ambient environment so as to protect against condensation, frosting, and cryopumping.