Shell and tube heat exchanger

Abstract

The invention relates to a shell and tube heat exchanger (100) comprising: a housing (2) through which a first fluid is intended to pass; and a removable tube stack (1) for circulation of a second fluid, the tube stack (1) comprising: a front header (11) comprising a front housing (18), a front base (19), a front orifice for entry of the second fluid, and a front tubular plate (14) secured to the front housing (18); an aft header (12) comprising an aft housing (20), an aft orifice for the exit of the second fluid, and an aft tubular plate (15) secured to the aft housing (20); a tube bundle (13) comprising a stack of tubes for the passage of a second fluid and configured such that the second fluid passes only once through the housing (2) between the front orifice and the rear orifice.

Description

[0001] The invention relates to a shell and tube heat exchanger.

[0002] Different types of shell and tube heat exchangers are known for cooling gases with water. This type of exchanger can be used to cool helium, especially when this gas has been heated by a compressor. The TEMA standard developed and maintained by the "Tubular Exchanger Manufacturers' Association" is also known. This standard defines the main types of exchangers used in industry.

[0003] The problem with these known types of exchangers is that it is not possible to use removable tube bundles while providing at the same time minimum load losses on the tube side and maximum sealing on the tube side.

[0004] The object of the present invention is to effectively eliminate these drawbacks by proposing a shell and tube heat exchanger extending along a first longitudinal axis between a front part and a rear part, the exchanger comprising:

[0005] a housing defining an internal volume designed to allow the first fluid to pass therethrough; and

[0006] a removable tube set extending along the first longitudinal axis and defining a circuit for the circulation of a second fluid, the removable tube set comprising:

[0007] a front header defining a front chamber for the second fluid, the front header comprising a front shell, a front base that is a single piece or assembled by welding with the front shell, a front orifice for the second fluid to enter or leave, a front conduit that opens to the front orifice and is a single piece or assembled by welding with the front shell, and a front tubular plate that is integral with the front shell;

[0008] a rear header defining a rear chamber for the second fluid, the rear header comprising a rear shell, a rear orifice for the second fluid to enter or leave, a rear duct leading to the rear orifice and being in one piece or assembled by welding with the rear shell, and a rear tubular plate integral with the rear shell;

[0009] a tube bundle comprising a tube set for the passage of the second fluid and configured so that the second fluid passes through the housing only once between the front orifice and the rear orifice,

[0010] The front tubular plate is a single piece or assembled by welding with the front shell, the rear tubular plate is a single piece or assembled by welding with the rear shell, and the tube bundle is a single piece or assembled by welding with the front tubular plate and the rear tubular plate.

[0011] This allows the tube group to slide relative to the housing and therefore to be easily removed, i.e. to be taken out of / inserted into the housing. Although the tube group can be removed from the housing, this type of exchanger offers minimal load losses at the tube group. In fact, the fluid to be cooled circulates only once inside the tubes of the bundle, from the front part to the rear part of the exchanger. This type of exchanger also offers maximum sealing at the tube group. In fact, the fluid circulating inside the tubes of the bundle cannot escape towards the atmosphere.

[0012] According to one embodiment, the first fluid is a cooling fluid.

[0013] According to one embodiment, the first fluid comprises a liquid, in particular water.

[0014] According to one embodiment, the second fluid is intended to be cooled during its passage through the exchanger.

[0015] According to one embodiment, the second fluid comprises a gas, in particular helium.

[0016] According to one embodiment, the front base is curved.

[0017] According to one embodiment, the front base extends substantially in a plane orthogonal to the first axis and intersects the first axis.

[0018] According to one embodiment, the front manifold includes a front manifold flange, which is in particular a single piece or assembled by welding with the front outer shell or with the front tubular plate so as to allow the front manifold to be fastened to the front flange of the shell, and the front manifold flange in particular has an inner diameter that is substantially the same as the front flange of the shell.

[0019] According to one embodiment, the exchanger comprises a front seal interposed between the front header flange and the front flange of the casing so as to allow sealing with respect to the first fluid.

[0020] According to one embodiment, the rear manifold comprises a converging profile which converges on at least a portion of the first longitudinal axis as it proceeds along the first longitudinal axis in a direction from the front portion towards the rear portion, the portion being in particular between the rear tubular plate and the rear orifice, the rear housing being in particular conical.

[0021] According to one embodiment, the front header comprises a gripping unit for the passage of a lifting tool which allows the removal of the removable tube set from the housing.

[0022] According to one embodiment, the exchanger comprises means for sealing relative to the first fluid, the sealing means being positioned in particular between the rear header and the rear opening of the casing.

[0023] According to one embodiment, the sealing device comprises a lining, which is especially fitted to be clamped between the rear tubular plate and the inner wall of the housing, and the sealing device especially comprises a clamping ring, which is integrally fitted with a shoulder of the housing.

[0024] As a variant, the sealing device comprises a bellows fastened, in particular screwed, to the housing, with first O-ring seals being placed between the housing and the bellows, and the bellows are also fastened, in particular screwed, to the rear manifold, with second seals, in particular O-ring seals being placed between the bellows and the rear manifold.

[0025] As a variant, the sealing device comprises bellows in one piece or assembled by welding with the housing, which are also screwed onto the rear header, wherein a second seal, in particular an O-ring seal, is interposed between the bellows and the rear header.

[0026] According to one embodiment, the front duct extends along a second axis forming an angle greater than 45°, in particular substantially equal to 90°, with respect to the first axis.

[0027] According to one embodiment, the rear duct extends substantially along the first axis.

[0028] According to one embodiment, the housing is free of baffles.

[0029] According to one embodiment, the tube bundle comprises baffles which are fastened in particular to the outer wall of at least one of the tubes.

[0030] According to one embodiment, the front header has no removable cover.

[0031] According to one embodiment, the housing is of the “single-passage” type, in particular of the “E” type according to the “TEMA” standard.

[0032] According to one embodiment, the front header is of type "C" according to the "TEMA" standard, and the front header does not have a removable cover.

[0033] According to one embodiment, the rear header is of type "P" according to the "TEMA" standard, and the rear header does not have a removable cover.

[0034] According to one embodiment, the tube stack has no seal between the front outer shell and the front tubular plate.

[0035] According to one embodiment, the tube stack has no seal between the rear outer shell and the rear tubular plate.

[0036] According to one embodiment, the maximum outer diameter of the rear header is smaller than the minimum inner diameter of the housing.

[0037] According to one embodiment, the rear header has dimensions that allow the rear header to slide relative to the housing along the first axis.

[0038] According to one embodiment, the tube set is designed to be removable from the housing, the set being in particular fitted to slide relative to the housing, for example via a front part.

[0039] According to one embodiment, the housing comprises a front housing flange designed to abut the front header flange when the tube group is assembled in the interior of the housing so as to allow the front header to be fastened to the housing, in particular by at least one detachable fastening system.

[0040] The invention will be more clearly understood by reading the following description and by studying the accompanying drawings, which are provided for illustration only and do not limit the invention in any way.

[0041] [ Figure 1 ][ Figure 1 ] is a schematic representation of an exchanger according to the present invention;

[0042] [ Figure 2 ][ Figure 2 ]yes[ Figure 1 ] schematic representation of the exchanger in an intermediate removal position;

[0043] [ Figure 3 ][ Figure 3 ] is a schematic representation of a first embodiment of a sealing device;

[0044] [ Figure 4 ][ Figure 4 ] is a schematic representation of a second embodiment of a sealing device; and

[0045] [ Figure 5 ][ Figure 5 ] is a schematic representation of a third embodiment of the sealing device.

[0046] Identical, similar or like elements retain the same reference numerals between the various drawings.

[0047] [ Figure 1 ] represents a shell and tube heat exchanger 100 extending along a first longitudinal axis 40 between a front portion (to receive a second fluid) and a rear portion (to convey the second fluid once it has been cooled). The exchanger 100 comprises a shell 2 defining an internal volume intended to allow a first fluid, such as a cooling fluid, for example a liquid such as water, to pass through the exchanger.

[0048] The exchanger 100 also comprises a removable tube group 1 extending along the first longitudinal axis 40 and defining a circuit for the circulation of a second fluid such as a gas, for example helium or neon or nitrogen, or a mixture comprising at least one of helium, neon, nitrogen, or any other suitable mixture.

[0049] Group 1 includes:

[0050] a front header 11 defining a front chamber which in this case serves as a distribution chamber for the second fluid, comprising a front shell 18, a front base 19 which is in one piece or assembled by welding with the front shell 18, a front orifice for the second fluid to enter the front chamber, a front duct 10 which opens into the front orifice and is in one piece or assembled by welding with the front shell 18, and a front tubular plate 14 which is integral with the front shell 18;

[0051] a rear header 12 defining a rear chamber which in this case serves as an outlet chamber for the second fluid, comprising a rear casing 20, a rear orifice for the exit of this second fluid, a rear duct 21 opening into this rear orifice and being in one piece or assembled by welding with the rear casing 20, and a rear tubular plate 15 integral with the rear casing 20;

[0052] A tube bundle 13 comprising a set of tubes for the passage of the second fluid and configured so that the second fluid passes through the housing 2 only once, between the front orifice and the rear orifice.

[0053] The front tubular plate 14 is a single piece or assembled by welding with the front outer shell 18. The rear tubular plate 15 is a single piece or assembled by welding with the rear outer shell 20. The tube bundle 13 is a single piece or assembled by welding with the front tubular plate 14. The tube bundle 13 is a single piece or assembled by welding with the rear tubular plate 15.

[0054] The front conduit 10 is an inlet conduit for a second fluid. The inlet conduit comprises a front conduit flange 16 to allow fastening to a front connection flange 30 of an inlet for the second fluid. A seal is interposed between the front conduit flange 16 and the front connection flange 30.

[0055] The front duct 10 extends along a second axis 41 which is perpendicular to the first axis 40 .

[0056] The rear duct 21 is an outlet duct for the second fluid, i.e. the cold gas in the example in question. The outlet duct comprises a rear orifice flange 17 to allow fastening to a rear connection flange of a rear connection channel 31 having an outlet for the second fluid. A seal, such as an O-ring seal or a compression seal, is placed between the rear orifice flange 17 and the rear connection flange 31.

[0057] The housing 2 includes a tubular wall 51 including a front opening configured to allow the rear header 12 and the tube bundle 13 to pass through the housing 2 during assembly or removal of the removable tube group 1 relative to the housing 2 .

[0058] This allows the removable tube set 1 to slide in and relative to the housing 2 .

[0059] The front header 11 includes a front header flange 22. The front header flange 22 is a single piece or assembled by welding with the front housing 18 or with the front tubular plate 14 to allow the front header 11 to be fastened to the front flange 56 of the housing.

[0060] The front header flange 22 has substantially the same inner diameter as the front flange 56 of the housing.

[0061] A front seal is interposed between the front flange 56 of the housing and the front manifold flange 22 so as to allow sealing with respect to the first fluid.

[0062] The rear header 12 includes a converging profile that converges over at least a portion between the rear tubular plate 15 and the rear aperture as proceeding along the first longitudinal axis 40 in a direction from the front portion toward the rear portion.

[0063] In the example involved, the rear housing 20 is conical.

[0064] The front header 11 comprises a gripping unit 60 for the passage of a lifting tool which allows the removal of the removable tube set 1 from the housing 2 .

[0065] The exchanger 100 has no flange for clamping the rear header 12 relative to the housing 2 .

[0066] [ Figure 2 ] indicates that [ Figure 1 In this intermediate removal position, the tube set 1 has already partially slid relative to the housing 2.

[0067] To fit the tube set 1 in the housing 2 , the tube set 1 is slid along the first longitudinal axis 40 from the front part to the rear part until the rear aperture flange 17 abuts the rear connection flange 31 .

[0068] In order to make the tube set 1 integral with the housing 2, each flange as described above is integral with the flange on which it is positioned, by means of a nut or any other type of connection means. A seal, such as an O-ring seal or a compression seal, is placed between these two flanges in order to prevent leakage of the second fluid relative to the atmosphere or of the first fluid from leaking outside the housing 2.

[0069] More specifically, the following are fastened together:

[0070] - the front manifold flange 22 is fastened to the front housing flange 56;

[0071] - the rear header flange 17 is fastened to the rear connection flange 31;

[0072] The front duct flange 16 is fastened to the front connecting flange 30 .

[0073] Finally, sealing means 70 , 72 , 73 are added between the rear header 12 and the rear opening of the housing 2 with respect to the first fluid.

[0074] To remove the tube set 1 from the housing 2, each flange is first separated from the flange against which it is positioned, and then the sealing device 70 is removed. Finally, the tube set 1 is slid relative to the housing 2 so as to be taken out of the housing 2.

[0075] [ Figure 3 ] represents a first embodiment of the sealing device 70, 72.

[0076] The sealing device comprises a lining 72, which is notably fitted to be clamped between the rear tubular plate 15 and the inner wall of the housing 2. The sealing device also comprises a clamping ring 70, which is integrally fitted with the shoulder 50 of the housing 2.

[0077] The nut 71 enables the clamping ring 70 to be integrated with the housing 2 .

[0078] [ Figure 4 ] represents a second embodiment of the sealing device 70, 72, 73.

[0079] The sealing device includes a bellows 70 fastened to the housing 2 by a nut 71, wherein a first O-ring seal 72 is placed between the housing 2 and the bellows 70, and the bellows 70 is also fastened to the rear manifold 12 by a nut 74, wherein a second seal 73, especially an O-ring seal, is placed between the bellows 70 and the rear manifold 12.

[0080] [ Figure 5 ] represents a third embodiment of the sealing device 70, 73.

[0081] The sealing device includes a bellows 70 which is a single piece or assembled by welding with the housing 2 , and the bellows 70 is also fastened to the rear manifold 12 by a nut 74 , wherein a second seal 73 , in particular an O-ring seal, is placed between the bellows 70 and the rear manifold 12 .

Claims

1. A shell and tube heat exchanger (100) extending along a first longitudinal axis (40) between a front portion and a rear portion, the exchanger (100) comprising: a housing (2) defining an internal volume designed to allow a first fluid, in particular a cooling fluid, to pass through it; as well as a removable tube set (1) extending along the first longitudinal axis (40) and defining a circuit for the circulation of a second fluid, the removable tube set (1) comprising: - a front header (11) defining a front chamber for the second fluid, the front header (11) comprising a front shell (18), a front base (19) which is a single piece or assembled by welding with the front shell (18), a front opening for the second fluid to enter or leave, a front duct (10) which opens to the front opening and is a single piece or assembled by welding with the front shell (18), and a front tubular plate (14) which is integral with the front shell (18); a rear header (12) defining a rear chamber for the second fluid, the rear header (12) comprising a rear shell (20), a rear orifice for the second fluid to enter or leave, a rear duct (21) leading to the rear orifice and being in one piece or assembled by welding with the rear shell (20), and a rear tubular plate (15) integral with the rear shell (20); a tube bundle (13) comprising a set of tubes for the passage of the second fluid and arranged so that the second fluid passes through the housing (2) only once between the front orifice and the rear orifice, The front tubular plate (14) is a single piece or is assembled by welding with the front shell (18), the rear tubular plate (15) is a single piece or is assembled by welding with the rear shell (20), and the tube bundle (13) is a single piece or is assembled by welding with the front tubular plate (14) and the rear tubular plate (15).

2. Exchanger (100) according to the preceding claim, the tube group (1) being designed to be removable from the housing (2), the group (1) being in particular fitted to slide relative to the housing (2), for example via the front part.

3. The exchanger (100) as claimed in one of the preceding claims, the front manifold (11) comprises a front manifold flange (22), which is in particular a one-piece structure or is assembled by welding with the front outer shell (18) or with the front tubular plate (14) so ​​as to allow the front manifold (11) to be fastened to the front flange (56) of the shell, and the front manifold flange (22) in particular has an inner diameter substantially the same as that of the front flange (56) of the shell.

4. The exchanger (100) according to the preceding claim, comprising a front seal interposed between the front flange (56) of the casing and the front header flange (22) so as to allow sealing relative to the first fluid.

5. The exchanger (100) as described in one of the preceding claims, the rear header (12) includes a converging profile which converges on at least a portion of the first longitudinal axis (40) when moving along the first longitudinal axis (40) in the direction from the front portion toward the rear portion, the portion being in particular between the rear tubular plate (15) and the rear orifice, the rear shell (20) being in particular conical.

6. The exchanger (100) according to one of the preceding claims, the front header (11) comprising a gripping unit (60) for the passage of a lifting tool allowing the removal of the removable tube group (1) from the housing (2).

7. Exchanger (100) according to one of the preceding claims, comprising means (70, 72, 73) for sealing relative to the first fluid, the sealing means being positioned in particular between the rear header (12) and the rear opening of the casing (2).

8. The exchanger (100) as claimed in the preceding claim, the sealing device comprising a lining (72), which is particularly assembled to be clamped between the rear tubular plate (15) and the inner wall of the shell (2), and the sealing device particularly comprises a clamping ring (70), which is integrally assembled with the shoulder (50) of the shell (2).

9. The exchanger (100) as described in claim 7, wherein the sealing device includes a bellows (70) fastened to the shell (2), wherein a first O-ring seal (72) is placed between the shell (2) and these bellows (70), and these bellows (70) are also fastened to the rear manifold (12), wherein a second seal (73), in particular an O-ring seal, is placed between these bellows (70) and the rear manifold (12).

10. The exchanger (100) as claimed in claim 7, wherein the sealing device comprises bellows (70) which are one-piece or assembled by welding with the shell (2), and these bellows (70) are also screwed on the rear manifold (12), wherein a second seal (73), in particular an O-ring seal, is placed between these bellows (70) and the rear manifold (12).

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