CN212645443U

CN212645443U - Tubular assembly

Info

Publication number: CN212645443U
Application number: CN202020189819.8U
Authority: CN
Inventors: M·J·凯特
Original assignee: Murray James Kate
Current assignee: Murray James Kate
Priority date: 2019-02-20
Filing date: 2020-02-20
Publication date: 2021-03-02
Anticipated expiration: 2030-02-20
Also published as: CN111595182A

Abstract

The present invention relates to a tubular assembly (1), said tubular assembly (1) having an outer tubular member (10) with an outer wall (12) enclosing an outer cavity (14). The inner tubular member (20) has an inner wall (22) surrounding an inner lumen (24). The inner tubular member (20) is disposed within the outer cavity (14), and the outer wall (12) and the inner wall (22) are joined in a compression-shape fit in the section (S1) such that the outer wall (12) at least partially defines an outer flow path (30) relative to the inner cavity (24). The above-described tubular assembly significantly reduces costs and simplifies the process compared to the prior art.

Description

Tubular assembly

Technical Field

The present invention relates to a tubular assembly having at least two separate flow paths.

Background

Tubular assemblies having at least two separate flow paths are being used in a variety of applications, for example as conduits or heat exchangers requiring strict separation of the transported substances.

Particularly in the field of heat exchangers, the general function of which is well known in the art, it is often desirable that the individual flow paths have large adjacent surface areas and/or are close (in close proximity) to each other to allow for optimal heat transfer between the fluids transported in the respective flow paths.

To this end, the prior art suggests the use of flow paths that engage each other in a helical or spiral fashion and use a welded or brazed connection between them to provide good heat transfer and achieve a strong, durable and sealed connection between the flow paths.

US2008/0000616a1 may be mentioned as an example of such a prior art heat exchanger and corresponding manufacturing method. Referring to fig. 3 and 4 of this document, the tubular portion forming the inner catheter 1 comprises helical corrugations 48, which helical corrugations 48 together with the outer sheath 42 form the second catheter 44. In order to achieve a sealed connection between the sleeve and the corrugations, the interface between the two parts comprises an additional layer 47 of highly conductive material, said additional layer 47 being used to establish a soldered connection.

Those skilled in the art will appreciate that the requirement to braze or weld or solder the components together (depending on the material pairing) is not only complex and laborious, but can also compromise material properties due to the heat introduced. Damage and/or failure due to embrittlement of the material or an unfavourable reduction in the strength of the material due to recrystallization or the like may then occur.

The skilled person will appreciate that the coiled catheter on the inner tube shown in US2008/0000616a1 needs to be manufactured in a separate operation. An example of a corresponding prior art method can be found in EP0664862B1, which discloses the use of a mandrel on which a smooth tube is mounted. The helical corrugation on the tube is applied by means of a pair of forming wheels which are pressed against the sleeve of the tube and against the mandrel.

The informed reader will recognize that it is desirable to simplify the manufacture of heat exchangers as described above and/or to provide heat exchangers with better characteristics in terms of heat transfer, strength and durability. It is an object of the present invention to provide a tubular assembly and/or a heat exchanger and/or a method of manufacturing a tubular assembly and/or a heat exchanger which will overcome or ameliorate at least one of the disadvantages known in tubular assemblies and/or heat exchangers and/or methods of manufacturing thereof or which will at least provide a useful alternative.

Other objects of the invention will become apparent from the following description, given by way of example only.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that prior art forms part of the common general knowledge in any country.

SUMMERY OF THE UTILITY MODEL

According to an aspect of the present invention, there is provided a tubular assembly, comprising

An outer tubular member having an outer wall at least partially surrounding an outer lumen;

an inner tubular member having an inner wall at least partially surrounding an inner lumen, the inner tubular member being at least partially disposed within the outer lumen;

wherein the outer wall and the inner wall are at least sectionally joined with a compression-shape fit such that the outer wall at least partially defines an outer flow path relative to the inner cavity.

Preferably, the outer wall exhibits a first longitudinal undulating pattern having a first amplitude, wherein the outer flow path is formed between the outer wall and the raised portion of the inner wall.

Preferably, the first longitudinal relief pattern extends helically around the lumen.

Preferably, the inner wall exhibits a second longitudinal relief pattern having a second amplitude smaller than the above-mentioned first amplitude, wherein the first longitudinal relief pattern and the second longitudinal relief pattern have corresponding form-fitting properties in view of a compressive form-fit between the outer wall and the inner wall.

Preferably, the compression shape fit between the outer wall and the inner wall forms a compression seal between the outer wall and the inner wall.

Preferably, the outer flow path fluidly connects the outer inlet to the outer outlet, and the inner chamber fluidly connects the inner inlet to the inner outlet to form the inner flow path.

Preferably, the outer wall is joined to the inner wall at respective first and second outer ends of the outer tubular member.

Preferably, the tubular assembly is a heat exchanger.

Preferably, the outer tube and the inner tubular member are substantially cylindrical tubes.

Preferably, the outer wall and the inner wall are made of a metallic material, preferably different metals.

According to another aspect of the present invention, provide

A method of manufacturing a tubular assembly having an outer flow path and an inner flow path, the inner flow path being fluidly separate from the outer flow path, the method comprising the steps of

S1: disposing an inner tubular member having an inner wall at least partially defining an inner flow path at least partially within an outer tubular member having an outer wall, thereby creating a preform;

s2: deforming the outer wall along the first longitudinal undulation pattern to form a compressive shape fit between the outer wall and the inner wall such that the respective raised portions of the outer wall at least partially define the outer flow path.

Preferably, in step S1, the dimensions of the inner and outer tubular members are selected such that the inner and outer walls are at a distance d₀And (4) separating.

Preferably, step S2 includes the following sub-steps

S2 a: positioning at least one forming tool in contact with the outer surface of the outer wall;

s2 b: the forming tool is forced against the outer wall while applying relative motion between the forming tool and the preform to deform the outer wall along a first longitudinal relief pattern having a first amplitude.

Preferably, in step S2b, the forming tool further deforms the inner wall according to a second longitudinal relief pattern having a second amplitude, wherein the first and second longitudinal relief patterns are similar, and wherein the second amplitude is smaller than the first amplitude.

Preferably, the first longitudinal undulating pattern and the second longitudinal undulating pattern extend helically along the outer wall.

Preferably, in step S2b, the forming tool is forced against the outer wall such that a wave of material is formed from the outer wall and moves in the direction of the longitudinal axis of the outer tubular member to form a raised portion of the outer wall.

Preferably, the material wave is formed substantially without reducing the thickness of the outer wall, thereby reducing the longitudinal extension of the outer tubular member in step S2.

Preferably, in step S2, at least the inner tubular member is supported in the longitudinal direction.

Preferably, the forming tool comprises at least one pair of rollers, more preferably three or more rollers.

Drawings

Fig. 1 shows a cross-sectional view of a tubular assembly according to an embodiment of the invention, taken along the longitudinal axis X of the tubular assembly 1.

Fig. 2 shows a partially cut-away three-dimensional view of an embodiment of the tubular assembly 1 according to the invention.

Fig. 3 shows a preform of a tubular assembly assembled during a method of manufacturing a tubular assembly according to an embodiment of the invention.

Fig. 4 shows steps performed during a method of manufacturing a tubular assembly according to an embodiment of the invention.

Fig. 5 shows a cross-sectional view of the tubular assembly according to an embodiment of the invention, taken along the longitudinal axis X of the tubular assembly 1.

Detailed Description

Fig. 1 shows a cross-sectional view of a tubular assembly 1 according to the invention, taken along a longitudinal axis X. In this figure the tubular assembly 1 is a heat exchanger, but in other embodiments the tubular assembly may be used to transport fluid in two separate flow paths for purposes other than heat exchange. The tubular assembly 1 comprises an outer tubular member 10, said outer tubular member 10 having an outer wall 12 at least partially surrounding an outer lumen 14.

Further, the tubular assembly 1 comprises an inner tubular member 20, said inner tubular member 20 having an inner wall 22 at least partially surrounding an inner lumen 24. The inner tubular member 20 is at least partially arranged within the outer lumen 14, as can best be seen in fig. 2, which fig. 2 contains a partially cut-away three-dimensional view of an embodiment of the tubular assembly 1 according to the present invention.

In a preferred embodiment of the invention, the outer wall 12 and the inner wall 22 comprise or are made of a metallic material, in particular different (dissimilar) metals. A corresponding embodiment includes a tubular assembly 1 in which the outer wall 12 comprises a strong material, such as carbon steel or stainless steel, or a material with enhanced corrosion resistance, such as titanium or aluminum, and the inner wall 22 comprises a material with excellent heat transfer properties, such as copper, a copper/nickel alloy, or titanium. Other material pairings may be envisaged for specific purposes, and the present invention eliminates most of the limitations of the prior art for material pairings, as shown below.

As will be appreciated, in the embodiment shown in fig. 1 and 2, the

tubular members

10, 20 have a substantially circular cross-section and their overall shape may be referred to as substantially cylindrical. In other embodiments, the

tubular members

10, 20 may each exhibit other cross-sectional shapes, such as an elliptical or polygonal cross-section.

Turning again to fig. 1, the outer wall 12 and the inner wall 22 are in a compressed form fit at least in section S1. In some embodiments, the compressed shape fit forms a compression seal between the outer wall 12 and the inner wall 22, thereby subdividing the outer chamber 14 into portions that are fluidly connected and thereby form the outer flow path 30. In other embodiments, the compression form fit may not form a compression seal, but may simply be sufficiently tight to direct a substantial portion of the fluid transferred between the outer wall 12 and the inner wall 22 along the outer flow path 30.

According to the present invention, no welding or brazing is required between the outer wall 12 and the inner wall 22 to define the outer flow path 30. As will be appreciated by the skilled person, this is highly desirable as it removes design constraints on the material pairing of the tubular assembly. In the prior art, certain material pairs (material pairs) comprising, for example, stainless steel, nickel, copper, titanium, aluminum and/or certain alloys thereof, may be advantageous for heat transfer and robustness or corrosion resistance, but as a result are difficult to weld or not weldable at all. The present invention overcomes this disadvantage because the compressed form fit between the outer wall 12 and the inner wall 22 forms the outer flow path 30 without requiring any additional joining and/or sealing processes.

To achieve a compressive form fit, in the illustrated embodiment, the outer wall 12 exhibits a first longitudinal undulating (wavy) pattern in which the raised portions 36 of material are formed at a first amplitude a1 at a wavelength w 1. The inner wall 22 includes a second longitudinal undulating (wavy) pattern in which the raised portions 38 are formed with a second amplitude a2 that is less than the first amplitude a 1. As a property of the compressive form fit, the first longitudinal relief pattern and the second longitudinal relief pattern have the same wavelength w1, but the outer wall 12 and the inner wall 22 may have other corresponding form fit features in addition to or instead of this. For example, if the first and second longitudinal relief patterns comprise parallel reliefs extending parallel to the longitudinal axis X of the tubular assembly 1, the corresponding shape matching characteristic of the first and second longitudinal relief patterns will be the corresponding distance between the parallel reliefs along the perimeter of the outer and

inner walls

12, 22.

The compressive form fit may be achieved by simultaneous deformation of the outer wall 12 and the inner wall 22, as will be described in more detail further below.

The corresponding form fit characteristics are selected such that the outer flow path 30 is formed between the raised

portions

36, 38 between the outer wall 12 and the inner wall 22, respectively. In the embodiment shown in fig. 1 and 2, the groove portions of the first longitudinal relief pattern and the second longitudinal relief pattern form a section S1 engaged in a compression shape fit. Meanwhile, the peaks of the first longitudinal undulation pattern and the second longitudinal undulation pattern form the openings of the flow paths 30. Thus, as understood by the skilled person, the height of the outer flow path 30 corresponds to the difference between the first amplitude a1 and the second amplitude a2 of the

body portions

36, 38, respectively.

The skilled person will clearly see that the difference between the first amplitude a1 and the second amplitude a2 may be selected depending on requirements considering the cross section of the outer flow path 30 and/or considering the required compression between the outer wall 12 and the inner wall 22.

In the embodiment shown in fig. 1 and 2, the first longitudinal relief pattern and the second longitudinal relief pattern are helically relief (undulating) patterns such that the flow path 30 extends helically along the lumen 24 and around the lumen 24.

Although the relief pattern shown in fig. 1 is shown as having an angled shape, the relief pattern in other embodiments has a more curved shape, as shown in fig. 5. In fig. 1 and 5, like reference numerals are used to indicate like features.

In the heat exchanger application shown in fig. 1, 2 and 5, the outer flow path 30 fluidly connects the outer inlet 16 with the outer outlet 18, wherein the first fluid is transported along the outer flow path 30, as indicated by arrows F1, F2 in fig. 1. Similarly, the inner cavity 24 fluidly connects the inner inlet 26 to the inner outlet 28 to form an inner flow path 40, the flow of fluid being represented by arrows F3, F4.

To achieve a fluid seal in heat exchanger applications, the outer wall 12 may be joined to the inner wall 22 at respective first and second outer ends 15, 17 of the outer tubular member 10. Suitable joining processes include welding, brazing, soldering, gluing, crimping, to name a few.

Hereinafter, the tubular assembly 1 described in fig. 1, 2 and 5 will be described in more detail in view of a corresponding method of manufacturing a tubular assembly 1 having an outer flow path 30 and an inner flow path 40 fluidly separated from the outer flow path 30. In this context, like reference numerals are used to denote like features.

In a first step S1, schematically illustrated in fig. 3, the method of the present invention comprises arranging the inner tubular member 20 at least partially within the outer tubular member 10, thereby forming the preform 50. The inner wall 22 of the inner tubular member 20 comprises a volume that at least partially forms the inner flow path 40 in a subsequent step.

At this stage, the outer tubular member 10 of the illustrated embodiment is of an outer radius R_oAnd the wall thickness t of the outer wall 12_oOf the substantially cylindrical member. Similarly, the inner tubular member 20 is of inner radius R_iAnd the wall thickness t of the inner wall 22_iOf the substantially cylindrical member.

Although the depicted embodiment of the outer and inner

tubular members

12, 22 is cylindrical, other embodiments may exhibit other shapes and cross-sections, such as an elliptical or rectangular cross-section and/or a cross-section that is variable along a first axis X that corresponds to the longitudinal axis of the outer or inner

tubular members

10, 20.

The dimensions of the inner and outer

tubular members

10, 20, in particular the outer radius Ro and the inner radius Ri, are selected such that the inner wall 22 and the outer wall 12 are at a distance d along the circumference of the inner tubular member 10₀And (4) separating. In the embodiment depicted, the preform is held in place in this configuration by a first support 60 and a second support 62.

Those skilled in the art will appreciate that in the state shown in FIG. 3, the distance d is defined by₀The defined annular space around the inner wall 22 corresponds to the portion of the outer chamber 14 not occupied by the inner tubular member 20. Furthermore, it is apparent that in the construction of the preform 50, the distance d is defined by₀The defined annular space and the inner cavity 24 may be said to form a preliminary first flow path and a second flow path.

In a next step S2 of the method according to the invention, as shown in fig. 4, the outer wall 12 is deformed to form a compressive form fit between the outer wall 12 and the inner wall 22 along the first longitudinal undulating pattern such that the corresponding raised portions (humps) 36 of the outer wall 12 define the outer flow path 30.

Details regarding the raised portion 36 of the outer wall 12, such as the first amplitude a1, implemented along the first longitudinal undulating pattern, have been described above in connection with fig. 1 and 2, which show a tubular assembly manufactured using the method according to the present description of the invention. In view of fig. 4, those skilled in the art will appreciate that the deformation of the outer wall 12 may be accomplished by means of a forming tool 70, which in the depicted embodiment is a pair of opposing rollers, to pass through an offset d_LSpaced apart in the longitudinal direction X to form a helical relief pattern. In other embodiments, more than one roller distributed along the perimeter of the outer wall 12 may be used as the forming tool 70, or only one roller. However, it has been found that the method according to the invention is particularly advantageous when three or more rollers distributed along the circumference of the outer wall 12 are used as forming tool 70Is effective.

In a preferred embodiment, to deform the outer wall 12 and the inner wall 22, in sub-step S2a, the forming tool 70 is positioned in contact with the outer surface of the outer wall 12. Fig. 4 shows the forming tool 70 at a later, early stage of deforming the outer wall 12, which is why the deformation of the outer wall 12 is not shown in the area other than below the forming tool 70. Furthermore, those skilled in the art will recognize that in the illustrated embodiment, not only the outer wall 12 is deformed by the forming tool 70, but also the inner wall 22. Although it is possible to create a compressive form fit between the outer wall 12 and the inner wall 22 by deforming the outer wall 12 alone, it has been found that for a reliable fluid-tight compressive form fit, it is preferable to deform the outer wall 12 to an extent such that the pressure applied by the forming tool 70 is also transmitted to the inner wall 22 to deform the inner wall 22 together with the outer wall 12. This deformation of the inner wall 22 follows the deformation of the outer wall 12 in shape and pattern, as both deformations are achieved in a single step by the forming tool 70. Thus, the inner wall 22 is deformed according to a second longitudinal relief pattern having a second amplitude a2, wherein the first and second longitudinal relief patterns are similar, and wherein the second amplitude a2 is smaller than the first amplitude a 1.

In sub-step S2b, the forming tool 70 is further pressed against the outer wall 12 while the relative movement between the forming tool 70 and the preform 50 is applied to deform the outer wall 12 along the first longitudinal relief pattern.

The first component of this relative movement is indicated by the arrow D1, the arrow D1 pointing in a direction substantially parallel to the longitudinal axis X. The second component of the relative movement extends in a direction perpendicular to the first member and along the perimeter of the outer wall 12 such that the relative movement generated between the forming tool 70 and the preform 50 extends along a helical path H, indicated by the dashed line in fig. 4. Therefore, in the present embodiment, the first longitudinal undulation pattern and the second longitudinal undulation pattern extend spirally along the outer wall 12.

In other embodiments of the invention, the relief pattern produced may comprise other shapes, such as parallel reliefs extending parallel to the longitudinal axis X of the preform 5. In such embodiments, the outer flow path 30 includes a plurality of individual flow paths extending parallel to the first flow path 40.

In certain embodiments, it is contemplated to use two or more forming tools 70, the forming tools 70 being spaced apart along the longitudinal axis X of the

tubular members

10, 20, each forming tool 70 acting on only a portion of the overall resulting deformation of the outer portion 12 and the inner wall 22. This may be advantageous in cases where the deformation amplitude a1 of the outer wall 12 is relatively large and/or when very stiff materials are used for the outer wall 12 and/or the inner wall 22. In this case, the relief pattern is not easily completed by a single forming tool 70.

As will be appreciated by the skilled person, during the generation of the first longitudinal relief pattern in step S2b, the relative movement between the forming tool 70 and the preform 50, and in particular the longitudinal component thereof, indicated by arrow D1 in fig. 4, forms a wave of material on the outer wall 12 and moves it in the direction of the longitudinal axis X of the outer tubular member 10. This material then forms the raised portion 36 of the outer wall 12 that forms part of the outer flow path 30. Preferably, the wave of material is formed without substantially reducing the wall thickness of the outer wall 12. As a result, when the first amplitude a1 is greater than the second amplitude a2, the longitudinal extension of the outer tubular member 10 along the longitudinal axis X is reduced in step S2.

By moving the amount of material in the direction of the longitudinal axis X, the height of the body portion 36, and thus the cross-section of the outer flow path 30, can be controlled.

In step S2, where at least the outer wall 12 is deformed according to the first longitudinal relief pattern, it may be necessary to further support the preform 50 in addition to the first and

second clamps

60, 62.

Fig. 1 depicts an embodiment of a tubular assembly 1 manufactured according to the method of the present invention. Thus, the skilled person will appreciate that in addition to the forming step shown in fig. 4, the method may further comprise machining the outer tubular member 10 to include an inlet 16 to the outer flow path 30 and an outlet 18 from the outer flow path, and may further comprise sealing the outer wall 12 against the inner wall 22 at the first and second outer ends 15, 17 of the outer tubular member 10 by a suitable process, such as welding, brazing, soldering (soldering), gluing or crimping.

Those skilled in the art will recognize that the method according to the present invention provides several advantages compared to the prior art. This approach broadly overcomes the need to apply a joining process such as welding, brazing, soldering or gluing to create a bond between the outer flow path 30 and the inner flow path 40. In addition, the method of the present invention eliminates the need to use a mandrel to form the first longitudinal undulating pattern on the outer tubular member 10, which means that the equipment required to manufacture the tubular assembly 1 according to the present invention is significantly reduced compared to known tubular assemblies. This not only reduces costs, but also simplifies and speeds up the manufacturing process.

As a synergistic effect, the tubular assembly 1 according to the invention, although saving weight and material because it has no filler metal for the weld, actually increases efficiency when used as a heat exchanger, since the areas of the outer wall 12 and the inner wall 22 joined in a compression-shape fit exhibit excellent heat transfer characteristics.

As another advantage, the inventive method of manufacturing the tubular assembly 1 allows a wider range of material pairings for the outer flow path 30 and the inner flow path 40 than methods known in the prior art, since the outer wall 12 and the inner wall 22 are not heated or even liquefied during the manufacturing process as in the prior art. Although different metal pairings for the outer wall 12 and the inner wall 22 are disclosed above, in a particular application of the tubular assembly 1 according to the invention, it may even be desirable to combine a metallic material for the outer wall 12 or the inner wall 22 with a non-metallic material, e.g. a plastic material, for the respective other inner wall 12 or the outer wall 12. The present invention enables the skilled person to use various material pairings and tailor the tubular assembly 1 according to his needs, provided that these materials exhibit suitable material properties in terms of formability.

Although embodiments of the present invention have been described as having particular application to heat exchangers, those skilled in the art will appreciate that alternative embodiments may be used with other types of tubular assemblies and/or conduits.

Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise," "comprising," and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is, in a sense of "including, but not limited to.

In the foregoing specification, reference has been made to specific components or integers of the invention having known equivalents, which equivalents are herein incorporated as if individually set forth.

Although the present invention has been described by way of example and with reference to possible embodiments thereof, it is to be understood that modifications or improvements may be made thereto without departing from the spirit or scope of the appended claims.

Claims

1. Tubular assembly (1), characterized in that it comprises:

an outer tubular member (10) having an outer wall (12) at least partially enclosing an outer lumen (14);

an inner tubular member (20) having an inner wall (22) at least partially surrounding an inner lumen (24), the inner tubular member (20) being at least partially disposed within the outer lumen (14);

wherein the outer wall (12) and the inner wall (22) are engaged in a compression-shape fit at least in a section (S1) such that the outer wall (12) at least partially defines an outer flow path (30) relative to the inner cavity (24).

2. A tubular assembly (1) according to claim 1, wherein the outer wall (12) exhibits a first longitudinal undulating pattern having a first amplitude (a1), and wherein the outer flow path (30) is formed between the inner wall (22) and the raised portion (36, 38) of the outer wall (12).

3. A tubular component (1) according to claim 2, characterized in that said first longitudinal relief pattern extends helically around said lumen (24).

4. A tubular component (1) according to claim 2, characterized in that the inner wall (22) presents a second longitudinal relief pattern having a second amplitude smaller than the first amplitude, wherein the first and second longitudinal relief patterns have respective shape-fitting properties in view of a compressive shape-fitting between the outer wall (12) and the inner wall (22).

5. A tubular assembly (1) according to any of claims 1 to 4, characterized in that the compression shape fit between the outer wall (12) and the inner wall (22) forms a compression seal between the outer wall (12) and the inner wall (22).

6. A tubular assembly (1) according to any of claims 1-4, characterized in that the outer flow path (30) fluidly connects the outer inlet (16) with the outer outlet (18) and the inner lumen (24) fluidly connects the inner inlet (26) with the inner outlet (28) to form the inner flow path (40).

7. A tubular assembly (1) according to any one of claims 1-4, characterized in that the outer wall (12) is joined to the inner wall (22) at respective first (15) and second (17) outer ends of the outer tubular member (10).

8. A tubular component (1) according to any of the claims 1 to 4, characterized in that the tubular component (1) is a heat exchanger.

9. A tubular assembly (1) according to any of claims 1-4, characterized in that the outer tubular member (10) and the inner tubular member (20) are substantially cylindrical tubes.

10. A tubular component (1) according to any of claims 1 to 4, characterized in that the outer wall (12) and the inner wall (22) are made of a metallic material.

11. A tubular component (1) according to claim 10, characterized in that said outer wall (12) and said inner wall (22) are made of different metals.