GB2376432A - Method of making a heat exchanger tube, and heat exchanger tube made thereby - Google Patents

Method of making a heat exchanger tube, and heat exchanger tube made thereby Download PDF

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Publication number
GB2376432A
GB2376432A GB0125828A GB0125828A GB2376432A GB 2376432 A GB2376432 A GB 2376432A GB 0125828 A GB0125828 A GB 0125828A GB 0125828 A GB0125828 A GB 0125828A GB 2376432 A GB2376432 A GB 2376432A
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GB
United Kingdom
Prior art keywords
extended surface
heat exchanger
tube
surface member
exchanger tube
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB0125828A
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GB0125828D0 (en
Inventor
David Bland Pierce
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
APPLIED SYSTEMS MAN Ltd
Original Assignee
APPLIED SYSTEMS MAN Ltd
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Filing date
Publication date
Application filed by APPLIED SYSTEMS MAN Ltd filed Critical APPLIED SYSTEMS MAN Ltd
Publication of GB0125828D0 publication Critical patent/GB0125828D0/en
Publication of GB2376432A publication Critical patent/GB2376432A/en
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
    • F28F13/06—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by affecting the pattern of flow of the heat-exchange media
    • F28F13/12—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by affecting the pattern of flow of the heat-exchange media by creating turbulence, e.g. by stirring, by increasing the force of circulation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
    • B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
    • B21C37/15—Making tubes of special shape; Making tube fittings
    • B21C37/22—Making finned or ribbed tubes by fixing strip or like material to tubes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D39/00—Application of procedures in order to connect objects or parts, e.g. coating with sheet metal otherwise than by plating; Tube expanders
    • B21D39/08—Tube expanders
    • B21D39/20—Tube expanders with mandrels, e.g. expandable
    • B21D39/203—Tube expanders with mandrels, e.g. expandable expandable by fluid or elastic material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D53/00—Making other particular articles
    • B21D53/02—Making other particular articles heat exchangers or parts thereof, e.g. radiators, condensers fins, headers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/40—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only inside the tubular element

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Geometry (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

Abstract

This invention relates to a method of making a heat exchanger tube 12, and in particular to a method of making a heat exchanger tube having at least one internal extended surface member 10, the method comprising the steps of: i selecting a heat exchanger tube, ii manufacturing an extended surface member, the extended surface member having a bore with a predetermined cross-sectional dimension, iii locating a resilient member 30 within the bore, the resilient member when in its fully relaxed state having a cross-sectional dimension greater than the predetermined cross-sectional dimension, iv stretching the resilient member in the longitudinal direction, v inserting the extended surface member into the tube, and v allowing the resilient member to relax. The invention also relates to a heat exchanger tube manufactured by the method described.

Description

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METHOD OF MAKING A HEAT EXCHANGER TUBE, AND HEAT EXCHANGER TUBE MADE THEREBY FIELD OF THE INVENTION This invention relates to a method of making a heat exchanger tube, and to a heat exchanger tube made by that method. The invention relates in particular to a method of making a heat exchanger tube having at least one internal extended surface member.
Whilst the method according to the invention can be used to make heat exchanger tubes in different sizes and suited to various applications, the heat exchanger tubes so made are expected to find their greatest utility for the larger sizes of heat exchanger used in refrigeration units, such as the refrigeration units of container ships. Whilst much of the following description relates to such application, the use of the invention for other applications in not thereby excluded.
BACKGROUND OF THE INVENTION Often it is necessary to cool or heat a working fluid, and it is known for this purpose to use a heat exchanger. Heat exchangers usually comprise one or more metallic tubes mounted between two tube plates, though it is known to use U-shaped tubes with each tube connected at opposite ends to a single tube plate.
In refrigeration units, the working fluid flows within the tubes and in one part of the cycle (the evaporator) it evaporates from a liquid into a gas, taking up heat from the tube and from the surrounding environment which is desired to be cooled. In another part of the cycle (the condenser) the gas condenses into a liquid and gives up heat to the tube and to the surrounding environment.
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Many heat exchanger tubes utilise extended surface members which are designed to increase the rate of thermal transfer by increasing the effective surface area between the tube and the working fluid, and/or between the tube and the surrounding environment. In the condenser part of the cycle of a refrigeration unit it is known to use external extended surface members in the form of outwardly directed fins or plates, and in the evaporator part of the cycle it is known to use internal extended surface members (i. e. extended surface members located within the tube (s).
DESCRIPTION OF THE PRIOR ART One form of heat exchanger tube having an internal extended surface member is assembled from a tube and an initially separate extended surface member designed to be a sliding fit within the tube. The extended surface member is of heat-conductive metallic material, and when viewed in longitudinal cross section comprises a central core from which a number of radial fins project; the extended surface member may be an aluminium extrusion for example. Following insertion of the extended surface member into the tube the tube is passed through a die which compresses the tube so that the inside surface of the tube wall is forced against the peripheral ends of the fins. The engagement between the ends of the fins and the tube wall must be sufficient to allow heat to be transferred therebetween, so that the fins can communicate heat from the tube wall to the working fluid, and vice versa.
The length of the extended surface member will typically closely match the length of the tube, i. e. the tube will have an internal extended surface member for all (or substantially all) of its length.
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In some cases, the central core of the extended surface member is hollow, and in such cases the hollow core will usually be plugged or otherwise filled so that the working fluid does not flow therealong, but rather flows along the channels created between the fins and the tube wall.
Such heat exchanger tubes with internal extended surface members are"made to measure", i. e. they are manufactured to be of a particular size so as to fit a particular heat exchanger, and to be of a chosen material (or materials) to provide the desired heat exchange characteristics.
It is known for a heat exchanger tube to fail. The failure might be partial, for example due to erosion, corrosion or the build-up of debris or scale, causing a decrease in the heat transfer characteristics of the tube. Alternatively, the failure might be total, caused for example by damage of the tube, or by erosion and/or corrosion causing the tube to leak. In both cases, the failure can require the tube to be repaired or replaced.
Whilst it is possible mechanically to remove an extended surface member from inside a compressed tube, the introduction of a new or replacement extended surface member into a pre-compressed tube is not possible, i. e. the tube cannot have the desired heat exchange characteristics unless the tube is compressed into thermal engagement with the extended surface member. Accordingly, the repair of an existing compressed tube is seldom if ever possible, and instead a new replacement tube has to be manufactured to suit the particular heat exchanger. The replacement tube can typically take three months to manufacture, supply and fit.
If the failed heat exchanger tube is. that of a container ship for example, it is usually necessary to repair or replace it on the ship, since a heat exchanger will typically be located in a position from which it is not
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practicable to remove it for off-site repair. Thus, in order to remove a heat exchanger from a ship it is typical to require the prior removal of a part of one or more decks, or a part of the hull, which will clearly only be undertaken in exceptional circumstances.
Therefore, during the three months prior to fitment of the new heat exchanger tube, the container ship may need to be taken out of service. Clearly, keeping a container ship out of service for this length of time is very expensive, but it is not always possible to predict when a heat exchanger tube is going to need replacement sufficiently far in advance so that the tube is ready when required.
An alternative design of internal extended surface member is in the form of a length of relatively thin wire, wound into a convoluted but generally helical form. Such wound wires are often known as"turbulators"since when fitted into a tube they induce turbulence into a fluid flowing therethrough. Such extended surface members do not require compression of the tube, and so can be removed and replaced relatively easily. However, whilst they are effective at introducing turbulence into the fluid within the tube, they are not very effective at transferring heat to and from the tube, since the area of the wire in engagement with the tube wall is small, and is not adapted to good thermal transfer.
Accordingly, such extended surface members are not in widespread use for such applications.
SUMMARY OF THE INVENTION' The present invention seeks to reduce or avoid the disadvantages of the prior art devices described above. In particular, the invention seeks to provide a heat exchanger tube having an internal extended surface member which benefits from the heat exchange characteristics of the "compressed tube"designs, and yet is more readily
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repairable and replaceable since it does not require deformation of the tube.
According to the invention, there is provided a method of assembling a heat exchanger tube having an internal extended surface member, the method comprising the steps of: {i} selecting a heat exchanger tube, (ii) manufacturing an extended surface member, the extended surface member having a central bore, the bore having a predetermined crosssectional dimension, {iii} locating a resilient member within the bore, the resilient member having a crosssectional dimension greater than the predetermined crosssectional dimension when in its relaxed state, fiv) inserting the extended surface member into the tube with the resilient member stretched in the longitudinal direction, and {v} allowing the resilient member to relax.
Preferably, the extended surface member in its free state is a sliding fit within the tube.
It will be understood that stretching the resilient member in its longitudinal direction reduces its lateral dimension, and specifically reduces its lateral dimension to no greater than the lateral dimension of the bore. In this condition, the resilient member imparts little or no lateral (expanding) force upon the extended surface member. When the longitudinal stretching force is removed, however, and the resilient member is allowed to relax, it seeks to expand radially, and in turn expands the extended surface member into thermal engagement with the tube.
Desirably, the bore is of substantially circular crosssection. Desirably also, the resilient member is of substantially circular cross-section in its relaxed state. Preferably, the resilient member is of nitrile, or other suitable forms of synthetic rubber such as Viton (TM) or silicon rubber.
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The extended surface member can be made in two parts having engageable longitudinal surfaces. Preferably, each of the two parts defines a part of (ideally substantially half of) the bore. Alternatively, the extended surface member can be made in one part having a longitudinal split, and the wall surrounding the bore can be sufficiently flexible to permit the extended surface member to be expanded into thermal engagement with the tube.
Preferably, the extended surface member is of metal, usefully aluminium, and is preferably formed as an extrusion (or as two extrusions, as the case may be). Preferably, the extended surface member when viewed in cross section has a number of radial fins, each fin having a peripheral end which is adapted to engage the tube. The end of each fin opposed to its peripheral end is preferably connected to a wall surrounding the bore (or part-bore, as the case may be).
Desirably, the tube is a standard heat exchanger tube, e. g. a copper tube having an outside diameter of 19.05 mm (3/4 inch) and a wall thickness of 20 gauge ("standard wire gauge"). Since the tube is not compressed or otherwise deformed during the assembly process of the present invention, if a replacement is required a standard tube can be obtained. Standard tubes for use in heat exchangers (such as the tube described above) are readily available in many countries of the World. In addition, the extended surface members can be manufactured to fit within the standard tubes, and so are also of"standard"dimensions.
It is therefore foreseen that a replacement heat exchanger tube could be assembled and fitted in a matter of days, so reducing the duration for which a container ship for example might need to be taken out of service.
According to another feature of the invention, there is provided a heat exchanger tube assembled by the method as defined herein. The heat exchanger tube comprises a tube
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containing an extended surface member, the extended surface member having a bore containing a resilient member, the resilient member urging a part or parts of the extended surface member against the inside surface of the tube wall.
Desirably, the resilient member lies within the bore for substantially the full length of the bore.
BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described, by way of example, with reference to the accompanying schematic drawings, in which: Fig. l shows a step in the assembly process of the heat exchanger tube according to the invention, as the extended surface member is being introduced into the tube; Fig. 2 shows a later step in the assembly process, following the complete introduction of the extended surface member into the tube; Fig. 3 shows a cross-sectional view of a first embodiment of extended surface member; and Fig. 4 shows a cross-sectional view of a second embodiment of extended surface member.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Fig. l shows an extended surface member 10 during its introduction into a tube 12 during the performance of the method according to the invention.
In the embodiments of Figs. 1 and 2, the extended surface member 10 is made of two separate extruded components of
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aluminium, the cross-section of which is shown in Fig. 3. Thus, the components lOa and lOb are identically formed (perhaps initially being part of the same extrusion which is subsequently cut into separate lengths), and include five radial fins 14 supported upon a wall 16.
In other embodiments, more or fewer than five fins can be provided as desired, and it will be understood that the number and thickness of the fins, and the material from which the extended surface member is made, can be varied to suit the heat exchange characteristics required.
A recess 20 is formed into the wall 16, which recess defines a part of (in this embodiment substantially half of) a central bore 22 of the extended surface member 10.
The peripheral end 24 of each fin 14 is curved slightly to match the curvature of the inside surface 26 of the tube 12, and the length of each fin is suited so that the ends 24 can all lie on a circle of a diameter corresponding to the diameter of the inside surface 26.
Located within the central bore 22 is a resilient member 30, which in this embodiment is a length of nitrile. In this embodiment, the resilient member and the bore 22 are of substantally circular cross-section, though it will be understood that other cross-sectional forms, such as rectangular and in particular square, could alternatively (though less preferably) be used if desired.
The components 10a, 10b each have surfaces 32 which can engage each other (these surfaces are engaging in Fig. 1, but are shown separated in Fig. 3, for clarity; Fig. 3 represents the extended surface member 10 in its"fitted"condition in which the ends 24 of the components lOa and lOb all lie on the same circle corresponding to the inside surface 26 of the tube 10).
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When the surfaces 32 engage as in Fig. 1, the extended surface member 10 is a sliding fit within the tube 12 (the gap between the extended surface member and the tube being exaggerated in Fig. l, for clarity).
The resilient member 30 has a diameter D when it is in its relaxed state, and it is arranged that the diameter D slightly exceeds, or is at least as great, as the diameter d of the bore 22 when in its fitted condition (see Figs. 2 and 3). However, the resilient member 30 can be stretched longitudinally as shown in Fig. l, which reduces its diameter to less than or equal to the size of the bore 22 when the surfaces 32 are in engagement.
Accordingly, when the resilient member 30 is stretched longitudinally as shown in Fig. l, its diameter reduces and permits the surfaces 32 to engage (or at least move close together), whereupon the extended surface member 10 can be slid into the tube 12. When the extended surface member 10 has been inserted into position within the tube (Fig. 2) the resilient member 30 can be released allowing it to relax.
Relaxation of the resilient member causes its length to decrease and its diameter to increase, the increase in its diameter separating the surfaces 32 and pressing the ends 24 of the fins 14 towards and into engagement with the inside surface 26 of the tube 12.
Whilst it can be arranged that the diameter D of the resilient member 30 in its relaxed state exactly matches the diameter d of the bore 22 in the fitted condition, it is clearly desirable that the diameter D exceed the diameter d, so that even when the resilient member 30 has relaxed to the fullest extent possible its diameter is maintained less than D, so that it continues to provide an outwards force upon the bore 22. Also, if the diameters D. and d were chosen to match, manufacturing tolerances might result in the inside diameter of the tube being greater than expected for part of the length of the tube, which would result in poor contact
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between the extended surface member and the tube. In one embodiment, therefore, the diameter d could be 3 mm and the diameter D could be 3.5 or 4mm, for example.
One end of the resilient member 30 has a lug 34 permanently secured thereto, the size of the lug preventing its passage through the bore 22 whilst the components 10a, b are located within the tube 12. The other end of the resilient member 30 is fitted with a cross-bar 36 which can be used to apply the tension necessary to stretch the resilient member 30.
The cross-bar 36 may be gripped by the hand of an assembler, or else a suitable tool or machine may be used to apply a force between the cross-bar 36 and the end 38 of the extended surface member 10.
As above indicated, and as shown in Fig. 2, when the resilient member 30 is allowed to relax, i. e. the cross-bar 36 is released, the length of the resilient member 30 reduces, and its diameter increases. As the diameter of the resilient member increases (towards its relaxed diameter D), the components lOa and lOb are forced apart (i. e. the surfaces 32 become separated), until the ends 24 of each of the fins 14 engage the inside surface 26 of the tube 12. It will be understood that the force generated by the relaxing and expanding resilient member 30 can be arranged to be sufficient to force the ends 24 against the inside surface to provide good thermal transfer between the extended surface member 10 and the tube 12.
In this embodiment, the tube 12 is of copper, having an external diameter of 19.05 mm (3/4 inch), and having a wall thickness of 20 gauge. It is therefore a standard heat exchanger tube which is widely available in many countries of the World. The components 10a, lOb are manufactured for such a tube, and can if desired be made in advance and held in stock for use when required. It will be understood that a number of differently-sized components will be required for the different sizes and wall-thicknesses of tubes.
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However, since the wall-thickness of tubes is in some cases known to vary along the length of the tube (due to manufacturing tolerances), it may be that there is sufficient tolerance within the resilient member and extended surface member to permit one size of component to fit within tubes having slightly different wall thicknesses, e. g. the same component might be used with a tube having a 19.05 mm outside diamter and a wall thickness of 19 or 20 gauge.
In the embodiment of Figs. 1 and 2, the length L of the tube is 2 metres; such a length is not unusual for the heat exchanger of the refrigeration unit of a container ship, for example, and heat exchanger tubes of greater length are known. In this embodiment the extended surface member is also substantially of the length L, though it will be understood that in other (though less desirable) embodiments the length of the extended surface member could be less than L, if an extended surface member was not required for the full length of the tube in a particular application.
Both the tube 12 and the components 10a, lOb may be made in longer lengths than L, and only cut to the desired length L when required.
It will be understood that the resilient member 30 must be allowed to relax so that it can expand the extended surface member into heat-transfer engagement with the tube; this relaxation might take several hours to complete. Vibrating the tube might reduce the time taken for the resilient member to relax to the fullest extent possible within the bore (i. e. when the ends 24 of all of the fins 14 have been forced against the inside surface 26). It is recognised by heat exchanger engineers that the tube may be impacted, the sound of the impact being indicative of whether or not there is adequate engagement between the extended surface member and the tube (good engagement will be indicated by a solid impact noise, whereas poor engagement will be indicated by a
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rattling noise which will be readily identifiable by a skilled engineer).
When the resilient member has relaxed to the fullest extent possible, the exposed end (and the cross bar 36) may be cut off. Clearly, it is desired that the relaxed length of the resilient member 30 be slightly greater than L, to ensure that the resilient member 30 will always extend beyond the end of the bore 22, and can be cut to length as a final assembly step. The distance by which the resilient member 30 projects from the end of the bore 22 can be used as an indication of the state of relaxation of the resilient member, and in particular whether it is has become fully or only partially relaxed.
Fig. 4 shows an alternative embodiment of extended surface member 40. The extended surface member 40 is made as a single component, and in this embodiment also is of extruded aluminium. The extended surface member 40 is in most respects very similar to the extended surface member 10, and has ten radial fins 42 with ends 44 which are curved to match the inside surface of the tube to which it is intended to fit. In its rest state as shown in Fig. 4, the ends 44 of the fins 42 lie substantially on a circle corresponding to the inside surface of the tube.
It is arranged that the extended surface member 40 is sufficiently flexible to allow the longitudinal split 46 to open and close slightly. This flexibility arises from the material from which the extended surface member 40 is made, and from the thickness of the wall 50. In particular, the extended surface member 40 should be sufficiently flexible to permit it to be slid inside a tube (such as the tube 12 of Figs. 1 and 2), with the split 46 closing up as necessary to provide the sliding clearance required. In addition, when a resilient member (such as the resilient member 30 of Figs. 1 and 2) is allowed to relax within the bore 52 of the extended surface member 40, the split can be opened
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sufficiently to press the ends 44 of the fins 42 against the inside surface of the tube so as to provide effective thermal transfer between the extended surface member and the tube.
In the embodiment shown the split 46 is left open, but if it is desired to close this split it can be filled with a flexible material such as mastic or silicone.
The material from which the resilient member is made should be suited to the temperature environment to which it will be subjected. As above indicated, the material may be nitrile, Viton (TM) or silicon rubber, for example, which are suited to particular temperature ranges and have the desired resilience needed of the resilient member. Clearly, other synthetic or natural materials could be utilised if desired and suited to a particular application.
It may be that for particularly long heat exchanger tubes, a single resilient member would not be able to relax throughout its complete length, i. e. when the resilient member becomes very long the friction created between a relaxed portion adjacent the"cross bar end"of the tube could prevent the resilient member moving along the bore so that a more distant section of the resilient member can relax. For particularly long heat exchanger tubes, therefore, it would be possible to fit an extended surface member into each end of the tube, each extended surface member (and therefore each resilient member) being slightly less than half of the length of the tube, one of the resilient members being stretched from one of the ends of the tube, the other resilient member being stretched from the other end of the tube. The extended surface members could abut at the centre of the tube, but in practice a slight gap would likely be present, within which the respective lugs 34 would lie.
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In the following claims reference is made to a"crosssectional dimension"of the bore and of the resilient member, it being recognised that the invention could utilise a resilient member which engaged the periphery of the bore at as few as two radial points to provide a bi-directional outwards force. The embodiments described, however, show the preferred arrangement in which the resilient member fills the bore (and engages the complete periphery of the bore) and provides an onmi-directional outwards force; in these embodiments in addition to the cross-sectional dimension (s) of the relaxed resilient member exceeding the cross-sectional dimension (s) of the bore, the crosssectional area of the relaxed resilient member also exceeds the cross-sectional area of the bore.

Claims (16)

  1. CLAIMS 1. A method of making a heat exchanger tube having an internal extended surface member, the method comprising the steps of: {i} selecting a heat exchanger tube, (ii) manufacturing an extended surface member, the extended surface member having a bore with a predetermined cross-sectional dimension, {iii} locating a resilient member within the bore, the resilient member when in its fully relaxed state having a cross-sectional dimension greater than the predetermined cross- sectional dimension, fiv) stretching the resilient member in the longitudinal direction, fvj inserting the extended surface member into the tube, and {v} allowing the resilient member to relax.
  2. 2. A method according to claim 1 in which the extended surface member without the resilient member is a sliding fit within the tube.
  3. 3. A method according to claim 1 or claim 2 in which the extended surface member is manufactured in two parts having engageable longitudinal surfaces.
  4. 4. A method according to claim 3 in which each of the two parts defines a part of the bore.
  5. 5. A method according to claim 1 or claim 2 in which the extended surface member is manufactured in one part having a longitudinal split, and with a wall surrounding the bore which is sufficiently flexible to permit the extended surface member to be expanded into thermal engagement with the tube.
  6. 6. A heat exchanger tube assembled by the method according to any one of claims 1-5, the heat exchanger tube comprising a tube containing an extended surface member, the extended surface member having a bore
    <Desc/Clms Page number 16>
    containing a resilient member, the resilient member urging a part or parts of the extended surface member against the inside surface of the tube.
  7. 7. A heat exchanger tube according to claim 6 in which the bore is of substantially circular cross-section.
  8. 8. A heat exchanger tube according to claim 6 or claim 7 in which the resilient member is of substantially circular cross-section in its relaxed state.
  9. 9. A heat exchanger tube according to any one of claims 6- 8 in which the resilient member is of nitrile, Viton (TM) or silicon rubber.
  10. 10. A heat exchanger tube according to any one of claims 6- 9 in which the extended surface member is of metal.
  11. 11. A heat exchanger tube according to claim 10 in which the extended surface member is of aluminium.
  12. 12. A heat exchanger tube according to claim 111 in which the extended surface member is formed as an extrusion.
  13. 13. A heat exchanger tube according to any one of claims 6- 12 in which the extended surface member when viewed in cross section has a number of radial fins, each fin having a peripheral end which is adapted to engage the tube.
  14. 14. A heat exchanger tube according to any one of claims 6- 13 in which the resilient member lies within the bore for substantially the full length of the bore.
  15. 15. A heat exchanger tube constructed and arranged substantially as described with reference to Figs. 1-3 or Fig. 4 of the accomanying drawings.
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  16. 16. A method of assembling a heat exchanger tube substantially as described in relation to Figs. 1-3 or Fig. 4 of the accompanying drawings.
GB0125828A 2000-10-27 2001-10-29 Method of making a heat exchanger tube, and heat exchanger tube made thereby Withdrawn GB2376432A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB0026411A GB0026411D0 (en) 2000-10-27 2000-10-27 Method of making a heat exchanger tube and heat exchanger tube made thereby

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GB0125828D0 GB0125828D0 (en) 2001-12-19
GB2376432A true GB2376432A (en) 2002-12-18

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GB0026411A Ceased GB0026411D0 (en) 2000-10-27 2000-10-27 Method of making a heat exchanger tube and heat exchanger tube made thereby
GB0125828A Withdrawn GB2376432A (en) 2000-10-27 2001-10-29 Method of making a heat exchanger tube, and heat exchanger tube made thereby

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GB0026411A Ceased GB0026411D0 (en) 2000-10-27 2000-10-27 Method of making a heat exchanger tube and heat exchanger tube made thereby

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2944910A1 (en) * 2014-05-13 2015-11-18 Grand Hall Enterprise Co., Ltd. Heat exchanger tube

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Publication number Priority date Publication date Assignee Title
US4418457A (en) * 1982-01-21 1983-12-06 Cities Service Company Apparatus and process for expanding to join a tube into a tube sheet opening
US4419802A (en) * 1980-09-11 1983-12-13 Riese W A Method of forming a heat exchanger tube
US4420866A (en) * 1982-01-25 1983-12-20 Cities Service Company Apparatus and process for selectively expanding to join one tube into another tube
US5207247A (en) * 1989-09-22 1993-05-04 Hood Joy S Method of tube plugging

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Publication number Priority date Publication date Assignee Title
US4419802A (en) * 1980-09-11 1983-12-13 Riese W A Method of forming a heat exchanger tube
US4418457A (en) * 1982-01-21 1983-12-06 Cities Service Company Apparatus and process for expanding to join a tube into a tube sheet opening
US4420866A (en) * 1982-01-25 1983-12-20 Cities Service Company Apparatus and process for selectively expanding to join one tube into another tube
US5207247A (en) * 1989-09-22 1993-05-04 Hood Joy S Method of tube plugging

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2944910A1 (en) * 2014-05-13 2015-11-18 Grand Hall Enterprise Co., Ltd. Heat exchanger tube

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GB0125828D0 (en) 2001-12-19

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