Title:
Heat exchanger with passive in-line temperature control
Kind Code:
A1


Abstract:
The invention describes a heat exchanger that continuously and passively regulates the transfer of heat across each part of the heat exchanger's partitions. Such partitions composed of typically two tubes, one inside the other's bore, that at various points, contact each other or separate from each other, thereby increasing or decreasing heat transfer across their walls at those points. Such separations and contacts being spontaneously effected by changes in the shape of at least one of the tubes which is driven by elements connected to that tube and which change their shape in response to temperature changes, such as shape memory alloys (SMA's) or bi-metal strips.



Inventors:
Unsworth, John Duncan (Hamilton, CA)
Application Number:
09/811832
Publication Date:
09/26/2002
Filing Date:
03/20/2001
Assignee:
UNSWORTH JOHN DUNCAN
Primary Class:
Other Classes:
165/96
International Classes:
A47J27/00; F28F1/00; F28F13/00; F28F27/00; A47J27/56; A47J37/12; (IPC1-7): F28F27/00
View Patent Images:
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Primary Examiner:
DUONG, THO V
Attorney, Agent or Firm:
John D. Unsworth (c/o Vasotech Corp. 7 Innovation Drive, Suite 107, Flamborough, ON, L9+1 7+19, CA)
Claims:

What is claimed is:



1. A system that controls thermal energy from passing from one medium to another medium, comprising: two or more partitions that are thermally conductive and at least one of the said partitions is connected to a container or to the end of another partition, in such a way that they in cooperation physically segregate the said media preventing them from substantially commingling with one another; and said partitions where they are separated from each other act to significantly reduce thermal transmission between them, across the points of separation, and consequently, between said media, across those same points of separation, and said partitions where they are contacting each other act to significantly increase thermal transmission between them across the points of contact and consequently, between the said media, across those same points of contact, and at least one of the said partitions is flexible which simultaneously allows all or parts of its surface to contact or separate from, a corresponding part of the surface of another of the said partitions, and at least one motive element that changes shape in response to changes in temperature, and the said motive element is in contact with or in transmission with, and has its temperature changed by, and in relation to, the changes of temperature of the medium to which it is most proximate and does not change its shape or does less so in relation to another medium to which it is not as proximate, and the said motive element, as its parts change shape in response to the temperature of the most proximate medium, in turn changes the shape of a flexible partition to which it is connected or a part and the change of shape can cause all or corresponding parts of the surface of the said flexible partition to contact or separate from all or corresponding parts of the surface of another of the said partitions and thereby alter the thermal transmission from one media through to the other across the parts of the partitions that are separated or in contact.

2. A system that controls thermal energy from passing from one medium to another medium, comprising: two or more partition tubes that line or are lined or both by at least one other partition tube, and said partition tubes are thermally conductive and at least one of the said partition tubes is connected to a container, or to the end of another partition tube, in such a way that they in cooperation physically segregate the said media preventing them from substantially commingling with one another; and said partition tubes where they are separated from each other act to significantly reduce thermal transmission between the said partition tubes, across the points of separation, and consequently, between said media, across those same points of separation, and said partition tubes where they contact each other act to significantly increase thermal transmission between them, across the points of contact, and consequently, between the said media, across those same points of contact, and at least one of the said partition tubes is flexible which allows all or a part of its surface to alternatively contact and separate from, a corresponding part of the surface of another of the said partition tubes, and at least one motive element that changes shape in response to changes in temperature, and the said motive element is in contact with or in transmission with, and has its temperature changed by, and in relation to, the changes of temperature of the medium that it is most proximate to and does not change its shape or does less so in relation to another medium to which it is not as proximate, and the said motive element, as it changes shape in response to the temperature of the most proximate medium, in turn changes the shape of those parts of the flexible partition tube to which it is connected or of which it is part, and those parts of the said flexible partition tube which have their shape changed, depending upon the preferred embodiment, may contact or separate from corresponding parts of the surface of another partition tube and thereby alter the heat transmission from one media through to the other across the parts of the partition tubes that are separated or in contact.

3. A system of claim 2, wherein a flexible partition tube 5 includes at least one bellow that allows the said flexible partition tube 5 to expand and; and in cooperation with the cross-sectional shape of any partitions it lines or is lined by, facilitates contacting and separating from any of those other partitions.

4. A system of claim 2, wherein a flexible partition tube 5 contains features that assist in aligning the said flexible partition tube 5 with another partition tube that it immediately lines or is immediately lined by, perhaps in cooperation with some aligning features contained in the said partition tubes it immediately lines or is lined by, that facilitates the intended and substantial separation or the substantial contacting of the said flexible partition tube 5 with the said partition tubes it immediately lines or is lined by.

5. A system of claim 2, wherein a flexible partition tube 5 contains one or more bellows 7 that assist in aligning the said flexible partition tube 5 with another partition tube that it immediately lines or is immediately lined by, perhaps in cooperation with some aligning features contained in the said partition tubes it immediately lines or is lined by, that facilitates the intended and substantial separation or the substantial contacting of the said flexible partition tube 5 with the said partition tubes it immediately lines or is lined by.

6. A system of claim 2, wherein a flexible partition tube 5 has one or more motive elements connected to it or that are incorporated into it, that change shape in response to the temperature of the medium that is most proximate to it, and that in turn change the cross-sectional shape of the flexible partition tube, and thereby cause the said flexible partition tube 5 to expand and contract in a direction that causes the said flexible partition tube 5 to either contact or separate from any partition tubes it lines or is lined by.

7. A system of claim 2, wherein the motive elements are made of shape memory alloy (SMA), or other shape memory material and has a memorized shape which is relaxed by the extraction of thermal energy, and is at least partly recovered with the application of thermal energy thereby causing the motive element to change shape upon the said extraction of thermal energy or by the application of thermal energy, such energy being applied or extracted by the temperature of the medium that is most proximate to it, and that in turn change the shape of the flexible partition, and thereby cause the said flexible partition tube 5 to expand and contract, in cooperation with any other spring in the said flexible partition tube, and thereby cause the expanding or contracting flexible partition tube 5 to either contact or separate from any partition tubes it lines or is lined by.

8. A system of claim 2, wherein the motive element is made of shape memory alloy (SMA), wherein the said motive element 9 is deformed by the spring of the flexible partition tube, normal to its longitudinal axis, from a previously memorized shape in a deformation state selected from one or more of bending, tension and torsion, and at a temperature at or above an austenite finish temperature of the SMA material such that the SMA material exhibits superelastic behavior by forming stress-induced martensite or exhibits pure elastic behavior, or some combination of both superelastic and elastic behavior in different areas or layers of the said motive element, and wherein the application of thermal energy, by the temperature of the medium that is most proximate to it, causes the SMA material to increase in temperature, which causes the stiffness of the said motive element to increase and thereby attempt to resume its memorized shape either by a concomitant increase in elastic modulus of the SMA material or by an increase in a value of a superelastic stress plateau, which is a stress at which the stressinduced martensite is first formed, or by a combination thereof, or other more complex deformation and recovery paths occurring as a function of stress, strain and temperature, including complex sub-loops at temperatures at or above the austenite finish temperature of the SMA material, and in attempting to resume its memorized shape overcomes or partly overcomes the said deformation by the spring of the flexible partition tube; and when energy is extracted from it by the temperature of the medium that is most proximate to it, causes the said motive element to relax and be partly or completely overcome by the spring of the flexible partition tube, and that the said stiffness and relaxation of the said motive element acting in cooperation with the said spring of the flexible partition tube changes the cross-sectional shape of the said flexible partition tube, and thereby cause the said flexible partition tube 5 to expand or contract, and cause the expanding or contracting flexible partition tube 5 to either contact or separate from any partitions it lines or is lined by.

9. The system of claim 2, wherein the motive element is made of bi-metal strips of metal, or other materials, that change their shape upon the said extraction of thermal energy or by the application of thermal energy, such energy being applied or extracted by the temperature of the medium that is most proximate to it, and that in turn change the shape of flexible partition tube's 5, and thereby cause the said flexible partition tube 5 to expand or contract, in cooperation with any other spring in the flexible tube, and thereby cause the expanding or contracting flexible partition tube 5 to either contact or separate from any partition tubes it lines or is lined by.

10. The system of claim 2, wherein flexible partition tube 5, can simultaneously and along different parts of its wall surface, in response to the varying temperatures of media acting on motive elements 9 and said flexible partition tube 5 adjacent to those parts, contact and separate from the immediately adjacent parts of partition tubes that the said flexible partition tube 5 lines or is lined by.

11. The system of claim 2, wherein the flexible partition tube 5 includes means for imparting or adding flexibility to the said tube, and such flexibility allows the said flexible partition tube 5 to expand and contract in directions that facilitate contacting and separating the said flexible partition tube 5 from another partition tube that it immediately lines or is immediately lined by.

12. The system of claim 2, wherein the flexible partition tube 5 includes means for imparting or adding flexibility to the said tube, and such flexibility allows the said flexible partition tube 5 to expand and contract in directions that facilitate contacting and separating the said flexible partition tube 5 from another partition tube that it immediately lines or is immediately lined by, and those means include any number of bellows 7 that form a part of the wall of the said flexible partition tube, and run along the walls of the flexible partition tube continuously or discontinuously, straight, annularly, longitudinally, helically or along any required path.

13. The system of claim 2, wherein the flexible partition tube 5 includes means for maintaining alignment with the partition tube that it immediately lines or is immediately lined by, and such means includes any number of bellows 7 that form a part of the wall of the said flexible partition tube, and run along the walls of the flexible partition tube continuously or discontinuously, straight, annularly, longitudinally, helically or along any required path, and such bellows 7 are shaped such that they allow the said flexible partition tube to expand and contract, and such bellows 7 are shaped such that they cooperate with a T-rail 8 that is connected to or a part of the facing wall of a partition tube that the said flexible partition tube immediately lines or is immediately lined by, and and said T-rails run along the walls of the flexible partition tube in a complementary manner to the said bellows 7 with which they cooperate, and when the said flexible partition tube 5 lines another partition tube, to which the T-rail is connected or is a part and when the said flexible partition tube 5 contracts, the bellows 7 grasps the said T-rail 8; and the skirt 8b, waste 8c and the bulb 8d of the T-rail act in concert to hold the said flexible partition tube at a proper distance from the inside walls of the partition wall to which the T-rail is connected, perhaps in concert with other bellow and T-rail combinations located around the radius of the flexible partition tube 5 and the other partition tube it lines. and when the said flexible partition tube 5 lines another partition tube, to which the T-rail is connected or a part of and when the said flexible partition tube expands, the bellows 7 release the said skirt and said waste of the said T-rail 8, but the bellows maintain contact with the head of the bulb 8d of the T-rail 8, which in cooperation with perhaps one or more other sets of bellows 7 and T-rail 8 combinations, act to hold the said flexible partition tube at a proper distance from the inside of the walls of the partition wall it lines, until the said flexible partition tube is fully expanded and in some preferred embodiments fully contacts the inside of the walls of the partition tube it lines, and when the said flexible partition tube 5 is lined by another partition tube, to which the T-rail is connected and when the said flexible partition tube expands, the bellows 7 release the skirt and waste of the said T-rail 8, but still maintain contact with the head of the bulb 8d, which in cooperation with perhaps another set of bellows 7 and T-rail 8, but preferably two additional sets, evenly spaced around the perimeter of the said flexible partition tube, acts to hold the said flexible partition tube at a proper distance from the outside walls of the partition wall to which the T-rail is connected, and when the said flexible partition tube 5 is lined by another partition tube, to which the T-rail is connected and when the said flexible partition tube 5 contracts, the bellows 7 grasp the skirt 8b, waste 8c and bulb 8d of T-rail 8, and act to hold the said flexible partition tube at the proper distance from the outside of the walls of the partition wall to which the T-rail is connected, until the said flexible partition tube is fully contracted and in some preferred embodiments fully contacts the outside walls of the partition wall to which the T-rail is connected.

14. The system of claim 2, wherein there are pressure relief means that relieve the pressure difference hat may develop between the flexible partition tube and another partition tube that the said flexible partition tube lines or is lined by, when the said partition tube expands away from or approaches that other partition tube.

15. The system of claim 2, wherein the space between the flexible partition tube 5 and another partition tube that the said flexible partition tube lines or is lined by, forms a vacuum when the said partition tube expands away from that other partition tube, thereby further interrupting the conduction of heat across the said space 6.

16. The system of claim 2, wherein pressure equalization means are included to neutralize the effect of the pressure of the medium contained in a flexible partition tube, or surrounding a flexible partition tube, on the shape of the flexible partition tube.

17. The system of claim 2, wherein pressure equalization means are included to neutralize the effect of the pressure of the medium contained in a flexible partition tube 5, or surrounding a flexible partition tube 5, on the shape of the flexible partition tube, and these means include a means for keeping separate the two streams of media that are separated by the partition tubes.

18. The system of claim 2, wherein the motive element or elements are connected to various parts of the flexible partition tube to control the expansion and contraction of each part of the said flexible partition tube in response to the temperature and temperature changes in the medium most proximate to the said motive element, and said motive element or elements can be continuous or discontinuous, and the said motive element or elements can form part of the flexible partition tube 5, be connected or attached to either side of the bellows 7 or be connected at both ends to the inside walls of the said flexible partition tube or be located at other places within or outside the said flexible partition tube 5 that change the shape of the said flexible partition tube in response to changes in temperature of the medium most proximate to it.

16. The system of claim 2, wherein the motive element is further isolated from the thermal effects of the medium on the other side of the other thermal partition by the interposition of insulation and insulation means including flexible insulation.

17. The system of claim 2, wherein the motive element is made more responsive to the medium in which it is most proximate, by the addition of fins and other means of increasing the surface area of the said motive element.

18. The system of claim 2, wherein the means of aligning the flexible partition tube from other partition tubes is the inclusion of spurs on the folds in the flexible partition tube 5 proximal to the bellows, that act to align and control the separation and contacting of the flexible partition tube and the other partition tube that it immediately lines or is immediately lined by.

19. The system of claim 2, wherein the motive element and its complementary bellows to which it is attached includes means for increasing the force and distance over which the force is applied to cause the connected bellows and groove to change shape, in response to temperature changes in the medium most proximal to the said motive element.

20. The system of claim 2, wherein the system may include a T-rail 8, referred to as the “dog bone” T-rail that controls the motion of two flexible partition tubes 5, 5a that have facing bellows, and how the geometry of the said dog bone T-rail can be varied to effect the functions of the partition tubes and the consequent conductivity between the media separated by the said partition tubes.

21. The system of claim 2, wherein the relative shape of the flexible partition tube and the other partition tube that it lines or is lined by, permits the gradual contacting and separation of the partition tubes, and thereby the gradual application or extraction of heat across the partition tubes.

22. The system of claim 2, wherein partition tubes are sectioned longitudinally to facilitate the assembly of said partition tubes around each other.

23. The system of claim 2, wherein motive elements are snapped over partition tubes that are sectioned, longitudinally along the bellows, to hold the said sectioned tubes together, to facilitate easier assembly.

24. The system of claim 2, wherein methods to further thermally isolate the partition tubes and the motive element by treating the facing surfaces of the partition tubes to reduce radiant and convective heat transmission.

25. The system of claim 2, wherein the system is used to regulate the temperature of working medium or product medium and both for various purposes.

26. The system of claim 2, wherein the system is used to regulate the temperature of working medium or product medium and both for regulating the temperature of fuel for efficient combustion, including engines and heating devices, by using waste heat from the engine or the exhaust stream or the exhaust flue.

27. The system of claim 2, wherein the system is used to regulate the temperature of working medium or product medium and both for controlling the temperature of the cooling medium used in an engine.

28. The system of claim 2, wherein the system is used to regulate the temperature of working medium or product medium and both for controlling the temperature of medium in a container, to prevent over-heating or under-heating of the said medium.

29. The system of claim 2, wherein the system is used to regulate the temperature of working medium or product medium and both for heat storage, including storing heat recovered from the exhaust stream of an engine or from the engine itself during operation for later recovery, usually at cold-start up, for heating the vehicle, the engine, a catalytic converter, battery or any other device that requires heating.

30. The system of claim 2, wherein the flexible partition tube is given a cross-sectional shape normal to its longitudinal axis that is complementary to the cross-sectional shape normal to its longitudinal axis that of another partition tube that it lines or is lined by such that when the flexible partition tube is contracted or expanded toward the said other partition tube that the two tubes have a greater surface in contact than when the said flexible partition tube is contracted or expanded away from the other partition tube, by in both cases the motive element responding to the temperature of the medium in which it is most proximate and it in turn expanding or contracting the said flexible partition tube, and including the preferred embodiment where the flexible tube is approximately elliptical and the other partition tube it lines or is lined by is approximately round, or the other way around.

31. The system of claim 2, wherein the vacuum that may develop between the flexible partition tube and another partition tube that the said flexible partition tube lines or is lined by, when the said partition tube expands away from that other partition tube is relieved by the introduction of ambient air or some other gas having a higher insulative value such as argon or carbon dioxide.

32. The system of claim 2, wherein carbon dioxide or other gas that is a good absorber of radiant energy is circulated through the space between partition tubes, and perhaps cooled outside the system illustrated herein, to enhance the thermal isolation of the media that are separated by the thermal partitions.

33. The system of claim 2, wherein various materials and interposed between the partition tubes that act as thermal insulators, when the said partition tubes are separated, but are relatively good thermal transmitters when the said partition tubes are in contact.

34. The system of claim 2, wherein various surface treatments, including reflective surfaces, are applied to the facing surfaces of the said partition tubes to reduce thermal transmission by radiation between the said partition tubes and between the media they separate.

35. The system of claim 2, wherein one or more of the said partition tubes can have closed ends.

36. The system of claim 2, wherein means are described for making the flexible tube flexible in a direction normal as well as parallel to the said tube's axis, including bellows, that form part of the wall of the said flexible tube and that run continuously or discontinuously along the wall of the said tube in any direction including, annularly, or straight or helically along or around the longitudinal axis of the tube.

37. The system of claim 2, that includes means to create and maintain a vacuum between the partition tubes to reduce thermal energy transfer across the said tubes.

38. The system of claim 2, wherein the said partition tubes do either not contact or separate from each other, but rather approach or recede from each other and in so doing vary the thermal transmission between and through them and consequently between the media they separate.

40. The system of claim 1, wherein the said partition tubes do either not contact or separate from each other, but rather approach or recede from each other and in so doing vary the thermal transmission between and through them and consequently between the media they separate.

Description:

FIELD OF THE INVENTION

[0001] The field of invention is heat exchangers and thermostats or temperature controllers.

BACKGROUND OF THE INVENTION

[0002] Heat exchangers add or remove heat from one medium to another across a thermally conductive partition. One medium, hereinafter called the “product” or the “product medium” is heated or cooled by the working medium giving up heat or absorbing heat, respectively, across the said conductive partition. Controlling the temperature of the product usually involves detecting the temperature of the product and then varying the temperature of the working medium to bring the temperature of the product within the desired temperature range. This usually involves electronic means for detection and reporting and mechanical means, including valves, to vary the temperature of working medium acting on first the said conductive partition and then on the product.

[0003] There may be circumstances where the control means fail or are turned off, and the product remaining in the heat exchanger overheats.

[0004] There may also be circumstances where the product overheats at certain points during its passage through the heat exchanger due to fluctuations in the temperature of the working medium.

[0005] There may also be circumstances where it is desirable or convenient to maintain the working medium at a constant temperature, while at the same time maintaining the product at a specific temperature or within a range of temperatures.

[0006] What is needed therefore is a heat exchanger that controls the temperature of the product as it passes through the heat exchanger by controlling the transmission of heat across the said partition.

[0007] What is also needed is a heat exchanger that controls the temperature of the product medium passively, without resort to electronic or mechanical devices.

[0008] What is also needed is a heat exchanger that controls the temperature of the product medium without significantly varying the flow of the product through the heat exchanger.

[0009] What is needed is a heat exchanger that does not allow the product to come into contact with excessive temperature gradients, including those cases where the working medium is thermally heterogeneous.

SUMMARY OF THE INVENTION

[0010] The invention is a heat exchanger that acts as a heat valve and that passively controls the conduction of heat, at every point across thermally conductive partitions separating the working medium from the product medium. The invention includes two or more parallel thermally conducting partitions between the working medium and the product medium that either contact each other: enhancing thermal conduction; or separate: reducing thermal conduction. The void created by the separation being replaced with ambient air, a low conducting material, or a vacuum. The invention also includes means for maintaining the alignment of the said parallel partitions at each phase of separation and connection with each other.

[0011] Another important aspect of the invention is that the thermally conducting partitions are flexible in a direction that permits part or parts of the thermal conducting partitions to contact or separate at the same time in response to the temperature of the medium, whether working or product, that is most proximal to the said parts.

[0012] One preferred embodiment of the invention is a heat exchanger comprised to two or more thermally conductive tubes, one inside the other's bore, having parallel longitudinal axes. This arrangement is hereinafter referred to as a partition tube “lines” “lining or “being lined” by the other and includes the case where there is a space between them. These two tubes, each a partition, separate the first medium which is external to the sides of both tubes and the second medium which is inside the bore of the inside tube, one or both of the tubes being attached at both their ends to a container 1 or device that prevents the two media from contacting each other directly or substantially commingling. The said first medium and second medium can be either the working medium or the product medium depending upon the use to which the heat exchanger is put.

[0013] These partition tubes, together separate the working medium and the product. These thermally conductive partition tubes either contact each other: enhancing conduction, or separate: creating an annular space, a space containing a relatively low conducting medium or a vacuum, significantly controlling heat transfer.

[0014] The invention includes direct mechanical means, referred to herein as a “motive element” 9, that applies a force to effect the separation or the contacting of the said partitions at various points along the length of the partition tubes, in response to temperature changes of the medium, (working or product) in which the said motive elements are immersed or proximal to the said medium at those points. The temperature at which the motive elements change shape, their direction of shape change and the material chosen to make them, are all well known to the art and will be selected by the person designing the particular device. The force exerted by the motive elements works in cooperation with the flexible walls of a partition tube, to cause it to expand or contract along at least one axis normal to the longitudinal axis of the said flexible partition tube 5, and thereby cause the said flexible tube to either contact or separate from the other partition tube it is lining or which lines it. The expandability and contractility of the flexible partition tube is enhanced or effected by the inclusion of a bellow 7 that form part of the perimeter of the said flexible partition tube or by the inherent flexibility of the material from which the flexible partition tube is made or a combination of both. A preferred embodiment of the invention includes a flexible partition tube having a bellow 7 that also assists in aligning the flexible partition tube with respect to the other partition tube it lines or is lined by, so that the longitudinal axis of both partition tubes in approximately coincident at every stage of expansion and contraction of the flexible partition tube or tubes. This ensures that the flexible partition tube contacts and separates from the other partition tube, by expanding and contracting in a reproducible and predictable manner so that the heat transfer through the said two tubes is controllable.

[0015] In preferred embodiments of the invention, the flexible partition tube 5, in addition to being flexible in a direction normal to the flexible partition tube's 5 longitudinal direction, is also flexible in a direction parallel to the longitudinal direction of the said flexible partition tube 5. This longitudinal flexibility allows for the said flexible partition tube to expand and contract radially, normal to the longitudinal axis of the said flexible partition tube 5, in different parts along the length of the said flexible partition tube 5 at the same time, in cooperation with the motive element 9 responding to the varying temperatures of the medium 2 or 4 most proximate to it. This expansion and contraction, of parts of the flexible partition tube 5 can, depending upon the circumstances of the preferred embodiment, cause the flexible partition tube to contact or separate from another partition tube at those same parts, and again depending upon the circumstances of the preferred embodiment, thereby increase or decrease conduction across the partition tubes, at those same parts, and thereby the transport of energy between the two media 2 and 4, at those same parts. This aspect of the invention is its most important feature. This aspect of the invention allows for control of the flow of energy to and from the working media to and from the product media, and the control of the temperature of the product media, as the media is flowing through the heat exchanger.

[0016] In preferred embodiments of the invention the said direct mechanical means, the motive elements, that effect the separation or contacting are composed of thermally actuated bimetal materials or shape memory alloys (SMA), or other materials that change their shape in response to the changing temperature of the medium in which they are immersed or proximal to, and in turn change the shape of one or more of the flexible partition tubes, causing them to expand or contract, and by so doing contact or separate themselves from other partition tubes. The preferred embodiments of the invention also thermally isolate the motive elements from the other medium, the one in which they are not immersed or distant from, to ensure that their responses are solely to the medium in which they are immersed or most proximal to.

[0017] It is important to note that the tubes contact and separate in response to temperatures contained within the tube at each point along the length of the tubes. For example, as illustrated in FIGS. 2a, 2b, and 2c, the partition tubes 3 and 5 may contact along their entire lengths as illustrated in FIG. 2a with no space 6a between them, for example, when the product 4 first flows into the heat-exchanger and takes-up or gives-off heat from or to the working medium 2 through the relatively conductive contacted partitions 3 and 5. Later, as illustrated in FIG. 2b, and as perhaps, for example, the working fluid 4 heats up or cools down further, the product 4 in turn heats up or cools down before it completes its pass from left to right through the heat exchanger. At that point and at the other points along its passage through the heat exchanger, that the product reaches the desired temperature, the motive elements immersed in the product 4, in cooperation with the bellow in the flexible partition tube 5 that contains the product, cause the said flexible tube 5 to separate 6b from the fixed partition tube 3 and thereby reduce further conduction along those points of separation, as the product passes from left to right through the flexible partition tube 5. If for example the product's 4 flow is stopped, yet the working fluid 2 continues to provide heat or cooling, a dangerous condition might be created. FIG. 2c illustrates that in such circumstances all or virtually all of the flexible partition tube 5 can withdraw 6c from the fixed partition tube 3 to significantly reduce heat transfer to the working medium 2 and thereby avoid the dangerous condition.

[0018] A preferred embodiment of the invention is a tube lining a second tube, comprising the said two parallel partitions, in which both tubes have high thermal conductivity. In this example, the inner partition tube carries the product, the two partition tubes being immersed in the working medium save for their ends that are attached to the tank housing 1, although in some preferred embodiments only one of the partition tubes is actually attached to the a tank housing, with the other free floating and sealed to the other tube with a flexible or inflexible gusset; (in some other preferred embodiments of the invention a free floating partition tube need not be sealed and may even contain a slit running down the length of the flexible partition tube with the slit ends butting each other or overlapping and sliding one over the other to allow for expansion and contraction). The inner flexible partition tube contracts and expands, alternately causing the tubes to separate and to contact. When they contact, the heat transfer increases from the working medium through the two partition tubes to the product. When they separate, the said heat transfer from the working medium to the product decreases. In this preferred embodiment the inner partition tube contains means that allow the said tube to expand and contract. This expansion means can be a bellow that is an integral part of the flexible partition tube, alternatively the flexible partition tube can be off-round, for example elliptical, in which case the flexible partition tube would expand normal to its minor axis. The motive force for the expansion and contraction is provided by an element that in response to temperature changes of the product, in which it is bathed or most proximal, either directly or indirectly acts to expand or contract the bellow, or distort the elliptical flexible partition tube into a more round shape, and thereby presses parts of the flexible partition tube out against the walls of the outer tube, which it lines.

[0019] In this preferred embodiment, the motive element is a bi-metal strip of metal or shape memory alloy (SMA) or other shape memory material, that changes shape in response to temperature changes in the medium most proximate to it, and in the example to expand the bellows, or distorts the elliptical tube into a more round shape, thereby pushing the inner partition tube wall sections against the outside partition tube. For example the said motive means might be actuated when it cools in response to the falling temperature of the product, causing the motive element to expand, which in turn would cause most of the inner flexible partition tube, at that point, to contact the outer partition tube and thereby cause the two tube partition to become more conductive to the transfer of heat from the working medium to the product.

[0020] In some preferred embodiments of the invention the inner flexible partition tube can be made springy and the motive element can act against the spring. For example, the inner flexible partition tube can be sprung so that most of it is separated from the outer partition tube until the motive element acts to expand the flexible partition tube in response to a temperature demand of the product, causing it to contact the outer partition tube. Of course the spring and motive element could be set to act in the opposite way. This arrangement is particular useful where shaped memory alloy (SMA) is used for the motive element. For example, the memorized shape of the motive element would cause the walls of the inner flexible partition tube to contract from the inner wall of the outer partition tube, when the shaped memory alloy is heated above its austenitic start temperature (recovering its shape imparted at high temperature) overcoming the force of the spring. But the motive element allows the spring of the inner flexible partition tube to expand the said inner flexible partition tube and cause it to contact the inner walls of the outer partition tube when the said motive element cools below its martensitic start temperature; that is when the said motive becomes relatively compliant and yields to the force of the spring. This example lends itself to applications where it is sought to keep the temperature of the product within a certain range of temperatures. Shaped memory alloys have a hysteresis between the austenitic finish temperature and the martensitic start temperature as well as between the martensitic finish temperature and the austenitic start temperature. In the above example this allows the inner partition tube to remain in either its expanded mode, contacting the outer partition tube, or in its contracted mode, isolated from the temperature of the outer partition tube while the product's temperature varies within a temperature range approximately the same as the said hysteresis temperature range. Methods well known to the art can widen or narrow this hysteresis to meet the requirements of the particular application.

[0021] Some preferred embodiments of the invention would use a shaped memory alloy (SMA) motive element in its superelastic mode, and rely on the greater stiffness of the motive element as it is heated to act against the spring of the inner partition tube as otherwise described in the above example. As the stiffness of the superelastic motive element varies with temperature, the superlastic motive element would act in a manner similar to a thermally responsive bi-metal strip of a type that changes its shape in response to changes in temperature in a fairly linear fashion. Preferred embodiments of the invention can include superlastic or bi-metal strips for the motive element or a combination of both depending upon the particular requirements of the application.

[0022] A more technical explanation of the preferred embodiment described in the previous paragraph may be helpful for a more comprehensive understanding of the effect of the application or extraction of thermal energy on the motive element by the medium most proximal to it. In these preferred embodiments the motive element 9 is made of shape memory alloy (SMA), wherein the said motive element 9 is deformed by the spring of the flexible partition tube 5, normal to its longitudinal axis, from a previously memorized shape in a deformation state selected from one or more of bending, tension and torsion, and at a temperature at or above an austenite finish temperature of the SMA material such that the SMA material exhibits superelastic behavior by forming stress-induced martensite or exhibits pure elastic behavior, or some combination of both superelastic and elastic behavior in different areas or layers of the said motive element 9, and wherein the application of thermal energy, by the temperature of the medium 2 or 3 that is most proximal to it, causes the SMA material (the motive element 9) to increase in temperature, which causes the stiffness of the said motive element 9 to increase and thereby attempt to resume its memorized shape either by a concomitant increase in elastic modulus of the SMA material or by an increase in a value of a superelastic stress plateau, which is a stress at which the stress-induced martensite is first formed, or by a combination thereof, or other more complex deformation and recovery paths occurring as a function of stress, strain and temperature, including complex sub-loops at temperatures at or above the austenite finish temperature of the SMA material, and in attempting to resume its memorized shape overcomes or partly overcomes the said deformation by the spring of the flexible partition tube 5; and when energy is extracted from it by the temperature of the medium 2 or 4 that is most proximal to it, causes the said motive element 9 to relax and be partly or completely overcome by the spring of the flexible partition tube.

[0023] In some preferred embodiments the entire expanding and contracting flexible partition tube could be made of shape memory alloy, in which only that part of the partition tube that is relatively isolated from the other partition tube (the bellows 7) would undergo shape recovery or if superlastic stiffen and act as the motive element causing that flexible partition tube to expand or contract. In these preferred embodiments the flexible partition tube could be made springy as in the example above, that is tending to spring to its expanded or contracted shape.

[0024] Some preferred embodiments of the invention vary the shape of the cross-sections of the inner or outer partition tubes so that as the motive element acts against the spring of the flexible partition tube, contact or separation are made gradually, starting with a small patch and progressing normal to the longitudinal axis of the partition tube until in some situations most or all of the two partition tubes are fully contacting or fully separated along that section of partition tube. Preferred embodiments incorporating this feature would control the temperature in a more graduated manner. While the combination of shapes that would accomplish this type of preferred embodiment are many and once this invention is understood, could be applied by one skilled in the art, an example of such a arrangement would be one where the flexible partition tube has a slightly elliptical cross-section and the other partition tube has a cross-section that is round, sized in such a way that the spring of the flexible partition tube, acting in a plane normal to its longitudinal direction, would maintain, in this example, contact between the inner flexible partition tube and the other partition tube. As the motive element acts to pull the flexible partition tube away from the other partition tube it peals the flexible partition tube away from the other partition tube, a little at a time. This has the effect of gradually decreasing the heat being transferred across the two partition tubes and between the working medium and the product medium. Conversely when the motive element acts in an opposite direction, the heat being transferred increases gradually as contact increases between the two partition tubes.

[0025] In some cases the flexible partition tube is pressurized to an extent that it would cause the flexible partition tube to flex due to pressure rather than temperature change. In some preferred embodiments it is therefore necessary to include a pressure equalization means between the space in-between the two partition tubes; and the medium in the flexible partition tube that is for example inside the other partition tube. This can be simply a tube connecting the two spaces, or a tube running between the two locations with an intermediate chamber that includes a movable separator that segregates the media in the two areas, but at the same time moves in response to the pressure until the pressure in the flexible partition tube is equal to the space between the two partition tubes. In the case where the flexible partition tube envelopes the other partition tube, the equalization tube and intermediate chamber run between the space between the two partition tubes and the medium outside the flexible partition tube.

[0026] Some preferred embodiments of the invention include pressure relief means that allow the flexible partition tube to retract without creating a vacuum between it and the other partition tube and conversely, approach without creating a pressurization between it and the other partition tube. This is not usually a problem as the space between the tubes, even when retracted, is small. Means of relieving this vacuum or the pressure as the flexible partition tube recedes from or approaches the other partition tube can be a simple tube running from outside the heat exchanger into the space between the two partition tubes, or such other means as are well known to the art. Rather than have the pressure relief tube run out of the heat exchanger and accept ambient air, in other preferred embodiments the tube runs instead be attached to a gas supply to deliver a better insulating gas such as carbon dioxide. Carbon dioxide would be especially useful as it would provide an additional safety factor, if either medium was a combustible material, and because carbon dioxide has poor conductive and radiant transmissibility.

[0027] Other preferred embodiments do not have pressure relief means but instead take advantage of the vacuum that is created as the flexible partition tube retracts away from the other partition tube. These preferred embodiments maintain an airtight seal between the two partition tubes by means well known to the art. This vacuum of course reduces significantly the heat exchanged across the space created by the retracting flexible partition tube. These preferred embodiments require that the force exerted by the motive element(s) is strong enough to create and maintain a vacuum in the said space created by the retracting flexible partition tube. Since the partition tubes can retract or expand at different places along their length, it is sometimes necessary to provide flexible seals between them at various intervals along their length, that allow for deeper local vacuums at those places where they separate 6, unaffected by those areas where they do not separate. Some preferred embodiments include a vacuum being applied and maintained independently of the separation of the tubes which would include preloading a vacuum into the separation space, connecting the separation space 6 to a vacuum means, such as a vacuum pump or vessel or other means well known to the art.

[0028] Some preferred embodiments of the invention include means for reducing radiation between the two partition tubes. Some preferred embodiments therefore use thermally reflective surfaces on the facing surfaces of the two tubes. These coatings or treatments include chrome and nickel plating that is both reflective and thermally conductive when the two surfaces contact. The purpose of these non-radiating surfaces is to reduce heat transfer between the tubes where the two partition tubes are separated, but encourage heat transmission where the two partition tubes are in contact. The introduction of materials such as carbon dioxide, water vapor, carbon wool, fiber glass wool or a combination of such materials into the annular space between the two separated partition tubes also would reduce radiation, but would be relatively good thermal transmitters when the partition tubes were in contact and the materials were compressed or in the case of gases, expelled by the reduced space available. Carbon Dioxide would be particularly effective if the carbon dioxide was circulated through the said space, with cooling provided outside the tubes. In these cases when the two partition tubes contacted, the carbon dioxide would be pressed out of the area of contact, while the wool materials would be compressed, and would then allow conduction.

[0029] Some preferred embodiments of the invention include means for increasing the heat transfer between the motive element and the product medium in which the motive element is immersed or most proximal to the product medium. This can be accomplished by simply increasing the surface area of the motive element. This would include finning the motive element or texturing its surface.

[0030] Some preferred embodiments of the invention include means for further isolating the motive element of one flexible partition tube, in which it is attached or contained, from the temperature of the other partition tube. This is to ensure that the motive element is responding to the temperature of the medium in which it is immersed and not the temperature of the medium on the other side of the tubular partitions. For the preferred embodiments that place a flexible partition tube within the other partition tube, this isolation can be accomplished by the following methods: by moving the motive element to a central location within the flexible partition tube; and by using thermal insulation at those points where the motive element contacts the flexible partition tube and where the flexible partition tube might incidentally contact the other partition tube (to maintain their relative locations) when the two are otherwise separated.

[0031] Some preferred embodiments require that the working medium not transfer heat to or from the product if it is at a temperature in excess or below a certain threshold. For example, the outside partition tube might then be the flexible partition tube, with the motive element on the outside of the tube, immersed in the working medium. The flexible partition tube in this example would have a motive element arranged to reduce the radius of the tube and thereby contact the other partition tube containing inside the flexible partition tube's bore and containing the product, only when the working fluid is within the desired temperatures ranges.

[0032] Some preferred embodiments might require that both partition tubes be flexible, one being responsive to the medium inside the center tube and one being responsive to the medium outside the outside tube. Such an arrangement would allow heat transfer between the two media when both were at the desired temperature. This would be analogous to a Boolean “and” function. In such a case the inside and the outside partition tubes would only contact when the inside was expanded and the outside tube was contracted and the result of their meeting would allow thermal conduction from one medium to the other.

[0033] An “or” function could also be possible by allowing the two partition tubes to meet if either the outside partition tube contracted or the inside partition tube expanded. This “or” function requires that the preferred embodiment be designed so that the flexible means (bellows 7) in cooperation with the motive means 9 permit sufficient travel distance from the expanded to the contracted form so that contact between the partition tubes would occur if either the inside partition tube expanded or the outside partition tube contracted. By mixing the travel distance of the two tubes the various “and” “or” “both” functions could be realized to meet the requirements of the circumstances.

[0034] These preferred embodiments would be particular useful for the processing of organic materials which would be subject to deterioration if exposed to temperatures outside the desired range.

[0035] Other preferred embodiments of this invention would be useful where safety issues arise, for example boiler tubes or fuel tubes in nuclear reactors, or where fuel is preheated for efficient combustion, such as in a furnace or engine where waste gases or engine lubricating oil, engine manifolds or heads are used as a working medium to transfer heat to the product medium, the fuel. In these examples the fuel would typically be preheated by flue gases or the engine cylinder head or manifold but overheating would be potentially dangerous or denature the fuel, which could occur if the fuel moved to slowly or stopped in the fuel line and the heat of the flue gases or the engine continued. A preferred embodiment of the invention would put the fuel line in a flexible partition tube 5, which would line a fixed partition tube 3, and the motive element would be set so the flexible partition tube would contract when the fuel reached a certain maximum temperature. This would create a relative non-conducting space between the fixed and the flexible partition tubes and prevent further excessive heating of the fuel. A vacuum formed in the said space 6 by the contracting flexible partition tube would further isolate the fuel from the heat outside the fixed partition tube. As important as the foregoing, is the fact that the system will heat the fuel to an optimum temperature for combustion by transporting to the fuel line only so much energy as needed to accomplish the intended purpose.

[0036] Thermal storage would also be an application. For example exhaust gases from an engine might be stored in a working medium until it reached a certain temperature at which point it would be isolated from further heating. For example a section of the exhaust pipe could be formed from a flexible partition tube with its motive element immersed in the gas flow of the exhaust (the working medium). This section of flexible partition tube could pass through the bore of a second flexible partition tube, with its motive element immersed in a storage medium, external to the outside flexible partition tube. The motive elements and the geometry of the partition tubes is arranged so that the inner flexible partition tube expands to contact the outer flexible partition tube only when the exhaust gases reach a certain minimum temperature. The outer flexible partition tube will maintain contact with the inner flexible tube, while the inner partition tube is in its expanded contacting mode, until the storage medium reaches a certain maximum temperature at which point the outer flexible partition tube will separate from the inner flexible partition tube to prevent over-heating of the storage medium. When the storage medium drops below a predetermined temperature, it will again shrink in radius and seek to contact the inner flexible partition tube. Contact will resume between the two partition tubes unless the inner partition tube has itself retracted due to the engine exhaust gases being too cool (which might otherwise cool the working medium). The working medium in this example could be stored to pre-heat the catalytic heater for start-up, provide heat on start-up for the passengers, provide heat for batteries, fuels or fuel cells. While this example has been described in terms of an automobile use, it is to be understood that this invention can be used for many varied purposes for controlling the passage of heat across a heat exchanger.

[0037] Other preferred embodiments would be for the regulation of cooling in engines. There would be no need for a thermostat if the radiator's fins were constructed of fixed tube and flexible tube combinations designed to separate at the optimum operating temperature of the engine. In this case the coolant could flow continuously into the engine, without the necessity of a conventional thermostat. In this case, the coolant temperature would be very homogeneous, and not have the temperature swings that are normal with conventional thermostats.

[0038] Other preferred embodiments of this invention can isolate the product medium that would otherwise overheat, when for example, circulation pumps driving it through a heat exchanger fail. Controllable partition tubes as described above can virtually isolate the working medium from the product automatically and passively without recourse to electronic means, conventional valves or mechanical systems.

[0039] This invention should also be useful to protect heat transfer tubes from thermal damage. In this application, an expanding partition tube might contain in its bore a costly high pressure tube which it could protect from thermal shocks or thermal effects.

[0040] Another advantage afforded by the invention is that provided the partition tubes in the heat-exchanger are of sufficient length to always heat or cool the product to the desired temperature, no means to vary the velocity of the product is required to regulate its temperature.

[0041] Additional features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of the preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The detailed description particularly refers to the accompanying figures in which:

[0043] FIG. 1a is a cross-sectional view of a heat exchanger comprised of a container 1 that contains medium 2 through which two partition tubes run: one lining the other's bore, the inner 5 partition tube being flexible and containing a second medium 4 and the outer one, a fixed partition tube 3. The cross-sectional view of the said tubes being normal to the longitudinal axis of the said tubes 3 and 5. FIG. 1a illustrates the flexible tube 5 in its contracted form that produces an insulating space 6 between the flexible tube 5 and the fixed tube 3.

[0044] FIG. 1b is a cross-sectional view of that part of the heat exchanger illustrated in FIG. 1a that illustrates the flexible partition tube 5 in its expanded form and consequently contacting the inside wall of the fixed tube 3 in which it runs, thereby increasing the thermal conductivity between the medium 2 and the said second medium 4.

[0045] FIGS. 2a, 2b and 2c are cross-sectional views, parallel to the longitudinal axis of the partition tubes 3 and 5. These diagrams illustrates how the flexible partition tube 5 located inside the bore of the fixed partition tube 3, retracts away from the said fixed tube 3 as its motive element responds to the changing temperature of the medium 4 inside the bore of the flexible partition tube 5, as the said medium 4 moves from left to right; the said medium 4 having its temperature changed by the medium 2 outside the two partition tubes, 3, 5.

[0046] FIG. 2a illustrates the system when the two partition tubes 3, 5 are fully contacting 6a;

[0047] FIG. 2b illustrates when the two said tubes 3, 5 are separated over part of their length 6b and

[0048] FIG. 2c illustrates the two said tubes when they are separated over virtually their full length 6c.

[0049] FIGS. 2a, 2b and 2c also illustrate the relief passage tube 11 that is included in some preferred embodiments, in this case running between medium 2 and the space 6 between the two partition tubes 3, 5.

[0050] FIG. 3 is a cross-sectional view, parallel to the longitudinal axis of the partition tubes 3, 5 that illustrates a pressure equalization means 12 to eliminate the pressure of the medium 4 in the bore of the center flexible partition tube 5, thereby allowing the said flexible partition tube 5 to respond to the temperature in the tube by expanding and contracting, unaffected by the said pressure, which might otherwise expand or contract flexible partition tube 5. In this illustration the center flexible partition tube 5 is shown to have almost completely contracted, forming an insulating space 6 between the center partition tube 5 and the outside partition tube 3. The pressure is equalized in this case between the insulating space so created 6 and the medium 4 in the bore of the center flexible partition tube 5.

[0051] FIGS. 4a and 4b illustrate a preferred embodiment which is the converse of a preferred embodiment illustrated in FIGS. 1a and 1b. In this case the outside tube is the flexible partition tube 5 and the inside tube is fixed partition tube 3.

[0052] FIGS. 5a and 5b illustrate a preferred embodiment in which the fixed partition tube 3 lines the bore of a flexible partition tube 5 and is in turn lined by a flexible partition tube 5a.

[0053] FIG. 5a illustrates a case in which the medium 4 inside the bore of the inside flexible partition tube 5a has caused the inside flexible partition tube 5 to expand and to thereby contact the fixed tube 3, leaving no space between them 6d; but the outside flexible partition tube 5, responding to the temperature of the medium 2 outside the outside flexible partition tube 5 has expanded away from the fixed tube 3 leaving a space 6. FIG. 5b illustrates the case where the outside flexible partition tube 5, responding to the temperature of the medium 2 outside the outside flexible partition tube 5 has contracted and contacted the fixed tube 3; but the flexible partition tube 5a responding to the temperature of the medium 4 inside the bore of the said flexible partition tube 5a has contracted forming a space 6d between fixed partition tube 3 and flexible partition tube 5a.

[0054] FIGS. 6a and 6b illustrate a preferred embodiment of the invention which is comprised of two flexible partition tubes 5, 5a, in which 5a lines 5 but without a separating fixed partition tube as illustrated in FIGS. 5a and 5b, above. The medium 2 being outside the outside flexible partition tube 5 and the medium 4 being inside the bore of the inside flexible partition tube 5a, together with a double or “dog bone” T-rail 8.

[0055] FIG. 6a illustrates the case in which the medium 4 inside the bore of the inside flexible partition tube 5a has caused the inside flexible partition tube 5 to contract thereby causing the said partition tube 5a to withdraw away from partition tube 5; but flexible partition tube 5 has expanded and has withdrawn from flexible partition tube 5a.

[0056] FIG. 6b illustrates the case in which the medium 2 on the outside of the flexible partition tube 5 has caused the said flexible partition tube 5 to contract thereby contacting with flexible partition tube 5a. The inside flexible partition tube 5a continues to be in its contracted form, but due to the design of the arrangement, contact still occurs between flexible partition tube 5 and flexible partition tube 5a,

[0057] FIGS. 7a and 7b illustrate a preferred embodiment in which the motive element 9, rather than being attached to the bellows 7, crosses approximately the center of the flexible partition tube 5.

[0058] FIG. 7a and FIG. 7b also illustrates the use of insulation 18 at the interface of the motive element 9 and the flexible partition tube 5 to further isolate the motive element 9 from the temperature of the fixed tube 3 surrounding the flexible tube 5. The container 1 and medium 2 surround the detail illustrated in FIGS. 7a and 7b in a similar fashion to FIGS. 1a and 1b and have been omitted from the detail for diagrammatic clarity.

[0059] FIGS. 8a and 8b illustrate a preferred embodiment with positioning heals 19 that also act to thermally isolate the flexible partition tube 5 from the temperature of the surrounding fixed partition tube 3. The container 1 and medium 2 surround the detail illustrated in FIGS. 8a and 8b in a similar fashion to FIGS. 1a and 1b and have been omitted from the detail for diagrammatic clarity.

[0060] FIGS. 9a and 9b illustrate a preferred embodiment that has bellows 7 and a conforming motive element 9 that has greater surface area in order to more be responsive to the temperature of the medium in which it is immersed (not shown for diagrammatic simplicity). The container 1 and medium 2 surround the detail illustrated in FIGS. 9a and 9b in a similar fashion to FIGS. 1a and 1b and have been omitted from the detail for diagrammatic clarity.

[0061] FIG. 10 illustrates the details of a preferred embodiment with a bellow 7 with insulating patches that insulate 20, 21 the attached motive element from the thermal effects of the surrounding flexible partition tube 5.

[0062] FIG. 10 also illustrates a motive element 9 with fins 22 attached to increase its surface area for the purpose of making it more responsive to the temperature of the medium 4 in which it is immersed (not shown for diagrammatic simplicity).

[0063] FIG. 10 also shows the method by which the shape of the T-rail 8 controls the movement of the flexible partition tube 5 and ensures that when fully withdrawn from either the other flexible partition tube 5 or the fixed partition tube 3, that it does not at any point contact the other flexible partition tube or the fixed partition tube. The container 1 and medium 2 surround the detail illustrated in FIGS. 10a and 10b in a similar fashion to FIGS. 1a and 1b, along with other details have been omitted from the detail for diagrammatic clarity.

[0064] FIG. 11 illustrates a preferred embodiment in which the motive element 9 is connected to the flexible partition tube 5 on the inside of the bellow 7.

[0065] FIGS. 12a, 12b, 12c, illustrates a similar heat exchanger unit as illustrated in FIGS. 2a, 2b, and 2c, except that the outside flexible partition tube 5 has been substituted for a fixed partition tube 3. The said unit is then similar to those illustrated in FIGS. 7a and 7b, that is there are two flexible partition tubes.

[0066] FIGS. 13a and 13b illustrate a similar heat exchanger to FIGS. 1a and 1b, except the tubes are attached to the container 1 at only one end, and the opposite end of the tube is closed off; and the T-rail 8, bellow 7 combination runs annularly, normal to the longitudinal axis of their respective partition tubes: fixed partition tube 3 and flexible partition tube 5.

DESCRIPTION

[0067] FIG. 1a and FIG. 1b illustrate a cross-sectional view of a heat exchanger comprised of an outside container 1 which holds a medium 2. Through the container 1 runs a partition tube 3. This partition tube is attached at both ends to the tank 1, though which it passes to a supply or return. Normally a second medium 4 would pass through the bore of the partition tube 3 and there would be an uninterrupted flow of heat through the said partition tube 3, between the two media streams 2 and 4. This preferred embodiment however contains the medium 4 within a second partition tube 5 which is flexible radially and normal to its longitudinal axis. In this preferred embodiment the flexibility of the tube is due to two bellows 7. In this preferred embodiment there are two bellows, but it is to be understood that there may by any number of bellows in other preferred embodiments of the invention. These are only illustrative of the many methods, well known to the art, of allowing a member to be flexible and to contract and expand radially and normal to its longitudinal axis. In some preferred embodiments of the invention, the bellows and the T-rails, can run straight, parallel to the longitudinal axis of the tube, or they could spiral around the tube. The tube can be springy so that it is normally in its compressed form or in its expanded form, or it may not be spring at all. FIG. 1a illustrates the flexible partition tube 5 in its compressed form that causes a space 6 to form between it and the fixed partition tube 3 that surrounds it. FIG. 1b illustrates the flexible partition tube 5 in its expanded form that causes the space 6 to disappear and direct contact or contacting to occur between the inside walls of the fixed partition tube 3 with the outside walls of the flexible partition tube 5. When the space 6 exists between the tube walls, as illustrated in FIG. 1a, heat conduction between the two tubes is significantly reduced. This effect can be also be enhanced by coating the facing walls of the tubes with materials that reduce radiation across the space 6. When the space 6 disappears, as illustrated in FIG. 1b heat conduction between the two tubes is significantly greater than when the space exists.

[0068] The relative position of the tubes may, but need not be, aligned with T-rails 8 or other similar centering devices. These T-rails or centering devices will in most preferred embodiments be made of materials having poor thermal conductivity. In some cases these may not be necessary as illustrated in FIGS. 8a and 8b, where spurs on the bellows act to center the flexible tube, when in its contracted form. They may also not be necessary if the tubes ends are sufficiently supported by the container 1 to which they are attached, for example if the tubes have very short runs between the containers. The T-rails 8 illustrated in FIGS. 1a and 1b of a preferred embodiment have a tapered skirts 8b, narrow wastes 8c, to reduce thermal conductivity, and bulbous distal ends 8d that act in cooperation with the shape of the bellows 7 to center the flexible partition tube 5 relative to the fixed partition tube 3. This aspect of the invention is described in more detail in association with the detail drawing FIG. 10, below.

[0069] FIGS. 1a and 1b illustrate a motive element 9 that acts to expand and compress the flexible tube 5 as described above. This element can be anywhere in the medium 4 that is thermally isolated from the thermal effects of medium 2 and the fixed partition tube 3. In the preferred embodiment illustrated in FIGS. 1a and 1b the motive element is attached to the bellows and might include thermal insulation at the point of attachment, as later illustrated in FIG. 10. Another preferred embodiment illustrated in FIG. 11 would place the motive element 9 on the other side of the bellow 7, interfacing with the T-rail 8, which would be easier to fabricate, but separated from the medium 4 by the bellows 7. In another preferred embodiment the motive element can also run through the bulk of the medium 4 as illustrated in FIGS. 7a and 7b.

[0070] This motive element can be any material that changes shape in response to temperature change. The sizing and selection of materials will depend upon the exigencies of the application. The materials and methods used for this purpose are well known to the art and include thermally activated bi-metals and plastics and shape memory alloys (SMA's). The considerations for choosing a particular material or design of motive element or elements will include the temperature at which they will cause the flexible tube to contract or expand, whether it will do so in a linear or non-linear manner, whether it will react to a specific temperature or a range of temperature. As described above, shape memory alloys such as nickel-titanium are well suited, due to hysteresis, to allowing a range of temperatures to prevail before the motive element causes the flexible tube to expand or contract. Bi-metal strips on the other hand are cheap and reliable, their properties well understood.

[0071] In most cases the flexible partition tube 5 will be either sprung to contact the fixed partition tube 3 and in some cases the other flexible partition tube 5a (as shown on FIGS. 6a and 6b) or sprung to withdraw from the said other tubes. The bellow 7 is springy and causes the flexible partition tube 5 to expand or contract, depending upon the direction of the spring chosen for the particular preferred embodiment. The motive element 9 may act in one direction, opposite to the direction of the sprung bellow 7 or in both directions, in some cases acting with the spring and sometimes acting against it. The direction of the spring in the bellow 7, and of the motive element 9 will depend upon the circumstances and of the type of motive element 9 chosen. The parts of the flexible partition tube 5, other than the bellow 7, may also be sprung to conform to the shape of the fixed partition tube 3 or to the other flexible partition tube 5 when the said tubes are contacting.

[0072] It is important to note that in the heat exchange valve illustrated in FIGS. 1a and 1b it is not important whether medium 2 is the working medium or the product (medium 4 being the complement of either). Also the media need not be a fluid, but can be a gas or solid or other any other state or combination of states.

[0073] It is also important to note that the contraction and expansion of the flexible partition tube 5 is dependent on the temperature of the medium that acts on the motive element 9 at each point of that tube. This is the most important feature of the invention. This is illustrated in FIGS. 2a, 2b and 2c which are cross-sectional views of a preferred embodiment similar to that illustrated in FIGS. 1a and 1b, except that they are parallel to the longitudinal direction of the partition tubes. However, this aspect of the invention applies to all the preferred embodiments described herein.

[0074] In the preferred embodiment illustrated in FIG. 2a, the medium 4 is moving from left to right 10 through the bore of the flexible partition tube 5 and is being heated by medium 2a (in this case a gas flame) acting on the fixed partition tube 3. Initially (as illustrated in FIG. 2a), the medium 4 at no point along its passage, through the bore of flexible partition tube 5, does it cause the said tube to change from its expanded form to its contracted form. Heat then moves by conduction through the two partition tubes 3 and 5 to heat medium 4 at every point along its path through the said flexible partition tube 5. FIG. 2b illustrates the situation where the temperature of medium 4 rises further, where it causes the flexible partition tube 5 to retract away from the fixed partition tube 3 at and only at those places where the medium 4 has achieved sufficient temperature to cause such contraction. If the temperature of medium 4 continues to rise, it may exceed the desired temperature at vitually all points along the bore of flexible partition 5, perhaps constituting a dangerous condition. This might arise if the flow of the medium 4 stops 10a, but the flames of medium 2a continue. In such a case the entire flexible tube 5 might retract away from the fixed partition tube 3 leaving a space at virtually all points between them. This would have the effect of significantly reducing convection heating from medium 2a to medium 4. When medium 4 later cools below a predetermined temperature, the flexible partition tube 5 would again maintain contact with the fixed partition tube 3, but only along those parts of the tube where the temperature has dropped sufficiently. This is then a dynamic process in which the temperature is maintained within predetermined limits at every point along the partition tubes.

[0075] While in FIGS. 2a, 2b and 2c the tubes both are attached to the container 1, there being a separate supply and exhaust route for each separate stream of media, there may be preferred embodiments where one or other of the tubes are not so attached, but connected to each other by a flexible or fixed gusset. For purposes of this disclosure, the preferred embodiments that are described in cross-sectional view, normal to the longitudinal axis of the flexible partition tube and other tube or tubes that line or are lined by each other and form the heat exchanger, including those illustrated in FIG. 1, to 9, could be thought to have similar means of supply and exhaust in combination with a container 1, as that arrangement illustrated in FIGS. 2a, 2b and 2c; although in practice these will vary in accordance with the various circumstances to which the invention is put.

[0076] It is important to note that as the flexible partition tube 5 retracts away from the partition tube 3, if the tubes are air-tight and the force of the motive element is sufficiently strong, a vacuum will develop in the air space between the said tubes. This vacuum will greatly reduce the transfer of heat between the said tubes and if the separation exists along the entire length of the tubes, will create a virtual vacuum envelope. If in addition to the vacuum so created, the facing surfaces of the said tubes were finished with low radiation materials the heat transfer would be further reduced. If on the other hand the vacuum so created is not desirable for the purpose, a pressure relief passage 11 as illustrated in FIGS. 2a, 2b, and 2c, may, for example, pass through the fixed partition tube 3 or the container 1, connecting the space between the said tubes with ambient air outside the tubes or medium 2a. In other preferred embodiments, rather than supply ambient air, the said tube delivers gases that have higher insulative values such as argon or carbon dioxide.

[0077] The pressure of the medium in the flexible partition tube 5, might in some applications of the invention overcome the strength of the motive element to maintain normal operation of the flexible partition tube 5. For example, the said pressure might force the tube into its fully expanded form even though the motive element would be acting to maintain it in its retracted form. FIG. 3 illustrates a preferred embodiment that includes a pressure balancing means. This is only illustrative of methods of pressure control well known to the art and these will vary upon the application of the preferred embodiments of the invention and the relative locations of the fixed and flexible partition tubes. FIG. 3 includes a pressure balancing chamber 12 that includes a diaphragm 13 that acts to segregate the medium 2 and medium 4. Connecting tube 14a accesses medium 4 through the container 1 and Connecting tube 14b accesses the space 6 through medium 2, and fixed partition tube 3.

[0078] FIGS. 4a and 4b illustrate a similar preferred embodiment as that illustrated in FIGS. 1a and 1b, except that the fixed partition tube 3 is inside the bore of the flexible partition tube 5. The motive means and bellows are actuated now by medium 2 rather than medium 4. It acts in the preferred embodiment illustrated in FIGS. 1a and 1b. FIG. 4a illustrated the situation where the temperature of medium 2, at this particular point, causes the motive element 9 to permit or in turn cause the flexible partition tube 5 to retract away from the fixed partition tube 3, and thereby reduce thermal conduction across the said partition tubes and between medium 2 and medium 4.

[0079] FIGS. 4a and 4b also illustrates other features of a preferred embodiment that can be applied to any embodiment of the invention. The first is the shaping of the two partition tubes so that they incrementally contact and incrementally separate in response to the changing temperature of the media, in this example, medium 2. In the preferred embodiment illustrated in FIGS. 4a and 4b, the flexible partition tube 5 has been made slightly elliptical relative to fixed partition tube 3. FIG. 4a illustrates the two said tubes at an intermediate point where they are contacting at only contact area 15. At all other places between the two said tubes the there is still a space 6 that is tapered from the bellows 7 to the said point of contact 15. This tapering allows the two said tubes to incrementally contact and separate as the motive element 9 either contracts or spreads apart. It is to be understood that many different complementary shapes could be chosen to effect the same purpose, while still coming within the scope of the invention. The second feature that can be applied to any embodiment of the invention are separations 16 in the flexible partition tube 5. This separation allows the flexible partition tube 5 to be assembled around the fixed separation tube 3. Motive element 9, in this case snaps the two segments of the flexible partition tube 5 together to form a single tube. The sectioning of the flexible partition tube 5 and the means of doing so are merely illustrative of method well known to the art, and any of these could be used, while still coming within the scope of the invention. It should be noted that in some preferred embodiments of the invention, the fixed partition tube 3 might also be sectioned in a similar manner for ease of installation. FIGS. 4a and 4b also illustrate a method of further isolated the motive element 9 from the bellows 7, the flexible partition tube 5 and the fixed partition tube 3. In this preferred embodiment the motive element 9 is separated by a space 17 from most of the bellows 7. The motive element is also pushed out further into the bulk of the medium 2, where it more accurately can respond to the thermal effects of that medium 2 and less to the thermal effects of the fixed partition tube 3 and the medium which it contains 2. This space can of course be replaced with insulation to further improve the isolating effect mentioned above. This aspect of this preferred embodiment can be applied to the other preferred embodiments if convenient.

[0080] FIGS. 5a and 5b illustrate a preferred embodiment of the invention that includes two flexible partition tubes 5 and 5a, fixed partition tube 3 lining said flexible partition tube 5 and flexible partition tube 5a in turn lining said fixed partition tube 3. This preferred embodiment illustrates a combination of the principal elements of the invention that require that both flexible partition tubes 5 and 5a come into contact with the fixed partition tube 3 before conduction between media 2 and 4 is significantly increased. The motive elements 9 and 9a can have the same or different temperatures at which they change shape and cause them to pinch or release the bellows. The motive elements 9 and 9a can pinch or release at different rates and can act in the same direction or opposite to each other as the temperature rises and falls, that is they can both pinch as the temperature rises or one can pinch and the other release. As in all the illustrations herein, and as noted above, the number of bellows 7 in the flexible partition tubes 5, 5a and the corresponding number of aligning T-rails 8 can vary in number and location around the perimeter of the said flexible partition tube 5 and 5a in different preferred embodiments of the invention, depending upon the circumstances of the use to which the device is put.

[0081] FIG. 5a illustrates a preferred embodiment of the invention where the outside flexible partition tube 5 has withdrawn from the fixed partition tube 3 creating a space 6 which acts to reduce conduction between the media 2 and 4. This is the case even though flexible partition tube 5a has expanded contacting the fixed partition tube 3 and eliminated the space 6a between the said flexible partition tube 5a and the fixed partition tube 3. FIG. 5b illustrates the case where the outside flexible partition tube 5, responding to the temperature of the medium 2 outside the outside flexible partition tube 5 has contracted and contacted the fixed tube 3; but the flexible partition tube 5a responding to the temperature of the medium 4 inside the bore of the said flexible partition tube 5a has contracted forming a space 6d between fixed partition tube 3 and flexible partition tube 5a.

[0082] FIGS. 5a and 5b also illustrate how the shape of flexible partition tube 5 is controlled by the temperature of medium 2 in cooperation with the motive element 9 by the same means described above. FIGS. 5a and 5b similarly illustrates how the shape of flexible partition tube 5a is controlled by the temperature of medium 4 in cooperation with the motive element 9a, by the same means as described above.

[0083] FIGS. 6a and 6b illustrate a preferred embodiment that is similar to 5a in function but that does not include a fixed partition tube. It however does include two flexible partition tubes 5 and 5a that independently advance to contact the other or withdraw from the other to maintain a separation. This preferred embodiment has a double alignment T-rail 8 shaped like a “dog bone” which may also have one or more spurs 8a that assist in controlling the position of the said T-rail 8 in relation to the bellows 7 and 7a. FIG. 6a illustrates the case where the inside flexible partition tube 5a, responding to the temperature of medium 4, which causes the motive element 9a to pinch the bellows 7a, which in turn causes the flexible partition tube 5a to retreat from the outside flexible partition tube 5. But since flexible partition tube 5, responding to the temperature of the medium 2 in which it's motive element 9 is immersed, has expanded and moved away from the inside flexible partition 5a a space 6 separates the two said flexible partition tubes 5, 3. Thermal conduction between medium 4 and 2, is interrupted by space 6.

[0084] In the preferred embodiment illustrated in FIGS. 6a and 6b thermal transfer between medium 2 and medium 4 will occur when of course both flexible partition tubes 5, 5a contact. Assuming the said two flexible partition tubes 5, 5a are not in contact initially, contact between them will occur in this case when either flexible partition tube 5 contracts; or when flexible partition tube 5a expands due to thermal changes in media 2 and 4 respectively acting on motive elements 9 and 9a respectively.

[0085] The case illustrated in FIG. 6b eliminates the space which enhances heat transfer, but it should be noted that the flexible partition tube 5a is in its compact form. Should it in response to the temperature of medium 4 in which its motive element 9a is immersed expand, it would exert an additional force contacting the surrounding flexible partition tube 5.

[0086] It however should be clear that the length of the double alignment T-rail 8, the initial separation 6, the choice of motive elements and bellow 7 geometry principally govern the distance that each flexible partition tube 5 and 5a travel toward each other or away from each other in response to changes in temperature of their respective media 2 and 4. By combining flexible partition tubes with these different attributes and others, it is possible to design preferred embodiments of the invention that increase and decrease conduction through the two flexible partition tubes 5 and 5a and between media 2 and 4 in many different ways. For example, by lengthening the part of the double alignment T-rail 8, along its longitudinal axis, that engages bellows 7, flexible partition tube 5a could be made to contact only the contracted form of flexible partition tube 5, rather than the expanded form as well, as illustrated in FIGS. 5a and 5b.

[0087] The combinations possible are many when the various factors are modified, for example the rates at which the tubes advance or retreat from each other are also varied, by varying the motive element 9 and 9a and bellows 7, 7a geometry and the T-rail 8, 8a geometry. The choice of which combination to use will depend upon the requirements of the particular embodiment. This feature of the invention makes it a very powerful means to control the transfer of heat to or from various media, passively without resort to electrical controls and valves.

[0088] FIGS. 7a and 7b illustrate a preferred embodiment of the invention that uses a single motive element that crosses the bore of the flexible tube 5. This illustrates the fact that any number of motive elements can be used, to control the shape of the flexible partition tube or tubes used in the preferred embodiments of the invention and also that their position in relation to the flexible partition tube can vary without departing from the substance of the invention. Like all other motive elements used in preferred embodiments of the invention the element may be one continuous element, running through the length of the bore of the flexible partition tube, both their longitudinal axis approximately parallel to each other, or be discontinuous and made up of discrete sections, controlling only stretches of the tube. The preferred embodiment illustrated in FIGS. 7a and 7b has the advantage of being thermally responsive to the bulk of the medium 4, rather than to the medium located around the periphery of the bore of flexible partition tube 5, where edge effects may not represent the condition of the bulk of the medium contained in the bore of the said tube. Isolation of the motive element 9b from the thermal effects of the fixed partition tube 3 and the medium outside the fixed partition tube (not shown) may, but need not be, enhanced with a layer of insulating material 18 between the ends of the said motive element 9b and the flexible partition tube 5. A further advantage of using the single motive element 9b as illustrated in FIGS. 7 and 7b is that it acts as a baffle which, if it is helical along its longitudinal axis, will increase turbulence in the medium traveling down the bore of the said flexible partition tube and thereby enhance heat transfer.

[0089] The preferred embodiment illustrated in FIGS. 7a and 7b works in the same manner as that described for FIGS. 1a and 1b above, except that the motive element is singular and has been enlarged and moved out into the center of medium. Temperature changes in the medium 4 cause the motive element 9b to change shape, either pushing the walls of the flexible partition tube 5 against the walls of the fixed partition tube 3 or pulling the said walls of the flexible partition tube 5 away from the said fixed tube 3, and thereby increasing heat transfer between the two tube or reducing it, respectively. In the preferred embodiments this motive element being made of a material that changes shape in response to temperature changes, and includes thermally activated bi-metal strips, shape memory alloy (SMA) and other materials that exhibit this property. This preferred embodiment illustrates that the position and number of motive elements can be varied without departing from the principal concepts of the invention. The container 1 and medium 2 surround the detail illustrated in FIGS. 7a and 7b in a similar fashion to FIGS. 1a and 1b and have been omitted from the detail for diagrammatic clarity

[0090] FIGS. 8a and 8b illustrate a preferred embodiment that uses spurs shaped turns on the bellows 19 to ensure separation between the flexible partition tube 5 and the fixed partition tube 3. As will all preferred embodiments, the number and position of the bellows 7 around the perimeter of the flexible partition tube can be varied depending upon the circumstances of its application. One preferred embodiment would include three, bellow 7 and motive element 9 combinations. Otherwise this preferred embodiment illustrated in FIGS. 8a and 8b works in the same manner as that described for FIGS. 1a and 1b, above. The tips of the spurs 19 may have insulation attached to their ends; or attached to the inside of the tube where the spurs 19 contact the inner walls of, in this case the fixed partition wall 3, as illustrated 20 in FIG. 10, or both. The spurs 19 may very in size along the length of said flexible partition tube 5 so that they only contact the inside walls of, in preferred embodiment the fixed partition 3, intermittently, while the said flexible partition tube 5 is in its contracted form as illustrated in FIG. 8a., thereby reducing the contact surface area when the spurs are in contact with the inside of the other partition tube. It should be noted that the spurs 12 illustrated in FIG. 8a are pressed out by the pinching action of the motive element 9 in cooperation with the bellows 7. FIG. 8b illustrates the spurs retraction, when the pinching action is relieved and the spur retracts and retreats away from the inside wall of fixed partition tube 3. The container 1 and medium 2 surround the detail illustrated in FIGS. 8a and 8b in a similar fashion to FIGS. 1a and 1b and have been omitted from the detail for diagrammatic clarity. As is the case for all the preferred embodiments of the invention, the motive element may be of any type and located anywhere in or on the flexible partition tube that will be thermally responsive to the media interfacing directly with that tube and cause the tube to expand or contract. A preferred embodiment of the invention is a flexible partition tube lined by another partition tube that utilizes spurs in same way as illustrated in FIGS. 8a and 8b, with the spurs 19 pointing inward, rather than outward, but otherwise functioning the same as those illustrated in FIGS. 8a and 8b. The preferred embodiment illustrated in FIGS. 8a and 8b, might therefore include a motive element similar to that 9b illustrated in FIGS. 7a and 7b in addition to or in substitution of the motive element 9 illustrated in FIGS. 8a and 8b.

[0091] The container 1 and medium 2 surround the detail illustrated in FIGS. 8a and 8b in a similar fashion to FIGS. 1a and 1b and have been omitted from the detail for diagrammatic clarity

[0092] FIGS. 9a and 9b illustrate a preferred embodiment that uses more folds in the bellows 7 and complementary folds in the motive element 9. The purpose is to increase the surface area of the motive element that interfaces with the medium 2 (not shown) that is external to the flexible partition tube 5 as well as to provide means for increasing the force that the motive element 9 can exert. The other purpose is to allow more movement of the flexible partition tube 5 between its expanded and contracted positions. Otherwise this preferred embodiment illustrated in FIGS. 8a and 8b works in the same manner as that described for FIGS. 4a and 4b above. This preferred embodiment also illustrates how the details of the bellows may vary without departing from the principal concepts of the invention.

[0093] The container 1 and medium 2 surround the detail illustrated in FIGS. 9a and 9b in a similar fashion to FIGS. 1a and 1b and have been omitted from the detail for diagrammatic clarity

[0094] FIG. 10 is a detail of the interaction of the aligning T-rail 8 and the bellows 7 of the flexible partition tube 5 of a preferred embodiment of the invention. In this preferred embodiment of the invention the geometry of the T-rail 8 and that part of the flexible partition tube 5 that interacts with it is shaped in such a way that the flexible partition tube is held away from the inside walls of the fixed partition tube, but restrained from being displaced too far away from the said fixed partition tube wall, when the said bellows 7 pinches said T-rail 8. When, for example, the outward spring of the flexible partition tube 5 presses the said flexible tube against the inside wall of the fixed partition tube 3, and there is virtually no space 6 between them, thermal conduction across the said two tubes is significant. As the temperature changes in the medium 4 contained within the flexible partition tube 5, the said bellows can be arranged to pinch the T-rail 8, due to the motive element pinching the said bellows 7. This pinching action causes the turns of the bellows to slide down the tapered ramp from the wide skirt 8b to the tapered waste 8c of the said T-rail 8. Further movement away from the wall is stopped by the enlarged bulb 8d of the T-rail. This stopping of further movement is of course important as this prevents the flexible partition tube from continuing to move across the bore of the fixed partition tube and contacting it at the opposite side. One, two, three or more of these T-rail 8 and bellow 7 combinations around the periphery of the flexible partition tube 5, will thus act to suspend the said tube away from the walls of the fixed partition tube in which it is located. When thus suspended the thermal heat transfer across the two said tubes will be significantly reduced by the space 6 that exists between them. Also, since the waste 8c can be very narrow, there can be very little thermal conduction through the said T-rail 8 that would affect the operation of the motive element 9 or heat the medium 4. As mentioned above this T-rail can also be made of a very low thermal conductive material, but even if it is fabricated as an integral part of the tube, the small cross-section of the waste 8c ensures a very low thermal transport through it. While FIG. 10 illustrates the method of controlling the movement of the flexible partition tube in relation to the fixed partition tube 3, it is to be understood that the same principals apply to the double T-rail 8 or “dog bone” T-rail illustrated in FIGS. 6a and 6b,

[0095] In those preferred embodiments where the fixed partition tube 3 lines the flexible partition tube 5, as illustrated in FIGS. 4a and 4b the alignment of the tubes when separated by a space 6 is provided mainly by the cooperation of the enlarged bulb 8d of the T-rail 8 and the bellows 7. When the said tubes in FIGS. 4a and 4b are contracting, the alignment is mainly provided by the cooperation of the T-rail 8 and the bellows 7, as well as the cooperation between the tubes contacting each other. The alignment of the tubes for most preferred embodiments will be improved by adding more T-rail 8 and bellows 7 combinations to the systems, or other aligning means such as the spurs 19 illustrated in FIGS. 8a and 8b.

[0096] While FIG. 10 illustrates sections of tubes, it is to be understood that the T-rail 8 and bellows 7 and motive element 9 can be part of any vessel shape, where the interaction between the said T-rail 8 of that shape described in FIG. 10 and the said bellows 7 in cooperation with the motive element 9 responding to the temperature of medium in which motive element 9 is immersed, causes the vessels to contact, enhancing thermal conduction; or separate reducing thermal conduction.

[0097] FIG. 10 also details some methods of further isolating the motive element 9 from the thermal effects of the fixed partition wall 3 and the T-rail 8. Insulation 20 can be placed at various places, well known to the art, that thermally isolate the motive element 9. In addition a flexible insulation 21 might be placed in the hollow of the bellows to reduce convection and insulate the interfacing surfaces of T-rail 8 and bellows 7. The insulation 20 between the motive element 9 and the bellows 7 would further isolate the motive element 9 from the thermal effects of the fixed partition wall 3. Instead of insulation one might include a space 17 for some of the interfacial area between T-rail 8 and bellows 7, for that preferred embodiment illustrated in FIG. 4, above.

[0098] A preferred embodiment, illustrated in FIG. 10 also includes fins 22 attached to the motive element 9, but these of course could be an integral part of the motive element 9. These fins 22 make the said motive element more responsive to medium 4 (not shown for diagrammatic simplicity) in which the said motive element is immersed as illustrated in FIG. 1 and 1b.

[0099] FIG. 11 illustrates a preferred embodiment in which the motive element 9 is located within the fold of the bellows 7. This preferred embodiment is in some cases easier to fabricate that those preferred embodiments where the motive element 9 is inside the flexible partition tube 5. While this arrangement places the motive element on the other side of the bellows 7 where it is not in direct contact with the medium, the temperature of which it is supposed to react, it is still relatively isolated from the other medium by the narrow neck of the bellows 7 and by the T-rail, which is in some preferred embodiments made of a material that acts as a thermal insulator.

[0100] FIGS. 12a, 12b, 12c, illustrates a similar heat exchanger unit as illustrated in FIGS. 2a, 2b, and 2c, except that the outside flexible partition tube 5 has been substituted for a fixed partition tube 3. The said unit is then similar to those illustrated in FIGS. 7a and 7b, that is there are two flexible partition tubes, one loaded into the other's bore. It is to be understood that the following is an example of only a few uses to which the preferred embodiment might be put. An example of a preferred embodiment of the invention would be a heat exchanger to heat medium 4 contacting the outside tube wall of flexible partition tube 5, the product medium in this example, the source of the heating being medium 2a which is located in the bore of flexible partition tube 5a, the working medium. The preferred embodiment could for example be used to store heat from the exhaust pipe of an engine and then use that heat later to heat the car, catalytic converter, or battery for cold start-up or for maintenance of batter charge. For such a preferred embodiment, FIG. 12a would illustrate the preferred embodiment of the invention when the engine exhaust stream 2a had not yet heated up the flexible partition tube 5a and it remains in its contracted shape, normal to its longitudinal axis. However, flexible partition tube 5 responding to the cooling temperatures of medium 4 assumes its contracted shape, normal to its longitudinal axis, seeking contact with said flexible partition tube 5a, but not making contact due to the contracted shape of said flexible partition tube 5a. This orientation permits separation between the two said flexible partition tubes 5 and 5a, and reduced transmission of heat between medium 4 through partition tube 5a. As described above, in some preferred embodiments a vacuum is caused by the separation of partition tubes and can be maintained by sealing the area between the said partition tubes 5 and 5a. Maintaining a vacuum between the said partition tubes 5 and 5a is one of many methods described earlier, any of which could be included in preferred embodiments of the invention, that would ensure that after a prolonged period of non-use, there is not excessive heat transfer back out of medium 4 through flexible partition tube 5. While it is possible to create a vacuum between the said partition tubes 5 and 5a in which case pressure relief ports 11 would be dispensed with, other conditions might be created as described above, for example, charging the vacant space with another gas, that reduces radiation such as carbon dioxide as the partitions separate. These materials that reduce radiation could be either circulated through ports 11 (as extended through medium 4) being cooled or heated as required, external to the system illustrated on FIGS. 12a and 12b or they could be simply allowed to enter and exit from an external supply in response to the changing pressure in the separation between the said flexible partition tubes 5 and 5a.

[0101] FIG. 12b illustrates the preferred embodiment when the exhaust from the engine, medium 2a, has heated the flexible partition tube in which it passes to expand into its expanded shape, normal to its longitudinal axis, and contact the flexible partition tube 5 while that tube is in its contracted state, normal to its longitudinal axis, and to thereby allow heat transfer to increase between medium 2a and heat storage medium 4.

[0102] FIG. 12c illustrates the preferred embodiment when the medium 4 had hit its maximum storage temperature and flexible partition tube 5 has assumed its expanded shape in response to the temperature in the medium, causing the said two flexible partition tubes to separate, and further heating of the said medium 4 to stop, even though flexible partition tube 5a is still in its expanded form, normal to its longitudinal axis, as it is still being sufficiently heated by medium 2a to maintain that shape.

[0103] It is important to note that while the above example has for simplicity described the flexible partition tubes 5 and 5a expanding and contracting in gross, preferred embodiments of this invention permit just part or parts of the said flexible partition tubes to expand and contract in response to the temperature of the medium that they are most proximate to, and thereby only transfer heat as required along those sections. In addition to the virtues of the invention described above, this has the virtue of uniformly maintaining the product at an optimal temperature, without hot spots or cold spots. While the preferred embodiment of the invention has been discussed in the context of the example of a heat storage device, it is to be understood that it could be used for many purposes to effect heat transfer, including cases where medium 2a, would be the product medium and medium 4 would be the working medium.

[0104] FIGS. 13a and 13b illustrate a similar heat exchanger to FIGS. 1a and 1b, except that fixed partition tube 3 and flexible partition tube 5: are attached to the container 1 at only one end, the opposite ends of the tubes are closed off; and the T-rail 8, bellow 7 combination runs annularly, normal to the longitudinal axis of their respective partition tubes, rather than longitudinally. This preferred embodiment is illustrative of the many preferred embodiments that derive from the invention while still being within its ambit. FIGS. 13a and 13b illustrate a container that can maintain the heat of the media 4 an optimum temperature. For example the container might be used in the kitchen for special cooking purposes such as heating sauces that require a temperature to be maintained within a narrow temperature range. For example, a preferred embodiment of this device set for a certain temperature range could be used instead of a double boiler, but one which would not require checking to see if the water has boiled away. It could also be used for safety purposes to prevent fire from overheating, especially where oils are heated. FIG. 13a illustrates a preferred embodiment where the motive element 9, responding to the temperature of media 4 causes the bellows 7 to contract, causing the inner flexible tube to contract longitudinally, and thereby pulling the end of the said tube 5c away from the end 3b of the fixed partition tube 3. This preferred embodiment would then retract the medium 4 at some chosen temperature, preset into the motive element 9, away from the thermal effects of medium 2a. In the preferred embodiment of the invention illustrated in FIGS. 13a and 13b, the end of the flexible partition tube 5 is rounded 5c and flexible to permit the flexible tube 5 to contact fixed tube 3 gradually, in the same manner as illustrated in 4a and 4b for another preferred embodiment of the invention. FIG. 13b illustrates a intermediate step between complete contact and complete separation of flexible partition tube 5 and fixed partition tube 3, where only part of the two partition tubes are contacting 5c, 3b and therefore the heat transfer between medium 2a and 4 is relatively slow. In other preferred embodiments the end 5c of the flexible partition tube 5 could be flat or another shape to give it different contact and separation characteristics. As for all other preferred embodiments of the invention, the methods described above for reducing radiant and convection heating could be applied to this preferred embodiment. This preferred embodiment particularly suites it for the maintenance of a vacuum between flexible partition tube 5 and fixed partition tube 3 when the end 5c of flexible tube 5 responding to higher temperatures in medium 4 contracts away from the end 3b of fixed partition tube 3, thereby increasing the volume of separation between the said partition tubes and because they are sealed, creates and maintains a vacuum. On manufacture or subsequently, the space between the tubes 6, like all other preferred embodiments of the invention, could have a vacuum applied by other means independent of the separation of the said partition tubes, such as using a vacuum pump to vacate the space and create a vacuum of various strengths, depending upon the use to which it is put. Other preferred embodiments of the invention might dispense with the T-rail 8, especially where the length of flexible partition tube 5 is short and alignment between the said flexible partition tube and the fixed partition tube would not be an issue. Other preferred embodiments would not have the separate container section 1, but would use a continuous piece to define both said fixed partition tube 3 and flexible partition tube 5, or connect the two tubes together by the usual means. But in other preferred embodiments the separate container section 1 would be retained and made of a material that had high insulative value to isolate the motive element 9 from the thermal effects of the fixed partition tube 3. While the preferred embodiment of the invention illustrated on FIGS. 13a and 13b places the flexible partition tube in the bore of the fixed partition tube, other preferred embodiments would have the opposite arrangement. And while the preferred embodiment illustrated in FIGS. 13a and 13b include only a fixed partition tube 3 and a flexible partition tube 5, other preferred embodiments would include two flexible partition tubes, one for each wall of the vessel, that would act in a similar manner to those devices described in association with FIGS. 7a and 7b, and 12a and 12b. Such a preferred embodiment of the invention would be a device for example that could be used for a pot that would maintain, for a longer period of time, the temperature of the medium 4 that was contained in the flexible partition tube 5, if the heat 2a was turned off.

[0105] It should be noted that the preferred embodiment of the invention described in FIGS. 13a and 13b is meant for illustrative purposes only and that the relative position and size of the features can be varies without departing from the substance of the invention. For example the bellows 7 and motive element 9 could be placed lower or higher along the longitudinal axis of flexible partition tube 5.

[0106] It should also be understood that while the examples of tubes referred to in this disclosure and in the drawings are cylindrical or elliptical, it is to be understood that tubes having a cylindrical cross-section are only examples of a larger class of tubes having many different cross-sectional geometries, for example, triangular, square or star-shaped a combination thereof as well as any conic section.

[0107] It should also be understood that while the examples of the invention describes the heat containing bodies as tubes, it is to be understood that these media containing vessels or media partitions can be any shape.

[0108] It should be understood that the examples of preferred embodiments described are not exhaustive and the partitions separating one medium from another, while always including a flexible thermal partition, may also include any number or type of other thermal partitions, including flexible and fixed that line or are lined by, or both, the first referred to flexible thermal partition.

[0109] It should be understood that the medium 2 and medium 4 can be any form of matter, in any phase including gas, liquid or solid or combination of each.

[0110] While this disclosure sometimes refers to the media as being a working media or a product, it is to be understood that in the heat exchanger illustrated in the diagrams, medium 2 can be either a working medium or the product, depending upon the use to which it is put, medium 4 being in each case the complement, although their function can switch from time to time as the state of the heat exchange valve changes.

[0111] While each of the preferred embodiments described in this patent include numerous particular features, it is to be understood that those same features may be added to those other preferred embodiments and conversely the preferred embodiments need not have some of those features described and still come within the ambit of the invention. For example the motive element 9b illustrated in FIG. 7a could be used in any of the other preferred embodiments in addition to or in lieu of the motive elements described in those preferred embodiments.

[0112] While the preferred embodiments are meant to illustrate clearly the principles of the patent, it is to be understood that the scale of the relative details will vary and the invention is not limited to the relative size of the individual details illustrated. For example the space 6 between the flexible partition tube 5 and the tube that lines it or that is lined by it, may differ in size relative to the size of the other details of the preferred embodiment, and the T-rail 8 and bellows 7 sizes and shapes will very depending upon the function that the particular heat valve is designed to perform.

[0113] While the present invention has been described in conjunction with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the inventions and appended claims.