JPS6213997A - Heat exchanger of panel type - Google Patents

Abstract

PURPOSE:To enable to provide a maintenance work for a heat exchanger very easily and conveniently, by constituting a reinforcement ring by bonding two rings into one body in the axial direction so that radial flow paths are formed between both rings. CONSTITUTION:A reinforcement ring 11 is constituted by laying two rings 11a, 11b, on which faces radial recesses 13a, 13b are provided, in the axial direction so that each recess 13a, 13b is faced to each other to form a radial flow path 13 respectively, and by tightening both rings into one body by connecting pins 11c. On the internal periphery of the ring 11, an annular groove 12 is provided. It is formed between both rings 11a, 11b and is communicated with the radial flow paths 13. A heat exchanger can easily be assembled by only fitting each hollow panel 1 and annular sealing 20 alternately to a fluid fed pipe 8 and a fluid discharge pipe 9 in the axial direction and by tightening those parts all together. The reinforcement ring 11 prevents both ends of plates of a hollow panel from bending to the inside by the tightened reaction. It also certainly holds the spaces between the fluid inlet part and the fluid outlet part of a hollow panel in a specified width, so that the primary fluid can be fed into the hollow panel 1 smoothly as it is initially designed.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention involves arranging a plurality of hollow panels for heat exchange in parallel at appropriate intervals and integrating them, and allowing a fluid for heat exchange to flow through each of these hollow panels. It is a panel type heat exchanger that is mainly used in a storage tank of a fluid to be heat exchanged or in a flow path of the fluid, and the fluid flowing through each hollow panel and each hollow The present invention relates to a dual panel heat exchanger that exchanges heat with a fluid located in a gap between panels or a fluid flowing through the gap.

(Prior art and its problems) The above-mentioned panel type heat exchanger includes a fluid supply pipe line and a fluid discharge pipe line that pass through each of a large number of hollow panels arranged in parallel in the parallel direction. , the fluid flowing through the fluid supply pipe is divided into each hollow panel, and the fluid flowing through a predetermined flow path in each hollow panel after heat exchange is merged into the fluid discharge pipe and discharged. However, in the conventional panel heat exchanger of this type, the fluid supply pipe and the discharge pipe were structured as follows.

That is, a short cylindrical body is fixedly protruded by welding from each of the through-holes provided oppositely to the plates on both sides forming each hollow panel, and the cylindrical body protruding from both panels is provided between adjacent hollow panels. By fitting the bodies into each other and firmly connecting both cylindrical bodies to each other by welding at this fitting location, a fluid supply conduit or a fluid discharge conduit passing through each hollow panel in the parallel direction is constructed. was.

In a conventional panel heat exchanger having such a configuration, a large number of hollow panels arranged in parallel are integrally integrated by the fluid supply pipe and the discharge pipe in a manner that cannot be disassembled. Generally, in this type of panel heat exchanger, the gap between each hollow panel is very narrow, around 20-1, so if it is not possible to separate each hollow panel from each other as described above, Even if scale from the fluid flowing through the gap adheres to the surface of the hollow panel, it is almost impossible to clean it out. Therefore, conventional panel-type heat exchangers are used only when the fluid flowing through the gaps between the hollow panels has almost no scale buildup, which greatly limits its applications. Ta.

On the other hand, in terms of manufacturing, as mentioned above, short cylindrical bodies must be fixed and protruded from each hollow panel on both sides by welding, and both cylindrical bodies must be fixedly protruded from each hollow panel in an extremely narrow space between two adjacent hollow panels. This method has the disadvantage that the manufacturing cost is increased due to the fact that the shaped bodies must be joined by welding.

In particular, it is impossible to manually weld the fitting part of both cylindrical bodies over the entire circumference within the extremely narrow space between two adjacent hollow panels as described above, and therefore a dedicated automatic welding machine is required. It was.

(Means for Solving the Problems) The present invention proposes a panel type heat exchanger that can solve the above conventional problems, and its feature is that two plates are placed between them. A through hole is provided through which a fluid supply pipe and a fluid discharge pipe pass through the heat exchange hollow panel which are joined to each other to form a flow path, and a through hole is provided between the two plates on both sides around the through hole. A required number of said hollow panels are interposed with a reinforcing ring having a radial flow path to prevent the gap between said both side plates from narrowing, and have a fluid supply pipe and a fluid discharge pipe provided with a flow hole on the outer periphery. of,
A panel heat exchanger in which an annular sealing material is fitted onto the fluid supply pipe and the discharge pipe between each hollow panel so that the pipe can be pulled out and disassembled in the axial direction of the pipe, and is fastened and integrated. The reinforcing ring is configured by integrating two annular bodies that are aligned in the axial direction so as to form the radial flow path between the two annular bodies.

(Function) In the configuration of the present invention as described above, the space around the fluid supply pipe and the discharge pipe is completely isolated from the outside world by each hollow panel and the annular sealing material between each hollow panel. ing. Therefore, the fluid supplied into the fluid supply pipe is divided into each hollow panel from the circulation hole in the pipe peripheral surface via the radial flow path of the reinforcing ring in each hollow panel, and then flows into each hollow panel. The fluid flowing through the flow path joins into the discharge pipe from the radial flow passage of the reinforcing ring located outside the fluid discharge pipe via the communication hole on the pipe peripheral surface.

Therefore, one fluid (the first fluid) of the two fluids that exchange heat with each other is supplied to the panel heat exchanger of the present invention, and the panel heat exchanger of the present invention is used to store the other second fluid. By setting it in the tank or in the flow path of the second fluid, the first fluid flowing in each hollow panel as described above and the gap between each hollow panel or the gap between the two. A predetermined heat exchange action can be performed between the fluid and the second fluid flowing therein.

Furthermore, when the hollow panels are tightened in the axial direction of the fluid supply pipe and the discharge pipe to integrate them, even if the annular sealing material between the hollow panels is sufficiently tightened to obtain the desired sealing effect, The reinforcing ring prevents the plates on both sides of each hollow panel from bending inward due to the reaction force of the tightening, so that a constant space can be secured for the fluid inlet and outlet of each hollow panel. Of course, by unfastening each hollow panel, each hollow panel and the annular sealing material can be pulled out in the axial direction from the fluid supply pipe and the discharge pipe, and separated from each other.

(Example) An example of the present invention will be described below based on the attached illustrative drawings.

In FIGS. 1 and 2, reference numeral 1 denotes a rectangular hollow panel for heat exchange, and a zigzag band-shaped flow path 3 is formed between two plates 2 on both sides of the flow path 3. Both plates 2 are integrally joined to each other by a seam welded portion 4. Although not shown in FIG. 2, both plates 2 are as shown in FIGS. 3 to 5.
Inside the flow path 3, four people are placed inside each in an appropriate shape, and both plates 2 are welded together at the spot welding part 6 in the recessed part 5.
By joining them together, it is possible to increase the strength of the panel 1, to make the cross-sectional area of the flow path 3 constant, and to make the fluid flowing in the flow path 3 turbulent, thereby improving heat exchange efficiency. Of course, the shape, length, and cross-sectional area of the flow path 3, or the arrangement, shape, and size of the recessed portion 5 may be set depending on the purpose of use of this heat exchanger, the type of fluid used, etc. , but not limited to what is shown.

The hollow panel 1 is provided with circular wide portions 7 formed by bulging both plates 2 outward at both ends of the flow path 3. A through hole 10 (see FIG. 6) for passing the fluid supply pipe 8 and fluid discharge pipe 9 shown in FIGS. 1 and 2 (see FIG. 6) is provided concentrically with the wide portion 7. And Figures 1 and 3
6, a reinforcing ring 11 having an inner diameter substantially equal to the diameter of the through hole 10 and an outer diameter substantially equal to the inner diameter of the wide portion 7 is sandwiched in the wide portion 7, as shown in FIG. There is. Since this reinforcing ring 11 is positioned concentrically with the through hole 10 by the wide portion 7, it is only necessary to fit it into the wide portion 7 of one plate 2 before joining the plates 2 on both sides. There is no particular need to fix it to the plate 2.

As shown in FIGS. 6 to 8, the reinforcing ring 11 includes two annular bodies 11a and llb each having radial recesses 13a and 13b on opposite sides, respectively, and the recesses 13a,
13b are stacked in the axial direction so as to face each other and form a radial flow passage 13, and are integrally connected by a connecting pin ttc.
a.

11b and is provided with an annular groove 12 that communicates with the radial flow passage 13. The coupling pin 11c may be fixed to the re-annular bodies 11a, 11b by caulking both ends, or may be fixed to the re-annular bodies 11a, 11b at both ends.

Of course, it is also possible to weld the re-annular bodies 11a and +1b together by means of a coupling means other than the coupling pin IIC.

The fluid supply pipe 8 and the discharge pipe 9 are connected through joint pipes 17 to the lower ends of a fluid supply main pipe 15 and a fluid discharge main pipe 16, respectively, which are attached to the support plate 14 in a penetrating state, as shown in FIGS. 1 and 2. The hollow panel 1 is fixedly protruded in a T-shape, and has a threaded portion 18 at the free end, and a slit-shaped communication hole 19 extending along the axial direction is provided in the mounting area of the hollow panel 1 in the circumferential direction. They are provided at multiple locations (four locations in the illustrated example).

A required number of the hollow panels 1 are arranged in parallel so that the fluid supply pipe 8 and the discharge pipe 9 pass through the through hole 10 of each wide portion 7. At this time, the joint pipe 17 and the adjacent hollow panel 1 and between each hollow panel 1 is an annular sealing material 2 that fits over the fluid supply pipe 8 and the discharge pipe 9.
0, and a backup ring 21 that fits around the annular sealing material 20 is interposed. Of course, the annular sealing material 20
and the backup ring 21 abut against the outer surface of the wide portion 7 of each hollow panel 1.

As described above, each hollow panel 1 connected in parallel to the fluid supply pipe 8 and the discharge pipe 9 has an annular sealing material 20 and a bank up ring 21 interposed between it and the outermost hollow panel 1. In this state, the fluid supply pipe 8 and the discharge pipe 9 are fastened and integrated in the axial direction by tightening the NANDs 22 screwed into the free end threaded portions 18 of the fluid supply pipe 8 and the discharge pipe 9. At this time, each annular seal member 20 is compressed and deformed to a state where the backup ring 21 functions. Further, a camp 23 which also serves as a lock nut is screwed into the threaded portion 18 of the free end of the fluid supply pipe 8 and the discharge pipe 9, so that the free end openings of the fluid supply pipe 8 and the discharge pipe 9 are closed.

A portion of both free end corners of each hollow panel 1 is connected to a connecting shaft rod 2 which passes through the seam welded portion 4 of each hollow panel 1 and has a spacer 24 loosely fitted between each hollow panel 1.
5.26, and a nut 27a screwed into the threaded portions at both ends of the shaft rod 25.26.

27b and are similarly fastened and integrated.

Reference numeral 28 denotes a plate for holding the central position of both shaft rods 25 and 26, and is attached to the joint pipe 17 located at the center of the fluid supply pipe 8 and discharge pipe 9 via a bracket 29 and a bolt nut 30. ing.

In the panel heat exchanger configured as above,
The fluid supplied from the main fluid supply pipe 15 enters the fluid supply pipe 8 through the joint pipe 17 and flows out through the slit-shaped flow hole 19. This fluid flows through the reinforcing ring 1 inside each hollow panel 1.
1 flows into one end of the zigzag-shaped flow path 3 in each hollow panel 1 via the radial flow path 13,
It flows through this zigzag-shaped flow path 3 and reaches the other end, and the radial flow path 13 of the reinforcing ring 11 that fits into the fluid discharge pipe 9, the inner circumferential annular groove 12, and the slit-shaped fluid discharge +'1lF9. The fluid flows into the fluid discharge pipe 9 via the circulation hole 19 and is discharged from the fluid discharge pipe 9 via the joint pipe 17 and the main fluid discharge pipe 16.

Therefore, one of the two fluids (the first fluid) which is caused to exchange heat with each other is supplied to the fluid supply main pipe 15, and this panel heat exchanger is installed in the storage tank of the other second fluid or By setting and using the second fluid in the flow path, the second fluid flows in the gap between the hollow panels 1 while the first fluid flows in the flow path 3 of each hollow panel 1. A heat exchange action is performed between the fluid and the fluid, and a desired heat treatment involving heating or cooling is performed.

The panel heat exchanger used as described above can be disassembled and cleaned as follows. That is, the connecting shaft 25.
The nuts 27a and 27b screwed into the free ends of the fluid supply pipes 8 and the discharge pipes 9 are removed, and both shaft rods 25 and 26 are pulled out from each hollow panel 1, and each spacer 24 is removed. By removing the cap 23 and nut 22 that are screwed into the tubes 8.
9 in its axial direction, as a result,
Since each hollow panel 1 can be freely taken out independently, necessary maintenance work can be easily performed.

In addition, as in the above embodiment, the reinforcing ring 1 is attached to the hollow panel 1.
1, the reinforcing ring 11 can be formed wider than the width of the channel 3 of the hollow panel 1, which is convenient for forming the reinforcing ring 11. Not only is it better, but the reinforcing ring 11
There is no need to weld the plate to the plate 2 (therefore, assembly is simplified).

The inner diameter of the reinforcing ring 11 is appropriately larger than the outer diameter of the fluid supply pipe 8 and the discharge pipe 9, so that a sufficiently large annular space is formed between them, and the fluid supply pipe described in +iif is 8 and the discharge pipe 9, when the hollow panel 1 is configured to be positioned by the through holes 10 (see FIG. 6) provided in the plates 2 on both sides of the hollow panel 1, the inner circumferential annular groove 12 can be omitted. Moreover, even if a wide annular space is not formed between the inner circumferential surface of the reinforcing ring 11 and the outer circumferential surfaces of the fluid supply pipe 8 and the discharge pipe 9, the radial flow passage 13 can be configured to be long in the circumferential direction, or , the slit-shaped flow holes 19 provided in the fluid supply pipe 8 and the discharge pipe 9 are configured to be long in the circumferential direction, and the radial flow passages 13 on the reinforcing ring 11 side are provided densely at small intervals in the circumferential direction. etc., the hollow panel 1 is connected to the fluid supply pipe 8
If the radial flow path 13 is configured to always face the slit-shaped flow hole 19 when attached to the discharge pipe 9, the inner circumferential annular groove 12 can be omitted in the same manner as described above.

The reinforcing ring 1+A shown in FIG.
lb are combined in the axial direction so that the troughs 32a and 32b face each other to form a radial flow path 13, and the portions that abut each other are joined together by a joining means such as spot welding. It is configured. According to this reinforcing ring IIA, all parts of the band-shaped body 31 except for the plate thickness part, that is, not only the space between the valleys 32a and 32b but also the outside of the peaks 33a and 33b that contact each other, become the radial flow passage 13. , especially the inner ring as shown in Figure 10.
Although it is not necessary to provide the annular groove 12, the inner annular groove 12 can be formed by cutting out the inner edges of the side wall portions of the valleys 32a, 32b and peaks 33a, 33b, as shown in FIG.

The reinforcing ring IIB shown in FIG.
Two annular bodies 11a and llb comprising 4a and 34b,
The comb tooth-like projections 34a, 34b are adjacent to each other in the circumferential direction, and each projection 34a, 34b is connected to the annular body 11a on the other side.
, llb are stacked in the axial direction so as to be in contact with the side surfaces of the two, and are integrally connected. Such reinforcing ring II
In B, there is a radial flow path 1 between each protrusion 34a, 34b which is spaced apart in the circumferential direction between the re-annular bodies 11a, 1+b.
3 is formed.

The cross-sectional shape of this flow path 13 is such that the comb-like protrusions 34a,
34b, each protrusion 34a, 34b has an arbitrary cross-sectional shape, such as a rectangular shape shown in FIG. 12 or a trapezoidal shape shown in FIG. 13, so that the flow path 13 has a desired cross-sectional shape. It can be configured into any shape. Furthermore, one of the comb-tooth-shaped projections 34a and 34b is configured to be short,
Only the other protrusion may come into contact with the side surface of the annular body 11a or llb on the other side.
4a and 34b can also be spaced apart in the circumferential direction. or,
This reinforcing ring +IB may also have a structure without the inner circumferential annular groove 12 as shown in FIG. An inner circumferential annular groove 12 can also be formed.

The reinforcing ring IIC shown in FIG.
They are integrally connected to each other with 5 interposed therebetween. This spacer 35 is also used as a binding bottle for joining the re-annular bodies 11a and llb, and is caulked with the small diameter shaft portions 35a at both ends passing through the annular bodies 11a and llb. Moreover, welding can also be used, regardless of the caulking method. Of course, a coupling means may be used in addition to the spacer 35.

Such a reinforcing ring 11C is similar to the reinforcing ring 11. described above. Compared to IIA, 11B, the re-annular body 11a, ll can be manufactured at low cost using the flat annular body 112.11b that does not require any special processing.
Since the annular space between b directly becomes the flow passage 13 with a very large flow cross-sectional area, the reinforcing ring is inserted to prevent fluid flow between the inside of the hollow panel 1 and the fluid supply pipe 8 and discharge pipe 9. i,t ii! This can prevent the lti resistance from becoming unduly large. Furthermore, no special processing is required to form the inner circumferential annular groove 12.

As described above, the structure of the reinforcing ring 11 composed of the two annular bodies +1a and 11b is not particularly limited, and of course, the molding material may be various metals, plastics, ceramics, etc., the type of fluid in contact and the usage conditions. In addition, the bank up ring 21 fitted onto the annular sealing material 20 should be selected from all the annular sealing materials 2 when each hollow panel 1 is fastened and integrated.
0 is compressed by a certain amount to equalize the gaps between the hollow panels 1 and to ensure the sealing effect of the annular sealing material 20.
The use of 1 is not a requirement of the invention.

(Effect of the invention) The panel heat exchanger of the present invention that can be implemented as described above has the following features:
It can be easily assembled by simply fitting and fastening each hollow panel to the annular sealing material alternately to the fluid supply pipe and the fluid discharge pipe in the pipe axis direction. Moreover, when each hollow panel is tightened in the axial direction of the fluid supply pipe and the discharge pipe to be integrated, the reinforcing ring prevents the plates on both sides of each hollow panel from bending inward due to the reaction force of the tightening. Since the space between the fluid inlet and the outlet of each hollow panel can be secured to a constant 11, the first fluid can flow into the hollow panel well as expected. Furthermore, due to the presence of the reinforcing ring, a thin plate with the minimum necessary thickness can be used as the plate forming the hollow panel, which can be implemented economically.

Furthermore, since the reinforcing ring forms a radial flow path between the two annular bodies that are connected to each other, even if the flow path has a special cross-sectional shape, it can be integrally formed by cutting the side surface or using a mold. , or zigzag bending of a strip, etc.
It can be constructed by simply joining and integrating two annular bodies, which can be constructed at low cost using a very simple manufacturing method, compared to the case where a large number of through holes are drilled radially in the ring. It can be carried out safely and easily.

In addition, both sides of the reinforcing ring are annular continuous flat surfaces that can be brought into surface contact with the inner surfaces of both side plates of the hollow panel over the entire circumference, so it can be used as a reinforcing ring with radial through holes in one ring. A similar high reinforcement effect can be obtained.

In addition, it can be easily disassembled simply by unfastening each hollow panel and pulling out each hollow panel and annular sealing material from the fluid supply pipe and discharge pipe in the axial direction. If the scale of the two fluids adheres to the surface of each hollow panel, reducing heat exchange efficiency or unduly increasing the flow resistance of the second fluid, disassemble and separate each hollow panel as described above. As a result, necessary maintenance work such as removing scale from the surface of the hollow panel can be performed extremely easily. Therefore, the panel heat exchanger of the present invention can be used without any problem even under conditions where the second fluid is used where scale is likely to form and adhere.

Note that the fluid supply pipe and the fluid discharge pipe are completely isolated from the outside world by each hollow panel and the annular sealing material, which serves as a flow path for the second fluid, and there is no risk of contact with the second fluid. The supply pipe and the fluid discharge pipe need only be made of a material that does not have an adverse effect on the relationship with the first fluid flowing through these pipes, taking into account the conditions of both the second fluid and the second fluid. There is no need to select the material. For example, if the first fluid is water, hot water, water, etc., the fluid supply pipe and fluid discharge pipe are inexpensive even if the second fluid is strongly acidic. It is economical because it can be made of iron-based materials (SS, SUS, etc.).

[Brief explanation of the drawing]

Fig. 1 is a partially longitudinal front view, Fig. 2 is a partially longitudinal front view, Fig. 3 is an enlarged sectional view taken along line A-A in Fig. 1, and Fig. 4 is a partially longitudinal sectional front view.
[An enlarged sectional view taken along line B-B of m, Figure 5 is C- of Figure 4.
FIG. 6 is an enlarged vertical sectional side view of the main part of the present invention, FIG. 7 is a partially vertical front view of the reinforcing ring, and FIG. 8 is an enlarged plan view of the main part of the reinforcing ring. , Figures 9 and 1
Figure 2 is a plan view of the main parts showing another embodiment of the reinforcing ring;
Fig. 10 is a longitudinal sectional view of Fig. 9, Fig. 11 is a longitudinal sectional view of main parts showing a modification of the reinforcing ring shown in Fig. 9, and Fig. 13 is a modification of the reinforcing ring shown in Fig. 12. A plan view of the main part showing an example, Fig. 14 is a longitudinal sectional view of Fig. 12, and Fig. 15 is a plan view of the main part.
2 is a vertical sectional view showing a modification of the reinforcing ring shown in FIG.
Figure 6 is a perspective view showing another embodiment of the reinforcing ring, Figure 17.
The figure is a longitudinal cross-sectional view. DESCRIPTION OF SYMBOLS 1... Hollow panel for heat exchange, 7... Hollow panel wide part, 8... Fluid supply pipe, 9... Fluid discharge pipe, 10...
...Through hole, l+lIA~1+C...Reinforcement ring,
11a, 11b... Annular body, +1c... Binding bottle,
12... Inner circumferential annular groove, 13... Radial flow passage, 15...
...Fluid supply main pipe, 16...Fluid iJ) birth pipe, 19
... S'J Nol-shaped circulation hole, 20 ... Annular sealing material, 21 ... Back anopuring, 22.27a, 27
b-- Nut, 23... Cap for lock nut i, 24... Spacer, 25.26... Connecting rod, 28... Axial rod support plate, 31... Band-shaped body,
34a, 34b... comb teeth, 35... spacer.

Claims (8)

[Claims] (1) A heat exchange hollow panel formed by joining two plates to each other so as to form a flow path between the two plates is provided with through holes through which a fluid supply pipe and a fluid discharge pipe are passed separately,
A reinforcing ring is interposed between the both side plates around the through hole to prevent the gap between the both side plates from narrowing and has a radial flow path, and a fluid supply having a flow hole on the outer periphery. The required number of hollow panels are fitted to the pipe and fluid discharge pipe so that they can be pulled out in the pipe axis direction and disassembled, with annular sealing material externally fitted to the fluid supply pipe and discharge pipe between each hollow panel. and a panel-type heat exchanger in which the two annular bodies are fastened together, and the reinforcing ring has two annular bodies,
A panel heat exchanger characterized in that both annular bodies are integrally connected in the axial direction so as to form the radial flow passages. (2) The heat exchanger according to item (1), wherein the through-hole forming portion of the hollow panel is formed by bulging both side plates outward to form a wide portion, and the reinforcing ring is fitted into the wide portion. (3) The heat exchanger according to item (1) or item (2), wherein the reinforcing ring includes an inner circumferential annular groove formed between both annular bodies and communicating with the radial flow path. vessel. (4) Each of the annular sealing materials is fitted with a backup ring that prevents the gap between adjacent hollow panels from becoming less than a certain level. Heat exchanger described in. (5) The reinforcing ring connects and integrates two annular bodies having radial recesses on opposing side surfaces in alignment in the axial direction so that the recesses face each other to form a radial flow path. The heat exchanger according to any one of the above items (1) to (4). (6) The reinforcing ring aligns two annular bodies formed by bending a band-shaped body in a zigzag shape in the circumferential direction in the axial direction so that the valleys face each other to form a radial flow path. Items 1 to (4) above, which are configured in a combined and integrated manner.
) The heat exchanger described in any of the above. (7) The reinforcing ring connects two annular bodies each having comb-tooth-like protrusions protruding toward opposing side surfaces at appropriate intervals in the circumferential direction, and the comb-teeth-like protrusions are adjacent to each other in the circumferential direction, and The method according to any one of the above items (1) to (4), wherein the protrusion of at least one annular body is stacked in the axial direction so as to be in contact with the side surface of the other annular body and are integrally connected. Heat exchanger. (8) Items (1) to (1) above, wherein the reinforcing ring is constituted by integrating two flat annular bodies with spacers interposed at appropriate intervals in the circumferential direction, with the reinforcing ring being separated at appropriate intervals. 4) The heat exchanger according to any one of paragraphs.