JPH0985466A - Structure of joining part of double pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely center and join double pipes in a short time. SOLUTION: In a case of joining mutual double pipes 31, 32, because the communicating state of the clearance 30 at the joining part 34 has to be kept surely, so the high precision is required in centering of the joining part 34. In this time, a conical recessing face 34a is formed on the joining part 34 of one side double pipe 31, a conical projecting face 34b is formed on the joining part 34 of the other side double pipe 32, and centering of both can be executed exactly in a short time by only butting the double pipes 31, 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double pipe joint structure.

[0002]

2. Description of the Related Art For example, in recent years, a heat exchanger 1 having a conceptual view shown in FIG. 6 has been manufactured.

In the heat exchanger 1, the upper end of a tubular heat exchanger body 2 is partitioned by a tube plate 3a to form a first chamber 4a, and the tube plate 3b is partitioned to form a second chamber 4b. In addition,
A third chamber 4c is formed by partitioning with a tube plate 3c, and similarly, a lower end of the heat exchanger body 2 is partitioned with a tube plate 3d to form a fourth chamber 4d.
And a fifth chamber 4e is formed by partitioning with the tube plate 3e, and a sixth chamber 4f is formed by partitioning with the tube plate 3f, and the first chamber 4a and the fourth chamber 4d are While communicating with the pipe 5, the second chamber 4b and the fifth chamber 4e are communicated with the outer pipe 6,
Furthermore, the third chamber 4c and the sixth chamber 4f are connected by the heat transfer tube 7.

Then, the primary fluid 8b generated by the heat generation source 8a such as a furnace is supplied to the first chamber 4a by using the pump 8c to pass the inside of the inner pipe 5, and then the fourth chamber. 4d, while supplying the secondary fluid 9d using the pump 9c to the supply port 9b on the upper end side of the heat exchange chamber 9a formed in the middle of the tube plates 3c and 3f, the secondary fluid 9d is heated. After passing through the exchange chamber 9a, a discharge port 9e on the lower end side of the heat exchange chamber 9a
Is discharged from the primary fluid 8b and the secondary fluid 9
Heat is exchanged with d. Then, the tertiary fluid 10a such as seawater is supplied to the sixth chamber 4f by using the pump 10b to pass through the inside of the heat transfer tube 7, and then is discharged from the third chamber 4c, whereby the secondary fluid 9d is discharged. And tertiary fluid 10a
Exchange heat with.

Further, the detection gas 11b is supplied to the second chamber 4b using the pump 11a, and the detection gas 11b is passed through the gap 12 between the inner pipe 5 and the outer pipe 6, and then the fifth gas is supplied. Room 4e
It is possible to detect damage to the inner pipe 5 or the outer pipe 6 by discharging the gas from the inner pipe 5 and circulating it, causing the leak detector 11c to detect the leak of the detection gas 11b, and issuing an alarm from the alarm device 11d. There is.

As shown in FIG. 7, the inner tube 5 and the outer tube 6 are integrated as a whole by interposing a mesh wire layer 21 having a thickness of about 0.4 mm formed by braiding a wire in the gap 12. It is configured as a double tube 22 having a mesh structure, and the layer 21 of mesh wires ensures the gas permeability of the detection gas 11b.

Since the double pipe 22 is difficult to manufacture, only a length of 7 to 8 m is currently manufactured, but the steam generator 1 requires a length of several tens of m. Therefore, it is necessary to join a plurality of double pipes 22 to have a desired length.

When the double pipes 22 are joined together, as shown in FIG. 8, first, the inner pipes 5 are butted and welded (welded portion 23), and then the outer pipes 6 are butted and welded. (Welding portion 24) is conceivable. However, in this case, it is difficult to secure the gap 12 between the inner pipe 5 and the outer pipe 6 at the joint portion, and thus, conventionally, as shown in FIG. The inner pipes 5 are butted to each other and welded (weld portion 23), and then the joint pipe 25 is provided between the outer pipes 6 formed to be shorter than the inner pipe 5.
Was fitted on the outside of the joint pipe 25 and fillet welded between the both ends of the joint pipe 25 and the corresponding outer pipe 6 (welded portions 26).

[0009]

However, the above-mentioned conventional means for joining the double pipes has the following problems.

That is, as shown in FIG. 9, the inner pipes 5 are butted and welded (welded portion 23), and then the joint pipe 25 is externally fitted between the outer pipes 6 formed to be shorter than the inner pipe 5. Then, when the fillet welds are made between the both ends of the joint pipe 25 and the corresponding outer pipe 6 (welding portions 26), welding is required three times and the diameter of the joint pipe 25 is increased. The size becomes large.

However, since the double tubes 22 are densely arranged in the heat exchanger 1 on the order of hundreds to several hundreds,
There is a problem that the presence of the large-diameter joint pipe 25 makes it difficult to handle the double pipe 22, and the presence of the joint pipes 25 having different diameters also lowers the heat exchange efficiency.

In view of the above-mentioned circumstances, the present invention has an object to enable the double pipes to be joined together without forming a large diameter portion.

[0013]

SUMMARY OF THE INVENTION According to the present invention, a convex surface is formed on one of the joints of double pipes which are integrated by interposing a layer of wire in the gap between the inner pipe and the outer pipe, and the other is formed. The present invention relates to a joint structure of a double pipe, characterized in that a concave surface that matches the convex surface is formed. In this case, the convex surface may be a conical convex surface and the concave surface may be a conical concave surface.

When joining the double pipes together, it is necessary to secure the communication state of the gaps at the joints, and therefore high precision is required for centering the joints. By forming a concave surface on the joint part and forming a convex surface on the joint part of the other double pipe, it is possible to accurately perform centering of both by simply abutting the double pipes. Become.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 4 show a first embodiment of the present invention.

The double pipes 31, 32 are joined together by interposing a layer 27 of a wire having a thickness of about 0.4 mm formed by braiding a wire in a gap 30 between an inner pipe 28 and an outer pipe 29. In this case, the conical concave surface (concave surface) 34a is formed in the joint portion 34 of the one double tube 31 and the other double tube 3 is formed.
A conical convex surface (convex surface) 34b that coincides with the conical concave surface 34a is formed on the joint portion 34 in FIG.

In the figure, 33 is an insert such as an amorphous material such as iron-based, nickel-based, copper-based, titanium-based, etc. having a thickness of 25 to 60 μm, which is interposed in a joint portion 34 between the double tubes 31, 32. It is a material, and is processed into a tapering shape in accordance with the conical concave surface 34a and the conical convex surface 34b.

Reference numeral 35 is a pressurizing device capable of gripping the double pipes 31, 32 in a butted state and applying a pressing force between the double pipes 31, 32.

The pressurizing device 35 is provided with an outer cylinder 38 having a U-shaped clamp portion 37 having a set screw 36 on its side.
An inner cylinder 40 having a similar clamp portion 39 is slidably fitted, and an elastic body 41 such as a coil spring capable of urging in a separating direction is interposed between the inner cylinder 40 and the inner cylinder 40. A cylinder attachment portion 44 having a hook-shaped portion 43 to which the pressure cylinder 42 can be attached is provided at the end of the.

Reference numeral 45 is an elongated hole formed in the outer cylinder 38 for guiding the movement of the clamp portion 39, 46 is a hydraulic device of the pressurizing cylinder 42, and 47 is a key provided in the pressurizing cylinder 42. An engagement protrusion that engages with the cylindrical portion 43, 48 is a piston of the pressurizing cylinder 42, and 49 is a piston hole through which the piston 48 formed in the cylinder mounting portion 44 passes.

Numerals 50 and 51 are a pair of direct current-carrying electrodes which have a two-part structure and can be attached to the double tubes 31 and 32, and are capable of supplying and discharging water 52 to cool the inside. There is. Incidentally, 53 is a mounting bolt for mounting the respective direct energizing electrodes 50, 51 to the double pipes 31, 32, 54 is a direct energizing power source connected to each direct energizing electrode 50, 51, and the hydraulic device The signal 55 can be exchanged with 46.

Reference numeral 56 is a joint portion 3 between the double pipes 31 and 32.
4 is a shield gas chamber that can be attached to the No. 4, and the shield gas chamber 56 has a split structure (not shown), and has a heat-resistant insulating member 57 in a portion in contact with the outer peripheral surfaces of the double pipes 31 and 32. A shield gas supply source 58 such as an inert gas cylinder containing a shield gas such as an inert gas is connected via a valve 59.

Next, the operation will be described.

A double layer 31, 32 made of braided wire and having a thickness of about 0.4 mm and a mesh wire layer 27 interposing in a gap 30 between an inner tube 28 and an outer tube 29 is abutted to each other. In the case of joining, first, a conical concave surface 34a is formed in the joining portion 34 of the double pipe 31 by using a lathe, and the double pipe 3
The conical convex surface 34b is processed and formed on the second joint portion 34.

Next, the double pipe 31, with the insert material 33 made of a sheet-like amorphous material having a thickness of 25 to 60 μm, such as iron-based, nickel-based, copper-based or titanium-based material, interposed.
32 match each other.

When the double pipes 31 and 32 are abutted with each other in this way, it is necessary to secure the communication state of the gap 30 portion in the joint portion 34, and therefore high accuracy is required for centering the joint portion 34. However, a conical concave surface 34a is formed in the joint portion 34 of one double pipe 31 and the other double pipe 32 is formed.
Since the conical convex surface 34b is formed in the joint portion 34, the centering of the double pipes 31 and 32 can be accurately performed in a short time by merely abutting the double pipes 31 and 32.

In this state, the U-shaped clamp portion 37 on the outer cylinder 38 side of the pressurizing device 35 is connected to the double pipe 3 on one side.
1 is externally fitted and fixed with a set screw 36, and similarly, the clamp portion 39 on the inner cylinder 40 side is externally fitted to the other double pipe 32 and fixed with the set screw 36.

Furthermore, in the pressurizing device 35, the engaging protrusion 47 is engaged with the key-like portion 43 of the cylinder mounting portion 44 provided at the end of the outer cylinder 38 on the side of the anti-elastic body 41, and the pressurizing cylinder 42 is engaged. And the hydraulic device 46 is connected to the pressurizing cylinder 42.

A direct current-carrying electrode 50 having a split structure is attached near the joint 34 of the double pipe 31 and is fixed by a mounting bolt 53, and a direct current having a split structure is provided near the joint 34 of the double pipe 32. The electrode 51 is attached and fixed with a mounting bolt 53, and the direct energizing power source 54 is connected to each of the direct energizing electrodes 50 and 51, and a signal 55 is exchanged between the direct energizing power source 54 and the hydraulic device 46. Connect the signal lines as you can.

Further, the joint 3 between the double pipes 31 and 32
A shield gas chamber 56 having a two-part structure is attached to 4, and a shield gas supply source 58 such as an inert gas cylinder containing a shield gas such as an inert gas is connected to the shield gas chamber 56 via a valve 59.

When the above preparation is completed, the valve 59 is opened to inject a shield gas such as an inert gas from the shield gas supply source 58 into the shield gas chamber 56, and the water 52 is directly supplied to the energizing electrodes 50 and 51. While discharging and cooling the inside, the electrodes 50, 51 for direct conduction are directly supplied from the power supply 54 for direct conduction.
A high-voltage current is applied to.

Then, the current is applied directly to the electrodes 50, 5 for energization.
It flows through the joint portion 34 of the double pipes 31 and 32 which is the shortest distance between the two, and the joint portion 34 having the largest electric resistance among these flows.
Cause resistance heating. At the same time, a direct power supply 54
From the hydraulic device 46 to the hydraulic device 46 via a signal line,
The piston 48 of the pressurizing cylinder 42 is extended, the inner cylinder 40 is biased in the proximity direction against the elastic body 41, and the double tubes 31, 32 are pressed against each other. The pressurizing device 35
There is no worry about electric leakage from.

As a result, as shown in FIG. 3, the amorphous insert material 33 interposed in the joint portion 34 is melted, and the melted amorphous insert material 33 is liquid phase diffused to the end faces of the double pipes 31, 32. As a result, as shown in FIG. 4, the boundary between the joints 34 between the double pipes 31 and 32 disappears, and a tissue almost equal to that of the other portions is formed, and the double pipes 31 and 32 are integrally and firmly formed. To be joined.

The current value to be applied may be a value that reaches the melting temperature of the insert material 33, and the energization time is about 1
It is about 0 to 30 seconds.

At this time, the amorphous insert material 3
Since 3 is an extremely thin layer having a thickness of 25 to 60 μmm, the gap 30 between the double tubes 31 and 32 is not collapsed and the gap 30 is left as it is.

Further, the joint portion 34 is connected to the shield gas chamber 5
Surrounding with 6 is to inject and supply the shield gas at the joint 3
This is to prevent 4 from being oxidized.

As described above, by directly energizing the double tubes 31, 32, it is possible to stably and automatically perform highly efficient joining in a short time.

Further, since spatter and burrs are not generated at all, post-processing of joining can be unnecessary.

Further, in the case of direct energization, it is not necessary to dispose the direct energizing power source 54 and the like, which has the largest configuration, in the vicinity of the joint portion 34, and it is possible to place the direct energization power source considerably away from the joint portion 34. The working environment can be improved.

Moreover, the conical concave surface 34a is formed in the joint portion 34 of the one double pipe 31, and the joint portion 3 of the other double pipe 32 is formed.
By forming the conical convex surface 34b on the double pipe 4,
Only by butting together 1, 32, the centering of the both can be performed accurately in a short time. Therefore, for the purpose of centering, the pressurizing device 35 can be manufactured with high accuracy or the pressurizing device 35 can be operated with high accuracy. Double tube 3
It is possible to eliminate the need to set 1, 32.

FIG. 5 shows a second embodiment of the present invention, which is a direct current source 54 and direct current electrodes 50, 51.
Instead of using, the gas heating device 61 having a ring-shaped nozzle portion 60 capable of externally surrounding the joint portion 34 is used.

Reference numeral 62 denotes an oxygen supply source connected to the gas heating device 61 via an oxygen hose 63, and 64 a fuel supply for storing fuel such as acetylene connected to the gas heating device 61 via a fuel hose 65. Is the source.

In the present embodiment, the ring-shaped nozzle portion 60 of the gas heating device 61 is fitted around the joint portion 34 of the double pipes 31 and 32, and in this state, the fuel supply source 64 is connected to acetylene or the like. The fuel is supplied through the fuel hose 65, and the oxygen supply source 62 supplies oxygen through the oxygen hose 63 in an amount smaller than that required for complete combustion of the fuel to generate a reducing flame. While preventing oxidation of the joint portion 34, the insert material 33 of the joint portion 34 is heated and melted, and the double pipes 31 and 32 are joined by liquid phase diffusion of the melted insert material 33.

Even in this case, the double pipes 31 and 32 can be easily joined together as in the above-described embodiment.

Although not shown in the drawing, a conical concave surface 34a is formed on the joint portion 34 of one double pipe 31 and a conical convex surface 34b is formed on the joint portion 34 of the other double pipe 32.
By simply butting the double pipes 31 and 32, the centering of the two pipes can be accurately performed in a short time. Therefore, for the centering, the pressurizing device 35 can be manufactured with high precision, or the pressurizing device 35 can be manufactured. 35
The point that it is possible to eliminate the need to set the double tubes 31 and 32 with high accuracy is the same as in the above-described embodiment.

Except for the above, the structure is the same as that of the above-mentioned embodiment, and the same operation and effect can be obtained.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0049]

As described above, according to the joint portion structure of the double pipe of the present invention, the excellent effect that the double pipe can be surely aligned and joined in a short time can be obtained. .

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a first embodiment of the present invention.

FIG. 2 is a schematic side view of FIG.

FIG. 3 is a side cross-sectional view showing a joint between the double pipes before joining.

FIG. 4 is a side sectional view showing a state after joining in FIG.

FIG. 5 is a schematic side view of a second embodiment of the present invention.

FIG. 6 is a side sectional view showing the concept of a steam generator.

7 is a cutaway perspective view of a double tube used in the steam generator of FIG.

FIG. 8 is a side cross-sectional view showing a commonly-considered double-tube joining configuration.

FIG. 9 is a side sectional view of a conventional example.

[Explanation of symbols]

 28 Inner pipe 29 Outer pipe 27 Layer of mesh wire 31, 32 Double pipe 34 Butt portion 34a Concave surface (conical concave surface) 34b Convex surface (conical convex surface)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B23K 33/00 B23K 33/00 A F28F 1/00 F28F 1/00 C

Claims (2)

[Claims] 1. A convex surface is formed on one of the joints of double pipes which are integrated by interposing a layer of mesh wire in the gap between the inner tube and the outer tube, and a concave surface matching the convex surface is formed on the other side. A double-tube joint structure characterized by being formed. 2. The double pipe joint structure according to claim 1, wherein the convex surface is a conical convex surface and the concave surface is a conical concave surface.