JPS58174711A - Mounting structure of composite tube and tube plate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a mounting structure for mounting an end portion of a composite pipe to a tube sheet by welding.

[Technical background of the invention]

BACKGROUND ART Composite tubes made of a combination of different metals are sometimes used as heat transfer tubes for heat exchange equipment in geothermal power generation and the like. Figure 1 shows an example. This composite tube 1 has an intermediate layer 2 made of a copper alloy plate with good thermal conductivity, an outer surface layer 3 made of stainless steel plate or titanium with good corrosion resistance, and an inner layer 3 made of stainless steel plate or titanium with good corrosion resistance on the outer and inner circumference sides. The surface layer 4 is overlapped, and both side edges of each of these layers 3 to 4 are joined by welding in the longitudinal direction to form a pipe body,
A groove portion 5 is formed in each surface layer II4. This composite pipe 1 has the advantage of being able to economically achieve both heat conductivity and corrosion resistance by combining the layers 2 to 4 of each metal.

However, when the lever composite tube 1 is attached to and supported by a tube sheet in heat exchange equipment, holes r are formed in a tube sheet 6 made of stainless steel plate or chi/y&, as shown in FIG.
The end of the composite pipe 1 is fitted to the end of the composite pipe 1, and the space between the end of the composite pipe 1 and the tube sheet 2 is pushed apart along the circumferential direction of the composite pipe 1 to fix it, and then the joint is welded by welding or IIG welding. It is fixed by applying.

[Problems with background technology]

Generally, the tube sheet 6 is required to have corrosion resistance like the heat exchanger tube, so it is made of the same stainless steel plate or titanium as the surface layer 3.4 of the composite tube 10. Further, the ends of the composite pipe 1 are usually arranged so that the ends of the layers 2 to 4 are aligned at the same position. When welding is performed across the composite pipe 1 and tube plate 6 in this state, the welded portion 8
An alloy layer is formed by adding the copper alloy of the intermediate layer 2 to the surface layers 3 and 4 of the composite tube 1 and the stainless steel or titanium of the tube sheet 6.

For this reason, the mechanical strength of the welded portion 8 is reduced due to the formation of an alloy layer, and the fixation of the composite pipe 1 and the tube sheet C becomes uneasy. In addition, the alloy layer causes bubbles inside the welded portion, which may reduce weldability and cause fluid to leak from the inside of the tube sheet 6 to the outside.

[Purpose of the invention]

The present invention fixes a composite tube having a metal layer made of the same material as the tube sheet by welding it to the tube sheet, and improves the mechanical strength and airtightness of the welded part, and improves the bond between the composite tube and the tube sheet. This provides a mounting structure between a composite pipe and a tube sheet that allows for good installation of the pipe.

[Summary of the invention]

The mounting structure of the composite pipe and tube sheet of the present invention is such that the welded portion is welded to the tube sheet by welding the metal layer of the composite pipe made of the same material as the tube sheet except for the metal layer made of a different material from the tube sheet. It is made of one type of metal that forms the plate, and prevents the formation of an alloy layer at the welded part.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIG.

In this embodiment, a composite tube 1 shown in FIG. 1 is used, in which an intermediate layer 2 made of a copper alloy is combined with an outer surface layer J and an inner surface layer 4 made of titanium. Also, composite pipe 1
At the end of the intermediate layer 2, the end of the intermediate layer 2 is in a shorter position (than the end of the outer layer 3.4), and the outer and inner outer layers 3, 4 extend outward from the end of the intermediate layer 2 and are pressed against each other. are doing. For this reason, the end of the composite tube 1 is such that the end of the intermediate layer 2 is the same as that of the image surface layer 3.
It is located on the inner side from the end of the surface layer 3 and 4 and is not exposed because it is covered by the end of the surface layers 3 and 4, and only the end of the surface layer 3.4 extends to the outside. This composite tube 1 is made by forming a copper alloy plate forming the intermediate layer 2 and a titanium plate tube forming the outer and inner surface layers 3 and 4 into a tubular shape, and welding the edges on both sides of each gold maple plate. It is manufactured by joining, and in order to achieve the above-mentioned end configuration, a short copper alloy plate is used during manufacturing, or the end of the copper alloy plate is cut by fusing or cutting. , the edges of the titanium plate are pressed together. Furthermore, the tube plate 6 is made of titanium,
A hole 7 is formed.

The ends of the composite tube 1 are fitted into the holes 7 of the tube plate 6 at the ends of the outer surface layer 3 and the inner surface layer 4 extending from each other. TIG welding is performed along the circumferential direction of the composite tube 1 and the hole 7 between the ends of the outer surface layer 3 and the inner surface layer 4 fitted into the hole 1 of the tube sheet 6 and the tube sheet 6. A portion 8 is formed. The outer and inner surface layers 3, 4 and the tube sheet 6 are fixed by this welded portion 8.

Here, at the end of the composite pipe 1, the intermediate layer 2 is covered by the outer and inner surface layers 3 and 4 and is not located at the welded part with the tube sheet 6, so the intermediate layer 2 made of a metal different from that of the tube sheet 6
Welding is carried out between the tubesheet 6 and the outer and inner surface layers 3.4, which are made of the same metal as the tubesheet 6, with the exception of . Therefore, the welding part 8 that fixes the composite pipe 1 and the tube sheet 6 is
and the same kind of metal forming the tube sheet 6, in this embodiment only titanium, and no alloy layer of titanium and a different metal, that is, a copper alloy forming the intermediate layer 2, is formed. Therefore, since no alloy layer is formed in the welded portion 8, the mechanical strength is excellent, and the welded portion 8 has excellent airtightness because no air bubbles are formed. As a result, the composite pipe 1 and the tube plate d are connected to the welded part 8.
It is possible to securely fix the tube plate 6 and the composite tube 1, and to maintain airtightness at the welded portion between the tube sheet 6 and the composite tube 1.

4 and 5 show other embodiments of the invention. This embodiment deals with a composite pipe 1' having two layers as shown in FIG. 4: an outer layer 9 made of, for example, a copper alloy and having a groove 5 formed therein, and an inner layer 10 made of, for example, stainless steel or titanium. It is made by superimposing them to form a tube. At the end of this composite tube 1', the end of the outer layer 9 is located inside the end of the inner layer 10, and the end of the inner layer 10 extends outward from the end of the outer layer 9. The composite pipe 1' is manufactured by superimposing a steel alloy plate forming the outer layer 9 and a stainless steel plate or titanium forming the inner layer 10 to form a tubular shape, and joining both side edges of each metal plate by welding. However, during manufacturing, a copper alloy plate having a shorter length than the stainless steel plate is used, or the edge of the steel alloy plate is cut by melt cutting or cutting to achieve the above-mentioned end configuration. Then, as shown in Fig. 5, the composite pipe 1
The end of the inner layer 10 at the end of the tube sheet 6 is fitted into the hole 1 of the tube sheet 6, and the composite tube 1' is inserted between the end of the inner layer 10 and the tube sheet 6.
A welded portion 8 is formed by performing TIG welding or the like along the circumferential direction. For this reason, the composite tube 1' is fixed to the tube plate 6 by the welded portion 8. Here, welding between the composite pipe 1' and the tube sheet 6 is performed by welding the inner layer 1o made of the same metal as the tube sheet d and the tube sheet 6, except for the outer layer 9 made of a metal different from the tube sheet 6. A welded portion 8 made of similar metals, ie, stainless steel or titanium, is formed, and no alloy layer of stainless steel or titanium and a dissimilar metal, ie, copper alloy, is formed in the welded portion 8.

Therefore, the composite pipe 1' and the tube plate 6 are firmly fixed to the welded portion 8), and the cylindrical nature of the welded portion 8 can be improved.

Note that the configuration of the end portion of the composite tube is not limited to the above-described embodiment, and may be any structure in which only a metal layer made of the same type of metal as the tube sheet is welded to the tube sheet.

〔Effect of the invention〕

The mounting structure of the composite pipe and tube sheet of the present invention is to weld the tube sheet to a metal layer made of the same material as the tube sheet, except for the metal layer of the composite pipe made of a different material from the tube sheet. 1'r
To improve the mechanical strength and cylindrical nature of the welded part by forming the same kind of metal together, thereby securely fixing the composite pipe and the tube sheet, and also keeping the atmosphere at the fixed part in a good condition. I can do it.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing an example of a composite pipe, Figure 2 is a longitudinal cross-sectional view showing a conventional mounting structure between a composite pipe and a tube plate, and Figure 3 is a cross-sectional view showing an example of a composite pipe.
The figure is a longitudinal cross-sectional view showing one embodiment of the mounting structure of the present invention.
The figure is a cross-sectional view showing another example of a composite pipe, and FIG. 5 is a vertical cross-sectional view showing another example of the mounting structure of the present invention. 1.1'... Composite pipe, 2... Intermediate layer, 3, 4...
Surface layer, 6... Tube sheet, 7... Hole, 1... Welded part, 9
...outer layer, noO...inner layer. Applicant's agent Patent attorney Takehiko Suzue 2 Figure 1 Figure 2

Claims (1)

[Claims] An end portion of a composite pipe formed by combining at least two metal layers made of different materials is fitted into a hole formed in a tube sheet, and the metal layer of the composite pipe is made of a material different from that of the tube sheet. A mounting structure of a composite pipe and a tube sheet, which is formed by welding the end of a metal layer made of the same material as the tube sheet and the tube sheet, except for the above.