JPH0322637Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a connection structure for heat-insulating pipes. Specifically, another inner pipe is coaxially arranged on the inner surface of a metal pipe, and this inner pipe and a metal This invention relates to a connection structure for heat-insulating pipes, which is formed by sealing a heat-insulating material in the space between the inner surface of the pipe and the inner surface of the pipe.

[Prior Art] Conventionally, as shown in FIG. 7, another inner tube B is disposed coaxially on the inner surface of a metal tube A as an insulated tube.
A particulate heat insulating material C having a porous structure, for example, an inorganic heat insulating material such as diatomaceous earth or perlite, is filled between the inner tube B and the inner surface of the metal tube A. Insulated tubes are known that are closed and sealed with a metal plate E and, in some cases, have a filling space D evacuated (for example, Japanese Patent Application Laid-Open No. 1983-1999)
Publication No. 155996).

This type of heat-insulated pipe has the advantage that thermal bridges in the double-walled pipe wall space are extremely small, and in combination with the heat insulating material filled inside, it exhibits a very good heat-insulating effect.

[Conventional Problems] However, the above-mentioned insulated pipes have a rigid structure and a thick peripheral wall, making it difficult to connect the pipes, and even if they can be connected, heat tends to escape from the connection area. However, there was a problem in that as the number of connection points increased, the insulation effect of the entire pipeline decreased accordingly.

For example, in order to connect with a socket socket as in conventional ordinary pipes, it is extremely difficult to mold the socket, and the wall thickness of the pipe line becomes substantially thicker due to the insulation layer. Therefore, there is a problem that the volume of the pipe connection part becomes large, making it impossible to make it compact.In addition, heat easily escapes through the metal pipe that forms the outer periphery of the socket inserted into the socket, and heat loss cannot be ignored. There is a problem.

For this reason, this type of heat-insulated pipes are mainly connected by welding the outer peripheries of the ends of abutted metal pipes together as shown in the figure.

However, even with such welding, the inner pipe B
and metal plates E, E that seal the end face between the metal tube A and the metal tube A.
Since there is no welding between the metal plates E and E, this part is not insulated.To solve this problem, we also weld the metal plates E and E as shown by the chain line, and the heat of the fluid flowing inside the pipe is This caused a problem in that the inner tube B was thermally expanded and contracted in the axial direction, causing cracks due to the enormous stress, and the watertightness of the space D filled with the heat insulating material was impaired.

As seen in Japanese Patent Laid-Open No. 55-123090, a connection structure for heat-insulating pipes that solves these problems is such that the end surface of the pipe is made into a bellows-like end surface to prevent expansion and contraction movement in the radial direction of the inner tube and in the axial direction of the tube end surface. A structure has been proposed that allows this, but with this structure, the combination of connection directions of the tubes is determined by the bellows-like bending state of the tube end surface, and in the case of long tubes, it is difficult to connect. There is a drawback that the construction is extremely troublesome, and furthermore, the structure of the bellows-like tube end portion is complicated, making it troublesome to mold and assemble, making it difficult to implement.

[Problems to be solved by the invention] In view of the above-mentioned problems, this invention allows for easy connection of insulated pipes, good heat insulation at the connection part, and even if the inner pipe expands and contracts due to heat. This was done with the aim of providing a connection structure for heat insulating pipes that can sufficiently absorb this.

[Technology that solved the problem] In the connection structure of the heat-insulated pipe of this invention, another inner pipe is coaxially arranged on the inner surface of the metal pipe, and the space between the inner pipe and the inner surface of the metal pipe is A space in which insulating tubes filled with a heat insulating material and whose axial end faces are closed and sealed by recessed metal plates are connected and arranged on the same axis and surrounded by the recessed end faces of the abutted abutted heat insulating pipes. This is characterized in that a tube body whose side surface is open inward is inserted into the tube, and the metal tubes are connected to each other.

[Example] Next, this invention will be explained using examples.

FIG. 1 is a sectional view of a main part of an embodiment of this invention.

In the connection structure of the heat-insulating pipe of this invention, another inner pipe B is arranged as a membrane on the inner surface of the metal pipe A, and the space between this inner pipe B and the metal pipe A is filled with inorganic material such as diatomaceous earth or perlite. The end face of the filling space D filled with foamed heat insulating material C in the tube axis direction is closed and sealed by a recessed metal plate 1, and depending on the case, the filling space D
Insulated tubes 2 made of vacuum are connected and arranged on the same axis, and the side surface 3A is inward of the tubes (in the direction of arrow P) along the inner surface of the space surrounded by the recessed end surfaces 1' of the abutted insulated tubes 2, 2. A tube body 4 opened to the metal pipes A is inserted, and the metal pipes A and A are connected to each other.

In the above embodiment, the metal tubes A and A are connected by welding F, and in this case, the tube body 4
To prevent the effects of heat, as shown,
A heat insulating material 5 is inserted between the tube body 4 and the welding location.

Incidentally, when the metal pipes A are connected by, for example, a threaded joint 6 as shown in FIG. 2, the above-mentioned heat insulating material is not required.

Furthermore, in the above embodiment, the side surface of the tube body 4 was opened by incision, but as shown in FIGS.
As shown in the figure, a hole 7 may be provided on the side surface. The embodiments shown in FIGS. 3 and 4 are the same as the embodiments shown in FIGS. 1 and 2 except for the hole structure of the tube body 4, so the same reference numerals are used in the figures. Detailed explanation will be omitted.

[Function] In the connection structure of the heat insulation pipes in this invention, the recessed end surfaces 1' on the inner surfaces of the pipe ends of the heat insulation pipes 2, 2 to be connected are covered with, for example, a rubber tube, so that the tube body 4 improves the heat insulation. In addition, the internal hot water flows into the space inside the tube body 4 and accumulates therein, so that the internal fluid itself also exhibits a heat insulating effect.

In addition, even if the inner tube B expands and contracts in the axial direction due to the heat of the internal fluid, as shown in FIGS. 5 and 6, while maintaining mutual insulation and water tightness,
The inner tube B is movable in the axial direction relative to the metal tube A, and together with the fact that the tube body 4 has open sides, thermal expansion and contraction can be carried out easily.

At this time, the inner tube B also expands and contracts in the radial direction, but the movement in this direction is also caused by the recessed metal plates 1,
It is allowed by an easy bendability of 1.

[Effect] Since this device is constructed as described above, even though welding and joints are used, the tube body 4 provides sufficient heat insulation to the welded portion, and distortion caused by heat is prevented. However, due to the shape of the tube end surface, even if it is absorbed in either the axial or radial direction, the inner surface of the connection part of the metal tube A is completely sealed by the tube body 4, so that, for example, internal fluid can be absorbed easily. It has the practical effect of being sufficiently protected from liquids that corrode metals, such as hot spring water and chemicals, and providing reliable heat insulation function over a long period of time.

[Brief explanation of drawings]

Fig. 1 is a sectional view of one embodiment of this invention, Figs. 2 to 4 are sectional views of other embodiments, Figs. 5 and 6 are sectional views of still other embodiments, and Fig. 7. is an explanatory sectional view of a conventional example.

Claims (1)

[Claims for Utility Model Registration] (1) Another inner tube is disposed coaxially with the inner surface of the metal tube, and the space between the inner tube and the inner surface of the metal tube is filled with a heat insulating material to fill the filled space. Insulating tubes whose end surfaces in the tube axis direction are closed and sealed by recessed metal plates are connected and arranged on the same axis, and the side surfaces are opened inward into the space surrounded by the recessed end surfaces of the abutted heat insulating tubes. A connection structure for heat-insulating pipes, characterized in that a tube body is inserted and the metal pipes are connected to each other. (2) The connection structure for heat-insulating pipes according to claim 1 of the utility model registration claim, in which metal pipes are connected by welding. (3) The connection structure for heat-insulating pipes according to claim 1 of the utility model registration claim, in which metal pipes are connected to each other by a pipe joint. (4) The insulation pipe connection structure according to claim 1, 2, or 3 of the utility model registration claim, wherein the opening of the side surface of the tube body is performed by cutting the side surface of the tube body. (5) The insulation pipe connection structure according to claim 1, 2, or 3 of the utility model registration claim, wherein the opening of the side surface of the tube body is performed by perforating the side surface of the tube body.