JP6838500B2 - Double insulated wall structure - Google Patents

Description

The present invention relates to a double insulated wall structure.

A double heat insulating wall structure is known in which an outer pipe and an inner pipe having both ends open are joined at both ends, and a closed space formed between the outer pipe and the inner pipe is decompressed. Patent Document 1 discloses a vacuum double-walled container in which a gap between an outer pipe and an inner pipe is used as a vacuum heat insulating layer.

Japanese Unexamined Patent Publication No. 06-189861

The inventor of the present application makes contact with the outer pipe and the inner pipe on the vertically lower side of the enclosed space in order to prevent the eccentricity of the bellows interposed between the outer pipe and the inner pipe when the double heat insulating wall structure is heated. The support member provided in the above was examined. By providing the support member, it is possible to support the weight of the inner pipe and the load of the contents of the inner pipe when the inner pipe is heated. It has been found that the thermal expansion of the inner tube in the direction of the support member is restricted during heating, the inner tube is eccentric in the vertically upward direction, and the bellows is eccentric accordingly.

The present invention has been made in view of the above problems, and provides a double heat insulating wall structure capable of suppressing eccentricity and breakage of bellows during heating.

The double heat insulating wall structure according to the present invention includes an outer pipe and an inner pipe arranged so that the axial direction is perpendicular to the vertical direction, a bellows that joins both ends of the outer pipe and the inner pipe, and a closed space. A support member in contact with the outer pipe arranged on the vertically lower side in the above, and a bellows arranged in a state of being stretched so as to apply tension in the axial direction to the inner pipe in an unheated state, and predetermined in the radial direction. It is provided with a support member and an inner pipe which are opposed to each other at intervals of.

This double heat insulating wall structure has a predetermined distance between the upper surface of the support member (the surface on the positive side of the z-axis) and the lower surface of the inner pipe (the surface on the negative side of the z-axis) in the unheated state. There is. Therefore, the inner pipe can be expanded evenly in the radial direction of the pipe without deviating from the central axis of the outer pipe and the central axis of the inner pipe. Since the inner tube is evenly expanded in the radial direction, an external force is evenly applied to the bellows, and the eccentricity of the bellows can be suppressed. As a result, it is possible to prevent the bellows from being eccentrically damaged during heating.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a double heat insulating wall structure capable of suppressing eccentricity and breakage of bellows during heating.

It is sectional drawing which shows typically the structure of the double insulation wall structure which concerns on this embodiment. It is sectional drawing which follows the line II-II of FIG. It is sectional drawing which shows typically the flow which joins the outer pipe and the inner pipe of the double insulation wall structure which concerns on this embodiment through a bellows. It is sectional drawing which shows typically the state at the time of heating of the double insulation wall structure which concerns on this embodiment. It is sectional drawing of the double insulation wall structure along the VV line of FIG. It is sectional drawing which shows typically the state at the time of non-heating and the state at the time of heating of the double insulation wall structure which concerns on a comparative example. FIG. 6 is a cross-sectional view taken along the line VII-VII of FIG.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. Also, the drawings have been simplified as appropriate to clarify the description.
As a matter of course, the right-handed xyz coordinates shown in FIGS. 1 to 7 are for convenience to explain the positional relationship of the components. Usually, the z-axis plus direction is vertically upward, and the xy plane is a horizontal plane, which is common between drawings. The alternate long and short dash line shown in FIGS. 1 to 7 indicates the center line.

FIG. 1 is a cross-sectional view (plane on the positive side of the y-axis) schematically showing the configuration of the double heat insulating wall structure according to the present embodiment, and FIG. 2 is a cross-sectional view taken along the line II-II of FIG. (The surface on the positive side of the x-axis). The double heat insulating wall structure 1 shown in FIGS. 1 and 2 is in an unheated state. The double heat insulating wall structure 1 can be used as a heating furnace. As shown in FIGS. 1 and 2, the double heat insulating wall structure 1 includes an outer pipe 11, an inner pipe 12, a support member 13, and a bellows B.

As shown in FIGS. 1 and 2, the outer pipe 11 and the inner pipe 12 are cylindrical members whose ends are partially or wholly opened. The bellows B is a flexible telescopic tube that expands and contracts. The support member 13 is a heat insulating material having a U-shaped upper surface and lower surface. Specifically, the lower surface of the support member 13 has a shape corresponding to the shape of the bottom surface of the outer tube 11, and the upper surface of the support member 13 has a shape corresponding to the shape of the bottom surface of the inner tube 12.

In the present embodiment, the outer tube 11, the inner tube 12, and the bellows B are made of metal. The metal constituting the outer pipe 11, the inner pipe 12, and the bellows B includes, for example, stainless steel, steel, and titanium. The support member 13 is a heat insulating material. The heat insulating material is a material having a lower thermal conductivity than the outer pipe 11 and the inner pipe 12, and includes, for example, refractory bricks.

As shown in FIG. 1, the bellows B joins the outer tube 11 and the inner tube 12. In FIG. 1, the inner tube 12 is supported by the tension of the bellows B. For example, welding can be used to join the outer pipe 11 and the inner pipe 12 to the bellows B.

As shown in FIGS. 1 and 2, a closed space 14 is formed between the outer tube 11, the inner tube 12, and the bellows B. Space 14 is a decompressed vacuum space. That is, the outer tube 11 and the inner tube 12 are insulated by a vacuum space. The outside of the outer pipe 11 is the outside air. The inside of the inner pipe 12 is an accommodation space 15 for accommodating the contents when the double heat insulating wall structure 1 is heated.

As shown in FIGS. 1 and 2, a support member 13 in contact with the outer pipe 11 is arranged on the vertically lower side in the closed space 14. When arranging the support member 13, a predetermined distance h is provided between the upper surface of the support member 13 (the surface on the positive side of the z-axis) and the lower surface of the inner pipe 12 (the surface on the negative side of the z-axis). By providing a predetermined distance h, it is possible to heat the double heat insulating wall structure 1 and suppress the eccentricity of the bellows B when the inner pipe 12 undergoes thermal expansion. The details of the mechanism for suppressing the eccentricity of bellows B will be described later.

Next, the flow of joining the outer pipe 11 and the inner pipe 12 in the double heat insulating wall structure 1 via the bellows B will be described below.
FIG. 3 is a cross-sectional view schematically showing a flow of joining the outer pipe and the inner pipe of the double heat insulating wall structure according to the present embodiment via bellows. FIG. 3A shows a state before the outer pipe 11 and the inner pipe 12 are joined via the bellows B. FIG. 3B shows a state after the outer pipe 11 and the inner pipe 12 are joined via the bellows B. The double heat insulating wall structure 1 shown in FIG. 3 is a cross-sectional view schematically showing a non-heated state.

As shown in FIG. 3A, the bellows B is in a state of natural length Lc1 before joining the right ends of the outer tube 11 and the inner tube 12. FIG. 3A shows the left end of the outer pipe 11 and the inner pipe 12 while supporting the inner pipe 12 by applying a force in the F1 direction (upward white arrow, z-axis positive direction) using the beam S. The left end is joined via a bellows B.

Next, as shown in FIG. 3A, the right end of the outer pipe 11 and the right end of the inner pipe 12 are joined via the bellows B. First, the inner pipe 12 is supported by the beam S. Specifically, the inner pipe 12 is supported by lifting the inner pipe 12 in the F1 direction using the beam S. While maintaining the state in which the inner pipe 12 is supported by the beam S, the bellows B is displaced in the axial direction (F2 direction, x-axis forward direction). Tension is applied to the bellows B by axially displacing the bellows B.

In this way, while applying tension to the bellows B, the right end of the outer pipe 11 and the right end of the inner pipe 12 are joined via the bellows B. Here, when no tension is applied to the bellows B, the bellows B bends. That is, if no tension is applied to the bellows B, the inner tube 12 is eccentric to the lower surface side of the outer tube 11. In the present embodiment, the eccentricity of the inner tube 12 can be suppressed by applying tension to the bellows B.

FIG. 3B shows a double heat insulating wall structure 1 joined through the steps of FIG. 3A. Since the bellows B is in a state where tension is applied, the state of the bellows B is a state Lc2 that is more stretched than the natural length Lc1 (Lc1 <Lc2). As shown in FIG. 3B, since the inner tube 12 is in a state where tension is applied in the axial direction due to the tension of the bellows B, the upper surface of the support member 13 (the surface on the positive side of the z-axis) and the lower surface of the inner tube 12 A predetermined distance h is provided between the surface and the surface on the negative side of the z-axis.

As shown in FIG. 3B, a closed space 14 is formed between the outer pipe 11 and the inner pipe 12 joined via the bellows B. The space 14 is decompressed by a vacuum pump to become a vacuum space. As a result, the outer tube 11 and the inner tube 12 are vacuum-insulated.

Here, the problem to be solved by the present invention will be described in detail. The inventor of the present application has provided a support provided on the inner bottom surface of the outer pipe so as to be in contact with the inner pipe in order to prevent eccentricity of the bellows interposed between the outer pipe and the inner pipe when the double heat insulating wall structure is heated. The arrangement of the members was examined.
FIG. 6 is a cross-sectional view schematically showing the state of the double heat insulating wall structure according to the comparative example when not heated and when heated, and FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. .. 6 (a) and 7 (a) show the configuration in the non-heated state, and FIGS. 6 (b) and 7 (b) show the state in which the inner tube 102 is thermally expanded in the heated state.

As shown in FIGS. 6 (a) and 7 (a), the support member 103 is provided so that the inner pipe 102 and the support member 103 are in contact with each other when not heated. The support member 103 can support the weight of the inner pipe 102 and the load of the contents of the inner pipe 102. However, as shown in FIGS. 6 (b) and 7 (b), the inner tube 102 and the support member 103 are in contact with each other from the time of non-heating, so that the inner tube 102 is thermally expanded in the direction of the support member 103 during heating. It has been found that the inner tube 102 is eccentric in the upper direction (F4 direction) and the bellows B is eccentric. The eccentricity of the bellows B means that the central axis when not heated and the central axis when heated are displaced and do not match.

Next, the mechanism for suppressing the eccentricity of the bellows B in the double heat insulating wall structure 1 according to the present embodiment will be described.
FIG. 4 is a cross-sectional view schematically showing a state of the double heat insulating wall structure according to the present embodiment at the time of heating, and FIG. 5 is a double heat insulating wall structure along the VV line of FIG. It is a cross-sectional view of. In FIGS. 4 and 5, the position of the inner tube in the unheated state is indicated by a chain double-dashed line.

When the double heat insulating wall structure 1 shown in FIGS. 1 and 2 is heated, the inner pipe 12 thermally expands as shown in FIGS. 4 and 5. Specifically, when the inner tube 12 is heated, the inner tube 12 thermally expands in the radial direction and the axial direction (F3 direction). As a result, the distance between the outer tube 11 and the inner tube 12 is narrowed, but in the unheated state, the upper surface of the support member 13 (the surface on the positive side of the z-axis) and the lower surface of the inner tube 12 (the surface on the negative side of the z-axis) Since the inner pipe 12 has a predetermined distance h between the two, the inner pipe 12 can be freely thermally expanded in the radial direction. In other words, the inner pipe 12 can be expanded evenly in the radial direction of the pipe without deviating from the central axis of the outer pipe 11 and the central axis of the inner pipe 12. The support member 13 can support the weight of the inner pipe 12 and the load of the contents of the inner pipe 12 when the diameter of the inner pipe 12 is expanded due to thermal expansion.

With such thermal expansion of the inner tube 12, axial displacement and radial displacement occur in the bellows B joined to the inner tube 12 (Lc3 <Lc2). As described above, since the central axis of the outer tube 11 and the central axis of the inner tube 12 do not deviate from each other and the inner tube 12 expands evenly in the radial direction, the external force is evenly applied to the bellows B. It takes. That is, the eccentricity of the bellows B can be suppressed, and the destruction of the bellows B due to the eccentricity is unlikely to occur.

From the above, in the present embodiment, the outer pipe 11 and the inner pipe 12 arranged so that the axial direction is perpendicular to the vertical direction, the bellows B for joining both ends of the outer pipe 11 and the inner pipe 12, and the bellows B. A support member 13 in contact with the outer pipe 11 arranged vertically below in the closed space 14 and a bellows arranged in a state of being stretched so as to apply an axial tension to the inner pipe 12 in an unheated state. B is provided with a support member 13 and an inner pipe 12 facing each other at predetermined intervals in the radial direction. With such a configuration, it is possible to provide a double heat insulating wall structure capable of suppressing eccentricity and damage of the bellows B during heating.

The present invention is not limited to the above embodiment, and can be appropriately modified without departing from the spirit.

1,100 Double insulation wall structure 11,101 Outer pipe 12,102 Inner pipe 13,103 Support member 14 Sealed space 15 Confined space B Bellows S Beam

Claims (1)

A double insulation wall structure in which the enclosed space between the outer pipe and the inner pipe is decompressed.
The outer pipe and the inner pipe are arranged so that the axial direction is perpendicular to the vertical direction.
The outer pipe and the inner pipe are joined via bellows at both ends.
A support member in contact with the outer pipe is arranged on the vertically lower side in the closed space.
In the unheated state, the bellows are arranged in an extended state so that tension is applied to the inner tube in the axial direction, and the support member and the inner tube face each other with a predetermined distance in the radial direction. ing,
Double insulated wall structure.

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