JP3375482B2 - Metal reflective insulation - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a metal reflection type heat retaining device which is mainly used for heat insulation of nuclear power plant equipment, piping and the like.

[0002]

2. Description of the Related Art Conventionally, as a metal reflective type heat retaining device of this type, a metal thin plate such as aluminum foil or stainless foil, which is filled and arranged in a laminated state inside a metal case such as stainless steel,
There are wrinkle-shaped unevenness processing and the wrinkled type that keeps the required distance between the thin plates by the unevenness, and the parallel type that is filled and arranged in parallel without any processing. Proposed and put to practical use.

FIG. 5 shows an example of a "wrinkle-type" metal reflection type heat retaining device for piping. In the figure, 10 is a semi-cylindrical metal case, 10a is an end closure of the case,
Reference numeral 10b is a side closure of the case, and 10c is a hole formed in both the closure parts to the extent that the strength is not insufficient for the purpose of minimizing the heat transfer area.
Is a thin metal plate that is corrugated, 12 is a coupling buckle, and 13 is a spacer.

In the metal reflection type heat retaining device having the above-mentioned structure, the heat radiation of the heat-insulated body is prevented by the reflection effect of the radiative conduction heat by the metal thin plate and the heat insulation effect of the air layer between the metal thin plates, and as a heat insulating material. Fulfills the function of.

[0005]

However, the "wrinkle type" and "parallel type" metal reflection type heat retaining devices have the following problems. (1) Problem of "wrinkle type" Since the structure is such that the irregularities formed on the thin metal plate maintain a constant interval, the heat conduction due to the contact between the thin metal plates affects and the heat insulation performance is deteriorated. There is a problem. In order to reduce the heat conduction due to this contact, it is necessary to make the pitch of the uneven processing rough, but if it is made rough, the metal thin plate will be warped and deformed due to the effect of heat, and the interval between the metal thin plates can be kept constant. There is a problem that the heat conduction increases due to the convection of air, and in the worst case, the thin metal plates come into contact with each other in a large area or in a large area, resulting in a decrease in heat insulation performance.

(2) Problem of "parallel type" The metal reflective type heat retention device of "parallel type" in which metal thin plates are arranged in parallel is excellent in an ideal state because heat conduction due to contact between metal thin plates does not occur. Good heat insulation performance can be expected. However, in an actual heat retaining structure, in order to hold the metal thin plates in parallel, it is necessary to fix each metal thin plate to the inner end surface of the metal case by welding or the like. Therefore, in a heat retaining device having a complicated shape, there is a problem that processing becomes very complicated and the cost becomes high. Also, in a heat insulating device with a large size, there is a risk that the parallel (constant intervals) of the metal thin plates may not be maintained, so a spacer or the like will be provided in the middle part, and heat conduction due to the contact of this spacer will reduce the heat insulation performance. It will be.

The present invention has been made in view of the above problems, and it is a main object of the present invention to provide a metal reflection type heat retention device which is excellent in manufacturing workability and can maximize heat insulation performance. And

[0008]

DISCLOSURE OF THE INVENTION The present invention is a metal reflection type heat retaining device in which a large number of metal thin plates are stacked and arranged inside a metal case, and the metal thin plates are embossed in a lattice pattern. The ribs and the surface portions defined by the grid-like ribs are provided with protrusions that are higher in height than the ribs at different phase portions between the metal thin plates, and the metal thin plates are regulated by the protrusion height. The gist is that they are laminated at intervals.

It is preferable that the grid-like ribs to be embossed on the thin metal plate are V-shaped and the protrusions are conical. But,
The shapes of the ribs and the protrusions are not limited to these.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION As a preferred embodiment of the present invention, as shown in FIGS.
V-shaped ribs 2a and 2b, in which metal thin plates 2 that are stacked and filled in a metal case 1 that is formed in a semi-cylindrical shape so as to surround the are pressed in a lattice pattern at required intervals, and the ribs 2a. , 2b, and a conical projection 2c, which is stamped higher than the ribs, is provided at the center of the lattice surface portion.

According to the above construction, since the metal thin plate 2 is provided with the grid-shaped ribs 2a and 2b by embossing, the strength of the metal thin plate itself can be improved and deformation such as warping due to the influence of heat can be prevented. it can. Especially the ribs 2
When the metal thin plate 2 having a and 2b is filled and arranged in a semicircular metal case, the metal thin plate 2 is easily bent at the ribs 2a in the axial direction of the case, and the ribs 2b in the circumferential direction resist the bending, and Since it is difficult to bend in the middle of the direction rib 2a, it is possible to bend and hold the thin metal plate in a polygonal shape that is concentric with the semi-cylindrical metal case.

On the other hand, the projection 2c formed on the metal thin plate 2 by embossing
By providing the above, it is possible to fill and arrange the metal thin plates inside the case while suppressing heat conduction due to contact as small as possible. Especially when the projection 2c has a conical shape,
It becomes possible to hold the thin metal plates at a constant interval in the point contact state.

[0013]

1 to 3 show an embodiment of the present invention. In the figure, P is a pipe to be a work piece, 1 is a semi-cylindrical metal case formed so as to surround the pipe, and 2 is a thin metal plate arranged in a stacked manner inside the metal case.

The thin metal plate 2 reflects radiant heat on its surface, and an air layer formed between the thin metal plates exerts a heat insulating effect to serve as a heat retaining layer, which has a thickness of 0.05 to.
It is suitable to use a stainless steel plate or an aluminum plate of about 0.1 mm.

On the metal thin plate 2, V-shaped ribs 2a and 2b, which are embossed in a lattice pattern at required intervals, and the ribs 2 are formed.
A conical projection 2c, which is stamped higher than the ribs, is provided at the center of the lattice plane portion partitioned by a and 2b. The V-shaped ribs 2a and 2b stamped on the metal thin plate 2 in a lattice shape are important factors for bending and holding the metal thin plate 2 in a polygonal shape concentric with the cylindrical case. That is, when the thin metal plate is packed and arranged in the cylindrical case, it is easily bent at the rib 2a in the axial direction of the case, the rib 2b in the circumferential direction resists bending, and is hard to bend in the middle of the axial rib. Therefore, the thin metal plate can be bent and held in a polygonal shape concentric with the case.

The interval between the V-shaped ribs 2a and 2b provided in a grid pattern on the thin metal plate 2 is 10 to 70 mm, and the height of the V-shaped rib is about 1 mm, which is suitable for piping. In addition, it is preferable that the conical projection 2c that regulates the interval between the thin metal plates has a diameter of the conical bottom surface of 10 to 15 mm and a height of about 3 to 8 mm in terms of heat insulation performance. It is desirable to reduce the number of the conical protrusions 2c as much as possible from the viewpoint of heat insulation performance. Therefore, the interval between the conical protrusions is 50 to 70 mm.
Is appropriate.

Further, it is preferable that the conical protrusions 2c are provided at different phase portions between the laminated metal thin plates. For example, as shown in FIG. 2, when a metal thin plate is used in which the pitches of the protrusions 2c provided on the lattice plane portion partitioned by the V-shaped ribs 2a and 2b are different in the orthogonal direction, the metal thin plate is It is easy to set the protrusions of adjacent thin metal plates in different phases simply by rotating them by 90 degrees and sequentially laminating them or by sequentially shifting the pitch of the protrusions by 1/2 in the axial direction of the case. it can. The embodiment of FIG. 1 shows a state where metal thin plates are laminated by the latter means.

With the above-mentioned structure, the strength of the metal thin plate itself is improved, deformation such as warping due to the influence of heat is eliminated, and heat conduction due to contact between the metal thin plates is minimized and the surface of the metal thin plate is minimized. The effect of reflecting the radiant heat is effectively exerted, and an excellent heat insulating effect is exhibited.

The metal case for piping is not limited to the semi-cylindrical case, but may be a multi-section cylindrical case such as a three-section or a four-section. Further, like the “wrinkle-type” metal reflection type heat retaining device for piping shown in FIG. 5, it is desirable to make a hole in a portion called a closure so that the strength is not insufficient in order to reduce the heat transfer area.
It is needless to say that the same operational effect as described above can be obtained even in the case of a cubic metal case.

The graph of FIG. 4 shows a heat transmission test (JIS) of the metal reflection type heat retention device according to the present invention and the conventional product (wrinkled type).
A1412 “by a flat plate comparison method in“ Measurement method of thermal conductivity and thermal resistance of heat insulating material ”” is shown for comparison. In this test, the test materials were prepared by using the specified materials shown in Table 1 below and filling and arranging thin metal plates in a cubic shape inside the case.

[0021]

[Table 1]

As shown in the above graph, it was confirmed that the product of the present invention had a smaller heat transmission coefficient than the conventional product and was significantly excellent in the heat insulating effect.

[0023]

As described above in detail, according to the structure of the metal reflection type heat retention device of the present invention, the following effects can be obtained. (1) By providing the metal thin plate with ribs in a grid pattern, the strength of the metal thin plate itself can be improved and deformation such as warping due to the influence of heat can be prevented. (2) Due to the action of the grid-like ribs and projections that bend the metal thin plates in a polygonal shape that is concentric with the cylindrical case, the distance between the metal thin plates is kept constant as a whole, and the air that is effective for the heat insulating effect Layers (constant intervals) can be retained. In addition, in the case where the projection is a conical projection, heat conduction due to contact between the thin metal plates can be made so small that it can be ignored. (3) Even in a metal case having a complicated shape that requires a cutout in a part of the heat retaining device due to a branch pipe, a bent pipe, or a peripheral interference object, a preliminarily stamped metal thin plate is cut into a predetermined shape. Only by doing so, it is possible to easily stack and fill the inside of the case, and it is possible to expect an economic effect that cannot be obtained with the conventional product (parallel type).

[Brief description of drawings]

FIG. 1 is a configuration diagram of a metal reflection type heat retention device showing an embodiment of the present invention.

FIG. 2 is a front view of a thin metal plate.

FIG. 3 is a plan view of a thin metal plate.

FIG. 4 is a graph showing the results of heat-through tests of the product of the present invention and the conventional product.

FIG. 5 is a perspective view of a conventional “wrinkle-type” metal reflective heat retaining device.

[Explanation of symbols]

P piping 1 Semi-cylindrical metal case 2 thin metal plates 2a, 2b V-shaped rib 2c conical protrusion 10 Semi-cylindrical metal case 10a case end closure 10b case side closure 10c hole 11 Wrinkled metal sheet 12 Connection buckle 13 Spacer

Continuation of the front page (56) References JP-A-58-146787 (JP, A) Actually opened 57-38988 (JP, U) Actually opened 62-141996 (JP, U) Actually opened 7-41192 (JP , U) Actual development 60-62697 (JP, U) Actual development 60-156292 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16L 59/00-59/22

Claims (3)

(57) [Claims] 1. A metal reflective type heat retaining device in which a large number of thin metal plates are stacked and arranged inside a metal case,
The metal thin plates have ribs that are embossed in a grid pattern, and the surface portions defined by the grid ribs are different from each other.
A metal reflection type heat retention device, characterized in that a protrusion pressed higher than the rib is provided in the phase portion, and the thin metal plates are laminated at an interval regulated by the height of the protrusion. 2. The metal reflection type heat retention device according to claim 1, wherein the grid-like ribs of a large number of thin metal plates are V-shaped and the projections are conical. 3. The metal case is a multi-division cylindrical case.
The metal reflection type heat retention according to any one of claims 1 to 2.
apparatus.