JP2001082681A - Heat insulating material and composite heat insulating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite heat insulating material showing excellent heat insulating performance even for a heat insulating objective structure an external wall surface to arrange the heat insulating material on of which has irregularities as well as to use as a heat insulating and reserving material or a heat insulating cooling material in an extensive temperature region. SOLUTION: A heat insulating material 12 constituted by including a porous ceramic granular body and/or a hollow ceramic granular body 12b in a surrounding body 12a made of a metallic sheet or an inorganic fiber sheet so that a percentage of void in the surrounding body becomes 30-85% is made a lower side heat insulating element 16a, and a composite heat insulating material 10 constituted by laminating an upper side heat insulating material 16b on it is arranged on an external wall surface 100 of a heat insulating objective structure,.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sintering furnace used for sintering electric parts such as plasma displays, cathode ray tubes and ceramics substrates, and a steel and steel field.
The present invention relates to a heat insulating material for heat insulating a high-temperature structure or a low-temperature structure such as a drying furnace, a baking furnace, a refrigerated container, a cold storage device or a container used in chemical material processing and food processing.

[0002]

2. Description of the Related Art Conventionally, heat insulation of a structure having a high temperature, such as a drying furnace or a baking furnace, or a structure having a low temperature, such as a cold storage container, has been carried out by using a cotton-like material made of mineral fibers such as mineral cotton and ceramic fibers. This is done by using a sheet, felt-like sheet or molded block-like material as insulation and placing it outside the walls defining the hot or cold structure, i.e. between the structure and the surrounding atmosphere. I was For example, when the inorganic fiber sheet is arranged and insulated, the thickness of the inorganic fiber sheet is limited to 3 to 100 mm due to manufacturing restrictions.
In order to obtain an effective heat insulating effect, the layers need to be laminated to a thickness of 200 mm or more. Also, in order to improve the appearance, the surface that comes into contact with the outside air around the heat insulating material, that is, the surface farthest from the surface that contacts the high-temperature structure that is the object of heat insulation and heat retention (this surface is also referred to as the “outer surface”) In order to improve the quality, a plate-like material such as a decorative board is often provided.

[0003]

Generally, the outer surface of a wall constituting a main body of a high-temperature structure such as a high-temperature furnace or a low-temperature structure such as a cooling device (this surface is also referred to as an "outer wall surface") is Having irregularities due to members constituting the structure,
Often not flat. For example, the irregularities are formed by projecting the heads of the bolts from the outer wall surface, or by removing pipes or U-shaped steel material for passing cooling water or protecting electrical wiring. It is formed by attaching to a wall surface. In some cases, the piping extends outward from the inside of the structure via the outer wall surface due to design restrictions.

[0004] If the height difference of the portion where the unevenness is formed is small, the unevenness is absorbed by the compressive elasticity of the inorganic fiber sheet, so that the flatness of the outer surface of the heat insulating material is ensured,
Therefore, it is possible to arrange the decorative board without any problem.
However, the height difference between the irregularities is large.
If it exceeds 0 mm, absorption by the inorganic fiber sheet becomes difficult, and as a result, irregularities on the outer wall surface also appear on the outer surface of the heat insulating material, so that the decorative board cannot be arranged.
In addition, if the heat insulating material does not follow the unevenness and a gap is formed between the heat insulating material and the outer wall surface, the heat insulating from the gap may reduce the heat insulating effect.

Therefore, for example, it has been practiced to fill the concave portions with rock wool to eliminate or reduce the height difference between the concave and convex portions, and then arrange the inorganic fiber sheet. However, the work of packing rock wool is not always advantageous in terms of efficiency. In addition, there is also a problem that dust is generated from rock wool during construction and the working environment is deteriorated.

[0006] As another method, there is a method in which a block-shaped heat insulating material made of an inorganic fiber sheet is cut into an appropriate shape and dimensions, and the cut and arranged pieces are arranged so as to conform to the uneven shape to flatten the outer surface. However, in the combination of the cut block-shaped materials, there is a possibility that a gap may be formed between the heat insulating material and the outer wall surface depending on whether the concave portion has a curved surface, for example, when the concave portion has a curved surface. The problem caused by the gap is as described above. In addition, it is complicated to cut the heat insulating material every time the construction is performed according to the unevenness, and the construction efficiency is deteriorated. Further, there is a problem that dust generated from the heat insulating material at the time of cutting deteriorates the working environment.

When the pipe extends from the outer wall,
An opening corresponding to the cross-sectional shape of the pipe is provided in the heat insulating material, and the pipe is penetrated through the opening, so that the entire outer wall surface excluding the pipe portion is covered with the heat insulating material without a gap. However, a gap is easily formed between the opening of the heat insulating material and the pipe, and the gap may reduce the heat insulating effect. Therefore, rock wool or the like is filled in the gap, but the problem of such an operation is as described above.

As described above, in the case where the outer wall surface of the structure to be thermally insulated is not flat but has irregularities, it is difficult to arrange the heat insulating material without lowering the heat insulation effect and the construction efficiency. In view of such a situation, a first object of the present invention is to provide a heat insulating material that can be installed so as to exhibit a good heat insulating effect regardless of the structure of the outer wall surface of a structure to be thermally insulated. And

[0009] For example, regarding a high-temperature furnace, a portion having a high temperature and a portion having a low temperature generally occur on the outer wall surface. The heat conductivity of the heat insulating material composed of inorganic fibers exemplified above has a temperature-dependent characteristic. As the temperature increases, the heat conductivity increases and the heat insulating effect decreases. Therefore, the temperature difference generated on the outer wall surface of the furnace hinders the uniformity of the heat insulating effect provided by the heat insulating material disposed therearound, and as a result, a high temperature portion and a low temperature portion occur on the outer surface of the heat insulating material. There are cases. This reduces the design outer surface temperature, ie, the expected temperature of the outer surface of the insulation by, for example, 40
Even if the heat insulating material is set at a temperature of not more than 70 ° C., the temperature becomes close to 70 ° C. in a certain place, and a predetermined heat insulating effect cannot be obtained, which causes a problem that the heat insulating performance cannot be made uniform.

Accordingly, the present invention provides a method for controlling the temperature of the outer surface of a heat insulating material that covers the outer wall of a furnace due to the temperature dependence of the thermal conductivity of the heat insulating material when the temperature of the outer wall of the high temperature furnace varies greatly. It is a second object of the present invention to provide a composite heat insulating material for keeping heat or cooling, which eliminates non-uniformity of heat insulation performance, that is, variation, and shows better heat insulation properties than conventional heat insulating materials made of inorganic fibers.

[0011]

In order to achieve the first object, the present invention provides a porous ceramic-based granular material and / or a hollow ceramic-based granular material in an enclosure made of a metal sheet or an inorganic fiber sheet. A thermal insulation comprising the body such that the porosity in the enclosure is between 30 and 85%.

[0012] This heat insulating material comprises a porous ceramic-based granular material and / or a hollow ceramic-based granular material having a heat insulating effect in an envelope made of a sheet material having flexibility or flexibility. It is characterized in that it is filled in a state where voids are left, that is, in an appropriately sparse state. Due to this feature, the whole heat insulating material is appropriately deformable, that is, has a deformable shape.

The "enclosure" constituting the heat insulating material defines a space in which the shape can be changed and the volume can be changed in some cases, and the porous ceramic-based granular material and And / or hollow ceramics-based granules, which are enclosed so that they do not leak out of the space. The sheet constituting the enclosure is preferably a metal sheet or an inorganic fiber sheet having flexibility.

When a metal sheet is used, the metal sheet is, for example, a stainless steel sheet, for example, 0.0%.
Preferably, it has a thickness of 1 to 0.18 mm. Since the metal sheet is gas-impermeable, if an enclosure is formed using this and the joint between the sheets is made airtight by welding or the like, gas can enter and exit the enclosure substantially. No, a closed space isolated from the outside can be formed. In that case, the thermal insulation will be deformable by the compression or expansion of the volume of gas (eg air) present in the enclosure and the flow of porous and / or hollow ceramic-based particles in the enclosure. .

When an inorganic fiber sheet is used, the inorganic fiber sheet is a nonwoven fabric, a woven fabric, a felt, a mesh, or the like, and is preferably made of an alumina fiber, a silica fiber, a carbon fiber, or the like. In particular, since the alumina fiber has a high heat-resistant temperature as high as 1000 ° C., it can be conveniently used to insulate a high-temperature insulating structure. The thickness of the inorganic fiber sheet is 0.5 to 1.6 mm.
It is preferable that the basis weight is 200 to 1500 g
/ M ² .

The inorganic fiber sheet has an opening area of 80 to 10000 μm ² , provided that the porous ceramic-based particles and / or the hollow ceramic-based particles contained in the enclosure do not leak. It is preferable that the portions are formed at a rate of 100 to 12000 pieces / cm ² . Since the inorganic fiber sheet has gas permeability, the surrounding body is surrounded by surrounding gas (for example, air).
May enter and exit the enclosure, and may be deformed by the flow of the porous ceramic-based particles and / or the hollow ceramic-based particles in the enclosure. Therefore, the heat insulating material having the inorganic fiber sheet as the surrounding body has a greater deformability than the heat insulating material having the metal sheet as the surrounding body.

The envelope is filled with porous ceramic-based granules and / or hollow ceramic-based granules (these are sometimes collectively referred to as "ceramic-based granules").

The ceramic material constituting the ceramic-based particles preferably contains, for example, 80 to 95% by weight of silica (SiO ₂ ) and 20 to 5% by weight of alumina (Al ₂ O ₃ ). The granular material is 100 ~
It is preferable to use one having a size of 1000 mesh.

The porous ceramic-based granular material is a sponge-like granular material having a large number of pores formed on the surface and inside of one granular material. Most of the holes communicate with each other to form an open cell, but in some cases, the holes are separated by a wall. In the porous ceramic-based granular material,
The ratio of the whole pores in one porous granular material is 30 to 70
It is preferable that the volume percentage (ie, the porosity is 30 to 70%). The pores formed in the porous ceramics-based granular material have a volume of 1 × 10 ⁻⁹ mm ^{3 to} 5 × 1 per one hole.
It is preferably 0 ^-1 mm ³ . Porous ceramics-based granular material, for example, when dropping the molten ceramics drops in the atmosphere, contact with a high-speed gas flow,
It is obtained by foaming or spheroidizing a ceramic droplet and then rapidly cooling it.

On the other hand, the hollow ceramic-based granules are, for example, foamed hollow ceramic-based granules, in which one or a plurality of hollow portions are independently formed in one granule, and the hollow portions communicate with the outside. That is not what you do. Therefore,
The fluid cannot substantially penetrate into the hollow portion of the hollow ceramic-based granular material. Further, in the hollow ceramics-based granular material, a single hollow portion may be formed by connecting a plurality of small holes.

The ratio of the hollow portion to the hollow ceramic particles is 20 to 60% by volume (that is, the porosity is 20 to 60%).
It is preferable that The hollow portion existing in the hollow ceramics granular material has a volume of 1 × 10 ⁻⁹ mm ³ or more.
It is preferably 3 × 10 ⁻³ mm ³ , and 1 × 10 ⁻⁹ mm ³ to
More preferably, it is 1 × 10 ⁻⁶ mm ³ . The hollow ceramic-based granular material can be obtained, for example, by pulverizing a microporous heat-insulating material described in JP-A-63-252982 or JP-A-7-330559 to form a granular material. Granules obtained by pulverization, the hollow ceramic-based granules do not dissociate into individual particles, there are cases where the particles are agglomerated particles, as long as the mass has a size of 100 to 1000 mesh, Such lumps can also be used. The hollow ceramics-based granular material is equivalent to a pre-processed product of a board sold as a WDS board (trade name) by Harima Ceramics, or is sold as a powder of Microtherm (trade name) by Aerosil Japan. ing.

In some cases, the porous ceramics-based particles may include, for example, hollow ceramics-based particles accidentally formed during the manufacturing process. Ceramic particulates may be included. Alternatively, in a granular material which is difficult to be divided into either of them, for example, a granular material in which a plurality of independent hollow portions are formed, one hollow portion communicates with the outside and has a slight fluid permeability. Granules may be formed. Therefore, in the present specification, “and” included in the term “porous ceramic-based granules and / or hollow ceramic-based granules” are included.
Is not only when both are intentionally mixed and used,
It is used for the purpose including the case where both are accidentally mixed as described above, and also including the case where a granular material which is difficult to distinguish from both is used.

The sparseness of the porous ceramic particles and / or the hollow ceramic particles in the enclosure is as follows:
Expressed by porosity. The porosity can be calculated by dividing the volume occupied by the porous ceramic particles and / or the hollow ceramic particles contained in the space defined in the enclosure by the maximum volume of the space. The maximum volume of the space, when the enclosure is formed of a metal sheet, in consideration of the fact that the enclosure is liquid-tight, under the condition that the sheet does not elongate in the enclosure, for example, It is determined by filling the water to the maximum and measuring its volume. Further, when the envelope is formed of an inorganic fiber sheet, for example, assuming that the sheet has been replaced with a metal sheet, the volume capable of filling the envelope with water, for example, as much as possible corresponds to the maximum volume of the space. I do. If the sheet constituting the envelope does not substantially expand, a space having substantially the same maximum volume is formed in the envelope of the metal sheet and the envelope of the inorganic fiber sheet having the same shape and dimensions. Will be formed.

The heat insulating material of the present invention can form a substantially flat surface on the outer wall surface by arranging a plurality of members having different shapes and dimensions in accordance with the uneven shape of the outer wall surface. The heat insulating material of the present invention containing fine granular materials,
Since it can be deformed by the fluidity of the granular material, it can easily follow the uneven shape of the outer wall surface. Therefore, the adhesion between the heat insulating material of the present invention and the outer wall surface is extremely excellent.

The heat insulating material of the present invention has a structure in which porous ceramic-based particles and / or hollow ceramic-based particles are present in the enclosure, and the structure effectively suppresses dust generation due to scattering of the particles. I do. Therefore, the use of the heat insulating material of the present invention can prevent the working environment from being deteriorated when the heat insulating material is installed. In particular, when the enclosure is formed of a metal sheet, an excellent dust suppression effect is obtained due to its airtightness, and the dust generation level (20 m) of the heat insulating material formed using the metal sheet is obtained. / seconds airflow when blown heat-insulating material, the number dimensions than dust 1μm contained in the air per 1 m ³ in the downstream portion of the air flow) can be suppressed to about 0-100 cells / m ^3. On the other hand, when the enclosure is formed of an inorganic fiber sheet, the dust generation level of the heat insulating material is 1000 to 1000.
Becomes large as 5000 / m ^3, dust level of conventional insulation material made of inorganic fiber sheet is not less more than 100,000, in view of the fact that the dust level greater is in cutting it, It can be said that a heat insulating material whose surrounding body is an inorganic fiber sheet also exhibits an excellent dust generation suppressing effect.

In the actual construction, if a plurality of types of heat insulating materials having different shapes and dimensions are prepared in advance and an appropriate material can be selected according to the shape of the outer wall surface of the structure to be thermally insulated, efficient heat insulation can be achieved. Materials can be constructed.

It is also possible to increase the size of the heat insulating material of the present invention, or to laminate a large number of the heat insulating materials, and to insulate the structure to be thermally insulated alone. However, considering that the porous ceramic-based granules and / or the hollow ceramic-based granules are expensive and that it takes time to produce the enclosure, it is not economical to insulate the structure by itself. There are cases. Therefore, it is preferable that the heat insulating material of the present invention is mainly used for forming a flat surface on an outer wall surface having irregularities, and another heat insulating material that can be applied on the flat surface is disposed on the flat surface. Generally, the use of a heat insulating material that can be applied on a flat surface, for example, a plate-shaped or block-shaped heat insulating material, is advantageous in terms of cost. That is, by using the heat insulating material of the present invention as the lower heat insulating element and laminating an appropriate upper heat insulating element thereon, a composite heat insulating material that is economical and has good workability can be obtained.

In this specification, the terms "lower" and "upper" do not indicate absolute upper and lower directions, and the terms "lower" and "lower" are close to the outer wall surface of the target structure. The terms side, "upper" and "upper" are used to indicate the side remote from the outer wall.

The upper heat-insulating element constituting the composite heat-insulating material is, for example, preferably formed by laminating a plurality of laminating units each having a heat-insulating plate and an inorganic fiber sheet so that the heat-insulating plate is on the lower side. . The insulating plate may be, for example, a metal plate and a mica insulating plate, and the inorganic fiber sheet is formed of a large number of voids, preferably fines, formed by using fibers made of an inorganic material having heat resistance and / or low temperature resistance. It is a sheet having voids, for example, a nonwoven fabric, a woven fabric, a felt, a mesh, or the like. However, the upper heat insulating element is not limited to the laminated unit,
Conventionally used insulation may be employed as the upper insulation element.

The second object of the present invention can be achieved by disposing a thermally conductive anisotropic sheet having a relatively larger thermal conductivity in the plane direction than the thickness direction in the composite heat insulating material. The heat conduction anisotropic sheet is disposed below the lower heat insulating element when insulating the structure to be thermally insulated at a high temperature. Place on top of timber.

The heat conductive anisotropic sheet has the property of transmitting the heat applied thereto preferentially in the plane direction rather than in the thickness direction. Therefore, for example, when the heat conduction anisotropic sheet is arranged so as to be in contact with the outer wall surface of the high-temperature furnace, even when the temperature of the outer wall surface of the furnace varies, the heat is conducted in the plane direction, so that the temperature of the entire surface of the sheet is reduced. The variability is reduced and preferably substantially uniform. As a result, the heat-insulating element provided on the heat-conducting anisotropic sheet can exert a heat-insulating action on the heat-conducting anisotropic sheet whose surface temperature is substantially uniform, so that the outer surface of the composite heat insulating material, That is, the temperature variation is reduced even on the surface farthest from the heat conductive anisotropic sheet.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a heat insulating material and a composite heat insulating material according to the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the composite heat insulating material of the present invention. This composite heat insulating material (10) is composed of a heat conductive anisotropic sheet (1
1), the lower insulation element (16a) and the upper insulation element (16
b), and a decorative plate is laminated as the outermost layer (S1). The lower heat-insulating element (16a) is the heat-insulating material (12) of the present invention comprising a porous ceramic-based granule and / or a hollow ceramic-based granule (12b) in an envelope (12a) made of a sheet; Upper insulation element (16
b) is composed of four laminated units (15) in which a heat insulating plate (13) and an inorganic fiber sheet (14) are laminated. FIG. 1 shows a state in which the heat conductive anisotropic sheet (11) is arranged adjacent to a high-temperature structure to be insulated and kept warm, for example, an outer wall surface (100) of a high-temperature furnace to perform adiabatic heat keeping. Is schematically shown.

The heat insulating material (12) has a porous ceramic-based granular material and / or a hollow ceramic-based granular material (12b) in an envelope (12a) made of a sheet, and the porosity in the envelope (12a) is within a predetermined range. It has a variable form. The sheet constituting the enclosure (12a) is preferably a metal sheet or an inorganic fiber sheet having flexibility.

When the enclosure (12a) is formed of a metal sheet, the metal sheet is made of, for example, stainless steel as described above, and preferably has a thickness of, for example, 0.01 to 0.18 mm. If the thickness is less than 0.01 mm, the strength is small and the durability is inferior. If the thickness is more than 0.18 mm, the flexibility is reduced, the deformability of the whole heat insulating material is reduced, and the heat insulating material is uneven on the outer wall surface. It is difficult to follow. A plurality of metal sheets may be stacked and used to improve the strength.

When a metal sheet is used, it is preferable that one surface of the metal sheet has a high thermal reflectance by mirror finishing or the like, and the surface having the high thermal reflectance is the outer surface of the enclosure. . When the heat reflectance outside the enclosure is high, there is an advantage that the radiant heat from the furnace is reflected by the heat insulating material (12), and the heat insulating performance of the heat insulating material (12) is improved. In the present specification, “high heat reflectance” of a surface corresponds to “low heat emissivity” of the surface.
Therefore, it is preferable that the surface of the metal sheet having a high thermal reflectance has a low thermal emissivity whose thermal emissivity is 0.1 or less, and such a thermal emissivity is determined by mirror finishing or the like. The average roughness Ra of the surface can be at most 4 μm, preferably at most 0.2 μm.

When the enclosure (12a) is an inorganic fiber sheet, air is supplied to or discharged from the space in the enclosure (12a) through a gap existing in the inorganic fiber sheet. Therefore, the heat insulating material (12) is deformed by the inflow and outflow of air, and its deformability is greater than that in which the enclosure (12a) is a metal sheet. As described above, the inorganic fiber sheet is preferably a nonwoven fabric, woven fabric, felt, mesh, or the like made of alumina fiber, silica fiber, carbon-based fiber, or the like.

The sheet has openings each having an opening area of preferably 80 to 10000 μm ² , more preferably 1000 to 5000 μm ² , preferably 100 to 12000 / cm ² , more preferably 10
It is formed at a rate of 00 to 6000 / cm ² . If the openings are small or the number of openings is small, smooth supply and exhaust of air in the enclosure will not be performed, and the deformability will be reduced. If the openings are large or the number of openings is large, there is a problem that a part of the ceramic-based granular material leaks from the openings. As an inorganic fiber sheet suitable for forming the envelope (12a), there is "Siltex Cross (trade name)" manufactured by Nichias. A plurality of inorganic fiber sheets may be laminated and used. Moreover, you may laminate | stack and use an inorganic fiber sheet and a metal sheet.

The heat insulating material (12) is a prismatic or cylindrical container as shown in FIG. 2 using the above-mentioned metal sheet or inorganic fiber sheet and having a ceramic-based granular material inlet. And make this an enclosure (12
In step a), the ceramic-based particles are filled so that the porosity in the space is 30 to 85%, and finally, the inlet of the ceramic-based particles is sealed and formed.

The ceramic particles (12b) are sufficiently dried and filled in the enclosure (12a). Ceramic granules (12
Specifically, the water content of b) is preferably 8% by weight or less. As mentioned above, the ceramic-based granular material
It is preferably formed of a ceramic material containing silica and alumina, and its size is preferably 100 to 1
000 mesh. If the size of the granular material is smaller than 1000 mesh, the granular material may leak from the surrounding body, and the dust may cause a problem of deterioration of work efficiency and work environment. Further, the fine granular material easily adheres or stays on the outer wall or the corner of the transfer container, so that the transfer container is easily contaminated, and, for example, the measured granular material cannot be completely transferred to another container or the like. There is a possibility that the work efficiency at the time of transportation and transfer may be deteriorated, such that the target amount of granular material cannot be accurately filled in the enclosure. When a granular material having a size larger than 100 mesh is used, a large void is generated between the granular material and the granular material, and convection of air is generated in the void, whereby the heat insulating performance of the entire thermal insulating material may be reduced. is there.

The heat insulating material (12) has a porosity of 30 to 85%.
The ceramic-based granular material (12b) is filled so that
If it exceeds 85%, there is a problem that the ceramic granules in the heat insulating material (12) become too sparse, convection of air is generated in the enclosure, heat conductivity is increased, and heat insulation performance is reduced. In this case, the ceramic granules become too dense and the heat insulating material (12) hardly deforms, which is not preferable. As described above, the ceramics-based granular material is silica 80-
When the porosity is formed of a material containing 95% by weight and 20 to 5% by weight of alumina, the porosity is determined by setting the packing density (mass of ceramic particles in the enclosure / maximum volume of space in the enclosure) to 80 to 50%. This can be achieved by setting the pressure at 300 kg / m ³ .

When the sheet is a metal sheet, the seam (sealing portion) of the sheet in the enclosure (12a) is as follows.
Seal with mechanical fastening means such as rivets, heat-resistant adhesives, or spot or line welding
b) should not leak. Sealing by glue or welding is gas tight, thus allowing the enclosure to be an isolated space. When the sheet is an inorganic fiber sheet, the sheet may be stitched with a heat-resistant thread or sealed with a heat-resistant adhesive. Alternatively, as long as the ceramic-based granules do not leak, the ceramic-based granules may be housed in an intermediate portion of a tubular body whose both ends are open, and a material in which both ends are tied with heat-resistant yarn may be used as a heat insulating material.

The shape and dimensions of the enclosure can be selected according to the shape of the outer wall surface of the structure to be thermally insulated. In order to prevent the heat insulating material (12) from buckling when a load is applied and to facilitate the production of the heat insulating material (12), the heat insulating material (12) is, for example, shown in FIG. In the case of a prismatic shape as shown, the width W and the depth T are, for example, 30
2 to 200 mm, and the height H is preferably, for example, 30 to 150 mm. In the case of a cylindrical shape as shown in FIG. 2B, for example, the diameter D is 30 to 200 mm, and the height L is 30.
It is preferable to set it to 150 mm.

If the enclosure (12a) of the insulation (12) is made of a gas-impermeable material, such as a metal sheet, the insulation (12) may contain argon, carbon dioxide, helium, and nitrogen. May be filled with an inert gas. Since an inert gas has a higher heat insulating effect than air, such a heat insulating material provides better heat insulating performance.

When the enclosure (12a) of the heat insulating material (12) is made of a gas-impermeable material such as a metal sheet, and the heat insulating material (12) does not require great deformability, the heat insulating material (12) The inside of (12) may be in a vacuum state of 100 Torr or less, preferably 10 Torr or less, or a reduced pressure state of 450 Torr or less, so that the heat insulating performance of the heat insulating material (12) can be further improved. Such a heat-insulating material results in a solid block and can be used, for example, in flat parts of the outer wall of a furnace.

As the heat insulating material (12), materials having different shapes and / or dimensions are arranged in accordance with the uneven shape of the outer wall surface. As shown in FIG. 3, when the outer wall surface (200) has a convex portion, a heat insulating material (12) having a small height is disposed at the convex portion, and a heat insulating material (12) having a large height is provided at other portions. 12) is arranged, and in the portion where the convex portion has the inclined surface, the surface of the heat insulating material in contact with the inclined surface is deformed along the inclined surface,
Alternatively, by forming the heat insulating material into a shape having an inclined surface, the entire heat insulating material (12) constitutes a lower heat insulating element (16a) having a flat upper surface. Since the heat insulating material (12) has a variable shape, it can be arranged so as to be in close contact with each other. For example, when the cylindrical heat insulating material (12) is arranged, the form viewed from the top is a regular hexagon. Form (Honeycomb)
The lower heat insulating element (16a) close to the above can be obtained.

The heat insulating material (12) can be used not only for forming a flat surface on the outer wall surface of the structure to be insulated, but also as an auxiliary heat insulating material. For example, when a heat insulating material having a certain shape and size is arranged on the outer wall surface, the heat insulating material cannot cover the entire outer wall surface entirely due to restrictions on the shape and size, and the portion exposed to the outer wall surface (heat insulating material) Can be used to fill that part when it occurs.

FIG. 3 shows an example. In FIG. 3, the upper heat insulating element (16b) having a constant shape and size is arranged as described later. As a result of laying the upper heat insulating element (16b) without a gap, the upper heat insulating element (16b) is formed at the end of the outer wall surface. 16
In b), a portion (200a) that cannot be covered slightly remains. Therefore, a heat insulating material (12) is laminated on the portion (200a) to have the same thickness as the other portions, and a plate-shaped heat insulating element (17) is provided to adjust the appearance of the side surface. Thus, the heat insulating material (12) can be used as a heat insulating material that plays a role of an adjusting member in a broad sense, and its usefulness is extremely large.

The composite heat insulating material of the present invention is obtained by laminating an upper heat insulating element (16b) on a lower heat element (16a) made of a heat insulating material (12). In FIG. 1, the upper heat-insulating element (16) is formed by laminating four laminated units (15) in which a heat-insulating plate (13) and an inorganic fiber sheet (14) are laminated.

The heat insulating plate (13) is not particularly limited as long as it has heat insulating properties, that is, it is difficult to conduct heat on the high temperature side to the low temperature side. Such a heat insulating plate is, for example, a mica-based heat insulating plate. The mica heat insulating plate has a small thermal conductivity of 0.67 W / (mk) itself and a heat resistance temperature of about 7
Because it is as large as 00 ° C, it is suitable for a heat insulating plate. When using a mica-based heat insulating plate, its thickness is 200-3500 μm.
It is preferable that If it is less than 200 μm, the strength and the preservation at high temperatures may be reduced,
If it exceeds 3500 μm, the amount of heat (radiation) that is conducted in the plane direction (plane direction perpendicular to the thickness direction) and is released from the edges (side surfaces) of the mica insulating plate increases, and the heat insulating performance of the composite heat insulating material May be reduced.

Alternatively, the heat insulating plate (13) may be a metal plate having a high thermal reflectance on at least one of the front and back surfaces.
Such a metal plate can exhibit a heat insulating effect by reflecting radiant heat on a surface having a high thermal reflectance. Therefore, when using such a metal plate, it is necessary to arrange such that the surface having a high thermal reflectance is located on the high temperature side.

The metal plate used as the heat insulating plate (13) has an average roughness Ra of at least one of the front and back surfaces of 1.4.
It is preferable that the metal plate has a thermal emissivity of 0.1 μm or less and a thermal emissivity of 0.1 μm or less. Such a metal plate can be obtained by, for example, mirror-finishing at least one of the front and back surfaces of a stainless steel plate, for example, a SUS304 plate, a titanium plate, or a nickel plate. When the use temperature of the metal plate, that is, the temperature at which the metal plate is expected to be exposed is 450 ° C. or less, a flat plate made of aluminum may be used. The thickness of the metal plate is 50 μm or more
It is preferably 1500 μm. Metal plate thickness is 5
If the thickness is less than 0 μm, the shape may not be maintained due to heat, and if it exceeds 1500 μm, the heat is conducted in the plane direction (plane direction perpendicular to the thickness direction) and the amount of heat radiation from the edge of the metal plate. And the heat insulating performance of the composite heat insulating material may be reduced.

The heat insulating plate (13) has the same configuration as the heat insulating material (12), and the shape of the enclosure may be plate-like. In this case, it is necessary to make the porosity in the enclosure substantially zero to secure rigidity. For example, when the ceramic granular material is composed of the above-mentioned material containing silica and alumina, the packing density is set to 1500 to 2
Preferably, it is 500 kg / m ³ .

The inorganic fiber sheet (14) has fine voids formed of fibers made of an inorganic material. It is desirable that the fine voids exist so as to form a porosity of 10 to 75% in total. If it is 75% or more, the volume occupied by the voids becomes large and heat conduction occurs due to convection of air, and if it is less than 10%, it becomes too dense and heat conduction occurs between fibers. As a result, in any case, Insulation performance decreases.

The inorganic fiber sheet (14) has one or more fibers selected from the group consisting of fibers having heat resistance and / or low temperature resistance at the temperature at which it is used, for example, rock wool, glass fibers and ceramic fibers. Is obtained by forming a sheet having a fiber density in the range of 80 to 200 kg / m ³ using fibers having a fiber diameter of 0.8 to 8 μm. The sheet is
It may be a nonwoven fabric, a woven fabric, a felt, or a mesh, and may be a laminate of these.

In the present invention, the inorganic fiber sheet (1
The thickness of 4) is preferably 5 to 25 mm. When it is less than 5 mm, when a plurality of laminated units (15) composed of a heat insulating plate (13) and an inorganic fiber sheet (14) are laminated,
In the lower stacked unit where a larger load is applied,
Adjacent heat insulating plates (13) come into contact with each other without any intervening inorganic fiber sheet, and as a result, heat may be conducted at the contact portion, and the heat insulating performance may be reduced. If it exceeds 25 mm, convection of air is generated in the inorganic fiber sheet (14), which may deteriorate the heat insulating performance of the entire composite heat insulating material (10). The thickness referred to here is the thickness measured before laminating the inorganic fiber sheet (14). In an actual composite heat insulating material (10), the lower the inorganic fiber sheet is, the more the thickness is compressed. Tend to be smaller.

Insulation plate (13) and inorganic fiber sheet (14)
Are laminated to form one laminated unit (15).
The integration of the heat insulating plate (13) and the inorganic fiber sheet (14)
For example, heat-resistant (or low-temperature) adhesives, pins, screws,
Alternatively, it can be performed by using a U-shaped laminated body fixing bracket (for example, a clamp) or the like for sandwiching and fixing the laminated body, or by forming a projection on a metal layered element and forming the projection on an inorganic fiber sheet ( It can also be done by engaging 14). When the protrusions are formed on both sides of the heat insulating plate (13), the engagement with the inorganic fiber sheet of the adjacent unit becomes possible, and as a result, the laminated unit (1
5) It is possible to perform the integration between:

In the laminated unit, as shown in FIG. 4, the inorganic fiber sheet constituting the laminated unit is composed of a plurality of inorganic fiber sheet segments and void segments, and the inorganic fiber sheet segments are separated by the void segments in the plane direction (in the laminating direction). (A vertical plane direction). In the illustrated embodiment, the inorganic fiber sheet in the laminating unit (35) is such that the strip of inorganic fiber is formed of an inorganic fiber sheet segment (34a).
Each inorganic fiber sheet segment (34a)
Are separated in the plane direction by the gap segments (34b), and are arranged in parallel with each other. Otherwise, it is substantially the same as the composite heat insulating material shown in FIG.

Since the laminated unit (35) has a void segment (34b) having a higher heat transfer resistance, a better heat insulating effect than the laminated unit (15) shown in FIGS. 1 and 3 can be obtained. Is possible. Further, according to this aspect, the sheet segment (34) made of inorganic fibers is used.
Although a) acts as a kind of spacer, the sheet segment (34) made of inorganic fibers exhibits heat insulation performance by itself, similarly to the inorganic fiber sheet described above with reference to FIG. Therefore, by using this as a spacer, a better heat insulating effect can be obtained than when a solid element is used as a spacer.

In the present invention, in order to improve the heat insulating effect of the void segments, the thickness of the inorganic fiber sheet segment (34a) is set to HS, and the pitch when the inorganic fiber sheet segment (34a) is arranged in parallel. When the width of PS and the inorganic fiber sheet segment (34a) is WS, a value obtained by dividing PS by HS, that is, PS / HS
Is preferably 20 or more and 85 or less, and 40 or more and 6 or less.
More preferably, it is 0 or less. Further, it is preferable that a value obtained by dividing WS by HS, that is, WS / HS be 2 or more and 10 or less. When PS / HS is within the above range, the flow of air due to convection is suppressed in the void segment (34b), and as a result, a good heat insulating effect is obtained. P
If the S / HS is less than 20, the void segments become small and a sufficient heat insulating effect cannot be obtained. If the PS / HS exceeds 85, air layers having different specific gravities are generated in the vertical direction of the space due to heat. When the composite heat insulating material of the present invention is disposed on the outer wall surface of the high-temperature furnace due to convection, heat transfer to the upper part in the stacking direction is promoted, and the heat insulating effect may be reduced. On the other hand, if WS / HS is less than 2, the shape retention of the inorganic fiber sheet segment will be poor, and if it exceeds 10, the void segment will be so small that a sufficient heat insulating effect may not be obtained.

The sheet segment (34a) made of inorganic fibers may have the same structure as the inorganic fiber sheet (14) described above with reference to FIG.

FIG. 5 shows another embodiment of an inorganic fiber sheet having a sheet segment composed of inorganic fibers and a void segment, wherein the inorganic fiber sheet segments are separated in the plane direction by the void segments. FIG.
(A) is a plan view of the inorganic fiber sheet (44) as viewed from above. Here, a frame-shaped inorganic fiber sheet segment (44a) is employed to suppress the outflow of air in the gap segment (44b) when the lamination units are laminated. According to this structure, not only the convection of air can be suppressed, but also the inflow and outflow of air can be suppressed, so that a more excellent heat insulating effect can be obtained. As shown in FIG. 5B, a strip-shaped sheet segment (44a ′) made of inorganic fibers is disposed diagonally in a rectangular frame-shaped sheet segment (44a) formed of a sheet made of inorganic fibers.
The shape retention of the void segment (44b) is further improved by disposing the. In this case, the aforementioned P is represented in FIG.
(B), the distance between the diagonal inorganic fiber sheet segment (44a ') and the opposite corner may be considered. Also in this case, PS / HS is 20 or more and 8
It is preferably 5 or less, more preferably 40 or more and 60 or less. Further, WS / HS is preferably 2 or more and 10 or less.

When the inorganic fiber sheet has void segments as described above, a hard spacer may be inserted into the void segments. The hard spacer serves to prevent deformation of the laminated unit when a load is applied in the thickness direction of the laminated unit. FIG. 6 shows an embodiment of a laminated unit including a hard spacer. In FIG. 6, a plurality of strips (34a) of inorganic fiber sheets are arranged so as to be parallel to each other, and solid spherical hard spacers (50) are provided in gap segments (34b) between the strips (34a). Is inserted.

The hard spacer (50) is preferably formed of a hard ceramic material or metal. The shape of the hard spacer (50) is not only a solid sphere but also a shape as shown in FIGS. It is preferably a hollow spherical, cylindrical, tubular square or triangular prism, and its thickness (TU) is 1.
Preferably, it is 5 to 3 mm. If the thickness is less than 1.5 mm, when a load is applied at a high temperature (700 ° C. or more), the laminate unit (35) may be deformed and the shape retention of the laminated unit (35) may be deteriorated. If it exceeds 3 mm, heat conduction occurs in the plane direction of the hard spacer (the direction perpendicular to the thickness direction), so that the heat insulation performance of the laminated unit (35) is reduced.

The hard spacer has a thickness of the gap segment (ie, a thickness of the inorganic fiber sheet segment) of HS,
When the thickness and length of the hard spacer are HU and LU, HS / HU is 1 and LU / HS is 1 to 10
It is preferable to have dimensions such that The length (LU) of the hard spacer refers to a length in a direction parallel to the band when inserted into the gap segment.

The fact that HS / LU is 1 means that the hard spacer is inserted into the gap segment without forming a gap between the upper and lower heat insulating plates (13). If HS / LU is more than 10, the contact area between the hard spacer and the heat insulating plate (13) increases, and heat conduction occurs at the contact portion between the two, which may lower the heat insulating performance of the laminated unit. In order to minimize the contact area, the shape of the hard spacer is most preferably spherical (HU = LU). In addition, since the spherical hard spacer has a very small contact area with the heat insulating plate, unlike the other shapes, a solid spacer can be used.

The hard spacers are arranged at appropriate intervals to prevent deformation of the laminated unit due to a load. In general, laminated per laminate unit 1 m ² Unit 1
The hard spacers are preferably provided in each of the laminated units at a ratio of 9 to 170, more preferably 40 to 150 per m ² .

The hard spacer is fixed to the heat insulating plate (13) located on the upper side and / or lower side with a heat-resistant adhesive, a pin, a wire, or the like, and the laminated unit is arranged in any direction. It is preferable that the hard spacer does not fall off or move.

The composite material of the present invention in which the hard spacers are inserted enables, for example, a person to work on the composite heat insulating material and to place heavy piping parts and the like. Thereby, it becomes possible to broaden the applicable range of the composite heat insulating material of the present invention.

In the present invention, the laminated units (15) (3)
It is desirable that a plurality of layers 5) are stacked on the lower heat insulating element (16a) as an upper heat insulating element (16b).
The number of the laminated units (15) and (35) is preferably 4 or more, more preferably 4 to 40, and still more preferably 10 to 10.
25. If the number of layers is less than 4, for example, radiant heat from the outer wall surface of the high-temperature furnace cannot be sufficiently blocked, and a sufficient heat insulating effect may not be obtained. The higher the number of layers, the higher the heat insulating effect can be obtained, but the higher the cost. Therefore, the number of layers should be determined in consideration of the heat insulating effect and the cost.

In the embodiment shown in FIG. 1, the same laminated unit (15) is laminated, but in the present invention, the types of heat insulating plates are different from each other, or the types of inorganic fiber sheets are different. Alternatively, separate stacked units having different thicknesses and the like may be stacked.

It is preferable that the composite heat insulating material of the present invention described above further includes a heat conductive anisotropic sheet having higher heat conductivity in the plane direction than in the thickness direction. In the embodiment shown in FIG. 1, the heat conducting anisotropic sheet (11) is arranged so as to be in contact with the outer wall surface in order to make the temperature variation on the outer wall surface of the high temperature furnace uniform.

The thermally conductive anisotropic sheet (11) has a relatively higher thermal conductivity in the plane direction than in the thickness direction. In the present invention, the ratio of the thermal conductivity in the plane direction to the thermal conductivity in the thickness direction is preferably 4: 1 to 10: 1,
More preferably, it is 8: 1 to 10: 1. When the ratio of the thermal conductivity is smaller than 4: 1, the heat conduction in the plane direction becomes insufficient, and the temperature of the outer surface of the composite heat insulating material may fluctuate. The amount of heat radiation from the edge portion of the heat sink may increase, and the heat insulation performance may decrease. The heat conduction anisotropic sheet (11)
When the composite heat insulating material (10) is used for heat insulation of a high-temperature structure, it must have heat resistance. For example, the outer wall temperature of the structure is such that the working temperature inside the high-temperature structure is 800 ° C. It is desirable to be able to withstand even when exposed to.

A sheet preferably used as the heat conductive anisotropic sheet (11) is a graphite sheet. Graphite-based sheets generally have high thermal conductivity in the plane direction and can withstand use at about 600 ° C. In the present invention, the thermal conductivity particularly in the plane direction is 400 W / (m
K) or more and 1000 W / (m · K) or less, and the ratio of the thermal conductivity in the plane direction to the thermal conductivity in the thickness direction is 4: 1 to 1
It is preferable to use a graphite sheet having a ratio of 10: 1. If it is 400 W / (m · K) or less, heat conduction in the plane direction becomes insufficient, and the temperature variation on the outer surface of the composite heat insulating material becomes large, and 1000 W / (m).
If the temperature is more than K), heat conducted in the surface direction is likely to be radiated from the edge of the sheet, which may deteriorate the heat insulating performance of the composite heat insulating material, which is not preferable.

Since the graphite sheet has excellent thermal conductivity in the plane direction, the larger the thickness, the higher the thermal resistance for heat insulation. Further, the graphite-based sheet preferably maintains a tensile strength even at a high temperature, and preferably has a sufficient thickness so that cracks and breaks due to elongation due to thermal deformation do not occur, specifically 0.1 to 0.8 mm It is preferably about 0.3 to 0.8 mm. If the thickness of the graphite-based sheet is too large, the amount of heat radiation from the edge of the sheet increases, and the heat insulating performance of the composite heat insulating material may be reduced.

The graphite sheet can be produced, for example, by the method described in JP-A-3-75211. JP-A-3-75211 discloses polyoxadiazole, polybenzothiazole, polybenzobisthiazole, polybenzoxazole, polybenzobisoxazole, poly (pyromellitimide), poly (p-phenylene isophthalamide), (M-phenylenebenzimidazole), poly (phenylenebenzobisimidazole), polythiazole, and at least one polymer film selected from polyparaphenylenevinylene in an inert gas at a temperature of 2400 ° C. or more. A method is described in which graphite obtained by heat treatment is rolled to obtain a film-like graphite sheet.

The heat conduction anisotropic sheet has a low-temperature structure when the heat-insulating object is a low-temperature structure such that the heat-insulating object is in contact with the outer wall surface of the structure when the heat-insulating object is a high-temperature structure. Place it farthest from the object (the outer surface of the insulation). The heat conductive anisotropic sheet and the lower heat insulating element or the upper heat insulating element may be integrated by a heat-resistant adhesive, a pin, a screw, a bracket for fixing the U-shaped laminate described above, or the like. When the heat conductive anisotropic sheet is arranged on the outer wall surface of the high-temperature structure, the heat conductive anisotropy may be prevented from peeling off from the outer wall surface by a heat-resistant adhesive or the like.

When the outer wall surface of the high temperature insulation target structure has irregularities, it is necessary to lay a heat conductive anisotropic sheet so as to follow the outer wall surface so that no gap is formed between the outer wall surface. is there. For this purpose, the heat conductive anisotropic sheet may be cut as necessary, or two or more heat conductive anisotropic sheets may be used.

When the composite heat insulating material described above is actually used, the composite heat insulating material may be covered with a coating material as shown in FIG. 8 to form a coated composite heat insulating material. By covering the entire composite insulation (10) in advance, the insulation (1
2) Or even when dust is generated from the inorganic fiber sheet (14), the coating material effectively blocks dust, so that the coated composite heat insulating material is extremely low in dust generation. Since the covering type composite heat insulating material (60) can be handled as one heat insulating block, it is possible to shorten the construction work time at the time of construction and is excellent in workability.

As the coating material (610), an appropriate material may be selected according to the internal temperature of the structure to be adiabatically kept. For example, when the temperature in the furnace is 800 ° C.
When used for thermal insulation of high temperature furnaces, the coating material (610)
Is preferably a heat-resistant sheet, and specifically, an inorganic fiber sheet and a metal foil can be used. Examples of the sheet made of the inorganic fiber include a fiber sheet such as a woven fabric, a nonwoven fabric, and a felt made of known glass fiber or ceramic fiber. When a fiber sheet is used, its thickness is preferably 0.2 to 1.0 mm. If it is less than 0.2 mm, the strength may be low, and dust generation from the composite heat insulating material (60) may not be effectively suppressed. If it exceeds 1.0 mm, it will be difficult to perform bending or the like, resulting in poor shape retention and handling properties. For example, suturing may be difficult.

When coated with a metal foil, it is preferable that the metal foil has a high tensile strength at a high temperature and a small distortion and deformation due to heat. As such a metal foil, for example, there is a metal foil of stainless steel, titanium, or heat resistant steel such as SUS316L. If the temperature at which the coating is expected to be exposed is 450 ° C. or less, an aluminum foil can be used. The thickness of the metal foil is 0.04 to
It is preferably 0.25 mm. If the thickness is less than 0.04 mm, the strength may be reduced and may be broken during construction.
If it exceeds 25 mm, the shape-retaining property and the handling property are deteriorated, and the coating / sealing work may be difficult. The metal foil has substantially no gas permeability and can be used when it is desired to make the composite heat insulating material (10) an independent system from the outside.

The covering of the composite heat insulating material (10) is performed by the covering material (61).
This is performed by making a bag-like material in 0), putting the composite heat insulating material (10) in the bag-like material, and suturing the opening with a thread made of a heat-resistant adhesive or a heat-resistant fiber (joining part shown in FIG. Zu). Alternatively, use a composite insulation material (1
0), and the sheets are bonded with a heat-resistant adhesive or stitched with a thread made of heat-resistant fiber. The sheets may be joined by mechanical fastening means such as pins or rivets. Also, if the sheets are joined by, for example, a heat-resistant adhesive or welding, the joints become airtight.
Therefore, when a composite heat insulating material is covered with a metal foil to form a system independent from the outside, such a bonding method may be employed.

When the covering material (610) is a sheet having substantially no gas permeability and the joint thereof is airtight, the coated composite heat insulating material (60) can be used as a vacuum-resistant pipe. By means of a suitable connection means such as the above, the inside of the coating material (610) can be connected to a means capable of evacuating or vacuuming the inside, for example, a vacuum pump. Here, the vacuum resistant pipe means a pipe that does not deform even when the inside of the pipe is in a vacuum state. By reducing the pressure inside the coating material (610), the heat insulating effect is further improved. Preferred coating (610)
The internal pressure is 200 Torr or less, more preferably 1 Torr.
00 Torr or less, more preferably 0.001 Torr
It is in a vacuum state of 10 to 10 Torr.

As shown in FIG. 9, instead of or in addition to the above-mentioned means capable of reducing the pressure or creating a vacuum, the gas inside the coating material (710) is discharged and the coating material (7
10) Air supply / exhaust means (71
2) and the coated composite heat insulating material (70) may be connected by a suitable means (711) such as a vacuum-resistant pipe. If the air supply / exhaust means is used, the air inside the coating material (710) is forcibly exhausted, and then a gas having a low thermal conductivity, such as carbon dioxide, argon, and nitrogen, is forced into the coating material (710). To improve the heat insulating effect of the composite heat insulating material (70). If an inert gas is supplied, the oxidation can be prevented when the composite heat insulating material (10) is made of a metal such as iron which is easily oxidized at high temperature.

According to the apparatus shown in FIG. 9, for example,
After the heat treatment in the high-temperature furnace is completed, a gas such as air at room temperature or low temperature is sent from the supply / exhaust means (712) to the inside of the coating material (710) through an appropriate means (711) such as a vacuum-resistant pipe. Or by continuously supplying and exhausting such a gas, the outer wall of the furnace can be cooled quickly and forcibly. The heat on the outer wall surface of the furnace is absorbed by the gas sent into the coating material (710) via the coating material (710), and as a result, the temperature of the outer wall surface of the furnace is reduced. If the outer wall surface of the furnace is rapidly cooled, for example, there is an advantage that the time required for taking in and out the object to be processed in the high-temperature furnace is reduced, and the processing efficiency is improved.

The connection means is provided with a valve or the like so that communication with the connected device can be cut off, and the composite heat insulating material covered with the coating material can be formed as an independent system from the outside. Is also good.

In the composite heat insulating material of the present invention described above, the heat conductive anisotropic sheet is used adjacent to the outer wall surface of the high temperature structure to be insulated and kept warm. Even when the composite heat insulating material is covered with the covering material, the heat conductive anisotropic sheet is positioned so as to be adjacent to the outer wall surface of the high-temperature structure. The coating material is interposed in the coating.

Although the above description has been made mainly on the assumption that a material whose outer wall surface has a high temperature, such as a high-temperature furnace, is used as a heat insulating material for heat insulation, the composite heat insulating material of the present invention has a low temperature. It can also be used as a heat insulating material for heat insulating (cooling) the structure. In that case, the material constituting the composite heat insulating material, for example, inorganic fibers, must have low-temperature resistance according to the temperature at which it is used. The material must have low temperature resistance depending on the temperature used.

As described above, the composite heat insulating material of the present invention can be used at an operating temperature in the range of about -185 ° C. to 700 ° C. depending on the material used, and its application range is extremely wide. Can be used for heat insulation of a panel, a cathode ray tube and a ceramics substrate in a baking furnace, heat insulation of a liquid nitrogen storage container, or heat insulation of a container used for transporting frozen products at about 0 to -40 ° C.

[0089]

EXAMPLES The following materials were prepared as members constituting a composite heat insulating material: 1) Heat conductive anisotropic sheet Prepared according to the production method disclosed in Japanese Patent Application Laid-Open No. 3-75211 using perimide as a raw material. 0.6mm thick,
A graphite-based heat-resistant sheet having a thermal conductivity of 800 W / (mk) in the plane direction and a heat conductivity ratio of 8/1 in the plane direction and the thickness direction;

2-1) Heat Insulating Material A (Lower Heat Insulating Element) Enclosure: An opening having an area of 625 μm ² per unit is formed at a rate of 1000 / cm ² and has a thickness of 0.1 mm.
8 mm, made of a silica fiber sheet with a basis weight of 650 g / m ² (manufactured by Nichias Corporation; trade name: Siltex Cross 1000S), and the joining portion of the sheet was made of alumina fiber having a diameter of 0.8 mm (manufactured by Imae Industry Co., Ltd .; trade name: Balcon Yarn) Sewn and sealed at a pitch of 3 mm; ceramic granular material: 1 × 10 ^{-5 to} 6 × 1
0 ^-5 plurality of hollow portions having a volume of mm ³ is formed by formed so as to occupy 30 to 50% of the volume of one granulate 60
0 mesh hollow silica-based granules (pre-processed product of WDS board manufactured by Harima Ceramics Co., Ltd.); Porosity: 60% (filling density: 180 kg / m ³ ); Shape of heat insulating material: square pillar shape, width X depth x height 50mm x 50mm x 100mm, 25mm x
50mm x 50mm, 25mm x 50mm x 100mm are available.

2-1) Heat insulating material B (lower heat insulating element) Enclosure: 0.04 mm thick stainless steel (SUS30
4) A sheet made of a sheet, and the joining portion of the sheet is sealed at a pitch of 20 mm by spot welding. Ceramics-based granular material: Same as the above-mentioned heat insulating material A Porosity: Same as the above heat insulating material A Shape and size of the heat insulating material: Four It is prismatic and has a width x depth x height of 50mm x 50mm x 100mm.

3-1) Lamination unit A (upper heat insulating element) Heat insulating plate: Soft mica heat insulating plate having a thickness of 0.6 mm (manufactured by Okabe Mica Co., Ltd .; trade name: Damma 700L); Inorganic fiber sheet: 6 mm thick, density 160 kg / M ³ ceramic fiber felt (manufactured by IBIDEN Co., Ltd .; trade name: IBIWOOL # 1600); Insulation board and inorganic fiber sheet integrated: heat resistant adhesive (manufactured by Isolite Industries; trade name: Kao Stick); : A) Vertical x width is 455mm
X 605 mm rectangle and b) 455 x 300 mm rectangle.

3-2) Laminating unit B (upper heat insulating element) Heat insulating plate: Soft mica heat insulating plate having a thickness of 0.6 mm (manufactured by Okabe Mica Co., Ltd .; trade name Damma 700L); inorganic fiber sheet; thickness 6 mm, density 160 kg / M ³ of ceramic fiber felt (manufactured by IBIDEN Co .; trade name: IBIWOOL # 1600), and two strips each having a width × length of 30 mm × 225 mm are connected in series at a pitch of about 190 mm. A sphere having a diameter of 6 mm (manufactured by Mitsui Mining Materials Co., Ltd .; trade name: M-SLM) made of a ceramic material was placed in a gap segment between the belt-like bodies in a direction parallel to each other in the horizontal direction of the laminated uni-body.
9 pieces per laminating unit arranged at a pitch of ~ 150 mm; integration of heat insulating plate and inorganic fiber sheet: heat-resistant adhesive (manufactured by Isolite Industries; trade name: Kao Stick); planar shape of laminating unit: vertical x Horizontal is 455mm × 6
05mm rectangle.

(Example 1-1) In an air atmosphere at a temperature of 24 ° C., the entire outer wall surface of the heat treatment apparatus for an electronic component having a furnace temperature of 600 ° C., as shown in FIG. A conductive anisotropic sheet (11), a heat insulating material A (1) having dimensions of 50 mm × 50 mm × 100 mm
2) Laminating lower insulation elements (16a) with no gaps (108 per 455 mm x 605 mm rectangular surface); and 16 laminated units A (15) having a rectangular shape of 455 mm x 605 mm. , Heat-resistant adhesive between each unit (manufactured by Isolite Industry Co., Ltd .; trade name: Kao Stick)
A composite heat insulating material (10) having a working thickness (h) of about 200 mm, which is obtained by laminating upper heat insulating elements (16b) fixed in this order, is arranged. Heat conductive anisotropic sheet (1
A heat-resistant adhesive (manufactured by Isolite Industries; trade name: Kao Stick) was fixed between 1) and the outer wall surface (100), and between the members. Further, the same heat insulating plate as the heat insulating plate (13) of the laminated unit A was disposed as the outermost layer (S1) on the uppermost surface of the composite heat insulating material.

(Example 1-2) Example 1-1 was performed in the same manner as in Example 1-1 except that a heat insulating material B having a size of 50 mm × 50 mm × 100 mm was used instead of the heat insulating material A. The composite heat insulating material was arranged in the same heat treatment apparatus as that of the above.

(Comparative Example 1) On the outer wall surface of the same heat treatment apparatus as in Example 1-1, a sheet-like heat insulating material made of silica fiber having a thickness of 25 mm and having a density of 160 kg / m ³ (manufactured by IBIDEN Co .; trade name: IBIDEN blanket) # 1600) were laminated, and a heat insulating material was arranged so that the construction thickness became 200 mm. The space between the lowermost layer and the outer wall surface and between the layers were fixed with a heat-resistant adhesive (manufactured by Isolite Industry Co., Ltd .; trade name: Kao Stick).

The heat insulation performance of each of the heat insulating materials of Examples 1-1 and 1-2 and Comparative Example 1 was evaluated. Table 1 shows the results. Table 1
In the middle, the surface temperature of the heat insulating material was measured at nine points within a rectangle of 455 mm × 605 mm on the surface of the outermost layer (S1), and the average value was shown. The heat radiation heat flux was measured using a heat flux meter (EG type, manufactured by Kyoto Electronics Industry Co., Ltd.). The variation in the surface temperature is a value within a rectangular area of 455 mm × 605 mm. The dust generation level is 2
An airflow of 0 m / sec was blown, and the number of 1 μm dust particles contained in 1 m ³ was measured by a dust counter and evaluated.

[0098]

[Table 1]

From Table 1, it can be seen that the composite heat insulating material of the present invention has better heat insulating performance than the conventional heat insulating material. Also,
Due to the presence of the heat conductive anisotropic sheet, variations in surface temperature are reduced. The heat insulating performance of the composite heat insulating material including the lower heat insulating element and the upper heat insulating element used in Example 1 and not including the heat conductive anisotropic sheet was evaluated in the same manner as in Example 1. The variation in the surface temperature was ± 5 to ± 9 ° C., which also confirmed that the heat conductive anisotropic sheet contributed to the reduction in the variation in the surface temperature.

(Example 2) In an air atmosphere at a temperature of 24 ° C, the outer wall surface of a heat treatment apparatus for electronic parts having a furnace temperature of 600 ° C, and the entire outer wall surface having a projection, As shown in Fig. 3, ・ Thermal conduction anisotropic sheet (11) ・ Three kinds of heat insulating materials A (12) with different dimensions are spread without gaps to fit the projections of the outer wall surface (200), and the upper surface is flat A lower heat insulating element (16a) having a surface, and 16 laminated units A (15) each having a rectangular shape of 455 mm × 300 mm in a plane shape, and a heat-resistant adhesive (manufactured by Isolite Industries; product) A composite heat insulating material (10), which is formed by laminating upper heat insulating elements (16b) fixed by the name “chao stick” in this order, is arranged. The heat conductive anisotropic sheet (11) and the outer wall surface (200) and between the members were fixed with a heat resistant adhesive (manufactured by Isolite Industry Co., Ltd .; trade name: Kao Stick). Also,
On the uppermost surface of the composite heat insulating material, the same heat insulating plate as the heat insulating plate (13) of the laminated unit A was disposed as the outermost layer (S1). The thickness of the composite insulation material (10) differs between the part located on the convex part of the outer wall surface and the part located on the flat part of the outer wall surface.
The composite heat insulating material was arranged so that a minimum construction thickness (h1) of 200 mm was secured. In this case, the maximum construction thickness (h2) was 250 mm.

This composite heat insulating material could be efficiently constructed, and the construction could be completed in half the time required in Comparative Example 2 described later.

(Comparative Example 2) On the outer wall surface of the same heat treatment apparatus as in Example 2, a density of 16 mm
0 kg / m ³ sheet-shaped insulation (manufactured by IBIDEN)
IBIDEN blanket # 1600) was appropriately cut and arranged so as to be in close contact with the outer wall surface. As in the case of Example 2, the heat insulating material was arranged so as to ensure a minimum construction thickness (h1) of 200 mm. Further, the maximum construction thickness (h2) was 250 mm. Heat-resistant adhesive (manufactured by Isolite Industries; trade name: Kao Stick) between the bottom layer and the outer wall surface and between each layer
And fixed.

In the same manner as in Example 1, the heat insulation performance of Example 2 and Comparative Example 2 was measured. However, the measurement is 455 mm
The measurement was performed within a rectangular plane of × 300 mm. Table 2 shows the obtained results.

[0104]

[Table 2]

From Table 2, it can be seen that the heat insulating material of Example 2 has almost the same heat insulating performance as that of Example 1-1 at the portion where the construction thickness is 200 mm, and the heat insulating material of the present invention is used as the lower heat insulating element. As a result, it can be understood that an excellent heat insulating effect can be obtained regardless of the presence or absence of irregularities on the outer wall surface of the heat treatment apparatus. The variation in the surface temperature in Example 2 was slightly larger than that in Example 1, because the area to be measured was smaller than that in Example 1. The heat insulating material of Comparative Example 2 was inferior to that of Example 2 because the heat insulating material could not be sufficiently adhered to the irregularities on the outer wall surface.

Example 3 A composite heat insulating material was placed in the same heat treatment apparatus as in Example 1-1, except that the laminated unit B was used instead of the laminated unit A. Was. Then, a load was applied from the outer surface of the composite heat insulating material, and the compressibility and the heat insulating performance were measured. The compression ratio was determined from the formula of compression ratio = thickness of composite heat insulating material when a load was applied / thickness of composite heat insulating material when no load was applied.
The measurement of the heat insulation performance was performed in the same manner as in Example 1.
Table 3 shows the obtained results. In Table 3, the load of 0.118 kgf / cm ² corresponds to the load applied to the surface on which the person stands (about 800 cm ² in area) when the person stands on the composite heat insulating material.

[0107]

[Table 3]

As shown in Table 3, the composite heat insulating material having the hard spacers inserted therein is excellent in shape retention, and can maintain excellent heat insulating performance even when a large load is applied. When a load of 0.118 kgf / cm ² was applied to the composite heat insulating material of Example 1-1, the compression ratio was 0.875, and a decrease in heat insulating performance was recognized.

[0109]

In the composite heat insulating material of the present invention, the lower heat-insulating element having deformability ensures the close contact with the outer wall surface of the structure to be heat-insulated, and has a flat upper heat-insulating element thereon. Can be mounted. Further, the heat insulating material constituting the lower heat insulating element has a low dust generation level and is excellent in handleability. Therefore, the composite heat-insulating material of the present invention exhibits an excellent heat-insulating and heat-retaining effect and / or a heat-insulating and cold-holding effect even in a heat-insulating target structure having an uneven outer wall surface and unevenness, and efficiently applies the heat to the outer wall surface of the heat-insulating object. Can be constructed.

Further, when the composite heat insulating material of the present invention is combined with a heat conductive anisotropic sheet, a uniform heat insulating effect can be exhibited. Furthermore, by inserting a hard spacer into the composite heat insulating material of the present invention, it is possible to maintain excellent heat insulating performance even under a high load with excellent shape retention.

[Brief description of the drawings]

FIG. 1 is a sectional view of an example of a composite heat insulating material of the present invention.

FIGS. 2A and 2B are perspective views each showing an example of the shape of the heat insulating material of the present invention.

FIG. 3 is a sectional view of an example of the composite heat insulating material of the present invention.

FIG. 4 is a sectional view of an example of the composite heat insulating material of the present invention.

5 (a) and 5 (b) are plan views each showing an example of an inorganic fiber sheet used for the composite heat insulating material of the present invention.

FIG. 6 is a sectional view of an example of the composite heat insulating material of the present invention.

FIGS. 7A to 7D are perspective views each showing an example of a hard spacer.

FIG. 8 is a cross-sectional view of an example of the coated composite heat insulating material of the present invention.

FIG. 9 is a cross-sectional view of an example of the coated composite heat insulating material of the present invention.

[Explanation of symbols]

10 ... composite heat insulating material, 11 ... heat conduction anisotropic sheet, 1
2 ... Heat insulation material, 12a ... Enclosure, 12b ... Ceramics granular material, 13 ... Heat insulation plate, 14 ... Inorganic fiber sheet,
15 ... stacking unit, 16a ... lower heat insulating element, 16
b ... upper insulating element, 17 ... insulating plate, 100, 20
0: outer wall surface of high-temperature furnace, 34, 44 ... inorganic fiber sheet, 34a, 44a, 44a '... inorganic fiber sheet segment, 34b, 44b ... void segment, 35 ...
Laminated unit, 50 ... Hard spacer, 60, 70 ... Coated composite heat insulator, 610, 710 ... Coated material, 711 ...
Connection means, 712 ... supply / exhaust means.

Claims (20)

[Claims] 1. A heat insulating material comprising a porous ceramic-based granular material and / or a hollow ceramic-based granular material in an enclosure made of a metal sheet so that the porosity in the enclosure is 30 to 85%. 2. The heat insulating material according to claim 1, wherein the metal sheet has at least one surface having a high thermal reflectance, and the surface having a high thermal reflectance is located outside. 3. The heat insulating material according to claim 1, wherein the metal sheet is gas-impermeable, and the enclosure is filled with an inert gas. 4. The heat insulating material according to claim 1, wherein the metal sheet is gas-impermeable, and the inside of the enclosure is in a reduced pressure or vacuum state. 5. An enclosure made of an inorganic fiber sheet,
A heat insulating material comprising a porous ceramic-based granule and / or a hollow ceramic-based granule such that the porosity is 30 to 85%. 6. The inorganic fiber sheet has an opening area of 80 to 10000 μm ² per opening of 100 to 100 μm ^2.
The heat insulating material according to claim 5, wherein the heat insulating material is formed at a rate of 12,000 pieces / cm ² . 7. The porous ceramic-based granular material has a particle size of 100 to 100.
The granular material of 1000 mesh, wherein a plurality of small holes are formed so as to occupy 30 to 70% of the volume of one granular material together, according to any one of claims 1 to 6. Insulation. 8. The hollow ceramic-based granular material may be 100-1.
The granular material of 000 mesh, wherein one or a plurality of independent hollow portions is formed so as to occupy 20 to 60% of the volume of one granular material. Insulation as described. 9. A composite heat insulating material, wherein the heat insulating material according to claim 1 is a lower heat insulating element, and an upper heat insulating element is laminated thereon. 10. The composite heat insulating material according to claim 9, wherein the upper heat insulating element is formed by laminating a plurality of laminated units in which a heat insulating plate and an inorganic fiber sheet are laminated so that the heat insulating plate is on the lower side. 11. The composite heat insulating material according to claim 10, wherein the heat insulating plate is a mica heat insulating plate. 12. The composite heat insulating material according to claim 10, wherein four or more laminated units are laminated. 13. The inorganic fiber sheet of the laminated unit is composed of a plurality of inorganic fiber sheet segments and void segments, and each inorganic fiber sheet segment is separated from other inorganic fiber sheets by a void segment in a plane direction. The composite heat insulating material according to claim 10. 14. The composite heat insulating material according to claim 13, wherein a hard spacer is inserted into the gap segment. 15. Each of the inorganic fiber sheet segments is a strip, and these are arranged so as to be parallel to each other. The thickness of the strip is HS, the height of the hard spacer is HU, and the length is HU. 15. The composite heat insulating material according to claim 14, wherein HS / HU is 1 and HS / LU is 1 to 10, when expressed as LU. 16. The heat conductive anisotropic sheet having a heat conductivity relatively higher in a surface direction than in a thickness direction under the lower heat insulating element. A composite heat insulating material according to item 1. 17. The composite according to claim 9, wherein a heat conductive anisotropic sheet having a heat conductivity relatively higher in a plane direction than a thickness direction is disposed on an uppermost surface. Insulation. 18. The composite thermal insulation according to claim 16, wherein the ratio of the thermal conductivity in the plane direction to the thermal conductivity in the thickness direction of the thermally conductive anisotropic sheet is 4: 1 to 10: 1. Wood. 19. The heat conductive anisotropic sheet has a thermal conductivity in the plane direction of 400 W / (m · K) or more and 1000 W / (m · K).
K) The composite heat insulating material according to claim 16 or 17, wherein the composite heat insulating material is a graphite-based sheet having a ratio of conductivity in a plane direction and thermal conductivity in a thickness direction of 4 to 10: 1. 20. A coated composite heat insulating material, wherein the coating material covers the composite heat insulating material according to any one of claims 9 to 19.