JP2015048405A - Endothermic material using inorganic porous body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new endothermic material.SOLUTION: An endothermic material 1 made of a water-absorbed inorganic porous molded body 11 is used as an endothermic material used for placed or equipment requiring fire resistance such as an atomic power plant. The circumference of a case filled with a cable lying at the step of a cable rack with the endothermic material (with a thickness of 25 mm). Further, the circumference thereof is surrounded with a laminated adiabatic material. The laminated adiabatic material is obtained by laminating the adiabatic material 1 layer (20 mm) and the second adiabatic material 3 layer (25 mm×3) from the inside having the cable, and the whole of the outside is covered with a silica cloth.

Description

  The present invention relates to an endothermic material using an inorganic porous material and a method for producing the same.

There are facilities that require heat resistance or fire resistance to cables in facilities due to disasters such as nuclear power plants, thermal power plants, and other fires.
Normally, heat resistance or fire resistance is realized by coating these cables with heat absorbing materials. However, conventional heat absorbing materials are made by adding water to a polymer absorber when heated. Or endothermic using water molecules (crystal water) contained in the hydrate (Patent Documents 1 and 2).
However, the conventional heat-absorbing material has been problematic in that it is difficult to replace the cable covering because it is bulky and heavy, or after the cable is laid, the space for covering the cable is narrow.

Since the polymer absorber is not a molded body, the endothermic material made of the polymer absorber has no self-supporting property and no retention. Therefore, although it can respond to the construction which is wound around or pasted on the construction site, the construction which is self-supporting on the wall surface or the construction in the space is very difficult. Furthermore, such an endothermic material has to be replaced, and the cost and labor have become enormous.
The endothermic material using hydrate has a problem that the cable breaks before the hydrate is decomposed because the decomposition temperature of the hydrate is higher than the heat resistance temperature of the cable.

Therefore, there has been a demand for an endothermic material that does not require replacement, can be installed in a narrow space, is lightweight, and absorbs heat efficiently.
On the other hand, zonotlite calcium silicate molded bodies are known as heat insulating materials (Patent Documents 1 and 2).

JP 59-102856 A JP-A-61-186256

  An object of the present invention is to provide a novel endothermic material.

  As a result of diligent research, the inventors of the present invention have added water with a high heat of vaporization to the inorganic porous molded body, which is excellent as an endothermic material because of its strong endothermic action and high shape retention, and further, water has evaporated. After that, it discovered that it functions as a heat insulating material, and completed this invention.

According to the present invention, the following endothermic material and method for producing the same are provided.
1. An endothermic material comprising an inorganic porous molded body that has absorbed water.
2. 2. The endothermic material according to 1, wherein the inorganic porous molded body is a molded body containing one or more inorganic powders selected from calcium silicate, silica, alumina, vermiculite, mica, cement, and pearlite.
3. The endothermic material according to 1 or 2, wherein the inorganic porous molded body is a molded body containing one or more inorganic fibers selected from glass fibers, rock wool, ceramic fibers, and biosoluble inorganic fibers.
4). The endothermic material according to any one of 1 to ³ , wherein the inorganic porous molded body has a density of 40 to 400 kg / m ³ .
5. The endothermic material according to any one of 1 to 4, wherein the absorbed water includes one or more additives selected from an antifreeze solution, a preservative, and a pH adjuster.
6). The endothermic material according to any one of 1 to 5, which is wrapped with a packing material.
7). The endothermic material according to 6, wherein the packing material is a laminate of a metal foil and a resin.
8). 8. The endothermic material according to 7, wherein the metal foil is an aluminum foil, aluminum foil, copper foil, tin foil, nickel foil, stainless steel foil, lead foil, tin-lead alloy foil, bronze foil, silver foil, iridium foil, or phosphor bronze.
9. The endothermic material according to 7 or 8, wherein the resin is a thermoplastic resin.
10. The endothermic material according to any one of 6 to 9, wherein the packing material is damaged at 70 ° C to 130 ° C.
11. A method for producing an endothermic material, wherein water is absorbed in an inorganic porous molded body and wrapped with a packing material.

  According to the present invention, a novel endothermic material can be provided.

It is a figure which shows the endothermic material concerning one Embodiment of this invention. It is a figure which shows the endothermic material concerning other embodiment of this invention. 3 is a schematic cross-sectional view showing a fireproof structure manufactured in Example 2. FIG. 3 is a schematic longitudinal sectional view showing a fireproof structure manufactured in Example 2. FIG. 6 is a schematic longitudinal sectional view showing a fireproof structure manufactured in Example 3. FIG.

The endothermic material of the present invention includes an inorganic porous molded body in which water is absorbed (impregnated).
The molded body to be used is a self-standing molded body such as a boat, for example.

  Examples of the inorganic porous molded body include a molded body obtained by mixing one or more inorganic powders such as calcium silicate, silica, alumina, vermiculite, mica, pearlite, and cement.

Moreover, as an example of an inorganic porous molded object, the inorganic fiber molded object which mixed and processed 1 type or 2 types or more of inorganic fibers, such as glass fiber, rock wool, a ceramic fiber, and a biosoluble inorganic fiber, is mentioned.
The ceramic fiber is a fiber mainly composed of silica and alumina (silica: alumina = 40: 60 to 0: 100), and specifically, silica / alumina fiber, mullite fiber, and alumina fiber can be used.

Moreover, in view of the health safety of the worker, biosoluble fibers having high heat resistance can be used.
The biosoluble fiber is generally composed of silica and / or alumina as a main component, alkali metal oxide (Na ₂ O, K ₂ O, etc.), alkaline earth metal oxide (CaO, etc.), magnesia, zirconia, titania. 1 or more selected from. Other oxides can also be included.

For example, the following compositions can be exemplified.
The total of SiO ₂ , ZrO ₂ , Al ₂ O ₃ and TiO ₂ 50 wt% to 82 wt%
Total of alkali metal oxides and alkaline earth metal oxides 18% to 50% by weight

More specifically, the following composition 1 or composition 2 can be illustrated.
[Composition 1]
SiO ₂ 70~82 weight%
CaO 1-9% by weight
MgO 10-29% by weight
Less than 3% by weight of Al ₂ O ₃ [Composition 2]
SiO ₂ 70~82 weight%
CaO 10-29% by weight
MgO 1 wt% or less Al than ₂ O ₃ 3% by weight

As the inorganic porous molded body, a calcium silicate molded body and a ceramic fiber molded body are particularly preferable, and a calcium silicate molded body is more preferable. Among the kinds of calcium silicate, xonotlite _{6CaO · 6SiO 2 · H 2 O} , tobermorite _{5CaO · 6SiO 2 · 5H 2 O} , is wollastonite CaSiO ₃ Preferably, particularly preferred is a high heat resistance xonotlite. Since the calcium silicate molded body is light and has small pores, water is easily retained uniformly.

  In addition to the above, the inorganic porous molded body can contain an inorganic binder, particles, and the like.

  As a manufacturing method of a calcium silicate molded object, it can manufacture by the method of patent document 1,2. Specifically, silica stone, slaked lime or the like is dispersed in water to form a slurry, which is hydrothermally synthesized in a stirring pressure vessel to synthesize secondary particles of calcium silicate hydrate. This slurry can be produced by wet suction dehydration molding.

  Moreover, an inorganic fiber molded object can be manufactured by shape | molding the inorganic fiber manufactured by the rotor method, the blowing method, the melt spinning method, etc. using a binder etc. Specifically, various fibers, binders, and the like are dispersed in water to form a slurry, and this slurry can be manufactured by wet suction dehydration molding.

The density of the inorganic porous molded body is 40 to 400 kg / m ³ for the purpose of being lightweight, containing a large amount of water, and having a strength capable of maintaining good shape retention even after holding water. A degree is preferred. More preferably, it is 80-300 kg / m < ³ >, More preferably, it is 100-200 kg / m < ³ >.

  The shaped body can contain water in a weight of 100 to 400% of the weight of the shaped body. The shaped body preferably contains 130-300%, more preferably 150-250% water.

The water absorbed by the inorganic porous molded body can contain various additives such as antifreeze, preservative, and pH adjuster.
Since water may expand in volume and damage the packing material when frozen, it preferably contains an antifreeze. Also, depending on the environment, the pH of impregnated water may change due to trace elution components from the inorganic porous molded body due to long-term storage, which may alter the inorganic porous molded body, the packing material, and even the water itself. It is preferable that a pH adjuster is contained. The thing to include in water is not restricted to this, It can add as needed.

The inorganic porous molded body containing water is preferably packed with a packing material (package).
The sealing property of the packing material may be a level that prevents evaporation of water from the water-containing molded body in a normal state. The packing material is damaged by heating, and water is evaporated. At that time, the heat is absorbed by heat of vaporization.
The breakage temperature due to heating is preferably the boiling point of water (below). If the boiling point is exceeded, the packing material may explode, and if it is much lower than the boiling point of water, the packing material will be damaged at an early stage, and the water will evaporate, thereby effectively obtaining an endothermic effect. Can not. Therefore, the breakage temperature of the packing material is more preferably 70 ° C to 130 ° C. More preferably, it is 80 degreeC-120 degreeC, More preferably, it is 90 degreeC-110 degreeC. If it breaks at such a temperature, water evaporates along with the breakage, and an endothermic effect can be exhibited.

  As a packing material for packing the water-containing inorganic porous molded body, a metal or a resin can be used. A laminate obtained by laminating a metal and a resin is preferable because of high heat resistance and strength. The laminate of metal and resin is preferably a laminate of three or more layers including a resin layer, a metal layer, and a resin sealant layer.

  Examples of the metal used include aluminum foil, copper foil, tin foil, nickel foil, stainless steel foil, lead foil, tin-lead alloy foil, bronze foil, silver foil, iridium foil, and phosphor bronze. In particular, aluminum foil, copper foil, and nickel foil are preferable, and aluminum foil is more preferable.

  As the resin, a thermosetting resin or a thermoplastic resin can be used. Examples thereof include polyethylene, polypropylene, polystyrene, nylon, acrylic, epoxy resin, polyurethane, polyether ether ketone, polyethylene terephthalate, polyphenyl sulfide, fluorine, polycarbonate, and aramid. Of these, a resin that is broken at a temperature of about 100 ° C. is preferable.

  Although the thickness of a packing material is not specifically limited, For example, they are 5 micrometers-200 micrometers. In the case of the above laminate, the metal foil can be 3 μm to 12 μm, and the resin layer can be 2 μm to 60 μm. Thereby, while exhibiting the heat resistance of a metal foil, fire resistance, and low water vapor permeability, sealing property can be improved with resin.

  The packing material may be partially provided with a mechanism and a structure for releasing the pressure in the package generated by heating. For example, a part that lowers the adhesive strength of the film fusion part is provided in a part of the packing material by changing the film type and structure. Alternatively, a hole is made in a part of the film, and a film thinner than the package film is pasted or melt-formed. Thereby, when the pressure in the package rises, the packing material does not swell more than necessary, and the original dimensions can be maintained to some extent.

  The endothermic material of the present invention can be produced by absorbing water in a porous body and wrapping it with a packing material containing one or two of metals and / or resins.

  FIG. 1 shows a cross-sectional view of an example of the endothermic material of the present invention. The endothermic material 1 has a packing material 13 for packing the inorganic porous molded body 11 containing water. In the endothermic material 1 of FIG. 1, the packing material is fused at the fusion part 15. The size of the endothermic material is not limited and can be appropriately determined depending on the application.

  The endothermic material as shown in FIG. 1 may be used as it is, or a plurality of the endothermic materials shown in FIG. 1 may be connected as shown in FIG. The two or more connected endothermic materials shown in FIG. 2 are convenient because they can be folded and rolled when being carried in a small place. Moreover, it can arrange | position according to the shape of a target object.

After the endothermic material of the present invention functions as an endothermic material, the inorganic porous molded body from which water has disappeared also functions as an excellent heat insulating material.
The endothermic material of the present invention can be used alone as a heat insulating material, but may be combined with other heat insulating materials. By combining them, a more effective heat insulation structure can be constructed, and strong heat insulation and fire resistance can be exhibited.

Example 1
Zonotried calcium silicate molded product (Keical Ace Super Silica, Nippon Keikal Co., Ltd.) (density 120 kg / m ³ , thermal conductivity at 500 ° C. of 0.114 W / (m · K) or less) (length 600 mm × width 300 mm × A thickness of 50 mm) was used.
This molded body was cut into a size suitable for use in the examples described later, and 200% by weight of water twice as much as the molded body was included.
The resulting water-containing molding is composed of a laminate of nylon (15 μm), aluminum foil (7 μm), and linear low-density polyethylene (LLDPE) (40 μm) from the surface. Got.

Example 2
(1) Assembly of fireproof structure Using the endothermic material (thickness 50 mm) manufactured in Example 1 and the following first and second heat insulating materials, the fireproof structure shown in FIGS. Carried out.
First heat insulating material: Microporous fumed silica molded body (Roslim board GH, NICHIAS Corporation) (800 ° C. thermal conductivity 0.04 W / (m · K))
Second heat insulating material: biosoluble fiber blanket (biosoluble fiber composition: about 73 mass% SiO ₂ content, about 25 mass% CaO content, about 0.3 mass% MgO content, Al ₂ O ₃ Content approx. 2% by mass) (Shrinkage rate at 1000 ° C. for 24 hours 0.6%)

The procedure for assembling the fireproof structure 400 shown in FIG. 3 is shown below.
The step 105 of the cable rack was fixed to a frame attached to the cable rack, and the cable rack 103 was assembled. A case (not shown) containing cables was placed on the stage 105 of the cable rack.
The angle of the heat insulating material casing was assembled, the inner metal panel was attached, and a rectangular parallelepiped heat insulating material casing (not shown) in which only the lower surface was released was assembled.
A cable rack 103 was installed in the vertical furnace 500, and a heat insulating material casing (not shown) was attached around the cable rack 103.

An endothermic material 401 was attached to a metal panel for the inside of the heat insulating material box.
One or three layers of the first heat insulating material 405 were attached to the heat absorbing material 401.
The second heat insulating material 403 was wound around the first heat insulating material 405.
A metal panel (not shown) for the outside of the heat insulating material casing was attached to the outside of the second heat insulating material 403, and the fireproof structure 400 was assembled.

(2) Evaluation of fireproof structure FIG. 4 is a schematic longitudinal cross-sectional view of a fireproof structure, and is a figure which shows the installation position of a thermocouple.
The thermocouple includes an outer surface of the second heat insulating material (551, 555, and 559 in FIG. 4), a space between the heat absorbing material and the first heat insulating material (555, 557, and 561 in FIG. 4), and an inner surface of the heat absorbing material. (In FIG. 4, 554, 558 and 562).
In the vertical furnace 500, heating was performed for 3 hours with an ISO standard fire resistance curve by a burner, and then allowed to cool for 2 hours. Table 1 shows the measured temperatures (° C.) after 1, 2, 3 and 5 hours at the respective thermocouple installation positions.

Example 3
(1) Assembly of fireproof structure FIG. 5 is a schematic longitudinal sectional view of the fireproof structure 600 assembled in the third embodiment.
In Example 3, the cable rack 103 suspended from the ceiling was used. The cable rack 103 has a plurality of steps, and a case containing the cables 101 is placed on the steps.
The heat-absorbing material 601 (thickness 25 mm) manufactured in Example 1 surrounded the periphery of the case containing the cable 101 in the step of the cable rack. Further, the periphery was surrounded by a laminated heat insulating material 603. The laminated heat insulating material 603 is formed by laminating the following third heat insulating material 1 layer (20 mm) and the following second heat insulating material 3 layers (25 mm × 3) from the inner side where the cable is present, and the entire outside is made of silica cloth. Wrapped.
・ Third heat insulating material: Aerogel / Inorganic fiber composite (Pyrogel, Aspen Co., Ltd.)
Second heat insulating material: biosoluble fiber blanket (biosoluble fiber composition: about 73 mass% SiO ₂ content, about 25 mass% CaO content, about 0.3 mass% MgO content, Al ₂ O ₃ Content about 2% by mass)

(2) Evaluation of fireproof structure A thermocouple was installed near the cable 101 outside the laminated heat insulating material 603, between the blanket layers of the laminated heat insulating material 603, between the laminated heat insulating material 603 and the heat absorbing material 601.
In the same manner as in Example 2, the mixture was heated on the ISO standard fire resistance curve for 3 hours and then allowed to cool for 2 hours. Table 2 shows the measured temperatures (° C.) after 1, 2, 3 and 5 hours at the respective thermocouple installation positions.

  The endothermic material of the present invention can be used as an endothermic material used in a place or facility where fire resistance is required, such as a nuclear power plant.

DESCRIPTION OF SYMBOLS 1, 2 Endothermic material 11 Hydrous inorganic porous molded body 13 Packing material 15 Fusion part 101 Cable 103 Cable rack 105 Rack stage 400,600 Fireproof structure 401,601 Endothermic material 403 First heat insulating material 405 Second heat insulating material 500 Vertical furnace 500
551,553,554,555,557,558,559,561,562 Installation position of thermocouple 603 Laminated heat insulating material

Claims (11)

  An endothermic material comprising an inorganic porous molded body that has absorbed water.   The endothermic structure according to claim 1, wherein the inorganic porous molded body is a molded body containing one or more inorganic powders selected from calcium silicate, silica, alumina, vermiculite, mica, cement, and pearlite. Wood.   The heat absorption according to claim 1 or 2, wherein the inorganic porous molded body is a molded body including one or more inorganic fibers selected from glass fibers, rock wool, ceramic fibers, and biosoluble inorganic fibers. Wood. The endothermic material according to any one of claims 1 to ³ , wherein the inorganic porous molded body has a density of 40 to 400 kg / m ³ .   The endothermic material according to any one of claims 1 to 4, wherein the water contains one or more additives selected from an antifreeze solution, a preservative, and a pH adjuster.   The endothermic material according to any one of claims 1 to 5, which is wrapped with a packing material.   The heat absorbing material according to claim 6, wherein the packing material is a laminate of a metal foil and a resin.   The heat absorbing material according to claim 7, wherein the metal foil is an aluminum foil, an aluminum foil, a copper foil, a tin foil, a nickel foil, a stainless steel foil, a lead foil, a tin-lead alloy foil, a bronze foil, a silver foil, an iridium foil, or phosphor bronze. .   The heat absorbing material according to claim 7 or 8, wherein the resin is a thermoplastic resin.   The endothermic material according to any one of claims 6 to 9, wherein the packing material is damaged at 70 ° C to 130 ° C.   A method for producing an endothermic material, wherein water is absorbed in an inorganic porous molded body and wrapped with a packing material.

Images