JPH07115962B2 - Composite insulation - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a heat insulating material. More specifically, the present invention relates to a heat insulating material for wall surfaces of high temperature furnaces and high temperature ducts, and a heat insulating material used for joints of these heat insulating materials.

[0002]

2. Description of the Related Art Conventionally, a blanket-shaped heat insulating material in which alumina-based or alumina-silica-based ceramic fibers are entangled with each other has been known as a heat insulating material for wall surfaces of, for example, high-temperature furnaces and high-temperature ducts.

[0003]

However, as shown in FIG. 10, the above-mentioned alumina-based and alumina-silica-based ceramic fibers have an undesirably large amount of shrinkage at a temperature higher than 300 ° C., which results in heat insulation. There is a problem that a gap is created between the boundary of the materials or between the heat insulating material and the furnace wall, or a crack is generated in the heat insulating material, resulting in a decrease in heat insulating efficiency.

Further, in consideration of the amount of shrinkage during hot working, it is necessary to compress and compress by 10% or more to stack and fill, which requires a great deal of labor for construction.

[0005]

Therefore, in the composite heat insulating material of the present invention, a core material made of a heat-expandable heat insulating material is partially or entirely coated with a heat insulating material made of an alumina-based or alumina-silica-based ceramic fiber. It was done.

[0006]

When the composite heat insulating material is placed in a high temperature environment, the heat-expandable heat insulating material that constitutes the core material expands, and the heat insulating material composed of alumina-based or alumina-silica-based ceramic fibers contracts. Therefore, the shrinkage amount of the ceramic fiber is absorbed by the expansion amount of the heat-expandable heat insulating material, and the composite heat insulating material does not shrink overall. Therefore, a gap is not formed between the composite heat insulating materials or between the composite heat insulating material and the furnace wall, and a crack is not generated, and the desired heat insulating property is maintained.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a first embodiment of a composite heat insulating material according to the present invention, in which a blanket type composite heat insulating material 1 comprises a sheet-shaped core material 2 made of a heat-expandable heat insulating material and a coated blanket 3 made of a heat shrinkable heat insulating material. It is covered with. The sheet-shaped core material 2 and the covering blanket 3 are
They may be integrated with a commercially available adhesive for ceramic fibers, or sewn with a paper string or a plastic string. Paper and plastic cords are burnt out by heat, so they do not prevent thermal expansion.

As the heat-shrinkable heat insulating material, alumina-based ceramic fibers or alumina-silica-based ceramic fibers are used, and the coating blanket 3 is formed by intertwining these ceramic fibers.

The heat-expandable heat insulating material is composed of sepiolite mineral, heat-expandable unexpanded vermiculite, ceramic fibers, and an ethylene-based multi-component copolymer as an organic binder, and these are manufactured by a known paper-making method. Then, the sheet-shaped core material 2 is formed. The compounding ratio of each material is determined in consideration of the purpose of use and the state of use of the composite heat insulating material 1 so that an optimum size and shape can be secured not only during cold operation but also during hot operation. The expansion amount during hot working can be arbitrarily adjusted by increasing or decreasing the content of vermiculite. In addition to vermiculite, heat-expandable materials include phlogopite, perlite, expanded non-expanded graphite, expandable fluorinated mica, etc., and at least one kind of these materials may be contained. Good.

Incidentally, 4% by weight of sepiolite mineral, 54% by weight of unexpanded vermiculite, 30 ceramic fibers
3 rope-shaped samples with a diameter of 11.1 mm were prepared using a heat-expandable heat insulating material composed of a weight% of ethylene-based multi-component copolymer and a weight of 15 ° C under a surface pressure of 3.5 kgf / cm ^2. Table 1 shows the average expansion coefficient and the average expansion amount when heated to 750 ° C. with a temperature rise ratio of min.

[0011]

[Table 1] Temperature (℃) 100 200 300 330 350 400 450 500 Expansion rate (%) -3.32 -4.80 -5.91 0 22.16 33.99 42.86 49.51 Expansion amount (mm) -0.09 -0.13 -0.16 0 0.60 0.92 1.16 1.34 Temperature ( ℃) 600 650 700 750 Expansion rate (%) 60.95 65.76 68.35 65.02 Expansion amount (mm) 1.65 1.78 1.85 1.76

FIG. 2 shows a second embodiment of the composite heat insulating material. In the rope type composite heat insulating material 5, the core material 6 made of the heat expansive heat insulating material is coated with the heat shrinkable covering blanket 7. Is shaped like a rope. If necessary, the core material 6 and the covering blanket 7 may be integrated by an adhesive as in the first embodiment, or may be sewn with a paper string or a plastic string.

An application example of the composite heat insulating material will be described. Figures 3 and 4
Shows an example in which the blanket type composite heat insulating material 1 is applied to the furnace heat insulating wall, the heat insulating wall 11 in the furnace shell 10 is constructed by stacking the composite heat insulating material 1, and each composite heat insulating material 1 exposes the core material 2. The portion is arranged so as to face the furnace shell 10. Further, each composite heat insulating material 1 is hooked on an anchor bolt (not shown) provided on the furnace shell 10, or a plurality of binders, strings and the like are integrated to be fixed to the anchor bolt.

The composite heat insulating material 1 constructed as described above
When hot, the outer coating blanket 3 shrinks,
The core material 2 made of a heat-expandable heat insulating material expands and shows a general expansion tendency. As a result, the expansion of each composite heat insulating material 1 is restricted by the expansion pressure received from the adjacent composite heat insulating material 1, and the dimensions at the time of construction are maintained. Therefore, the composite heat insulating material 1
No gap is created between them or between the composite heat insulating material 1 and the furnace shell 10. Further, the composite heat insulating material 1 fixed to the anchor bolt is not subjected to an unreasonable force and does not crack. Therefore, the desired heat insulating property is continuously maintained.
Further, since the dimension in the cold state is maintained even when it is hot, there is no need to forcibly compress and stack the layers during construction.

FIG. 5 shows an example in which the blanket type composite heat insulating material 1 is applied to the joint filler of the furnace body.
Expansion of the composite heat insulating material 1 held between 2, 12 is restricted,
The joints are reliably sealed.

FIGS. 6, 7 and 8 show an example in which the rope-type composite heat insulating material 5 is applied to a brick-layer sealing material.
Are arranged along the vertical and horizontal joint edges of the front and rear bricks 13, 13 stacked in two rows, and prevent the high temperature atmosphere in the furnace from leaking through the gap between the bricks 13, 13. In the heat insulation construction of bricks, bricks are generally joined with mortar, but some bricks are empty without joining with mortar in order to secure a thermal expansion allowance. When the furnace pressure is high, there was a problem that the heat flow in the furnace leaked out from the joint part of the empty brick, causing heat loss,
By sealing the joint portion of the empty brick with the composite heat insulating material 5 as described above, it is possible to ensure the heat insulating property while ensuring the expansion allowance of the brick.

FIG. 9 shows a modified example of the blanket type composite heat insulating material 1 and an example in which the deformed composite heat insulating material is applied to the heat insulating inner wall material of the hot air duct. It is formed in a trapezoidal shape, and this core material 2a is covered with a covering blanket 3a except for the bottom surface portion. In this composite heat insulating material 1a, the exposed bottom surface of the core material 2a is connected to the hot air duct 14
A heat insulating layer 15 having a predetermined thickness is formed inside the hot air duct 14, and the inner cylindrical duct 16 for protecting the heat insulating layer is inserted inside the hot air duct 14.

In the above structure, when hot air is supplied into the inner cylinder duct 16, the composite heat insulating material 1a expands, and the expansion pressure fixes the inner cylinder duct 16. Therefore,
Conventionally, when forming a heat insulating layer with a heat insulating material of alumina-based or alumina-silica-based ceramic fiber, the inner cylinder duct is made slightly larger in anticipation of the shrinkage allowance of the heat insulating layer, and this is placed inside the heat insulating layer. Although it had to be forced in, the inner cylinder act 16 is properly held by the expansion pressure of the composite heat insulating material 1a when hot even if the inner cylinder duct 16 has the same diameter as the heat insulating layer or a slightly smaller diameter. , Construction becomes easy.

In the above description, as the cross-sectional form of the composite heat insulating material, a sheet-shaped heat-expandable heat insulating material covered with a U-shaped heat-shrinkable heat insulating material and a string-shaped heat expandable heat insulating material. However, the present invention is not limited to these two forms, and at least a part of the heat-expandable heat insulating material may be covered with the heat-shrinkable heat insulating material. Depending on the application, a sheet-shaped heat-expandable heat insulating material and an ordinary heat-insulating material may be joined together and coated with a heat-shrinkable heat insulating material in a U-shape or around the entire circumference. further,
Although FIG. 3 and FIG. 9 show examples of combined use of composite heat insulating materials, it goes without saying that composite heat insulating materials and ordinary heat insulating materials can be applied alternately or in any other combination arrangement.

[0020]

As is apparent from the above description, the composite heat insulating material according to the present invention is a combination of a heat-expandable heat insulating material and a heat-shrinkable heat insulating material, and the latter heat shrinking amount is complemented by the former heat expanding amount. Therefore, it does not shrink when hot. In addition, the heat insulating wall formed by stacking the composite heat insulating materials is held in the cold shape by the expansion pressure received from the adjacent heat insulating material when hot. Therefore, the space between the heat insulating material and the heat insulating material or between the heat insulating material and the furnace shell is surely sealed, and the necessary heat insulating property is maintained.

[Brief description of drawings]

FIG. 1 is a perspective view of a blanket type composite heat insulating material according to a first embodiment.

FIG. 2 is a perspective view of a rope-type composite heat insulating material according to a second embodiment.

FIG. 3 is a cross-sectional view of a heat insulating wall made of a blanket type composite heat insulating material.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a cross-sectional view in which a blanket type composite heat insulating material is applied to a joint filler.

FIG. 6 is a plan view of a brick layer in which a rope-type composite heat insulating material is used as a sealing material.

FIG. 7 is a front view of a brick layer in which a rope-type composite heat insulating material is used as a sealing material.

8 is a sectional view taken along line VIII-VIII of FIG.

FIG. 9 is a cross-sectional view in which a blanket type composite heat insulating material is applied to a heat insulating wall of a hot air duct.

FIG. 10 is a diagram showing shrinkage characteristics of alumina-based and alumina-silica-based ceramic fibers with respect to temperature.

[Explanation of symbols]

1,5 ... Blanket type composite heat insulating material, 2,6 ... Core material,
3, 7 ... Coated blanket.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliography Flat 3-92733 (JP, U) Live 56-123998 (JP, U) Live 58-19193 (JP, U)

Claims (1)

[Claims] 1. A composite heat insulating material, wherein a core material made of a heat-expandable heat insulating material is partially or entirely coated with a heat insulating material made of alumina-based or alumina-silica-based ceramic fibers.