JP2000320980A - Insulating fireproof wall structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulating fireproof wall structure short in a working time and long in the durable period of time of a fiber block, and capable of finishing a re-application work easily in a short period of time. SOLUTION: An insulating light-weight castable 15 containing ceramic fiber and consisting of alumina-base or mullite-base aggregate, a fireproof material and binder, is applied on the wall surface of an industrial furnace. A block type or felt type ceramic fiber 13 is applied on the castable, and, further, anchor hooks 14 made of a metal or ceramic are buried in the ceramic fiber 13 for fixing the block type or felt type ceramic fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulated fire-resistant wall used for an industrial furnace such as a heating furnace or a steelmaking vessel lid such as a tundish or a molten steel pot.

[0002]

2. Description of the Related Art In recent years, linings made of ceramic fibers have become commonplace in place of plastic refractories and castable refractories for heating furnace walls and steel vessel lids as an energy saving measure. FIG. 1 shows an example in which a block-shaped ceramic fiber 3 is installed on an existing refractory 1 via an adhesive bander 2 and a ceramic anchor 4 is embedded.

[0003] Ceramic fiber is used in the form of a block in advance for ease of construction, a hole is drilled in the wall of a plastic refractory, a ceramic anchor is embedded, and an adhesive binder is applied to the wall and the block. While fixed lining.

Further, a method of applying a lightweight castable or a mixture of a ceramic fiber and a binder to the surface of a refractory wall by using a spraying apparatus has been studied on a trial basis.

[0005]

However, a ceramic fiber block (thickness: about 30 to 50 m) is provided on the refractory wall.
In order to apply m), the lining cannot be done unless the moisture of the refractory (plastic refractory, castable refractory) is completely removed. Dilutes the adhesive binder and causes the blocks to fall off.

Therefore, in order to line the fiber block, it is necessary to line the fiber block after the moisture in the refractory has been completely removed.

[0007] Sprays adhere to the walls (plastic castable refractories) of heating furnaces and steel-making pot lids that have been used for several years, and are melted into glass by the wetting of fuel components and high heat flame or scale components. In many cases, when lining a ceramic fiber block, the lining cannot be performed unless the splash and the molten layer are completely removed with a pick or the like in order to make the adhesive binder work effectively. The molten layer is
There is a problem that a considerable amount of time and labor is required for the removal operation because the thickness is several tens mm when the thickness is from several mm.

Further, even when the fiber block is already lined, even when the block is dropped or melted at a high temperature and a high flow rate, the binder or the fiber block remaining on the wall surface is repaired. It is difficult to carry out the repair work after completely removing it, and if this work is not performed, it will not only promote the falling off, but also cause the healthy other parts to fall off.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a short construction time, a long service life of a fiber block, a short reworking work, and a simple construction. It is to provide a certain insulated fire wall structure.

[0010]

In order to solve the above-mentioned problems, an adiabatic refractory structure according to the present invention comprises an industrial furnace wall, a ceramic fiber-containing lightweight castable formed on this wall, and a block-shaped or And a felt-like insulating ceramic fiber. Here, when a lightweight castable is formed, it is preferable to bury the tip of a metal or ceramic anchor hook for fixing the fiber block.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The lightweight castable for forming the heat-insulated refractory structure of the present invention is an insulated lightweight castable containing ceramic fibers. More specifically,
9-301779, calcined gypsum 5 to 50 wt%, preferably 8 to 25 wt% Refractory raw material (one or more of alumina, alumina-silica and chamotte, maximum particle size 7mm or less, 15
９４94.5 wt%), ceramic fibers (alumina, alumina-silica, mullite or chromium oxide-containing, crystalline or amorphous), and the content is determined by volume stability or high heat insulation. 1-50 w
It is an addition amount of t%.

And a porous material (one or more of alumina hollow aggregate, chamotte, perlite, perlite, vermiculite and artificial lightweight aggregate, bulk specific gravity 0.03
1.5 to 1.5, a maximum particle size of 7 mm or less, an addition amount of 10 to 50 wt%), and one or more of clay, bentonite and ultrafine silica powder in an amount of 0.5 to 15
wt%.

The reason why the lightweight castable according to the present invention contains ceramic fibers is as follows.

Generally, a lightweight castable is a mixture of a lightweight aggregate (pearlite, artificial lightweight aggregate, hollow alumina) and a binder (alumina cement). But,
In the case of the same lightweight castable, the use of aggregates lacking heat resistance, as typified by perlite and artificial lightweight aggregates, is indispensable in order to reduce the weight, and added as a binder to develop strength The large amount of alumina cement to be added causes a further decrease in heat resistance and a significant decrease in strength in an intermediate temperature range (400 to 800 ° C.).

Therefore, when such a lightweight castable is used for the heat-insulating and fire-resistant structure of the present invention, a stable structure cannot be obtained from the viewpoint of heat resistance, and the strength cannot be obtained even when an anchor or the like is embedded. It is impossible to fix and hold, and a problem occurs that the anchor comes off during use.

In the case of a heat-insulated lightweight castable to which an alumina hollow aggregate is added, the heat resistance of the aggregate itself is superior to the above-mentioned lightweight castable, but the effect of a large amount of alumina cement added for strength development is also considered. It cannot be covered, and the thermal conductivity itself increases with an increase in the alumina content, resulting in a structure that is no different from the construction of a general refractory castable. Thus, in the present invention, the lightweight castable contains ceramic fibers.

The thickness of the heat-insulated lightweight castable is 20
It is preferable that it is not less than 100 mm and not more than mm. 20m
If it is less than m, not only is it difficult to bury the anchor when the anchor is buried, but it also has a significant effect on the heat resistance and volume stability of the structure due to the reaction with the scale attached to the wall. is there. If the construction thickness exceeds 100 mm, peeling from the wall surface is likely to occur due to the influence of the castable weight.

[0018] The application method is trowel coating, spraying, and patching. However, in consideration of the adhesion to the wall surface and the working time, the application by the spraying method is more suitable.

The heat-insulating lightweight castable having the above structure can be adhered to a vitrified molten wall surface, and can secure volume stability and high heat insulation.

In the present invention, a ceramic fiber is further applied on the above-mentioned lightweight castable to further improve the heat insulating effect. As the ceramic fiber, a block or felt-like material is used, but from the viewpoint of workability, it is convenient to construct a block product.

The ceramic fiber used is appropriately set according to the operating temperature and conditions. Generally, a crystalline or amorphous material containing alumina, mullite or chromium oxide is used, but is not particularly limited.

The construction thickness is preferably about 20 to 50 mm. If it is too thin, the boundary temperature between the refractory wall and the first lightweight castable will increase, and the strength of the adhesive binder and better heat insulating properties will not be obtained. If the thickness is too large, the effect on the cost is greater than the effect obtained, and the problem of its own weight makes it easy for the heat-insulating lightweight castable itself to peel off from the wall surface.

The block-like and felt-like ceramic fibers are applied to the heat-insulating lightweight castable using an adhesive binder. When an anchor is embedded, it is firmly fixed by the anchor. By applying this ceramic fiber, the heat insulation can be further enhanced.

In the present invention, immediately after the construction of the lightweight castable, the degree of hardening is measured in the range of φ5 to 20 mm.
When installing a block-shaped or felt-shaped ceramic fiber by embedding a metal anchor stud or ceramic anchor pin into a predetermined position with a hammer (in the case of a ceramic pin, screwing in). It is possible to greatly reduce the workability and work time.

The method of burying and installing the support anchor depends on the temperature conditions at the time of construction, but it is typically installed within about 1 to 5 hours after construction of the insulated lightweight castable, that is, when the castable is not completely hardened. Is preferred. This is because immediately after construction, the strength of the construction body does not reach the level of anchoring, and even if the anchor is buried, it falls immediately even if it is buried. This is because the expression makes it difficult to perform the simple mounting, which is a feature of the present invention. However, this is a standard installation condition, and depending on the temperature conditions of the furnace and the construction body, it is naturally possible to install immediately after construction within 1 hour or at the time when 5 hours or more have passed. It is.

It is preferable that the anchor is buried at a depth up to the boundary with the existing refractory, in order to further firmly fix the anchor. If the burying depth of the anchor is shallow, the thickness of the heat-insulating castable is thin, so that it is difficult to firmly fix the anchor, and the anchor is likely to fall off. Further, the embedded portion of the anchor is preferably a threaded one from the viewpoint that it is more firmly fixed, but it is also possible to use a threadless one that is generally found, and there is no particular limitation.

Further, the pitch at the time of mounting is usually 30
Although it is installed at 0 to 600 mm, it may be installed according to the conditions depending on the construction thickness.

Next, FIG. 2 shows a specific example of the adiabatic fireproof structure of the present invention. In this structure, a lightweight castable 15 is installed on the wall surface of an existing refractory 11, a block-shaped ceramic fiber 13 is installed on the wall surface via an adhesive bander 12, and a ceramic or metal anchor 14 is buried.

[0029]

[Example] In this example, a ceramic fiber block (50 mm) was applied to a heat-insulating lightweight castable having a thickness of 20 to 100 mm (N).
o. 1-4).

The total working time is 48.5 to 50 hours, and the service life (to fall off) of the fiber block is 12 to
It was 15 months. Table 1 shows the results together with the construction thickness.

The cause of the detachment of the ceramic fiber is due to erosion, and the surface condition of the exposed heat-insulated lightweight castable is sound and the adhesive binder has not been melted yet. Was easy.

[Comparative Example] Comparative Example 1 is an example in which a work of peeling a molten layer was performed, and thereafter, a ceramic fiber was applied without applying a lightweight castable. In this comparative example, it took 72 hours for five workers to peel off the molten layer,
A work time of 120 hours was required including the fiber block construction. The service life of the fiber block was 12 months.

The second conventional example is an example in which the melted refractory surface is not peeled off and is directly applied with an adhesive binder and an anchor. Although the work time was 48 hours only for the construction of the fiber block, the result was that all of the fiber blocks dropped out in a short time of only two months.

[0034]

[Table 1]

[0035]

Example 2 Next, the measurement results of the outer shell temperature of the heating furnace in the heat insulating structure of the present invention were compared with those of the conventional structure.

According to the heat insulating structure of the present invention in which a lightweight castable and a fiber block are installed, the furnace temperature 1300
When the surface temperature of the outer shell of the furnace at a temperature of ° C. was measured, it was found that the temperature was 70 ° C., indicating a heat insulating property. Table 2 shows the results.

On the other hand, in the conventional heat insulating structure including only the fiber block, the outer shell surface temperature at the furnace temperature of 1300 ° C. was 90 ° C. In the structure in which neither the lightweight castable nor the fiber block was installed, the outer shell surface temperature at the furnace temperature of 1300 ° C. was 120 ° C. Table 2 shows the results.
It is described together.

[0038]

[Table 2]

[0039]

As described above, according to the present invention, by combining the heat-insulating lightweight castable with the block-like or felt-like heat-insulating ceramic fibers formed on the upper surface, the construction time is reduced, and the fiber block is reduced. Has a long service life, requires only a short rebuilding work, and is easy to use.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a conventional heat-insulated fire-resistant wall structure.

FIG. 2 is an explanatory diagram of a heat insulating wall structure according to the present invention.

[Explanation of symbols]

 11 Existing refractories, 12 bonded vaniders, 13 block-shaped ceramic fibers, 14 ceramic or metal anchors, 15 lightweight castables.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideo Inagaki 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Hiroshi Mitani 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Sun (72) Inventor Kazuaki Matsuo 1st Minamito, Ogakie-cho, Kariya-shi, Aichi Toshiba Cella Co., Ltd. Mix Co., Ltd. Kariya Works F-term (reference) 4K051 AA03 AA04 AA05 AA06 AB09 BB03 BB04 BB07 BC05 DA11 GA06 KA03

Claims (2)

[Claims] An insulation furnace comprising: an industrial furnace furnace wall; a ceramic fiber-containing lightweight castable formed on the wall; and a block-like or felt-like heat-insulating ceramic fiber formed on the upper surface. Fire wall structure. 2. The heat-insulated fire-resistant wall structure according to claim 1, wherein the anchor is buried in a lightweight castable.