JPS6121189B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is applicable to metallurgical furnaces, ceramic furnaces, metal heating furnaces, etc.
This is a monolithic refractory used for gaps that occur or pre-provided between the outer shell and lining of various types of furnaces.

Generally, castable refractories, ceramic fibers, cushioning mortar, etc. are used as fillers between the outer shell of a kiln and the refractory lining layer to provide insulation and absorb the expansion stress of the refractory lining bricks. are doing. Castable refractories have poor fluidity when hot and contain a large amount of moisture, which can cause negative effects on other lining refractories (for example, spalling, etc.)
In addition, unfilled gaps are left in complex-shaped filled areas, and even in those filled areas, as the heating time elapses, the shrinkage increases and creates gaps, resulting in gaps between the lining refractory bricks. The high-temperature gas inside the furnace leaks out, causing the outer shell to become red-hot, oxidized, and perforated. Ceramic fibers and cushioning mortar have insufficient adhesion to the outer shell and lining materials, and to each other, so they scatter and disappear due to air leakage at the end of the furnace operation, resulting in the red heat of the outer shell. There are some problems that may occur.

The present invention eliminates the above-mentioned drawbacks, has good fluidity even in hot conditions, has excellent fire resistance and heat insulation, and has a filling that adheres closely to each other as well as to brick walls and outer shells, and does not require mixing water. It provides materials,
The gist of the present invention is a monolithic refractory for filling gaps in furnace lining walls, which is a mixture of expandable hydrated alkali silicate glass and heat-expandable fireproof heat insulating material.

In the present invention, the foamable hydrated alkali silicate glass used as a binding material (adhesive) with the heat-expandable fireproof insulation material or the lining fireproof brick material is a mixture of fine powder of alkali silicate glass and water or boric acid (B ₂ O ₃ ). Mix the component-containing aqueous solution and the phosphoric acid (P ₂ O ₅ ) component-containing aqueous solution,
It is manufactured to have a moisture content of 10 to 40% (wt%), and especially for purposes such as the present invention, the molar ratio SiO ₂ /M ₂ O (M is Na or K) is used. A mixture of fine alkali glass silicate glass powder having a particle diameter of 1.5 to 4.0 with water and an aqueous boric acid solution is suitable. In addition, this foamable hydrated alkali silicate glass is pre-treated by foaming until it has the same density as the heat-expandable fire-resistant insulation material. It is also possible to prevent the trouble of not being able to fill gaps due to separation of particles and poor adhesion between particles.

The heat-expandable fireproof heat insulating material mixed with foamable hydrated alkali silicate glass is used as a heat resistance increasing material or a volume increasing material, and vermiculite, expanded shale, barlite, etc. are used, and perlite is particularly preferred.

The blending ratio of the expandable hydrated alkali silicate glass and the heat-expandable refractory heat-resistant material is not particularly limited, but depending on the usage conditions of the furnace, increasing the blending ratio of the former may improve the adhesion between particles. increases, but decreases fire resistance; conversely, as the latter increases, the opposite phenomenon occurs, so the large weight ratio is 1:0.3 to 1:3.
A range of 1:0.5 to 1:2 is particularly preferred.

Next, examples of the present invention will be shown.

As shown in Fig. 1, a gap 5 (length 0.5~
1.0m, width 40-70mm), raise the temperature of the outer shell 1 to 250℃ or higher, perforate the gap, and reduce the weight ratio of foamable hydrated alkali silicate glass to fireproof insulation material to 1. The product 6 of the present invention, prepared as: 1, was filled under natural pressure or pressure. For heating, forced heating means such as a burner may be used, but heat retained during use of a kiln may also be used. The product 6 of the present invention filled in the gap 5 fuses while foaming, expands, solidifies, and closes the gap 5 as if it were a single wall.
On the other hand, for comparison, similar tests were conducted using only cushioning mortar.

As a result, the temperature of the outer shell 1 increased again in the gap closed part filled with the cushioning mortar about one month after the closure, but the gap closed part filled with the product of the present invention did not increase in temperature even after one year. It has been used without any problems.

As mentioned above, the monolithic refractory of the present invention for filling gaps in the inner wall of a kiln has high fire resistance and heat insulation properties, prevents the red-hot phenomenon of the outer shell, and prevents the expansion and contraction of the refractory bricks. Not only is it effective as a stress buffer, it is also effective in terms of labor saving, extending the life of the furnace wall.

[Brief explanation of the drawing]

FIG. 1 shows a partial sectional view of a furnace wall in an embodiment of the present invention. 1: Outer shell, 2: Refractory layer, 3: Insulating brick,
4: refractory brick, 5: gap, 6: monolithic refractory of the present invention.

Claims (1)

[Claims] 1. A monolithic refractory for filling gaps in furnace lining walls, which is a mixture of expandable hydrated alkali silicate glass and heat-expandable fireproof insulation material.