JPS6230101B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fireproof insulation brick and a method for manufacturing the same.

Refractory insulating bricks are essential for the thermal economy of furnaces, and are used alone or in combination with various types of refractory bricks and heat insulating boards, and have the function of keeping the furnace warm, that is, reducing the amount of heat dissipated from the furnace walls and the amount of heat stored. For this purpose, fireproof and insulating bricks are required to have various properties. For example JISR2611
These are defined as Class A, Class B, Class C, etc.
A wide variety of fireproof and insulating bricks have been developed and put into practice, but all of them are fireproof and insulating bricks with the same bulk specific gravity, and when various properties are sought, other bricks with different bulk specific gravity (that is, different characteristics) are used. A combination of fireproof and insulating bricks was required. Generally, fireproof and insulating bricks are manufactured by adding and mixing a porosity imparting material to a fireproof material and using one of the following manufacturing methods: extrusion molding, casting molding, or vibration molding. As mentioned above, all of them were fireproof and insulating bricks with the same bulk specific gravity.

Therefore, the present inventors believe that if layers with different bulk specific gravity can be integrated into one fireproof insulation brick, it will be possible to provide each layer with the respective characteristics in one fireproof insulation brick. This invention was developed as a result of various experiments based on the knowledge of the inventors. Therefore, an object of the present invention is to provide a refractory insulating brick as an integral body consisting of layers made of the same material and having different bulk specific gravity, and furthermore, to provide a method for manufacturing such a refractory insulating brick. It is something to do.

The details of this invention will be explained below.

First, the fireproof and insulating brick of the present invention (first invention) will be explained with reference to the drawings. The standard fireproof insulating brick is a hexahedral product having a plane A, a longitudinal face B, and a face C in pairs, as shown in FIG. 1, and the fireproof insulating bricks 1, 2,
3, the plane A, longitudinal surface B, and edge surface C are multilayered 1a, 1b, 1 as shown in FIG. 2 A, B, and C, respectively.
c, 2a, 2b, 2c, 3a, 3b, and 3c. Each fireproof insulation brick layer 1a, 1b, 1
c, 2a, 2b, 2c, 3a, 3b, 3c, the type of pore-imparting material to be added and mixed with the refractory material, respectively;
Fireproof and insulating brick layers 1a, 1b, 1 made of the same material and having different bulk specific gravity with the addition amount adjusted in advance
c, 2a, 2b, 2c, 3a, 3b, and 3c, and are integrated in a laminated state in order of increasing bulk specific gravity, starting from the fireproof and insulating brick layer 1a, 1b, and 1c with the largest bulk specific gravity. . In addition, in the above and below, the term "fireproof and heat-insulating brick layer" refers to each layer of bricks after firing. In the example shown in Figure 2 A, B, and C, three layers are integrated, but the "fireproof and insulating brick layers made of the same material and having different bulk specific gravity" have a large bulk specific gravity no matter how many layers there are. The number of layers is not limited as long as the layers can be integrated in sequence. However, considering the manufacturing method described below, increasing the number of layers more than necessary is not preferable because it requires a large number of molds and reduces molding efficiency. Each fireproof insulation brick layer 1a, 1
b, 1c, 2a, 2b, 2c, 3a, 3b, 3c
The thickness of the colayer can be set freely. Layers with various bulk specific gravity can be arbitrarily combined and integrated, from a dense layer excluding pore-adding material to a bulk specific gravity of 0.3, which is said to be ultra-light. In addition, the fireproof insulation brick layer 1 with the largest bulk specific gravity
a, 2a, and 3a are the heat receiving side, that is, the inner layer to be heated, and the bulk specific gravity thereof is preferably in the range of 1.0 to 1.7 in order to prevent corrosion of impurities in the furnace. Furthermore, in order to maintain the insulation properties of the entire brick, the average bulk specific gravity of the entire fireproof insulation brick is
It is preferably 0.7 to 1.1.

3 and 4 respectively show other embodiments of the fireproof and insulating brick according to the first invention. That is, the third
The figure shows a so-called "mortar" product, which is an irregularly shaped fireproof and insulating brick 4, in which two layers 4a and 4b of "fireproof and insulating brick layers made of the same material but with different bulk specific gravity" are laminated and integrated. ing. Fourth
The figure also shows a product called a "burner tile" made of irregularly shaped refractory and insulating bricks 5, in which three layers 5a, 5b, 5c of "refractory and insulating brick layers made of the same material but with different bulk specific gravity" are laminated. It is integrated.

Next, an example of the use of the fireproof heat insulating brick according to the first invention will be given to explain its operation and effects.

(b) Lining bricks for heavy oil-burning, kiln furnaces are:
Normally, fireproof insulating bricks have a high porosity (low bulk specific gravity), so they absorb unburned heavy oil and heavy oil decomposition products, causing structural spalling.
Generally, fireproof bricks are used on the inside and fireproof and insulating bricks are used on the outside. However, the thickness of the lining refractory bricks was 114 mm or 230 mm, which was larger than that of standard bricks, resulting in a considerable thickness of the furnace wall and a large amount of heat storage in the furnace. However, according to this invention, the inner layer (dense layer) to be heated, which corresponds to conventional firebricks, has a thickness of around 30 mm. Form a dense layer with a large bulk specific gravity equivalent to conventional firebricks with a thickness of around 30 mm on the inner layer to be heated facing the surface, and make the other layers each have a different bulk specific gravity and laminate them together. For example, by using the refractory and insulating bricks according to the present invention, it is possible to reduce the thickness of the entire furnace wall, and the amount of heat storage is also reduced, resulting in significant energy savings.

(b) Spinel fireproof and insulating bricks, which are resistant to erosion by molten steel and slag, have a higher porosity (lower bulk specific gravity) than firebricks, so they have excellent insulation properties, but their erosion resistance is inferior to firebricks. be. Therefore, if spinel fireproof insulation bricks are used to insulate a steelmaking furnace, the thickness of the fireproof insulation bricks must be 65 mm even in the thinnest standard shape of firebricks, and the thickness of the lining firebricks must be increased accordingly. There was a problem with the layer becoming thinner. However, in the fireproof insulating brick according to the present invention, the first layer (inner layer to be heated) is a dense layer with a thickness of 20 mm and has a bulk specific gravity of 1.70; the second layer is a heat insulating layer with a thickness of 25 mm and has a bulk specific gravity of 1.15; If you create a three-layered structure with a 20mm thick ultra-light layer with a bulk specific gravity of 0.60 and an overall average bulk specific gravity of 1.15, it will have significantly greater erosion resistance even though it is 65mm thick, the same size as conventional fireproof and insulating bricks. Therefore, even if the layer of refractory bricks is made thinner, the overall erosion resistance can be improved, and of course, it is also possible to expect a better insulation effect than before.

(c) When conventional refractory insulating bricks are used in gas carburizing furnaces, the raw gas such as butane that is blown into the furnace during seasoning may thermally decompose, resulting in carbon adhesion that may cause surface peeling, so it is energy-saving. It was difficult to select lightweight fireproof and insulating bricks based mainly on And the bulk specific gravity of the fireproof insulation bricks currently in general use is
It ranks 0.8.

Therefore, the fireproof and insulating brick according to the present invention was
If the three-layered product has a bulk specific gravity of 1.0 with a layer thickness of 35 mm; a bulk specific gravity of 0.7 with a second layer thickness of 34 mm; and a bulk specific gravity of 0.4 with a third layer thickness of 35 mm, the average bulk specific gravity of the whole is 0.7. is denser and has a lower average bulk density than the currently used fireproof and insulating bricks, so by using it in place of conventional fireproof and insulating bricks,
It is possible to form a furnace lining wall that has improved corrosion resistance against carbon and can also be expected to have an energy saving effect.

Next, a method for manufacturing a fireproof and insulating brick according to the second invention will be explained. Fireproof and insulating bricks have conventionally been manufactured by extrusion, casting, or vibration molding methods, and although this second invention also falls under the above-mentioned manufacturing method based on cast molding in a broad sense, conventional general cast molding is not required. Unlike, the type of pore-adding material,
A plurality of slurry clays of fireproof and insulating brick materials are prepared which are made of the same material and have different slurry specific gravity adjusted by the amount of slurry added, a plurality of formworks are similarly prepared according to the slurry specific gravity of these slurry clays, and 1. By casting one type of slurry clay into one mold, stacking another mold on the previous mold, casting another slurry clay again, and repeating these steps, the same material can be made. At the same time, a molded body is obtained by laminating fireproof and insulating brick materials with different slurry specific gravity in order of bulk specific gravity, and furthermore, by drying and firing, it is finally possible to form a laminated body of fireproof and insulating brick layers made of the same material but with different bulk specific gravity. The second invention has a major feature different from the conventional one in that it obtains a product that has been modified (that is, a product according to the first invention). In the above and below, the term "fireproof and heat-insulating brick agent" refers to a brick material before firing.

Details of this second invention will be explained with reference to embodiments and drawings (FIG. 5). First, two or more types of slurry clay of the same material but different slurry specific gravity of fireproof and insulating brick materials are prepared. The materials that can be used to form this slurry are diatomaceous earth, fireclay, high alumina, alumina, spinel,
Any material for current fireproof and insulating bricks, such as magnesia silicate, can be used, and porosity-imparting materials such as expanded polystyrene, sawdust, and expanded vermiculite can be added to these fireproof and insulating bricks depending on the type and type. It is added and mixed by adjusting the amount. Then, using a number of molds with a predetermined shape corresponding to the number of slurry clay prepared, one type of slurry clay is cast into one mold, and then other molds are stacked on top of it. Then, other types of slurry clay are cast and these steps are repeated, and when a predetermined number of laminated layers is satisfied, the mold is demolded to form a molded body. Then, this laminated molded body is subjected to the usual drying, firing, and finishing processes to obtain a final product in which fireproof and insulating brick layers are laminated and integrated, but are made of the same material but have different bulk specific gravity.

Examples are shown below.

Sludge clay C1 (sludge specific gravity 1.30), slurry clay B5 (sludge specific gravity 1.07), and slurry clay A5 (sludge specific gravity 0.87) of the same 1300°C class were prepared and prepared using the same fireproof insulation bricks. In each slurry, foamed polystyrene was used as the pore-adding material. Next, as shown in FIG. 5, the lower formwork 7 is placed on the bottom plate 6, the slurry clay C1 is poured into it, and the excess is scraped off, and then the middle formwork 8 is stacked on the lower formwork 7. Slurry clay B5 was poured into the mold, and after scraping off the excess, the upper formwork 9 was further stacked on the middle formwork 8, and slurry clay A5 was cast therein, and the excess was also scraped off. After being left for 5 hours, the lower formwork 7, the middle formwork 8, and the upper formwork 9 were removed from the molds, and the molded body together with the bottom plate 6 was placed on a drying trolley, dried, and subjected to the various steps of firing and finishing.

The quality of the resulting fireproof and insulating bricks having the same shape as in Figure 2A was as follows.

Bulk specific gravity Overall 0.79 1st layer 1.06 2nd layer 0.75 3rd layer 0.56 Compressive strength Overall 35Kg/cm ² 1st layer 60 〃 2nd layer 29 〃 3rd layer 18 〃 Reheating shrinkage rate Overall 0.52% ( However, 1300℃×8hr) Thermal conductivity Overall 0.22Kcal/m ² hr℃ (However, 350℃±10℃) 1st layer 0.29 〃 2nd layer 0.22 〃 3rd layer 0.16 〃 Next, the fireproof insulation according to the third invention Explain how bricks are manufactured. The method for manufacturing a fireproof and insulating brick according to the third invention includes preparing two or more kinds of soft mud clay of fireproof and insulating brick materials, which are made of the same material and have different bulk specific gravity, in which the type and amount of pore-adding material are adjusted in advance. A mold of a predetermined shape is filled with soft mud clay having the largest bulk specific gravity, vibration is applied, other molds are stacked on top of it, and soft mud clay having a smaller bulk specific gravity is filled again. After filling and applying vibration, soft mud clay having different bulk specific gravity is sequentially packed and vibration is applied, followed by demolding, drying, and firing.

In the above and the following explanations, "soft clay" means a soft clay that can be removed immediately after filling the formwork and applying vibration. This means that it can be controlled by the specific gravity of the packed bulk.

Although the method for manufacturing fireproof and insulating bricks according to the third invention falls within the concept of the vibration molding method described above in a broad sense, it differs greatly from conventional manufacturing methods in the following points. That is, two or more types of soft mud clay for fireproof and insulating brick materials are prepared, each of which is made of the same material and has a different bulk specific gravity, with the type and amount of pore-adding material adjusted in advance, and a plurality of clay clays corresponding to the types of these soft mud clay are prepared. The first step is to prepare a formwork, fill one formwork with one type of soft clay, apply vibrations, stack another formwork on top of the previous one, and then fill it with another formwork. By repeating these steps of filling and applying vibrations, a molded body made of laminated layers of refractory and insulating bricks made of the same material but with different bulk specific gravity can be obtained, and furthermore, by drying, firing, and finishing processing. It differs from the conventional manufacturing method based on vibration molding in that it ultimately obtains a product in which layers of refractory and insulating bricks made of the same material and having different bulk specific gravity are laminated and integrated (i.e., the product according to the first invention). This invention is also different from the second invention.

To explain this third invention with reference to examples and drawings (Fig. 6), first, the material of the fireproof heat insulating material and the pore imparting material to be added thereto are appropriately selected in the same manner as the second invention. Two or more kinds of soft mud clay of fireproof and insulating brick materials are prepared, which are made of different materials but have different bulk specific gravity. Then, molds of predetermined shapes are prepared in advance according to the number of types, and soft mud clay, which has the greatest bulk ratio, is packed into each mold and subjected to vibration. Further, another formwork is stacked on top of the previous formwork, and another soft mud clay having a bulk specific gravity smaller than that of the previous soft mud clay is packed and vibration is applied. After repeating these steps and satisfying the predetermined number of layers, the mold is demolded to form a molded product, which is then subjected to the usual drying, firing, and finishing processes to create fireproof products made of the same material but with different bulk specific gravity. A final product is obtained in which the insulation brick layers are laminated and integrated.

Next, examples will be shown.

1500℃ class soft clay C3 (bulk specific gravity 1.48) and A7 (bulk specific gravity) using the same fireproof insulation material
1.01) was adjusted and prepared. As the pore-imparting material, "sawdust" was used for the soft mud clay C3, and foamed steel was used for A7. Then, as shown in Fig. 6, the soft mud clay C3 is packed into the lower formwork 11 placed on the floor plate 10, subjected to gentle vibration 12 times, and scraped off the excess on the upper surface side, which has become a smooth surface. Frame 1
2 was stacked on the lower formwork 11 and the soft clay clay A7 was packed in the same way and subjected to gentle vibration 12 times. Both the lower and upper formworks 11 and 12 were demolded, and the molded body together with the floor plate 10 was placed on a drying trolley. The material is then placed on a holder and subjected to various processes including drying, firing, and finishing. The quality of the thus obtained two-layer fireproof and insulating brick (see FIG. 1A) was as follows.

Bulk specific gravity Overall 0.90 1st layer 1.23 2nd layer 0.68 Compressive strength Overall 61Kg/cm ² 1st layer 120 〃 2nd layer 27 〃 Reheating shrinkage rate Overall 0.15% (1500℃×8hr) Thermal conductivity Overall 0.29Kcal/m ² hr℃ (350℃±10℃) 1st layer 0.42 〃 2nd layer 0.20 〃 The method for manufacturing the fireproof and insulating bricks according to Fig. 2 and the third invention is as explained above. However, the reason why the second invention specifies a molding method in which slurry clay is cast is because in press molding, the lightweight aggregate is destroyed by the press pressure during molding, making it impossible to obtain a lightweight fireproof and heat-insulating lens. Similarly, in extrusion molding, the spiral kneader (auger machine) used for extrusion molding is a device intended for even more homogeneous kneading, and although it is suitable for molding heavy fire-resistant and insulating bricks, it is not suitable for molding ultra-light fire-resistant and insulating bricks. That's also why. Also, in the third invention, the soft mud clay with a large bulk specific gravity is placed on the bottom and the soft mud clay with a smaller bulk specific gravity is placed on top.If this is reversed, the light layer of clay below will be damaged due to vibration. This is because the heavier layer floating upward sinks downward and mixes, making it impossible to obtain the intended layered brick.

There is also a method of gluing together several fireproof and insulating bricks with different bulk specific gravity using mortar to create a laminated fireproof and insulating brick with different bulk specific gravity as a whole, but the bricks obtained by this method are said to be made by gluing small pieces of bricks together. Low work efficiency is unavoidable, and the ratio of the mortar layer made of a material different from the brick material in one brick increases.Moreover, the sodium silicate in the mortar penetrates into the bonding surface of the fireproof and insulating bricks. This is preferable because if it reacts with the brick material due to the high heat in the middle furnace, it will vitrify and cause cracks along the adhesive surface of the mortar, lowering the fire resistance of that area and eventually causing peeling and falling off. It's something that doesn't exist.

As explained above, according to the present invention, one refractory insulating brick is formed by laminating and integrating refractory insulating brick layers made of the same material and having different bulk specific gravity (first invention), In this case, since we decided to perform casting molding of slurry clay (second invention) or vibration molding of soft mud clay (third invention), we achieved excellent wear resistance, fire resistance and heat insulation properties, erosion resistance, fire resistance heat insulation properties, and scratch resistance. It is now possible to obtain various properties such as poling properties and fireproof insulation properties in a single brick, which were originally required for different fireproof and insulation bricks, and can be made into standard or irregular shapes depending on the purpose. It is possible to efficiently obtain a refractory brick having a plurality of intended properties.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a standard type of fireproof insulating brick, Fig. 2 A, B, and C are perspective views of a standard type fireproof insulating brick each showing an embodiment of this invention (first invention), and Fig. 3 and Fig. 4 are perspective views of irregularly shaped fireproof and insulating bricks showing examples of this invention (first invention), and Fig. 5 shows the stacked state of formwork and slurry clay used in this invention (second invention). FIG. 6 is a partially cutaway perspective view showing the state of casting of molds, and FIG. . A...Plane, B...Longitudinal surface, C...Edge surface,
1, 2, 3, 4, 5... Fireproof insulation brick, 6, 1
0...Sillboard, 7,8,9,11...Formwork.

Claims (1)

[Scope of Claims] 1. A plurality of fireproof and insulating brick layers made of the same material and adjusted to have different bulk specific gravity depending on the type and amount of the pore-imparting material are laminated and integrated in order of increasing bulk specific gravity, and Among the fireproof and insulating brick layers, the one with the largest bulk specific gravity has a bulk specific gravity of 1.0 to 1.7.
A fireproof and insulating brick, characterized in that the inner layer is heated, and the average bulk specific gravity of the entire brick is 0.7 to 1.1. 2. Prepare two or more types of slurry clay for fireproof and insulating brick materials, which are made of the same material and have different slurry specific gravity depending on the type and amount of pore-adding material, and first form a formwork with a predetermined shape. A type of slurry clay is poured into the mold, and then another mold is stacked on top of it, and the process of casting other types of slurry clay is repeated. After casting in order of slurry specific gravity, it is demolded, dried, and fired, and the slurry clay with the highest slurry specific gravity has a bulk specific gravity of 1.0.
1. A method for producing a fire-resistant and heat-insulating brick, characterized by forming a layer of fire-resistant and heat-insulating brick with a thickness of 1.7 and an average bulk specific gravity of the entire brick of 0.7 to 1.1. 3. Prepare two or more types of soft mud clay of fireproof and insulating brick material, which are made of the same material and whose bulk specific gravity is adjusted to differ from each other depending on the type and amount of pore-adding material, and then first formwork with one predetermined shape. A type of soft mud clay is packed in the mold and vibration is applied. Next, another formwork is stacked on top of it, and the process of filling with other types of soft mud clay and applying vibration is repeated. After filling different soft mud clay from the bottom in descending order of bulk specific gravity, they are demolded, dried, and fired, and the soft mud clay with the highest bulk specific gravity has a bulk specific gravity of 1.0.
1. A method for producing a fire-resistant heat-insulating brick, characterized in that the layer has a fire-resistant heat-insulating brick layer of ~1.7, and the average bulk specific gravity of the entire brick is 0.7-1.1.