JPH1054670A - Forming method of furnace structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen scattering of dust to the periphery, to increase the bulk specific gravity if a constructed body and to enable use of porcelain earth for a portion to be brought into contact with molten metal by a method wherein the porcelain earth wherein a quick setting agent is mixed together with compressed air is sent by a nozzle piping to a spray nozzle connected to the fire end thereof. SOLUTION: A porcelain earth of unshaped refractory having self-fluidizing properties is sent under pressure to a site of construction by a pressure sending pump 31 and a pressure sending piping. After a quick setting agent is injected into the porcelain earth, the porcelain earth is agitated by a turbulent flow while it passes through a nozzle piping 33, and thereby the agent is dispersed well in the porcelain earth. By mixing necessary water in the parcelain earth beforehand, the distribution of the water in the porcelain earth is made uniform and almost no accompanying air is present around grains in the porcelain earth before compressed air is injected therein, while almost all bubbles caught up at the time of the injection of the compressed air, a porcelain earth carrier, are released from the porcelain earth on the execution of execution of construction by spraying. As the result, a constructed body of the unshaped refractory of which the porosity is small and the bulk specific gravity large is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a furnace structure used for contacting a molten metal having excellent workability and durability.

[0002]

2. Description of the Related Art In recent years, the use of irregular-shaped refractories has been increasing in the construction of various furnaces from the viewpoint of labor saving of work.
Japanese Patent Publication No. 59-37431 discloses a method for preparing an amorphous refractory composition having a low water content containing alumina cement and an ultrafine powder having a particle size of 1 micron or less as an essential component, placing the mixture in a mold having a predetermined shape, and drying by molding. A strong and dense precast molded product is installed at intervals, and the gap between these large blocks is integrally formed by vibrating filling with an amorphous refractory composition having the above composition and integrally formed. The structure is disclosed. Furnaces having the structure of Japanese Patent Publication No. 59-37431 are suitable for use in aluminum melting furnaces, holding furnaces, etc., and have been able to stably withstand long-term use, while filling gaps between large and dense refractory bricks (blocks). It is also desirable that the amorphous refractory composition (hereinafter referred to as a filling amorphous refractory composition) be dense.

[0003] In order to solve these problems, a combination of an ultrafine powder and alumina cement has been used as an amorphous refractory composition for filling to be poured and vibrated.

However, when this composition is applied to a hearth or a furnace wall of a refractory furnace structure by vibrating construction, it is necessary to attach and remove a formwork, which requires a great deal of labor. In addition, the kneaded clay such as high-strength dense castable is very hard, and it is difficult to mechanically transport such as pumping, so the kneaded clay outside the refractory structure is put in a bucket and manually placed. There was a problem that a great deal of labor such as transportation was required.

[0005] It is conceivable to use a spraying material as an irregular refractory composition for filling which is excellent in workability, and to spray the material between the bricks to form an integrated structure. Then, it was difficult to form a dense integrated furnace structure.

That is, the conventional spraying method is a so-called dry or semi-dry spraying method, and is a method for a clay material having no fluidity, that is, a dry powder composition for an amorphous refractory or an amorphous refractory. The powder composition is mixed with an amount of water that does not exhibit fluidity, and the moist clay is transported to the construction site by piping using compressed air as a carrier, and the water required or insufficient by the blowing nozzle with the amorphous refractory The sprayed water is injected and sprayed from the spray nozzle.

However, according to such a method, fine particles of, for example, 0.1 mm or less in the amorphous refractory powder composition in the kneaded material are sprayed in a state in which the particles of the refractory powder are in a dispersed state and insufficiently wet. Because it is constructed, a lot of air is taken into the clay of the spray-formed irregular-shaped refractory, and as a result, the molded body of the spray-formed irregular-shaped refractory is cast and cast. The porosity is large (the bulk specific gravity is small) as compared with the construction body of No. 1, and the refractory properties such as corrosion resistance are inferior to the extent that the porosity is large. Therefore, it has not been used in the refractory furnace structure for the purpose of coming into contact with the molten metal.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and to further reduce the labor required for construction using an amorphous refractory, and to reduce dust to the surroundings. Provided is a method for forming a refractory furnace structure which has a small bulk and a large volume specific gravity due to reduced scattering and a reduced porosity of a furnace structure as a construction body, and which has excellent characteristics as a refractory and can be used in a portion in contact with molten metal. Is to do.

[0009]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and comprises a plurality of fixed refractories having a predetermined shape arranged at intervals, and a gap between these fixed refractories. In addition, a self-flowing clay obtained by adding water and kneading to an amorphous refractory composition containing a refractory aggregate, a refractory powder and a dispersant is pumped to a construction site by a pump and a pumping pipe. Compressed air and a required amount of quick-setting agent are respectively injected into the kneaded clay from the compressed air injection port and the quick-setting agent injection port provided in the downstream portion of the pipe, and the kneaded material in which the quick-setting agent is mixed with the injected compressed air. The present invention provides a method for forming a furnace structure, wherein a nozzle pipe is fed to a spray nozzle connected to the tip of the furnace, and the clay is sprayed from the spray nozzle to be integrated with a fixed refractory. .

A typical example of the present invention will be described first with reference to FIGS.

Although the refractory furnace structure shown in FIG. 1 has various shapes such as a cylindrical shape and a box shape, it basically comprises a furnace bottom part 1, a side wall part 2, and a ceiling part 3 and is provided inside a casing of a steel shell (not shown). A refractory is built in the furnace to form a refractory furnace. Reference numeral 10 denotes the liquid level of the molten metal when the apparatus is operated. Note that auxiliary functions such as a raw material insertion port, a molten raw material discharge port, a heating burner, and a flue of burner exhaust gas are not shown. .

Here, the furnace bottom 1 shows a furnace structure formed by the method of the present invention. In other words, the furnace bottom 1 is cast by applying vibration to the heat-insulating castable layer 1-1 (hereinafter referred to as vibration construction).
Then, a plurality of precast blocks 1-4 (high-strength dense castables are kneaded with a small amount of water in advance on the refractory castable 1-2 to form a kneaded clay, and the kneaded clay is formed into a predetermined shape. Placed in a mold and dried) are placed at intervals and the precast block 1-
The spray construction body 1-3 is spray-constructed into the gap of No. 4 and integrated. Here, the shape of the furnace bottom 1 can be designed not only in a plane but also in a shape suitable for holding the molten metal, such as a spherical shape.

In FIG. 1, a side wall 2 and a ceiling 3
Vibrates the heat-insulating castables to build the heat-insulating layer 2-1, the vibration-resistant castables 2-2, and finally the high-strength dense castables 2-3 and 2 in contact with the upper surface 10 of the molten metal. 3 shows an example in which a high-strength dense castable or a refractory castable 2-4 which is located above and which does not contact the molten metal is vibrated.

According to FIG. 1, the furnace structure formed by the present invention is only the furnace bottom. However, the present invention is not limited to the furnace bottom, and may be used for forming the furnace wall in some cases. Applicable. The application of the present invention may be a desired part of the furnace bottom, the furnace wall, and the ceiling, or may be the whole.

FIG. 2 is a top view of the furnace bottom that comes into contact with the molten metal formed between the plurality of precast blocks 1-4 as the fixed refractories shown in FIG. 1 by filling and integrating the gaps by the spraying method of the present invention. It shows the state.

The present invention provides a so-called dense joint to be filled between them in order to take advantage of the formation of a furnace structure having good workability using such a dense and large-sized fixed refractory (block). This is a significant feature of the method for spraying irregular shaped refractories for filling.

In the present invention, the fixed refractory to be installed with a gap may be any type including a conventionally used refractory brick formed by press molding. In order to maximize the advantages of applying the mounting method, it is necessary to use a large and dense one.

A large, dense, fixed refractory can be easily formed by kneading a predetermined amorphous refractory composition together with a small amount of water into a kneaded material, placing the kneaded material in a mold having a predetermined shape, and forming and drying the kneaded material. The obtained precast block is high strength and dense and useful.

The precast blocks, usually (although the shape is typically 3-6 square approximately rectangular, circular, not harm any even polygonal) surface area facing the furnace as 500 cm ² or more, preferably When used as a material having a size of 1500 cm ² or more, a remarkable effect can be obtained for the intended improvement of workability and durability. Further, the precast block preferably has a groove in the side wall in the thickness direction in advance, and as a particularly remarkable effect, a stronger integrated structure in a form in which the layer subjected to dense spraying has entered the groove. Since it is formed, it is easy to prevent the permeation of the molten metal even if cracks occur at the boundary with the precast block.

In the present invention, since a dense integrated furnace structure can be formed, even a fixed refractory such as a precast block has a bulk specific gravity of 2.2 or more and an apparent porosity of 15% or less. From the compressive strength in cold and 50
It is effective to use one having physical properties of 0 kg / cm ² or more.

The spacing between fixed bricks such as precast blocks is preferably 50 mm or more, and more preferably 75 mm or more. Filling by dense spraying can be performed satisfactorily. This is not preferable because air is trapped inside and defects are easily generated.

Hereinafter, the features of the spraying construction according to the present invention will be described in detail.

The main feature of the spraying construction method of the present invention is that the clay of self-flowing amorphous refractory is pressure-fed to a construction site by a pressure pump and a pressure pipe. According to this method, the kneaded clay of the irregular-shaped refractory which has been previously mixed with the required moisture can be sent to the construction site by the pressure pump and the pumping pipe. The distribution of water is even, and there is almost no air accompanying the particles around the kneaded material until the compressed air is injected, and most of the air bubbles that are entrained when the compressed air, which is a carrier, are injected into the kneaded material. Is released from the kneaded clay at the time of spraying construction, and as a result, a construction body of an amorphous refractory having a small porosity and a large bulk specific gravity is obtained.

In the spraying method of the present invention, a required amount of quick-setting agent is injected into the clay in addition to the compressed air, and is sprayed from the spray nozzle to the work site having the heat insulating layer through the nozzle pipe. The fluidity of the kneaded material rapidly decreases after being poured. Because of this, not only is the moisture absorbed by the insulation layer unnecessarily,
For example, even if the clay is sprayed on a vertical wall, the clay can be applied without flowing down from the sprayed wall. Further, since the spray nozzle is connected to the tip of the nozzle pipe, only one pipe is required to be connected to the spray nozzle, and the operation of moving the spray nozzle up, down, left, and right is easy. Further, preferably, the nozzle pipe is made flexible and the nozzle pipe is easily bent, so that the spraying work by hand can be facilitated.

It is preferable that the injection point of the quick setting agent is located downstream of the compressed air inlet or at the same position as the compressed air inlet. The kneaded material after the quick-setting agent has been rapidly hardened is sent to the spray nozzle through the nozzle pipe in a state where it is rapidly hardened, and is sprayed from the spray nozzle. The clay after injecting the quick setting agent is
Turbulent agitation during passage through the nozzle pipe causes the powder to be more well dispersed in the clay, and as a result, the required amount of quick-setting agent injected into the clay can be reduced. The length of the nozzle pipe is preferably 100
The effect of turbulent agitation can be obtained by setting the diameter to at least mm.

If the nozzle pipe is not provided, or if the quick-setting agent injection port is provided in the spraying nozzle portion, poor dispersion or quick-setting failure of the quick-setting agent may occur, causing dripping of the clay after spraying,
It is not preferable to inject a large amount of quick-setting agent in order to prevent this, because it causes blockage at the spray nozzle portion or causes deterioration in refractory performance.

The pressure feeding pipe and the nozzle pipe move at positions sprayed by hand, but the pipe is 50 A or more (JIS-G345) in order to reduce the pressure feeding load to the pump.
2, the same applies hereinafter) is preferable, and when the inside of the pipe is filled with the clay, the weight becomes considerable.

Here, the injection point of the quick-setting agent is provided downstream of the injection port of the compressed air, more preferably at least 1 m downstream, so that the clay in the pipe downstream from the injection port of the compressed air is in an air-fed state. Therefore, the piping weight is reduced, and handling by hand becomes easy.

If the injection point of the quick setting agent is set at the same position as the injection port of the compressed air, the air feeding load section of the kneaded clay after the quick setting only needs to be at the nozzle pipe portion, and the amount of air to be injected can be reduced.
In particular, since the construction is performed with a low amount of water, the amount of dust generated during spraying construction can be reduced. Here, the pressure feed pipe upstream of the nozzle pipe is filled with kneaded material and becomes heavy.
It is preferable to be around 0A.

In a preferred embodiment in which the injection point of the quick-setting agent is located at the same position as the injection port of the compressed air, a part or all of the compressed air injected into the kneaded material is used. You. In particular, when all of the compressed air injected into the kneaded material is used to inject the quick-setting agent, the compressed air is injected into the kneaded material through a common pipe together with the quick-setting agent. It can save its own piping to inject.

In the present invention, it is preferable to evaluate the fluidity of the clay at room temperature of about 20 ° C. using a cone type. That is, the kneaded material immediately after kneading by adding water of about 20 ° C. to the powder composition, immediately after kneading into a cone-shaped cone having an upper end inner diameter of 50 mm, a lower end inner diameter of 100 mm, and a height of 150 mm and open upper and lower ends. The kneaded material is poured and filled, and the cone shape is withdrawn upward and left to stand for 60 seconds. The diameter is indicated by the diameter (average value obtained by measuring the spread in two directions, hereinafter referred to as flow value).

When the flow value is 165 mm or more, the clay exhibits self-fluidity. However, it is necessary to be able to easily and stably send the kneaded clay kneaded by the pressure pump and the pressure pipe to the construction site, and the flow value of the clay kneaded by the pressure pump to be 180 mm or more, and further 200 mm or more. Is preferred. If the clay having a large flow value is used, the suction resistance of the pressure pump and the flow resistance in the pressure pipe can be reduced, the diameter of the pressure pipe can be reduced, and the long path pressure of the clay can be realized.

In the present invention, the gaps between the fixed refractories are filled by such a spraying method, so that the refractories can be made as dense as the fixed refractories. That is, even with spraying, a bulk specific gravity of 2.2 or more and an apparent porosity of 15% or less are possible, and a desirable furnace structure integrated with a fixed refractory can be formed.

The amorphous refractory composition used in the method for forming a refractory furnace structure of the present invention contains a refractory aggregate, a refractory powder and a small amount of a dispersant.

Examples of the refractory aggregate include alumina, bauxite, diaspore, mullite, ban shale, chamotte, quartzite, pyrophyllite, sillimanite, andalusite, chromite, spinel, magnesia, zirconia, zircon, chromia, One or more selected from carbon such as silicon nitride, aluminum nitride, silicon carbide, boron carbide and graphite, titanium boride and zirconium boride can be preferably used, but not limited thereto, and known metal oxides and metal carbides , Metal nitrides, metal borides, and composites thereof can be used as appropriate.

As the refractory powder, alumina cement,
Alumina, titania, bauxite, diaspore, mullite, ban earth shale, chamotte, silica, pyrophyllite, sillimanite, andalusite, chromite, spinel, magnesia, zirconia, zircon, chromia, silicon nitride, aluminum nitride, aluminum nitride, silicon carbide , And at least one selected from amorphous silica such as boron carbide, titanium boride, zirconium boride, and fumed silica and having an average particle size of 30 μm or less.

As a part of these refractory powders, it is preferable to use ultrafine powder having an average particle diameter of 10 μm or less, preferably 5 μm or less, such as alumina or fumed silica. The use of ultrafine powder of alumina or fumed silica can reduce the amount of water mixed with the composition, and can impart good fluidity to the kneaded clay.

When alumina cement is used as a part of the refractory powder, the alumina cement contributes to the bonding of the refractory for casting, and the construction can provide practical strength in a wide range from normal temperature to high temperature. .

As the dispersant used to impart fluidity to the kneaded clay, at least one selected from polymetaphosphates, polycarboxylates, polyacrylates and β-naphthalenesulfonates can be preferably used. .
The dispersant is preferably added in an amount of 0.02 to 1 part by weight based on 100 parts by weight of the total amount of the refractory aggregate and the refractory powder in the composition.

The amount of water mixed in the composition varies depending on the specific gravity and porosity of the refractory aggregate and refractory powder contained in the composition. There is a lower limit to the amount of water that can impart fluidity to the kneaded clay, and usually, a water amount of 4 parts by weight or more is required for 100 parts by weight of the total amount of the refractory aggregate and the refractory powder. Also,
In order to reduce the porosity of the refractory after construction and ensure good physical properties as a refractory, the amount of water mixed into the composition is 100 parts by weight of the total amount of the refractory aggregate and the refractory powder. Is preferably 15 parts by weight or less with respect to If the amount of water mixed with the composition is large, the refractory aggregate tends to settle, and the applied refractory tends to be heterogeneous.

As a quick setting agent to be injected into the kneaded material, a quick setting agent in an aqueous solution can be used. However, in order to secure a good refractory property by keeping the amount of water in the kneaded material to be sprayed to a minimum. , Preferably a powder. The powder quick-setting agent is preferably injected into the kneaded material from the quick-setting agent injection port using compressed air as a carrier. When injecting the quick setting agent of the aqueous solution into the kneaded clay, it is preferable to use an aqueous solution that is as dense as possible. The quick-setting agent is preferably injected into the kneaded material using compressed air as a carrier so as to be uniformly dispersed.

As the quick setting agent, sodium aluminate,
Aluminates such as potassium aluminate and calcium aluminate, carbonates such as sodium carbonate, potassium carbonate, sodium bicarbonate and potassium bicarbonate, sulfates such as sodium sulfate, potassium sulfate and magnesium sulfate, CaO.Al ₂ O
_{3, 12CaO · 7Al 2 O 3} , CaO · 2Al 2 O 3, 3CaO · Al 2 O 3,
_{3CaO · 3Al 2 O 3 · CaF} 2, 11CaO · 7Al 2 O 3 · CaF 2 Calcium aluminate such as, calcium oxide, selected from calcium hydroxide and their composites or mixtures 1
More than species can be used.

Since the required amount of the quick-setting agent varies to some extent depending on the type of the quick-setting agent, the injection amount is adjusted according to the type of the quick-setting agent and the length of the nozzle pipe after the quick-setting agent is injected. Is preferred.

The injection amount of the quick-setting admixture is 0.00 on a dry basis with respect to 100 parts by weight of the powder composition excluding water and the dispersant.
Preferably, the amount is 5 to 3 parts by weight. If the amount is less than 0.05 parts by weight, even if the quick-setting agent has good performance, the quick-setting speed is insufficient, and the clay that has been sprayed and formed will flow down.
If a large amount is added in excess of parts by weight, the composition hardens rapidly and makes spraying work difficult, and the performance as a refractory such as heat resistance and corrosion resistance deteriorates.

As a commercially available pump, a piston type or squeeze type pump is preferably used. The squeeze type refers to a pump or the like that presses a kneaded material by pressing an elastic tube with a roller. As these pumps, it is preferable to use a pump having a plurality of tubes or a plurality of pistons so as to reduce the pulsation of the clay to be pumped.

[0046]

Embodiments of the present invention will be described below.

Example 1 Al ₂ O ₃ and SiO _{2 were} used as refractory aggregates.
And Fe ₂ O ₃ content of 89% by weight and 7% by weight, respectively
And 1.3% by weight with a particle size of 1.68 to 5 mm
A bauxite aggregate composed of coarse particles having a coarse particle diameter of 0.1 to 1.68 mm and coarse particles having a particle diameter of 0.02 to 0.1 mm and an average particle diameter of 0.02 mm was used.

(Examples 2, 3) Al ₂ O ₃ ,
The contents of SiO ₂ and Fe ₂ O ₃ were 43% by weight and 53%, respectively.
% And 0.9% by weight, having a particle size of 1.68 to
5 mm coarse particles, medium particles having a particle size of 0.1 to 1.68 mm, and 0.02 to 0.1 mm with an average particle size of 0.03 m
m-grained chamotte aggregate was used.

As the refractory powder, the contents of Al ₂ O ₃ and CaO are 55% by weight and 36% by weight, respectively, and the average particle size is 9 μm.
Alumina cement, Bayer alumina with 99.6 wt% Al ₂ O ₃ purity and 4.3 μm average particle size and fumed silica with 93 wt% SiO ₂ purity and 0.8 μm average particle size Was. In addition, powders of sodium tetrapolyphosphate having a content of P ₂ O ₅ and Na ₂ O of 60.4% by weight and 39.7% by weight, respectively, were used as dispersants.

The refractory aggregate, the refractory powder and the dispersant were prepared, and the amount of water shown in Table 1 was added to each of the compositions (the refractory aggregate and the refractory powder were the inner weight% and the others were the outer weight%). Hanging weight%)
And add 3 in a 500 kg vortex mixer.
The mixture was kneaded for a minute to obtain kneaded clay. The fluidity of each kneaded material is such that the kneaded kneaded material is poured immediately after kneading into a cone-shaped cone shape having an upper end inner diameter of 50 mm, a lower end inner diameter of 100 mm, a height of 150 mm, and upper and lower ends opened. The spread diameter when the sample was pulled out and allowed to stand for 60 seconds was measured in two directions, and the average value was defined as the flow value.

The quick-setting agent is a powder having a particle size of 800 μm or less and an average particle size of about 150 μm, and comprises sodium aluminate (containing about 20% of water of crystallization) and sodium carbonate:
Using the material containing at a weight ratio of 1, the kneaded clay of the formulation shown in Table 1 was adjusted, and the spraying construction device having the configuration shown in FIG.
The spraying was performed in a temperature range of 20 to 25 ° C.

The spraying is carried out on a refractory layer corresponding to the refractory castable layer 1-2 assuming the bottom of the refractory furnace shown in FIG.
A precast block of 0 mm (thickness) (a high-strength dense castable is kneaded with a small amount of water in advance to obtain a kneaded material, and the kneaded material is put into a mold and dried and formed.
A bulk specific gravity of 2.90, an apparent porosity of 11.0%, and a compressive strength of 1200 kg / cm ² at normal temperature) was changed to 450 mm × 350 mm (surface area of 1575 cm ³ ) as shown in FIG.
Nine pieces were placed in a 3 × 3 arrangement with a distance of 100 mm from each other so that the surface of the block became the upper surface (a frame was attached around the block so that the gap with the block was also opened by 100 mm). I went to do it.

In FIG. 3, reference numeral 31 denotes a pressure feed pump;
a and 32b are pressure feed pipes, 33 is a nozzle pipe, 34 is a spray nozzle, 35 is a quick-setting binder feeder, 36 is an air compressor, 37 is a mixer, 38 is a heat insulating wall,
Reference numeral 39 denotes a sprayed construction body, 40 denotes a compressed air injection port, 41 denotes a quick-setting agent injection port, and 42 and 43 denote air flow rate regulating valves. In addition, using a pressure pump BSA702 manufactured by Putzmister having two pistons as the pressure pump, the pressure speed was adjusted to 3 tons per hour with kneaded clay, and compressed air adjusted to 4 to 6 atm was injected from the compressed air inlet. The kneaded material was supplied to the spray nozzle.

Further, in order to quantitatively supply the powdery quick setting agent to the kneaded material, the air pressure was controlled within a range of 3 to 4 atm using a Q gun manufactured by Nippon Pribrico Co., Ltd. equipped with a table feeder. Was adjusted to the injection amount of the quick setting agent shown in FIG.

In the spraying apparatus used in the above embodiment, the pressure-feeding pipe 32a from the pressure-feed pump 31 to the compressed air inlet 40 was narrowed down to a steel pipe having a size of 65A and a length of 30m and a length of 65 to 50A. It is assumed that a tapered steel pipe having a length of 1 m is connected, and a pressure-feeding pipe 32b from the compressed air injection port 40 to the quick-setting agent injection port 41 has a length of 3 and a size of 50A.
m, and the nozzle pipe 33 from the quick-setting agent injection port 41 to the spray nozzle 34 has a length of 1.50A and a length of 1.
A 2 m rubber hose was connected so that there was no step inside the pipe. Further, a Y-shaped tube was attached to each of the compressed air injection port 40 and the quick setting agent injection port 41.

Since the spray nozzle 34 is connected to a flexible rubber hose, it is easy to move and change the direction within the range of the rubber hose. Installed. According to this construction method, there was no need to attach and remove the formwork required for conventional vibration construction, and the refractory furnace structure could be constructed in a very short time. Furthermore, there was almost no dust generation during spraying, and the working environment was extremely good as compared with the conventional dry spraying method for irregular shaped refractories.

[0057] One of the construction bodies integrally molded in this way is
The apparent porosity, bulk specific gravity, and compressive strength of the test pieces cut out from the joints dried at 110 ° C. for 24 hours were measured by the methods specified in JIS-R2205. The results are shown in Table 1. In addition, the integrally formed construction body is 180
Up to 20 ° C every hour, hold at 180 ° C for 20 hours, 400
Up to 20 ° C every hour, hold at 400 ° C for 15 hours, 400
Although heating and drying were performed at a temperature of 50 ° C. per hour from 800 ° C. to 800 ° C., it was confirmed that the integrity was not impaired at all and that the entire construction sufficiently functioned as a high-strength and dense furnace bottom.

The spraying construction device shown in FIG. 4 is an example of another construction device that can be used for performing spraying construction.
31 is a pressure feed pump, 32a is a pressure feed pipe, 33 is a nozzle pipe, 34 is a spray chisel, 35 is a quick-setting agent feeder, 3
6 is an air compressor, 37 is a mixer, 38 is a construction wall surface, 39 is a sprayed construction body, 44 is an inlet for compressed air and quick-setting agent, and 42 and 43 are air flow control valves. In this case, the quick-setting agent injection port and the compressed air injection port are at the same location, and the pressure feed pipe 32a and the nozzle pipe 33
, The air flow control valve 42 is fully opened,
If 43 is fully closed, it is possible to perform spraying using only the air for transferring the quick-setting agent, and it is possible to easily operate the spraying device or to use the air used for spraying the clay. It is possible to obtain excellent effects such as a reduction in the amount of used and a reduction in the amount of generated dust.

[0059]

[Table 1]

[0060]

According to the method for forming a refractory furnace structure of the present invention, it is possible to construct a refractory furnace structure in a very short time without any work of mounting and removing a formwork required in the conventional vibration construction. In addition, there was almost no generation of dust during spraying, and the working environment was extremely good as compared with the conventional dry spraying method for amorphous refractories. Further, the refractory furnace structure having a heat insulating layer obtained by the spraying construction method of the present invention, physical properties, strength is extremely dense and high strength, aluminum melting furnace, holding furnace, copper melting furnace, steel making ladle, It has physical properties sufficient to be applied to various melting and melting furnaces such as a degassing furnace and a heating furnace, and its industrial value is enormous.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view showing a typical example of a furnace structure formed by the present invention.

FIG. 2 is an explanatory view showing an example of arrangement of bricks for forming a furnace structure of the present invention.

FIG. 3 is a schematic diagram of an example of an apparatus used to form a furnace structure of the present invention.

FIG. 4 is a schematic diagram of another apparatus used to form the furnace structure of the present invention.

[Explanation of symbols]

 1: hearth section 1-1: heat-insulating castable layer 1-2: refractory castable layer 1-3: sprayed construction body 1-4: precast block 2: side wall section 3: ceiling section 31: pumping pump 32a, 32b: pumping Piping 33: Nozzle piping 34: Blowing nozzle 35: Quick binder feeder 40: Compressed air inlet 41: Quick binder inlet

Claims (6)

[Claims] An irregular refractory composition comprising a plurality of fixed refractories having a predetermined shape, spaced apart from each other, and a refractory aggregate, a refractory powder and a dispersant in a gap between the refractories. The kneaded clay having self-fluidity kneaded by adding water is pumped to the construction site by a pressure pump and a pressure pipe, and compressed from a compressed air inlet and a quick-setting agent inlet provided in a downstream portion of the pressure pipe. Air and a required amount of quick-setting agent are injected into the kneaded material, and the kneaded material mixed with the quick-setting agent together with the injected compressed air is sent to a spray nozzle connected to the tip thereof through a nozzle pipe. A method for forming a furnace structure, characterized by being sprayed and integrated with a fixed refractory. 2. The refractory according to claim 1, wherein said refractory has a surface facing the furnace.
An amorphous refractory composition which is a large-sized block having a bulk density of not less than 00 cm ² and a bulk density of 2.2 or more and an apparent porosity of not more than 15%, and which has been blown at intervals between fixed refractories, has a bulk density of 2.2. As described above, the apparent porosity is 15% or less.
A method for forming the furnace structure according to the above. 3. The method for forming a furnace structure according to claim 1, wherein an interval between said fixed refractories is 50 mm or more. 4. The quick-setting agent inlet is provided downstream of the compressed air inlet or at the same position as the compressed air inlet.
A method for forming the furnace structure according to the above. 5. The method for forming a furnace structure according to claim 1, wherein the quick-setting agent is injected using part or all of the compressed air injected into the clay. 6. A clay having self-fluidity having an upper end inner diameter of 50%.
mm, the inner diameter of the lower end is 100 mm, the height of 150 mm, and the cone immediately after kneading is filled and filled into a truncated cone-shaped cone having upper and lower ends opened, the cone is pulled out upward, and the spreading diameter when left to stand for 60 seconds is 180 mm. The method for forming a furnace structure according to claim 1, wherein the method has the above fluidity.