JPH05106972A - Spraying and building method of structure - Google Patents

Abstract

(57) [Summary] [Objective] When the first refractory material and the second refractory material suitable for the slag line and molten metal part of a ladle, etc. are sprayed, the thermal expansion of each refractory material Cracks tended to occur at the joints due to differences in the rate, etc., and hot water or slag was inserted from there, shortening the service life. [Composition] While continuously reducing the spraying flow rate of the first refractory material at the joint portion, the spraying flow rate of the second refractory material is continuously increased accordingly, and the first and second refractory materials are continuously increased. A layer having a continuously changing composition was interposed therebetween.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of spray construction of a structure using a refractory material or the like.

[0002]

2. Description of the Related Art A method of constructing a structure by spraying a refractory material or the like has been widely put into practical use at present. In spraying, the spraying material is pressure-fed with a carrier gas, and is sprayed from the tip of the nozzle onto the iron skin of the furnace or refining vessel to be sprayed or the surface of the refractory material. Then, there is an advantage that a uniform integrated structure can be obtained relatively easily.

Further, in the case of the lining of the refining vessel, it is necessary to line up with a plurality of types of refractory materials for each target part depending on the cause of damage and the degree thereof, so that different kinds of spray materials are stored at the same time, A method of instantly switching the material brands as needed to perform construction "Refractory 35 [6] 341-342.
(1983) "or a method of simultaneously spraying the same or different materials from different nozzles to different parts" Refractory 37 [4] 207- "
210 (1985) "is known.

Further, in Japanese Utility Model Laid-Open No. 60-69994, a multi-tank spraying machine is used to store different kinds of spraying materials in each tank, and different kinds of spraying materials are used depending on the parts to be sprayed. There has been disclosed a technique of spraying or spraying a mixture of different types of spraying materials at a constant ratio (that is, a different type of spraying material different from the stored material). Further, Japanese Patent Laid-Open No. 57-166491 discloses a solid repair by gradually changing the mixing ratio of the refractory powder and the carbonaceous solid fuel powder of the spray repair material stepwise according to the temperature of the refractory lining to be repaired. A technique for improving the durability and improving the durability is disclosed.

[0005]

However, the above-mentioned first three methods have no problem when spraying the separated parts of the structure with different materials, but the adjacent parts of the structure are formed with different materials. When installing or when applying different spray materials in the thickness direction of the spray layer of the structure, heating and cooling are repeated or sprayed like a batch type metal refining furnace or metal molten metal container. There is a problem that the structure lacks stability under use conditions where there is a concern that slag or molten metal may enter the layer. In other words, when different materials are blown separately, the thermal behaviors such as thermal expansion characteristics generally differ between the materials, so cracks occur at the boundary between different materials, which causes slag, molten metal, etc. Intrusion is likely to occur, and as a result, sufficient durability as a structure cannot be expected.

Further, as in the latter method disclosed in Japanese Patent Laid-Open No. 57-166491, the one in which the mixing ratio of the raw material of the spraying material is changed stepwise is prepared and the composition of the spraying material is changed stepwise. However, in order to improve the effect, it is necessary to prepare and store many kinds of spraying materials with various compositions. Is complicated and expensive.

The present invention solves the above problems of the prior art,
Spraying a structure that allows you to use multiple types of materials separately for each part or in the spray thickness direction according to the usage conditions of the target structure, while showing the original merit of the spraying method to obtain a homogeneous and integrated structure. The purpose is to provide a construction method.

[0008]

DISCLOSURE OF THE INVENTION The present invention is a method for constructing a structure by spraying a refractory material by first spraying a predetermined amount of the first refractory material and then spraying the first refractory material. While continuously reducing the flow rate, the spraying flow rate of the second refractory material of a different type is continuously increased accordingly, and a layer in which the mixing ratio of different refractory materials continuously changes is interposed, Finally, a method for spraying and constructing a structure, characterized in that only a predetermined amount of the second refractory material is sprayed, and a layer in which the mixing ratio of different refractory materials continuously changes is formed into a thickness of the structure. It may be interposed in the direction or along the operating surface.

[0009]

[Operation] According to the present invention, when a certain kind of the first material and another kind of the second material are divided and sprayed according to the site of the structure, the boundary caused by the difference of the materials is generated. It is possible to suppress the deterioration of durability of the built body caused by the occurrence of cracks in the part and the invasion of foreign components such as slag and molten metal into the built body due to the cracks.

That is, the cracks described above are caused by the difference in the type of spraying material to be sprayed.
According to the invention, while spraying a certain first material,
At the same time, the second material, which is a different material, is sprayed, the spraying flow rate is continuously changed, and the spraying amount is continuously changed from the first material to the second material. Since the method is adopted, the compositional composition of the sprayed amount is continuously changed in the adjacent portion of the structure whose material is to be changed, thereby suppressing the above-mentioned crack initiation, and as a result, the thermal change is chemically changed. It is possible to obtain an integrated sprayed construction structure that is also strong against corrosion resistance.

As the spraying device, various spraying devices such as one having two spraying nozzles or one spraying nozzle for continuously mixing and adjusting the refractory material in the middle thereof can be adopted.

[0012]

【Example】

Example 1 FIG. 1 is a perspective view when a part of a furnace inner wall of a billet heating furnace is cut and taken out. In this case, an example is shown in which the type of spray material is changed in the lining thickness direction.

When the refractory heat-insulating castable (the content of Al ₂ O ₃ is 38%) 2 which is the first refractory material sprayed on the iron shell 1 reaches a predetermined thickness t ₁ 100 mm, the first refractory material While continuing spraying, spraying of the second refractory material, high alumina refractory castable (Al ₂ O ₃ content 78%) was started,
Refractory Insulation Castable (Al ₂ O ₃ content 38
%) Spraying flow rate is continuously reduced while the second refractory material is high alumina refractory castable (Al ₂ O ₃ content)
Continuously increasing the spraying flow rate of the
_{When 2} = 50 mm, only the second refractory material is used, and then the second refractory material, high alumina refractory castable (Al ₂ O ₃ content 78%) 3, is sprayed as prescribed. The process was repeated until the thickness t ₃ = 200 mm.

On the other hand, as a conventional example, the fireproof heat-insulating castable (Al ₂ O ₃ content 38%) 2 which is the first refractory material in the iron shell 1 2
The _{(t 1 + t 2/2} ) that is those with 125mm spray,
Further providing a second high-alumina refractory castable (Al ₂ O ₃ content of 78%) which is a refractory material 3 (t _2/2 + t ₃₎ That 225mm sprayed furnace. When these furnace lives were compared under almost the same operating conditions, cracks occurred between layers in the thickness direction in the latter (conventional example) and protrusion of the furnace wall was observed, but cracks in the former (Example 1) were observed. No abnormalities were found in the former furnace life until repair / reconstruction.
It was possible to extend it to 1.7 times.

Embodiment 2 FIG. 2 is a perspective view when a part of the inner wall of the ladle is cut out and taken out. In this case, an example in which the type of spray material is changed along the operating surface of the lining is shown. A brick 5 with permanent tension is pre-installed on the iron skin 1. In the ladle, there are a general wall portion 6 mainly in contact with molten steel and a slag line portion 7 mainly in contact with slag, but in general, the slag line portion 7 is greatly worn out of the refractory material. Therefore, it is necessary to line the slag line portion 7 with a refractory material having high slag erosion resistance, and the upper and lower materials are widely spread.

In the case of the present invention, first, the height from the bottom of the pan is h ₁ = 2,
High-alumina spray material that is the first spray material up to 800 mm
(Al ₂ O ₃ content 93%) 2 At the time of spraying, while continuing the spraying of the first material, the second refractory material zircon-based spray material (ZrO ₂ content 48%) Starting the spraying, continuously reducing the spraying flow rate of the high-alumina spraying material, which is the first spraying material, while continuously reducing the spraying flow rate of the zircon-based spray material, which is the second refractory material. When the predetermined height h ₂ = 80 mm is reached, only the second refractory material is used, and the second refractory material, the zircon sprayed material 3, is sprayed to the predetermined height. It was performed so that h ₃ = 400 mm.

On the other hand, as a conventional example, a high-alumina spraying material (Al ₂ O ₃ content of 93%), which is the first refractory material, is used as (h ₁ + h).
_2/2) that is those sprayed to a height of 2,840mm, a further second refractory material zircon Coatings of (ZrO ₂ content _{48%) (h 2/2} + h 3) that is, the height of 440mm I prepared a ladle sprayed on. Comparing the life of these ladles under almost the same operating conditions, the life of the former is 1.3
It was double.

[0018]

INDUSTRIAL APPLICABILITY The present invention is a method for constructing a structure by spraying, in which the spraying flow rates of two kinds of spraying materials are successively changed between adjacent parts to continuously change the spraying material. By doing so, it became possible to continuously change the material composition and structure of the spray boundary layer. This ensures the formation of the jointless integral structure, which is the original feature of the spraying method, while preventing the occurrence of cracks and slag, intrusion of molten metal, etc. due to the material change of each part, and the stability as a construction body. Increased durability.

[Brief description of drawings]

FIG. 1 is a perspective view showing a construction example of changing a spray material in a lining thickness direction of the present invention.

FIG. 2 is a perspective view showing a construction example of changing a spraying material on an operating surface portion of the present invention.

[Explanation of symbols]

 1 Iron skin 2 1st spraying material 3 2nd spraying material 4 Continuous boundary layer 5 Permanent tension 6 General wall 7 Slag line

Claims (3)

[Claims] 1. A method for spraying and constructing a structure using a refractory material, in which a predetermined amount of the first refractory material is first sprayed, and then the spray flow rate of the first refractory material is continuously reduced. In accordance therewith, the spraying flow rate of the second refractory material of a different type is continuously increased, and a layer in which the mixing ratio of the different refractory materials continuously changes is interposed, and finally the second refractory material is added. A method for spraying and constructing a structure, which comprises spraying only a predetermined amount. 2. The method for spraying and constructing a structure according to claim 1, wherein a layer in which the mixing ratio of different kinds of refractory materials continuously changes is interposed in the thickness direction of the structure. 3. The method for constructing by spraying construction of a structure according to claim 1, wherein a layer in which the kind of the refractory material continuously changes is interposed along the working surface of the structure.