JP6420922B1 - Method for spraying irregular refractories and spraying materials used therefor - Google Patents

Abstract

[PROBLEMS] To provide a water injection device in a material transport pipe from a material supply machine to a tip spray nozzle, and to spray an unstructured refractory that injects construction water into the spray material transported through the material transport pipe from the water supply device. In the method, the stability of the spraying construction is improved. A water injection device is provided in a material conveyance pipe extending from a material supply machine to a tip spray nozzle, and construction water is poured into the spray material conveyed through the material conveyance pipe from the water injection device together with gas. In the method for spraying regular refractories, the spray material contains 70% by mass or more of magnesia-containing raw material, and the amount of construction water from the water injector 7 is 10% by mass or more and 50% by mass with respect to 100% by mass of the spray material. It is below mass%. [Selection] Figure 1

Description

  The present invention relates to various molten metal containers and kilns such as blast furnaces, firewood, kneading vehicles, converters, ladle, secondary smelting furnaces, tundish, cement rotary kilns, waste melting furnaces, incinerators, and non-ferrous molten metal containers. TECHNICAL FIELD The present invention relates to a method for spraying an irregular refractory during the construction or repair of steel, and a spray material used therefor.

The method of spraying irregular refractories can be broadly divided into wet construction methods and dry construction methods.
The wet construction method is a construction method in which construction water is added to a material in advance and kneaded to form a slurry-like spraying material, and a quick setting agent or the like is added and sprayed at a tip spray nozzle portion. On the other hand, the dry construction method is a construction method in which the spray material is transported by gas in a dry state, and the construction water is injected and sprayed at the tip spray nozzle portion.

  The wet construction method is capable of forming a dense refractory spray construction body having better adhesion than the dry construction method, and has the effect of reducing the amount of dust generated during construction. On the other hand, a kneading device and a slurry pumping device are required for spraying, and the structure of the device is complicated and expensive, and after spraying, slurry-like spraying material adheres to the kneading device and the conveyance hose. However, there is a drawback that it takes time for the cleaning operation.

  On the other hand, in the dry construction method, the spraying device is basically simple and workable because the construction water is simply injected into the spraying material that has been transported in a dry state by the tip spray nozzle. Although the spraying is performed in a state where water (construction water) is not sufficiently mixed with the spray material, a lot of dust is generated during spraying, and the refractory structure of the sprayed body is uneven. The adhesion rate, adhesive strength and corrosion resistance are also inferior. Compared with the wet construction method, there is also a drawback that it is difficult to obtain a dense spray construction body because the kneading effect is low and the amount of construction water is large.

Therefore, as an improvement of the dry construction method, two water injectors are provided in the material transport pipe from the material supply machine to the tip spray nozzle, and spraying that sprays atomized water with an average of 100 μm or less together with compressed air from each water injector A construction method is known (see, for example, Patent Document 1).
However, when the present inventors have carried out a large number of spraying constructions by this spraying construction method, when a spraying material mainly composed of magnesia-containing raw materials is used as the spraying material, the connection part (seamless) of the material transport pipe is used. Part) was found to be sprayed. When the spray material adheres in the material transport pipe, there arises a problem that the transportability of the spray material is deteriorated and the stability of the spraying work is lowered.

Japanese Patent No. 4377913

  The problem to be solved by the present invention is that a water injection device is provided in a material conveyance pipe from the material supply machine to the tip spray nozzle, and the construction water is injected from the water injection device into the spray material conveyed in the material conveyance pipe. In the method of spraying a regular refractory, the object is to prevent the spray material from adhering in the material transport pipe.

  In order to suppress the spraying material from adhering to the material conveying pipe, the present inventors have repeated tests with a particular focus on the construction water amount (water injection amount) from the water injector, and contain magnesia as the spraying material. In the case of using a spray material mainly composed of raw materials, it has been found that it is effective to increase the amount of construction water from the water injector to a conventional amount of construction water, and the present invention has been completed.

That is, according to one aspect of the present invention, the following spray construction method is provided.
A water injector is provided in the material transport pipe from the material feeder to the tip spray nozzle, and a kneader is not provided in the material transport pipe, and the construction water is added to the spray material transported from the water injector to the spray material transported in the material transport pipe. A method for spraying irregular refractories for water injection,
The spray material contains 70% by mass or more of magnesia-containing raw material, and the amount of construction water from the water injector is 10% by mass to 50% by mass with respect to 100% by mass of the spray material. Refractory spraying method.

Further, according to another aspect of the present invention, a spray material used in the method for spraying an irregular refractory according to the present invention, comprising 70% by mass or more of a magnesia-containing raw material, and having a particle size of 0.5 mm. There is provided a spray material in which the content of a magnesia-containing raw material of 4 mm or less is 30% by mass or more and 60% by mass or less .

  ADVANTAGE OF THE INVENTION According to this invention, in the case of spray construction, it can suppress that spray material adheres in a material conveyance pipe | tube, and the stability of spray construction improves.

The conceptual diagram which shows an example of the spraying apparatus for enforcing the spraying construction method of this invention.

  First, an example of the spray apparatus for implementing the spray construction method of this invention is demonstrated, referring FIG.

  In FIG. 1, reference numeral 1 denotes a material supply machine in which a spray material 2 is stored. As long as the material supply machine 1 is generally used in spraying devices for irregular refractories and can discharge a certain amount, any type of material such as a protector gun, a lead gun, a field cement gun, etc. can be used without any problem. it can.

  The spray material 2 in the material supply machine 1 is supplied with a material by a table feeder 3 that is driven by a motor M provided at the lower end, the internal pressure of which is adjusted by a gas such as compressed air supplied into the material supply machine 1. It is supplied to the material conveying pipe 5 from the machine 1 to the tip spray nozzle 4.

  The material conveying pipe 5 is supplied with the blowing material conveying gas through the blowing material conveying gas introduction pipe 6 of the table feeder 3, and the blowing material 2 from the material supply machine 1 is supplied to the tip of the material conveying pipe 5. 4 is sprayed onto the spray target object A.

In the material conveying pipe 5, a water injector 7 is provided in the vicinity of the tip spray nozzle 4, and a blowing means 8 is provided on the upstream side of the water injector 7.
From the water injector 7, the construction water is supplied together with the construction water transport gas to the spray material 2 transported through the material transport pipe 5. The configuration of the water injector 7 is not particularly limited as long as the construction water can be supplied (poured) into the material conveyance pipe 5 together with the construction water conveyance gas. Since the construction water is poured from the water injector 7 together with the construction water transport gas, the construction water becomes so-called spray water (atomized water).
The position where the water injector 7 is provided is preferably in the range of 0.5 m or more and less than 5 m from the tip of the tip spray nozzle 4, more preferably 0.5 m or more and less than 3 m. The length of the tip spray nozzle 4 is approximately 1 m or more and 10 m or less.

  From the blowing means 8, construction water is blown into the blowing material 2 conveyed in the material conveying pipe 5 together with the gas. The configuration of the blowing means 8 is not particularly limited, and may be the same as that of the water injector 7, for example. About the distance space | interval of this blowing means 8 and the water injection device 7, Preferably it is 15 m or more. In addition, in the spray construction method of this invention, since the blowing means 8 does not necessarily need to be used, it is omissible.

  The gas such as the blowing material conveying gas and the construction water conveying gas used in the present invention is typically air (compressed air), but other gases such as nitrogen (compressed nitrogen) should be used. You can also. Moreover, the pressure of the gas to be used can be made into the range of about 0.2 MPa or more and 0.5 MPa or less.

Next, the spraying construction method of the present invention will be described by using the spraying device of FIG.
In the spray construction method of the present invention, a spray material containing 70 mass% or more of a magnesia-containing raw material is used as the spray material. In this way, the spray material containing 70% by mass or more of the magnesia-containing raw material has the property that the magnesia-containing raw material easily adheres water, so that the function of additives such as a binder in the spray material is exhibited. Not enough water is needed.
Therefore, the present invention is characterized in that the amount of construction water supplied from the water injector 7 is 10% by mass or more and 50% by mass or less with respect to 100% by mass of the spray material.
When the amount of construction water from the water injector 7 is less than 10% by mass, it becomes a highly viscous spray material, and in particular, it tends to adhere to the connecting portion of the material transport pipe 5 near the water injector 7. On the other hand, when the amount of construction water from the water injector 7 exceeds 50% by mass, the amount of construction water becomes excessive, and the adhesion to the spray target A decreases.

  In the spray construction method of the present invention, when using a spray device provided with the blow means 8 on the upstream side of the water injector 7 as shown in FIG. 1, the construction water amount from the blow means 8 is 100 mass% of the spray material. On the other hand, it is 3% by mass or less (including 0% by mass) by the outer cover, and the total amount of construction water from the blowing means 8 and the water injector 7 is 10% by the outer cover with respect to 100% by weight of the spray material. It is preferable that they are mass% or more and 50 mass% or less. By adopting such a construction water amount balance, adhesion to the material transport pipe 5 can be reduced when the blowing means 8 is used.

  In the present invention, the content of the magnesia-containing raw material having a particle size of more than 0.5 mm and not more than 4 mm in 100% by mass of the spray material is preferably 30% by mass or more and 60% by mass or less. The magnesia-containing raw material (coarse particles) having a particle size of more than 0.5 mm and 4 mm or less exhibits an effect (hereinafter referred to as “grinding effect”) of scraping off the spray material adhering to the material conveying pipe 5. However, if the content of the magnesia-containing raw material having a particle size of more than 0.5 mm and not more than 4 mm is less than 30% by mass, this grinding effect cannot be sufficiently obtained. On the other hand, when the content of the magnesia-containing raw material having a particle size of more than 0.5 mm and not more than 4 mm exceeds 60% by mass, rebound loss is likely to occur, and adhesion to the spray target A may be reduced. In addition, although it is preferable not to contain the magnesia containing raw material with a particle size over 4 mm from the point of reducing rebound loss, if it is a small amount, you may contain it.

In the present invention, the content of the magnesia-containing raw material having a particle size of 45 μm or less in 100% by mass of the spray material is preferably 3% by mass or more and 20% by mass or less. Since the magnesia-containing raw material (fine powder) having a particle size of 45 μm or less is likely to adhere, particularly by biting into the connection portion of the material transport pipe 5, the content of the material transport pipe 5 is set to 20 mass% or less. Adhesiveness to can be further reduced. On the other hand, when the content of the magnesia-containing raw material having a particle size of 45 μm or less is less than 3% by mass, it becomes difficult to form a good spray construction body.
Here, in the present invention, the particle diameter of the particles exceeding d means that the particles remain on the sieve having an opening d, and the particle diameter of not more than d means that the particles are eyes. It means a particle size that passes through a sieve having an opening d.

In this invention, it is preferable that the flow velocity of the spray material in the water injector 7 installation position is 15 (m / s) or more and 150 (m / s) or less. Since the water injector 7 installation position is the connection part of the material transport pipe 5, the material transport pipe 5 (connection part) can be achieved by setting the flow rate of the spray material at the water injector 7 installation position to 15 (m / s) or more. Adhesiveness to can be further reduced. On the other hand, when the flow rate of the spray material exceeds 150 (m / s), rebound loss is likely to occur, and the adhesion to the spray target object A may be reduced.
The flow rate of the spray material at the position where the water injector 7 is installed is the total flow rate of the transport gas introduced into the material transport pipe 5 (Nm ³ / min) (the spray material transport from the spray material transport gas introduction pipe 6) and the use gas flow rate ^(Nm 3 / min), and the flow rate of the construction water conveying gas from the water injector 7 ^(Nm 3 / min), the gas from the blowing means 8 when using the feed means 8 flow rate ( Nm ³ / min) total flow rate (Nm ³ / min)), the pressure of these transfer gases, the opening area of the material transfer pipe 5 at the position where the water injector 7 is installed, and the like.

  In addition to the magnesia-containing raw material, the spraying material used in the spraying construction method of the present invention contains other refractory powders and additives such as binders, dispersants, and quick setting agents as appropriate. It can also contain fibers with additives.

  In the present invention, the “magnesia-containing raw material” means a magnesia (MgO) content of 40% by mass or more, and examples thereof include dolomite raw materials and olivine raw materials in addition to magnesia raw materials.

  As the refractory powder other than the magnesia-containing raw material, any refractory powder used for a general magnesia-shaped amorphous refractory can be used without any problem. For example, metal oxides, metal carbides, metal nitrides, carbons, metals, and the like, which can be appropriately selected and combined depending on the material of the object to be sprayed, temperature conditions, and the like.

  Examples of the binder include slaked lime, alumina cement, magnesia cement, phosphate, silicate, and the like, and one or more of these can be used in combination.

  The dispersant is also called a peptizer and has the effect of imparting the fluidity of the spray material. As this dispersant, any dispersant used in general amorphous refractories can be used without any problem. Specific examples include sodium tripolyphosphate, sodium hexametaphosphate, sodium ultrapolyphosphate, sodium acid hexametaphosphate, sodium borate, sodium carbonate, polymetaphosphate, silicate, phosphate and other inorganic salts, sodium citrate, Examples thereof include sodium tartrate, sodium polyacrylate, sodium sulfonate, polycarboxylate, β-naphthalenesulfonate, naphthalene sulfonic acid, carboxyl group-containing polyether dispersant, and the like.

The rapid setting agent reacts with the binder in the presence of construction water to rapidly cure the spray material and impart adhesion to the spray material. The quick setting agent may be mixed in the spray material from the beginning in a powder state, or the quick setting agent may be added from the tip spray nozzle 4 or the water injector 7. When the quick setting agent is added from the tip spray nozzle 4 or the water injector 7, the quick setting agent is used in a liquid form diluted with water as necessary.
Specific examples of the quick setting agent include silicates such as sodium silicate and potassium silicate, aluminates such as sodium aluminate, potassium aluminate and calcium aluminate, sodium carbonate, potassium carbonate and sodium hydrogen carbonate. carbonates, sodium sulfate, potassium sulfate, sulfates such as 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 Calcium aluminates such as ₃ · CaF ₂ , 11CaO · 7Al ₂ O ₃ · CaF ₂ , calcium salts such as calcium oxide, calcium hydroxide, and calcium chloride.

  As the fiber, a fiber that is an ordinary amorphous refractory and used for the purpose of preventing explosion or the like can be used, and examples thereof include vinylon, nylon, PVA, polyvinyl, polystyrene, polypropylene, and carbon.

  The spray construction method of the present invention can be carried out under any temperature condition between cold, warm and hot. And the material structure of the spraying material used for the spraying construction method of this invention can be suitably determined according to these temperature conditions, the material of the spraying object, etc.

Table 1 shows examples and comparative examples of the present invention.
The spray material is magnesia powder as a magnesia-containing raw material. In Table 1, “Others”, siliceous powder and carbonaceous powder as refractory powders other than the magnesia-containing raw material, slaked lime as a binder, and silicate as a dispersant. It is assumed that phosphate is mixed at a predetermined ratio, and this spraying material is sprayed by the spraying device of FIG. 1, and adherence in the material transport pipe 5 (hereinafter referred to as “adhesion of transport pipe”). The adhesion (hereinafter referred to as “adhesion of the target object”) to the spray target object A (chamot brick) was evaluated. And comprehensive evaluation was performed based on these evaluation results.
The pressure of the construction water transport gas, the spray material transport gas, and the gas blown from the blowing means 8 was in the range of 0.2 MPa to 0.5 MPa.
In Table 1, the “flow velocity (m / s) of spray material” is the flow velocity (m / s) of the spray material at the installation position of the water injector 7 in FIG. 1, and both are calculated values. .

  Regarding the adhesion of the transport pipe, after spraying 100 kg of the spray material, the state of adhesion of the spray material at the connecting portion of the material transport pipe 5 (near the water injector 7) was visually confirmed. Specifically, the case where the adhesion of the spray material is less than 5% of the cross-sectional area of the connecting portion of the material conveying pipe 5 is excellent (excellent), and the case where it is 5% or more of the cross-sectional area of the connecting portion is less than 10% is good (good). The case where the cross-sectional area of the connecting portion is 10% or more was evaluated as x (defect).

  The adherence of the target object was evaluated by the ratio of the spray material adhered to the spray target object A (chamotte brick) after spraying 100 kg of the spray material. Specifically, ◯ (excellent) when the spraying material adhesion ratio is 80% by mass or more, △ (good) when 60% by mass or more and less than 80% by mass, and × (impossible) when less than 60% by mass. ).

Comprehensive evaluation was evaluated in the following three stages based on the evaluation results of the adhesion of the transport pipe and the adhesion of the object.
○ (excellent): Both evaluation results are ○ (excellent).
Δ (good): At least one of the evaluation results is Δ (good), and there is no evaluation result of × (bad).
X (defect): At least one evaluation result is x (defect).

In each of Examples 1 to 13 in Table 1, the spray material contains 70% by mass or more of the magnesia-containing raw material, and the construction water amount from the water injector 7 is 10% by mass with respect to 100% by mass of the spray material. Above 50% by mass and within the scope of the present invention, the adherence of the transfer tube and the adherence of the object were good without evaluation of x (defect), and the overall evaluation was also good.
In addition, Examples 14 and 15 in Table 1 are examples in which spraying was performed using the blowing means 8 in the spraying device of FIG. Specifically, Example 14 is an example in which construction water is blown from the blowing means 8 together with gas (construction water carrying gas), and Example 15 is an example in which only the gas is blown from the blowing means 8. In any case, the spray material contains 70% by mass or more of the magnesia-containing raw material, and the construction water amount balance from the water injector 7 and the blowing means 8 is also within the scope of the present invention. Was good without evaluation of x (defect), and the overall evaluation was also good.

On the other hand, Comparative Example 1 is an example in which the amount of construction water from the water injector 7 is as small as 5% by mass. The evaluations of the adhesion of the transfer tube and the adhesion of the object were x (defect).
The comparative example 2 is an example with much construction water amount from the water injector 7 as 60 mass%. The evaluation of the adhesion of the object was x (defect).

DESCRIPTION OF SYMBOLS 1 Material supply machine 2 Spraying material 3 Table feeder 4 Tip spray nozzle 5 Material conveyance pipe 6 Spraying material conveyance gas introduction pipe 7 Water injection device 8 Blowing means A Spray object

Claims (7)

A water injector is provided in the material transport pipe from the material feeder to the tip spray nozzle, and a kneader is not provided in the material transport pipe, and the construction water is added to the spray material transported from the water injector to the spray material transported in the material transport pipe. A method for spraying irregular refractories for water injection,
The spray material contains 70% by mass or more of magnesia-containing raw material, and the amount of construction water from the water injector is 10% by mass to 50% by mass with respect to 100% by mass of the spray material. Refractory spraying method. A blowing means for blowing construction water together with gas or gas into the blowing material is provided on the upstream side of the water injector,
The amount of construction water from the blowing means is 3% by mass or less (including 0% by mass) with respect to 100% by mass of the spray material, and the amount of construction water from the blowing means and the water injector is 2. The method for spraying an amorphous refractory according to claim 1, wherein the total amount is 10% by mass or more and 50% by mass or less as an outer shell with respect to 100% by mass of the spray material. The content of the particle size 0.5mm ultra 4mm or less magnesia containing raw material in spraying material 100 mass% is 60 mass% or less than 30 mass%, blowing of the monolithic refractory of claim 1 or 2 with construction methods. The content of the particle size 45μm or less magnesia containing raw material in spraying material 100 mass% is 20 mass% or less 3% by mass or more, blowing a monolithic refractory according to any of claims 1 3 Construction method. The spray construction method of the irregular-shaped refractory according to any one of claims 1 to 4, wherein a flow rate of the spray material at the water injector installation position is 15 (m / s) or more and 150 (m / s) or less. It is a spraying material used for the spraying construction method of the irregular refractory according to any one of claims 1 to 5, containing 70 mass% or more of a magnesia-containing raw material, and having a particle size of more than 0.5 mm and less than 4 mm. The spraying material whose content of a magnesia containing raw material is 30 to 60 mass% . The spraying material of Claim 6 whose content of the magnesia containing raw material of a particle size of 45 micrometers or less is 3 mass% or more and 20 mass% or less.

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