JP6420921B1 - 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 from a material supply machine to a tip spray nozzle, and the construction water is injected into the spray material conveyed in the material conveyance pipe from the water injection device. In the method of spraying construction material, the flow rate (Nm3 / min) of the construction water carrying gas for carrying the construction water introduced into the water injector 7 and the blowing material carrying gas for carrying the spraying material The ratio of the flow rate (Nm3 / min) to the flow rate (flow rate of construction water transfer gas / flow rate of spray material transfer gas) is 0.07 or more and 2 or less, and particles having a particle size of 45 μm or less in the spray material The content of is 3% by mass or more and 30% by mass or less. [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 carried out a lot of spraying construction by this spraying construction method, the discharge amount of the spraying material fluctuates or a phenomenon that the spraying material and the construction water are separated is occasionally seen. It was found that there was room for improvement in the stability of spray construction. Further, when the inside of the material transport pipe was observed after the spray construction, which had a problem with the stability of the spray construction, adhesion of the spray material was observed particularly at the connection part (seam part) of the material transport pipe.

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 regular refractories, the stability of the spraying construction is to be improved.

In order to improve the stability of the spraying construction, the present inventors improve the water mixing of the construction water to the spraying material and the transportability of the spraying material and reduce the adhesion of the spraying material in the material transport pipe. As a result of repeated tests, the flow rate of the construction water transport gas (Nm ³ / min) for transporting the construction water introduced into the water injector and the spray material for transporting the spray material The ratio of the flow rate of the transport gas (Nm ³ / min) and the content of particles having a particle size of 45 μm or less in the spray material improve the above-mentioned water mixing and transportability, and the spray material in the material transport pipe It has been found that this is an important parameter for lowering the adhesion of the resin and thus improving the stability of the spraying construction, and the present invention has been completed.

That is, according to one aspect of the present invention, the following spray construction method is provided.
This is a spraying method for irregular refractories in which a water injector is installed in the material transport pipe from the material supply machine to the tip spray nozzle, and the construction water is injected into the spray material transported through the material transport pipe from this water injector. And
The flow rate of the construction water carrier gas for transporting the construction water introduced into the water injector and (Nm 3 / ^min), the spraying material conveying gas for conveying the spraying material flow (Nm 3 ^/ min ) (Flow rate of construction water carrying gas / flow rate of blowing material carrying gas) is 0.07 or more and 2 or less, and the flow rate of construction water carrying gas (Nm ³ / min) and the amount of construction water ( m ³ / min) (flow rate of construction water carrying gas / volume of construction water) is 100 or more and 1000 or less, and the content of particles having a particle size of 45 μm or less in the spray material is 3% by mass or more. A method for spraying an irregular refractory that is 30% by mass or less.

Moreover, according to the other viewpoint of this invention, it is a spraying material used for the spray construction method of the amorphous refractory of this invention, Comprising: Content of the particle | grains with a particle size of 45 micrometers or less is 3 to 30 mass%. % Ri der less, spraying material compression degree is less 32% is provided.

  According to the present invention, during the spraying construction, the mixing water of the construction water with respect to the spraying material and the transportability of the spraying material are improved, and the adhesion of the spraying material in the material transport pipe is lowered. Improves the stability of installation.

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.
The first feature of the spray construction method of the present invention is that the flow rate (Nm ³ / min) of the construction water transport gas for transporting the construction water introduced into the water injector 7 and the spray material are transported. The ratio of the flow rate of the spray material conveying gas (Nm ³ / min) (the flow rate of the construction water transfer gas / the flow rate of the spray material transfer gas) (hereinafter referred to as the “transport gas flow ratio”) is 0. 0.07 or more and 2 or less. By making this conveyance gas flow rate ratio 0.07 or more and 2 or less, the mixing water of construction water and the transportability of the spraying material are improved, and the stability of the spraying construction is improved.
On the other hand, if the transport gas flow ratio is less than 0.07, the flow rate of the spray material transport gas is large, so the construction water does not reach the center of the material transport pipe 5 that transports the spray material, Water mixing becomes worse.
On the other hand, if the transfer gas flow ratio exceeds 2, the flow rate of the construction water transfer gas is large, so that a turbulent flow occurs with the spray material transfer gas, and as a result, spraying in the vicinity of the water injector 7 The adhesion of the material and, further, the adhesion of the spray material also occurs on the material transport pipe 5 on the upstream side thereof, and the transportability of the spray material is deteriorated.
The transfer gas flow rate ratio is preferably 0.1 or more and 1 or less.

The second feature of the spray construction method of the present invention is that a spray material having a content of particles having a particle size of 45 μm or less of 3% by mass to 30% by mass is used. By using the spray material having such a particle size structure, it is possible to reduce the adhesion of the spray material particularly at the connection portion of the material transport pipe 5 such as in the vicinity of the water injector 7.
On the other hand, when the content of particles having a particle diameter of 45 μm or less exceeds 30% by mass, particles (fine powder) having a particle diameter of 45 μm or less are particularly caught in the connection part of the material transport pipe 5 and blown to the connection part. Adhesive material is likely to adhere. As a result, the transportability of the spray material is reduced.
On the other hand, when the content of particles having a particle size of 45 μm or less is less than 3% by mass, it becomes difficult to form a good sprayed construction.
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 the spray construction method of the present invention, it is preferable to use a spray material having a compressibility of 32% or less. In other words, it is preferable to use a spray material whose particle size configuration is adjusted so that the degree of compression is 32% or less. Here, the degree of compression is obtained by the following equation.
Compressibility (%) = (Densely packed bulk density−Roughly packed bulk density) / Densely packed bulk density × 100
In addition, although mentioned later for details, the spraying material used by this invention may contain a fiber in addition to a refractory raw material powder, When a fiber is contained, evaluation of a compressibility (dense filling bulk density and loose filling) The measurement of the bulk density is carried out in a state where the fibers are removed. That is, when a spray material contains a fiber, the compression degree said by this invention means what evaluated about the spray material except a fiber.
By using a spraying material having a degree of compression of 32% or less, the water content of the construction water and the transportability of the spraying material are improved, and the stability of the spraying work is improved. This degree of compression is preferably 25% or less.
In addition, the above-mentioned particle size constitution (content of particles having a particle size of 45 μm or less is 3% by mass or more and 30% by mass or less) is also preferable from the viewpoint that the compressibility of the spray material is easily set to 32% or less.

In the spray construction method of the present invention, the ratio of the flow rate (Nm ³ / min) of the construction water carrying gas to the construction water volume (m ³ / min) (the flow rate of the construction water carrying gas / the construction water volume) (hereinafter “gas” -It is preferable to set it as 100 or more and 1000 or less. By setting the gas / construction water amount ratio to 100 or more and 1000 or less, the water content of the construction water, the transportability of the spray material, and the stability of the spray construction are improved. The gas / construction water amount ratio is preferably 250 or more and 800 or less.

  In the spraying construction method of the present invention, when using a spraying device provided with blowing means 8 on the upstream side of the water injector 7 as shown in FIG. 1, the construction water volume from the blowing means 8 is 20% by mass of the total construction water volume. It is preferable to pour the remaining construction water of the total construction water amount from the water injector 7 (including 0% by mass) below. By using such a construction water injection amount balance, when using the blowing means 8, the mixed water of the construction water, the transportability of the spraying material, and the stability of the spraying construction are improved.

Here, when the construction water is blown from the blowing means 8 together with the gas or the gas, the flow rate (Nm ³ / min) of the gas blown from the blowing means 8 is the calculation of the above-mentioned transfer gas flow rate ratio and gas / construction water amount ratio. In this case, it is added as “flow rate of construction water transport gas (Nm ³ / min)”.
Similarly, the construction water amount (Nm ³ / min) from the blowing means 8 is added as “construction water amount (m ³ / min)” in the above-described calculation of the gas / construction water amount ratio.

In the spray construction method of the present invention, the ratio of the discharge amount of spray material (kg / min) to the total flow rate of transport gas (Nm ³ / min) (discharge amount of spray material / total flow rate of transport gas) ) (Hereinafter referred to as “solid-gas ratio”) is preferably 1 or more and 20 or less. By setting this solid-gas ratio to 1 or more and 20 or less, the mixed water of the construction water, the transportability of the spray material, and the stability of the spray construction are improved.
Note that "total flow rate of carrier gas (Nm 3 / ^min)" used in this solid-gas ratio calculation, the spraying material conveying gas from spraying material carrier gas introduction pipe 6 a flow rate (Nm ³ / min), the flow rate of the construction water transfer gas from the water injector 7 (Nm ³ / min), and the total flow rate of the gas flow rate (Nm ³ / min) from the blowing means 8 when the blowing means 8 is used. It means (Nm ³ / min).

  The spraying material used in the spraying construction method of the present invention can be appropriately mixed and mixed with additives such as a binder, a dispersing agent and a quick setting agent in addition to the refractory powder. A fiber can also be contained with an agent.

  As the refractory powder, any refractory powder used for general amorphous refractories 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.

<First embodiment>
Table 1 shows a first embodiment of the present invention. In this example, spraying was performed without using the blowing means 8 in the spraying device of FIG. That is, in this example, construction water and construction water transport gas were supplied only from the water injector 7. The pressure of the construction water carrying gas and the spray material carrying gas was in the range of 0.2 MPa to 0.5 MPa.
The spray material is a mixture of alumina-siliceous powder as a refractory powder, slaked lime as a binder, and silicate as a dispersant in a predetermined ratio. Spraying, evaluating water mixing and transportability at that time, adhesion in the material transport pipe 5 (hereinafter referred to as "adhesion of the transport pipe") and adhesion to the spray object A (chamotte brick) ( Hereinafter, “adhesiveness of the object” was evaluated. And comprehensive evaluation was performed based on these evaluation results.

  The mixed water was evaluated by visually observing the state of spraying from the tip spray nozzle 4 and by the degree of separation between the construction water and the spray material. The smaller the degree of separation, the better the water mixing. Specifically, the case where there was no separation was evaluated as ◯ (excellent), the case where separation was small was evaluated as Δ (good), and the case where separation was large was evaluated as x (defective).

  The transportability was evaluated by visually observing the state of spraying from the tip spray nozzle 4 and by the degree of variation in the discharge amount of the spray material. The smaller the variation in the discharge amount, the better the transportability. Specifically, the case where there was no change in the discharge amount was indicated as ◯ (excellent), the case where there was a slight change in the discharge amount, Δ (good), and the case where the change in the discharge amount was large was indicated as x (defect).

  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, in each of the above evaluations, if all are ○ (excellent), ○ (excellent), if there is △ (good) and there is no (bad) △ (good), either × The case where there was (defect) was defined as x (defect).

  In Examples 1 to 13 in Table 1, the carrier gas flow rate ratio is 0.07 or more and 2 or less, and the content of particles having a particle size of 45 μm or less in the spray material is 3% by mass or more and 30% by mass or less. Within the scope of the present invention, in each evaluation, there was no evaluation of x (defect) and it was good, and the overall evaluation was also good.

<Second Example>
Table 2 shows a second embodiment of the present invention. In this example, spraying was performed using the blowing means 8 in the spraying device of FIG. The pressure of the construction water transporting gas, the spraying material transporting gas, and the gas blown from the blowing means 8 was in the same range as 0.2 MPa to 0.5 MPa as in the first embodiment.
The material for spraying was the same as that in the first example, and the evaluation method for each evaluation item and the criteria for comprehensive evaluation were the same as those in the first example.

  In Table 2, Example 14 is an example in which construction water is blown from the blowing means 8 together with gas (gas for carrying construction water), and Example 15 is an example in which only gas is blown from the blowing means 8. In any case, the transfer gas flow rate ratio is 0.07 or more and 2 or less, and the content of particles having a particle size of 45 μm or less in the spray material is 3% by mass or more and 30% by mass or less within the scope of the present invention. In the evaluation, x (defect) was not good, and the overall evaluation was good.

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 (4)

This is a spraying method for irregular refractories in which a water injector is installed in the material transport pipe from the material supply machine to the tip spray nozzle, and the construction water is injected into the spray material transported through the material transport pipe from this water injector. And
The flow rate of the construction water carrier gas for transporting the construction water introduced into the water injector and (Nm 3 / ^min), the spraying material conveying gas for conveying the spraying material flow (Nm 3 ^/ min ) (Flow rate of construction water carrying gas / flow rate of blowing material carrying gas) is 0.07 or more and 2 or less, and the flow rate of construction water carrying gas (Nm ³ / min) and the amount of construction water ( m ³ / min) (flow rate of construction water carrying gas / volume of construction water) is 100 or more and 1000 or less, and the content of particles having a particle size of 45 μm or less in the spray material is 3% by mass or more. A method for spraying an irregular refractory that is 30% by mass or less. 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 working amount of water from the feed means is (. Including 0 mass%) 20 mass% of the total construction water, and to water injection the remaining construction water of the total construction water from the water injector, according to claim 1 A spraying method for non-standard refractories. The ratio (discharge amount of spray material / total flow of transport gas) of the discharge amount of spray material (kg / min) and the total flow rate of transport gas (Nm ³ / min) is 1 or more and 20 or less. A method for spraying an irregular refractory according to claim 1 or 2 . It is a spray material used for the spray construction method of the irregular refractory according to any one of claims 1 to 3 , wherein the content of particles having a particle size of 45 µm or less is 3 mass% or more and 30 mass% or less. A spray material having a compressibility of 32% or less .

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