TW201402250A - Air-current transport spray application method for unshaped refractories - Google Patents

Abstract

Provided is an air-current transport spray application method for an unshaped refractory capable of solving the difficulty of storing an unshaped refractory containing a set-accelerating agent and of managing storage, and preventing the degradation of properties, while maintaining a simple device structure. An air-current transport spray application method for an unshaped refractory in which, immediately before air-current transport, a powdered set-accelerating agent (21) is added to an unshaped refractory material (20) containing a fire-resistant aggregate, a fire-resistant powder, a binding agent, and a dispersing agent, and the components are mixed to make an unshaped fire-resistant composition (22). While the unshaped fire-resistant composition (22) is caused to be suspended inside a transport pipe (3) on air currents in powder form, application water is added inside the transport pipe (3), and then the composition is sprayed onto a application wall surface (23) through a spray nozzle (6).

Description

Airflow transport spraying construction method for monolithic refractory Field of invention

The present invention relates to an air transport type spray coating construction method for an amorphous refractory, and more particularly to an air flow transport type capable of suppressing the change of the characteristics of the amorphous refractory material and stably performing the spray construction of the amorphous refractory material by simple operation. Spray construction method.

Background of the invention

It is known that there is a spray application method as a powerful construction method for an indeterminate refractory. Compared with the leaching method, the construction method does not require a slab for casting, and can be easily applied to a complicated shape and difficult to frame. Therefore, it has been widely used in most fields in recent years. The spraying construction method is roughly classified into a wet spraying construction method of a pump pressure feeding method and a dry spraying construction method of an air pressure feeding method.

The wet spraying construction method is a construction method in which a refractory composition for spraying and a construction water are sprayed into a mixed chain called "bad soil" which has been sufficiently mixed in advance. This bad soil is mixed with a mixer until the fluid flow rate (JIS cone use) that can be pumped is about 200 mm, and is supplied to a pressure feed pump and transported into the transfer pipe. Then, a quick-setting admixture for agglomerating the bad soil is added to the nozzle portion, and compressed air is supplied thereto, thereby spraying the construction object. It is coated so that it can be agglomerated in an instant to construct a refractory such as a furnace wall.

In the wet spray application method, a refractory having uniform quality and excellent physical properties can be obtained. However, as described above, a procedure for supplying a spray material to a pressure feed pump requires a mixer to mix the spray materials until sufficient fluidity occurs. So far, a large mixer and most people are needed. It is also difficult to manage the amount of mixed-chain water that is suitable for the flowability of the pump for pumping. For example, if the fluidity is small, it may cause clogging in the pump or in the transport tube. When the mixed chain water is excessively added to increase the fluidity, the fine refractory aggregate and the fine powder refractory powder contained in the refractory material for spraying are separated and the material cannot be transported. As mentioned above, the wet spraying construction method has many unstable factors during on-site construction.

In addition, due to the large viscosity of the bad soil, a large pump is required for long-distance transportation of the mixed-chain bad soil by pumping, and the transportation distance is shorter than that of the dry spraying construction method, at a horizontal distance. Up to about 100m. In addition, in the wet spraying construction method using a pump, the mixed-chain bad soil remains in the conveying pipe at the end of the construction, so there is also a problem of a large amount of material loss and a large number of personnel and time for taking out or cleaning.

On the other hand, the dry spraying method is a method of supplying a refractory material such as alumina cement which is hardened by bonding with water, and a refractory powder containing a refractory powder such as clay for good adhesion during spraying. The sprayer to the air pressure feed method is performed by performing air pressure feed in the transport piping. The refractory material for powder coating is added to the refractory material for powder coating by the spray nozzle portion, and the refractory composition for powder coating is contained in the nozzle to be in a highly viscous adhering state, and is ejected through the nozzle to adhere thereto. The object to be constructed is hardened to build a refractory.

Since the dry spraying method is a method in which the refractory composition for spraying is air-fed in a powder form, it does not cause clogging of the conveying pipe, and it is easy to transport and can be transported over a long distance. Therefore, the method has the advantages of being constructed at a distance or a high distance in a state where the refractory composition for spraying or spraying is placed on the ground, and is applicable to construction at various job sites.

On the other hand, in the dry spraying method, the powdery amorphous refractory composition and the construction water are mixed in the nozzle to form a viscous adhering state, so that the contact time of the refractory composition and the construction water is short. Moreover, once the amount of the refractory composition that is sent by the air is not constant, it is necessary to change the amount of the added construction water, and the construction water may be adjusted if the amount of water of the operator is not adjusted and the amount of construction water is also uneven. If the predetermined amount is not reached or the mixing is not sufficiently uniform, the quality of the refractory wall to be constructed is not uniform, and it is difficult to obtain a high-quality refractory having high strength and stability.

In response to this, a gas flow type spray coating method was developed (hereinafter, in order to distinguish it from the dry spray application method, the construction method is referred to as an air flow type spray coating method), and the air flow type spray coating method is used even in a wet type. The materials and quick-setting admixtures used in the spray application method do not need to be formed into a bad soil by a mixer in advance, that is, the material air is transported to the vicinity of the nozzle in the state of the powder, and the construction water is added from the nozzle on the upstream side, and then directly transported and Sprayed to the construction object to make it condense in a short time to construct the refractory.

In the air transport type spray coating method, the powder material and the construction water are mixed in the transport pipe after the water is added, so that a large mixer, a pressure feed pump, and most people are not required. Moreover, since the transport pipe is transported by powder, it is also possible to carry out construction at a long distance or at a high place.

In the airflow transport coating method, there are two types of differences in the manner of addition of the quick-setting admixture: the external addition method (for example, refer to Patent Documents 1 and 2), and the air is directly supplied to the upstream of the nozzle. In addition, a quick-setting agent is added in the vicinity of the nozzle, and an internal addition method (for example, refer to Patent Document 3), and a powder quick-setting agent is added and mixed in advance at the time of manufacture of the amorphous refractory composition.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent Laid-Open No. Hei 10-316478

Patent Document 2: Japanese Laid-Open Patent Publication No. 2000-356475

Patent Document 3: Japanese Laid-Open Patent Publication No. 2002-213880

Summary of invention

In the above airflow type spray coating construction method, the external addition method must transport the powder quick-setting agent to the vicinity of the nozzle, and the powder quick-setting agent must be added at a pressure higher than the pressure in the conveying pipe in the positive air pressure feeding. Press to add. Therefore, a quick-setting agent supply device, a quick-setting agent delivery pipe, a quick-setting agent addition portion, and the like are required, and the device configuration is also complicated, and in particular, a special device capable of supplying a quick-setting admixture under high pressure is required. Further, as described above, since the addition position of the powder quick-setting admixture is in the vicinity of the nozzle, the constructor who operates the nozzle on the construction object, in addition to the construction water transfer pipe and the addition portion, is chased by the accelerator tube and added. Department, the workload is significantly increased.

On the other hand, in the internal addition mode, since the powder quick-setting agent has been mixed in the manufacturing stage to the amorphous refractory composition, there is no external addition method. The device is difficult to construct or operate. However, the present inventors have found that since the powder quick-setting admixture is already contained in the material, it is sometimes necessary to pay attention to the management, such as limiting the usable (construction) storage period or avoiding for the purpose of constructing a stable refractory. Storage under high temperature and humidity. That is to say, in the preservation over a long period of time or in the storage under high temperature and high humidity, the characteristics of the quick-setting agent change with time, and there is a decrease in the construction property such as dusting and rebound loss during construction. And the quality of the refractory produced is damaged.

Accordingly, an object of the present invention is to provide a spray coating method for a monolithic refractory, which can solve the internal addition method even in the air flow transport type spray construction method described above, even if it is constituted by a simple device equivalent to the internal addition method. The disadvantage is that the storage and storage management of the amorphous refractory material is complicated, and the original quality of the material can be highly maintained.

The air transport type spray coating method of the monolithic refractory of the present invention is characterized in that it has the following steps: a mixing step of transporting an unshaped refractory material containing a fire resistant aggregate, a refractory powder, a binder and a dispersant in air flow Instantly adding a powder quick-setting admixture and mixing to form an amorphous refractory composition; the air flow transporting step causes the amorphous refractory composition to be carried in a gas state in a powder state, and is fed into the transport pipe from one end side of the transport pipe And transporting the water to the other end; adding a construction water to the amorphous refractory composition in the transport of the airflow transporting step; and spraying the unshaped refractory composition having the added water from the spray nozzle Sprayed on the construction object.

According to the air transport type spray coating method of the monolithic refractory of the present invention, by adding the powder quick-setting agent before the air flow, the procedure of transporting the powder quick-setting agent to the vicinity of the nozzle is not required, and the method is not required. It is composed of a complicated device that is supplied to the conveying pipe under high pressure, and is not mixed with the powder quick-setting admixture until the use is instantaneous. Therefore, no complicated material storage management is required, and the refractory property can be produced. Stabilizer.

1‧‧‧ Spraying construction equipment

2‧‧‧Air transporter

3‧‧‧Transport tube

4‧‧‧ Construction water addition agency

5‧‧‧ Construction Water Addition Department

6‧‧‧ spray nozzle

7‧‧‧Quantitative conveyor

8‧‧‧ Accelerator supply machine

9‧‧‧Compressor

20‧‧‧Unshaped refractory

21‧‧‧Powder accelerator

22‧‧‧Unshaped refractory composition

23‧‧‧ Construction wall

24‧‧‧ Construction refractory

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a flow-through spray coating construction method for an amorphous refractory according to an embodiment of the present invention.

Form for implementing the invention

Hereinafter, the spray coating method of the monolithic refractory of the present invention will be described in detail with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a flow-through spray coating construction method for an amorphous refractory according to an embodiment of the present invention.

First, an air flow type spray coating apparatus for an amorphous refractory used herein will be described. As shown in Fig. 1, the spray coating apparatus 1 is composed of an air flow conveyor 2, a transport pipe 3, a construction water adding mechanism 4, a construction water adding unit 5, a spray nozzle 6, a quantitative conveyor 7, a quick-setting admixer 8, and compression. The machine 9 is constructed.

The air transporter 2 uses the compressed air of the compressor 9 to feed the amorphous refractory composition 22 into the transport pipe 3 at a predetermined solid/gas ratio, and transports the sent unshaped refractory composition 22 from the transport pipe 3. One of the end sides (the side of the air transporter 2) is transported toward the other end side (the side of the spray nozzle 6), so that the amorphous refractory composition 22 can be transported in a powder state.

Moreover, in the air conveyor 2, it is preferable to do not per unit time. The supply amount of the shaped refractory composition 22 and the amount of gas supplied to the air are set to be constant, and the amorphous refractory composition 22 which continues to have a predetermined amount (solid/gas ratio) is transported into the transport tube 3. The solid/gas ratio is usually from 1/200 to 1/400 in volume ratio.

The transport tube 3 is a passage for transporting the powdery amorphous refractory composition 22 in a powder state by a gas flow, and the amorphous refractory composition in a wet state can be transported to the spray nozzle 6 even when the construction water is added on the way. . In other words, the transport tube 3 may be any one that can connect the air transporter 2 and the spray nozzle 6 and stably transport the amorphous refractory composition 22 in a powdery and/or wet state.

As the transport tube 3, a metal pipe such as steel or a resin hose made of rubber or polyethylene is preferably used. In this case, the inner diameter of the transport tube 3 may be appropriately selected in accordance with the amount of the unshaped refractory composition 22 to be transported or the construction site, and is usually preferably 65 mm or less. Once the inner diameter of the transport tube exceeds 65 mm, the amount of spray per unit time will become too large, and once the inner diameter is too small, pressure loss will occur. Among them, the inner diameter of the transport tube 3 is preferably 25 to 65 mm.

At this time, the diameter of the transport tube 3 can be appropriately selected in accordance with the amount or size of the unshaped refractory composition 22 to be transported, etc., and the ratio of the largest particle diameter/the inner diameter of the transport tube in the amorphous refractory composition 22 used is 1/7~1/3 is better, usually use a transport tube with an inner diameter of 38~65mm.

The length of the transport tube 3 is not limited as long as the airflow can be stably carried out. For example, it can be transported over a long distance of a horizontal distance of about 200 m and a height of about 150 m. Further, the shape of the transport tube 3 is as described above, such as a resin. It is ideal for the formation of flexible materials that are easy to configure and move in accordance with the site conditions. Further, even if the construction site is high, the unshaped refractory composition 22 can be sprayed to a high place by the transport pipe 3 of the present invention, and the spray nozzle 6 can be moved to the vicinity of the construction object, so that stable construction can be performed.

The construction water adding means 4 is a type of refractory fire-resistant material in which the unshaped refractory composition 22 is wetted by adding the construction water to the transfer pipe 3 in the powdery amorphous refractory composition 22 to be in a wet state. The composition 22 is transported to the spray nozzle 6 by the force of the airflow of the air transporter 2. The construction water supplied to the transportation pipe 3 by the construction water adding means 4 is supplied to the transportation pipe by the construction water adding unit 5 to supply the construction water supplied by the construction water adding means 4.

Here, the construction water adding means 4 is preferably a metal pipe made of stainless steel or the like, and a resin hose made of rubber or polyethylene. At this time, the inner diameter of the construction water adding mechanism 4 may be appropriately selected in accordance with the amount of construction water supplied or the condition of the construction site, and is usually preferably 9 to 25 mm.

Further, the construction water adding means 4 is connected to the water addition port provided in the middle of the transport pipe 3 so that the construction water can be supplied to the inside of the transport pipe 3, and the construction water adding portion 5 is provided. The position of the construction water adding portion 5 is preferably a position from the tip end of the spray nozzle 6 of 0.3 to 15 m. If it is shorter than 0.3 m, the refractory composition 22 and the construction water cannot be sufficiently mixed, and it is impossible to construct a refractory having sufficient characteristics; once it is longer than 15 m, it is easy to deposit an amorphous refractory composition in the conveying pipe 3. 22. The amount of spray is lowered or the inside of the transport tube 3 is blocked and the spray itself cannot be performed.

The spray nozzle 6 is installed at the front end of the transport pipe 3, and the construction has been added. The unshaped refractory composition 22 of water is sprayed toward the object to be coated. As the spray nozzle 6, a spray nozzle of a conventional refractory composition which is conventionally used may be used.

The quantitative conveyor 7 can supply the unshaped refractory 20 to the airflow conveyor 2 quantitatively and continuously at an arbitrary setting value, and for example, Plimate II (trade name) manufactured by PLIBRICO Co., Ltd., Japan.

The quick-setting agent feeder 8 can supply the powder quick-setting agent 21 quantitatively and continuously to the monolithic refractory 20 conveyed by the quantitative conveyor 7 at an arbitrary set value, so that it is a supply of a small amount of powder. Do not ask the way. For example, a Micron Feeder (trade name, manufactured by Aishin Nano Technologies Co., Ltd.) or Milli-feeder (made by Alpha Corporation, trade name) can be mentioned.

Here, the monolithic refractory 20 conveyed by the quantitative conveyor 7 and the powder quick-setting agent 21 supplied by the quick-setting admixer 8 are mixed into the amorphous refractory composition 22, in order to allow the refractory to be applied. The characteristics are stably exhibited, and are mixed at the time of use (construction), and a mixing mechanism capable of uniformly mixing the amorphous refractory 20 and the powder quick-setting admixture 21 is preferably provided.

The mixing mechanism may use the quantitative conveyor 7 before being supplied to the air conveyor 2, or may provide an independent mixing mechanism to stir and mix the amorphous refractory 20 and the powder quick-setting agent 21 to form an amorphous refractory composition. Object 22. In this case, the mixing method of the amorphous refractory material 20 and the powder quick-setting admixture 21 is not particularly limited.

When the mixing conveyor 7 is provided with the mixing mechanism, the mechanism for adding the powder quick-setting agent 21 to the monolithic refractory 20 in the middle of the air transporter 2 and metering it to the air transporter 2 can be used, for example, by a screw conveyor type. The supply mechanism can also easily attach a stirring plate or the like for increasing the mixing ability to the screw. Here, the transport and supply mechanism of the quantitative conveyor 7 is not particularly limited as long as the amorphous refractory 20 and the powder quick-setting agent 21 are mixed and supplied to the air transporter 2 in a quantitative manner.

The compressor 9 supplies the compressed gas to the air conveyor 2. The compressed gas system supplied here introduces the amorphous refractory composition 22 supplied from the quantitative conveyor 7 into the transport pipe 3 in the air transporter 2, and the amorphous refractory composition 22 is placed in the transport pipe 3 in a powder state. Being shipped.

Next, the spray coating method of the present invention will be described. In the spray coating method, it is characterized in that an amorphous refractory composition 22 is produced by adding and mixing the powder quick-setting admixture 21 to the amorphous refractory 20 at a place of use before the air current is transported. Here, before the airflow conveyance is carried out before the airflow is carried out, it is intended to add and mix the unshaped refractory 20 to the airflow conveyor 2 at the construction site. Typically, the powdery quick-setting agent 21 is added and mixed at a predetermined ratio to the unshaped refractory material 20 being transported as described above by the metering conveyor 7, and the unshaped refractory material and the powder are separately prepared at the construction site. The quick-setting admixture can be mixed at the beginning of construction.

The monolithic refractory composition 22 obtained by the above method is transported in the transport tube 3 in a powder state by the compressed gas sent from the compressor 9 in the air transporter 2. The air transporter 2 is not particularly limited as long as it can transport the powder of the amorphous refractory composition 22 by a gas flow. For example, a sprayer such as Need Gun (trade name) manufactured by Japan's PLIBRICO Co., Ltd. can be used.

However, the above-mentioned powdery amorphous refractory composition 22 is fed into the transport. When the pipe 3 is fed, the predetermined amount of the amorphous refractory composition 22 can be continuously supplied to the air transporter 2, and as the airflow source, for example, the compressed air can be supplied by the compressor 9, thereby making the amorphous refractory composition of each time. The amount of transport of the substance 22 is stable and quantitative.

Then, the monolithic refractory composition 22 that has been fed into the transport tube 3 is transported in the transport tube 3 toward the spray nozzle 6 by the air flow using the compressed air supplied to the air transport unit 2. At this time, although the length of the transport tube 3 is also related to the capacity of the air transporter 2, in the present invention, since it can be transported in a powder form, it is characterized in that it can be constructed over an extremely long distance, and is conventionally wet. The transport distance of up to 100 m in the spray application method can be as long as 200 m in the present invention.

In this way, the construction water can be added to the monolithic refractory composition 22 transported in the transport pipe 3 in the middle of the transport pipe 3 by the construction water adding mechanism 4. The position of the construction water adding portion 5 for actually supplying the construction water is preferably 0.3 to 15 m upstream from the front end of the spray nozzle 6, and when the water is added at a position lower than 0.3 m, there may be an amorphous refractory composition 22 and The construction water cannot be sufficiently mixed to construct a refractory having sufficient characteristics. On the other hand, when water is added at a position exceeding 15 m, the pressure increase resistance is increased by the addition of water, and the transporting force under compressed air is insufficient to cause the transport tube to clog, which is not preferable. The water addition position is preferably 0.3 to 5 m upstream from the front end of the spray nozzle 6.

The amount of construction water added to the amorphous refractory composition 22 in the present invention is the substantial amount of construction water required for the spray application of the refractory. Here, substantially all of the required amounts are indicated, depending on the circumstances. Add a small amount of water at other locations. For example, in order to prevent the powder from flying, a small amount of water may be added to the amorphous refractory composition 22 to make it a so-called pre-wet state.

For example, in the study of the dispersion structure of powder, water and air, generally, the three types of structures can adopt various structures, and the wet state of the refractory composition in the transport tube of the present invention is that air is enclosed in the powder. The continuous particles of water and water constitute the so-called "fibril (II) domain" (Mei-Yu: Xuezheng 136 Committee, Unshaped Refractory Construction Technology Conference), so it is considered that the wet state of the present invention is unshaped and fire-resistant. The composition 22 is transported while floating in the transport tube. However, this is a presumption of the mechanism and is not intended to be an interpreter of the invention.

In addition, since the construction water added here is supplied to the construction water addition unit 5 by the construction water addition mechanism 4, and the supply source of the construction water is generally provided in the vicinity of the air flow conveyor 2, the construction water is added. The mechanism 4 is set to have the same length as the transport tube 3.

The powdery amorphous refractory composition 22 is added to the powdery amorphous refractory composition 22 in a wet state with a predetermined mixing ratio, and is transported to the spray nozzle 6 to be directly sprayed to the construction wall surface 23 of the construction object at a high pressure. On the other hand, the transport air is degassed into the outside air by the flushing when it is sprayed onto the construction wall surface 23. After degassing of the sprayed amorphous refractory, it will rapidly agglomerate under the effect of the quick-setting agent, and then harden it into a construction refractory 24 to construct a strong furnace wall. However, it is also possible to use a mold frame or the like in accordance with the requirements during construction.

Further, the unshaped refractory material 20 used in the present embodiment is the same as the conventionally used material, and is, for example, a powder containing a fire-resistant aggregate, a refractory powder, a binder, and a dispersant.

Here, as the refractory aggregate, it is preferably selected from alumina, bauxite, diaspore, mullite, kyanite, aluminum shale, clay clinker, vermiculite, pyrophyllite, and strontium. Carbon, borite, chromite, spinel, magnesia, zircon, zircon, chromia, tantalum nitride, aluminum nitride, tantalum carbide, boron carbide, black lead, etc., titanium boride and boron One or more of the group consisting of zirconium.

Further, the refractory powder contained in the amorphous refractory material 20 is embedded in the gap between the refractory aggregates to form a joint portion to which the refractory aggregate is bonded, and the average particle diameter may be 150 μm or less, and the average particle diameter should be used. In the case of 10 μm or less, it is preferred to use a fire-resistant ultrafine powder of 5 μm or less. As the fire-resistant ultrafine powder, alumina, fumed silica, or the like is preferred. The alumina and the smoked mash can be used not only in the form of a powder, but also in the form of an alumina melt, a cerium oxide melt or a colloidal vermiculite. The refractory powder is preferably 30 to 60 parts by mass, and particularly preferably 40 to 50 parts by mass, per 100 parts by mass of the refractory aggregate.

As the refractory powder, the above-mentioned fire-resistant ultrafine powder may be added, and other materials having a particle size larger than the fire-resistant ultrafine powder but having an average particle diameter of 30 μm or less may be added. As the material, there may be mentioned, for example, alumina, titania, bauxite, diaspore, mullite, aluminum shale, clay clinker, pyrophyllite, sillimanite, andalusite, vermiculite, chromite , amorphous crystals of spinel, magnesia, zirconium, zircon, chromia, tantalum nitride, aluminum nitride, tantalum carbide, boron carbide, titanium boride, zirconium boride, bentonite or cerium oxide Yttrium oxide. These may be used alone or in combination. However, as in the refractory material of the conventional dry construction method, in the present invention, it is preferred to reduce the viscosity of the refractory composition as much as possible to the clay material when the moisture is added. The content of the fire clay, the kaolin, the bentonite, and the like is preferably set to be 3 parts by mass or less based on 100 parts by mass of the fire resistant aggregate.

The binder contained in the amorphous refractory 20 functions as a binder of the amorphous refractory, and alumina cement is desirably used. When alumina cement is used as the binder, the construction body can maintain strength in a wide range from normal temperature to high temperature. As the binder, a phosphate such as phosphoric acid or aluminum phosphate, a citrate such as sodium citrate or potassium citrate, a lignosulfonate, or a water-soluble phenol can be used. The binder is preferably from 2.5 to 20 parts by mass, and particularly preferably from 5 to 12 parts by mass, per 100 parts by mass of the refractory aggregate.

In the present invention, the dispersing agent contained in the amorphous refractory composition is quite important, and in the case where the dispersing agent is not contained, when the construction water is added to the powdery composition, the viscosity is increased to cause the conveying pipe to clog. The dispersing agent is selected from the group consisting of condensed phosphates such as sodium tetrapolyphosphate and sodium hexametaphosphate, carboxylates such as polycarboxylates and polyacrylates, and sulfonates such as melamine sulfonate and β-naphthalenesulfonate. One or more of the constituent groups are preferable. The dispersant is preferably 0.03 to 1.5 parts by mass, and particularly preferably 0.08 to 0.35 parts by mass, per 100 parts by mass of the fire-resistant aggregate.

The powder quick-setting agent 21 used in the present invention is added and mixed to an amorphous refractory material under normal pressure before being transported in the air stream, and is not required to be fed into the transport tube under high pressure as in the air flow transport, so that it is easy The quantitative supply to the amorphous refractory 20 is not limited to a known device as long as it is prepared in a quantitative manner.

Here, as a quick-setting admixture, it is selected from the group consisting of citrates such as sodium citrate and potassium citrate; aluminates such as sodium aluminate, potassium aluminate, and calcium aluminate; and carbonic acid such as sodium carbonate, potassium carbonate, and sodium hydrogencarbonate. Salt; sulfates such as sodium sulfate, potassium sulfate, 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 , a calcium aluminate such as 11CaO‧7Al ₂ O ₃ ‧ CaF ₂ ; and a calcium salt such as calcium oxide, calcium hydroxide or calcium chloride or a mixture thereof is preferably one or more. Further, it is not limited to the above, and a substance known as a quick-setting admixture and a coagulant may be used. From the standpoint of being easy to start, low in cost, and excellent in characteristics, it is preferable to use sodium aluminate in the above-mentioned quick-setting admixture. Since sodium aluminate has a high melting point, the refractoriness of the refractory is not lowered, and the properties of the refractory are not impaired.

These quick-setting admixtures are in the form of powder and have an average particle diameter of preferably 20 to 200 μm, preferably 50 to 100 μm.

The amount of the accelerator to be added is preferably 0.05 to 3 parts by mass based on 100 parts by mass of the amorphous refractory material excluding the additives such as the dispersant or the retarder. Once it is less than 0.05 parts by mass, even if it is a quick-setting admixture with good performance, there is still insufficient speed of coagulation to cause the refractory flow of the sprayed construction to fall, and on the other hand, if a large amount of injection exceeds 3 parts by mass, it may be hard to harden and hard to harden. The performance as a refractory is reduced by spraying or heat resistance or corrosion resistance. The amount of the accelerator to be added may also vary depending on the type of the accelerator. Therefore, it is preferred to adjust the amount of the injection by the type of the accelerator.

Further, in the present spray application method, by adding a retarder which is ideally added in an amount of 0.002 to 0.2 parts by mass with respect to 100 parts by mass of the unshaped refractory material, the coagulation time can be controlled, and the fireproof construction can be stably performed. Things. As the retarder, a weak acid such as oxalic acid, boric acid, malic acid, citric acid, or lignosulfonate can be suitably used.

In the spray application method of the present embodiment, since the addition of the quick-setting agent to the unshaped refractory is performed at the site of the spray application immediately before the construction, it is difficult to change the characteristics of the unshaped refractory material, and the material is strict. Stable refractories can be applied after long-term storage under severe conditions.

Moreover, similarly to the conventional airflow type spray coating construction method, the following advantages are obtained.

(1) Since the flow of the gas stream using the powdery amorphous refractory composition is carried out, it is not necessary to carry out the mixed chain operation of the unshaped refractory composition by the large-scale mixer, and it is not necessary to use a pressure-feeding mixture having a large pressure loss. Chain pump.

(2) Since the amorphous refractory composition is transported in a bad soil state in the conventional wet spray application method, the transport distance limit from the supply point to the spray place is about 100 mm in the horizontal distance and about 60 m in the height, but in the In the present invention, since the mixing of the amorphous refractory composition and the construction water is carried out in the conveying pipe, there is no need to worry about clogging in the conveying pipe, and it is possible to carry out long-distance transportation of about 200 m and construction at a height of about 150 m.

(3) The amorphous refractory composition also contains a quick-setting agent, so that it is not necessary to add or control the device of the accelerator in the middle of the transport pipe.

(4) Since there is no unshaped refractory composition attached to the transport pipe and does not remain in the transport pipe after construction, the cleaning and maintenance work can be greatly reduced, and the irregular shape due to the residual in the transport pipe can be significantly reduced. Loss of refractory material.

(5) The spray refractory produced has excellent characteristics of uniformity and high strength.

Example

The invention will now be described in further detail by way of examples, but the invention It is not construed by any limitation of this embodiment.

(Example 1)

The spray-coating apparatus 1 of the monolithic refractory shown in Fig. 1 was used, and a powdery amorphous refractory composition composed of the composition shown in Table 1 was used as the amorphous refractory composition, and air-flow type spraying was carried out in the following manner. construction. Further, the content is a value other than the dispersant and the retarder, and the mass fraction of the amorphous refractory composition per 100 parts by mass.

First, an amorphous refractory material mixed with a refractory aggregate, a refractory powder, an alumina cement as a binder, a dispersant, and a retarder is used by a quantitative conveyor 7 (Plimate II, manufactured by Japan's PLIBRICO Co., Ltd.) )) is transported to the air transporter 2 (Need Gun 400 (trade name) manufactured by Japan's PLIBRICO Co., Ltd.), and a predetermined amount of accelerator is added by the quick-setting admixer 8 during the transport to make it the ratio of the above Table 1. . Here, the material used as the amorphous refractory composition is used immediately after preparation (usually) and stored at 30 ° C for 120 days (after storage), and refractory construction is carried out by the same operation as described below. .

The above-mentioned Plimate II (trade name) quantitatively supplies an unshaped refractory composition to which a quick-setting admixture is added to the air transporter 2, and the mechanism is to quantitatively cut out and supply the material by a supply mechanism called a screw conveyor. At the time of the supply, the amorphous refractory material and the quick-setting admixture can be uniformly mixed.

Next, the air transporter 2 continuously doses the amorphous refractory composition having a bulk density of 2.0 g/cm ³ from the quantitative conveyor 7 at an amount of 1 m ³ /hr, while the air compressor is at 5 Nm ³ /min. The compressed air is delivered at a flow rate to feed the amorphous refractory composition into the transfer tube 3. Further, as the transport tube 3, a rubber hose having a length of 40 m and an inner diameter of 38 mm from the air transport conveyor 2 to the spray nozzle 6 was used.

In the transport pipe 3, tap water (construction water) is added from the tip end of the spray nozzle 6 at a position of 0.8 m while conveying the air stream of the amorphous refractory composition.

The amorphous refractory composition in the wet state of the added construction water is transported to the spray nozzle 6 and directly sprayed to a longitudinal direction of 400 mm × a width of 400 mm × thickness 100mm spray panel. At this time, the discharge amount of the amorphous refractory composition was 2000 kg/hr and the spray pressure was 0.3 MPa.

(Comparative Example 1)

In Comparative Example 1, as the amorphous refractory composition to be used, a spray coating of an amorphous refractory composition was carried out in the same manner as in Example 1 except that all the materials were previously mixed. In other words, the following two types of construction were carried out: spray coating was carried out immediately after mixing all the materials to prepare the amorphous refractory composition, and the unshaped refractory composition was stored at 30 ° C for 120 days, and then spray-coated.

(test example)

In the first embodiment and the comparative example 1, the construction of the material immediately after the preparation of the material and the construction of the material after high-temperature storage were carried out, and each of the five spray panels was separately dried for one day or more. The cutting blade was cut in the thickness direction to observe the cut surface of the working body, and the bulk density and bending strength of the panel after drying at 110 ° C were further measured, and the test results of the test were collectively shown in Table 2.

*1 Body density: Measured in accordance with JIS R 2655.

*2 Bending strength: Measured in accordance with JIS R 2553.

*3 Cut surface observation: The cut surface cut in the thickness direction was visually observed, and the local and layered peeling portions (layered impurities) of the aggregate were investigated. The evaluation is carried out as follows.

[The bureau of the aggregate] has: confirm that there is a bureau; no: confirm that there is no bureau

[Layered impurities]: those with peeling parts; none: those without peeling parts

*4 Fillability: The number of cut surfaces cut in the thickness direction was visually observed to determine the presence or absence of minute voids.

Good: no gap on either side; slightly worse: there are gaps in the face below half of the cut surface; difference: more than half of the faces have gaps

From the results, it is understood that, by the construction method of the present invention, even after storage of the unshaped refractory material at a high temperature, the properties of the refractory obtained are neither lowered nor preferable.

Industrial availability

The spray coating method of the monolithic refractory of the present invention can be utilized for the construction of an amorphous refractory which is sprayed by air flow.

The entire disclosure of Japanese Patent Application No. 2012-080934, filed on-

1‧‧‧ Spraying construction equipment

2‧‧‧Air transporter

3‧‧‧Transport tube

4‧‧‧ Construction water addition agency

5‧‧‧ Construction Water Addition Department

6‧‧‧ spray nozzle

7‧‧‧Quantitative conveyor

8‧‧‧ Accelerator supply machine

9‧‧‧Compressor

20‧‧‧Unshaped refractory

21‧‧‧Powder accelerator

22‧‧‧Unshaped refractory composition

23‧‧‧ Construction wall

24‧‧‧ Construction refractory

Claims (8)

An air-flow type spray coating construction method for an amorphous refractory, characterized by the following steps: a mixing step of an unshaped refractory material containing a fire-resistant aggregate, a refractory powder, a binder and a dispersant The powder refractory agent is added and mixed to form an amorphous refractory composition; the air flow transport step is such that the amorphous refractory composition is carried in a gas state in a state of powder, and is fed into the transport tube from one end side of the transport tube. And transporting the water to the other end; adding a construction water to the amorphous refractory composition in the transport of the airflow transporting step; and spraying the unshaped refractory composition having the added water from the spray nozzle Sprayed on the construction object. The air-flow type spray coating method of an amorphous refractory according to claim 1, wherein the mixing step is performed by supplying a predetermined amount of the aforementioned powder quick-setting agent to the amorphous refractory material to be quantitatively transported and mixing. . The air-flow type spray coating method of the amorphous refractory according to claim 1 or 2, wherein the fire-resistant powder is a fire-resistant ultrafine powder having an average particle diameter of 10 μm or less, the binder is alumina cement, and the dispersion is The agent is a condensed phosphate, a carboxylate or a sulfonate, and the powder accelerator is an alkali metal or alkaline earth metal citrate, aluminate, carbonate or sulfate. The air-jet spray coating construction method of the amorphous refractory of claim 3, wherein the fire-resistant ultrafine powder is alumina and/or smoked mash. An airborne spray coating construction method for an amorphous refractory according to claim 3 or 4, wherein the powder quick-setting agent is sodium aluminate. The air-flow type spray coating method for an amorphous refractory according to any one of claims 1 to 5, wherein the content of the refractory powder, the binder, the dispersant and the powder quick-setting agent is the aforementioned fire-resistant bone The material is 30 to 60 parts by mass, 2.5 to 20 parts by mass, 0.03 to 1.5 parts by mass, and 0.07 to 4.5 parts by mass, respectively, per 100 parts by mass. The air-flow type spray coating method for an amorphous refractory according to any one of claims 1 to 6, wherein the application water is added at an upstream position of 0.3 to 15 m from the tip end of the nozzle. A refractory constructed by an air-jet spray coating construction method of an amorphous refractory according to any one of claims 1 to 7.