WO2013147080A1

WO2013147080A1 - Air-current transport spray application method for unshaped refractories

Info

Publication number: WO2013147080A1
Application number: PCT/JP2013/059373
Authority: WO
Inventors: 高橋　明彦; 正史大住
Original assignee: Ａｇｃプライブリコ株式会社
Priority date: 2012-03-30
Filing date: 2013-03-28
Publication date: 2013-10-03
Also published as: TW201402250A; JPWO2013147080A1

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 conveying type spray construction method for irregular refractories

The present invention relates to an airflow conveying type spraying method for an amorphous refractory, and in particular, suppresses a change in properties of the amorphous refractory material, and sprays the amorphous refractory stably with simple operation. The present invention relates to an air current conveying type spraying construction method capable of performing construction.

Conventionally, the spraying construction method is known as an effective construction method for irregular refractories. Compared with the casting method, this construction method does not require a casting mold, and can be easily applied to places where the shape is complicated and the framework is difficult, so it is widely used in more and more fields in recent years. ing. Such spraying methods can be broadly classified into a wet pumping method using a pumping method and a dry spraying method using a pneumatic method.

The wet spraying construction method is a construction method in which spraying is performed after preparing a kneaded material called “kneaded clay” in which a refractory composition for spraying and construction water are sufficiently kneaded in advance. The kneaded material is kneaded until a fluid flow value (using JIS cone) that can be pumped using a mixer reaches about 200 mm, and this is fed to the pump and transported through the transport pipe. Then, by adding a quick setting agent for agglomerating the clay at the nozzle and supplying compressed air, it sprays on the construction object and agglomerates relatively instantaneously to construct a refractory such as a furnace wall. To do.

In such a wet spraying method, a refractory having a uniform quality and excellent physical properties can be obtained, but when supplying the spraying material to the pressure feed pump as described above, sufficient fluidity is obtained using a mixer. Since it is necessary to knead the spray material, a large mixer and a large number of personnel are required. Moreover, since it pumps with a pump, management of the amount of kneading | mixing water for obtaining appropriate fluidity | liquidity is difficult, for example, when fluidity | liquidity is small, it will block | occlude in a pump or a conveyance pipe. If too much kneading water is added to increase the fluidity, the fine refractory aggregate and the fine refractory powder contained in the refractory material for spraying are separated, making it impossible to convey the material. As described above, the wet spray construction method has many unstable elements during construction on site.

Furthermore, in order to transport the kneaded clay for a long distance by pumping, a large pump is required due to the high viscosity of the clay, and the transport distance is shorter than that of the dry spraying method. The distance is about 100m at most. Furthermore, in the wet spraying method using a pump, when the construction is completed, the kneaded clay remains in the transfer pipe, so there is a problem that a lot of material is lost and that it takes a lot of people and time to take out and clean it. .

On the other hand, the dry spraying method is for powdery spraying that contains a hardener such as alumina cement that hardens when combined with water, and refractory powder such as clay to improve adhesion during spraying. Refractory material is supplied to a pneumatic feeding sprayer and pneumatically fed through the transfer pipe. Construction water is added to the powdered refractory material for spraying by the spray nozzle, and the construction water is added to the powdered refractory composition for spraying to create a highly viscous adhesive state. Is blown out through the nozzle, adheres and hardens to the construction object, and builds a refractory.

In such a dry spraying construction method, the spraying refractory composition is pneumatically fed in powder form, so that the transportation pipe is not clogged, so that transportation is easy and long distance transportation is possible. Therefore, this method has the advantage that it can be installed at a distant place or a high place with a spraying machine or a fireproofing composition for spraying installed on the ground, and it can be applied to various work sites. Applicable.

On the other hand, the dry spray construction method mixes the powdered amorphous refractory composition and construction water in the nozzle to create a viscous adhesion state, so the contact time of the refractory composition and construction water is short. . In addition, if the amount of refractory composition fed pneumatically is not constant, the amount of construction water to be added must also be changed accordingly, the operator's adjustment of the amount of water will not catch up, and the amount of construction water will also vary In some cases, the construction water does not reach the specified amount or the mixing is not sufficiently uniform, so the quality of the constructed refractory furnace wall becomes non-uniform, resulting in a stable and high-quality refractory with high strength. It tends to be difficult to obtain.

On the other hand, the material and quick setting agent used in the wet spraying method are used, but the material is pneumatically conveyed to the vicinity of the nozzle in the form of powder without forming a clay with a mixer in advance. After adding construction water on the upstream side, it is transported as it is and sprayed onto the construction object, and it is agglomerated in a relatively short time to build a refractory material (hereinafter referred to as dry spraying construction method). In order to distinguish from this, this construction method is referred to as an air current conveying type spraying construction method).

In this air current conveying type spraying method, the powder material and construction water are mixed in the conveying pipe after the addition of water, so that a large mixer, a pressure pump and a large number of personnel are not required. Moreover, since it is conveyed with powder in the conveying pipe, it is possible to construct at a long distance and at a high place.

At present, due to the difference in the addition method of the quick setting agent, the air current transfer spraying method is an external addition method in which the construction water is added upstream of the nozzle, and then the air transfer is continued and the quick setting agent is added near the nozzle. Known (for example, see Patent Documents 1 and 2) and an internal addition method (for example, refer to Patent Document 3) in which a powder quick-setting agent is added and mixed in advance during the production of an irregular refractory composition. It has been.

Japanese Unexamined Patent Publication No. 10-316478 Japanese Unexamined Patent Publication No. 2000-356475 Japanese Unexamined Patent Publication No. 2002-213880

In the above-mentioned air current conveyance type spraying method, the external addition method conveys the powder accelerating agent to the vicinity of the nozzle and adds the powder accelerating agent at a pressure higher than the pressure in the conveying pipe being pneumatically fed. It is necessary to add pressure. For this reason, a quick setting agent supply device, a quick setting agent transport pipe, a quick setting agent addition unit, etc. are required, and the device configuration is complicated. In particular, a special device that can supply the quick setting agent at high pressure is essential. It was. In addition, since the addition position of the powder quick-setting agent is in the vicinity of the nozzle as described above, the installer who operates the nozzle on the construction object transports the quick-setting agent in addition to the construction water transport pipe and the addition section. A tube and an addition part were added, and the work burden was remarkably increased.

On the other hand, in the internal addition method, since the powder accelerating agent is already mixed in the irregular refractory composition at the manufacturing stage, there is no problem in apparatus configuration and operation as in the external addition method. However, because the powder quick-setting agent is included in the material, in order to construct a stable refractory material, such as limiting the storage period until use (construction) and avoiding storage at high temperature and high humidity, It has been newly found by the present inventors that care may be required. In other words, in storage over a long period of time or in a high temperature and high humidity environment, it is possible to obtain a decrease in workability such as dust generation during construction and an increase in rebound loss due to changes in the characteristics of the quick setting agent. It has been found that the quality of the refractory may be impaired.

Therefore, the present invention is a troublesome storage and storage management of the irregular refractory material, which is a weak point of the internal addition method, in the above-described air current conveying type spraying construction method, while having a simple device configuration equivalent to the internal addition method. The purpose is to provide a method for spraying irregular refractories that can eliminate the problem and maintain the original quality of the material.

In the present invention, the non-standard refractory air-conveying spraying method is applied to an amorphous refractory material containing a refractory aggregate, a refractory powder, a binder, and a dispersant, immediately before the air-flow conveyance. Addition and mixing to form an amorphous refractory composition, and the amorphous refractory composition is put in an air stream in a powder state and fed from one end side of the transport pipe into the transport pipe and transported to the other end side. An airflow conveying step, a construction water addition step of adding construction water to the amorphous refractory composition being conveyed in the airflow conveying step, and an amorphous refractory composition to which the construction water is added are applied from a spray nozzle. And a spraying step of spraying on the object.

According to the airflow conveyance type spray construction method of the amorphous refractory according to the present invention, the powder rapid setting agent is added just before the airflow conveyance so that the trouble of conveying the powder rapid curing agent to the vicinity of the nozzle is also conveyed. No complicated equipment configuration for supplying high pressure into the pipe is required, and since it is not mixed with the powder quick-setting agent until just before use, troublesome material storage management becomes unnecessary, and the obtained refractory characteristics can be stabilized. .

It is a figure explaining the air current conveyance type spray construction method of the irregular refractory which is one embodiment of the present invention.

Hereinafter, the method for spraying an irregular refractory according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram for explaining an airflow conveying type spray construction method for an irregular refractory according to an embodiment of the present invention.

First, the airflow conveying type spray construction device for the irregular refractory used here will be described. As shown in FIG. 1, this spray construction device 1 includes an air current transport device 2, a transport pipe 3, a construction water addition means 4, a construction water addition unit 5, a spray nozzle 6, and a quantitative transport device. 7, a quick setting agent supply machine 8, and a compressor 9.

The air current conveying machine 2 conveys the amorphous refractory composition 22 at a predetermined solid / gas ratio using the compressed air of the compressor 9 so that the amorphous refractory composition 22 can be conveyed in a powder state. The unshaped refractory composition 22 fed into the interior 3 is transported from one end side (airflow transporter 2 side) of the transport pipe 3 to the other end side (spraying nozzle 6 side).

Here, in the air current conveying machine 2, the supply amount of the amorphous refractory composition 22 per unit time and the amount of gas to be blown are made constant, and the predetermined amount (solid / gas ratio) of the amorphous refractory composition is always provided. It is preferable that the article 22 is transported in the transport pipe 3. This solid / gas ratio is a volume ratio, usually 1/200 to 1/400.

The conveyance pipe 3 is a passage that conveys the powdered amorphous refractory composition 22 in a powder state by an air flow, and the nozzle 6 sprays the wet amorphous refractory composition even when construction water is added on the way. Can be transported up to. That is, the transport pipe 3 is not limited as long as it can stably transport the powdery and / or wet amorphous refractory composition 22 by connecting the airflow transporter 2 and the spray nozzle 6.

The transport pipe 3 is preferably a conventionally used metal pipe such as steel or a resin hose made of rubber or polyethylene. At this time, the inner diameter of the conveying pipe 3 may be appropriately selected depending on the amount of the amorphous refractory composition 22 to be conveyed, the construction site, and the like, and is usually preferably 65 mm or less. If the inner diameter of the conveying pipe exceeds 65 mm, the spraying amount per unit time becomes too large, and if the inner diameter is excessively small, pressure loss occurs. In particular, the inner diameter of the transfer tube 3 is more preferably 25 to 65 mm.

At this time, the diameter of the transport pipe 3 can be appropriately selected depending on the amount and size of the amorphous refractory composition 22 to be transported, and the ratio of the maximum particle diameter in the amorphous refractory composition 22 to be used / the inner diameter of the transport pipe is It is preferable to set to 1/7 to 1/3. Usually, a conveying tube having an inner diameter of 38 to 65 mm may be used.

The length of the transfer pipe 3 is not limited as long as air flow can be stably carried out. For example, the transfer pipe 3 can be transferred at a horizontal distance of about 200 m and a height of about 150 m. Further, it is preferable that the shape of the transport pipe 3 is made of a flexible material such as resin as described above, because it can be easily arranged and moved in accordance with the situation at the site. Furthermore, even when the construction site is high, the conveying pipe 3 of the present invention blows the amorphous refractory composition 22 to the high location, and the spray nozzle 6 can be brought close to the construction object, so that it is stable. Enables construction.

The construction water addition means 4 adds construction water into the transport pipe 3 in which the powdery amorphous refractory composition 22 is transported to make the amorphous refractory composition 22 wet. The amorphous refractory composition 22 in a wet state is transported to the spray nozzle 6 by the force of the airflow generated by the airflow transporter 2. The construction water into the conveyance pipe 3 by the construction water addition means 4 is supplied by supplying the construction water sent by the construction water addition means 4 into the conveyance pipe by the construction water addition section 5.

Here, the construction water addition means 4 is preferably, for example, a metal pipe made of stainless steel or the like, or a resin hose made of rubber or polyethylene. At this time, the inner diameter of the construction water addition means 4 may be appropriately selected depending on the amount of construction water to be supplied, the situation at the construction site, and the like, and is usually preferably 9 to 25 mm.

The construction water addition means 4 is connected to a water addition port provided in the middle of the conveyance pipe 3 so that the construction water can be supplied into the conveyance pipe 3, and a construction water addition section 5 is provided. The position of the construction water addition part 5 is preferably 0.3 to 15 m from the tip of the spray nozzle 6. If the length is shorter than 0.3 m, the amorphous refractory composition 22 and the construction water may not be sufficiently mixed, and a refractory having sufficient characteristics cannot be constructed. If the length is longer than 15 m, the amorphous refractory composition is formed in the transport pipe 3. There is a possibility that the objects 22 are likely to accumulate, and the amount of spraying is reduced, or the inside of the transport pipe 3 is closed and spraying itself cannot be performed.

The spray nozzle 6 is attached to the tip of the transport pipe 3 and sprays the unshaped refractory composition 22 to which construction water is added to the construction object. As the spray nozzle 6, a spray nozzle of an amorphous fireproof composition that has been conventionally used may be used.

Quantitative conveyance machine 7 is capable of quantitatively and continuously supplying amorphous refractory material 20 to airflow conveyance machine 2 at an arbitrary set value. For example, Primate II (trade name) manufactured by Nihon Pribrico is available.

The quick setting agent supply unit 8 is capable of supplying the powder quick setting agent 21 in a predetermined amount and continuously to the amorphous refractory material 20 transported by the fixed amount transporting device 7, and supplying a small amount of powder. Any method can be used as long as it is a machine. For example, a micron feeder (manufactured by Aisin Nano Technologies, trade name), a millifeeder (manufactured by Alpha, trade name) and the like can be mentioned.

Here, the amorphous refractory material 20 conveyed by the quantitative conveying machine 7 and the powder quick-setting agent 21 supplied by the quick-setting agent supply machine 8 are mixed to become the amorphous refractory composition 22, but are applied. In order to stably exhibit the characteristics of the refractory, it is preferable to provide a mixing means that can be mixed at the time of use (construction) and can uniformly mix the amorphous refractory material 20 and the powder quick-setting agent 21.

As long as this mixing means is before supplying to the air current conveying machine 2, the fixed quantity conveying machine 7 may be used, or an independent mixing means is provided so that the amorphous refractory material 20 and the powder quick-setting agent 21 are provided. The amorphous refractory composition 22 may be obtained by stirring and mixing. At this time, the mixing method is not particularly limited as long as the amorphous refractory material 20 and the powder quick-setting agent 21 can be mixed together.

When mixing means is provided in the fixed amount transporter 7, when the powder quick-setting agent 21 is added to the amorphous refractory material 20 in the middle of transporting to the airflow transporter 2 and this is supplied to the airflow transporter 2 in a fixed amount. This mechanism, for example, a screw conveyance type supply mechanism, can be used, and a stirring plate can be easily added to the screw to increase the mixing ability. Here, the conveyance supply mechanism of the quantitative conveyance device 7 is not particularly limited as long as it can mix and supply the amorphous refractory material 20 and the powder quick-setting agent 21 to the airflow conveyance device 2.

The compressor 9 is for supplying compressed gas to the air current conveying machine 2. The compressed gas supplied here introduces the amorphous refractory composition 22 supplied from the quantitative conveyance device 7 into the conveyance pipe 3 in the air current conveyance device 2, and the amorphous refractory composition 22 remains in a powder state. It is transported in the transport pipe 3.

Next, the spraying construction method of the present invention will be described. This spray construction method is characterized in that an amorphous refractory composition 22 is obtained by adding and mixing a powder quick-setting agent 21 to the amorphous refractory material 20 at the place of use immediately before airflow conveyance. Here, “immediately before the air current conveyance” refers to the period before the air current conveyance and until the amorphous refractory material 20 is supplied to the air current conveyance device 2, and means addition and mixing at the construction site. Typically, the powder rapid setting agent 21 is added and mixed at a predetermined ratio to the amorphous refractory material 20 being conveyed by the above-described quantitative conveying machine 7. What is necessary is just to prepare a refractory material and a powder quick-setting agent separately, and to mix when starting construction.

The amorphous refractory composition 22 obtained in this way is transported in the transport pipe 3 in a powder state by the compressed gas sent from the compressor 9 in the airflow transporter 2. The airflow transport device 2 is not particularly limited as long as the powder of the amorphous refractory composition 22 can be transported by airflow. For example, a spraying device such as a need gun (trade name) manufactured by Nihon Pribrico is used. it can.

In addition, when feeding said powdery amorphous refractory composition 22 into the conveyance pipe 3, the predetermined amount of the amorphous refractory composition 22 is continuously supplied to the airflow conveyance machine 2, and the compressor 9 is used as the airflow source. For example, by supplying compressed air, the conveyance amount of the amorphous refractory composition 22 per hour can be stably quantified.

Then, the amorphous refractory composition 22 fed into the transport pipe 3 is transported in the direction of the spray nozzle 6 through the transport pipe 3 by the air current generated by the compressed air supplied to the air current transport machine 2. At this time, the length of the transport pipe 3 is also related to the capability of the airflow transport machine 2, but in the present invention, since it can be transported in powder form, it is characterized in that it can be applied over an extremely long distance. In the present invention, a conveying distance that is about 100 m at most in the wet spraying method can be as long as 200 m.

The construction water is added by the construction water addition means 4 in the middle of the transport pipe 3 to the amorphous refractory composition 22 transported in the transport pipe 3 in this way. The position of the construction water addition section 5 to which construction water is actually supplied is preferably 0.3 to 15 m upstream from the tip of the spray nozzle 6, and when the addition of water is performed at a position less than 0.3 m, The amorphous refractory composition 22 and the construction water are not sufficiently mixed, and a refractory having sufficient characteristics may not be constructed. On the other hand, when water is added at a position far beyond 15 m, it is not preferable because the pressure resistance increases due to the addition of water and the transport pipe tends to be blocked due to insufficient transport force with compressed air. The water addition position is more preferably 0.3 to 5 m upstream from the tip of the spray nozzle 6.

The amount of construction water added to the irregular refractory composition 22 in the present invention is substantially the entire amount of construction water necessary for spraying refractories. Here, “substantially” means almost all the required amount, and a small amount of water can optionally be added at other locations. For example, a small amount of water may be added to the amorphous refractory composition 22 in order to prevent the powder from rising, so that a so-called premoist state may be obtained.

For example, in a study on the structure of a powder, water and air dispersion system, in general, the three systems can take various structures, but the wet state of the refractory composition in the transport tube of the present invention The so-called “Filament (II) region” (Umeya: Gakken 136 Committee, Academic Refractory Construction Technology Council Study Group data), in which air is confined in continuous particles of water and water, Therefore, it is considered that the amorphous refractory composition 22 in the wet state of the present invention is transported while floating in the transport pipe. However, this is a mechanism estimation and does not constrain the interpretation of the present invention.

In addition, the construction water added here is supplied by the construction water addition means 4 up to the construction water addition unit 5, and the supply source of the construction water is usually arranged in the vicinity of the airflow transporter 2. Therefore, the construction water addition means 4 has the same length as the transport pipe 3.

In this way, the construction water corresponding to a predetermined mixing ratio is added to the powdered amorphous refractory composition 22 to make it wet, and it is transported to the spray nozzle 6 and directly applied to the construction wall 23 that is the construction object. Be sprayed. Note that the transfer air is degassed into the outside air by an impact when blown against the construction wall surface 23. The sprayed amorphous refractory is degassed and then rapidly agglomerates due to the effect of the quick-setting agent, and then hardens to become the construction refractory 24, and a strong furnace wall is constructed. In addition, you may use a formwork etc. as needed in the case of construction.

The amorphous refractory material 20 used in the present embodiment is the same as a conventionally used material, for example, a powdery material including a refractory aggregate, a refractory powder, a binder and a dispersant. is there.

Here, refractory aggregates include alumina, bauxite, diaspore, mullite, kayanite, van earth shale, chamotte, quartzite, pyrophyllite, sillimanite, andalusite, chromite, spinel, magnesia, zirconia, zircon. One or more selected from the group consisting of carbon such as chromia, silicon nitride, aluminum nitride, silicon carbide, boron carbide and graphite, titanium boride and zirconium boride are preferred.

In addition, the refractory powder contained in the amorphous refractory material 20 forms a joint for joining the refractory aggregate by filling the gaps of the refractory aggregate, and has an average particle diameter of 150 μm or less. The average particle diameter is preferably 10 μm or less, and a refractory ultrafine powder of 5 μm or less is more preferably used. As the refractory ultrafine powder, alumina, fumed silica and the like are preferable. Such alumina and fumed silica may be used in the form of not only powder but also a part of alumina sol, silica sol or colloidal silica. The refractory powder is preferably contained in an amount of 30 to 60 parts by weight, particularly 40 to 50 parts by weight, based on 100 parts by weight of the refractory aggregate.

As the refractory powder, in addition to the above refractory ultrafine powder, other materials having an average particle diameter of 30 μm or less can be added although the particle size is larger than that of the refractory ultrafine powder. Such materials include alumina, titania, bauxite, diaspore, mullite, van earth shale, chamotte, pyrophyllite, sillimanite, andalusite, quartzite, chromite, spinel, magnesia, zirconia, zircon, chromia, silicon nitride, Amorphous silica such as aluminum nitride, silicon carbide, boron carbide, titanium boride, zirconium boride, bentonite or silica may be mentioned. These are used alone or in combination. However, in the present invention, the amorphous refractory composition is a refractory material which is a clay-like material whose viscosity rapidly increases when moisture is added, as contained in the conventional refractory material of the dry construction method. Clay, kaolin, bentonite and the like are preferably reduced as much as possible, and preferably 3 parts by mass or less with respect to 100 parts by mass of the refractory aggregate.

The binder contained in the amorphous refractory material 20 functions as a binder for the amorphous refractory, and preferably, alumina cement is used. When alumina cement is used as a binder, the construction body can maintain strength in a wide range from room temperature to high temperature. As the binder, phosphates such as phosphoric acid and aluminum phosphate, silicates such as sodium silicate and potassium silicate, lignin sulfonate, water-soluble phenol and the like can be used. The binder is preferably contained in an amount of 2.5 to 20 parts by mass, particularly 5 to 12 parts by mass, with respect to 100 parts by mass of the refractory aggregate.

In the present invention, the dispersant contained in the amorphous refractory composition is important. When the dispersant is not contained, the viscosity increases when construction water is added to the powdered composition, and the conveying pipe is blocked. There is a risk of it. This dispersant is a condensed phosphate such as sodium tetrapolyphosphate and sodium hexametaphosphate, a carboxylate such as polycarboxylate and polyacrylate, a melamine sulfonate, and a sulfone such as β-naphthalene sulfonate. One or more selected from the group consisting of acid salts are preferred. The dispersant is preferably added in an amount of 0.03 to 1.5 parts by mass, particularly 0.08 to 0.35 parts by mass, with respect to 100 parts by mass of the refractory aggregate.

As described above, the powder accelerating agent 21 used in the present invention needs to be added to and mixed with an amorphous refractory material under normal pressure before airflow conveyance, and sent into the conveyance pipe at high pressure as in addition during airflow conveyance. Therefore, it is easy to quantitatively supply the amorphous refractory material 20, and a known device capable of quantitative supply may be prepared, and no special device is required.

Here, the quick setting agent includes silicates such as sodium silicate and potassium silicate, aluminates such as sodium aluminate, potassium aluminate and calcium aluminate, carbonates such as sodium carbonate, potassium carbonate and sodium bicarbonate. salt, 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 3 · One or more selected from calcium aluminates such as CaF ₂ , 11CaO · 7Al ₂ O ₃ · CaF ₂ , calcium salts such as calcium oxide, calcium hydroxide, calcium chloride or mixtures thereof are preferable. Moreover, it is not limited to the above, The substance called a known quick setting agent and a flocculant can also be used. Among the quick setting agents, it is preferable to use sodium aluminate because it is easily available, is inexpensive, and has excellent characteristics. Since sodium aluminate has a high melting point, it does not lower the fire resistance of the refractory and does not impair the properties of the refractory.

These quick setting agents are in the form of powder and the average particle diameter is preferably 20 to 200 μm, particularly 50 to 100 μm.

The addition amount of the quick setting agent should be 0.05 to 3 parts by mass on the basis of the outer weight and dry basis with respect to 100 parts by mass of the amorphous refractory material excluding additives such as dispersants and retarders. preferable. If the amount is less than 0.05 parts by mass, even if it is a good setting agent, the rapid setting speed may be insufficient and the refractory applied by spraying may flow down. On the other hand, if more than 3 parts by mass are injected, It hardens rapidly, making spraying difficult, and the performance as a refractory such as heat resistance and corrosion resistance decreases. Since the addition amount of the quick setting agent varies depending on the type of the quick setting agent, it is preferable to adjust the injection amount according to the type of the quick setting agent.

In addition, in this spray construction method, if necessary, by adding 0.002 to 0.2 parts by weight of a retarder as an outer shell to 100 parts by weight of the irregular refractory material, Aggregation time can be controlled and refractory can be sprayed stably. As the retarder, weak acids such as oxalic acid, boric acid, malic acid, citric acid and lignin sulfonate can be preferably used.

In the spray construction method of the present embodiment, the quick setting agent is added to the irregular refractory material immediately before the construction at the site of the spray construction. Stable refractories can be constructed even after long-term storage under various conditions.

Moreover, it has the following advantages like the conventional air current conveyance type spraying method.
(1) A pump that eliminates the need for kneading the sprayed amorphous refractory composition with a large mixer because it is conveyed using an air flow of powdered amorphous refractory composition, and pumps a kneaded product with a large pressure loss. Is also unnecessary.
(2) In the conventional wet spraying method, since the irregular refractory composition is transported in the form of clay, the transport distance from the supply destination to the spraying point is about 100 mm in the horizontal distance and about 60 m in the high place. However, in the present invention, since the amorphous refractory composition and the construction water are mixed in the transport pipe, there is no fear of clogging in the transport pipe, and long distance transport of about 200 m or high place up to about 150 m. Made possible.
(3) Since the quick-setting agent is also included in the irregular refractory composition, it is not necessary to perform equipment for adding the quick-setting agent in the middle of the transport pipe or to control the setting.
(4) Since there is no adhesion of the irregular refractory composition to the inside of the transport pipe and there is no remaining in the transport pipe after construction, the cleaning and maintenance work is greatly reduced, and the irregular fire resistance due to the residual in the transport pipe. Material loss was significantly reduced.
(5) The obtained sprayed refractory has excellent properties that are uniform and large in strength.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not construed as being limited to the examples.

Example 1
Using the irregular refractory spraying construction apparatus 1 shown in FIG. 1 and using the powdery amorphous refractory composition having the composition shown in Table 1 as the irregular refractory composition, Air-flow conveying spray construction was performed. In addition, content is a numerical value of the mass part per 100 mass parts of amorphous refractory compositions except a dispersing agent and a retarder.

First, an amorphous refractory material mixed with refractory aggregate, refractory powder, alumina cement as a binder, a dispersant and a retarder is measured by a quantitative conveying machine 7 (Primate II (trade name) manufactured by Japan Private Co.). It transported to the air current transport device 2 (Need Gun 400 (trade name) manufactured by Japan Private Co.), and a predetermined amount of quick setting agent was added by the quick setting agent supply device 8 to the ratio shown in Table 1 during the transport. . In addition, as a material of the amorphous refractory composition, the refractory is obtained by the same operation described below for each of the case where it is used immediately after preparation (usually) and the case where it is stored at 30 ° C. for 120 days (after storage). We performed construction of.

The above-mentioned Primate II (trade name) supplies a fixed amount of an amorphous refractory composition to which an accelerating agent is added to the air current carrier 2, but its mechanism is quantitative by a supply mechanism called a screw type auger. Is cut out and supplied. During this supply, the amorphous refractory material and the quick setting agent are mixed almost uniformly.

Next, while supplying an amorphous refractory composition having a bulk density of 2.0 g / cm ^{3 to} the air flow transport device 2 in a quantity of 1 m ³ / hr continuously from the quantitative transport device 7, 5 Nm ³ / Compressed air was sent at a flow rate of min, and an amorphous refractory composition was sent into the transport pipe 3. As the transport pipe 3, a rubber hose having a length from the air flow transport machine 2 to the spray nozzle 6 of 40 m and an inner diameter of 38 mm was used.

In the conveyance pipe 3, tap water (construction water) was added at a position of 0.8 m from the tip of the spray nozzle 6 while conveying the amorphous refractory composition by airflow.

The wet-shaped amorphous refractory composition to which construction water was added was conveyed to the spray nozzle 6 and sprayed directly onto a spray panel having a length of 400 mm × width of 400 mm × thickness of 100 mm. At this time, the discharge amount of the irregular refractory composition was 2000 kg / hr, and the spraying pressure was 0.3 MPa.

(Comparative Example 1)
In Comparative Example 1, the amorphous refractory composition was sprayed by the same configuration and operation as Example 1 except that all materials were mixed in advance as the amorphous refractory composition to be used. That is, after preparing the amorphous refractory composition by mixing all the materials in advance, the spraying construction was performed immediately, and after storing the amorphous refractory composition at 30 ° C. for 120 days, the spraying construction was performed. Two constructions were performed.

(Test example)
In Example 1 and Comparative Example 1, for each case where the material was applied immediately after preparation and when the material was applied after being stored at high temperature, each of the five spray panels was created and allowed to air dry for more than one day. After that, the cut surface of the construction body was observed by cutting in the thickness direction with a cutter, and the bulk density and bending strength of the panel after drying at 110 ° C. were measured. The test results are summarized in Table 2. Showed.

* 1 Bulk density: measured in accordance with JIS R 2655.
* 2 Bending strength: measured in accordance with JIS R 2553.
* 3 Observation of cut surface: The cut surface cut in the thickness direction was visually observed, and the uneven distribution of the aggregate and the layered peeling portion (lamination) were investigated. Evaluation was performed as follows.
[Uneven distribution of aggregates]: Uneven distribution confirmed, None: Uneven distribution confirmed [Lamination]: Exfoliation part present, None: No separation part * 4 Fillability: Thickness A plurality of cut surfaces cut in the direction were visually observed and judged based on the presence or absence of minute voids.
Good: No gaps on either side, Slightly poor: Less than half of the cut surfaces have voids, Bad: Half or more of the gaps

From these results, it was found that the properties of the obtained refractory were good without deterioration even after high temperature storage of the amorphous refractory material by the construction method of the present invention.

The method for spraying an irregular refractory according to the present invention can be used for the construction of an irregular refractory by airflow conveying spray.
It should be noted that the entire content of the specification, claims, drawings and abstract of Japanese Patent Application No. 2012-080934 filed on March 30, 2012 is cited herein as the disclosure of the specification of the present invention. Incorporated.

DESCRIPTION OF SYMBOLS 1 ... Amorphous refractory composition spray construction apparatus, 2 ... Airflow conveyance machine, 3 ... Conveyance pipe, 4 ... Construction water addition means, 5 ... Construction water addition part, 6 ... Spray nozzle, 7 ... Fixed quantity conveyance machine, DESCRIPTION OF SYMBOLS 8 ... Quick setting agent supply machine, 9 ... Compressor, 20 ... Amorphous refractory material, 21 ... Powder quick setting agent, 22 ... Amorphous refractory composition, 23 ... Construction wall surface, 24 ... Construction refractory

Claims

A mixing step of adding a powder quick-setting agent to an amorphous refractory material containing a refractory aggregate, a refractory powder, a binder and a dispersing agent, immediately before airflow conveyance, and mixing it into an amorphous refractory composition;
An airflow conveying step of carrying the amorphous refractory composition in an airflow in the state of powder and feeding it from one end side of the conveying pipe into the conveying pipe and conveying it to the other end side;
A construction water addition step of adding construction water to the amorphous refractory composition being transported in the air flow transport step;
A spraying step of spraying the amorphous refractory composition to which the construction water has been added from the spray nozzle to the construction object,
An air-flow conveying spraying method for amorphous refractories, characterized by comprising:
2. The airflow conveyance type spraying construction of the amorphous refractory according to claim 1, wherein the mixing step is performed by supplying and mixing a predetermined amount of the powder rapid setting agent to the amorphous refractory material to be quantitatively conveyed. Law.
The refractory powder is an ultrafine refractory powder having an average particle diameter of 10 μm or less, the binder is alumina cement, the dispersant is a condensed phosphate, carboxylate or sulfonate, and the powder 3. The air current conveying spraying method for an amorphous refractory according to claim 1, wherein the body setting agent is an alkali metal or alkaline earth metal silicate, aluminate, carbonate or sulfate.
The method for blowing and transporting an amorphous refractory according to claim 3, wherein the refractory ultrafine powder is alumina and / or fumed silica.
5. The air current conveying type spray construction method for an irregular refractory according to claim 3 or 4, wherein the powder quick setting agent is sodium aluminate.
The contents of the refractory powder, the binder, the dispersant, and the powder rapid setting agent are 30 to 60 parts by mass, 2.5 to 20 parts by mass, and 0.03, respectively, per 100 parts by mass of the refractory aggregate. The method of spraying an air-conditioning conveying method for an amorphous refractory according to any one of claims 1 to 5, wherein the method is -1.5 parts by mass and 0.07-4.5 parts by mass.
The method for spraying an irregularly shaped refractory according to any one of claims 1 to 6, wherein the addition position of the construction water is 0.3 to 15 m upstream from the tip of the nozzle.
A refractory constructed by the air current conveying spraying method for an irregular refractory according to any one of claims 1 to 7.