JP2004245574A - Spray construction method for monolithic refractory - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce load on workers and increase working efficiency by reducing the porosity of a construction body, increasing bulk density, and reducing environmental pollution in spraying in the spray construction of monolithic refractory. <P>SOLUTION: Water is applied to powder compound for monolithic refractory including fire resistant aggregates, fire resistant powder, and small amount of dispersing agent and kneaded by a mixer 1 to provide kneaded soil. Next, the soil is thrown into the hopper of an air carrying apparatus 3 having a conduit leading the soil thrown into the hopper into a pocket group positioned on the underside, a vibrator providing vibration to the soil, the rotating pocket group, and a high-pressure air blowing tube to discharge the soil in pockets through a discharge tube by the blowing of high-pressure air. The soil discharged from the air carrying apparatus 3 is air-carried through the inside of a transportation tube 5 having a tip part connected to a spray nozzle 8, a specified amount of an accelerating agent is injected into the carried soil from an accelerating agent filling port, and spray construction is performed by using the spray nozzle 8. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a method for spraying an irregular-shaped refractory for constructing an irregular-shaped refractory having a large strength and a large specific gravity.

  The spraying of irregular-shaped refractories has the advantage that labor can be saved in comparison with the casting method that requires a formwork.Therefore, the conventional method of spraying irregular-shaped refractories has been implemented. ing.

  The conventional spraying method is a so-called dry spraying method, in which a dry, non-flowable dry amorphous refractory powder composition is conveyed to a construction site using compressed air as a carrier by piping or a rubber hose, and sprayed by a spray nozzle. Moisture required by irregular-shaped refractories is injected and sprayed from a spray nozzle.

  However, in such a method, finely dispersed in the kneaded clay of the amorphous refractory powder composition, for example, 0.1 mm or less the dispersion state and the wetting of the particles of the refractory powder to be sprayed in an insufficient state is performed. However, a lot of air is taken into the clay of the sprayed irregular-shaped refractory, and as a result, the porosity of the sprayed irregularly-shaped refractory construction body is larger and more bulky than that of the cast construction. Since the specific gravity was small, refractory performance such as corrosion resistance was inferior.

  On the other hand, after the necessary amount of water to be originally added by the spray nozzle is added and kneaded to the powder composition for the amorphous refractory for dry spraying in advance, the compressed air is used as a carrier and piping or a rubber hose is used to bring air to the work site. It is also known to carry out wet spraying by spraying with a spray nozzle.However, a mixture obtained by adding water to the powder composition for an amorphous refractory for dry spraying and kneading the same is to remove dripping after spraying. In order to prevent this, it is essential to include a component such as clay that increases the viscosity of the clay and a component that rapidly increases the viscosity by shortening the setting time of the alumina cement, and as a result, the viscosity of the clay is Has become too large, causing problems such as pulsation at the time of pneumatic conveyance and significant blockage in the piping.

  As a means for avoiding these problems, a method of spraying irregular-shaped refractories described in Japanese Patent Application No. Hei 8-116621 has been proposed. This method is useful as such, but has the following problems. I was

  That is, the self-fluidizing clay obtained by adding water to the amorphous refractory powder composition and kneading the mixture is sent to the spray nozzle by a pressure pump, and a compressed air injection port provided in front of the spray nozzle and a quick setting agent injection. Injection is performed by injecting compressed air and quick-setting agent from the inlet, respectively, but if the injection amount of compressed air is excessively large, the essential amount contained in the kneaded clay of the powder composition for amorphous refractory There has been a problem that the refractory aggregate as a component is separated and scattered by a spray nozzle.

  An object of the present invention is to solve the above-mentioned problems of the prior art, to further reduce labor during construction, to reduce scattering of dust to the surroundings, to reduce the porosity of the construction body, and to reduce the bulk specific gravity. It is an object of the present invention to provide a method for spraying an amorphous refractory which is large and has excellent characteristics as a refractory.

The spraying method for an amorphous refractory according to the present invention has the following gist.
(1) Water is added and kneaded to a powder composition for an amorphous refractory containing a refractory aggregate, a refractory powder and a small amount of a dispersant,
The obtained kneaded clay was poured and filled into a truncated cone-shaped cone having an upper end inner diameter of 50 mm, a lower end inner diameter of 100 mm, and a height of 150 mm and opened at the upper and lower ends. Let it have a self-fluidity with a spreading diameter of 160 mm or more,
Next, an air carrier equipped with a conduit that guides the kneaded clay into the lower pocket group, the vibrator that vibrates the kneaded clay, a rotating circulation pocket group, and a high-pressure air blowing pipe. Put into the hopper of the device, discharge the clay in the pocket through the discharge pipe by blowing high-pressure air,
The kneaded material discharged from the air conveying device is pneumatically conveyed through a transport pipe having a spray nozzle connected to a tip thereof, and a required amount of quick-setting agent is injected from the quick-setting agent injection port into the conveyed kneaded material. And spraying with the spray nozzle.
(2) An amorphous refractory powder composition comprising a refractory powder containing a refractory aggregate, a refractory ultrafine powder having an average particle diameter of 10 μm or less composed of alumina and / or fumed silica, and a small amount of a dispersant. The method for spraying irregular shaped refractories according to the above (1).
(3) a nozzle having a nozzle pipe between a spray nozzle and a transport pipe, and injecting a quick-setting agent from a quick-setting agent inlet provided at the nozzle pipe or at a connection between the transport pipe and the nozzle pipe; The method for spraying irregular shaped refractories according to 1) or 2).
(4) The method according to any one of (1) to (3), wherein the quick-setting agent is a powder, the quick-setting agent is transported by compressed air, and the quick-setting agent is injected together with the compressed air from the quick-setting agent injection port. The method for spraying irregular shaped refractories as described.
(5) The spray of the amorphous refractory according to any one of (1) to (3), wherein the quick-setting agent is a liquid, and the quick-setting agent is transported by a liquid pump and injected through the quick-setting agent inlet. Construction method.
(6) The method of spraying irregular shaped refractories according to any one of the above (1) to (5), wherein the air conveyance comprises a defoaming step of the kneaded clay and a quantitative supply step.
(7) The kneaded clay to be conveyed by air, according to any one of the above (1) to (6), in which the material is ejected by compressed air after the defoaming step and the fixed-quantity supplying step, and passes through a straight section of a transport pipe of 200 mm or more. Spray construction method for irregular refractories.

  According to the present invention, the porosity and bulk specific gravity of the construction body of the spray-formed irregular-shaped refractory, and other physical properties are comparable to those of the construction body obtained by the conventional mold casting method, and spraying The environment is less likely to be polluted by the scattering of dust due to dust. Further, it is possible to further reduce labor, to reduce the burden on the worker, and to achieve an excellent effect that the working efficiency is remarkably improved.

  The main feature of the spraying construction method of the present invention is that the kneaded clay of an amorphous refractory having self-flowing property is pneumatically conveyed to a construction site. According to this method, the kneaded clay of the irregular-shaped refractory in which the required moisture is previously mixed is sent to the construction site by air conveyance, so that the distribution of water in the kneaded clay is performed by mixing and kneading the required moisture in advance. It can be uniform and sufficiently defoamed. In addition, spraying is performed without air being re-mixed into the kneaded material during air conveyance. As a result, a construction body of an amorphous refractory having a small porosity and a large bulk specific gravity is obtained.

  In the spraying construction method of the present invention, since the quick-setting agent is injected near the spraying nozzle connected to the tip of the transport pipe, the kneaded material sprayed from the spraying nozzle is rapidly self-generated by the injected quick-setting agent. Fluidity is reduced, and therefore, even when sprayed on a vertical wall surface or a ceiling wall surface, the clay can be applied without falling or falling off the wall surface.

  Furthermore, since the clay having self-fluidity can be rapidly kneaded at the tip of the transport pipe, the composition having a low viscosity and the hardening time are sufficiently long as the clay having self-fluidity. It is possible to select a composition that can maintain the self-fluidity for more than an hour). It has excellent features such as observable pulsation during air conveyance and obstruction in the piping, and a sound sprayed construction can be obtained after spraying.

  When injecting the quick setting agent near the spray nozzle, it may be injected from the quick setting agent injection port provided directly on the spray nozzle, but a nozzle of 100 mm or more, preferably 200 mm or more between the spray nozzle and the transport pipe If a pipe is arranged and the quick-setting agent is injected from the quick-setting agent injection port provided at the connection between the nozzle pipe or the nozzle pipe and the transport pipe, the clay and the clay are discharged before being discharged from the spray nozzle. The quick-setting agent can be uniformly mixed, and as a result, the amount of the quick-setting agent added can be reduced, and deterioration of the fire resistance performance due to unevenness of the quick-setting agent can be prevented.

  The present invention is characterized in that the air conveyance preferably includes a kneaded clay defoaming step and a quantitative supply step. As a more preferred embodiment of the defoaming step and the quantitative supply step, in a pneumatic conveying device (spraying device) provided with a rotor having a plurality of pockets, a conduit for charging the clay by its own weight into the pockets is provided. By applying vibration to the soil, air mixed into the clay during kneading can be significantly reduced. In addition, even if the clay has high viscosity to some extent, complete supply can be performed by vibrating the clay, and the quantitativeness of the air conveyance amount can be maintained even when used for a long time.

  In the air conveyance, the kneaded material is transferred using high-pressure air as a carrier, but when the supply speed of the kneaded material is not constant, the transfer pressure loss of the kneaded material fluctuates, and as a result, the air flow rate also fluctuates, and pulsation occurs. As a result, the discharge amount of the kneaded clay at the tip of the spray nozzle fluctuates, causing a problem such as an uneven structure after application.However, the air conveyance according to the present invention includes a defoaming step and a constant-quantity supply step of the kneaded kneaded clay. By doing so, it has excellent features such as the ability to avoid these problems.

  In the air conveyance after the defoaming step and the fixed-quantity supply step, the discharge resistance of the material kneaded material can be reduced by having the transport pipe straight section of 200 mm or more at the material discharge port, and the material kneaded material adheres to the transport pipe. However, it has an excellent feature that a problem such as remarkable blockage can be avoided.

  In the pneumatic conveyance of the present invention, the kneaded material is transported by using a pipe or a rubber hose, and a blow is performed by a worker who freely operates the spray nozzle as a rubber hose of about 10 m in front of the normal spray nozzle. The inside of the rubber hose portion held by the worker is very light because the clay is floating in the air, so that the working labor can be reduced.

  In the present invention, the fluidity of the clay is evaluated using a cone type. That is, at a temperature of about 20 ° C., the clay immediately after adding water at about 20 ° C. to the powder composition for an amorphous refractory and kneading the same, the upper end inner diameter is 50 mm, the lower end inner diameter is 100 mm, the height is 150 mm, and the upper and lower ends are Spread the kneaded clay immediately after kneading into an open frustoconical cone mold, fill the cone mold, withdraw the cone mold upward, and let it stand for 60 seconds (average value measured in two directions, hereinafter referred to as flow value) ).

  The kneaded clay exhibits self-fluidity if the flow value is 150 mm or more. However, in order to stably carry the air, the flow value of the clay is preferably 160 mm or more, more preferably 180 mm or more. If the clay having a large flow value is used, the resistance of air conveyance can be reduced, the diameter of the pipe or hose to be conveyed can be reduced, and long distance transportation of the clay can be realized.

  The powder composition used in the present invention contains a refractory aggregate, a refractory powder and a small amount of a dispersant. The refractory powder fills the gaps between the refractory aggregates to form a joint that joins the refractory aggregates. Examples of refractory aggregates include alumina, bauxite, diaspore, mullite, ban shale, chamotte, silica, pyrophyllite, silymanite, andalusite, chromite, spinel, magnesia, zirconia, zircon, chromia, silicon nitride, One or more selected from carbon such as aluminum nitride, silicon carbide, boron carbide and graphite, titanium boride and zirconium boride are preferred.

  Examples of the refractory powder include alumina cement, alumina, titania, bauxite, diaspore, mullite, ban shale, chamotte, pyrophyllite, sillimanite, andalusite, quartzite, chromite, spinel, magnesia, zirconia, zircon, chromia , Silicon nitride, aluminum nitride, silicon carbide, boron carbide, titanium boride, zirconium boride, and amorphous silica such as fumed silica, and preferably has an average particle size of 30 μm or less.

  In particular, in the present invention, it is preferable to use a refractory ultrafine powder made of alumina and / or fumed silica having an average particle diameter of 10 μm or less as the refractory powder. When such a refractory ultrafine powder made of alumina and / or fumed silica having an average particle size of 10 μm or less, preferably 5 μm or less is used, the amount of water added to the kneaded material can be reduced, and the kneaded kneaded material can be reduced. Good fluidity can be imparted to the soil.

  In the present invention, it is preferable to use alumina cement as a part of the refractory powder in the powder composition. In this case, the alumina cement functions as a binder for the amorphous refractory, and the construction body can maintain strength in a wide range from room temperature to high temperature.

  As a means for imparting good self-flowability to the clay, it is preferable that a powder dispersant selected according to the type of refractory aggregate and refractory powder to be used is blended in the powder composition. . The dispersant is preferably at least one selected from polymetaphosphates, polycarboxylates, polyacrylates and β-naphthalenesulfonates, and the total amount of the refractory aggregate and refractory powder of the powder composition. It is preferable to add 0.02 to 1 part by weight to 100 parts by weight.

  Moisture added to the powder composition for the amorphous refractory is based on 100 parts by weight of the powder composition so as to reduce the porosity of the applied amorphous refractory and secure good characteristics as a refractory. It is preferably 15 parts by weight or less, more preferably 12 parts by weight or less. If the water content of the kneaded clay is low, it is possible to suppress the refractory aggregate contained in the kneaded clay from settling and the kneaded clay from becoming heterogeneous. can get.

  As the quick setting agent to be injected into the kneaded material, a powder or liquid agent can be used. When a liquid quick-setting agent is used, it is not preferable to excessively increase the liquid portion (usually using water) because the denseness of the construction body after spraying is reduced.

  A device capable of uniformly controlling the amount of powder to be added can be preferably used for the transfer of the powder quick-setting admixture. Usually, a device for conveying the quick-setting admixture using compressed air as a carrier is used.

  Further, the liquid quick-setting agent is also preferably a liquid pump capable of uniformly controlling the supply amount, and it is necessary to appropriately select a liquid quick-setting agent according to the type of the quick-setting agent to be used. A plunger pump, a diaphragm pump, and the like are preferable. You.

Examples of powder quick setting agents include aluminates such as sodium aluminate, potassium aluminate and calcium aluminate, carbonates such as sodium carbonate, potassium carbonate, sodium bicarbonate and potassium bicarbonate, sodium sulfate, potassium sulfate, and the like. 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 2 · CaF 2, 11CaO · 7Al 2 O calcium aluminate such as ₃ · CaF _2, calcium oxide, one or more kinds selected from calcium hydroxide and their composite salt or mixtures can be used. In the case of a liquid quick setting agent, a solution in which the powder quick setting agent is dispersed in water or the like can be used.

  The amount of the powder quick setting agent to be injected is preferably 0.05 to 3 parts by weight on a dry basis with respect to 100 parts by weight of the total amount of the refractory aggregate and the refractory powder, that is, 0.05 parts by weight or less. In this case, the rapid setting speed is insufficient, and dripping occurs in the clay after spraying. Further, if more than 3 parts by weight is injected, there is a problem that the material is rapidly cured and spraying becomes difficult. Further, the injection amount of the liquid quick-setting admixture is preferably 0.05 to 3 parts by weight in the substantial powder quick-setting admixture before being diluted and dispersed with water or the like.

  In particular, when using a powder quick-setting admixture, bridging or deliquescence may occur during the addition process using the quick-setting additive adding device, and the plug may be clogged.In this case, when particles of the refractory powder are added, This is preferable because the discharge can be made smooth.

  Further, if the total amount of the refractory aggregate and the refractory powder is 100 parts by weight, and if 0.003 to 0.2 parts by weight of a curing retarder is added, the pot life of the kneaded clay is in a preferable range of 2 to 2. It can be extended up to about 6 hours, ensuring a sufficient pot life even in summer when the temperature is high, so that refractory can be sprayed stably. Weak acids such as oxalic acid, boric acid, malic acid and citric acid can be preferably used as the curing retarder.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In Table 1, Examples 1 to 6 show spraying examples of the present invention, Examples 7 to 9 show casting comparative examples, and Example 10 shows spraying comparative examples.

(Examples 1 to 6)
In Examples 1, 2 and 4, 5, 6, the content of Al ₂ O ₃ , SiO ₂ and Fe ₂ O ₃ as the refractory aggregate was 43% by weight, 53% by weight and 0.9% by weight, respectively. Using a chamotte aggregate consisting of coarse particles with a particle size of 1.68 to 5 mm, medium particles with a particle size of 0.1 to 1.68 mm, and fine particles with a particle size of 0.02 to 0.1 mm and an average particle size of 0.03 mm In No. ₃ , the contents of Al ₂ O ₃ , SiO ₂ and Fe ₂ O ₃ are 89% by weight, 7% by weight and 1.3% by weight, respectively. Bauxite aggregate consisting of medium grains of 1.68 mm and fine grains having a grain size of 0.02 to 0.1 mm and an average grain size of 0.02 mm was used.

As the refractory powder constituting the coupling portion of the refractory, purity 99.6 weight Al ₂ O ₃ and CaO average particle diameter 9μm alumina cement content is 55 wt% and 36 wt% each, Al ₂ O ₃ Bayer alumina having a mean particle size of 4.3 μm and fumed silica having a purity of 93% by weight of SiO ₂ and a mean particle size of 0.8 μm were used. As the dispersant, sodium tetrapolyphosphate powder containing 60.4% by weight and 39.6% by weight of P ₂ O ₅ and Na ₂ O, respectively, was used.

  The powder composition shown in (Table 1) was prepared by mixing the refractory aggregate, the refractory powder and the dispersant, and the amount of water (refractory aggregate and fire resistance) shown in (Table 1) was added to each composition. The powder was added by inner weight%, and the others were outer weight weight), and kneaded in a 500 kg vortex mixer for 3 minutes to obtain a clay. The fluidity of each kneaded clay is determined by pouring the kneaded kneaded clay into a frusto-conical cone shape having an upper end inner diameter of 50 mm, a lower end inner diameter of 100 mm, a height of 150 mm, and open upper and lower ends. The spread diameter when the sample was pulled out and allowed to stand for 60 seconds was measured with calipers in two directions, and the average value was defined as the flow value.

  In Examples 1 to 4 and 6, the powder quick-setting agent is a powder having a particle diameter of 800 μm or less and an average particle diameter of about 150 μm, and contains sodium aluminate (containing about 20% water of crystallization) and sodium carbonate. Those containing at a weight ratio of 3: 1 were used.

  In Example 5, a liquid quick-setting admixture was used, and its formulation was prepared by previously mixing and dispersing 100 parts by weight of the powder quick-setting admixture with 1000 parts by weight of water. Table 1 shows the substantial amount of the powder quick-setting additive in the liquid quick-setting admixture.

  Spraying was performed by the spraying construction apparatus shown in FIG. In other words, the air pressure is adjusted so that the distance between the spray nozzle and the iron plate is about 1000 mm, in order to use the spraying construction device of FIG. 1 to spray the wall of a vertical steel plate (without anchors) to a thickness of about 100 mm. At the same time, the spraying speed was adjusted to 4 tons / hour with the kneaded clay, and spraying was performed. The construction was performed at a temperature of approximately 20 ° C.

  In FIG. 1, 1 is a mixer, 3 is an air conveying device for kneaded material, 5 is a transport pipe, 6 is a quick-setting agent injection port, 7 is a nozzle pipe, 8 is a spray nozzle, 4 is a quick-setting agent adding device, 9 Is a quick-setting agent transport pipe, 10 is an air compressor, 11 is an air header, 12 is an air dryer, and 13, 14, 15, and 16 are air hoses.

  The kneaded clay having self-fluidity kneaded by the mixer 1 is introduced as shown by an arrow 2 into an air transport device 3 having a defoaming step and a constant-quantity supply step of the kneaded clay, and is pneumatically transported through a transport pipe 5. Further, the kneaded material conveyed by air is injected with the quick setting agent at the quick setting agent injection port 6, passes through the nozzle pipe 7, and is sprayed from the spray nozzle 8. The high-pressure air, which is the driving source of the air transfer device 3, is supplied from the air compressor 10 through the air hose 13, the air header 11, and the air hose 14.

  In this embodiment, the transport pipe 5 and the nozzle pipe 7 have a nominal diameter of 40 A, and are made of rubber hoses having lengths of 20 m and 200 mm, respectively. As the quick-setting agent injection port 6, a Y-shaped nozzle pipe whose inner diameter is substantially the same as the transport pipe 5 and the nozzle pipe 7 is used.

  In Examples 1 to 4 and Example 6, in order to quantitatively inject the powder quick-setting admixture, a quick-setting admixture adding device 4 equipped with a disk feeder (in this example, a Q gun manufactured by Nippon Pribrico Co., Ltd.) was used. The high-pressure air passed through an air dryer 12 for dehumidifying high-pressure air from an air compressor 10 through an air hose 13, an air header 11, and an air hose 15 was used as a transport source. Further, the quick-setting agent was conveyed to the quick-setting agent inlet 6 together with air from the quick-setting agent adding device 4 through a quick-setting agent transport pipe 9.

  In Example 5, a liquid quick-setting agent is used, and instead of the quick-setting agent adding device 4, the air dryer 12, and the air hose 15 in FIG. 1, a triple-type plunger pump is attached to transport the quick-setting agent. The liquid quick-setting agent was sent to the quick-setting agent inlet 6 through the pipe 9. In this case, the liquid quick-setting agent was pressure-injected by the liquid pump, but before the liquid quick-setting agent was injected into the kneaded material, high-pressure air was injected into the kneaded material to form a mist-like liquid quick-setting agent. Is also preferably carried out.

  In Example 4, the transporting pipe 5 was directly connected to the spray nozzle 8 without providing the quick-setting agent injection port 6 and the nozzle pipe 7, and the powder quick-setting agent was directly injected into the spray nozzle 8 in a state of mixing high-pressure air. did.

  FIG. 2 and FIG. 3 show a detailed configuration of the pneumatic conveying device 3 used in the present embodiment and provided with a kneaded clay defoaming step and a quantitative supply step. FIG. 3 is a diagram viewed from the direction A in FIG. 21 is a hopper for charging the clay 22, 23 is a conduit for guiding the clay downward, and the conduit 23 is provided with a vibrator 24 that vibrates so as to smoothly flow downward even in a clay with high viscosity. I have. Reference numeral 25 denotes a rotation shaft which rotates a pocket group including a plurality of pockets 26 arranged around the rotation shaft. Reference numeral 27 denotes an air blowing pipe for blowing high-pressure air into the pocket 26, to which the air hose 14 of FIG. 1 is connected. Reference numeral 28 denotes a discharge pipe for the material, and 29 denotes a support fitting for supporting the discharge pipe 28. The discharge pipe 28 has a relatively long straight portion B (in this embodiment, the linear distance is 400 mm) and a relatively gentle bend C continuously from the straight portion B. The transport pipe 5 is connected.

  In the defoaming step and the constant-quantity supply step of the present invention, a conduit 23 for charging the clay by its own weight into a plurality of rotating pockets 26 is provided, and the clay passing through the conduit 23 is vibrated by a vibrator 24 to give the clay. Eliminate air in soil. As a result, air mixing into the plurality of pockets 26 is significantly reduced, and it is possible to completely supply the clay even to a certain degree of viscosity, and it is possible to maintain the quantitativeness of the air conveyance amount even during long-time use. it can.

  In addition, since the material discharge pipe has the straight portion B of 200 mm or more, the air flow velocity of the kneaded material flowing in the straight portion becomes sufficiently large, that is, by giving kinetic energy to overcome the flow resistance in the curved portion, It has excellent features such as the ability to smoothly discharge the soil, reduce the discharge resistance, and avoid problems such as the clay sticking to the transport path and significantly blocking. Thus, the clay put into the hopper of the air conveying device is supplied by its own weight into each pocket through the conduit, and then the clay in each pocket moves to the discharge pipe side of the clay by rotation of the pocket. At this time, the kneaded clay is discharged into the transport pipe of the kneaded clay through the discharge pipe by blowing high-pressure air into the pocket.

  In the case of Example 6, the defoaming step and the quantitative supply step of the clay were performed under the following conditions. That is, the vibrator 24 in FIG. 2 was not operated, the straight section B of the discharge pipe 28 was set to 150 mm in length, and the other conditions were the same as in Example 1. Although a slight pulsation tendency was observed in the rubber hose of the transport pipe 5 during the transfer of the kneaded clay, the bulk specific gravity and the physical properties of the construction body were hardly changed as compared with the case where the casting was performed in Example 7. In the spraying work of the present invention shown in Examples 1 to 6, there is almost no rebound and no dust at the time of spraying work, and particularly no separation or scattering of the refractory aggregate at the spray nozzle tip is observed. Compared with the construction method, the construction yield and working environment were extremely good.

  The construction body sprayed to a thickness of about 100 mm on the construction wall was left in a room at approximately 20 ° C for 24 hours, and a construction body sample of about 30 cm × 30 cm was collected from each construction body, and the collected sample was heated to 110 ° C. After drying for 24 hours, the porosity and bulk specific gravity were measured according to the method specified in JIS R2205.

(Examples 7 to 10)
Examples 7 to 9 show the results obtained for the irregular shaped refractory construction bodies in which the clay of Example 1, Example 2, and Example 3 was cast into a mold having an inner size of 40 mm × 40 mm × 160 mm. The bulk specific gravity and physical properties of the refractory molded articles obtained by spraying according to the method of the present invention of Examples 1 to 3 shown in (Table 1) are almost inferior to those of Examples 7 to 9. I understand that there is no. Also, in the case where the powder quick-setting agent is directly added by the spray nozzle 8 as shown in Example 4 or the case where the liquid quick-setting agent is used as shown in Example 5, in comparison with the case where the casting is carried out in Example 7. It can be seen that the bulk specific gravity and the physical properties of the irregularly shaped refractory construction body obtained by the spraying construction of the present invention are hardly inferior.

  Example 10 is an example in which spraying is performed using a pressure feed pump instead of the air transfer device 3 in FIG. Using a double-piston pump, adjust the air pressure so that the distance between the spray nozzle and the wall is 1000 mm, and adjust the spray speed to 4 tons / hour for the kneaded clay to perform spraying. The other conditions were the same as in Example 3, but no sample was collected since rebound of the refractory aggregate was remarkably observed at the tip nozzle portion.

It is a block diagram of the spray construction equipment used in the example of the present invention. It is sectional drawing of the air conveyance apparatus of the clay in the spraying construction apparatus. FIG. 3 is a view taken along the line AA in FIG. 2.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 ... Mixer 3 Air-conveying device of kneaded material 4 ... Addition device of quick-setting agent 5 ... Conveying pipe of kneaded material 6 ... Quick-setting agent inlet 7 ... Nozzle piping 8 ... Blowing nozzle 9 ... Pipe for transport of quick-setting agent, 10 ... Air compressor, 11 ... Air header, 12 ... Air dryer, 21 ... Hopper, 22 ... Clay, 23 ... Conduit, 24 ... Vibrator, 26 ... Pocket, 27 ... Air blowing pipe, 28 ... Discharge pipe.

Claims (7)

Water is added and kneaded to a powder composition for an amorphous refractory containing a refractory aggregate, a refractory powder and a small amount of a dispersant,
The obtained kneaded clay was poured into a truncated cone-shaped cone having an upper end inner diameter of 50 mm, a lower end inner diameter of 100 mm, and a height of 150 mm, and opened at the upper and lower ends. The cone was pulled out and allowed to stand for 60 seconds. Let it have a self-fluidity with a spreading diameter of 160 mm or more,
Next, a pneumatic conveying device including the above-mentioned kneaded material, a conduit for guiding the kneaded material charged into the hopper into a lower pocket group, a vibrator for applying vibration to the kneaded material, a rotating pocket group, and a high-pressure air blowing pipe. Into the hopper, and discharge the kneaded material in the pocket through the discharge pipe by blowing high-pressure air,
The kneaded material discharged from the air transfer device is pneumatically conveyed through a transport pipe having a spray nozzle connected to a tip thereof, and a required amount of quick-setting agent is injected from the quick-setting agent injection port into the conveyed kneaded material. And spraying with the spray nozzle.   The powder composition for an amorphous refractory comprises a refractory powder including a refractory aggregate, a refractory ultrafine powder having an average particle diameter of 10 μm or less composed of alumina and / or fumed silica, and a small amount of a dispersant. 2. The method for spraying irregular shaped refractories according to 1.   3. A quick-setting agent is injected from a quick-setting agent inlet provided at a nozzle pipe or a connecting portion between the conveying pipe and the nozzle pipe, having a nozzle pipe between the spray nozzle and the transport pipe. A method for spraying irregular-shaped refractories according to the above.   The irregular-shaped refractory according to any one of claims 1 to 3, wherein the quick-setting agent is a powder, the quick-setting agent is transported by compressed air, and the quick-setting agent is injected together with the compressed air from a quick-setting agent injection port. Spraying method.   The method for spraying an irregular-shaped refractory according to any one of claims 1 to 3, wherein the quick-setting agent is a liquid, and the quick-setting agent is transported by a liquid pump and injected from a quick-setting agent inlet.   The method for spraying an irregular-shaped refractory according to any one of claims 1 to 5, wherein the air conveyance includes a defoaming step of the kneaded clay and a fixed-quantity supply step.   The kneaded clay to be air-conveyed, when discharging the material by compressed air after the defoaming step and the fixed-quantity supplying step, spraying the irregular-shaped refractory according to any one of claims 1 to 6, through a straight section of a transport pipe of 200 mm or more. Construction method.

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