JP5366240B2 - Spraying method for irregular refractories - Google Patents

Description

  The present invention relates to the construction of various metal containers and kilns such as blast furnaces, firewood, kneading cars, converters, ladle, secondary smelting furnaces, tundish, cement rotary kilns, waste melting furnaces, incinerators, and non-ferrous metal containers. The present invention relates to a method for spraying an irregular refractory in a furnace or repair.

  The method of spraying irregular refractories, especially the dry construction method, is a method of adding construction water to the spray material that is air-conveyed in a dry state in the material transport pipe from the material feeder to the spray nozzle. It is. Here, the material transport pipe refers to a hose, a pipe, and a spray nozzle for transporting a spray material to which powder or water is added from a material feeder. In this dry construction method, after the construction water is added in the material conveying pipe, the sprayed material is kneaded, but the kneading time is very short from a few seconds to a few seconds passing through the material conveying pipe. Therefore, there is a problem that the kneading effect is low as compared with a castable that is kneaded for several minutes in advance with a mixer, and it is difficult to obtain a dense construction body. Conventionally, in order to solve such a problem, a method of adding construction water from a plurality of positions has been developed.

  For example, Patent Document 1 discloses that an amorphous refractory material containing a refractory aggregate, a refractory powder, a binder, a dispersing agent, and a quick setting agent is placed in an air current in a powder state and sent to a transport pipe to flow an air flow through the transport pipe. Spraying of irregular refractory material, which is transported through the spray nozzle and sprayed through the spray nozzle after the construction water is added in multiple stages at two or more locations in the transport pipe upstream of 0.3 to 15 m from the tip of the spray nozzle The construction method is described.

  As a result, it is possible to improve the mixability between the irregular refractory material and the construction water, so that it is possible to stably discharge the spray material from the spray nozzle and reduce dust generation during the discharge, and an excellent construction body can be obtained. It is described. In addition, by adding the construction water in multiple stages in this way, the pumping loss during transportation can be reduced compared to the case where construction water is added to the transportation pipe upstream from the tip of the spray nozzle. It is described that the conveyance becomes easy and cleaning of the remaining spray material in the conveyance pipe at the end of the construction can be greatly simplified.

  Further, in Patent Document 2, a primary water injector is provided in a material conveyance pipe extending from a material supply machine to a spray nozzle and a secondary water injector is provided immediately before the spray nozzle, and the inside of the material conveyance pipe is conveyed from each water injector. A method for spraying an irregular refractory material in which water is added to the spray material to be used. The primary water injector is provided at an upstream side of the secondary water injector, and is completely separated from the primary water injector. Add 10 to 50% by mass of construction water, add the remaining construction water required for construction from the secondary water dispenser, and in the primary water dispenser, atomized water with an average particle size of 100 μm or less together with compressed air A method for spraying an amorphous refractory to be added is described.

  And according to this method, since the atomized water having an average particle size of 100 μm or less is sprayed and added to the spray material transported in the material transport pipe, the specific surface area of the water to be added is increased. In comparison, the spray material can be remarkably uniformly wetted, and therefore, a higher kneading effect can be obtained in a short time even for the spray material powder moving at high speed in the material transport pipe. In particular, the effect of more uniform wetting on fine raw material particles is great. As a result, it is described that a dense construction body with low moisture can be obtained.

JP 2006-220348 A International Publication No. 05/121676 Pamphlet

  Since the method of patent document 1 contains the binder and the quick setting agent from the beginning in the spraying material, it is in the position away from the tip especially within the range of 0.3-15m from the tip of the spray nozzle. When construction water is added, the spray material in a slurry state adheres to the inner wall of the material transport pipe during construction, so clogging is likely to occur. That is, since the spray material becomes a soft slurry suitable for spraying downstream from the addition position of the construction water, the slurry adheres to the inner wall of the material transport pipe. Since this slurry becomes hard due to the rapid setting action of the rapid setting agent, the slurry is solidified in the material conveying pipe, and these are deposited and eventually clog the material conveying pipe.

  Therefore, in order to prevent clogging, the amount of construction water added must be increased to lower the viscosity of the kneaded material (slurry). However, if the amount of construction water added increases, the conveyance resistance increases, so the amount of conveyance air needs to be increased, resulting in an increase in rebound loss. As a result, there is a problem that it is difficult to obtain a dense construction body. Furthermore, simply adding construction water into the material transport pipe makes it difficult to uniformly knead the water and the powder material during a single hour transport, and the water is inevitably excessive.

  In the method of Patent Document 2, the construction water is added as atomized water of 100 μm or less, and 10 to 50 mass% of the construction water is added in advance from the primary water injector on the upstream side, and uniformly mixed. Therefore, the amount of construction water added is smaller than that of the method of Patent Document 1, and the increase in the amount of transported air is minimized and the rebound loss is reduced. In the case of containing an agent, there is a problem similar to that of Patent Document 1 to some extent. Moreover, in order to further extend the durability of the construction body, a construction method that can be constructed with a lower moisture content and obtain a dense construction body is required.

  An object of the present invention is to use a spraying material containing a binder and a quick setting agent, and to spray an irregular refractory material in which atomized water of 100 μm or less is added together with compressed air from a plurality of positions in the material transport pipe. In the method, a denser construction body can be obtained, and the spraying method for the amorphous refractory can be provided which avoids the adhesion of the spray material into the material transport pipe and has little rebound loss.

  The present invention uses a spraying material containing a binder and a quick setting agent, and is provided with a primary water injector and a secondary water injector in order from the upstream side in the material transport pipe from the material feeder to the spray nozzle. In the primary water injection device and the secondary water injection device, in the spraying method for the irregular refractory, the atomized water having an average particle size of 100 μm or less is added together with the compressed air. A third irrigation device is installed at a position of 0.3m to 2.0m upstream from the tip, and 1 to 30% by mass of construction water is added from the third irrigator for spraying an irregular refractory. Is the method.

  In addition, the secondary water injector is provided at a distance of 0.5 m or more upstream from the tertiary water injector in the range of 1.5 to 10 m from the tip of the spray nozzle, and the primary water injector is further upstream from the secondary water injector. An indeterminate form in which 40 to 85% by mass of construction water is added from the secondary water dispenser and 10 to 40% by mass of construction water is added from the primary water dispenser. It is a refractory spraying method.

  In this invention, since the conveyance distance in a slurry state becomes short by adding construction water at the front end side of a material conveyance pipe | tube with a tertiary water injector, adhesion to the inside of a material conveyance pipe | tube can be prevented. Therefore, the addition of construction water for reducing the viscosity of the slurry can be minimized, and the pressure resistance can be reduced and the amount of transported air can be suppressed. As a result, the supply rate of the spray material is maintained at an appropriate level, and rebound loss during construction is reduced, and a dense construction body with low moisture is obtained. And since the material conveyance pipe | tube downstream from a tertiary water injector is short, even if it is clogged downstream from a tertiary water injector, it can replace | exchange easily. Also, cleaning after replacement is easy.

  Moreover, in this invention, since the atomized water with an average particle diameter of 100 micrometers or less is added with compressed air in the primary water injector and the secondary water injector, the spray material is uniformly kneaded with water. For this reason, it becomes a uniform slurry only by adding a small amount of water with a tertiary water injector. For this reason, even if the position of the water injector is short from the tip, kneading in the nozzle will not be insufficient. Therefore, even when water is added on the tip side of the nozzle, kneading does not become insufficient, and the construction water is less than that in the past, and a dense construction body without quality variation can be obtained.

  The tertiary water injector is provided in the range from 0.3 m to 2.0 m upstream from the tip of the spray nozzle, preferably from 0.5 m to less than 1.0 m. When the position of the tertiary water injector exceeds 2.0 m from the nozzle tip, the amount of the spray material attached to the material transport pipe on the downstream side of the tertiary water injector increases. When the position of the tertiary water injector is less than 0.3 m upstream from the tip of the spray nozzle, the mixing of the construction water becomes uneven, rebound loss occurs, and the quality of the construction body deteriorates. Moreover, the addition amount of the construction water in a tertiary water injector is 1-30 mass% of all construction water, More preferably, it is 5-25 mass%. If the amount is less than 1% by mass, the amount of the spray material attached to the material conveying pipe increases, and if it exceeds 30% by mass, the amount of added water is too much for the conveying distance, making it difficult to mix water uniformly and increasing the rebound loss.

  The secondary water injector is preferably provided at a distance of 0.5 m or more upstream from the tertiary water injector and in the range of 1.5 to 10 m from the tip of the spray nozzle. When the upstream side is less than 0.5 m from the tertiary water injector, the spray material to which the construction water is added from the secondary water injector is not sufficiently kneaded. If the distance is less than 1.5 m from the tip of the spray nozzle, the kneading effect is insufficient, and the construction body tends to be non-uniform. If the distance exceeds 10 m, the amount of spray material adhering to the material transport pipe increases.

  In the secondary water injector, it is preferable to add 40 to 85% by mass of the total construction water. If it is less than 40% by mass, the kneading effect is insufficient and the construction body tends to be non-uniform, and if it exceeds 85% by mass, the amount of sprayed material adhering to the material conveying pipe increases.

  The primary water injector is preferably provided on the upstream side at a distance of 5 m or more from the secondary water injector. If it is less than 5 m, the kneading effect during conveyance of the spray material will be insufficient. In the primary water injector, it is preferable to add 10 to 40% by mass of the total construction water. If the amount is less than 10% by mass, the amount of moisture is too small and the kneading effect is insufficient.

  Further, in the present invention, as a binder for the refractory raw material powder, one or more of alumina cement, magnesia cement, phosphate and silicate, a rapid setting agent, a dispersing agent, and a fiber are mixed. In the refractory raw material powder, the raw material having a particle size of less than 75 μm is contained in an amount of 25 to 60% by mass. Among these, the mass ratio of the raw material of less than 10 μm and the raw material of less than 75 μm and 10 μm or more (less than 10 μm A spraying material having a raw material) of 0.25 to 0.7 can be used. When the amount of the raw material less than 75 μm is less than 25% by mass, it is difficult to obtain a dense construction body, and when it exceeds 60% by mass, the durability of the construction body decreases.

  Furthermore, the refractory raw material powder is made by adding and mixing one or more of a thermosetting organic resin, phosphate and silicate as a binder, and a quick setting agent. 10-45 mass% of raw materials less than 75 micrometers are contained, The mass ratio (raw material less than 10 micrometers / raw material less than 75 micrometers 10 micrometers or more of less than 10 micrometers) of raw materials less than 10 micrometers and 10 micrometers or more of these is 0.25-0. A spray material of 7 can be used. When the amount of the raw material less than 75 μm is less than 10% by mass, it is difficult to obtain a dense construction body, and when it exceeds 45% by mass, the durability of the construction body decreases.

  In the present invention, since the construction water is added in the primary water injector and the secondary water injector under the condition that atomized water of 100 μm or less is generated, the wetting effect is very high. Therefore, in order to effectively add construction water while suppressing dissolution and diffusion of the quick setting agent, an ultrafine raw material with a large specific surface area of less than 10 μm is effective, and a balance with a raw material of less than 75 μm and 10 μm or more is important. It is. That is, the mass ratio (raw material of less than 10 μm / raw material of less than 75 μm and 10 μm or more) is preferably in the range of 0.25 to 0.7, and the range of 0.30 to 0.60 is more dense. Is more preferable. If it is less than 0.25, the kneaded product tends to agglomerate and a large amount of construction water is required, and if it exceeds 0.7, the powder tends to adhere to the material conveying tube.

  In the present invention, it is possible to suppress the adhesion of the spray material to the inside of the material transport pipe, and there is little rebound loss, and a dense construction body with low moisture can be obtained.

The whole structure of the apparatus for enforcing the spray construction method of the irregular refractory of this invention is shown.

  In the present invention, the atomized water having an average particle size of 100 μm or less added from the primary water injector and the secondary water injector is obtained by making the water mist with compressed air. For example, the method of the said patent document 2 is employable.

  In the present invention, the average particle diameter of atomized water is 100 μm or less, preferably 70 μm or less, and more preferably 5 to 50 μm. This average particle diameter can be measured by a laser Doppler method. When the average particle size of the atomized water is larger than 100 μm, the specific surface area of water becomes small and the spray material becomes difficult to be uniformly moistened, and the water content varies depending on the location of the kneaded spray material. come. As a result, the amount of construction water increases in order to obtain a spray material having good workability.

  It does not specifically limit about the form of the construction water added from a tertiary water injection device, The conventional addition method can be employ | adopted, for example, you may add only water from a water ring. Further, by adding atomized water having an average particle size of 100 μm or less together with compressed air, the kneading effect can be further enhanced and a high-quality construction body can be obtained.

  Furthermore, in this invention, it is also possible to provide two or more primary water injectors. There are no particular problems even if two primary water injectors are provided at certain intervals and the primary construction water is added in two places.

  As a spray material used for the construction method of the present invention, a powder material containing a binder and a quick setting agent in a powder state can be used. There is a method of adding the quick setting agent separately in liquid or powder form before the spray nozzle, but in the construction method of the present invention, the quick setting agent is used in a state of being mixed with other raw materials in a powder state. For this reason, it is not necessary to manage the addition amount of the quick setting agent separately at the construction site, and no labor is required.

  As the binder, one or more of alumina cement, magnesia cement, thermosetting organic resin, phosphate and silicate can be used. When the temperature of the construction body is 600 ° C. or lower, alumina cement is more preferable because the strength is easily developed. Moreover, when the temperature of a construction body exceeds 600 degreeC, 1 or more types are more preferable among a thermosetting organic resin, a phosphate, and a silicate. A phenol resin or a furan resin can be used as the thermosetting organic resin.

The rapid setting agent causes the slurry to coagulate in the presence of construction water, or further reacts with the binder to rapidly cure the amorphous refractory, thereby imparting adhesion to the amorphous refractory. The quick setting agent is mixed in the amorphous refractory in the powder state from the beginning. Specific examples of the quick setting agent include silicates such as sodium silicate and potassium silicate, aluminates such as sodium aluminate, potassium aluminate and calcium aluminate, sodium carbonate, potassium carbonate and sodium hydrogen carbonate. carbonates, sodium sulfate, potassium sulfate, sulfates such as magnesium _{sulfate, CaO · Al 2 O 3,} 12CaO · 7Al 2 O 3, CaO · 2Al 2 O 3, 3CaO · Al 2 O 3, 3CaO · 3Al 2 O Calcium aluminates such as ₃ · CaF ₂ , 11CaO · 7Al ₂ O ₃ · CaF ₂ , calcium salts such as calcium oxide, calcium hydroxide, and calcium chloride.

  The dispersant is also referred to as a peptizer and can be used without any problem as long as it is used in general amorphous refractories. Has the effect of imparting fluidity during construction of irregular refractories. Specific examples include inorganic salts such as sodium tripolyphosphate, sodium hexametaphosphate, sodium ultrapolyphosphate, acid hexametaphosphate, sodium borate, sodium carbonate, polymetaphosphate, sodium citrate, sodium tartrate, sodium polyacrylate, Examples thereof include sodium sulfonate, polycarboxylate, β-naphthalenesulfonate, naphthalene sulfonic acid, carboxyl group-containing polyether dispersant, and the like.

  As the refractory raw material powder, any refractory raw material used for general amorphous refractories can be used without any problem. For example, metal oxides, metal carbides, metal nitrides, carbons, metals and the like. In addition, if the maximum particle size of the refractory raw material powder exceeds 5 mm, separation and segle are likely to occur during conveyance after addition of construction water by the primary water injector, and the kneading effect is reduced. The following raw materials are more preferably 90% by mass or more, and still more preferably, the raw material having a particle size of 3 mm or less in the refractory raw material powder is 90% by mass or more.

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

  FIG. 1 shows the overall configuration of an apparatus 10 for carrying out the method for spraying an irregular refractory according to the present invention.

  In the same figure, 1 shows the material supply machine in which the spraying material 2 was accommodated. As long as the material supply machine 1 is generally used in spraying devices for irregular refractories and can discharge a fixed amount, any type of material such as a protector gun, a lead gun, a field cement gun, etc. can be used without any problem. it can.

  The spray material 2 in the material feeder 1 is adjusted from the material feeder 1 by a table feeder 3 whose internal pressure is adjusted by compressed air supplied into the material feeder 1 and driven by a motor M provided at the lower end. It is supplied to the transport hose 5 arranged up to the spray nozzle 4.

  Carrier air is supplied to the carrier hose 5 through the carrier air introduction point 6 of the table feeder 3, and the spray material 2 from the material feeder 1 is sprayed from the spray nozzle 4 of the carrier hose 5 to the target body 11.

  The transport hose 5 is provided with a primary water injector 7 immediately after the material feeder 1, a secondary water injector 8 downstream thereof, and a tertiary water injector 9 immediately before the spray nozzle 4. .

  The primary water injector 7 and the secondary water injector 8 spray and add atomized water to the spray material that is air-conveyed in the transport hose 5 by compressed air. As the primary water injector 7 and the secondary water injector 8, those disclosed in Patent Document 2 were used. In addition, the tertiary water injector only injects water from the water ring.

  Tables 2 and 3 show the results of performing the spraying test under the spraying conditions shown in the respective tables using the spraying device shown in FIG. Table 1 shows the raw material blending ratios of the spray materials used in Tables 2 and 3. In Table 1, magnesia raw material powder is used as the refractory raw material powder, silicate is used as the binder, and slaked lime is used as the quick setting agent. For the measurement of the particle size, a JIS standard sieve was used, and for the particle size of 74 μm or less, a scattering type particle size distribution measuring device was used. The ratio of the refractory raw material powder of each particle size to 100% by mass of the refractory raw material powder is shown by mass%.

The test conditions are as follows. The flow rate of the air for conveying the spray material is 4 Nm ³ / min, the pressure is 0.27 MPa, the flow rate of the air for conveying the atomized water in the primary water injector is 250 NL / min, and the flow rate of the air for conveying the atomized water is 30 m / min. sec, the secondary water injector was also set to the same value, the inner diameter of the material transfer pipe (transport hose 5) was 35 mm, and the original pressure of water supplied to each water injector was 0.38 MPa. At this time, when the average particle size of each atomized water was measured by the laser Doppler method in a state where only the air for supplying the spray material was supplied without supplying the spray material, 34 μm (volume average) was obtained for the primary water dispenser. The particle diameter was 40 μm (volume average particle diameter) in the secondary water injector. The measurement position is 300 mm downstream from the opening of the spray nozzle. Moreover, the product name "AEROMETRICS" of the US TSI company was used for the measuring apparatus of the particle diameter of atomization water.

  The added moisture in each water injector of Table 2 and Table 3 showed the ratio of each added moisture which occupies for 100 mass parts of all construction moisture in mass%.

  The test was performed by spraying a vertically placed metal frame (depth 40 mm, width 160 mm, length 400 mm) at a position about 1 m away in the horizontal direction, observing the spraying condition of the construction body, and at 110 ° C. The quality of the construction after drying was examined.

  Moreover, about the deposit | attachment in a material conveyance pipe, except the comparative example 1 and the comparative example 2, the amount (mass) of the deposit | attachment in the material conveyance pipe | tube downstream from a tertiary water injector is measured, and the length of 10cm of material conveyance pipe | tubes Comparison was made in terms of the amount of adhesion. In Comparative Examples 1 and 2, the amount of deposits in a 1 m spray nozzle was measured. The amount of adhering material after spraying the spray material for 5 minutes was measured, and the amount of adhering material (mass) of Comparative Example 1 was taken as 100 and displayed as an index.

  Table 2 shows the results of investigating the influence of the position of the tertiary water injector on the spray construction. In Examples 1 to 7, it can be seen that when compared with Comparative Examples 1 and 2 in which atomized water having an average particle size of 100 μm or less was added from two locations, a dense construction body with less total construction moisture was obtained. Furthermore, there is little or no rebound loss during construction, and there is little deposit in the material transport pipe.

  On the other hand, the comparative example 1 and the comparative example 2 are cases where there is no tertiary water injector, and a construction body having a high total porosity and a high apparent porosity is obtained as compared with the examples. In addition, the amount of deposits in the pipe increases, and the total construction moisture also increases. In Comparative Example 3, the position of the tertiary water injector is 0.2 m, the kneading effect is insufficient, and the apparent porosity of the construction body is high. In addition, the rebound loss is very large and not practical. The comparative example 4 is a case where the position of the tertiary water injector is 2.5 m, and the amount of deposits in the material transport pipe suddenly increases. Comparative Example 5 is a case where the position of the tertiary water injector is 3 m, and the amount of deposits in the material transport pipe is further increased. Moreover, in the comparative examples 4 and 5, since the total construction water increases, the apparent porosity of the construction body is high.

  Table 3 is the result of investigating the influence of the added water of the tertiary water injector on the spraying construction. In Examples 7 to 13, the added water in the tertiary water injector is within the scope of the present invention, there is almost no rebound loss, there are few deposits in the material conveying pipe, and a dense construction body with low moisture is obtained. ing.

  On the other hand, the comparative example 6 is a case where the added water in the tertiary water injector is 0, and the amount of deposits in the material transport pipe is increased. In Comparative Example 7, the amount of water added to the tertiary water injector is too much to increase the rebound loss, and in Comparative Example 8, the rebound loss is further increased. Further, the kneading effect is reduced, and the apparent porosity of the construction body is increased.

  Table 4 shows examples with other spray materials. In Examples 15 to 17, the added water in the tertiary water injector is within the scope of the present invention, there is almost no rebound loss, there are few deposits in the material conveying pipe, and a dense construction body with low moisture is obtained. It was.

1 Material feeder 2 Spray material 3 Table feeder
4 Spray nozzle 5 Conveying hose 6 Conveying air introduction point 7 Primary water injector 8 Secondary water injector 9 Tertiary water injector
10 spraying device 11 object

Claims (4)

Using a spraying material containing a binder and a quick setting agent, a primary water injection device and a secondary water injection device are provided in order from the upstream side in the material transport pipe from the material supply machine to the spray nozzle. In the method of spraying irregular shaped refractories in which atomized water having an average particle size of 100 μm or less is added together with compressed air in a water heater and a secondary water injector,
A tertiary water injector is provided downstream of the secondary water injector and at a position of not less than 0.3 m and not more than 2.0 m upstream from the tip of the spray nozzle, and 1 to 30% by mass of the total construction water from the tertiary water injector. A method for spraying irregular refractories to which construction water is added.   The secondary water injector is set at a distance of 0.5 m or more upstream from the tertiary water injector in the range of 1.5 to 10 m from the tip of the spray nozzle, and the primary water injector is 5 m upstream from the secondary water injector. It is provided apart from the above, and 40 to 85% by mass of construction water is added from the secondary water dispenser, and 10 to 40% by mass of construction water is added from the primary water dispenser to claim 1. The spraying method of the irregular refractory described.   The spray material is added to the refractory raw material powder as a binder with at least one of alumina cement, magnesia cement, phosphate and silicate, quick setting agent, dispersant and fiber added and mixed. The raw material having a particle size of less than 75 μm is contained in the refractory raw material powder in an amount of 25 to 60% by mass, and the mass ratio of the material less than 10 μm and the material less than 75 μm and 10 μm or more (less than 10 μm / less than 75 μm / less than 10 μm The raw material) is 0.25 to 0.7. The method for spraying an irregular refractory according to claim 1 or 2.   The spray material is made by adding and mixing one or more of thermosetting organic resin, phosphate and silicate as a binder to the refractory raw material powder and the quick setting agent. 10 to 45% by mass of a raw material having a particle size of less than 75 μm, of which a mass ratio of a raw material of less than 10 μm and a raw material of less than 75 μm and 10 μm or more (raw material of less than 10 μm / raw material of less than 75 μm and 10 μm or more) is 0.25. It is -0.7. The spray construction method of the irregular refractory according to claim 1 or claim 2.

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