Spraying method for fire resistive covering material

Abstract

To provide a spraying method for fire resistive covering material that can reduce an environmental load while securing fire resistance.SOLUTION: A spraying method for fire resistive covering material uses a spraying device 1 for fire resistive covering material which comprises a spraying gun 4, a rock wool supply device 6 which supplies rock wool to the spraying gun 4, and a cement slurry supply device 8 which supplies cement slurry to the spraying gun 4, and includes: discharging rock wool from a rock wool discharge port 2 of a spraying gun 4; discharging cement slurry from a nozzle 3 of the spraying gun 4; and mixing and blowing the rock wool and cement slurry as a fire resistive covering material to an object. The cement used for the cement slurry is Portland blast furnace cement.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fireproof coating material spraying method in which a fireproof coating material made of a mixture of rock wool and cement slurry is sprayed onto an object. [Background technology]

[0002] Conventionally, fireproof coating methods for building construction include the spraying method, the wrapping method, the molded plate method, and the painting method. Among these methods, the semi-dry rockwool spraying method is a representative spraying method. This semi-dry rockwool spraying method is a method in which rockwool is mixed with cement slurry and sprayed onto the target object as a rockwool composition (see Patent Document 1). Here, the cement slurry is a mixture of ordinary Portland cement and water. This method has the advantages of being applicable to complex structures, being able to apply the method over a wide area by hose pressure feeding, making the application highly efficient, and being inexpensive. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-70546 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the semi-dry sprayed rock wool mentioned above does not use CO2 for the production of cement slurry. 2 One issue is that the use of ordinary Portland cement, which has high emissions, results in a high environmental impact.

[0005] In view of the above problems, the present invention aims to provide a method for spraying a fire-resistant coating material that can reduce the environmental load while ensuring fire resistance. [Means for solving the problem]

[0006] The first invention relates to a fireproof coating material spraying method, which uses a fireproof coating material spraying device (e.g., a fireproof coating material spraying device 1 described later) including a spray gun (e.g., a spray gun 4 described later), a rock wool supplying device (e.g., a rock wool supplying device 6 described later) that supplies rock wool to the spray gun, and a cement slurry supplying device (e.g., a cement slurry supplying device 8 described later) that supplies cement slurry to the spray gun, to discharge rock wool from a rock wool discharge port (e.g., a rock wool discharge port 2 described later) of the spray gun and discharge cement slurry from a slurry discharge port (e.g., a nozzle 3 described later) of the spray gun, mix the rock wool and the cement slurry, and spray the mixture onto an object as a fireproof coating material, characterized in that the cement used in the cement slurry is blast furnace cement.

[0007] According to this invention, by using blast furnace slag cement as the cement for the fireproof coating material instead of ordinary Portland cement as in the past, it is possible to secure fire resistance while preventing the CO 2 By reducing emissions, low carbonization can be achieved and the burden on the environment can be reduced. For example, the inventory data list by cement type in the "Summary of LCI Data for Cement" (published by the Japan Cement Association on February 16, 2023, p. 8) lists the CO 2 The CO emissions from blast furnace cement type B are 788.6g / kg. 2 It has been shown that the CO emissions from the cement used in fireproof coating materials is 458.1g / kg. Therefore, when blast furnace cement is used for fireproof coating materials, the CO emissions from the cement used in fireproof coating materials are 458.1g / kg. 2 Emissions can be reduced by around 42%.

[0008] The second aspect of the present invention is a method for spraying a fire-resistant coating material, wherein the cement slurry discharge ports of the spray gun are arranged in plurality around the rock wool discharge port.

[0009] According to this invention, a ring gun is formed in which multiple cement slurry discharge outlets are arranged around the rock wool discharge outlet, so that the rock wool discharged from the rock wool discharge outlet is enveloped by the cement slurry discharged from the cement slurry discharge outlet, thereby reducing rock wool dust generated during the spraying operation of the fire-resistant coating material. In addition, when using a ring gun, by increasing the ratio of cement slurry to rock wool, the amount of cement slurry that envelops the rock wool increases, thereby further reducing rock wool dust generated during the spraying work of the fire-resistant coating material.

[0010] In the third invention, the method for spraying a fire-resistant coating material is characterized in that the direction in which the cement slurry is discharged from the cement slurry discharge port of the spray gun is inclined by 5° to 12° toward the rock wool discharge port side with respect to the direction in which the rock wool is discharged from the rock wool discharge port.

[0011] According to this invention, the direction of discharging the cement slurry is inclined at an angle of 5° to 12° toward the rock wool discharge port side with respect to the direction of discharging the rock wool. Therefore, the discharged cement slurry holds the discharged rock wool inward to prevent it from spreading out around, so that the dust generated during the spraying work of the fireproof coating material can be further reduced.

[0012] In the fireproof coating material spraying method of the fourth invention, the ratio of the blending amounts of blast furnace cement and rock wool in the fireproof coating material is 0.4 or more and 2.4 or less in terms of solid content mass ratio.

[0013] According to this invention, by setting the ratio of the amount of blast furnace cement to rock wool in terms of solid content mass ratio to be 0.4 or more and 2.4 or less, the Portland cement normally used in fireproof coating materials can be simply converted into CO 2 Because it has better fire resistance than blast furnace cement, which can reduce emissions, it is possible to reduce the thickness of the fireproof coating material. Effect of the Invention

[0014] According to the present invention, a method for spraying a fire-resistant coating material can be provided, which can reduce the environmental load while ensuring fire resistance. [Brief description of the drawings]

[0015] [Figure 1] 1 is a schematic diagram of a fire-resistant coating material spraying device according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of a spray gun of a fire-resistant coating material spraying device. [Diagram 3] FIG. 2 is a vertical cross-sectional view of the spray gun. [Figure 4] FIG. 1 is a diagram showing the test results of a heating test of a fire-resistant coating material. [Diagram 5] FIG. 1 is a diagram showing the test results of a confirmation test of sprayability and workability using a gun. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The fire-resistant coating material spraying method of the present invention is a fire-resistant coating material spraying method in which a fire-resistant coating material spraying device including a spray gun, a rock wool supplying device that supplies rock wool to the spray gun, and a cement slurry supplying device that supplies cement slurry to the spray gun is used to discharge rock wool from a rock wool outlet of the spray gun and a cement slurry from a cement slurry outlet of the spray gun, and the rock wool and the cement slurry are mixed and sprayed onto an object as a fire-resistant coating material, characterized in that the cement used in the cement slurry is blast furnace cement.

[0017] The spraying material used in the spraying method of the present invention is composed of a mixed slurry of rock wool, blast furnace cement, and water. The ratio (C / RW) of the amount of the blast furnace cement (C) and the amount of the rock wool (RW) is preferably 0.4 or more and 2.4 or less in terms of density and fire resistance. If the ratio (C / RW) of the amount of the mixture is less than 0.4, the density is low, the fire resistance is reduced, and the strength is low, so there is a risk of falling off after spraying. In addition, if the ratio (C / RW) exceeds 2.4, the density becomes too high, so that although the fire resistance can be ensured, the amount of material used increases, and the environment is burdened. Furthermore, the nozzle becomes easily clogged, and the workability becomes poor. The ratio (C / RW) of the amount of the mixture is preferably in the range of 0.4 to 2.4, more preferably 0.6 to 2.0, and even more preferably 1.2 to 1.9.

[0018] The ratio of water to 100 parts by mass of solids in the fireproof coating material of the present invention is 60 parts by mass or more and 110 parts by mass or less from the viewpoints of workability, initial adhesion, and suppression of dust during work. If it exceeds 110 parts by mass, the water content is too high, so initial adhesion cannot be obtained, slippage occurs on the steel frame surface during spraying, workability is deteriorated, and the loss of cement slurry increases, resulting in more waste and a high environmental load. In addition, if it is less than 60 parts by mass, the water content decreases and the amount of floating dust increases. Furthermore, the amount of blast furnace cement increases, so the density increases, increasing the amount of material used and increasing the environmental load. The ratio of water to 100 parts by mass of solids in the fireproof coating material is preferably 60 parts by mass or more and 110 parts by mass or less, more preferably 65 parts by mass or more and 90 parts by mass or less.

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a rock wool spraying device 1 according to one embodiment of the present invention. The rock wool spraying device 1 includes a spray gun 4 provided with a rock wool outlet 2 for discharging rock wool and a nozzle 3 as a cement slurry outlet for discharging cement slurry, a rock wool supplying device 6 for supplying rock wool to the spray gun 4 via a rock wool supply pipe 5, and a cement slurry supplying device 8 for supplying cement slurry to the spray gun 4 via a cement slurry supply pipe 7.

[0020] Fig. 2 is a perspective view of the spray gun 4. Fig. 3 is a vertical cross-sectional view of the spray gun 4. The spray gun 4 includes a cylindrical rock wool discharge part 10 and an annular cement slurry discharge part 20 provided around the outer periphery of the rock wool discharge part 10 . A rock wool supply pipe 5 extending from a rock wool supply device 6 is connected to the base end side of the rock wool discharge part 10. The tip of the rock wool discharge part 10 forms a rock wool discharge port 2. The rock wool discharge part 10 discharges the rock wool supplied through the rock wool supply pipe 5 from the rock wool discharge port 2. The discharge direction P of the rock wool discharge port 2 corresponds to the central axis of the rock wool discharge part 10, as shown in FIG.

[0021] An internal space 21 is formed in the cement slurry discharge part 20. A connection part 22 communicating with the internal space 21 is provided on the base end side of the cement slurry discharge part 20, and the cement slurry supply pipe 7 extending from the cement slurry supply device 8 is connected to this connection part 22. Four nozzles 3 are provided at equal intervals along the periphery of the tip of the cement slurry discharge part 20, and the nozzles 3 communicate with the internal space .

[0022] The cement slurry discharge unit 20 discharges the cement slurry supplied from the cement slurry supply device 8 from the nozzle 3. The discharge direction Q of the nozzle 3 is inclined at an angle θ toward the rock wool discharge port 2 side with respect to the discharge direction P of the rock wool discharge port 2, as shown in FIG. 3. This inclination angle θ is preferably 5° or more and 12° or less. If the inclination angle is less than 5°, the intersection of the cement slurry discharged from the nozzle 3 is too far from the rock wool discharge port 2, so that the rock wool and the cement slurry cannot be mixed sufficiently, and the rock wool discharged from the rock wool discharge port 2 cannot be sufficiently wrapped, and floating dust is generated. If the inclination angle exceeds 12°, the intersection of the cement slurry discharged from the nozzle 3 is too close to the rock wool discharge port 2, so that the rock wool cannot be sufficiently wrapped, and floating dust is generated. The inclination angle θ of the discharge direction Q of the nozzle 3 is preferably 5° or more and 12° or less, more preferably 8° or more and 9° or less.

[0023] In the fire-resistant coating material spraying device 1, rock wool is supplied to the spray gun 4 by the rock wool supplying device 6, and cement slurry is supplied to the spray gun 4 by the cement slurry supplying device 8. Then, rock wool is discharged from the rock wool discharge port 2 of the spray gun 4, and cement slurry is discharged from the nozzle 3 of the spray gun 4. The rock wool and cement slurry are mixed and sprayed onto the target object as the fire-resistant coating material.

[0024] The amount of rock wool and cement slurry discharged from the spray gun is preferably 2 kg or more and 17 kg or less per 30 seconds in terms of the total amount of rock wool and cement slurry, in order to efficiently apply the material using the rock wool supply device 6 and the cement slurry supply device 8. By setting the amount of discharge within this range, the mixing ratio of rock wool and cement slurry and the concentration of cement slurry can be set in an appropriate range for spray application, and the generated dust can be suppressed, reducing the load on the spraying work environment and further suppressing the increase in size of the supply device. The total amount of rock wool and cement slurry is more preferably 5 kg or more and 11 kg or less, and even more preferably 6 kg or more and 10 kg or less.

[0025] [Sprayed rock wool heating test] In this heating test, rock wool was sprayed onto one side of the object to form a coating, and this coating was then heated as a test specimen (single-sided heating test).

[0026] FIG. 4 shows the results of the heating test. As shown in Figure 4, six specimens, No. 1 to No. 6, were manufactured. For specimens No. 1, No. 2, No. 4, and No. 5, blast furnace slag cement was used as the cement, and for specimens No. 3 and No. 6, ordinary Portland cement was used as the cement. The coating thickness was determined assuming a fire resistance of one hour for specimens No. 1 to No. 3, and three hours for specimens No. 4 to No. 6. The thickness and density of the resulting test specimen (coating) were measured. In addition, the test specimen was heated, and the maximum temperature of the test specimen and the time required to reach this maximum temperature (attainment time) were measured. Figure 4 shows that the maximum temperatures were almost the same for the test specimens using blast-furnace cement and those using ordinary Portland cement, ensuring equivalent heat insulation performance. In this way, even when blast-furnace cement is used and rock wool is sprayed, it is possible to obtain the same heat insulation performance as when ordinary Portland cement is used and rock wool is sprayed, and it is clear that blast-furnace cement, which has a low environmental impact, can be used.

[0027] [Confirmation test of sprayability and workability using a gun] In this confirmation test, the rock wool and cement slurry were sprayed onto the target object using a gun, and the sprayability and workability were visually confirmed. This time, the confirmation test was conducted four times. A ring gun or a center gun was used as the gun. The ring gun is a gun according to the present invention. With a ring gun, rock wool is discharged from the center of the gun, and cement slurry is discharged from the periphery of the rock wool outlet. The center gun is a spray gun in which the cement slurry outlet is located on the central axis of the rock wool pipe. The nozzle of the ring gun was inclined 8.5° toward the rock wool outlet with respect to the direction of the rock wool outlet. The cement slurry concentrations were two types, 42.9% and 45.5%, but the ratio of the rock wool to the cement slurry (C / RW) was kept constant at 1.50 by adjusting the discharge rate.

[0028] Figure 5 shows the results of this confirmation test. As shown in Figure 5, compared to the center gun, the ring gun was able to reduce deviation from the target and suppress the scattering of cement slurry, regardless of the cement slurry concentration, and also reduced airborne dust. This is thought to be because the rock wool is surrounded by cement slurry. It was also found that a lower cement slurry concentration can suppress airborne dust because the cement slurry spreads.

[0029] According to this embodiment, the following effects are obtained. (1) The cement used for the sprayed rock wool is not ordinary Portland cement as in the past, but blast furnace slag cement. This ensures fire resistance while preventing CO 2 By reducing emissions, low carbonization can be achieved and the burden on the environment can be reduced. (2) Since multiple nozzles 3 are arranged around the rock wool discharge port 2, the rock wool discharged from the rock wool discharge port 2 is enveloped from all sides by the cement slurry discharged from the nozzles 3, thereby reducing the rock wool dust generated during the rock wool spraying operation. (3) The direction of the cement slurry discharge is inclined by 5° to 12° toward the rock wool discharge port side with respect to the direction of the rock wool discharge. As a result, the discharged cement slurry prevents the discharged rock wool from spreading to the surroundings, further reducing the amount of dust generated during the rock wool spraying work. (4) By setting the mixing ratio of blast-furnace slag cement to rock wool at a solid content mass ratio of 0.4 to 2.4, the resulting fire-resistant performance is superior to that obtained by simply replacing portland cement with blast-furnace slag cement, thereby enabling the thickness of the fire-resistant coating material to be reduced.

[0030] The present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of the present invention that can achieve the object of the present invention are included in the present invention. For example, in the above embodiment, the number of nozzles 3 is four, but the number is not limited to four, and may be three or six. In addition, in the above-described embodiment, the inclination angle θ of the ejection direction Q of all four nozzles 3 is set to be greater than or equal to 5° and less than or equal to 12°, but it is also possible that the inclination angle θ of the ejection direction Q of only some (one or more, not all) nozzles is set to be greater than or equal to 5° and less than or equal to 12°. [Explanation of symbols]

[0031] 1... Rock wool spraying device 2... Rock wool outlet 3...Nozzle (cement slurry outlet) 4...Spray gun 5...Rock wool supply pipe 6...Rock wool supply device 7...Slurry supply pipe 8...Cement slurry supply device 10... Rock wool discharge section 20... Cement slurry discharge section 21... internal space 22... connection part

Claims

1. A fireproof coating material spraying method using a fireproof coating material spraying device including a spray gun, a rock wool supplying device that supplies rock wool to the spray gun, and a cement slurry supplying device that supplies cement slurry to the spray gun, in which rock wool is discharged from a rock wool discharge port of the spray gun and cement slurry is discharged from a cement slurry discharge port of the spray gun, the rock wool and the cement slurry are mixed, and sprayed onto an object as a fireproof coating material, A method for spraying a fireproof coating material, wherein the cement used in the cement slurry is blast furnace cement.

2. The method for spraying a fire-resistant coating material according to claim 1, characterized in that a plurality of the cement slurry discharge ports of the spray gun are arranged around the rock wool discharge port.

3. The spraying method for fire-resistant coating material according to claim 1 or 2, characterized in that the direction in which the cement slurry is discharged from the cement slurry discharge port of the spray gun is inclined toward the rock wool discharge port by 5° to 12° with respect to the direction in which the rock wool is discharged from the rock wool discharge port.

4. 2. The method for spraying a fireproof coating material according to claim 1, wherein the ratio of the amount of blast furnace cement to the amount of rock wool in the fireproof coating material is 0.4 or more and 2.4 or less in terms of solid content mass ratio.

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