Refractory coating method

Abstract

To save manpower for fireproof covering work by spraying.SOLUTION: A fireproof covering method includes: a spraying step of spraying a fireproof covering material onto a surface to be installed; a spraying step of spraying water onto the fireproof covering material; and a fireproof finishing step of applying wind pressure from an air blast to the fireproof covering material.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a fireproof coating method for carrying out fireproof coating work by spraying. [Background technology]

[0002] In steel-framed buildings, fireproofing is achieved by coating the surface of the structure with a fireproof coating material. Known methods for carrying out fireproofing by spraying include the dry method and the semi-dry method. The dry method is a method in which a mixture of premixed rock wool and cement is sprayed onto the surface to be worked on, while the semi-dry method is a method in which a mixture of rock wool and cement slurry is sprayed onto the surface to be worked on. For example, Patent Document 1 discloses a nozzle for spraying rock wool for use in the semi-dry method.

[0003] Specifically, when the cement slurry and rock wool are mixed and sprayed onto the object by separately pumping them and simultaneously spraying them from a nozzle, multiple cement slurry spray tips are arranged around the rock wool outlet. The depression angle of the cement slurry spray tips is adjusted according to the distance between the object and the rock wool outlet, forming a sprayed layer on the object.

[0004] If spraying is performed using a nozzle as disclosed in Patent Document 1, a sprayed layer can be formed efficiently, but there is a problem that rock wool that does not adhere to the cement is likely to scatter. For this reason, Patent Document 2 provides a spray nozzle with a spray section capable of spraying mist, moistening the scattered dust containing rock wool with the mist to increase its weight and prevent it from scattering to the outside.

[0005] In both Patent Document 1 and Patent Document 2, the surface of the sprayed layer may be uneven or frayed, and the sprayed layer may not adhere sufficiently to the target object. For this reason, it is mandatory to perform a fireproof finish on the sprayed layer formed on the target surface by pressing it with a trowel, as disclosed in Patent Document 3, for example. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Utility Model Application Publication No. 56-110858 [Patent Document 2] JP 2020-040020 A [Patent Document 3] JP 2018-096103 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, the trowel holding work requires manpower, and furthermore, if the surface to be worked on is at a high altitude, work at high altitudes will be required using work scaffolding, aerial work vehicles, etc. Particularly in recent years, many work sites have introduced spraying robots to reduce the labor required for spraying work and to improve work efficiency, and in such cases, manpower will need to be secured for the trowel holding work, and equipment such as work scaffolding and aerial work vehicles will need to be prepared.

[0008] The present invention has been made in consideration of the above problems, and its main object is to reduce the labor required for fireproof coating work by spraying. [Means for solving the problem]

[0009] In order to achieve the above object, the fireproof coating method of the present invention includes a spraying step of spraying a fireproof coating material onto a surface to be treated, a spraying step of spraying water onto the fireproof coating material, and a wind pressure caused by blowing air. The sprayed water is coated The fireproof covering material The surface of the fireproof coating material is pressed to suppress fuzzing and to eliminate unevenness to make it smooth. and a fire-resistant finishing process.

[0010] According to the fire-resistant coating method of the present invention, water is sprayed onto a fire-resistant coating material, and wind pressure is applied to the fire-resistant coating material through the surface of the fire-resistant coating material covered with the sprayed water. As a result, the fire-resistant coating material is pressed against the surface by being covered with the mist of water and being subjected to the wind pressure, thereby suppressing fluffing.

[0011] In addition, the wind pressure can be used to apply a pressing force to the fireproof coating material similar to that of a trowel. Therefore, by blowing air at a specified volume while moving along the surface of the fireproof coating material, unevenness in the fireproof coating material sprayed onto the surface to be treated can be eliminated, making the entire surface smooth. Effect of the Invention

[0012] According to the present invention, by spraying water onto a fire-resistant coating material and applying wind pressure from blowing air to the fire-resistant coating material through the surface of the fire-resistant coating material covered with the sprayed water, a fire-resistant finish can be applied to the fire-resistant coating material without the need for trowel pressing, thereby making it possible to reduce the labor required for fire-resistant coating work by spraying. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a diagram showing a spray nozzle and a spray application system used in the fire-resistant coating method of the present embodiment. [Diagram 2] FIG. 2 is a diagram showing a spray nozzle used in the fireproof coating method according to the present embodiment. [Diagram 3] FIG. 1 is a diagram showing a state in which spray construction is performed using the spray construction system according to the present embodiment. [Figure 4] FIG. 2 is a diagram showing a fireproof coating method in the present embodiment (when the spraying step and the fireproof finishing step are carried out simultaneously). [Diagram 5] FIG. 13 is a diagram showing experimental results regarding the fire-resistant covering method according to the present embodiment. [Figure 6] 1 is a photograph showing the state in which a fire-resistant coating material has been sprayed onto a surface to be treated in this embodiment. [Figure 7]FIG. 2 is a diagram showing a fireproof coating method in the present embodiment (wherein a fireproof finishing step is performed after a spraying step). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The fire-resistant coating method of the present invention can be adopted for both dry and semi-dry sprayed rock wool methods. In this embodiment, the semi-dry rock wool method is used as an example, and the details thereof will be described below with reference to Figs. 1 to 7.

[0015] Prior to describing the fire-resistant coating method, a spray nozzle 10 and a spray application system 50 used when spraying a fire-resistant coating material M as shown in FIG. 1 will be described.

[0016] <<Spray nozzle>> As shown in FIG. 1, the spray nozzle 10 includes a nozzle body 11 and a gun head 12 provided near the tip of the nozzle body 11.

[0017] 2, the gun head 12 is formed of a doughnut-shaped disk surrounding the nozzle body 11, and a plurality of slurry nozzles 13 are provided at equal intervals on the front surface near the inner periphery. Also, a plurality of mist nozzles 14 are provided at equal intervals near the outer periphery.

[0018] 1, one end of a slurry supply pipe 131 for supplying a cement slurry S is connected to the slurry nozzle 13. The other end of the slurry supply pipe 131 is connected via a slurry pump 21 to a slurry supply tank 22 for preparing a cement slurry S containing cement C and water W1.

[0019] Meanwhile, one end of a water supply pipe 141 that supplies water W2 in a state capable of being sprayed in a mist form is connected to the mist nozzle 14. The other end of the water supply pipe 141 is connected via a compressor 32 to a water tank 31 in which the water W2 is stored.

[0020] 1 and 2, the nozzle body 11 is formed in a generally cylindrical shape with both ends open, and a rock wool outlet 11a provided at the tip is disposed so as to communicate with a central opening from the rear side of the gun head 12. In addition, one end of a rock wool supply pipe 15 is connected to the rear end of the nozzle body 11.

[0021] The rock wool supply pipe 15 is composed of a flexible pipe with a diameter of about 50 mm, and the other end is connected to a rock wool supply mechanism 40 that supplies rock wool R. The rock wool supply mechanism 40 includes a hopper 42, a deflocculating device 41, and an air blower 43.

[0022] The hopper 42 is a container that discharges and supplies the input rock wool lumps RB to the defibrating device 41, which defibrates and crushes the supplied rock wool lumps RB. The rock wool R obtained by defibrating the rock wool lumps RB is supplied to the nozzle body 11 via the rock wool supply pipe 15 by blowing air using an air blower 43. The air blower 43 is a device that supplies low-pressure air with an effective discharge pressure of 200 kPa or less (according to "JIS B0132") among compressors.

[0023] 1 and 2, the rock wool R supplied to the nozzle body 11 in this manner is discharged from the rock wool outlet 11a and mixed with the cement slurry S sprayed from the slurry nozzle 13 to become the fireproof coating material M. Furthermore, the mist water W2 sprayed from the mist nozzle 14 adheres to the surface of the fireproof coating material M, so that at least a portion of the fireproof coating material M is covered with the mist water W2.

[0024] <<Spraying construction system>> As described above, the spray nozzle 10 capable of spraying the fireproof coating material M coated with mist-like water W2 is mounted on a spray construction system 50, which realizes labor-saving in spray construction, as shown in FIG. 1.

[0025] The spray construction system 50 includes a robot arm A and a traveling unit B equipped with the robot arm A. For details of the spray construction system 50, please refer to JP 2020-020206 A.

[0026] <Robot Arm> The robot arm A is equipped with a manipulator 51 having a multi-joint structure, the tip of which is provided with the above-mentioned spray nozzle 10 as an end effector, and a mounting jig 56 for mounting the spray nozzle 10.

[0027] In this embodiment, a six-axis articulated robot is used for the manipulator 51, which operates based on a job file and controls the operation of the spray nozzle 10. The job file describes information, including the movement path and posture of the spray nozzle 10 based on the operation of the manipulator 51 (such as the discharge direction of the fireproof coating material M discharged from the gun head 12), in the form of parameters and numerical values.

[0028] <Running Part> Traveling unit B includes at least a base unit 52 that supports the robot arm A, a traverse device 53, a traveling carriage 54, and a lifting device 55. The base unit 52 is installed so as to be freely movable along the longitudinal direction on the traverse device 53, and supports the robot arm A rotatably within its upper surface.

[0029] The traverse device 53 includes a long frame 531 and a traveling platform 532 that is movable along the longitudinal direction of the frame 531, and the above-mentioned base unit 52 is installed on this traveling platform 532. The traveling cart 54 has a structure that allows it to travel freely on the floor surface of the building 100, and the above-mentioned traverse device 53 is placed on it. The traveling cart 54 also includes an elevator 55 that can raise the traverse device 53.

[0030] For a traveling cart 54 configured in this manner, the traverse device 53 passes through the center of gravity of the traveling cart 54 in a planar view, and is positioned so that its longitudinal direction, i.e., the direction of movement of the base part 52 supporting the robot arm A, is parallel to the direction of travel of the traveling cart 54.

[0031] ≪≪Fireproof coating method≫≫ Taking as an example a case where a spray construction system 50 equipped with the above-mentioned spray nozzle 10 is used, the procedure for covering a construction target surface T with a fire-resistant covering material M by the fire-resistant covering method as shown in Fig. 3 will be described below. Note that in Fig. 3, the construction target surface T is set to a beam member 101 of a building 100.

[0032] In general, in fireproof coating work by spraying, after spraying the fireproof coating material M, a fireproof finish is performed by a worker pressing the surface with a trowel to suppress fuzzing that occurs on the surface of the fireproof coating material M and to remove unevenness and make the surface smooth. However, in the fireproof coating method, the fireproof finish of the fireproof coating material M is performed using mist water W2 and air blown by an air blower 43 without pressing the surface with a trowel.

[0033] <Fireproofing using mist water and air blower> Specifically, as shown in FIG. 7(b), air is blown by an air blower 43 toward the fire-resistant coating material M that is being sprayed onto the treatment target surface T and is being covered with the mist-like water W2.

[0034] As a result, the fire-resistant coating material M is covered with the mist of water W2 and receives wind pressure, which presses the surface of the material against the wind and suppresses fluffing. In addition, the wind pressure exerts a pressing force similar to that of a trowel, acting in various directions including the direction of the spray thickness of the fire-resistant coating material M. Therefore, by blowing air at a predetermined volume while moving along the surface of the fire-resistant coating material M, it is possible to eliminate unevenness in the fire-resistant coating material M sprayed onto the application target surface T and to smooth the entire surface.

[0035] This effect can be obtained not only by blowing air onto the fire-resistant coating material M after it has been sprayed onto the surface T to be treated and applying wind pressure, but also by adjusting the volume of air blown by the air blower 43 and performing the spraying work of the fire-resistant coating material M at the same time.

[0036] Therefore, two procedures for the fire-resistant coating method are described below: one in which the fire-resistant finish is performed at the same time as the spraying of the fire-resistant coating material M, and one in which the fire-resistant finish is performed after spraying the fire-resistant coating material M onto the surface T to be treated.

[0037] <<When carrying out fireproofing at the same time as spraying work>> When spraying the fire-resistant coating material M and performing the fire-resistant finish at the same time, the following preparatory work is carried out in advance.

[0038] <Advance preparation> <Cement slurry mixing> The cement slurry S to be supplied to the slurry nozzle 13 is prepared and mixed in a slurry supply tank 22 as shown in Fig. 1. The cement slurry S is prepared by mixing water W1 and cement C so as to satisfy the standard mix ratio stipulated in the "Sprayed Rockwool Covered Fireproof Structure Construction Management Guidelines Revised in 2012 Rockwool Industry Association" (hereinafter referred to as the "Construction Management Guidelines").

[0039] <Adjusting the water mist> The pressure of the compressed air and the amount of discharged air required to spray the mist water W2 from the mist nozzle 14 are adjusted by a compressor 32. In addition, the amount of water W2 to be sprayed is adjusted so that it does not affect the mix of the cement slurry S when it adheres to the fireproof coating material M.

[0040] <Air blower air volume (output) adjustment> The output of the air blower 43 is set so as to secure an air volume that satisfies two functions, the discharge / spray function and the pressing function. The discharge / spray function is a function of discharging rock wool R from the rock wool outlet 11a of the nozzle body 11 and spraying the fireproof coating material M, which is a mixture of the discharged rock wool R and the cement slurry S, onto the construction target surface T.

[0041] As described above, the pressing function is a function of pressing the fireproof coating material M that has been sprayed onto the application target surface T and is covered with the mist-like water W2. Therefore, the air volume of the air blower 43 is increased compared to the air volume set in consideration of only the spraying function that has been conventionally adopted. The air volume is set to a level that does not cause the fireproof coating material M discharged from the spray nozzle 10 to bounce back without adhering to the application target surface T.

[0042] <Adjusting the discharge rate of rock wool and cement slurry> The amount of cement slurry S discharged is adjusted according to the air volume of the air blower 43 described above so that the amount of cement slurry S discharged relative to the amount of rock wool R discharged is the mixture ratio specified in the construction management guidelines described above.

[0043] <Spraying process, spraying process and fireproofing process> First, rock wool R is discharged from the rock wool discharge port 11a, and cement slurry S is discharged from the slurry nozzle 13.

[0044] With the air volume of the air blower 43 set to a volume that ensures the two functions of spraying and pressing, the rock wool R is discharged and the cement slurry S is discharged from the slurry nozzle 13 until the fireproof coating material M having a mixture ratio that satisfies the above-mentioned construction management guidelines is stably obtained. When the discharge of the fireproof coating material M has stabilized, water W is sprayed from the mist nozzle 14, and it is confirmed that the mist-like water W2 adheres to the surface of the fireproof coating material M.

[0045] Thereafter, as shown in Fig. 3, the spray application system 50 is operated to move the spray nozzle 10 along a moving path, moving speed, and posture based on the job file, while spraying the fire-resistant coating material M onto the application target surface T. Then, as shown in Fig. 4, the mist of water W2 not only moistens the scattering dust including rock wool R, which is a conventional use, to prevent scattering to the outside, but also coats the surface of the fire-resistant coating material M.

[0046] This largely eliminates the fuzzing that occurs on the surface of the fire-resistant coating material M sprayed onto the application target surface T. In addition, the fire-resistant coating material M is pressed in various directions including the spray thickness direction by the wind pressure from the air blower 43 that is discharged together with the rock wool R from the rock wool outlet 11a. At this time, the air blower 43 blows air at a constant speed (spraying speed) along the fire-resistant coating material M while maintaining a constant air volume that takes into account the discharge / spraying function and the pressing function.

[0047] Then, the wind pressure acts uniformly on the entire fire-resistant coating material M sprayed onto the work target surface T, and presses the entire fire-resistant coating material M in various directions including the spray thickness direction through the surface covered with the mist water W2. As a result, the unevenness that occurred on the surface of the fire-resistant coating material M is leveled, and a smooth finished surface can be obtained, as if a worker had pressed it with a trowel.

[0048] In this way, by using the mist water W2 and the air blown by the air blower 43 with the air volume adjusted in consideration of the two functions of the discharge spraying function and the pressing function, it becomes possible to perform fireproofing simultaneously with the spraying work. The results of an experiment in which the air volume of the air blown by the air blower 43 was changed to perform fireproofing simultaneously with the spraying work are shown in Figures 5 and 6 below.

[0049] <<Experimental Results>> In the experiment, the air volume was changed by changing the output of the air blower 43 in four stages, and for each air volume, the fireproof coating method was carried out in which the fireproof finish was simultaneously performed while the spraying work was performed according to the above procedure. The surface condition of the fireproof coating material M after the work was evaluated by visual inspection.

[0050] The output of the air blower 43 was set to four levels, 30, 45, 52.5, and 60 Hz, as shown in Fig. 5. The air volume was calculated by multiplying the air speed by the area of ​​the rock wool nozzle 11a, and the air speed for each output was measured by an anemometer placed at a position about 500 mm away from the spray nozzle 10.

[0051] The diameter of the rock wool nozzle 11a was 50 mm, and the cement slurry S was mixed to have a slurry concentration of 33.3% (cement:water=1:2). The compressor 32 used to supply the water W that can be sprayed in a mist was set to a control pressure of 0.8 to 1.0 MPa and a discharge air amount of about 300 L / min.

[0052] In addition, the mixing ratio of rock wool R and cement slurry S complies with the standard mixing ratio stipulated in the above-mentioned construction management guidelines, and is set to rock wool:cement = 60%:40% (with a tolerance of ±5% for each), and a fiberizer with a maximum discharge capacity of 12 kg / min is used as the fiber-defibrating device 41.

[0053] FIG. 6(a) shows the state of the fireproof coating material M when the output of the air blower 43 is set to 30 Hz and the fireproof finish is performed simultaneously with the spraying of the fireproof coating material M under the above conditions. As shown in FIG. 5, the air volume when the output of the air blower 43 is set to 30 Hz is 70 m 3 / hour, which is about the same output as that used in the conventional semi-dry sprayed rock wool method, in other words, it is equivalent to the air volume taking into account only the spray function.

[0054] As can be seen from Figure 6(a), the fire-resistant coating material M sprayed onto the target surface T has unevenness and projections all over its surface, and there is also a lot of fuzziness, indicating that a fire-resistant finish is required.

[0055] Next, the output of the air blower 43 is increased to 60 Hz, and the state of the fireproof coating material M when the fireproof finish is performed simultaneously with the spraying of the fireproof coating material M under the above conditions is shown in FIG. 6(b). When the output of the air blower 43 is set to 60 Hz, the air volume is 155 m 3 / hour, which is more than twice the airflow when set to 30Hz.

[0056] As shown in FIG. 6(b), the fireproof coating material M sprayed onto the target surface T has a smooth surface, with no unevenness or fuzziness on the entire surface. In this way, the amount of air blown by the air blower 43 should be adjusted taking into account not only the blowing function but also the pressing function (at least 150 m 3 / hour), in combination with the mist of water W2, it is possible to obtain a fire-resistant finish to the extent that the need for trowel pressure is eliminated.

[0057] The above fireproof coating method can also be carried out manually by workers. However, by adopting the spray application system 50, even when the air blower 43 has a high output and a large air volume, the distance between the spray nozzle 10 and the application target surface T can be stably and constantly maintained. In addition, the moving speed of the spray nozzle 10 can also be kept constant. This not only reduces the number of personnel required, but also makes it possible to finish the surface of the fireproof coating material M with higher accuracy.

[0058] <<When applying fireproofing after spraying work>> The procedure for applying the fireproof finish after spraying the fireproof coating material M is as follows:

[0059] <Spraying process> As a preliminary preparation for the spraying process, the cement slurry S is mixed and the discharge rates of the rock wool R and cement slurry S are adjusted in the same manner as when fireproofing is performed simultaneously with the spraying work.

[0060] Thereafter, in the same procedure as in the conventional semi-dry sprayed rock wool method, as shown in Fig. 7(a), the spray construction system 50 is operated, and the fireproof coating material M is sprayed onto the construction target surface T while moving the spray nozzle 10 along a moving path, moving speed, and posture based on the job file. Therefore, the air blower 43 only needs to have an air volume that takes into account the discharge and spraying function, and does not spray mist water W2.

[0061] <Spraying process and fireproofing process> As a preliminary preparation for the fireproofing process, in the same way as when fireproofing is performed simultaneously with the spraying work, the pressure of the compressed air and the amount of discharged air required to spray the water W in a mist form from the mist nozzle 14 are adjusted. Also, the output of the air blower 43 is adjusted so that the air volume takes into consideration the above-mentioned pressing function.

[0062] After the above preparations are completed, as shown in Fig. 7(b), the spray construction system 50 is operated to apply mist water W2 sprayed from the mist nozzle 14 to the surface of the fire-resistant coating material M sprayed onto the treatment target surface T, and air is blown by the air blower 43 through the rock wool outlet 11a toward the surface of the fire-resistant coating material M. At this time, the spray construction system 50 may move the spray nozzle 10 according to the movement path, movement speed, and posture using a job file for the spraying work.

[0063] As a result, without carrying out trowel pressing work in the fireproof finishing process, it is possible to eliminate fuzziness and unevenness that occurs on the surface of the fireproof coating material M sprayed onto the treatment target surface T by utilizing the spray nozzle 10 and spray application system 50 used in the spraying process. Therefore, even when the spraying process and the fireproof finishing process are carried out in separate processes, it is possible to carry out the fireproof coating repair method while reducing the number of workers required.

[0064] The spraying process does not necessarily have to utilize the spray nozzle 10 and the spraying construction system 50, and may be performed manually by a worker.

[0065] In addition, the spraying process of spraying the mist water W2 and the fireproof finishing process of applying air pressure by blowing air from the air blower 43 are performed in parallel, but the present invention is not limited to this. In other words, the mist water W2 may be sprayed first, and then the air blowing operation by the air blower 43 may be performed.

[0066] Furthermore, the spraying step of spraying the mist water W2 may be performed in the blowing step. In this way, not only can the surface of the fireproof coating material M be covered with the mist water W2 in the blowing step, but also the scattering dust containing the rock wool R can be moistened to prevent scattering to the outside.

[0067] The fire-resistant coating method of the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present invention.

[0068] For example, in this embodiment, the spray nozzle 10 shown in Figures 1 and 2 is used, but the structure and shape are not necessarily limited to this. Similarly, the spray construction system 50 is not limited to this, and any device that contributes to the automation of spray construction may be used. [Explanation of symbols]

[0069] 10 Spray nozzle 11 Nozzle body 11a Rock wool nozzle 12 Gunhead 13 Slurry nozzle 131 Slurry supply pipe 14 Mist nozzle 141 Water supply pipe 15 Rock wool supply pipe 21 Slurry pump 22 Slurry supply tank 31 Water Tank 32 Compressor 40 Rock wool supply mechanism 41 Cotton opening device 42 Hopper 43 Air Blower 50 Spraying construction system 51 Manipulator 52 Base 53 Traversing device 531 frames 532 Traveling platform 54 Traveling cart 541 Rectangular tabletop 542 Cart body 543 Means of transportation 55 Lifting device 56 Mounting jig A Robot Arm B Running part M Fireproof coating RB Rock wool block R Rockwool S Cement Slurry T Construction target surface W1 water W2 Water (misted water)

Claims

[Claim 1] A spraying process of spraying a fireproof coating material onto a surface to be treated; A spraying step of spraying water onto the fireproof coating material; a fireproof finishing process in which the fireproof coating material covered with the sprayed water is pressed by wind pressure from blowing air to suppress fuzzing occurring on the surface of the fireproof coating material and to remove unevenness to make the surface smooth; A fire-resistant coating method comprising:

Images