Spray nozzle and spray application system

Abstract

To reduce the number of people required for fireproof coating work by spraying.SOLUTION: There is provided a spray nozzle for spraying a fire-resistant coating material onto a surface to be applied includes a nozzle body having a rock wool nozzle for ejecting or blowing rock wool, and a gun head formed into a doughnut-shaped disk surrounding the nozzle body. The gun head includes a plurality of slurry nozzles for spraying cement slurry which is mixed with the rock wool to form the fire-resistant coating material, and a plurality of mist nozzles for spraying water. The slurry nozzles are positioned near the inner periphery of the gun head.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a spray nozzle and a spray application system used for carrying out fireproof coating work by spray application. [Background technology]

[0002] Steel-framed buildings are made fireproof by carrying out fireproof coating work, which involves covering the surface of the structure with a fireproof coating material. Known methods for carrying out fireproof coating work by spraying include the dry method and the semi-dry method. The dry method involves spraying a mixture of premixed rock wool cement onto the surface to be treated, while the semi-dry method involves spraying a mixture of rock wool and cement slurry onto the surface to be treated. For example, Patent Document 1 discloses a nozzle for spraying rock wool for use in the semi-dry method.

[0003] Specifically, the cement slurry and rock wool are pumped separately and sprayed simultaneously from a nozzle to mix them and spray them onto the object, and multiple cement slurry spray tips are placed 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 a spraying construction is carried out using a nozzle such as that disclosed in Patent Document 1, a sprayed layer can be formed efficiently, but there is a problem in that rock wool that does not adhere to the cement is likely to scatter. For this reason, Patent Document 2 provides a spraying nozzle with a spraying part that can spray 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 Documents 1 and 2, the surface of the sprayed layer may be uneven or frayed, and the sprayed layer may not adhere sufficiently to the object to be treated. For this reason, it is mandatory to apply a fire-resistant finish to the sprayed layer formed on the surface to be treated by trowel pressing, 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] Japanese Patent Application Publication No. 2020-040020 [Patent Document 3] Japanese Patent Application Publication No. 2018-096103 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the trowel holding work requires manpower, and 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. In particular, in recent years, many work sites have introduced spraying robots with the aim of reducing the labor required for spraying work and improving work efficiency, and in such cases, it may be necessary to secure manpower for the trowel holding work and prepare equipment such as work scaffolding or aerial work vehicles.

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

[0009] To achieve this object, the spray nozzle of the present invention is a spray nozzle for spraying a fire-resistant coating material onto a surface to be applied, and includes a nozzle body having a rock wool outlet for discharging or blowing air into the rock wool, and a gun head formed in a doughnut-shaped disk surrounding the nozzle body, the gun head comprising a plurality of slurry nozzles for spraying cement slurry that is mixed with the rock wool to form the fire-resistant coating material, and a plurality of mist nozzles for spraying water, the slurry nozzles being arranged near the inner periphery of the gun head.Furthermore, the spray application system of the present invention is a spray application system equipped with the spray nozzle of the present invention, and comprising a robot arm having a spray nozzle attached to its tip, and a traveling unit on which the robot arm is mounted.

[0010] According to the spray nozzle and spray application system of the present invention, water is sprayed onto a fire-resistant coating material, and wind pressure from blown air is applied to the fire-resistant coating material through the surface of the fire-resistant coating material that is covered with the sprayed water. As a result, the fire-resistant coating material is pressed against the surface by being covered with the mist-like water and being subjected to the wind pressure, thereby suppressing pilling.

[0011] In addition, the wind pressure exerts a pressure on the fire-resistant coating material similar to that of a trowel. Therefore, by blowing air at a predetermined volume while moving along the surface of the fire-resistant coating material, unevenness in the fire-resistant coating material sprayed onto the surface to be treated can be eliminated, making the entire surface smooth. [Effects 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 coated with the sprayed water, a fire-resistant finish can be applied to the fire-resistant coating material without using a trowel to hold it down, making it possible to reduce the labor required for fire-resistant coating work by spraying. [Brief explanation of the drawings]

[0013] [Figure 1]1 is a diagram showing a spray nozzle and a spray application system used in a fire-resistant coating method according to the present embodiment. FIG. [Figure 2] FIG. 2 is a diagram showing a spray nozzle used in the fire-resistant coating method according to the present embodiment. [Figure 3] 1 is a diagram showing how spray construction is performed using the spray construction system of this embodiment. FIG. [Figure 4] 1 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). FIG. [Figure 5] 10A and 10B are diagrams 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. 1 is a diagram showing a fireproof coating method according to the present embodiment (in the case where a fireproof finishing step is performed after a spraying step). DETAILED DESCRIPTION OF THE INVENTION

[0014] The spray nozzle and spray construction system of the present invention can be used for both dry and semi-dry spray rock wool construction methods, but in this embodiment, the case of using semi-dry rock wool construction method is taken as an example, and the details will be explained below with reference to Figures 1 to 7.

[0015] Before 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 has a plurality of slurry nozzles 13 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 that supplies 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 that prepares 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 that can be sprayed into a mist 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 arranged so as to communicate with the central opening from the back 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 made 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 air blowing 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"), even 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 form the fire-resistant coating material M. Furthermore, the mist water W2 sprayed from the mist nozzle 14 adheres to the surface of the fire-resistant coating material M, so that at least a portion of the fire-resistant 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 fire-resistant coating material M coated with mist-like water W2 is mounted on a spray construction system 50, which reduces the labor required for spray construction, as shown in Figure 1.

[0025] The spraying construction system 50 includes a robot arm A and a traveling unit B equipped with the robot arm A. For details of the spraying construction system 50, please refer to Japanese Patent Application Laid-Open No. 2020-020206.

[0026] <Robot Arm> The robot arm A is provided with a manipulator 51 having an articulated structure, the spray nozzle 10 being provided at the tip thereof 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 contains information, in the form of parameters and numerical values, 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 fire-resistant coating material M discharged from the gun head 12).

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

[0029] The traverse device 53 comprises a long frame 531 and a traveling platform 532 that is movable along the longitudinal direction of the frame 531, and the aforementioned base unit 52 is installed on this traveling platform 532. The traveling carriage 54 has a structure that allows it to travel freely on the floor surface of the building 100, and carries the aforementioned traverse device 53. The traveling carriage 54 also has a built-in lifting device 55 that can raise the traverse device 53.

[0030] For a traveling carriage 54 configured in this manner, the traverse device 53 passes through the center of gravity of the traveling carriage 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 carriage 54.

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

[0032] In general, in fire-resistant coating work using spraying, after spraying the fire-resistant coating material M, a worker presses it down with a trowel to prevent fuzzing that occurs on the surface of the fire-resistant coating material M and to smooth out any unevenness as a fire-resistant finish. However, in the fire-resistant coating method, the fire-resistant finish of the fire-resistant coating material M is performed using mist water W2 and air blown by an air blower 43 without pressing it down with a trowel.

[0033] <Fireproof finish 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 has been sprayed onto the application target surface T and is in a state of being covered with the atomized water W2.

[0034] As a result, the fire-resistant coating material M is covered with the mist of water W2 and subjected to wind pressure, which presses its surface and prevents it from fuzzing. The wind pressure also exerts a pressing force similar to that of a trowel, acting in various directions, including the direction of the sprayed 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 any unevenness in the fire-resistant coating material M sprayed onto the target surface T and smooth the entire surface.

[0035] This effect can be achieved 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 air volume blown by the air blower 43 when spraying 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 the fire-resistant coating material M is sprayed onto the surface T to be treated.

[0037] <<<When applying fireproofing at the same time as spraying>>> In order to perform the fireproofing finish simultaneously with the spraying of the fireproof coating material M, the following preparatory work is carried out in advance.

[0038] <<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 Figure 1. The cement slurry S is prepared by mixing water W1 and cement C so as to satisfy the standard mix specified in the "Sprayed Rockwool Coated Fireproof Structure Construction Management Guidelines Revised in 2012, Rockwool Industry Association" (hereinafter referred to as the "Construction Management Guidelines").

[0039] <Adjusting the mist of water> 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. The amount of water W2 to be sprayed is also adjusted so that it does not affect the blending 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 to ensure an air volume that satisfies the two functions of 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 cement slurry S, onto the surface T to be worked on.

[0041] As described above, the pressing function is a function of pressing the fire-resistant 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 prevents the fire-resistant coating material M discharged from the spray nozzle 10 from bouncing back without adhering to the application target surface T.

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

[0043] <Spraying process, atomization 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 sufficient to perform both the spraying and pressing functions, rock wool R is discharged and cement slurry S is discharged from the slurry nozzle 13 until a fire-resistant coating material M having a mixture ratio that satisfies the above-mentioned construction management guidelines is obtained. Once the discharge of the fire-resistant coating material M has stabilized, water W is sprayed from the mist nozzle 14, and it is confirmed that mist-like water W2 adheres to the surface of the fire-resistant coating material M.

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

[0046] This significantly reduces the fuzzing that occurs on the surface of the fire-resistant coating material M sprayed onto the application target surface T. In addition, the air pressure from the air blower 43, which discharges the air together with the rock wool R from the rock wool outlet 11a, presses the fire-resistant coating material M in various directions, including the direction of the spray thickness. 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] The wind pressure then acts uniformly on the entire fire-resistant coating material M sprayed onto the target surface T, pressing the entire fire-resistant coating material M in various directions, including the spray thickness direction, through the surface covered with the mist of water W2. This smooths out any unevenness that has occurred on the surface of the fire-resistant coating material M, resulting in a smooth finished surface, just as if a worker had pressed it down with a trowel.

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

[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 performed simultaneously with the spraying work according to the above procedure. The surface condition of the fireproof coating material M after the experiment 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 Figure 5. The air volume was calculated by multiplying the air speed by the area of ​​the rock wool outlet 11a, and the air speed for each output was measured with 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 prepared to have a slurry concentration of 33.3% (cement:water = 1:2). The compressor 32 used to supply water W that can be sprayed in mist form was set to a control pressure of 0.8 to 1.0 MPa and a discharge air volume of approximately 300 L / min.

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

[0053] FIG. 6(a) shows the state of the fire-resistant covering material M when the output of the air blower 43 is set to 30 Hz and the fire-resistant finish is simultaneously performed on the fire-resistant covering material M under the above conditions. As can be seen from FIG. 5, when the output of the air blower 43 is set to 30 Hz, the air volume is 70 m 3 / hour, which is about the same as the output used in the conventional semi-dry sprayed rock wool method, that is, it is equivalent to the air volume taking into account only the spraying 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 protrusions 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 was increased to 60 Hz, and the state of the fire-resistant coating material M was shown in Figure 6(b) when the fire-resistant finishing was carried out simultaneously with the spraying of the fire-resistant coating material M under the above conditions. As can be seen from Figure 5, the air volume when the output of the air blower 43 was set to 60 Hz was 155 m 3 / hour, which is more than double the airflow when set to 30Hz.

[0056] As can be seen from Figure 6(b), the fire-resistant coating material M sprayed onto the surface T to be treated has a smooth surface, with no unevenness or fluffing on the entire surface. In this way, the air blower 43 should be adjusted to a volume of at least 150 m / s, taking into consideration not only the discharge / blow function but also the pressing function. 3 / hour), combined with the mist of water W2, it is possible to obtain a fire-resistant finish to the extent that the need for trowel pressure can be omitted.

[0057] The above-described fire-resistant coating method can also be performed manually by workers. However, by using the spray application system 50, the distance between the spray nozzle 10 and the target surface T can be stably maintained constant even when the air blower 43 has a high output and a large air volume. The moving speed of the spray nozzle 10 can also be maintained constant. This not only reduces the number of workers required, but also enables the surface of the fire-resistant coating material M to be finished with higher precision.

[0058] <<When applying a fireproof finish 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 way as when the fireproofing finish is performed simultaneously with the spraying work.

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

[0061] <Spraying process and fireproofing finishing process> As a preliminary preparation for the fireproofing process, similar to 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 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 Figure 7(b), the spraying 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 spraying construction system 50 simply moves the spray nozzle 10 according to the travel path, travel speed, and posture using a job file for the spraying work.

[0063] As a result, without performing 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 performed 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 use the spray nozzle 10 and the spraying system 50, and may also be performed manually by workers.

[0065] In addition, the spraying process of spraying the mist water W2 and the fireproof finishing process of applying wind pressure by blowing air from the air blower 43 were carried out in parallel, but this is not limitative. In other words, the mist water W2 may be sprayed first, and then the air blowing operation by the air blower 43 may be carried out.

[0066] Furthermore, the spraying step of spraying the mist water W2 may be performed in the spraying step. In this way, the mist water W2 not only coats the surface of the fire-resistant coating material M in the spraying step, but also moistens the scattered dust containing rock wool R, thereby preventing it from scattering to the outside.

[0067] The spray nozzle and spray application system of the present invention are not limited to the above-described embodiment, and various modifications are possible within the 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 Traverse device 531 frames 532 Traveling stand 54 Traveling cart 541 Rectangular top 542 Bogie body 543 Transportation 55 Lifting device 56 Mounting jig A. Robot arm B Running part M Fireproof coating RB Rockwool Block R Rockwool S Cement slurry T Construction target surface W1 water W2 Water (misted water)

Claims

1. A spray nozzle for spraying a fire-resistant coating material onto a surface to be applied, A nozzle body having a rock wool outlet for discharging or blowing rock wool; a gun head formed in a doughnut-shaped disk surrounding the nozzle body; The gun head is The apparatus includes a plurality of slurry nozzles for spraying cement slurry that is mixed with the rock wool to form the fire-resistant coating material, and a plurality of mist nozzles for spraying water, The spray nozzle is characterized in that the slurry nozzle is disposed near the inner periphery of the gun head.

2. A spraying system equipped with the spray nozzle of claim 1, A robot arm with a spray nozzle attached to the tip, A spraying construction system characterized by comprising: a traveling unit on which the robot arm is mounted.

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