JP2022172022A - Removal method and removal device of asbestos-containing layer - Google Patents

Abstract

To remove an asbestos-containing layer formed on a surface of a structure without providing a shield space, without necessity for a worker to wear a protective clothing, in a shorter time than the time required in a conventional one.SOLUTION: A removal device D of an asbestos-containing layer L includes laser irradiation means 1 and gas injection means 2. The laser irradiation means 1 irradiates the asbestos-containing layer L with laser light to melt the asbestos-containing layer L. The gas injection means 2 includes a first nozzle 22 that injects a gas to an irradiation spot SP of laser light and removes a molten material from a surface of a structure S, and a second nozzle 23 that eliminates a flying object including a molten material jetted onto an optical path of the laser light from the optical path. The irradiation spot SP of the laser light is movable relative to the structure S.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method and apparatus for removing an asbestos-containing layer.

Asbestos (asbestos) is a fibrous silicate mineral that occurs naturally. In the past, asbestos was sprayed for the purpose of heat insulation and heat insulation in construction work such as buildings, but scattered and floating asbestos fibers It is said to cause pulmonary fibrosis (pneumoconiosis) and malignant mesothelioma when inhaled by humans. Since then, it has been used for slate materials, brake linings, brake pads, soundproofing materials, heat insulating materials, heat retaining materials, etc., but currently its production is prohibited in principle.

In addition, when demolishing, refurbishing, or repairing a building that uses building materials containing asbestos, it is obligatory to notify the prefectural government in advance and take measures to prevent the scattering of asbestos.

As a method to remove asbestos sprayed on the ceilings, walls, beams, floors, etc. of structures such as buildings, the work site is surrounded by sheets to create a shielded space, and the inside is made into a negative pressure and the asbestos is removed by work tools such as keren sticks. A method of scraping off the sprayed layer (e.g. Patent Document 1), a method of blowing off the asbestos-sprayed layer by spraying high-pressure water jets and peeling it off (e.g. Patent Document 2), and irradiating the asbestos-sprayed layer with a laser beam to thermally decompose and melt the asbestos. Alternatively, a method of evaporating to render it harmless (for example, Patent Document 3) has been proposed.

JP-A-3-51480 JP-A-11-200639 JP 2009-28717 A

According to the method described in Patent Document 3, in which asbestos is irradiated with a laser beam to melt it and render it harmless, it is believed that the work environment will be improved in that it will not be necessary to take measures against scattering of asbestos or wear protective clothing for workers. be done.

However, in order to completely melt and detoxify asbestos by laser light irradiation, it is necessary to irradiate the asbestos for a predetermined time or more per unit area.

The present invention has been made in view of such conventional problems, and its object is to provide a method and apparatus capable of removing an asbestos-containing layer formed on the surface of a structure in a shorter period of time than before. to do.

Another object of the present invention is to provide a method and apparatus capable of removing an asbestos-containing layer formed on the surface of a structure without providing a shielded space and without the worker wearing protective clothing. to do.

A method for removing an asbestos-containing layer according to the present invention for achieving the above object is a method for removing an asbestos-containing layer formed on the surface of a structure, comprising: The method is characterized in that the asbestos-containing layer is melted while the portion irradiated with light is relatively moved, and the melt is removed from the surface of the structure by injecting gas to the portion irradiated with laser light.

In the method for removing an asbestos-containing layer having the above configuration, it is preferable to inject gas from the downstream side in the moving direction of the portion irradiated with the laser beam.

Further, in the method for removing an asbestos-containing layer having the above configuration, it is preferable that a gas is also injected to the optical path of the laser beam to remove flying objects including the melted matter from the optical path.

Further, in the method for removing an asbestos-containing layer having the above configuration, it is preferable that the flying object including the melt is sucked together with the gas.

Further, in the method for removing an asbestos-containing layer having the above configuration, it is preferable that flying objects including melted matter are sucked together with gas from the upstream side in the moving direction of the portion irradiated with the laser beam.

Moreover, in the method for removing an asbestos-containing layer having the above configuration, it is preferable to separate and recover the melted material from the sucked material.

An apparatus for removing an asbestos-containing layer according to the present invention for achieving the above object is an apparatus for removing an asbestos-containing layer formed on a surface of a structure, comprising laser irradiation means and gas injection means, The laser irradiation means irradiates the asbestos-containing layer with a laser beam to melt the asbestos-containing layer, and the gas injection means injects gas onto the laser beam irradiated portion to remove the melted matter from the surface of the structure. and a portion irradiated with the laser beam is movable relative to the structure.

In the apparatus for removing an asbestos-containing layer having the configuration described above, it is preferable that the first nozzle injects gas from the downstream side in the movement direction of the portion irradiated with the laser beam to the portion irradiated with the laser beam.

In the apparatus for removing an asbestos-containing layer having the above configuration, the gas injection means preferably includes a second nozzle for injecting gas into the optical path of the laser beam to remove flying objects including the melted matter from the optical path.

Moreover, it is preferable that the asbestos-containing layer removing apparatus having the above configuration further includes a suction means, and the suction means sucks the flying matter including the molten matter together with the gas.

Further, in the apparatus for removing an asbestos-containing layer configured as described above, the suction means includes a suction head having a suction opening and a discharge opening, and the suction head is configured such that the suction opening is on the upstream side in the moving direction of the portion irradiated with the laser beam. It is preferable that it is arranged so as to face the portion irradiated with the laser light.

Further, in the apparatus for removing an asbestos-containing layer configured as described above, the suction means includes a suction head having a suction opening and a discharge opening, the suction opening is provided so as to face the structure, and the suction head includes at least It is preferable to arrange so as to cover the irradiation portion of the laser light and its surroundings.

Moreover, it is preferable that the apparatus for removing an asbestos-containing layer configured as described above further includes separating and recovering means, wherein the separating and recovering means separates and recovers the molten material from the sucked material sucked by the sucking means.

According to the present invention, an asbestos-containing layer formed on the surface of a structure can be removed in a shorter time than conventionally. In addition, the asbestos-containing layer formed on the surface of the structure can be removed without the worker wearing protective clothing.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows an example of the removal apparatus of 1st Embodiment, and a removal method. BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view of the principal part which shows an example of the removal apparatus of 1st Embodiment, and a removal method. FIG. 10 is a schematic diagram of a main part showing an example of a removing device and a removing method of a second embodiment; 4 is a photograph of a trace of removal of an asbestos-containing layer in an example. It is a photograph of the trace of removal of the asbestos-containing layer and its bottom surface at a moving speed of 7 m/min.

The apparatus and method for removing an asbestos-containing layer according to the present invention (hereinafter sometimes simply referred to as "removing apparatus" and "removing method") will now be described in more detail with reference to the drawings. It is not limited to any embodiment.

(First embodiment)
FIG. 1 is a schematic diagram showing an example of an apparatus for removing an asbestos-containing layer according to the present invention, and FIG. 2 is a perspective view of the main part of the removing apparatus. The removal device D includes laser irradiation means 1 , gas injection means 2 and suction means 3 . The removal device D is movable relative to the structure S, and the removal device D moves when removing the asbestos-containing layer L on the outer wall or inner wall of a building such as a building. Considering practical workability, the relative movement speed of the removal device D is desirably 5 m/min or more, more preferably 7 m/min or more when the removal width is about 5 mm. The means for moving the removing device D may be, for example, a manipulator having a multi-joint arm, or may be moved by an operator's operation.

(Laser irradiation means 1)
The laser irradiation means 1 has a laser transmitter 11 , a fiber cable 12 for transmitting laser light, and a processing head 13 . A laser beam emitted from a laser transmitter 11 is transmitted through a fiber cable 12 and guided to a processing head 13 . The laser beam reaching the processing head 13 is condensed by a lens 14 incorporated in the processing head 13 to form an irradiation spot (irradiation portion) SP having a predetermined shape.

As the laser transmitter 11 used in the laser irradiation means 1, conventionally known laser transmitters such as solid laser transmitters and gas laser transmitters can be used. From the viewpoint of (1), solid laser transmitters such as semiconductor laser transmitters and fiber laser transmitters are preferably used. The actual output of the laser transmitter 11 is about several kW to several tens of kW.

The fiber cable 12 has the function of guiding the laser beam emitted from the laser transmitter 11 to the processing head 13, and may be provided in a single piece or a plurality of pieces. Alternatively, a laser beam branching optical device may be provided between the processing head 13 and laser beams may be transmitted to a plurality of processing heads.

The processing head 13 constricts the laser beam emitted from the laser transmitter 11 to form an irradiation spot SP having a predetermined shape, and irradiates the asbestos-containing layer L on the surface of the structure S with the irradiation spot SP. The shape of the irradiation spot SP may be, for example, any shape such as a square shape or a circular shape, but a square shape is preferable from the viewpoint of work efficiency and the like.

There is no particular limitation on the area of the irradiation spot SP, and the area should be such that the asbestos-containing layer L can be melted in consideration of the output of the laser transmitter 11 and the like. The area of the irradiation spot SP can be adjusted by adjusting the distance from the focal position of the laser beam.

In order to reliably remove the asbestos-containing layer L, it is important that the laser energy reaches the interface between the asbestos-containing layer L and the structure S. On the other hand, it is also important that the structure S is not affected by the laser beam irradiation. The energy imparted by the irradiation of the laser light can be controlled by the power of the laser light, the focal length of the lens 14, the irradiation angle, the moving speed, and the like.

The irradiation angle of the laser beam from the processing head 13 to the structure S may be perpendicular to the asbestos _- containing layer L, or may have _a predetermined forward angle θ1 or backward angle θ2. In order for the flying object including the molten material to be quickly removed from the optical path of the laser beam by the gas injection means 2 to be described later and the laser beam to efficiently reach the asbestos-containing layer L without being absorbed by the flying object, the processing head 13 It is preferable that the irradiation angle of the laser light from the has _an advancing angle θ1. From the viewpoint of melting and removing the asbestos-containing layer L more efficiently, the advancing angle θ1 is preferably in the range of ₁₀ ° or more and 30° or less.

In order to melt the asbestos-containing layer L while minimizing the impact on the structure S, control of the laser energy density and laser beam scanning speed is important. Also, the amount of gas injected from the gas injection means 2 and the shape and arrangement of the suction means 3 are important. The laser energy density is preferably in the range of 2 kW/cm ² to 14 kW/cm ² . The moving speed of the laser irradiation spot SP is appropriately determined in consideration of the size of the irradiation spot SP so that the removal area of the asbestos-containing layer per unit time is 5 m ² /h to 10 m ² /h, which is suitable for practical use. can be determined, and generally the range of 1 m/min to 15 m/min is preferred.

(Gas injection means 2)
The gas injection means 2 includes a compressor 21 that compresses gas to generate a gas (assist gas) having a predetermined pressure, a first nozzle 22 that sprays the generated assist gas onto the irradiation spot SP, and a and a second nozzle 23 for removing flying objects including the spouted melt from the optical path. The first nozzle 22 is located downstream of the irradiation spot SP in the direction of movement of the irradiation spot, and blows an assist gas toward the irradiation spot SP. The closer the first nozzle 22 is to the irradiation spot SP, the more effectively the molten material can be removed from the structure S. Therefore, it is preferable to install the first nozzle 22 in the vicinity of the irradiation spot SP as long as it does not interfere with the laser beam. The blowing angle of the assist gas from the first nozzle 22 may be appropriately determined so that the melted material of the asbestos-containing layer L and the like are removed from the structure S efficiently.

The second nozzle 23 is located downstream of the irradiation spot SP in the direction of movement of the irradiation spot and further away from the structure S than the first nozzle 22, and blows an assist gas toward the optical path of the laser beam. The specific attachment position of the second nozzle 23, the spraying angle of the assist gas to the optical path, and the like may be appropriately determined so that the flying object including the melted material is quickly removed from the optical path of the laser beam.

The first nozzle 22 and the second nozzle 23 are made movable while maintaining the distance from the irradiation spot SP and the optical path of the laser beam along with the movement of the irradiation spot SP. Moreover, the number of installed first nozzles 22 and second nozzles 23 is not limited, and two or more nozzles may be installed.

Air, nitrogen, or the like is preferably used as the assist gas. The pressure and flow rate of the assist gas may be appropriately determined in consideration of the thickness and material of the asbestos-containing layer L to be removed. The flow rate of the assist gas is preferably in the range of 0.1 m ³ /min to 0.3 m ³ /min. Also, the pressure and flow rate of the assist gas may differ between the first nozzle 22 and the second nozzle.

(Suction means 3)
The suction means 3 includes a suction head 31 , a cyclone separator 32 , a HEPA (High Efficiency Particulate Air) filter 33 and an exhaust blower 34 .

The suction head 31 is arranged upstream of the irradiation spot SP in the direction of movement of the irradiation spot, and is movable together with the movement of the irradiation spot SP while maintaining a distance from the irradiation spot SP. As shown in FIG. 2, the suction head 31 is an isosceles trapezoidal box member when viewed from the direction perpendicular to the surface of the asbestos-containing layer L. is longer than the lower base on the upstream side in the movement direction, and the height in the direction away from the surface of the asbestos-containing layer L increases from the upstream side in the movement direction of the irradiation spot SP toward the downstream side in the movement direction. A suction opening 311 is formed on the side surface on the downstream side in the moving direction of the irradiation spot SP, that is, the surface facing the irradiation spot SP, and an exhaust opening 312 is formed on the side surface on the upstream side in the moving direction of the irradiation spot SP. The exhaust opening 312 of the suction head 31 and the intake port 321 of the cyclone separator 32 are connected by a pipe 91 .

The distance between the suction opening 311 of the suction head 31 and the irradiation spot SP and the amount of suction may be appropriately determined in consideration of the irradiation intensity of the laser light, the area of the irradiation spot SP, and the like.

The cyclone separator 32 has an intake port 321 protruding tangentially from the upper side wall of the separator, an exhaust port 322 protruding upward from the center of the upper surface of the separator, and a lower portion of the separator. It also has a dust collector 323 in which slag separated from the gas is collected.

The HEPA filter 33 is provided in the middle of the pipe 92 connecting the exhaust port 322 of the cyclone separator 32 and the exhaust blower 34 . The HEPA filter 33 separates fine dust, such as unmelted asbestos, from the gas discharged from the cyclone separator 32 so that environmentally safe gas is discharged from the exhaust blower 34 . A conventionally known one can be used as the HEPA filter 33 .

In addition, the removal device D is movable in a state in which the processing head 13, the first nozzle 22, the second nozzle 23, and the suction head 31 are fixed in positional relation to each other in the operation of melting and removing the asbestos-containing layer L. Other device configurations may be fixed at predetermined positions.

(Melting removal work)
The asbestos-containing layer L is a layer containing asbestos, and for example, the asbestos-containing layer L formed on the surface of the outer wall or inner wall of the structure S is a finish coating material layer containing asbestos and lime (CaO) or It may have a laminated structure of a foundation adjustment layer containing silica sand (SiO). In the removal apparatus and removal method of the present invention, when the asbestos-containing layer L has such a laminated structure, the base adjustment layer is melted and removed with the laser beam together with the finishing coating material layer.

Although there are several types of asbestos, chrysotile is mainly used for the asbestos-containing layers sprayed on the outer and inner walls of the structure S. Chrysotile has the highest melting point of 1500°C among asbestos. The melting point of lime contained in the asbestos-containing layer L is 2570°C, and the melting point of silica sand is 1700°C. Therefore, the heating temperature by the irradiation of the laser light must be higher than the highest melting point of the components contained in the asbestos-containing layer L (2570° C. or higher in the above case).

The structure S is mainly a structure such as a building, but is not limited thereto, and includes, for example, ships and vehicles.

In the removal of the asbestos-containing layer L by the removing device D having the configuration described above, first, the processing head 13, the first nozzle 22, the second nozzle 23, and the suction head 31 are arranged at predetermined positions. That is, the processing head 13 is arranged so that the asbestos-containing layer L is irradiated with laser light at a predetermined angle and an irradiation spot SP having a predetermined area is formed. Two nozzles 23 are positioned, and each is arranged so that the suction head 31 is positioned on the upstream side in the moving direction.

Next, a laser beam is emitted from the laser transmitter 11 and condensed by the processing head 13 to form an irradiation spot SP having a predetermined area on the asbestos-containing layer L. FIG. At this time, the compressor 21 is simultaneously operated, and the assist gas is blown from the first nozzle 22 toward the irradiation spot SP, and the assist gas is blown from the second nozzle 23 to the optical path of the laser beam. Further, the exhaust blower 34 is also actuated so that the suction head 31 sucks air around the irradiation spot SP.

The asbestos-containing layer L is melted by laser light emitted from the processing head 13 . Molten asbestos becomes slag mixed with lime (CaO), silica sand (SiO), etc., and is rendered harmless. The slag is blown off from the surface of the structure S by the assist gas and is sucked into the suction head 31 . Also, fine dust with a size of about 0.5 mm may be generated from the interface between the structure S and the asbestos-containing layer L. The amount of fine dust generated is several percent or less of the total amount removed, but the fine dust may contain unmelted asbestos. Such fine dust is also blown off from the surface of the structure S by the assist gas and is sucked into the suction head 31 .

The slag and fine dust sucked by the suction head 31 are separated by the cyclone separator 32 . That is, the slag having a high specific gravity falls into the dust collection section 323 at the bottom of the cyclone separator 32, and the fine dust having a specific gravity smaller than that of the slag is discharged from the exhaust port 322 of the cyclone separator 32 on the air current. Then, the airflow discharged from the cyclone separator 32 is sent to the HEPA filter 33, where fine dust in the airflow is collected. The gas that has passed through the HEPA filter 33 is discharged outside by an exhaust blower 34 . The exhaust gas is free of slag and fine dust, ensuring environmental safety.

The slag separated by the cyclone separator 32 is reused, for example, as recycled aggregate. Further, since the fine dust collected by the HEPA filter 33 may contain unmelted asbestos, it is melted into slag by a laser heating chamber, rendered harmless, and then reused as recycled aggregate or the like. .

(Second embodiment)
FIG. 3 shows a partial configuration diagram of the removing device according to the second embodiment. The removal device partly shown in FIG. The configuration of the head 35 is different from that of the removing device of the first embodiment. Hereinafter, the suction head 35 will be mainly described, and the same members as those in the first embodiment will be denoted by the same reference numerals, and the description thereof will be omitted.

The suction head 35 shown in FIG. 3 includes a head body 35a having an inverted bowl shape, in which a suction opening 351 is formed so as to face the structure S (or the asbestos-containing layer L), and a peripheral edge of the suction opening 351 of the head body 35a. and an elastic skirt portion 36 extending toward the structure S side. The head main body 35a has a cylindrical discharge opening 352 projecting outward, a first opening 353 into which the machining head 13 can be inserted, a second opening 354 into which the first nozzle 22 can be inserted, A third opening 355 into which the second nozzle 23 can be inserted is formed.

The processing head 13 is inserted into the first opening 353 so as to form an irradiation spot SP having a predetermined area at a predetermined angle with respect to the structure S (or the asbestos-containing layer L). The first nozzle 22 is inserted into the second opening 354 so as to be at a predetermined distance and height from the irradiation spot SP. The second nozzle 23 is inserted into the third opening 355 so as to have a predetermined distance from the optical path of the laser beam. To the discharge opening 352 is connected one end of a tube 91 whose other end is connected to the air inlet 321 of the cyclone separator 32 (shown in FIG. 1).

The skirt portion 36 is in contact with the structure S (or the asbestos-containing layer L), and the suction head 35 and the structure S are arranged so that no gap is formed between the suction head 35 and the structure S (or the asbestos-containing layer L). (or the asbestos-containing layer L).

The suction head 35 can be moved along with the movement of the processing head 13, the first nozzle 22 and the second nozzle 23 by moving means (not shown). In other words, the movement of the suction head 35 causes the processing head 13, the first nozzle 22 and the second nozzle 23 to move.

Further, if the inside of the head main body 35a is always kept at a negative pressure by the suction means 3, the skirt portion 36 may not be provided. Rather, a gap may be positively provided between the head main body 35a and the structure S (or the asbestos-containing layer L) so that air can flow into the head main body 35a from the outside. The slab can be more effectively removed from the surface of the structure S by utilizing the flow of the external atmosphere flowing into the head body 35a together with the gas injection from the first nozzle 22 and the second nozzle 23. FIG.

The asbestos-containing layer L formed on the surface of the structure S was removed by melting using the removal apparatus D shown in FIG. Specifically, the asbestos-containing layer L had a structure in which a finish coating material layer (containing asbestos) of 1.5 mm and a foundation adjustment layer (mortar layer) of 1.5 mm were laminated. Then, the degree of removal of the asbestos-containing layer L from the surface of the structure S was visually observed using a magnifying glass at moving speeds of the irradiation spot SP of the laser beam of 7 m/min, 10 m/min and 13 m/min. 4 and 5 show enlarged photographs of the surface of the structure S after the asbestos-containing layer L has been removed. The conditions for using the laser etc. are as follows.

(laser)
Laser power: 6kW
Irradiation spot SP shape: 6.5 mm square Focal position: -10 mm (changed by observation)
Irradiation angle: Advance angle 20° (changed by observation)
Moving speed (removal area per unit time): 7 m/min (2.94 m ² /h)
: 10m/min (4.20m ² /h)
: 13m/min (5.07m ² /h)
* Fine adjustment by observation so that the removal width of the asbestos-containing layer L is 7 mm and the removal depth is 2.5 mm to 3.0 mm.

(assist gas)
Type: Air pressure: 0.75 to 1.0 MPa
Flow rate: 120-260L/min
Injection angle: 70 degrees (from vertical)

(suction)
Suction volume: 26L/min

As is clear from FIG. 4, when the moving speed of the irradiation spot was changed to 7 m/min, 10 m/min, and 13 m/min, the asbestos-containing layer was almost completely removed at any moving speed. FIG. 5 is an enlarged photograph of the trace of removal of the asbestos-containing layer and the bottom of the trace of removal at a moving speed of 7 m/min. In FIG. 5, a thin layer of melted and vitrified material can be seen on the bottom surface of the asbestos-containing layer removal trace, and the structure under the thin layer can be seen through.

When the removal area of the asbestos-containing layer per unit time was calculated from the removal width of the asbestos-containing layer of 7 mm and the movement speed by the irradiation of these laser beams, 2.94 m ² /h, 4.20 m ^{2 /h, and 5.07 m 2 were} obtained. /h, and it was confirmed that high workability can be obtained.
From the above, if the laser output is set to 20 kW, which is practically usable, and the arrangement of the first nozzle 22 and the second nozzle 23, and the ejection pressure and flow rate are optimized, the removal area of the asbestos-containing layer per unit time is maximum 10 m. It is considered possible to increase the speed up to ² /h.

According to the removing method and removing apparatus of the present invention, the asbestos-containing layer formed on the surface of the structure can be removed in a shorter period of time than before. In addition, the asbestos-containing layer formed on the surface of the structure can be removed without providing a shielding space and without the worker wearing protective clothing.

1 laser irradiation means 2 gas injection means 3 suction means L asbestos-containing layer S structure 11 laser transmitter 12 fiber cable 13 processing head 21 compressor 22 first nozzle 23 second nozzle 31 suction head 32 cyclone separator 33 HEPA filter 34 Exhaust blower 35 Suction head 35a Head body 36 Skirt part SP Irradiation spot (irradiation part)

Claims (13)

A method for removing an asbestos-containing layer formed on the surface of a structure, comprising:
melting the asbestos-containing layer while relatively moving the irradiated portion of the laser beam with respect to the asbestos-containing layer on the surface of the structure;
A method for removing an asbestos-containing layer, comprising ejecting a gas onto a portion irradiated with a laser beam to remove a melt from the surface of the structure. 2. The method of removing an asbestos-containing layer according to claim 1, wherein the gas is jetted from the downstream side of the portion irradiated with the laser light in the moving direction. 3. The method of removing an asbestos-containing layer according to claim 1, wherein a gas is also injected into the optical path of said laser beam to remove flying objects including said melted matter from said optical path. 4. The method for removing an asbestos-containing layer according to any one of claims 1 to 3, wherein the flying object containing the melt is sucked together with gas. 5. The method of removing an asbestos-containing layer according to claim 4, wherein the flying object including the melted material is sucked together with the gas from the upstream side in the moving direction of the irradiated portion of the laser beam. 5. The method for removing an asbestos-containing layer according to claim 3 or 4, wherein the melted material is separated and recovered from the sucked material. An apparatus for removing an asbestos-containing layer formed on the surface of a structure,
Having a laser irradiation means and a gas injection means,
The laser irradiation means irradiates the asbestos-containing layer with a laser beam to melt the asbestos-containing layer,
The gas injection means includes a first nozzle that injects gas onto the irradiated portion of the laser beam to remove the melted material from the surface of the structure,
An apparatus for removing an asbestos-containing layer, wherein the portion irradiated with the laser beam is movable relative to the structure. 8. The apparatus for removing an asbestos-containing layer according to claim 7, wherein the first nozzle injects gas from the downstream side of the portion irradiated with the laser beam in the moving direction to the portion irradiated with the laser beam. 9. The apparatus for removing an asbestos-containing layer according to claim 7, wherein said gas injection means comprises a second nozzle for injecting gas into the optical path of said laser beam to remove flying objects including said melt from said optical path. further comprising suction means;
10. The apparatus for removing an asbestos-containing layer according to claim 7, wherein the suction means sucks the flying object containing the melt together with gas. said suction means comprises a suction head having a suction opening and a discharge opening;
11. The apparatus for removing an asbestos-containing layer according to claim 10, wherein the suction head is arranged such that the suction opening faces the laser beam irradiation portion from the upstream side in the moving direction of the laser beam irradiation portion. said suction means comprises a suction head having a suction opening and a discharge opening;
The suction opening is provided to face the structure,
11. The apparatus for removing an asbestos-containing layer according to claim 10, wherein the suction head is arranged so as to cover at least the portion irradiated with the laser beam and its surroundings. further having separation and recovery means;
13. The apparatus for removing an asbestos-containing layer according to claim 10, wherein said separating and recovering means separates and recovers the melted material from the sucked matter sucked by said sucking means.

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