JP7490413B2 - Asbestos Removal Methods - Google Patents

Description

The present invention relates to an asbestos removal method for removing asbestos sprayed onto the inner surface of a chimney.

The inside of the chimney is sprayed with Level 1 asbestos-containing spray material, which is the most dust-generating type. Level 1 asbestos-containing spray material has more exposed fibers than other asbestos materials, and is brittle when used alone, with low hardness and specific gravity. For this reason, dust is relatively easy to scatter, and it has the characteristic of being broken by even a small amount of external pressure.
In other words, when working to remove Level 1 asbestos, strict exposure control measures are required, such as isolating the work area and using dust masks and protective clothing according to the high dust concentration.

So, as a method for removing level 1 asbestos sprayed on the inner surface of a chimney, for example, the method shown in FIG. 8 has been known. As shown in FIG. 8, a scaffolding 400 is set up along the side of a chimney 300 installed on a building 900. In addition, a scaffolding 401 is set up on the roof of the building 900, and an isolation area 500 is set up on the top of the scaffolding 400, 401. The entire inner surface of the isolation area 500 is covered with a protective sheet. A high-pressure water supply device 200 is installed on the ground, and a high-pressure hose 101 connected to the high-pressure water supply device 200 extends to the inside of the chimney 300 via pulleys 102, 102 installed in the isolation area 500 so that it can ascend and descend. An asbestos removal device 100 is connected to the tip of the high-pressure hose 101, and the asbestos removal device 100 can ascend and descend inside the chimney 300 via the high-pressure hose 101.

An isolation area 700 is formed on the side of the lower part of the chimney 300. The entire inner surface of the isolation area 700 is covered with a protective sheet. The isolation area 700 is connected to an opening 301 formed in the lower part of the chimney 300. A suction device 600 is disposed in the isolation area 700 to suck up the asbestos discharged from the opening 301. A security zone 800 is disposed next to the isolation area 700, and an air shower device 801 is disposed in the security zone 800.

The asbestos removal device 100 rotates horizontally while spraying high-pressure water supplied from the high-pressure water supply device 200 onto the inner surface of the chimney 300, removing the asbestos sprayed onto the inner surface of the chimney 300. The worker enters the isolation area 500 and operates the high-pressure hose 101 to raise and lower the asbestos removal device 100. The worker also enters the isolation area 700 wearing a dust mask and protective clothing, scrapes out the asbestos that has fallen below the chimney 300 into the isolation area 700 through the opening 301, and sucks up the scraped out asbestos using the suction device 600. After performing the asbestos suction work, the worker enters the security zone 800 and uses the air shower device 801 to blow air over his entire body, removing the asbestos that has adhered to his entire body.

Utility Model Registration No. 3197063

However, in the conventional asbestos removal method described above, there is a risk that workers may inhale the removed asbestos if they work for long periods of time in the closed isolation area 700.
In addition, working in a closed room when the temperature is high and wearing dust masks and protective clothing means working in a space contaminated with asbestos and being drenched in sweat, making it extremely tough work.
In other words, conventional asbestos removal methods posed a high risk of harming the health of workers.
Furthermore, in conventional asbestos removal methods, in order to prevent the removed asbestos particles from scattering to the outside from the tip of the chimney 300, it is necessary to provide an isolation area 500 at the tip of the chimney 300 and to cover the entire inner surface of the isolation area 500 with a protective sheet.
Furthermore, the above-mentioned asbestos removal method requires the installation of a security zone 800 and an air shower device 801 .
In other words, the above-mentioned asbestos removal method has a problem of high work costs.
In addition, the above-mentioned asbestos removal method has the problem that it is difficult to work for long periods of time in the closed isolation area 700, and therefore work must be interrupted or workers must be replaced periodically, resulting in poor work efficiency.

The present invention was created as a result of extensive research to solve the above-mentioned problems, and aims to provide an asbestos removal method that does not pose a risk to the health of workers. Another aim of the present invention is to provide an asbestos removal method that can reduce work costs and improve work efficiency.

(First Invention)
In order to achieve the above-mentioned object, the asbestos removal method according to the first aspect of the present invention comprises:
An asbestos removal method for removing asbestos sprayed onto the inner surface of a chimney (10), comprising the steps of:
An opening (12) communicating with the inside and outside of the chimney (10) is formed at the bottom of the chimney (10);

A scattering inhibitor for suppressing scattering of asbestos;
a removal device (25) for removing the asbestos by spraying high-pressure water onto the asbestos sprayed on the inner surface of the chimney (10);
A suction and recovery device (51, 81) that sucks and recovers the asbestos removed from the inner surface of the chimney (10);
a blocking member (70) having an insertion hole (72) through which a suction hose (52) connected to a suction recovery device (51, 81) can be inserted and capable of blocking the opening (12);

A filling step (step 2) of foaming the anti-scattering agent and filling the inside of the chimney (10);
a removal process (process 5) in which, after the filling process (process 2), a removal device (25) for spraying high-pressure water is moved inside the chimney (10) while spraying high-pressure water to remove the asbestos, and the removed asbestos (As) accumulated in the lower part of the chimney (10) is sucked and collected by a suction collection device (51, 81) using a suction hose (52) inserted into the insertion hole (72) of a blocking member (70) that blocks the opening (12) ;

In addition
The blocking member (70) is
A vent (77) communicating with the inside and outside of the chimney (10);
The method is characterized by comprising a filter (78) provided in the ventilation hole (77) for filtering out the asbestos particles removed in the removal process (step 5) .

( Second Invention)
The second invention of the present application is the above-mentioned first asbestos removal method,
The removal step (step 5) is
This is characterized by placing a lid (26) on the tip of the chimney (10).

Note that the symbols and phrases in parentheses above indicate the corresponding relationship to the specific means described in the embodiments described below.

(Effects of the First Invention)
According to the first invention of the present application, a filling process is included in which the scattering inhibitor is foamed and filled inside the chimney, so that the scattering inhibitor permeates the asbestos, and therefore it is also possible to prevent the removed asbestos from scattering.
Furthermore, even if asbestos that has not been permeated with the anti-scattering agent is removed and asbestos particles that can scatter are generated, the inside of the chimney is filled with a foam-like anti-scattering agent, and the foam-like anti-scattering agent adheres to the asbestos particles, preventing the asbestos particles from scattering from the tip of the chimney to the outside.
In addition, when the removed asbestos is collected, the asbestos particles can be prevented from scattering.
Therefore, there is no risk of workers recovering the removed asbestos inhaling asbestos particles and damaging their health.
Furthermore, since it is no longer necessary to provide an isolation area at the tip of the chimney and cover the entire inner surface of that isolation area with a protective sheet, as was done in the past, work costs can be reduced accordingly .

Furthermore , the opening formed in the lower part of the chimney can be blocked with a blocking member, and the asbestos can be sucked up by a suction hose inserted through the blocking member.
Therefore, there is no risk of workers recovering the removed asbestos inhaling asbestos particles and damaging their health.
In addition, since there is no need for an isolation area connected to the opening formed at the bottom of the chimney, a security zone adjacent to the isolation area, and an air shower device in the security zone, as was necessary in the conventional system, operating costs can be reduced accordingly.
Moreover, there is no need to periodically interrupt work in the isolated area or replace workers, which improves work efficiency.

Furthermore , since the blocking member has an air vent that communicates between the inside and outside of the chimney, it is possible to create a negative pressure inside the chimney.
Therefore, the efficiency of the suction device in suctioning asbestos can be improved, thereby improving work efficiency.
Furthermore, a filter that filters out the asbestos particles removed during the removal process is installed in the ventilation hole, preventing asbestos from leaking out of the chimney through the ventilation hole, thereby ensuring safety.

(Effects of the second invention)
According to the second invention of the present application, the asbestos can be removed by covering the tip of the chimney, thereby taking every precaution to prevent the removed asbestos particles from scattering from the tip of the chimney.
Furthermore, since the negative pressure inside the chimney can be increased, the efficiency of the suction device in suctioning asbestos can be further improved, thereby further improving work efficiency.

FIG. 1 is an explanatory diagram of an asbestos recovery system for carrying out an asbestos removal method according to an embodiment of the present invention. FIG. 2 is an explanatory diagram of a suction device provided in the asbestos recovery system shown in FIG. 1 . 2A and 2B are explanatory diagrams of a blocking member provided in the asbestos recovery system shown in FIG. 1, in which (A) is a front view of the blocking member, and (B) is a plan view of the blocking member. 4 is a plan view illustrating a method of using the closing member shown in FIG. 3. FIG. 4 is a side view illustrating a method of using the closing member shown in FIG. 3. FIG. FIG. 2 is a process diagram of an asbestos removal method according to an embodiment of the present invention. 3 is a flowchart showing a flow of processing executed by a control unit provided in the suction device shown in FIG. 2 . FIG. 1 is an explanatory diagram showing a conventional asbestos removal method.

[Configuration of asbestos recovery system]
The configuration of an asbestos recovery system for carrying out the asbestos removal method of this embodiment will be described with reference to Fig. 1. Fig. 1 is an explanatory diagram of an asbestos recovery system 1.

A chimney 10 is provided on a building 90. The chimney 10 has a cylindrical wall 11 with an open tip. Level 1 asbestos is sprayed on the inner surface of the wall 11. A scaffolding 91 is set up on the side of the chimney 10, and a scaffolding 92 is set up on the roof of the building 90. A work room 40 is provided on top of the scaffolding 92. A pulley 23, 24 is provided in the work room 40. A work vehicle 20, a work vehicle 50, and a work vehicle 80 are arranged near the chimney 10. A high-pressure water supply device 21 and a scattering inhibitor supply device 30 are mounted on the work vehicle 20. A converter 32 that converts a liquid scattering inhibitor into a foam-like form is connected to the tip of a hose 31 connected to the scattering inhibitor supply device 30. The converter 32 is inserted without any gaps into a lid 26 that closes the tip of the chimney 10. The liquid anti-scattering agent supplied from the anti-scattering agent supply device 30 is converted into foam by a converter 32, and the foam 33 of the anti-scattering agent converted into foam is supplied to the inside of the chimney 10 and fills the inside of the chimney 10 over a predetermined period of time.
The type of scattering inhibitor is not limited as long as it can effectively suppress the scattering of asbestos particles, and for example, water-soluble resins whose main components are polyvinyl alcohol, urethane resins, and acrylic resins can be used.

A high-pressure hose 22 connected to the high-pressure water supply device 21 extends into the inside of the chimney 10 via pulleys 23 and 24, and a removal device 25 for removing asbestos is connected to the tip of the high-pressure hose 22. The removal device 25 sprays high-pressure water supplied from the high-pressure water supply device 21 onto the inner surface of the wall 11 of the chimney 10, and removes the asbestos sprayed onto the inner surface by the water pressure. A known device (for example, a cylindrical structure inner wall cleaning device described in JP 2008-149264 A) can be used as the removal device 25. The removal device 25 includes a base, spray nozzles extending radially from the base toward the wall 11 of the chimney 10, and an air motor for rotating the base in a horizontal direction. Each spray nozzle sprays high-pressure water supplied from the high-pressure water supply device 21 via the high-pressure hose 22 onto the inner surface of the wall 11 of the chimney 10, and removes the asbestos sprayed onto the inner surface of the wall 11 by water pressure. The removal device 25 has the capacity to spray high-pressure water of, for example, 245 MPa, with a maximum discharge flow rate of 50 liters/minute. The work vehicle 20 is also equipped with a compressed air supply device (not shown) that supplies compressed air to the air motor provided in the removal device 25.

An opening 12 that communicates with the inside and outside of the chimney 10 is formed in the wall 11 at the bottom of the chimney 10, and a blocking member 70 that blocks the opening 12 is attached to the opening 12. A suction hose 52 that sucks up the asbestos As that has accumulated at the bottom of the chimney 10 and is mixed with water and a scattering inhibitor is inserted into the blocking member 70. The suction hose 52 is connected to an asbestos recovery device 51 mounted on a work vehicle 50. The asbestos recovery device 51 is connected to a suction device 81 mounted on a work vehicle 80 via a suction hose 53. The suction device 81 has a function of removing asbestos and the scattering inhibitor from the asbestos mixed with the sucked water and scattering inhibitor. The suction device 81 is equipped with an exhaust pipe 82 for exhausting the gas sucked in together with the asbestos to the atmosphere.

In this embodiment, a HEPA filter (not shown) is attached to the exhaust pipe 82. A HEPA filter is an air filter specified in JIS Z8122, which has a particle collection rate of 99.97% or more for particles with a particle size of 0.3 μm at the rated air volume, and has an initial pressure loss of 245 Pa or less. In other words, by using a HEPA filter as the filter 78, it is possible to filter out 99.97% or more of asbestos particles with a diameter of 0.3 μm or less, so there is no risk of workers inhaling asbestos particles discharged into the atmosphere from the ventilation opening 77 and causing damage to their health.

As described above, the asbestos recovery system 1 of this embodiment includes a removal device 25 that sprays high-pressure water on the inner surface of the chimney 10 to remove asbestos, a high-pressure water supply device 21 that supplies high-pressure water to the removal device 25, a scattering inhibitor supply device 30 that supplies a scattering inhibitor that suppresses scattering of asbestos, a converter 32 that converts the scattering inhibitor supplied from the scattering inhibitor supply device 30 into a foam-like scattering inhibitor and supplies it to the inside of the chimney 10, a blocking member 70 that blocks the opening 12 formed at the bottom of the chimney 10, a suction hose 52 inserted into the blocking member 70, an asbestos recovery device 51 to which the suction hose 52 is connected, and a suction device 81 connected to the asbestos recovery device 51. The asbestos recovery device 51 and the suction device 81 are examples of the suction recovery device of the present invention.

(Closure member)
Here, the structure of the blocking member 70 will be described with reference to FIG.
The blocking member 70 is formed in a shape that matches the opening 12 formed in the wall 11 at the bottom of the chimney 10. In this embodiment, the opening 12 is formed in a rectangular shape, and the blocking member 70 is formed in a rectangular plate shape that matches the opening 12. The blocking member 70 has a rectangular plate-shaped main body 71 that matches the opening 12. The main body 71 has an insertion hole 72 formed through the main body 71 for inserting the suction hose 52, a first through hole 73, a second through hole 74, an air vent 77, and a filter 78 attached to the air vent 77. In this embodiment, the filter 78 is the above-mentioned HEPA filter. The main body 71 is formed transparently from a synthetic resin such as acrylic.

A first glove 75 to be worn on the left arm of the worker P protrudes from the first through-hole 73, and a second glove 76 to be worn on the right arm of the worker P protrudes from the second through-hole 74. The first glove 75 and the second glove 76 are each structured to seal at least the area from the part closer to the shoulder than the elbow to the fingertips. The periphery of the first glove 75 is in close contact with the periphery of the first through-hole 73, and no gap is formed between the first glove 75 and the first through-hole 73. The periphery of the second glove 76 is in close contact with the periphery of the second through-hole 74, and no gap is formed between the second glove 76 and the second through-hole 74.

That is, the main body 71, the first glove 75, and the second glove 76 can be constructed using a so-called glove box structure. A glove box is an airtight container designed to allow only hands to be inserted inside so that work can be performed in a condition isolated from the outside air. A skirt portion 72a having a smaller diameter than the diameter of the insertion hole 72 is formed from the periphery of the insertion hole 72. In this embodiment, the skirt portion 72a is made of rubber and is in close contact with the outer circumferential surface of the suction hose 52 inserted into the insertion hole 72, so that no gap is formed between the suction hose 52 and the insertion hole 72.
In other words, the blocking member 70 is structured so that asbestos does not leak out of the chimney 10 through the opening 12 when asbestos suction work is being performed.
Furthermore, since the main body 71 is transparent, the position of the suction hose 52 can be visually confirmed from outside the blocking member 70 during the asbestos suction operation.

(Asbestos recovery equipment)
Here, the configuration of the asbestos recovery device 51 will be described with reference to FIG.
The asbestos recovery device 51 is a device that recovers asbestos sucked by a suction hose 52. The asbestos recovery device 51 includes a hopper 54, a first sensor 55, a valve device 56, a sealing device 57, a coagulant supplying device 58, a filter 59, a recovery bag 61, a second sensor 62, and a control unit 64.

The hopper 54 is provided between the suction hose 52 and the suction hose 53 connected to the suction device 81 (FIG. 1). The suction hose 53 is attached to the top of the hopper 54. This prevents the mixture of asbestos, water and scattering inhibitor discharged from the suction hose 52 from directly entering the suction hose 53 with the force of suction. A filter 59 is provided at the connection point between the hopper 54 and the suction hose 53 to filter the asbestos sucked into the inside of the hopper 54. If the mesh of the filter 59 is made finer, the suction power decreases, and if the mesh is made coarser, the particles of asbestos that are not filtered become larger, so the type of filter 59 is determined taking into consideration the suction power and filtering capacity. For example, a wire mesh such as a demister can be used as the filter 59.
The first sensor 55 is a sensor that detects when the amount of asbestos accumulated in the hopper 54 reaches a predetermined amount. For example, the first sensor 55 is a proximity sensor. A limit switch may be used instead of the proximity sensor. Normally, the bottom of the hopper 54 is open, and the asbestos accumulated in the hopper 54 falls into a collection bag 61 arranged below the hopper 54.

The collection bag 61 is placed on a second sensor 62 that detects when the weight of the collection bag 61 reaches a predetermined amount. For example, the collection bag 61 is made of a material that does not leak asbestos particles, such as polyethylene. When the thickness of the collection bag 61 is thin, the collection bag 61 is doubled to prevent breakage and prevent asbestos from leaking. In this embodiment, the capacity of the collection bag 61 is a capacity that allows the collected asbestos to be lifted, for example, 20 to 40 liters, since the collection bag 61 is basically lifted by hand and collected by an operator. In addition, when a collection bag 61 with a larger capacity (for example, 1 cubic meter) is used, the collection bag 61 made of polyethylene or the like may be placed in a bag commonly called a FIBC (a registered trademark of National Marine Plastics Co., Ltd., an abbreviation for flexible container bag) and transported using a crane or the like.
A valve device 56 is provided at the bottom of the hopper 54 to open and close the bottom of the hopper 54. The valve device 56 is normally open, and closes when the second sensor 62 detects that the weight of the collection bags 61 has reached a predetermined amount, thereby blocking the bottom of the hopper 54. For example, the valve device 56 includes a shutter-type or butterfly-type valve and an actuator such as a solenoid or a motor that drives the valve to open and close. The second sensor 62 is, for example, a weight sensor.

Below the valve device 56, a sealing device 57 is provided to seal the upper opening of the collection bag 61. In this embodiment, the sealing device 57 is a heat-type or ultrasonic welding device that seals the opening of the collection bag 61 to prevent asbestos from leaking. The sealing device 57 operates after the valve device 56 is closed to seal the opening of the collection bag 61. The sealing device 57 is also configured to allow the collection bag 61 to be attached and detached. The sealing device 57 may be configured to set the collection bag 61 so that the longitudinal surfaces constituting the opening of the collection bag 61 face each other, and to weld the opposing longitudinal surfaces to each other. The sealing device 57 may also be configured to set the opening of the collection bag 61 to be circular, narrow the opening, and then tie it with a binding member. It may also be configured to weld the narrowed portion of the opening.

The coagulant supply device 58 is connected to the sealing device 57 by a hose 60. A spray nozzle 65 is attached to the tip of the hose 60, which sprays a coagulant that coagulates the asbestos mixed in water. The spray hole of the spray nozzle 65 faces the inside of the collection bag 61 from a predetermined member that constitutes the sealing device 57. The coagulant supply device 58 sprays the coagulant from the spray nozzle 65 into the inside of the collection bag 61, coagulating the asbestos that has accumulated in the collection bag 61 and is mixed with water. The type and concentration of the coagulant are adjusted so that the asbestos does not scatter into the atmosphere from the opening of the collection bag 61. The second sensor 62 and the coagulant supply device 58 are arranged on a base 63. For example, a polymeric polymer can be used as the coagulant.

The control unit 64 is connected to the valve device 56, the sealing device 57, the coagulant supply device 58, and the suction device 81, and controls each of the connected devices. The control unit 64 is equipped with a ROM that stores control programs and tables for controlling each device, a RAM that expands and stores the control programs read from the ROM, and a CPU that executes the control programs expanded in the RAM. The RAM also temporarily stores the processing results of the CPU, etc.

[Asbestos removal method]
Next, the asbestos removal method will be described with reference to FIG.
(Step 1)
First, preparations are made for removing asbestos. Specifically, as shown in Fig. 1, scaffolding 91 is erected on the side of the chimney 10, and scaffolding 92 is erected on the roof of the building 90 on which the chimney 10 is installed so as to surround the tip of the chimney 10. A work room 40 is also installed on the scaffolding 92, and pulleys 23 and 24 are attached to the work room 40. Furthermore, work vehicles 20, 50, and 80 are placed near the chimney 10. Furthermore, a lid 26 is placed on the tip of the chimney 10 to close the tip of the chimney 10, and a converter 32 is inserted through the lid 26 without any gaps. Furthermore, an opening 12 formed in a wall 11 at the bottom of the chimney 10 is closed without any gaps by a closing member 70.

(Step 2)
Next, the high-pressure hose 22 is hung between the pulleys 23 and 24, and the high-pressure hose 22 is connected to the removal device 25. Next, the removal device 25 is lowered to the bottom of the chimney 10.

(Step 3)
Next, the scattering inhibitor is supplied from the scattering inhibitor supply device 30 to the converter 32, which converts the scattering inhibitor into a foam, and the foamed scattering inhibitor is filled into the chimney 10. The time required for the foamed scattering inhibitor to fill the chimney 10 can be determined in advance by experimentation depending on the volume of the chimney 10, the amount of scattering inhibitor per unit time discharged by the converter 32, and the like. Step 3 is an example of a filling step of the present invention.

(Step 4)
Next, a predetermined time is waited until the foam-like anti-scattering agent penetrates into the asbestos sprayed on the inner surface of the wall 11 of the chimney 10. This predetermined time can be determined in advance by experimentation depending on the type or thickness of the asbestos being sprayed.

(Step 5)
Next, the high-pressure water supply device 21 is operated to supply high-pressure water to the removal device 25 via the high-pressure hose 22. Also, the compressed air supply device is operated to supply compressed air to the air motor of the removal device 25. As a result, each spray nozzle of the removal device 25 sprays high-pressure water onto the inner surface of the wall 11 of the chimney 10 while rotating horizontally, thereby removing the asbestos.

The suction device 81 and asbestos recovery device 51 are also operated to suck up the asbestos As that has been removed and accumulated at the bottom of the chimney 10 and is mixed with water and a scattering inhibitor, and the asbestos As is recovered in the asbestos recovery device 51. As described above, the worker P performing the asbestos As suction work inserts his left arm into the first glove 75 (Figure 3) and his right arm into the second glove 76. Then, as shown in Figures 4 and 5, the worker P operates the suction hose 52 with both hands, and the asbestos As accumulated at the bottom of the chimney 10 is sucked up by the suction hose 52.

While removing the asbestos, the removal device 25 is raised above the chimney 10 at a predetermined rising speed. The removal device 25 is raised by a worker in the work room 40 or a worker near the work vehicle 20 by pulling up the high-pressure hose 22. Alternatively, a wire for lifting the removal device 25 can be attached to the removal device 25, and a winding device for winding up the wire can be placed in the work room 40 or on the ground, and the removal device 25 can be raised by operating the winding device. The rising speed of the removal device 25 can be determined in advance by experimentation depending on the removal capacity of the removal device 25, the type of asbestos, the thickness of the asbestos, etc. Process 5 is an example of a removal process of the present invention.

(Step 6)
Next, the inside of the chimney 10 is photographed to confirm the state of asbestos removal. For example, a camera and lighting fixture are attached to the wire that was suspending the removal device 25, and the camera and lighting fixture are raised and lowered inside the chimney 10 to photograph the inner surface of the chimney 10, and the photographed image is displayed on a monitor installed at the work site, and the image is viewed to confirm the state of asbestos removal. If it is found that asbestos remains, steps 2 to 6 are performed again. In this case, if the remaining asbestos has been permeated with the scattering inhibitor, steps 3 and 4 may be omitted, and only steps 2, 5, and 6 may be performed.

(Step 7)
Next, the scattering inhibitor is coated on the inner surface of the chimney 10. For example, the scattering inhibitor is injected from each injection nozzle of the removal device 25 onto the inner surface of the chimney 10. Alternatively, an injection nozzle for injecting the scattering inhibitor may be attached to the removal device 25, and the scattering inhibitor may be injected from the injection nozzle onto the inner surface of the chimney 10. In this case, the injection speed of the scattering inhibitor does not need to be the same as that when high-pressure water is injected to remove asbestos, as long as the injected scattering inhibitor reaches the inner surface of the chimney 10. Alternatively, instead of the removal device 25, a dedicated device for injecting the scattering inhibitor may be suspended inside the chimney 10, and the dedicated device may be raised and lowered while injecting the scattering inhibitor.

[Processing contents of the control unit]
Next, the process executed by the control unit 64 (FIG. 2) in the above-mentioned step 5 will be described with reference to FIG. 7. In the following description, the process steps executed by the control unit 64 are abbreviated as S.

The control unit 64 outputs an operation command to the suction device 81 (FIG. 1) to start suctioning the asbestos (S1). This process of S1 starts when a suction switch (not shown) connected to the control unit 64 is turned on. This suction switch can also be placed near the worker who operates the suction hose 52. Next, the control unit 64 determines whether the first sensor 55 (FIG. 2) is turned on (S2), and if it is determined that the first sensor 55 is not turned on (S2: No), it closes the valve device 56 (FIG. 2) and closes the bottom of the hopper 54 (S3). In other words, the control unit 64 keeps the valve device 56 in a closed state until the amount of asbestos accumulated in the hopper 54 reaches a predetermined amount at which the first sensor 55 is turned on, and controls the hopper 54 so that a predetermined amount of asbestos is accumulated.

If the control unit 64 determines that the first sensor 55 is turned on (S2: Yes), it opens the valve device 56 and opens the bottom of the hopper 54 (S4). That is, when the amount of asbestos accumulated in the hopper 54 reaches a predetermined amount at which the first sensor 55 is turned on, the control unit 64 opens the valve device 56 and drops the asbestos accumulated in the hopper 54 into the collection bag 61. Next, the control unit 64 operates the coagulant supply device 58 provided in the asbestos collection device 51 and sprays the coagulant from the spray nozzle 65 into the inside of the collection bag 61 (S5). Next, the control unit 64 determines whether the second sensor 62 (FIG. 2) is turned on (S6), and if it is determined that the second sensor 62 is turned on (S6: Yes), it closes the valve device 56 (S7). In other words, when the control unit 64 determines that the amount of asbestos collected in the collection bag 61 has reached a predetermined weight, it closes the bottom of the hopper 54 to prevent the asbestos accumulated in the hopper 54 from falling into the collection bag 61.

Furthermore, if the control unit 64 determines that the second sensor 62 is not on (S6: No), it executes S1 to S5. In other words, the control unit 64 continues suction of the asbestos and spraying of the coagulant until it determines that the amount of asbestos collected in the collection bag 61 has reached a predetermined weight.
Then, the control unit 64 stops the suction device 81 and the coagulant supply device 58 (S8), and stops the suction of asbestos and the spraying of the coagulant. Next, the control unit 64 activates the sealing device 57 (FIG. 2) (S9), and seals the opening of the collection bag 61. Next, the control unit 64 notifies that the collection bag 61 is full of asbestos (S10). For example, the control unit 64 is connected to an alarm lamp and an alarm speaker that notify that the collection bag 61 is full of asbestos, and the alarm lamp is turned on and a predetermined sound is output from the alarm speaker to notify surrounding workers that the collection bag 61 is full of asbestos. The alarm lamp and the alarm speaker can also be disposed near the worker who operates the suction hose 52.

The worker removes the collection bag 61 from the sealing device 57 and carries the collection bag 61 to a prescribed location. At this time, since the opening of the collection bag 61 is sealed by the sealing device 57, there is no risk of asbestos leaking from the collection bag 61 to the outside, and therefore there is no risk of harm to the health of the worker carrying the collection bag 61 or people in the vicinity.
Then, if the asbestos collection work is to continue, the worker sets a new collection bag 61 in the sealing device 57, turns on the suction switch (not shown) connected to the control unit 64, and causes the control unit 64 to execute the above-mentioned S1 to S10.

[Effects of the embodiment]
(1) According to the asbestos removal method of the above-described embodiment, a process 3 (filling process) is included in which the scattering inhibitor is foamed and filled into the inside of the chimney. Since the scattering inhibitor permeates the asbestos, scattering of the removed asbestos can also be suppressed.
Furthermore, even if asbestos that has not been permeated with the scattering inhibitor is removed and asbestos particles that can scatter are generated, the inside of the chimney 10 is filled with a foam-like scattering inhibitor, and the foam-like scattering inhibitor adheres to the asbestos particles, thereby preventing the asbestos particles from scattering from the tip of the chimney 10 to the outside of the chimney 10.
In addition, there is no risk of workers in the work room 40 arranged at the tip of the chimney 10 inhaling asbestos and damaging their health.
Therefore, there is no risk of workers recovering the removed asbestos inhaling asbestos particles and damaging their health.
Furthermore, since it is not necessary to provide an isolation area 500 at the tip of the chimney 300 and cover the entire inner surface of the isolation area 500 with a protective sheet as in the conventional method, the operating costs can be reduced accordingly.

(2) Furthermore, according to the asbestos removal method of the above-mentioned embodiment, the opening 12 formed at the bottom of the chimney 10 can be blocked with a blocking member 70, and asbestos As can be sucked up by a suction hose 52 inserted into the blocking member 70.
Therefore, there is no risk of workers recovering the removed asbestos inhaling asbestos particles and damaging their health.
In addition, since there is no need for the isolation area 700 communicating with the opening 12 formed at the bottom of the chimney 10, the security zone 800 provided next to the isolation area 700, and the air shower device 801 provided in the security zone 800 as in the conventional method, operating costs can be reduced accordingly.
Furthermore, work efficiency can be improved since there is no need to periodically interrupt work in the isolated area or rotate workers.

(3) Furthermore, according to the asbestos removal method of the above-described embodiment, the suction hose 52 inserted into the blocking member 70 can be operated while wearing gloves (75, 76) on both arms to suck up the asbestos As accumulated at the bottom of the chimney 10.
Moreover, since the worker operating the suction hose 52 wears gloves (75, 76) on both arms, there is no risk of asbestos coming into contact with the worker's skin, and the safety of the worker can be ensured.
Therefore, there is no risk of health damage to workers recovering the removed asbestos by inhaling asbestos particles or having asbestos adhere to their skin.
In addition, as compared with the case where the suction hose 52 is fixed without being operated during the work, the asbestos As can be sucked up more efficiently, and the work efficiency can be improved.

(4) Furthermore, according to the asbestos removal method of the above-mentioned embodiment, the blocking member 70 is provided with an air vent 77 that connects the inside and outside of the chimney 10, so that the inside of the chimney 10 can be made to have a negative pressure.
Therefore, the suction efficiency of the suction device 81 can be improved, and the work efficiency can be improved.
Furthermore, since a filter 78 for filtering out the asbestos As particles removed in step 5 (removal step) is provided in the ventilation opening 77, it is possible to prevent the asbestos As from leaking from the ventilation opening 77 to the outside of the chimney 10, thereby ensuring safety.

(5) Furthermore, according to the asbestos removal method of the above-described embodiment, the asbestos can be removed by placing a lid 26 on the tip of the chimney 10, so that every precaution can be taken to prevent the removed asbestos As particles from scattering from the tip of the chimney 10.
Furthermore, since the negative pressure inside the chimney 10 can be increased, the suction efficiency of the suction device 81 can be further improved, and the work efficiency can be further improved.

(6) Furthermore, according to the asbestos removal method of the above-described embodiment, the removed asbestos As can be collected by suction while the tip of the chimney 10 is closed and the opening 12 is also closed. In other words, the removed asbestos As can be collected without leaking from the chimney 10 at all.
Furthermore, there is absolutely no risk of workers coming into contact with asbestos As during the processes of removing, sucking and recovering the asbestos.
Therefore, according to the asbestos removal method of the above-mentioned embodiment, work can be carried out at a level 3 work level, and there is no need to take measures such as those for levels 1 and 2, so there is no risk of harm to the health of workers.
In addition, it is possible to reduce work costs because there is no need to isolate the work site and workers do not need to wear masks that correspond to Level 1 or Level 2. Furthermore, since there is no need to isolate the work site and create a working environment, work time can be shortened accordingly.

(7) Furthermore, according to the asbestos removal method of the above-described embodiment, after the step of removing asbestos from the chimney 10, a step 7 is included in which an agent for inhibiting scattering is coated on the inner surface of the chimney 10. This makes it possible to prevent asbestos remaining on the inner surface of the chimney 10 from scattering when the chimney 10 is dismantled.
Therefore, workers dismantling the chimney 10 can be prevented from inhaling asbestos and damaging their health.

Other Embodiments
(1) The relationship between external factors such as the type of asbestos sprayed on the inner surface of the chimney 10, the thickness of the asbestos, the time it takes for the foam-like scattering inhibitor to penetrate the asbestos, and the volume of the chimney 10 and the volume of the foam-like scattering inhibitor required to fill the chimney 10 can be determined through experiments, and once the above external factors are known, the required volume of scattering inhibitor can be determined.
For example, the correspondence between the above external factors and the volume of anti-scattering agent can be stored in a table in the RAM of the control unit 64, and when each value of the above external factors is input from an input unit (e.g., a numeric input key) connected to the control unit 64, the control unit 64 can refer to the table in the RAM and display the volume of anti-scattering agent corresponding to the input external factor on a display unit (e.g., a liquid crystal display device) connected to the control unit 64.
In addition, the scattering inhibitor supply device 30 can be configured to automatically stop supplying the scattering inhibitor when the volume of scattering inhibitor supplied by the scattering inhibitor supply device 30 reaches the required volume described above.

(2) Before asbestos As is sucked up by the suction hose 52, a coating process can be added in which a scattering inhibitor is sucked up by the suction hose 52 and the inner surface of the suction hose 52 is coated with the scattering inhibitor. By adding this coating process, when the suction hose 52 is removed after asbestos As has been sucked up, it is possible to prevent asbestos As remaining inside the suction hose 52 from leaking out from the tip of the suction hose 52, so there is no risk of health damage to workers at the work site due to inhaling asbestos. The inner surface of the suction hose 53 can also be coated with a scattering inhibitor.

(3) A converter 32 can be attached to the removal device 25, and the removal device 25 can be raised and lowered inside the chimney 10 while spraying foam-like anti-scattering agent from the converter 32, filling the inside of the chimney 10 with the foam-like anti-scattering agent. Also, the anti-scattering agent can be sprayed onto the inner surface of the chimney 10 from each spray nozzle provided on the removal device 25, and the sprayed anti-scattering agent can be allowed to penetrate the asbestos. In this case, some spray nozzles can be made to have the same specifications as the converter 32, and configured to spray the foam-like anti-scattering agent from those spray nozzles.

(4) A camera and lighting equipment can be attached to the removal device 25, and asbestos can be removed while checking the status of asbestos removal. A device for wiping off dirt from the camera lens can also be attached, and the lens can be wiped off periodically or when dirt is confirmed, to prevent interference with photography. A device for wiping off dirt from the light-emitting surface of the lighting equipment can also be attached.

(5) A suction device that sucks the gas inside the asbestos recovery device 51 to the outside can be provided to suck up the asbestos particles floating inside the asbestos recovery device 51. In this case, by providing the above-mentioned HEPA filter in the exhaust pipe of the suction device, it is possible to prevent the sucked asbestos particles from leaking into the atmosphere.
Also, a member may be provided that covers the periphery of the sealing device 57 or the periphery of the valve device 56 and the sealing device 57, and a suction device may be connected to the member. With this configuration, even if asbestos leaks from the sealing device 57 or the valve device 56 when attaching or detaching the collection bag 61 from the sealing device 57, the leaked asbestos can be sucked up, so there is no risk of a person attaching or detaching the collection bag 61 inhaling asbestos and causing damage to their health.

(6) When the weight of asbestos collected in the collection bag 61 reaches a predetermined weight, the operation of the suction device 81 can be temporarily stopped, the coagulant supply device 58 can be operated, the coagulant can be sprayed into the collection bag 61, and the operation of the suction device 81 can be resumed after the spraying of the coagulant has been completed. Also, a spray nozzle 65 for spraying the coagulant can be provided on a predetermined member constituting the valve device 56, and the spray hole of the spray nozzle 65 can be configured to face the inside of the collection bag 61.

REFERENCE SIGNS LIST 1 Asbestos recovery system 10 Chimney 12 Opening 21 High-pressure water supply device 25 Removal device 26 Lid 30 Scattering inhibitor supply device 32 Converter 51 Asbestos recovery device 52 Suction hose 53 Suction hose 54 Hopper 55 First sensor 56 Valve device 57 Sealing device 58 Coagulant supply device 59 Filter 61 Recovery bag 62 Second sensor 64 Control unit 65 Spray nozzle 70 Blocking member 72 Insertion hole 73 First through hole 74 Second through hole 75 First globe 76 Second globe 81 Suction device As Asbestos P Worker

Claims (2)

An asbestos removal method for removing asbestos sprayed onto the inner surface of a chimney, comprising the steps of:
An opening communicating with the inside and the outside of the chimney is formed in the lower part of the chimney,

A scattering inhibitor for suppressing scattering of the asbestos;
A removal device for removing the asbestos by spraying high-pressure water onto the asbestos sprayed on the inner surface of the chimney;
A suction and recovery device that sucks and recovers the asbestos removed from the inner surface of the chimney;
a blocking member having an insertion hole through which a suction hose connected to the suction recovery device can be inserted and capable of blocking the opening;

a filling step of filling the inside of the chimney with the scattering suppressant in a foam form;
a removal process in which, after the filling process, a removal device that sprays the high-pressure water is moved inside the chimney while spraying the high-pressure water to remove the asbestos, and the asbestos that has been removed and accumulated in the lower part of the chimney is sucked and collected by the suction collection device using the suction hose inserted into the insertion hole of the blocking member that blocks the opening ,

In addition,
The blocking member is
A vent communicating with the inside and outside of the chimney;
and a filter provided in the ventilation hole for filtering out asbestos particles removed by the removal process . The removing step includes:
2. The asbestos removal method according to claim 1, characterized in that the method is carried out by covering the tip of the chimney.

Images