Processing device and method

Abstract

A laser beam emitted from a laser light source (101) passes, for example, through a fiber collimator (105) by propagating through an optical fiber (111), is formed into a desired beam diameter, thereafter, the beam shape thereof is controlled by an optical element (106), and thereafter, a processing target object (151) is irradiated. The optical element (106) is controlled by a controller (104), and subjects the laser beam to a beam shape and power density control. A lighting device (102) shines light on the dust produced during laser beam irradiation. A camera (103) images a region of the dust which is illuminated by the light. The controller (104) obtains the brightness of the light reflected by the dust and the scattering speed of the dust from the image captured by the camera (103), and controls the laser beam emitted by the laser light source (101).

Description

[Technical field]

[0001] The present invention relates to a method for treating an object containing asbestos, for example by rendering it harmless. [Background technology]

[0002] Asbestos has excellent insulating properties and durability, so it is widely used as an insulating material for buildings, houses, etc. The use of asbestos in domestic buildings began around 1955, and it was widely used as a lightweight fireproof coating material, especially as buildings became taller and more steel-framed during the period of high economic growth from the 1960s onwards.

[0003] While asbestos is useful as a building material, it is also known to be a health hazard as it can damage lung tissue when inhaled, leading to serious diseases such as asbestosis, mesothelioma and lung cancer. In this context, asbestos has been found to be dispersed due to the deterioration of sprayed asbestos used as fireproof coating for steel frames, measures to remove and contain the asbestos have been implemented.

[0004] Initially, the removal of sprayed asbestos was carried out by scraping, cutting or crushing after isolating and curing the removal area and work site. After that, with the amendment of the Air Pollution Control Act in 1996, work standards were established for the demolition, remodeling and repair of buildings as "work involving specific dust emissions, etc.", and various methods were considered and developed to improve the efficiency of asbestos removal work during the demolition of asbestos-containing buildings.

[0005] Representative methods for removing sprayed asbestos as mentioned above include the scraping method, the disc grinder method, and the water jet method. The scraping method is a method in which workers use hand tools (surface scrapers, scrapers, wire brushes, etc.) to scrape off the exterior wall finishing coating material. For this reason, the scraping method can reliably remove asbestos even in small areas such as under the eaves or in uneven areas, and produces relatively less dust compared to other methods. However, the scraping method, which is done manually, has low work efficiency.

[0006] In contrast, the disc grinder method, which uses a disc attached to a high-speed rotating power tool to grind and remove the exterior wall finish coating, is highly efficient. However, the disc grinder method generates a large amount of dust. One method to suppress this dust and remove the sprayed asbestos is the water jet method, which uses high-pressure water to remove the exterior wall finish coating. The water jet method can suppress dust generation and is highly efficient, but it is not suitable for small areas or areas with uneven surfaces, so it is necessary to use another method in such areas.

[0007] According to Non-Patent Document 1, the melting point of chrysotile, a type of asbestos, is over 1500°C, so the above-mentioned removal methods cannot render asbestos harmless. For this reason, it is necessary to collect the removed coating material and treat it as asbestos-containing waste.

[0008] The methods of disposal of asbestos-containing waste published by the Ministry of the Environment include recycling or landfilling after melting or detoxifying, and double-packing or treatment to prevent scattering before landfilling. As there is a possibility that asbestos may scatter in the air when double-packing or treatment to prevent scattering is used for landfilling, detoxification is recommended. Methods of detoxifying asbestos include heating to high temperatures to melt the asbestos, but this requires a huge amount of energy and is difficult to handle with the increasing number of demolition cases. [Prior art documents] [Non-patent literature]

[0009] [Non-Patent Document 1] Kasai Kenichi et al., "Comprehensive Manual for Preventing Asbestos Exposure and Asbestos Dispersal / Leakage During the Demolition of Buildings, etc., Chapter 1, Basic Knowledge about Asbestos, Table 1.1.2 Chemical and Physical Properties of Various Types of Asbestos," Chemical Substances Control Division, Occupational Safety and Health Department, Labor Standards Bureau, Ministry of Health, Labor and Welfare, Air Environment Division, Water and Air Environment Bureau, Ministry of the Environment, March 2021. Summary of the Invention [Problem to be solved by the invention]

[0010] To solve the above problems, a method has been considered in which a laser is irradiated onto the target object, such as sprayed asbestos or other coating materials that contain asbestos, to render the asbestos harmless. However, with this method, the asbestos contained in the target object absorbs part of the energy of the laser light, generates heat, melts, and is rendered harmless. During this process, bumping and other problems occur, causing the scattering of un-neutralized asbestos.

[0011] The present invention has been made to solve the above-mentioned problems, and aims to make it possible to prevent the scattering of undetoxified asbestos when detoxifying asbestos by laser irradiation. [Means for solving the problem]

[0012] The processing apparatus of the present invention comprises a laser light source which irradiates a processing object with laser light, an illuminator which illuminates dust generated by the irradiation of the laser light, a camera which images the area of ​​dust which is illuminated, and a controller which determines the brightness of light reflected from the dust from the image captured by the camera, determines the dispersion speed of the dust from the image captured by the camera, and controls the laser light irradiated by the laser light source based on the brightness and dispersion speed.

[0013] The processing method of the present invention includes a first step of irradiating a processing object with laser light, a second step of illuminating the dust generated by the irradiation of the laser light and imaging the area of ​​the dust that is illuminated, a third step of determining the brightness of the light reflected from the dust from the image captured in the second step, a fourth step of determining the dust dispersion speed from the image captured in the second step, and a fifth step of controlling the laser light based on the brightness and the dispersion speed. Effect of the Invention

[0014] As described above, according to the present invention, the brightness of light reflected from the dust and the dust scattering speed are obtained from the image of the dust captured by the camera, and the laser light is controlled, so that when asbestos is rendered harmless by laser irradiation, the scattering of undetoxified asbestos can be suppressed. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a configuration diagram showing the configuration of a processing device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a flow chart illustrating a processing method according to an embodiment of the present invention. [Diagram 3] FIG. 3 is a characteristic diagram showing a processing result in the first embodiment. [Figure 4] FIG. 4 is a characteristic diagram showing a processing result in the first embodiment. [Figure 5A] FIG. 5A is a microscopic image showing the results of observation of asbestos (chrysotile) by an electron microscope before laser irradiation. [Figure 5B] FIG. 5B is a characteristic diagram showing the elemental analysis results of asbestos (chrysotile) before laser irradiation. [Figure 5C] FIG. 5C is a microscopic image showing the results of observation of asbestos (chrysotile) after laser irradiation using an electron microscope. [Figure 5D] FIG. 5D is a characteristic diagram showing the elemental analysis results of asbestos (chrysotile) after laser irradiation. [Figure 6] FIG. 6 is a characteristic diagram showing a processing result in the second embodiment. [Figure 7] FIG. 7 is a characteristic diagram showing a processing result in the second embodiment. [Figure 8] FIG. 8 is a characteristic diagram showing a processing result in the third embodiment. [Figure 9] FIG. 9 is a characteristic diagram showing a processing result in the third embodiment. [Figure 10] FIG. 10 is a block diagram showing the hardware configuration of a controller of a processing device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] A processing device according to an embodiment of the present invention will now be described with reference to Fig. 1. This processing device includes a laser light source 101, an illuminator 102, a camera 103, and a controller 104.

[0017] The laser light source 101 irradiates a laser beam onto a processing object 151. The processing object 151 is, for example, an object that includes an asbestos-containing coating material. The laser light source 101 may be any light source capable of generating a laser beam with a wavelength capable of forming a desired intensity distribution, and it is preferable that the output is variable in order to suppress scattering of dust due to bumping when the processing object 151 is irradiated with the laser beam. In addition, the processing object 151 can be cut by the laser beam irradiated from the laser light source 101.

[0018] The laser light emitted from the laser light source 101 propagates through the optical fiber 111 and passes through the fiber collimator 105, for example, and is shaped into a desired beam diameter. The beam shape is then controlled by the optical element 106, and the object to be processed 151 is irradiated with the laser light. For example, the beam shape of the laser light can be controlled to a Bessel beam. The optical element 106 is controlled by the controller 104 via the element controller 107, and controls the power density and beam shape of the laser light, and controls the beam shape of a lens, a diffractive optical element, etc. to shape a desired spatial intensity distribution. The laser light that has passed through the fiber collimator 105 is transmitted through or reflected by the optical element 106, and is shaped into a desired beam diameter.

[0019] The optical element 106 that controls the spatial intensity distribution of the laser light can be composed of a fixed focal length lens or a diffractive optical element. In order to control the power density of the laser light, for example, if the optical element 106 is a fixed focal length lens, the distance between the processing object 151 and the lens can be set so as not to match the focal length of the fixed focal length lens. In order to control the power density of the laser light, if the optical element 106 is a diffractive optical element, the optical element can be designed to form a two-dimensional light intensity distribution of the laser light, such as a point, a straight line, or a concentric circle, on the processing object 151, or to form the laser light into a beam shape, such as a Bessel beam having a uniform beam diameter in the direction of the optical axis 121.

[0020] The illuminator 102 illuminates the dust generated by the irradiation of the laser light. The camera 103 captures an image of the dust area on which the light is applied. The controller 104 first obtains the brightness of the light reflected by the dust from the image captured by the camera 103. The controller 104 also obtains the scattering speed of the dust from the image captured by the camera 103. The controller 104 also controls the laser light emitted by the laser light source 101 based on the obtained brightness and scattering speed. The controller 104 controls the laser light so that the brightness and scattering speed are equal to or less than the set specified values. The controller 104 controls the power density and beam shape of the laser light.

[0021] Next, a processing method according to an embodiment of the present invention will be described with reference to Fig. 2. First, in a first step S101, a laser light source 101 irradiates a processing target 151 with laser light. Next, in a second step S102, an illuminator 102 illuminates dust generated by the irradiation of the laser light, and a camera 103 captures an image of the illuminated area of ​​the dust.

[0022] Next, in a third step S103, the controller 104 obtains the luminance of the light reflected by the dust from the image captured in the second step S102. Also, in a fourth step S104, the controller 104 obtains the dust scattering speed from the image captured in the second step S102. Next, in a fifth step S105, the controller 104 controls the laser light irradiated from the laser light source 101 based on the luminance and scattering speed. In the fifth step S105, the controller 104 controls the laser light so that the luminance and scattering speed are equal to or less than the set specified values. For example, in the fifth step S105, the controller 104 controls the power density and beam shape of the laser light. For example, the beam shape of the laser light is controlled to be a Bessel beam.

[0023] Here, the amount of dust generated by laser irradiation is proportional to the brightness of the reflected light calculated by the controller 104. In addition, the average scattering speed of the dust v average For example, in a captured image (video), the velocity v of dust particles in each of the sections (m, n) divided into 1, 2, 3, m, M in the vertical direction and 1, 2, 3, n, N in the horizontal direction is nm is defined as the average value of the images as follows, where i is the number of captured images.

[0024]

number

[0025] In order to reduce the effect of airflow on the dust scattering speed, the standard deviation can be reduced by calculating the brightness of reflected light and the average dust scattering speed for dust particles that are present in a limited range near the laser irradiated portion in each captured image. For example, by setting an area 152 of 5 mm x 5 mm x 5 mm as the average scattering speed calculation range and focusing on dust particles that are present within the range, the standard deviation of the average dust scattering speed can be reduced.

[0026] Next, a more detailed explanation will be given using an example.

[0027] [Example 1] First, Example 1 will be described. In Example 1, the laser light source 101 emits (outputs) a pulsed laser beam with an average output of 100 W. The peak value of the pulsed laser beam output from the laser light source 101 was 15 kW. The optical element 106 is composed of a single focus lens. The processing object 151 is a concrete piece coated with a coating material containing asbestos (chrysotile).

[0028] The beam diameter of the pulsed laser light was set to 50 μm, and the optical path between the processing object 151 and the optical element 106 was illuminated (illumination light was applied) with illumination light from the illuminator 102, the laser light focused by the optical element 106 was applied to the processing object 151, and the light reflected from the generated dust was captured by the camera 103 according to the flow of Fig. 2. The controller 104 also calculated the brightness of the reflected light and the average scattering speed of the dust, and while monitoring in real time, the optical element 106 was moved parallel to the optical axis 121 so as to reduce the amount of dust generated and the average scattering speed. The results when the beam diameter of the pulsed laser light was set to 140 μm on the processing object 151 are shown in Figs. 3 and 4.

[0029] Compared to when the pulsed laser beam diameter was 50μm, expanding the beam diameter to 140μm and reducing the power density by approximately 90% reduced the amount of dust generated by roughly 50%. In addition, expanding the beam diameter reduced the average dust scattering speed to 6mm / sec, suppressing dust scattering.

[0030] Furthermore, as shown in Figures 5A, 5B, 5C, and 5D, the elemental analysis results of the asbestos before laser irradiation and the asbestos before laser irradiation and the spherical substance observed after laser irradiation are generally consistent, indicating that the spherical substance observed after laser irradiation is melted asbestos before laser irradiation.

[0031] From the above results, in this embodiment, it is possible to render asbestos harmless while suppressing the amount of dust generated and the average scattering speed of the dust.

[0032] [Example 2] Next, a description will be given of Example 2. In Example 2, the laser light source 101 outputs a continuous wave (CW) laser with an output of 50 W. The optical element 106 is composed of a single focus lens. The processing object 151 is a concrete piece coated with a coating material containing asbestos (chrysotile).

[0033] The beam diameter of the CW laser light was set to 50 μm, the optical path between the processing object 151 and the optical element 106 was illuminated (illumination light was applied) with illumination light from the illuminator 102, the CW laser light focused by the optical element 106 was applied to the processing object 151, and the light reflected from the generated dust was captured by the camera 103 according to the flow of Fig. 2. In addition, the controller 104 calculated the brightness of the reflected light and the average scattering speed of the dust, and while monitoring in real time, the optical element 106 was moved parallel to the optical axis 121 so as to reduce the amount of dust generated and the average scattering speed. The results when the beam diameter of the CW laser light was set to 140 μm on the processing object 151 are shown in Figs. 6 and 7.

[0034] Compared to the condition where the beam diameter of the CW laser light is 50 μm, by setting the beam diameter to 140 μm and reducing the power density by about 90%, the amount of dust generated immediately after the laser irradiation and the average scattering speed were reduced, and the scattering of dust could be suppressed. The minimum value of the average scattering speed of the dust measured at this time was 0 mm / sec. Furthermore, compared to Example 1, by reducing the output of the CW laser light, the amount of dust generated and the average scattering speed were reduced, and the scattering of dust could be suppressed. From the above results, in this example, the amount of dust generated and the average scattering speed of the dust can be suppressed while detoxifying asbestos.

[0035] [Example 3] Next, a third embodiment will be described. In the third embodiment, the laser light source 101 outputs a CW laser with an output of 50 W. The optical element 106 is composed of a diffractive optical element. The diffractive optical element forms the CW laser light into a rectangular beam shape of 5 mm×0.2 mm with uniform power density as an initial condition. The processing object 151 is a piece of concrete coated with a coating material containing asbestos (chrysotile).

[0036] The light path between the object to be treated 151 and the optical element 106 was illuminated (illumination light was irradiated) with illumination light from the illuminator 102, the object to be treated 151 was irradiated with the CW laser light shaped into a beam by the optical element 106, and the light reflected by the generated dust was captured by the camera 103 according to the flow of FIG. 2. The controller 104 also calculated the brightness of the reflected light and the average scattering speed of the dust, and while monitoring in real time, the beam shape of the CW laser light was controlled by the diffractive optical element to a Bessel beam having a uniform intensity distribution on the optical axis 121 so that the amount of dust generated and the average scattering speed were reduced. The results of changing the beam shape to a Bessel beam are shown in FIG. 8 and FIG. 9. By changing the beam shape of the CW laser light to a Bessel beam, the amount of dust generated and the average scattering speed were reduced, and the scattering of dust was suppressed.

[0037] [Example 4] Next, a fourth embodiment will be described. In the fourth embodiment, the laser light source 101 outputs a CW laser with an output of 50 W. The optical element 106 is composed of a single-focus lens. The processing object 151 is a concrete piece coated with a coating material containing asbestos (chrysotile).

[0038] The beam diameter of the CW laser light was set to 50 μm, and the light path between the processing object 151 and the optical element 106 was illuminated (illumination light was irradiated) with illumination light from the illuminator 102, and the CW laser light focused by the optical element 106 was irradiated onto the processing object 151, cutting the processing object 151. In addition, according to the flow of Fig. 2, the reflected light reflected by the generated dust was captured by the camera 103. The controller 104 calculated the brightness of the reflected light and the average scattering speed of the dust, and while monitoring in real time, the optical element 106 was moved parallel to the optical axis 121 so as to reduce the amount of dust generated and the average scattering speed.

[0039] The cut surface of the object to be treated 151 is melted, and the asbestos in the object to be treated 151 is rendered harmless. Since the cut surface solidifies after melting, the amount of dust generated and the speed at which the dust scatters are reduced, and the scattering of dust can be suppressed, compared to when cutting with power tools.

[0040] [Example 5] Next, a fifth embodiment will be described. In the fifth embodiment, the laser light source 101 outputs a CW laser with an output of 50 W. The optical element 106 is composed of a diffractive optical element. The diffractive optical element shapes the CW laser light into a rectangular beam of 5 mm×0.2 mm with uniform power density as an initial condition. The processing object 151 is a piece of concrete coated with a coating material containing asbestos (chrysotile).

[0041] The optical path between the object to be treated 151 and the optical element 106 was illuminated (illumination light was applied) with illumination light from the illuminator 102, and the object to be treated 151 was irradiated with the CW laser light whose beam shape was shaped by the optical element 106, thereby cutting the object to be treated 151. In addition, according to the flow of Fig. 2, the reflected light reflected by the generated dust was captured by the camera 103. In addition, the controller 104 calculated the brightness of the reflected light and the average scattering speed of the dust, and while monitoring in real time, the beam shape of the CW laser light was controlled by the diffractive optical element to a Bessel beam having a uniform intensity distribution on the optical axis 121 so as to reduce the amount of dust generated and the average scattering speed.

[0042] The cut surface of the object to be treated 151 is melted, and the asbestos in the object to be treated 151 is rendered harmless. Since the cut surface solidifies after melting, the amount of dust generated and the speed at which the dust scatters are reduced, and the scattering of dust can be suppressed, compared to when cutting with power tools.

[0043] [Example 6] Next, a sixth embodiment will be described. In the sixth embodiment, the laser light source 101 outputs a CW laser with an output of 50 W. The optical element 106 is composed of a diffractive optical element. The diffractive optical element causes the CW laser light to have a rectangular beam shape of 5 mm×0.2 mm with uniform power density under the initial condition. The processing object 151 is a piece of concrete coated with a coating material containing asbestos (chrysotile).

[0044] The optical path between the object to be treated 151 and the optical element 106 was illuminated (illumination light was applied) with illumination light from the illuminator 102, and the object to be treated 151 was irradiated with the CW laser light whose beam shape was shaped by the optical element 106, thereby cutting the object to be treated 151. In addition, according to the flow of Fig. 2, the reflected light reflected by the generated dust was captured by the camera 103. In addition, the controller 104 calculated the brightness of the reflected light and the average scattering speed of the dust, and while monitoring in real time, the beam shape of the CW laser light was controlled by the diffractive optical element to a beam having a concentric power density distribution so as to reduce the amount of dust generated and the average scattering speed.

[0045] The cut surface of the object to be treated 151 is melted, and the asbestos in the object to be treated 151 is rendered harmless. Since the cut surface solidifies after melting, the amount of dust generated and the speed at which the dust scatters are reduced, and the scattering of dust can be suppressed, compared to when cutting with power tools.

[0046] As shown in FIG. 10, the controller according to the above-mentioned embodiment may be a computer device including a CPU (Central Processing Unit) 301, a main storage device 302, an external storage device 303, a network connection device 304, etc., and the above-mentioned functions (third, fourth, and fifth steps of the processing method) may be realized by the CPU 301 operating (executing) a program deployed in the main storage device 302. The above-mentioned program is a program for causing a computer to execute the third, fourth, and fifth steps of the processing method shown in the above-mentioned embodiment. The network connection device 304 is connected to a network 305. Also, each function may be distributed to a plurality of computer devices.

[0047] As described above, according to the present invention, the brightness of light reflected from the dust and the dust scattering speed are obtained from the image of the dust captured by the camera, and the laser light is controlled, so that when asbestos is rendered harmless by laser irradiation, the scattering of undetoxified asbestos can be suppressed.

[0048] It should be noted that the present invention is not limited to the above-described embodiments, and it is apparent that many modifications and combinations can be made by a person having ordinary knowledge in the art within the technical concept of the present invention. [Explanation of symbols]

[0049] 101...laser light source, 102...illuminator, 103...camera, 104...controller, 105...fiber collimator, 106...optical element, 107...element controller, 111...optical fiber, 121...optical axis, 151...processing object, 152...area.

Claims

1. A laser light source that irradiates a processing object with laser light; an illuminator for illuminating dust generated by irradiation with the laser light; a camera for capturing an image of the dust area that is illuminated; a controller that calculates a luminance of light reflected from the dust from an image captured by the camera, calculates a scattering speed of the dust from the image captured by the camera, and controls the laser light irradiated by the laser light source based on the luminance and the scattering speed; A processing device comprising:

2. 2. The processing apparatus according to claim 1, The processing device, wherein the controller controls the laser light so that the brightness and the scattering speed are equal to or less than preset specified values.

3. 3. The processing apparatus according to claim 1, The processing apparatus, wherein the controller controls a power density and a beam shape of the laser light.

4. 4. The processing apparatus according to claim 3, The processing apparatus, wherein the controller controls the beam shape of the laser light to be a Bessel beam.

5. 5. The processing apparatus according to claim 3, A processing device comprising a diffractive optical element for controlling the power density and beam shape of the laser light.

6. The processing apparatus according to any one of claims 1 to 5, The processing apparatus, wherein the laser light source irradiates the object with the laser light to cut the object.

7. A first step of irradiating a processing object with laser light; A second step of illuminating the dust generated by the irradiation of the laser light and capturing an image of the dust area on which the light is irradiated; A third step of determining the luminance of light reflected by the powder from the image captured in the second step; A fourth step of calculating a scattering velocity of the dust from the image captured in the second step; a fifth step of controlling the laser light based on the brightness and the scattering speed; A processing method comprising:

8. 8. The method of claim 7, further comprising: The fifth step includes a step of controlling the laser light so that the brightness and the scattering speed are equal to or less than preset specified values.

9. 9. The method according to claim 7 or 8, The processing method according to claim 5, wherein the fifth step includes a step of controlling a power density and a beam shape of the laser light.

10. 10. The method of claim 9, further comprising: The processing method according to claim 5, wherein the fifth step includes a step of controlling the beam shape of the laser light to a Bessel beam.

Images