JP2023035337A - Decontamination method, decontamination device and decontamination system - Google Patents

Abstract

To provide a decontamination technique which can easily avoid the occurrence of a vitrification phenomenon without requiring continuous temperature measurement of a front surface part during the decontamination work and can easily avoid the occurrence of secondary contamination following removal of a contamination layer when removing a contamination layer by peeling and destroying the contamination layer of the front surface part of an inorganic structure like a concrete structure with irradiation of a laser beam.SOLUTION: A laser beam LB is irradiated downward by a laser gun 21 and simultaneously ultrasonic mists UM are sprayed obliquely downward by a spray nozzle 31 to the same position as the irradiation position. The ultrasonic mists UM cool a front surface part S by the evaporation heat generated in the time of evaporation when reaching the front surface part S, enter independent air bubbles CC and mixed air bubbles MC of a contamination layer before the occurrence of a vitrification phenomenon without melting of the front surface part S or even when a portion thereof melts, suddenly expand in the air bubbles CC, MC to generate a phreatic explosion-like phenomenon to peel and destroy the contamination layer, and discharge the contamination layer as contamination pieces PP.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a decontamination method, a decontamination apparatus, and a decontamination system for removing a contaminated layer of an inorganic structure such as a concrete structure by irradiation with a laser beam.

Laser processing technology, which uses a laser beam to rapidly heat the surface of a workpiece, is also used in the field of material removal such as cutting, drilling, and surface layer removal. Among them, for example, when a concrete structure is used as a workpiece (material removal target), inorganic solid particles such as silica (silicon dioxide) are the main component of gravel and sand that serve as aggregates in the concrete structure. When silica (inorganic solid particles), etc. (inorganic solid particles) that have been heated and melted (melted) by laser beam irradiation are rapidly cooled, they sometimes become highly viscous and amorphous glass due to glass transition ( vitrification phenomenon). Even if this glassy portion is re-melted by being re-irradiated with a laser beam of a higher output, there is a risk that the re-melted portion or its surroundings will vitrify again. must be removed by mechanical means.

Patent Document 1 discloses a decontamination technique for removing a radioactively contaminated layer on a concrete surface contaminated with radioactivity by irradiating a laser beam, comprising a laser irradiation step of melting the radioactively contaminated layer by irradiating a laser beam; A high-pressure gas injection process in which high-pressure gas is injected into the molten contamination layer to cool it and pulverize it into contaminant powder, and a contaminant powder recovery process in which the contaminant powder is recovered are sequentially carried out to remove the radioactive contamination layer on the concrete surface. A decontamination (surface layer removal) technique for removal and recovery is disclosed.

According to the decontamination technique of Patent Literature 1, it is easy to avoid secondary contamination by collecting contaminant powder together with the injection gas. However, if the injection speed of high-pressure gas is increased in order to promote the generation and recovery of contaminant powder, the cooling speed of the molten contaminant layer will be increased, and vitrification will easily occur due to rapid cooling. Therefore, in Patent Document 1, rapid cooling of the molten contaminated layer by injection of high pressure gas is performed by setting a predetermined time difference between the laser irradiation process and the high pressure gas injection process to relax the cooling timing of the molten contaminated layer. Therefore, it is necessary to devise a method to avoid the vitrification phenomenon.

On the other hand, Patent Document 2 discloses a removal technique for cutting or crushing a concrete structure by irradiating it with a laser beam, in which a cooling gas or cooling liquid is jetted, and the surface temperature of the concrete becomes below the melting point due to the irradiation of the laser beam. As such, removal (cutting or shredding) techniques are disclosed that control the power of the laser beam and the like.

According to the removal technique of Patent Document 2, the surface temperature is controlled below the melting point by the irradiation of the laser beam, the concrete does not melt, and the vitrification phenomenon does not occur. No consideration is required for rapid cooling of the layer. However, in order to control the surface temperature of concrete below the melting point, as described in Patent Document 2, a radiation thermometer is installed, and the controller analyzes the temperature measurement data and controls the output of the laser beam. You need the ability to run all the time. Therefore, as in Patent Document 2, even if it can be executed without delay in the field of cutting (or crushing) removal that finishes the entire thickness of a concrete structure in one or several strokes, the surface layer is gradually removed many times. In the field of surface layer removal where the surface temperature distribution and the like are constantly changing due to removal over a long period of time, there is a risk that data analysis will take time and execution of output control will be delayed.

JP-A-2001-116892 Japanese Patent No. 4709599

The problem of the present invention is that when a contaminated layer on the surface of an inorganic structure such as a concrete structure is peeled off and destroyed by irradiation with a laser beam, the temperature of the surface remains constant during the decontamination work. Decontamination technology (decontamination method, decontamination equipment, and decontamination system) that can easily avoid the occurrence of vitrification without requiring measurement and easily avoid the occurrence of secondary contamination accompanying the removal of the contaminated layer. to provide.

Means for solving the problem and effects of the invention

In order to solve the above problems, the decontamination method of the present invention includes:
A method for decontaminating an inorganic structure containing inorganic solid particles, containing a large number of air bubbles, and having a contaminated layer at least on the surface thereof contaminated with a contaminant,
In a closed negative pressure space surrounding the surface portion, the surface portion is irradiated with a laser beam, and at the same time, atomized or atomized liquid is sprayed to the same location as the laser beam irradiation position to peel off the contaminated layer. - Characterized by destroying and removing.

Further, in order to solve the above problems, a representative decontamination method of the present invention includes:
A method for decontaminating a concrete structure containing inorganic solid particles as aggregate, containing a large number of fine closed cells, and forming a contaminated layer in which at least the surface portion is contaminated with a contaminant,
In a closed negative pressure space surrounding the surface portion, the surface portion is irradiated with a laser beam, and at the same time, atomized or atomized liquid is sprayed to the same location as the laser beam irradiation position to peel off the contaminated layer. - Characterized by destroying and removing.

In this way, the atomized or atomized liquid (for example, water) is sprayed simultaneously with the irradiation of the laser beam and at the same place as the irradiation position, and when the atomized or atomized liquid reaches the surface, it evaporates. Occasionally generated heat of vaporization cools the surface and suppresses melting, while expansion due to rapid heating exfoliates and destroys the contaminated layer. Therefore, the occurrence of vitrification can be easily avoided without constantly monitoring the surface temperature and controlling the laser beam output during the decontamination work. In addition, since the atomized or atomized liquid is vaporized and recovered together with the peeled/destroyed pieces of contamination, the occurrence of secondary contamination can be easily avoided.

In the present invention, "pollutants" are toxic substances, radioactive substances, bacteria, etc., which may pollute the environment such as air, water, soil, etc., and may impair the health of decontamination workers and surrounding residents. Harmful substances in general. For example, in tunnels such as highways and subways, toxic substances such as black soot, NOx dust, SOx dust, PM dust, and dioxin are mainly present. Also, in nuclear power plants, nuclear fuel reprocessing plants and their surrounding areas, it is mainly radioactive materials such as cesium and plutonium.

Here, "the same place as the irradiation position" in "injecting the atomized or atomized liquid at the same place as the irradiation position of the laser beam" means "the focal position of the beam" in the stationary laser beam. and when it moves, it is represented by the "trajectory of movement of the beam focus". In the case of a laser beam rotating on a circular orbit for output amplification, it means "within the beam rotation diameter (e.g. 50 mm)", and in the case of a laser beam moving while rotating, it means "beam movement width (e.g. 50 mm). ) means “within”.

Furthermore, water is usually used as the above-mentioned "liquid", and general tap water, well water, spring water, etc. may be used instead of pure water or distilled water. As the "atomized or atomized liquid", "ultrasonic atomized water", that is, "ultrasonic mist" is recommended as described later.

Regarding peeling and destruction of the contaminated layer, specifically,
The liquid sprayed toward the surface cools the surface heated by the laser beam (due to the heat of vaporization generated during evaporation) to suppress melting,
The liquid that has entered the bubbles of the contamination layer is rapidly heated by the laser beam, rapidly expands inside the bubbles (by generating a small-scale steam explosion phenomenon), and peels off and destroys the contamination layer.

In this way, the atomized or atomized liquid that is sprayed toward the surface cools the surface due to the heat of vaporization, and the surface does not melt, or even if it partially melts, the glass melts. It can enter the bubbles of the contaminated layer before the decomposition phenomenon occurs, expand rapidly in the bubbles, generate a steam explosion phenomenon, peel and destroy the contaminated layer, and can be released as contaminated fragments.

Furthermore, the irradiation of the laser beam and the injection of the liquid described above are performed continuously or intermittently on the same part of the contamination layer in synchronism with each other (breaking the contamination layer into fine contamination pieces like sparklers). Remove.

As a result, the peeling/breaking of the contaminated layer and the removal of the contaminated pieces are continuously performed without interruption. Note that intermittent laser beam irradiation and liquid injection include a case of pulsed operation and a case of repeated reciprocating motion. As the laser beam, either a CW laser that is continuously irradiated or a pulsed laser that is intermittently irradiated may be used.

By the way, "concrete structures" include concrete pavements, concrete retaining walls, concrete buildings, concrete tunnels (tunnels), and the like. "Concrete" includes cement concrete, asphalt concrete, resin concrete and the like.

Furthermore, the "inorganic structure" includes, for example, the following in addition to the above-mentioned "concrete structure".
- Mortar walls, plaster walls, clay walls, brick walls, tile walls;
・Concrete block pavement, asphalt block pavement, brick pavement, tile pavement.

In the case of a reinforced concrete structure or an earthen wall with a bamboo frame (Take Komai), the decontamination method of the present invention is applied to the concrete portion excluding the reinforcing bars and the painted wall portion excluding the bamboo frame (Take Komai).

Furthermore, in order to solve the above problems, the decontamination device of the present invention is
A decontamination apparatus for an inorganic structure containing inorganic solid particles, containing a large number of air bubbles, and forming a contaminated layer at least on the surface thereof contaminated with a contaminant,
a decontamination chamber to which a suction mechanism is connected and which forms a closed negative pressure space surrounding the surface portion;
a laser irradiation mechanism for irradiating the surface portion with a laser beam;
a liquid injection mechanism for injecting an atomized or atomized liquid onto the surface,
In the decontamination chamber, the laser irradiation mechanism irradiates the laser beam to the surface portion, and at the same time, the liquid injection mechanism sprays the atomized or atomized liquid to the same place as the laser beam irradiation position, so that the liquid is peeled off and destroyed. The suction mechanism sucks and removes the contaminated layer.

Further, in order to solve the above problems, a representative decontamination device of the present invention includes:
A decontamination apparatus for a concrete structure that contains inorganic solid particles as aggregate, contains a large number of fine closed cells, and forms a contaminated layer in which at least the surface portion is contaminated with a contaminant,
a decontamination chamber to which a suction mechanism is connected and which forms a closed negative pressure space surrounding the surface portion;
a laser irradiation mechanism for irradiating the surface portion with a laser beam;
a liquid injection mechanism for injecting an atomized or atomized liquid onto the surface,
In the decontamination chamber, the laser irradiation mechanism irradiates the laser beam to the surface portion, and at the same time, the liquid injection mechanism sprays the atomized or atomized liquid to the same place as the laser beam irradiation position, so that the liquid is peeled off and destroyed. The suction mechanism sucks and removes the contaminated layer.

In this way, at the same time as the irradiation of the laser beam by the laser irradiation mechanism and at the same place as the irradiation position, the atomized or atomized liquid (for example, water) is injected by the liquid injection mechanism, and the atomized or atomized liquid When it reaches the surface, the heat of vaporization generated during evaporation cools the surface to suppress melting, and the expansion due to rapid heating exfoliates and destroys the contaminant layer. Therefore, the occurrence of vitrification can be easily avoided without constantly monitoring the surface temperature and controlling the laser beam output during the decontamination work. In addition, since the atomized or atomized liquid is vaporized and recovered together with the peeled/destroyed pieces of contamination, the occurrence of secondary contamination can be easily avoided.

An atomization mechanism is recommended as the liquid injection mechanism. Known atomization mechanisms include a suction atomization system that utilizes the suction action of a negative pressure generator and a driven atomization system that is driven by a drive source other than the negative pressure generator. The former method includes a mist spray method in which an air stream is sprayed onto the sucked up liquid (water) using capillary action, and a speed increasing mechanism method in which a venturi or diffuser is attached. On the other hand, the latter system includes an ejector system that accelerates by a pressure pump or the like, a centrifugal system that accelerates by high-speed rotation, an ultrasonic system that vibrates with ultrasonic waves, and the like.

The suction mechanism has a negative pressure pump (suction fan) for sucking the contaminated air generated in the decontamination room under negative pressure, and a dust collector that is arranged in the suction flow path of the negative pressure pump and has an air filter. ing. This air filter consists of a main filter positioned downstream of the suction flow path and composed of a high-performance air filter such as a HEPA filter or ULPA filter, and a coarse dust air filter positioned upstream of the main filter in the suction flow path. and a pre-filter composed of filters.

The HEPA filter (high efficiency particulate air filter) has a particle collection rate of 99.97% or more for particles with a particle size of 0.3 μm at the rated flow rate, and the ULPA filter (ultra low penetration air filter) at the rated flow rate. It has a particle collection rate of 99.9995% or more for particles with a particle size of 0.15 μm. In particular, a filter with a particle collection rate of 99.9999% or higher is sometimes called an ultra-ULPA filter. Also, coarse particle air filters are primarily used to remove particles larger than 5 μm in size. Furthermore, between the main filter and the pre-filter, for example, a medium efficiency particulate air filter (that is, an air filter with a medium particle collection efficiency for particles with a particle size of less than 5 μm) is configured. You may add an intermediate filter that These air filters comply with JIS Z8122 "Contamination Control Terms".

The liquid injection mechanism ejects a mist having a particle size smaller than that of the air bubbles in the contaminated layer by ultrasonic atomization.

Concrete structures are made by hardening aggregates, which occupy most of the volume, with binders such as cement, asphalt, and resin. As aggregates, coarse aggregates of about 5 mm or more, such as gravel and crushed stone, and fine aggregates of less than about 5 mm, such as sand and crushed sand, are used.

In addition, inside the concrete structure, there are relatively large mixed cells (for example, 0.1 mm or more) confined during kneading of the binder and water, and an AE agent added as an admixture ( There are fine closed cells (eg, 0.01-0.1 mm, average 0.05 mm) generated by air-entraining agents.

On the other hand, the particle size of fog (ultrasonic mist) generated by ultrasonic atomization is generally about 0.001 to 0.01 mm (average 0.005 mm). Therefore, the particle size of the ultrasonic mist can be made smaller than the closed cells inherent in the concrete structure.

Independent bubbles and mixed bubbles are opened on the surface destroyed by laser beam irradiation, and the sprayed ultrasonic mist enters these bubbles one after another, is rapidly heated by the laser beam, and expands rapidly within these bubbles. As a result, the contamination layers are peeled off and destroyed one after another due to the occurrence of a small-scale steam explosive phenomenon, and fine contamination fragments are generated. In this way, the use of ultrasonic mist facilitates the peeling and breaking of the contaminated layer and the removal of the contaminated pieces.

The laser irradiation mechanism includes a single lens or a combination lens for irradiating a laser beam, and the lens closest to the surface among these lenses that blows air to the objective lens surface, which is the lens surface facing the surface. A gas injection mechanism is provided for
The gas injection mechanism constantly blows air toward the objective lens surface during operation of the laser irradiation mechanism.

In this way, the gas blown from the gas injection mechanism suppresses the contact (collision) of the contamination pieces peeled and destroyed from the contamination layer on the surface to the objective lens surface of the laser irradiation mechanism. Contributes to longer life.

Air is generally used as the gas blown from the gas injection mechanism. ), nitrogen gas, carbon dioxide gas, etc.) can also be used. Also, part of the gas blown from the gas injection mechanism is introduced into the liquid injection mechanism, and the atomized or atomized liquid (e.g., ultrasonic mist) injected from the liquid injection mechanism is transferred to the blown gas (e.g., air). ).

And, in order to solve the above problems, the decontamination system of the present invention is
A decontamination system for an inorganic structure containing inorganic solid particles, containing a large number of air bubbles, and forming a contaminated layer in which at least a surface portion is contaminated with a contaminant,
a decontamination chamber to which a suction mechanism is connected and which forms a closed negative pressure space surrounding the surface portion;
a laser irradiation mechanism for irradiating the surface portion with a laser beam;
a liquid injection mechanism for injecting an atomized or atomized liquid onto the surface;
a control unit that issues a control signal to the laser irradiation mechanism and the liquid ejection mechanism;
The controller causes the laser irradiation mechanism to irradiate the surface portion with a laser beam in the decontamination chamber, and at the same time, the liquid injection mechanism injects the atomized or atomized liquid to the same place as the irradiation position of the laser beam. A control signal is issued so that the suction mechanism sucks and removes the peeled/destroyed contaminant layer.

Also, in order to solve the above problems, a representative decontamination system of the present invention includes:
A decontamination system for a concrete structure that contains inorganic solid particles as an aggregate, contains a large number of fine closed cells, and forms a contaminated layer in which at least a surface portion is contaminated with a contaminant,
a decontamination chamber to which a suction mechanism is connected and which forms a closed negative pressure space surrounding the surface portion;
a laser irradiation mechanism for irradiating the surface portion with a laser beam;
a liquid injection mechanism for injecting an atomized or atomized liquid onto the surface;
a control unit that issues a control signal to the laser irradiation mechanism and the liquid ejection mechanism;
The controller causes the laser irradiation mechanism to irradiate the surface portion with a laser beam in the decontamination chamber, and at the same time, the liquid injection mechanism injects the atomized or atomized liquid to the same place as the irradiation position of the laser beam. A control signal is issued so that the suction mechanism sucks and removes the peeled/destroyed contaminant layer.

In this way, at the same time as the irradiation of the laser beam by the laser irradiation mechanism and at the same place as the irradiation position, the atomized or atomized liquid (for example, water) is injected by the liquid injection mechanism, and the atomized or atomized liquid When the vapor reaches the surface, the control unit issues a control signal so that the surface is cooled by the heat of vaporization generated at the time of evaporation to suppress melting, and the contaminant layer is peeled off and destroyed by expansion due to rapid heating. Therefore, the occurrence of vitrification can be easily avoided without constantly monitoring the surface temperature and controlling the laser beam output during the decontamination work. In addition, since the atomized or atomized liquid is vaporized and recovered together with the peeled/destroyed pieces of contamination, the occurrence of secondary contamination can be easily avoided.

In addition to mounting or pulling the decontamination chamber, laser irradiation mechanism, liquid injection mechanism and control unit described above, the position of the work area to be decontaminated with respect to the surface can be changed collectively by the control signal emitted from the control unit. and a mobile device (eg, mobile work vehicle or aerial work vehicle).

As a result, in the case of decontamination work in an open work area, the decontamination work can be automated while the work vehicle is automatically driven by the control signal. It is also possible to automate only the decontamination work while the worker drives the work vehicle.

In addition to installing the decontamination chamber, laser irradiation mechanism and liquid injection mechanism described above, a moving device (for example, a mobile work cart with a robot arm) that can collectively change the position with respect to the surface part in the work area to be decontaminated. prepared,
The control unit is arranged at a predetermined position outside the work area,
The moving device changes the positions of the decontamination chamber, the laser irradiation mechanism, and the liquid injection mechanism within the work area according to a control signal issued based on the remote control of the control unit.

As a result, in the case of decontamination work in a closed work area, it is possible to move robot arms and mobile work carts based on control signals while workers are watching from a safe control unit (external control room) outside the work area. Full automation of all decontamination work processes is possible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram schematically showing an example of a decontamination device according to the present invention; Explanatory drawing showing the concept of the decontamination method which concerns on this invention in the principal part of FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram schematically showing a decontamination system for an open road surface work area as a first example of the decontamination system according to the present invention; Process explanatory drawing based on the decontamination system of FIG. FIG. 5 is an explanatory diagram schematically showing a decontamination system for open wall working areas as a second example of the decontamination system according to the present invention. Process explanatory drawing based on the decontamination system of FIG. Explanatory drawing which shows typically the decontamination system for closed work areas in a building as a 3rd example of the decontamination system which concerns on this invention. Process explanatory drawing based on the decontamination system of FIG. Explanatory drawing which shows typically the decontamination system for closed work areas in a tunnel as a fourth example of the decontamination system which concerns on this invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to examples shown in the drawings. FIG. 1 is an explanatory diagram schematically showing an example of a decontamination apparatus according to the present invention. The decontamination apparatus 100 shown in FIG. 1 decontaminates a block-shaped concrete structure CS mounted on a mounting table B. As shown in FIG. The decontamination apparatus 100 includes a decontamination booth 10 (decontamination chamber) to which a suction mechanism 40 is connected to form a closed negative pressure space surrounding the entire concrete structure CS, and a laser beam LB to the concrete structure CS. and a water injection mechanism 30 (liquid injection mechanism) for injecting ultrasonic mist UM onto the surface S (see FIG. 2). Although the mounting table B is fixed on the ground in FIG. 1, it may be movable on the ground in the left-right direction (the direction of the arrow), the direction perpendicular to the paper surface, or the like.

As shown in FIG. 2, the concrete structure CS occupies most of the volume (for example, 70%), and aggregates CA and FA, which are inorganic solid particles, are hardened with binders such as cement, asphalt, and resin. there is Coarse aggregate CA made of gravel and crushed stone and having a size of about 5 mm or more and fine aggregate FA made of sand and crushed sand and having a size of less than about 5 mm constitute the aggregate. Inside the concrete structure CS, there are relatively large mixed cells MC of, for example, 0.1 mm or more, and a large number of fine closed cells CC of, for example, 0.01 to 0.1 mm, average 0.05 mm. The mixed air bubbles MC are air bubbles trapped when the binder and water are kneaded, and the closed air bubbles CC are generated by an AE agent (air entraining agent) added as an admixture. In a concrete structure CS (for example, radioactive waste generated in a nuclear power plant), at least the surface portion S forms a contaminated layer (for example, a radioactive contaminated layer) contaminated with contaminants (for example, radioactive substances).

Returning to FIG. 1, the decontamination booth 10 has a frame 11 that completely covers the concrete structure CS from above like a lid, and a bellows-shaped cover 12 that surrounds the outside of the frame 11, forming a closed space inside. .

The laser irradiation mechanism 20 has a laser gun 21 that downwardly irradiates the laser beam LB toward the surface portion S of the concrete structure CS. The laser gun 21 incorporates a combination lens 22 for irradiating the laser beam LB. Laser gun 21 is connected to laser oscillator 21L via optical fiber 21F.

An air injection nozzle 23 (gas injection mechanism) is attached to the laser irradiation mechanism 20 . The air injection nozzle 23 is provided in the lens (objective lens) closest to the surface portion S of the combined lens 22 along the objective lens surface 22S, which is the lens surface facing the surface portion S of the concrete structure CS. always blows the jet air JA sideways during operation. The air injection nozzle 23 is connected to an air compressor 23C through an air hose 23H.

A laser beam LB is generated by a laser oscillator 21L and emitted downward from a laser gun 21 via an optical fiber 21F. On the other hand, the injection air JA is generated by the air compressor 23C and is blown sideways from the air injection nozzle 23 via the air hose 23H.

The water injection mechanism 30 sprays water (fog) ultrasonically atomized by an ultrasonic atomizer 32 (atomization mechanism) obliquely downward from a spray nozzle 31 as an ultrasonic mist UM. The ultrasonic atomizer 32 is connected to the pump 32P through the hose 23H. The water in the tank 32T is pumped up by the pump 32P, reaches the ultrasonic atomizer 32 through the hose 23H, and is sprayed obliquely downward from the spray nozzle 31 as the ultrasonic mist UM. Also, part of the injection air JA blown from the air injection nozzle 23 is introduced into the spray nozzle 31, and the ultrasonic mist UM sprayed from the spray nozzle 31 is accelerated by the injection air JA.

The particle size of the ultrasonic mist UM is generally about 0.001 to 0.01 mm (average 0.005 mm). Therefore, the particle size of the ultrasonic mist UM can be made smaller than both the closed cells CC and the mixed cells MC existing in the concrete structure CS.

The suction mechanism 40 includes a negative pressure pump 41 (suction fan) for sucking the contaminated air DA generated in the decontamination booth 10 under negative pressure, and an outlet of a flexible hose 42H arranged in the suction channel of the negative pressure pump 41. It has a dust collector 42 connected to the side and containing an air filter 42F. The inlet side (suction side) of the flexible hose 42H opens to the decontamination booth 10. As shown in FIG.

The power supply facility 90 supplies driving power to the laser oscillator 21L, the air compressor 23C, the pump 32P, the ultrasonic atomizer 32 and the negative pressure pump 41, respectively. In addition, in FIG. 1, the dashed-dotted line represents a power supply line.

Next, decontamination of the concrete structure CS by the decontamination device 100 will be described mainly with reference to FIG. Simultaneously with the downward irradiation of the laser beam LB by the laser gun 21 of the laser irradiation mechanism 20 and at the same position as the irradiation position, the spray nozzle 31 of the water injection mechanism 30 jets the ultrasonic mist UM obliquely downward. When the ultrasonic mist UM reaches the surface portion S, the surface portion S is cooled by the heat of vaporization generated during evaporation, and the surface portion S does not melt, or even if it partially melts, vitrification occurs. It enters the closed air bubbles CC and mixed air bubbles MC of the contaminated layer before, expands rapidly in these air bubbles CC and MC, generates a steam explosive phenomenon, peels off and destroys the contaminated layer, and releases as contaminated pieces PP. . The polluted pieces PP become polluted air DA together with jet air JA blown from the air jet nozzle 23, are suctioned by the negative pressure pump 41 under negative pressure, pass through the flexible hose 42H and are captured by the air filter 42F of the dust collector 42 (Fig. 1). reference).

In this way, the occurrence of vitrification can be easily avoided without constantly monitoring the temperature of the surface portion S and controlling the output of the laser beam LB during the decontamination work. Moreover, since the ultrasonic mist UM is vaporized and collected together with the peeled/destroyed contaminated pieces PP, the occurrence of secondary contamination can be easily avoided.

In this embodiment, the laser gun 21 emits the laser beam LB downward and the spray nozzle 31 emits the ultrasonic mist UM obliquely downward, but the orientations may be exchanged. That is, the spray nozzle 31 can be changed to spray downward, and the laser gun 21 can be changed to irradiate obliquely downward. Alternatively, both of them may be changed obliquely downward, and the inclination angles of both may be made different.

FIG. 3 is an explanatory diagram schematically showing a decontamination system for an open road surface work area as a first example of the decontamination system according to the present invention. A decontamination system for an open road surface work area (hereinafter simply referred to as a decontamination system) 1000 shown in FIG. dye. The decontamination system 1000 includes a decontamination booth 10 (decontamination chamber) to which a suction mechanism 40 is connected and which forms a closed negative pressure space surrounding the surface portion S (see FIG. 2) of the concrete pavement CP, and a laser A laser irradiation mechanism 20 that irradiates the surface portion S of the concrete pavement CP with the beam LB, a water injection mechanism 30 (liquid injection mechanism) that injects the ultrasonic mist UM that has been ultrasonically atomized onto the surface portion S, and the laser irradiation mechanism 20. and a controller 200 (control unit) that issues a control signal to the water injection mechanism 30 .

Furthermore, the decontamination system 1000 pulls the decontamination booth 10, the laser irradiation mechanism 20, and the water injection mechanism 30, and is equipped with a controller 200. A work area ( It further includes a mobile work vehicle 300 (moving device) capable of collectively changing the position with respect to the surface portion S on the road surface. The frame 11 of the decontamination booth 10 is connected (towed) to the mobile work vehicle 300 by a connecting bar 310 (connecting mechanism), and the lower end of the frame 11 is equipped with casters 13 for moving on the road surface.

The power supply facility 90 supplies driving power to the laser oscillator 21L, the air compressor 23C, the pump 32P, the ultrasonic atomizer 32, the negative pressure pump 41 and the controller 200, respectively. On the other hand, the controller 200 issues control signals to the laser gun 21, the air injection nozzle 23, the spray nozzle 31, the power supply equipment 90, and the mobile work vehicle 300, respectively. In FIG. 3, dashed lines represent power supply lines, and dashed lines represent control signal lines. The same applies to each of the following figures.

Next, FIG. 4 shows a process explanatory drawing based on the decontamination system of FIG. First, in S1, an ON command is issued to the power supply equipment 90 to start the laser oscillator 21L, the air compressor 23C, the pump 32P, the ultrasonic atomizer 32 and the negative pressure pump 41 to prepare for decontamination. In S2, the laser gun 21, the air injection nozzle 23 and the spray nozzle 31 are synchronously operated to carry out the decontamination work. In S3, an automatic operation command is issued to the mobile work vehicle 300 to move within the open road work area. In S4, as a result of the movement, it is confirmed whether the end of the road surface opening work area has been reached and the decontamination work has been completed. (YES in S4), the process ends.

FIG. 5 is an explanatory diagram schematically showing a decontamination system for an open wall work area as a second example of the decontamination system according to the present invention. A decontamination system for an open wall work area (hereinafter simply referred to as a decontamination system) 2000 shown in FIG. decontaminate. The decontamination system 2000 includes a decontamination booth 10 (decontamination room) to which a suction mechanism 40 is connected and which forms a closed negative pressure space surrounding the surface portion S (see FIG. 2) of the concrete retaining wall CW; A laser irradiation mechanism 20 for irradiating the surface portion S of the concrete retaining wall CW with a laser beam LB, a water injection mechanism 30 (liquid injection mechanism) for injecting ultrasonic mist UM onto the surface portion S, and laser irradiation. and a controller 200 (control unit) that issues control signals to the mechanism 20 and the water injection mechanism 30 .

Furthermore, the decontamination system 2000 holds the decontamination booth 10, the laser irradiation mechanism 20, and the water injection mechanism 30, and is equipped with a controller 200. A work area ( It further includes an aerial work vehicle 400 (moving device) and a lifting device 500 (moving device) capable of collectively changing the position with respect to the surface portion S on the outer wall surface. The frame 11 of the decontamination booth 10 is connected by a connecting link 530 (connecting mechanism) to a winding transmission mechanism 520 (for example, a roller chain driven by a motor 510) of the lifting device 500. It is equipped with casters 13 for

The power supply facility 90 supplies driving power to the laser oscillator 21L, the air compressor 23C, the pump 32P, the ultrasonic atomizer 32, the negative pressure pump 41, the motor 510 and the controller 200, respectively. On the other hand, the controller 200 issues control signals to the laser gun 21 , the air injection nozzle 23 , the spray nozzle 31 , the power supply equipment 90 , the motor 510 and the aerial work vehicle 400 .

Next, FIG. 6 shows a process explanatory diagram based on the decontamination system of FIG. First, in S1, an ON command is issued to the power supply equipment 90 to start the laser oscillator 21L, the air compressor 23C, the pump 32P, the ultrasonic atomizer 32 and the negative pressure pump 41 to prepare for decontamination. In S2, the laser gun 21, the air injection nozzle 23 and the spray nozzle 31 are synchronously operated to carry out the decontamination work. In S3', an automatic operation command is issued to the aerial work vehicle 400, an elevation drive command is issued to the lifting device 500, and the vehicle moves within the open wall work area. In S4, as a result of the movement, it is confirmed whether the end of the open wall work area has been reached and the decontamination work has been completed. (YES in S4), the process ends. In S3', the aerial work vehicle 400 can also move in a direction orthogonal to the plane of FIG. 5 (that is, a direction along the outer wall surface of the concrete retaining wall CW).

FIG. 7 is an explanatory diagram schematically showing a decontamination system for closed work areas in a building as a third example of the decontamination system according to the present invention. A decontamination system for a closed work area within a building (hereinafter simply referred to as a decontamination system) 3000 shown in FIG. (surface part) is decontaminated. The decontamination system 3000 includes a decontamination booth 10 (decontamination room) to which a suction mechanism 40 is connected and which forms a closed negative pressure space surrounding the surface portion S (see FIG. 2) of the concrete building CH, and a laser A laser irradiation mechanism 20 for irradiating the surface portion S of the concrete building CH with the beam LB, a water injection mechanism 30 (liquid injection mechanism) for injecting an ultrasonic atomized ultrasonic mist UM onto the surface portion S, and the laser irradiation mechanism 20. and a controller 200 (control unit) that issues a control signal to the water injection mechanism 30 .

Furthermore, the decontamination system 3000 is equipped with the decontamination booth 10, the laser irradiation mechanism 20, and the water injection mechanism 30, and the position with respect to the surface part S in the work area (inner wall surface and ceiling surface) to be decontaminated. A mobile work platform 600 (moving device) and a robot arm 700 (moving device) that can be changed by the controller 200 are arranged at a remote location outside the work area (inner wall surface and ceiling surface). The mobile work carriage 600 and the robot arm 700 move the decontamination booth 10, the laser irradiation mechanism 20, and the water injection mechanism 30 within the work area (inner wall surface and ceiling surface) according to control signals issued based on remote control by the controller 200. to change the position. A frame 11 of the decontamination booth 10 is connected to a mobile work cart 600 by a robot arm 700, and the tip of the frame 11 is equipped with casters 13 for moving on the inner wall surface and the ceiling surface.

The power supply facility 90 supplies driving power to the laser oscillator 21L, the air compressor 23C, the pump 32P, the ultrasonic atomizer 32, the negative pressure pump 41, the mobile work cart 600, the robot arm 700, and the controller 200, respectively. On the other hand, the controller 200 issues control signals to the laser gun 21, the air injection nozzle 23, the spray nozzle 31, the power supply equipment 90, the mobile work carrier 600, and the robot arm 700, respectively.

Next, FIG. 8 shows a process explanatory drawing based on the decontamination system of FIG. First, in S1, an ON command is issued to the power supply equipment 90 to start the laser oscillator 21L, the air compressor 23C, the pump 32P, the ultrasonic atomizer 32 and the negative pressure pump 41 to prepare for decontamination. In S2, the laser gun 21, the air injection nozzle 23 and the spray nozzle 31 are synchronously operated to carry out the decontamination work. At S3″, an automatic travel command is issued to the mobile work cart 600, and a rotation and telescopic drive command is issued to the robot arm 700 to move within the closed work area inside the building. It is confirmed whether or not the decontamination work has been completed by reaching the end, and if the end is not reached (NO in S4), the process returns to S2, and if the end is reached (YES in S4), the process ends.

FIG. 9 is an explanatory diagram schematically showing a decontamination system for a closed work area in a tunnel as a fourth example of the decontamination system according to the present invention. The decontamination system for a closed work area in a tunnel (hereinafter simply referred to as a decontamination system) 4000 shown in FIG. decontaminate. The decontamination system 4000 includes a decontamination booth 10 (decontamination room) to which a suction mechanism 40 is connected and which forms a closed negative pressure space surrounding the surface portion S (see FIG. 2) of the concrete tunnel CT, and a laser A laser irradiation mechanism 20 for irradiating the surface portion S of the concrete tunnel CT with the beam LB, a water injection mechanism 30 (liquid injection mechanism) for injecting the ultrasonic mist UM formed by ultrasonic atomization onto the surface portion S, and the laser irradiation mechanism 20. and a controller 200 (control unit) that issues a control signal to the water injection mechanism 30 .

Furthermore, the decontamination system 4000 is equipped with the decontamination booth 10, the laser irradiation mechanism 20, and the water injection mechanism 30, and can collectively change the position with respect to the surface part S in the work area (inclined inner surface) to be decontaminated. A mobile work carriage 600 (moving device) and a robot arm 700 (moving device) are further provided, and the controller 200 is placed at a remote location outside the work area (inclined inner surface). The mobile work carriage 600 and the robot arm 700 position the decontamination booth 10, the laser irradiation mechanism 20, and the water injection mechanism 30 within the work area (inclined inner surface) according to control signals issued based on remote control by the controller 200. change. A frame 11 of the decontamination booth 10 is connected to a mobile work cart 600 by a robot arm 700, and casters 13 are provided at the tip of the frame 11 for moving on an inclined inner surface.

The power supply facility 90 supplies driving power to the laser oscillator 21L, the air compressor 23C, the pump 32P, the ultrasonic atomizer 32, the negative pressure pump 41, the mobile work cart 600, the robot arm 700, and the controller 200, respectively. On the other hand, the controller 200 issues control signals to the laser gun 21, the air injection nozzle 23, the spray nozzle 31, the power supply equipment 90, the mobile work carrier 600, and the robot arm 700, respectively.

The process explanatory drawing based on the decontamination system of FIG. 9 is the same as that of FIG. 8, so it is omitted.

In addition, in each of the decontamination systems 1000, 2000, 3000, and 4000 (FIGS. 3, 5, 7, and 9), parts having functions common to those of the decontamination apparatus 100 (FIG. 1) are The same reference numerals are given and detailed description is omitted.

Moreover, these embodiments can be implemented in combination as appropriate within a range that does not cause technical contradiction. Furthermore, it is applicable not only to the radioactive substances described in the concrete structure CS (Fig. 2), but also to methods, devices, and systems for removing contaminants such as toxic substances, bacteria, etc. that pollute the environment such as air, water, soil, etc. can.

10 Decontamination booth (decontamination room)
11 Frame 12 Accordion Cover 13 Caster 20 Laser Irradiation Mechanism 21 Laser Gun 21F Optical Fiber 21L Laser Oscillator 22 Combined Lens 22S Objective Lens Surface 23 Air Injection Nozzle (Gas Injection Mechanism)
23C air compressor 23H air hose 30 water injection mechanism (liquid injection mechanism)
31 spray nozzle 32 ultrasonic atomizer (atomization mechanism)
32H hose 32P pump 32T tank 40 suction mechanism 41 negative pressure pump (suction fan)
42 dust collector 42F air filter 42H flexible hose 90 power supply facility 100 decontamination device 200 controller (control unit)
300 mobile work vehicle (moving device)
310 connecting bar (connecting mechanism)
1000 Decontamination system for road surface open work area (decontamination system)
400 aerial work vehicle (moving equipment)
500 lifting device (moving device)
510 motor 520 winding transmission mechanism 530 connection link (connection mechanism)
2000 Decontamination system for wall open work area (decontamination system)
600 mobile work cart (moving device)
700 robot arm (moving device)
3000 Decontamination system for enclosed work areas in buildings (decontamination system)
4000 Decontamination system for closed work areas in tunnels (decontamination system)
B Mounting table CS Concrete structure CA Coarse aggregate FA Fine aggregate CC Closed cell MC Mixed cell PP Contaminated piece S Surface part (contaminated layer)
CP concrete pavement (concrete structure)
CW concrete retaining wall (concrete structure)
CH concrete building (concrete structure)
CT concrete tunnel (concrete structure)
LB Laser beam UM Ultrasonic mist JA Injection air DA Contaminated air

Claims (12)

A method for decontaminating an inorganic structure containing inorganic solid particles, containing a large number of air bubbles, and having a contaminated layer at least on the surface thereof contaminated with a contaminant,
In a closed negative pressure space surrounding the surface portion, the surface portion is irradiated with a laser beam, and at the same time, atomized or atomized liquid is sprayed to the same location as the laser beam irradiation position to peel off the contaminated layer. - A decontamination method characterized by destroying and removing. A method for decontaminating a concrete structure containing inorganic solid particles as aggregate, containing a large number of fine closed cells, and forming a contaminated layer in which at least the surface portion is contaminated with a contaminant,
In a closed negative pressure space surrounding the surface portion, the surface portion is irradiated with a laser beam, and at the same time, atomized or atomized liquid is sprayed to the same location as the laser beam irradiation position to peel off the contaminated layer. - A decontamination method characterized by destroying and removing. The liquid sprayed toward the surface portion cools the surface portion heated by the laser beam to suppress melting,
3. The decontamination method according to claim 1 or 2, wherein the liquid that has entered the bubbles of the contaminated layer is rapidly heated by a laser beam and rapidly expands within the bubbles to peel and destroy the contaminated layer. 4. The decontamination according to any one of claims 1 to 3, wherein the irradiation of the laser beam and the injection of the liquid are performed continuously or intermittently on the same portion of the contaminated layer in synchronization with each other. Method. A decontamination apparatus for an inorganic structure containing inorganic solid particles, containing a large number of air bubbles, and forming a contaminated layer at least on the surface thereof contaminated with a contaminant,
a decontamination chamber to which a suction mechanism is connected and which forms a closed negative pressure space surrounding the surface portion;
a laser irradiation mechanism for irradiating the surface portion with a laser beam;
a liquid injection mechanism for injecting an atomized or atomized liquid onto the surface,
In the decontamination chamber, the laser irradiation mechanism irradiates the laser beam to the surface portion, and at the same time, the liquid injection mechanism sprays the atomized or atomized liquid to the same place as the laser beam irradiation position, so that the liquid is peeled off and destroyed. A decontamination device, wherein the suction mechanism sucks and removes the contaminated layer. A decontamination apparatus for a concrete structure that contains inorganic solid particles as aggregate, contains a large number of fine closed cells, and forms a contaminated layer in which at least the surface portion is contaminated with a contaminant,
a decontamination chamber to which a suction mechanism is connected and which forms a closed negative pressure space surrounding the surface portion;
a laser irradiation mechanism for irradiating the surface portion with a laser beam;
a liquid injection mechanism for injecting an atomized or atomized liquid onto the surface,
In the decontamination chamber, the laser irradiation mechanism irradiates the laser beam to the surface portion, and at the same time, the liquid injection mechanism sprays the atomized or atomized liquid to the same place as the laser beam irradiation position, so that the liquid is peeled off and destroyed. A decontamination device, wherein the suction mechanism sucks and removes the contaminated layer. 7. The decontamination apparatus according to claim 5, wherein the liquid injection mechanism ejects a mist having a particle size smaller than that of air bubbles in the contaminated layer by ultrasonic atomization. The laser irradiation mechanism includes a single lens or a combination lens for irradiating a laser beam, and the lens closest to the surface portion among these lenses to the objective lens surface which is the lens surface facing the surface portion. A gas injection mechanism for blowing air is provided,
8. The decontamination apparatus according to any one of claims 5 to 7, wherein the gas injection mechanism constantly blows air toward the objective lens surface during operation of the laser irradiation mechanism. A decontamination system for an inorganic structure containing inorganic solid particles, containing a large number of air bubbles, and forming a contaminated layer in which at least a surface portion is contaminated with a contaminant,
a decontamination chamber to which a suction mechanism is connected and which forms a closed negative pressure space surrounding the surface portion;
a laser irradiation mechanism for irradiating the surface portion with a laser beam;
a liquid injection mechanism for injecting an atomized or atomized liquid onto the surface;
a control unit that issues a control signal to the laser irradiation mechanism and the liquid ejection mechanism;
The controller causes the laser irradiation mechanism to irradiate the surface portion with a laser beam in the decontamination chamber, and at the same time, the liquid injection mechanism injects the atomized or atomized liquid to the same place as the irradiation position of the laser beam. A decontamination system, wherein a control signal is issued so that the suction mechanism suctions and removes the peeled/destroyed contaminant layer. A decontamination system for a concrete structure that contains inorganic solid particles as an aggregate, contains a large number of fine closed cells, and forms a contaminated layer in which at least a surface portion is contaminated with a contaminant,
a decontamination chamber to which a suction mechanism is connected and which forms a closed negative pressure space surrounding the surface portion;
a laser irradiation mechanism for irradiating the surface portion with a laser beam;
a liquid injection mechanism for injecting an atomized or atomized liquid onto the surface;
a control unit that issues a control signal to the laser irradiation mechanism and the liquid ejection mechanism;
The controller causes the laser irradiation mechanism to irradiate the surface portion with a laser beam in the decontamination chamber, and at the same time, the liquid injection mechanism injects the atomized or atomized liquid to the same place as the irradiation position of the laser beam. A decontamination system, wherein a control signal is issued so that the suction mechanism suctions and removes the peeled/destroyed contaminant layer. The decontamination chamber, the laser irradiation mechanism, the liquid injection mechanism, and the control unit are mounted or pulled, and the position of the work area to be decontaminated with respect to the surface is collectively controlled by the control signal emitted from the control unit. 11. A decontamination system according to claim 9 or claim 10, further comprising a moving device changeable as a In addition to mounting the decontamination chamber, the laser irradiation mechanism and the liquid injection mechanism, further comprising a moving device capable of collectively changing the position with respect to the surface part in the work area to be decontaminated,
The control unit is arranged at a predetermined position outside the work area,
9 or 10, wherein the moving device changes the positions of the decontamination chamber, the laser irradiation mechanism, and the liquid injection mechanism within the work area according to a control signal issued based on remote control by the control unit. 11. The decontamination system according to 10.

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