JP2022007913A - High-pressure washing gun unit for removing coating film and hood for high-pressure washing gun for removing coating film - Google Patents

Abstract

To provide a technique which decreases a scattering amount of washing water after ejection and/or a scattering amount of coating film pieces stripped from a basis material of a structure by collision with washing water, as the technique of stripping the existing coating film from the basis material of the structure by high-pressure ejection of washing water.SOLUTION: A hood 300 is mounted on a tip part of a washing gun 110 which performs high-pressure ejection of washing water and, thereby, a scattering amount of washing water which is ejected in mist state and/or a scattering amount of washing water which is brought into collision with a surface of the structure and is rebounded therefrom is decreased. The hood 300 has a tip part 304, and the tip part 304 is divided into a plurality of movable pieces 320 by a plurality of slits 310 which are extended in an ejection direction from a tip face thereof. Each movable piece 320 can be elastically deformed in a cantilever form. The washing gun 110 sweeps the surface of the structure in such a state that the hood 300 is closely attached to the surface of the structure in the whole circumference of the tip part 304.SELECTED DRAWING: Figure 21

Description

The present invention relates to a technique for injecting cleaning water at high pressure to remove an existing coating film from the substrate of a structure for cleaning, and in particular, during the high-pressure cleaning, the amount of scattered cleaning water after injection and / or Technology to reduce the amount of scattered coating pieces separated from the substrate of the structure due to collision with the washing water and / or technology to recover the washing water sprayed toward the structure as waste water and improve the degree of detoxification. It is about.

In certain cases, for example, since it was confirmed that harmful substances such as lead were present in the existing coating film adhering to the substrate of the structure, the notification dated May 30, 2014 from the Ministry of Health, Labor and Welfare was followed. When it is necessary, buildings (houses, buildings, etc.), steel towers that are elongated structures constructed using iron frame structures (for example, power transmission towers, communication steel towers, etc.), civil engineering structures In order to repaint the surface of a structure or structure such as (bridge, etc.), ship, vehicle (automobile, train, etc.), airplane, etc., the existing coating film already adhered to the surface is applied to the surface (base material) of the structure. A type of construction is then performed in which a new paint is applied on the same surface of the structure.

Here, as a method for peeling off the existing coating film, for example, as described in Patent Document 1, there are a physical method and a chemical method. Physical methods include hand tools such as scrapers, electric rotary tools that rotate removers such as wire brushes using an electric motor, air rotary tools that rotate similar removers using an air motor, and high-pressure water injectors. This is a method in which an operator uses a peeling machine or the like to peel off an existing coating film from a structure.

On the other hand, the chemical method is a method in which a release agent containing a chemical is applied to an existing coating film to dissolve or swell the existing coating film, thereby peeling the existing coating film from the structure. This method is also referred to as a wet coating film removing method using a coating film removing agent, that is, a wet coating film removing method, as described in Patent Document 1, for example.

There are various demands for the wet peeling method. For example, a request that the release agent has a small adverse effect on the environment (improvement of environmental response ability), a request that the release agent has a small adverse effect on the health of the worker (prevention of damage to the health of the worker), and work. There is a demand for high efficiency when a person performs peeling work (improvement of the peeling work efficiency of a worker), and a demand for a high ability of a peeling agent to peel off an existing coating film (improvement of peeling performance of a peeling agent). do.

Regarding the wet peeling method, Patent Document 1 describes the film thickness of the peeling agent layer (hereinafter, also referred to as “peeling agent layer” or “peeling agent coating film”) to be adhered on the existing coating film (hereinafter, “removing agent coating film”). For the purpose of increasing the "coating film thickness"), a surfactant is added to the release agent as a foaming agent before dipping the release agent, and the release agent is stirred in that state to make the release agent. It discloses a technique for mixing minute bubbles. If the coating film thickness of the release agent applied on the existing coating film is increased by dipping and the coating amount is increased, there is a possibility that the demands for improving the efficiency of the peeling work and the peeling performance are satisfied.

Further, Patent Document 2 discloses a technique of using an airless spray coating machine in order to expand the coating area of the release agent. However, Patent Document 2 does not disclose or suggest that it is useful to use an airless spray coating machine to increase the coating thickness of the release agent.

By the way, the present inventor has a practicality of carrying out the above-mentioned physical removal method alone for peeling a coating film, that is, without carrying out the above-mentioned wet peeling method, that is, using a peeling agent as an existing coating film. It was tested whether the existing coating film could be satisfactorily peeled off from the structure even if the above-mentioned physical removal method was carried out alone without applying it on top.

Here, just in case, to explain the definitions of the respective terms "peeling" and "removal" as important terms, both terms mean that the coating film separates from the structure in a broad sense. Common to each other in terms. However, the term "peeling" does not limit the form of separation in that the form of separation is "peeling" the coating film (eg, active film) from the surface of the structure in a tight adhesion state. It is different from the term "removal".

In that sense, the term "removal" constitutes a superordinate concept to the term "peeling". Therefore, the term "removal", in a broad sense, includes the term "peeling" and also means separation other than the form of "peeling". For example, when the coating film is not strong on the surface of the structure and is barely adhered to the surface of the structure due to softening, shrinkage, floating or peeling (for example, a deteriorated coating film). In addition, separating the coating film from the surface of the structure is more appropriate for "removal" than "peeling". Further, the phenomenon in which the peeling of the coating film and the mere separation of the coating film occur together may be generically referred to by the term "removal".

As a result of the above test, the present inventor has confirmed that under specific test conditions, when the physical removal method of any kind is carried out alone, almost all of the existing coating films are removed. It means that it could not be efficiently peeled off from the structure. Therefore, the practicality of carrying out the above-mentioned physical removal method alone for peeling the coating film could not be confirmed at least in this test.

Specifically, the present inventor tested the high-pressure washing method alone as a physical removal method under specific test conditions. As the specific test condition, there was an injection pressure condition that the injection pressure of the washing water from the spray gun was about 180 kgf / cm ² . In this test, stains on the surface of the existing coating film were removed, but the existing coating film itself was severely deteriorated, and only the portion that had already partially floated from the substrate was peeled off. Therefore, the practicality of carrying out the high-pressure cleaning method alone for peeling the coating film could not be confirmed at least in this test.

In addition, the present inventor has changed the above-mentioned injection pressure to ultra-high pressure, for example, about 800-1500 kgf / cm ² , for the practicality of carrying out the high-pressure cleaning method alone. I realized that if I did, it could be affirmed. However, the present inventor has also recognized that there may be new problems when implementing this ultra-high pressure cleaning method.

That is, the present inventor may have a physical danger to the worker if the ultra-high pressure washing water collides with the worker, and the amount of the ultra-high pressure washing water scattered after injection exceeds the controllable range. There is a possibility that the size of the coating piece that is peeled off from the base material of the structure due to collision with the ultra-high pressure washing water is large enough to exceed the controllable range, and the amount of scattering of the coating piece can be controlled. He recognized the possibility that there would be more than the range.

Further, when the physical removal method is carried out in combination with the wet peeling method as the previous step, the present inventor has a method of using an electric rotary tool, a method of using an air rotary tool, and a method of using the air rotary tool as the physical removal method. Tests were also conducted to evaluate the practicality of each of the high-pressure cleaning methods (including ultra-high pressure cleaning).

Based on the results of the test, the present inventor mutually evaluated the above-mentioned three types of physical removal methods from the viewpoint that the substrate of the structure is not easily damaged during the physical removal work of the existing coating film. We recognized that the high-pressure cleaning method was superior to other methods.

Several conventional examples of a high pressure cleaning method for removing a coating film are disclosed in Patent Document 3-7. Regarding the gun, a conventional example of a coating gun that injects paint at high pressure is disclosed in Patent Document 8, and a conventional example of a water jet gun for peeling a coating film is disclosed in Patent Document 9, which injects high-pressure water. A conventional example of a cancer is disclosed in Patent Document 10.

Japanese Unexamined Patent Publication No. 62-20575 Japanese Patent No. 6442101 Japanese Unexamined Patent Publication No. 9-170337 Japanese Unexamined Patent Publication No. 2009-179860 JP-A-2015-223531 Japanese Unexamined Patent Publication No. 2005-161286 Japanese Unexamined Patent Publication No. 2001-212298 JP-A-2002-096006 Japanese Unexamined Patent Publication No. 2020-040300 Japanese Unexamined Patent Publication No. 8-066644

Against the background of the above-mentioned prior art related to wet peeling, the present inventor has the above-mentioned four requests, that is, a request for improving the ability to respond to the environment, a request for preventing health damage to workers, and a request for peeling work. In order to simultaneously achieve at least two requests for efficiency and improvement of the release performance of the release agent, it is necessary to prevent the release agent from scattering when the release agent is applied, and to use the existing coating film. I realized that it is important to increase the coating film thickness and thus the coating amount of the release agent without dripping from the existing coating film on the surface.

Then, in the wet release agent application technique, the present inventor prevents the release agent from scattering when the release agent is applied, and the release agent applied on the surface of the existing coating film drips from the existing coating film. Research and development was carried out to make it possible to maximize the coating film thickness of the release agent and increase the coating amount and thus the coating amount at the same time.

Against these circumstances, some aspects of the present invention are wet release agent coating techniques, which prevent the release agent from scattering when the release agent is applied and on the surface of an existing coating film. The first object was to provide a material that enables the applied release agent to simultaneously increase the coating film thickness and the coating amount of the release agent without dripping from the existing coating film. Is.

Furthermore, the present inventor has noticed that there are some requests for high-pressure cleaning in the background of the above-mentioned prior art related to high-pressure cleaning.

First, from the viewpoint of work quality, there are the following multiple requests.

1. 1. The degree to which the base material of the structure is damaged by the wash water during the physical removal work of the existing coating film using the wash water (the amount by which the base material of the structure is scraped off, etc.) is reduced.

2. 2. The amount of washing water scattered after spraying (for example, the sum of the amount of washing water scattered before colliding with the structure and the amount of washing water scattered after colliding with the structure and bouncing off) is reduced.

3. 3. The amount of coating pieces peeled off from the base material of the structure due to collision with the washing water is reduced.

Further, from the viewpoint of work efficiency, there are a plurality of requests as follows.

1. 1. The amount of wash water scattered before colliding with the structure is reduced, thereby reducing the amount of wash water consumed without permission and thus the amount of water that needs to be used as wash water. To do.

2. 2. The recoil caused by the cleaning water ejected from the cleaning gun colliding with the surface of the structure is reduced.

3. 3. It is not necessary to re-clean the surface of the structure for repainting after peeling off the existing coating film with washing water.

In addition, from the viewpoint of environmental protection, there are the following multiple requests.

1. 1. The amount of coating pieces peeled off from the base material of the structure due to collision with the washing water is reduced.

2. 2. Hazardous substances mixed in the washing water after peeling and washing as wastewater (or wastewater) (for example, those contained in the existing coating film, those contained in the plating layer of the base material of the structure, and eluted in the washing water. To detoxify or attenuate things that contain (things).

3. 3. Reuse the detoxified or attenuated wastewater as new wash water.

Against these circumstances, some aspects of the present invention are to spray wash water at high pressure to exfoliate the existing coating from the substrate of the structure (eg, a zinc-plated layer as a protective layer of the structure). Provided is a technique for cleaning the structure, which reduces the amount of scattering of the washing water after injection and / or the amount of the coating piece peeled off from the substrate of the structure due to the collision with the washing water during the high-pressure washing. What was done as the second task.

Further, some aspects of the present invention are techniques for recovering and treating the washing water sprayed toward the structure as wastewater, and the washing water after peeling and washing as wastewater (or wastewater) is contained in the washing water. The third task is to provide a substance containing a mixed harmful substance and improving the degree of detoxification.

In order to solve the above-mentioned first problem, according to the first aspect of the present invention, there is a method of wet-peeling an existing coating film from a structure using a release agent.
The method is
By using an airless spray gun having a nozzle, the release agent itself is pressurized and the release agent is ejected from the nozzle without using compressed air, whereby the release agent is divided into a plurality of droplets. And the injection process that collides with the surface of the coating film.
In the coating step of applying the sprayed release agent onto the surface of the coating film, the plurality of droplets of the release agent collide with the surface of the coating film during the application, whereby the plurality of liquids are applied. Each of the droplets entrains air in the atmosphere and foams, whereby the plurality of droplets are adhered and fixed on the surface of the coating film as a plurality of air bubbles.
At least one of the viscosity of the release agent, the injection pressure when the release agent is ejected from the nozzle, and the average diameter of the nozzle is applied with the release agent using the airless spray gun. Provided is a coating film peeling method including a condition setting step of setting the atomizing property of the stripping agent to be poor.

In order to solve the above-mentioned first problem, according to the second aspect of the present invention, there is a method of wet-peeling an existing coating film from a structure using a release agent.
The method is
An injection step of injecting the release agent using an airless spray gun to divide it into a plurality of droplets.
The smaller the surface roughness of the existing coating film, the smaller the surface roughness of the coating film to be formed by applying the sprayed release agent onto the surface of the coating film and the release agent on the surface of the coating film. A coating film peeling method comprising a coating step of coating so as to have a large coating film thickness is provided.

In order to solve the above-mentioned second problem, according to the first aspect of the present invention, the existing coating film is removed from the surface of the structure by injecting washing water at high pressure to clean the surface of the structure. A high-pressure cleaning system for removing coating films that is removed.
A cleaning gun that injects cleaning water from an injection nozzle at high pressure,
A hood mounted on the cleaning gun that covers the injection nozzle and extends in the injection direction from the injection nozzle, whereby the amount and / or structure of the cleaning water ejected in the form of mist from the injection nozzle. Including those that reduce the amount of washing water that collides with the surface of an object and bounces off it.
The hood is made of a material that has elasticity at least at its tip,
The cleaning gun has a contact mode for high-pressure cleaning the structure in a state where at least a part of the tip of the hood is in contact with the surface of the structure, and a non-high pressure cleaning for the structure without the contact. A high pressure cleaning system for coating film removal is provided that can be used in at least the contact mode of the contact mode.

In order to solve the above-mentioned second problem, according to the second aspect of the present invention, the existing coating film is removed from the surface of the structure by injecting washing water at high pressure to clean the surface of the structure. A cleaning gun used to remove
A trigger as the main operating tool operated by one hand of the operator,
A flow rate adjusting valve that turns the cleaning gun on and off and adjusts the flow rate according to the amount of operation of the trigger.
An injection pressure adjuster as an auxiliary operation tool operated by the hand on the opposite side of the operator,
A high-pressure cleaning gun for removing a coating film including an injection pressure adjusting valve that adjusts the injection pressure of the cleaning water from the cleaning gun according to the operation amount of the injection pressure adjusting tool is provided.

In order to solve the above-mentioned second problem, according to the third aspect of the present invention, it is a coating film peeling method for peeling an existing coating film from a structure.
A wet peeling step of wetly stripping the existing coating film from the structure using a stripping agent.
After performing the wet peeling step, the process includes a high-pressure cleaning step of removing the existing coating film from the surface of the structure by injecting cleaning water at high pressure using a cleaning gun to clean the surface of the structure. The step of applying the release agent to the existing coating film for the purpose of using a high-pressure cleaning system for removing the coating film.
The spray nozzle of the wash gun is a flat blow nozzle, which allows the wash gun to spray wash water in a fan-shaped spray pattern, whereby the sprayed wash water is elongated. Provided is a coating film peeling method that collides with the surface of the structure in a momentary cleaning region.
In one example, the cleaning gun is configured to inject the cleaning water with an injection distance of about 50-about 200 mm, which is the distance from the injection nozzle to the target reach point on the structure. ..
Alternatively or additionally, in one example, the cleaning gun is configured to inject the cleaning water at an injection pressure of about 80-about 250 kgf / cm ² .
In place of or in addition to them, in one example, the cleaning gun is configured to inject the cleaning water at an injection rate of about 8-about 20 L / min.

In order to solve the above-mentioned third problem, according to the first aspect of the present invention, the existing coating film is removed from the surface of the structure by injecting washing water at high pressure to clean the surface of the structure. A high-pressure cleaning system for removing coating films that is removed.
Includes a wastewater treatment unit that collects and treats the sprayed wash water as wastewater.
The wastewater treatment unit comprises a double sheet installed on the scaffolding installed in the structure for the worker below its flooring.
The double sheet includes a filter sheet on the upper side and a water collecting sheet on the lower side, which are arranged so as to overlap each other in a plan view.
The filtration sheet is configured to receive the wastewater and filter the wastewater to remove coating pieces as solid matter from the wastewater.
The water collecting sheet is provided with a high-pressure cleaning system for removing a coating film, which is configured to receive the wastewater after filtration from the filtration sheet and to guide the wastewater after filtration to the wastewater outlet by using its own weight. To.

In order to solve the above-mentioned third problem, according to the second aspect of the present invention, the existing coating film is removed from the surface of the structure by injecting washing water at high pressure to clean the surface of the structure. A high-pressure cleaning system for removing coating films that is removed.
The wash water after high-pressure washing is collected and stored as wastewater, and at least one of an adsorbent such as a flocculant, a heavy metal insoluble agent, and an activated carbon powder is added to the wastewater containing harmful substances. A coagulation tank in which a predetermined harmful substance in the wastewater is coagulated, and
By filtering the wastewater in the coagulation tank, the wastewater is separated into a harmful substance as a solid substance and the wastewater after filtration from which the harmful substance has been removed, and a filtration unit.
High pressure for removing coating film, including an optional ion exchange fiber layer or ion exchange resin layer, which captures and recovers heavy metal ions in the waste water when the filtered waste water passes through the layer. A cleaning system is provided.

In order to solve the above-mentioned third problem, according to the third aspect of the present invention, the existing coating film is removed from the surface of the structure by injecting washing water at high pressure to clean the surface of the structure. It is a high-pressure cleaning method for removing the coating film to be removed.
The wash water after high-pressure washing is collected as wastewater and stored in a coagulation tank, and in the coagulation tank, wastewater containing harmful substances is mixed with a flocculant, a heavy metal insoluble agent, an adsorbent such as activated carbon powder, and the like. An agglomeration step of adding at least one to agglomerate a predetermined harmful substance in the wastewater.
A filtration step of filtering the wastewater in the coagulation tank to separate the wastewater into a harmful substance as a solid substance and a wastewater after filtration from which the harmful substance has been removed.
For removing a coating film, which is an optional step and includes a step of passing a wastewater after filtration through an ion exchange fiber layer or an ion exchange resin layer to capture and recover heavy metal ions in the wastewater. A high pressure cleaning method is provided.

Each of the following aspects is obtained by the present invention. Each aspect shall be divided into sections, each section shall be numbered, and the numbers of other sections shall be quoted as necessary. This is to facilitate understanding of some of the technical features that can be adopted by the present invention and their combinations, and the technical features that can be adopted by the present invention and their combinations are limited to the following aspects. Should not be interpreted as. That is, it should be interpreted that it is not hindered from appropriately extracting and adopting the technical features described in the present specification as the technical features of the present invention, which are not described in the following aspects.

Furthermore, describing each section in the form of quoting the numbers of the other sections does not necessarily prevent the technical features described in each section from being separated and independent from the technical features described in the other sections. It does not mean, and it should be interpreted that the technical features described in each section can be made independent as appropriate according to their properties.

(1) A method of wet-peeling an existing coating film from a structure using a release agent.
By using an airless spray gun having a nozzle, the release agent itself is pressurized and the release agent is ejected from the nozzle without using compressed air, thereby dividing the release agent into a plurality of droplets. The injection process and
In the coating step of applying the sprayed release agent onto the surface of the coating film, the plurality of droplets of the release agent collide with the surface of the coating film during the application, whereby the plurality of liquids are applied. Each of the droplets entrains air in the atmosphere and foams, whereby the release agent is applied on the surface of the coating film in a foamed state.
A coating film peeling method including a peeling step of physically peeling an existing coating film softened by the peeling agent from the structure after a lapse of a required time from the completion of the coating.

(2) The coating film peeling method according to item (1), wherein the stripping agent has a high viscosity.

(3) The coating film peeling method according to (1) or (2), wherein the stripping agent is a water-based stripping agent emulsion in which a main component and water are emulsified using a surfactant.

(4) The coating film peeling method according to item (1) or (2), wherein the stripping agent is a solvent-based stripping agent.

(5) In the coating step, the release agent is applied to the surface of the coating film so that the release agent in the foamed state has a plurality of bubbles having an average diameter in the range of about 0.1 mm to about 0.5 mm. The coating film peeling method according to any one of (1) to (4) to be applied above.

(6) In the coating step, the release agent is applied to the surface of the coating film so that the average coating film thickness of the coating film formed by applying the release agent onto the surface of the coating film is about 1 mm. The coating film peeling method according to any one of (1) to (5) to be applied above.

(7) In the coating step, the coating film is formed by the release agent being applied onto the surface of the coating film so that the average coating film thickness is in the range of about 2 mm to about 5 mm. The coating film peeling method according to any one of (1) to (5), wherein the stripping agent is applied onto the surface of the coating film.

(8) In the coating step, the coating film formed by the release agent being applied onto the surface of the coating film has a larger coating film thickness as the surface roughness of the existing coating film is smaller. The coating film peeling method according to any one of (1) to (7), wherein the peeling agent is applied onto the surface of the coating film.

(9) In the injection step, the release agent is pressurized with an injection pressure having a height that changes depending on the viscosity of the release agent and the amount of the release agent discharged from the nozzle, and is injected from the nozzle (9). The coating film peeling method according to any one of 1) to (8).

(10) The release agent is volatile and has
The coating film peeling method further
After the application of the release agent is completed, the surface of the coating film is wrapped with a protective sheet having impermeable property to the release agent, whereby the vaporized gas generated from the release agent is released from the surface of the coating film to the atmosphere. Includes a wrapping step to prevent it from being
The coating film peeling method according to any one of (1) to (9), wherein the peeling step includes a step of peeling the protective sheet from the existing coating film after the required time has elapsed.

(11) The injection step does not include a step of bringing the release agent into contact with the flow of compressed air to atomize the release agent by the principle of atomization, and further, the release agent is said to be before being injected from the nozzle. The coating film peeling method according to any one of (1) to (10), which does not include a step of foaming a peeling agent.

(21) A method of wet-peeling an existing coating film from a structure using a release agent.
The release agent has a high viscosity having a viscosity higher than 0.1 Pa · s, and has a high viscosity.
The method is
By using an airless spray gun having a nozzle, the release agent itself is pressurized and the release agent is ejected from the nozzle without using compressed air, whereby the release agent is divided into a plurality of droplets. And the injection process that collides with the surface of the coating film.
In the coating step of applying the sprayed release agent onto the surface of the coating film, the plurality of droplets of the release agent collide with the surface of the coating film during the application, whereby the plurality of liquids are applied. A coating film peeling method comprising a method in which each of the droplets entrains air in the atmosphere and foams, whereby the plurality of droplets are adhered and fixed on the surface of the coating film as a plurality of air bubbles.

(22) The coating film peeling method according to item (21), wherein the stripping agent has a viscosity not exceeding 16 Pa · s (20 ° C.).

(23) The coating film peeling method according to (21) or (22), wherein the stripping agent is a water-based stripping agent emulsion in which a main component and water are emulsified using a surfactant.

(24) The coating film peeling method according to item (21) or (22), wherein the stripping agent is a solvent-based stripping agent.

(25) The coating film peeling method according to any one of (21) to (24), wherein the spraying step sprays the stripping agent from the nozzle at a jet pressure not exceeding 80 kg / cm ² .

(26) In the coating step, the peeling agent is applied onto the surface of the coating film without recoating so that the average coating film thickness of the coating film formed is not less than about 1 mm. The coating film peeling method according to any one of (21) to (25), wherein the agent is applied onto the surface of the coating film.

(27) In the coating step, the average coating film thickness of the coating film formed by applying the release agent onto the coating film surface without recoating is within the range of about 2 mm to about 5 mm. The method for removing a coating film according to any one of (21) to (25), wherein the release agent is applied onto the surface of the coating film.

(28) The coating film peeling according to any one of (21) to (27), wherein in the coating step, the release agent is applied onto the coating film surface so as to have a coating amount of 1.0 kg / m ² . Method.

(29) In the injection step, the release agent is pressurized with an injection pressure having a height that changes depending on the viscosity of the release agent and the discharge amount of the release agent from the nozzle, and is injected from the nozzle (29). 21) The coating film peeling method according to any one of items (28) to (28).

(30) The release agent is volatile and has
The coating film peeling method further
After the application of the release agent is completed, the surface of the coating film is wrapped with a protective sheet having impermeable property to the release agent, whereby the vaporized gas generated from the release agent is released from the surface of the coating film to the atmosphere. The wrapping process to prevent it from being done,
Any of (21) to (29), which comprises a peeling step of peeling the protective sheet from the existing coating film after a lapse of a predetermined time, and further peeling the existing coating film softened by the release agent from the structure. The coating film peeling method described in the above.

(31) The injection step does not include a step of bringing the release agent into contact with the flow of compressed air to atomize the release agent by the principle of atomization, and further, the release agent is said to be before being injected from the nozzle. The coating film peeling method according to any one of (21) to (30), which does not include a step of foaming a peeling agent.

(51) A method of wetly peeling an existing coating film from a structure using a release agent.
The method is
By using an airless spray gun having a nozzle, the release agent itself is pressurized and the release agent is ejected from the nozzle without using compressed air, whereby the release agent is divided into a plurality of droplets. And the injection process that collides with the surface of the coating film.
In the coating step of applying the sprayed release agent onto the surface of the coating film, the plurality of droplets of the release agent collide with the surface of the coating film during the application, whereby the plurality of liquids are applied. Each of the droplets entrains air in the atmosphere and foams, whereby the plurality of droplets are adhered and fixed on the surface of the coating film as a plurality of air bubbles.
At least one of the viscosity of the release agent, the injection pressure when the release agent is ejected from the nozzle, and the average diameter of the nozzle is sprayed with the release agent using the airless spray gun. A coating film peeling method set so that the atomizing property of the stripping agent is deteriorated.

(52) The coating according to item (51), wherein at least one of the viscosity, the injection pressure, and the average diameter is set so that the average particle size of each of the plurality of droplets is larger than 50 μm. Membrane peeling method.

(53) The coating film peeling method according to (51) or (52), wherein the viscosity is set to a value higher than 0.1 Pa · s (20 ° C.).

(54) The coating film peeling method according to any one of (51) to (53), wherein the injection pressure is set to a height not exceeding 80 kg / cm ² .

(55) The coating film peeling method according to any one of (51) to (54), wherein the equivalent diameter is set to a value of 0.4 mm or more.

(56) The coating film peeling method according to any one of (51) to (55), wherein the viscosity is set to a value not exceeding 16 Pa · s (20 ° C.).

(57) In the coating step, the peeling is performed so that the average coating film thickness of the coating film formed by the release agent being applied onto the surface of the coating film without recoating is not less than about 1 mm. The coating film peeling method according to any one of (51) to (56), wherein the agent is applied onto the surface of the coating film.

(58) In the coating step, the average coating film thickness of the coating film formed by applying the release agent onto the coating film surface without recoating is within the range of about 2 mm to about 5 mm. The method for removing a coating film according to any one of (51) to (57), wherein the release agent is applied onto the surface of the coating film.

(59) The coating film peeling according to any one of (51) to (58), wherein in the coating step, the release agent is applied onto the coating film surface so as to have a coating amount of 1.0 kg / m ² . Method.

(60) In the injection step, the release agent is pressurized with an injection pressure having a height that changes depending on the viscosity of the release agent and the amount of the release agent discharged from the nozzle, and the release agent is injected from the nozzle (60). 51) The coating film peeling method according to any one of (59) to (59).

(61) The release agent is volatile and has
The coating film peeling method further
After the application of the release agent is completed, the surface of the coating film is wrapped with a protective sheet having impermeable property to the release agent, whereby the vaporized gas generated from the release agent is released from the surface of the coating film to the atmosphere. The wrapping process to prevent it from being done,
Any of (51) to (60), which comprises a peeling step of peeling the protective sheet from the existing coating film after a lapse of a predetermined time, and further peeling the existing coating film softened by the release agent from the structure. The coating film peeling method described in the above.

(62) The injection step does not include a step of bringing the release agent into contact with the flow of compressed air to atomize the release agent by the principle of atomization, and further, the release agent is said to be before being injected from the nozzle. Item 6. The coating film peeling method according to any one of (51) to (61), which does not include a step of foaming a peeling agent.

(63) A method of wet-peeling an existing coating film from a structure using a release agent.
The method is
An injection step of injecting the release agent using an airless spray gun to divide it into a plurality of droplets.
The smaller the surface roughness of the existing coating film, the smaller the surface roughness of the coating film to be formed by applying the sprayed release agent onto the surface of the coating film and the release agent on the surface of the coating film. A coating film peeling method including a coating step of applying so as to have a large coating film thickness.

(71) A high-pressure cleaning system for removing a coating film that removes an existing coating film from the surface of a structure by injecting cleaning water at a high pressure to clean the surface of the structure.
A cleaning gun that injects cleaning water from an injection nozzle at high pressure,
A hood mounted on the cleaning gun that covers the injection nozzle and extends in the injection direction from the injection nozzle, whereby the amount and / or structure of the cleaning water ejected in the form of mist from the injection nozzle. Including those that reduce the amount of washing water that collides with the surface of an object and bounces off it.
The hood is made of a material that has elasticity at least at its tip,
The cleaning gun has a contact mode for high-pressure cleaning the structure in a state where at least a part of the tip of the hood is in contact with the surface of the structure, and a non-high pressure cleaning for the structure without the contact. A high pressure cleaning system for coating film removal that can be used in at least the contact mode of the contact mode.

(72) The hood generally has a hollow thin-walled conical shape as a whole, and expands toward the end as it advances from the injection nozzle in the injection direction, and has a circular shape, an elliptical shape, or an oval shape as a cross-sectional shape. Item 3. The high-pressure cleaning system for removing a coating film according to (71), wherein the hood has a non-circular shape so as to have corners at at least one position in the circumferential direction of the hood.

(73) The high-pressure cleaning system for removing a coating film according to (71) or (72), wherein the material has at least a partial light transmission at at least a tip portion.

(74) The high-pressure cleaning system for removing a coating film according to any one of (71) to (73), wherein the material contains silicone at least at the tip thereof.

(75) The spray nozzle is a flat-blow nozzle, which allows the wash gun to spray wash water in a fan-shaped spray pattern, whereby the sprayed wash water is elongated. The high-pressure cleaning system for removing a coating film according to any one of (71) to (74), which collides with the surface of the structure in a momentary cleaning region.

(76) The cleaning gun injects the cleaning water in a state where the injection distance, which is the distance from the injection nozzle to the target arrival point on the structure, is about 50 to about 200 mm (71) to (75). ) The high-pressure cleaning system for removing the coating film according to any one of the items.

(77) The high pressure for removing a coating film according to any one of (71) to (76), wherein the cleaning gun is configured to inject the cleaning water at an injection pressure of about 80 to about 250 kgf / cm ² . Cleaning system.

(78) The high-pressure cleaning for removing a coating film according to any one of (71) to (77), wherein the cleaning gun is configured to inject the cleaning water at an injection rate of about 8 to about 20 L / min. system.

(79) The cleaning gun is
A trigger as the main operating tool operated by one hand of the operator,
A flow rate adjusting valve that turns the cleaning gun on and off and adjusts the flow rate according to the amount of operation of the trigger.
An injection pressure adjuster as an auxiliary operation tool operated by the hand on the opposite side of the operator,
Item 3. The high pressure for removing a coating film according to any one of (71) to (78), which includes an injection pressure adjusting valve that adjusts the injection pressure of the washing water from the washing gun according to the operation amount of the injection pressure adjusting tool. Cleaning system.

(80) Further, the present invention includes a wastewater treatment unit that collects and treats the washing water ejected from the injection nozzle as wastewater.
The wastewater treatment unit comprises a double sheet installed on the scaffolding installed in the structure for the worker below its flooring.
The double sheet includes a filter sheet on the upper side and a water collecting sheet on the lower side, which are arranged so as to overlap each other in a plan view.
The filtration sheet is configured to receive the wastewater and filter the wastewater to remove coating pieces as solid matter from the wastewater.
The water collecting sheet is configured to receive the wastewater after filtration from the filtration sheet and guide the wastewater after filtration to the wastewater outlet by using its own weight. High-pressure cleaning system for removing coating film described in Crab.

(81) The wastewater treatment unit further includes
The filtered wastewater discharged from the wastewater outlet is collected and stored, and at least one of an adsorbent such as a flocculant, a heavy metal insoluble agent, and an activated carbon powder is added to the wastewater containing a harmful substance. As a result, a coagulation tank in which a predetermined harmful substance in the wastewater is agglomerated, and
By filtering the wastewater in the coagulation tank, the wastewater is separated into a harmful substance as a solid substance and the wastewater after filtration from which the harmful substance has been removed, and a filtration unit.
Item (80) includes an optional ion exchange fiber layer or ion exchange resin layer that captures and recovers heavy metal ions in the waste water when the filtered waste water passes through the layer. The high pressure cleaning system for coating film removal described.

(82) The wastewater treatment unit further includes
A reuse means for reusing the detoxified wastewater that has passed through the filtration unit and discharged from the filtration unit as new washing water.
The high-pressure cleaning system for removing a coating film according to item (81), which comprises a dehydration means for dehydrating wet flocs that do not pass through the filtration unit but remain there and contain the harmful substances.

(83) A high-pressure cleaning method for removing a coating film, which removes an existing coating film from the surface of the structure by injecting cleaning water at high pressure to clean the surface of the structure.
The method is a cleaning gun that injects cleaning water from an injection nozzle at high pressure, and covers the injection nozzle and extends from the injection nozzle in the injection direction, whereby the cleaning water injected in the form of mist from the injection nozzle. And / or with a hood-equipped hood that reduces the amount of wash water that collides with and / or bounces off the surface of the structure.
The method is
The first step of using the cleaning gun in a contact mode for high pressure cleaning of the structure in a state where at least a part of the tip of the hood is in contact with the surface of the structure.
A second step in which the cleaning gun is used in a non-contact mode for high-pressure cleaning the structure without contacting the surface of the structure in the hood, which is optionally performed.
Regardless of which of the first step and the second step is carried out, in parallel with the step to be carried out, the washing gun is jetted with the washing water, which is elongated and instantaneously collided with the surface of the structure. A high-pressure cleaning method for removing a coating film, which comprises a third step of moving and sweeping in a direction intersecting the cleaning area.

(91) A method of removing an existing coating film from the surface of a painted structure by collision with high-pressure washing water.
Mechanical removal of the existing coating film from the surface of the structure by injecting cleaning water from the injection port of the cleaning gun under pressure using a hand-held cleaning gun, and the structure thereof. A high-pressure washing process that cleans the surface of the surface with washing water, and
When the sprayed washing water collides with the structure, the washing water as a liquid component and the coating piece as a solid component, which is a coating piece, are physically collided with the washing water from the surface of the structure. Includes a wastewater treatment step that treats the wastewater produced as a mixture with the stripped and removed material.
In the high-pressure washing step, the amount of the washing water ejected from the washing gun to be scattered laterally from the planned flight path when the washing water flies in the air exceeds a predetermined allowable value. Not like
(A) The injection pressure, which is the pressure of the cleaning water at the injection port of the cleaning gun,
(B) The injection angle, which is the apex angle of the fan-shaped spray pattern that spreads toward the end as the shape of the flight path when the cleaning water is injected from the injection port of the cleaning gun and then flies in the air.
(C) Distribution of pressure in each cross section of the fan-shaped spray pattern of the washing water sprayed from the injection port of the washing gun.
(D) Two conditions are set for at least two of the four control variables including the injection amount, which is the amount of the washing water injected from the injection port of the washing gun per unit time, and the set conditions. The cleaning water is sprayed from the cleaning gun under the above conditions.
The wastewater treatment step is
A wastewater recovery process in which the wastewater is collected and stored in a container installed at a predetermined position at a high-pressure washing site related to the structure.
A coagulation step of adding a flocculant to the wastewater contained in the container to coagulate harmful substances existing in the wastewater.
A separation step of separating and recovering the aggregated harmful substances from the wastewater by filtering the wastewater to which the flocculant is added.
At the work site related to the structure, the component of the wastewater after filtration is analyzed by using the analysis kit, and the component of the wastewater is a predetermined wastewater standard and the standard regarding the transparency of the wastewater after filtration is set. An analysis process to determine whether or not to satisfy what you have,
When it is determined that the components of the wastewater satisfy the wastewater standard, the wastewater / reuse step of draining the wastewater or reusing it for the next high-pressure washing,
When it is determined that the components of the wastewater do not meet the wastewater standard, a high-pressure washing type coating film removing method including the agglomeration step, the agglomerate recovery step, and the repeating step of repeating the analysis step for the wastewater. ..

(92) The structure is made of metal, the surface of the structure is coated with a galvanized layer, and the galvanized layer is coated with the existing coating film.
Item (91): The high-pressure washing step is carried out under injection conditions in which damage to the galvanized layer due to washing water is substantially minimized, whereby the rust-preventing ability of the structure is substantially maintained. The high pressure cleaning type coating film removing method described.

(93) The injection conditions are
The injection pressure condition that the injection pressure is in the range of about 80-about 250 kgf / cm ² and
The injection angle condition that the injection angle is in the range of about 10 to about 15 degrees, and
Pressure distribution conditions in which the pressure distribution of the sprayed wash water in each cross section of the fan-shaped spray pattern is substantially uniform, and
The high-pressure washing type coating film removing method according to item (91) or (92), which cumulatively includes an injection amount condition that the injection amount is in the range of about 8 to about 20 L / min.

(94) The high-pressure washing step is
Prior to applying the release agent onto the existing coating film, the washing water is sprayed toward the existing coating film, whereby the release agent is to be applied on the surface of the existing coating film. A pre-cleaning step of cleaning the existing coating film and removing the portion of the existing coating film that has risen from the surface of the structure before applying the release agent.
After the existing coating film is swollen and softened on the structure by the release agent applied on the existing coating film, the washing water is sprayed toward the existing coating film, whereby the existing coating film is formed. The high-pressure cleaning type coating film removing method according to any one of (91) to (93), which comprises a production cleaning step of peeling and removing from the structure.

(95) The first injection pressure is less than about 50%, less than about 60%, less than about 70%, less than about 80% or less than about 90% of the second injection pressure (94). High-pressure cleaning type coating film removal method.

(96) The high-pressure washing according to any one of (91) to (95), wherein the washing gun has a recoil reducing means for reducing the recoil caused by the washing water jetted from the washing gun colliding with the structure. Mold coating film removal method.

(97) The reaction reducing means injects compressed air in the cleaning gun in the direction opposite to the injection direction of the cleaning water when the cleaning water is injected and in coaxial with the injection direction. The high-pressure cleaning type coating film removing method according to (96), wherein the reaction is at least partially canceled by the second reaction generated by the compressed air ejected from the same cleaning gun colliding with the surrounding static air. ..

(98) In the wastewater recovery step, a water collecting sheet installed in a variable position so as to surround a work site that moves sequentially in the structure and a drain hose extending from the water collecting sheet are used. The high-pressure washing type coating film removing method according to any one of (91) to (97), wherein the wastewater is collected at a work site and the collected wastewater is supplied to the container.

(99) The harmful substance contains heavy metals (lead, etc.), chromium and PCB.
The flocculant is
The condition that the harmful substances are selectively aggregated and
The condition that the content concentration of the harmful substance in the wastewater after filtration is lower than the predetermined reference value is satisfied.
The high-pressure washing type coating film removing method according to any one of (91) to (98), which is selected so as to cumulatively satisfy the condition that the transparency of the wastewater after filtration exceeds a predetermined reference value.

(101) A cleaning gun unit used for removing an existing coating film from the surface of a structure by injecting cleaning water at a high pressure to clean the surface of the structure.
A cleaning gun that injects cleaning water from an injection nozzle at high pressure,
Attached to its cleaning gun, including a generally hollow thin-walled conical hood,
The hood covers the injection nozzle and extends divergently in the injection direction from the injection nozzle, and has a main body portion close to the cleaning gun and a tip portion away from the cleaning gun.
The tip portion is divided into a plurality of movable pieces by a plurality of slits extending from the tip surface of the hood in a direction generally opposite to the injection direction and extending to a boundary line between the tip portion and the main body portion.
Each movable piece is a high-pressure cleaning gun unit for removing a coating film, which has a thin plate shape and is supported by the main body in a cantilever shape and elastically bendable.

(102) The cleaning gun is stopped or moved with respect to the structure in contact with the surface of the structure in one or more of the movable pieces of the hood. The high-pressure cleaning gun unit for removing a coating film according to item (101), which is capable of high-pressure cleaning of the structure.

(103) In the cleaning gun, when the surface of the structure is swept in contact with the surface of the structure in the one or a plurality of movable pieces, the structure has an obstacle protruding from the surface of the structure. The high-pressure cleaning gun for removing a coating film according to item (102), wherein the one or a plurality of movable pieces facing the obstacle can overcome the obstacle by its own elastic deformation. unit.

(104) The cleaning gun unit is described in any one of (101) to (103), wherein the cleaning gun unit sweeps the surface of the structure in a state where the hood is in contact with the surface of the structure on the entire circumference of the tip portion. High-pressure cleaning gun unit for removing coating film.

(105) The item according to any one of (101) to (104), wherein the hood has a non-circular shape so as to have corners at at least one position in the circumferential direction of the hood as a cross-sectional shape. High pressure cleaning gun unit for removing coating film.

(106) Mist-like from the injection nozzle of the cleaning gun to the cleaning gun used to remove the existing coating film from the surface of the structure by injecting cleaning water at high pressure to clean the surface of the structure. A hood that is removable or non-detachable to reduce the amount of scatter of the wash water sprayed in and / or the amount of scatter of the wash water that collides with the surface of the structure and bounces off the surface.
The hood is generally hollow, thin-walled and conical.
The hood covers the injection nozzle and extends divergently in the injection direction from the injection nozzle, and has a main body portion close to the cleaning gun and a tip portion away from the cleaning gun.
A plurality of movable pieces extending from the tip surface of the hood in a direction generally parallel to the injection direction are arranged at the tip thereof along the circumferential direction of the tip, and each movable piece is formed. The first configuration, which is supported by the main body in a cantilevered and elastically flexible manner,
At least one of the second configuration in which the hood is configured to form a non-circular shape so as to have corners at at least one position in the circumferential direction of the hood as a cross-sectional shape is adopted. Hood for high-pressure washing gun for removing membranes.

FIG. 1 is a system diagram conceptually representing an exemplary airless coating machine used to carry out a coating film peeling method according to an exemplary first embodiment of the present invention. FIG. 2 is a table showing the composition and operating temperature of each of a plurality of types of release agents, that is, removers, which are selectively used in the airless coating machine shown in FIG. FIG. 3 is a process diagram showing an exemplary preparatory step in the coating film peeling method. FIG. 4 is a process diagram showing an exemplary construction process in the coating film peeling method. FIG. 5 is a diagram conceptually showing the temporal transition of the properties of the remover ejected from the nozzle of the airless spray gun shown in FIG. FIG. 6 is a diagram showing the test results of the coatability of a remover coated on an existing coating film according to an embodiment of the present invention in comparison with a comparative example. FIG. 7A shows the viscosity of the release agent before being sprayed from the airless spray gun when the liquid release agent is airlessly applied, and the particle size of each of the plurality of droplets in which the release agent is divided by the spray. It is a graph conceptually showing the general relationship established between (for example, the average diameter) and the atomization property of the release agent by the airless spray gun, and FIG. 3B is an airless in the same spray environment. 6 is a graph conceptually showing a general relationship established between the injection pressure of a release agent from a spray gun and the particle size of each of the droplets. FIG. 8 shows the thickness of the film to which the release agent should be applied on the surface of the existing coating film according to the surface roughness of the existing coating film when the coating film peeling method according to the first embodiment is carried out. It is a graph which conceptually shows an example of the process which determines the average coating film thickness. FIG. 9 is a process diagram showing an example of a coating film peeling method according to an exemplary second embodiment of the present invention. FIG. 10 is a partial cross-sectional side view showing a cleaning gun in the coating film removing high pressure cleaning system used to perform the high pressure cleaning in FIG. 11 (a) is a front view showing the hood shown in FIG. 10 taken out, and FIG. 11 (b) is a cross-sectional view showing a base end portion of the hood. 12 (a) is a perspective view showing a spray pattern of the washing water sprayed from the washing gun shown in FIG. 10, and FIG. 12 (b) is an enlarged front view showing the spray nozzle of the washing gun taken out. It is a figure. 13 (a) is a perspective view for explaining how the hood shown in FIG. 10 is geometrically fitted to the inside corner of the angle member in the structure as a work object, and FIG. 13 (b) is a perspective view. It is a side view for chronologically explaining how the hood overcomes the exposed portion of the bolt fastened to the angle member by elastic deformation during the sweeping of the cleaning gun shown in FIG. c) is a front view for explaining how the hood elastically deforms when it gets over the exposed portion of the bolt. FIG. 14A is a graph for conceptually explaining the relationship between the amount of sprayed water and the impact pressure as a plurality of cleaning force characteristics of the cleaning gun shown in FIG. 10, and FIG. 14B is a graph for explaining the injection angle. It is a graph for conceptually explaining the relationship between and impact pressure. FIG. 15A is a graph for conceptually explaining the relationship between the injection pressure and the impact pressure as a plurality of different cleaning force characteristics of the cleaning gun shown in FIG. 10, and FIG. 15B is a graph for explaining the relationship between the injection pressure and the impact pressure. It is a graph for conceptually explaining the relationship between the injection distance and the impact pressure. FIG. 16 is a perspective view for conceptually explaining a plurality of places and a plurality of directions in which the washing water is scattered when the washing gun shown in FIG. 10 injects the washing water and collides with the washing surface. FIG. 17A is a perspective view showing an example of a double sheet as a part of the wastewater treatment unit used for carrying out the wastewater treatment in FIG. 9, and FIG. 17B is a perspective view thereof. It is a side view which shows the water collecting sheet among the double sheets. FIG. 18 is a perspective view showing an example of the remaining portion of the wastewater treatment unit shown in FIG. FIG. 19 is a process diagram showing an example of wastewater treatment shown in FIG. FIG. 20 is a process diagram showing another example of the coating film peeling method shown in FIG. FIG. 21 is a perspective view showing a high-pressure cleaning gun unit for removing a coating film used for performing high-pressure cleaning in the coating film peeling method according to an exemplary third embodiment of the present invention. 22 (a) is a cross-sectional view showing an example of the shape of a corner portion of the hood of the cleaning gun unit shown in FIG. 21, and FIG. 22 (b) is another example of the shape of the corner portion. It is sectional drawing which shows. 23 (a) is a plan view showing each movable piece shown in FIG. 21 together with an obstacle of the structure, and FIG. 23 (b) shows a side surface showing each movable piece shown in FIG. 21 together with the obstacle of the structure. It is a figure, and FIG. It is a side view which shows the dynamic behavior at the time of getting over in time series. FIG. 24 is a side sectional view showing how the cleaning gun unit sweeps the cleaning surface in an inclined posture with respect to the cleaning surface. FIG. 25 (a) is a perspective view showing how the cleaning gun unit simultaneously sweeps the inner two surfaces of the angle material as the structure, and FIG. 25 (b) shows the cleaning gun unit using the structure. It is a perspective view which shows the state which the outer two surfaces of the angle material are swept at the same time. FIG. 26 is a partial front sectional view for explaining an example of a method of attaching the hood shown in FIG. 21 to the cleaning gun shown in the figure. FIG. 27 is a plan view showing an example of a sheet material for manufacturing the hood shown in FIG. 21 by bending. FIG. 28 is a perspective view illustrating the hinge of each movable piece of the hood shown in FIG. 21.

[First Embodiment]

Hereinafter, an exemplary first embodiment of the present invention will be described in detail with reference to the drawings.

An exemplary embodiment of the present invention relates to a wet peeling method for stripping an existing coating film from a structure (or a structure) using a stripping agent (hereinafter, also referred to as “remover”). Specifically, the wet peeling method is a foaming airless coating peeling method in which a peeling agent is applied onto an existing coating film by foaming airless (airless injection, air spraying) and peeled off.

An example of the foaming airless coating peeling method is a method of applying a foaming airless coating on an existing coating film and peeling.

Here, "high viscosity" means, for example, a viscosity higher than the viscosity limit (for example, 0.1 Pa · s (20 ° C.)) at which general coating is possible when expressed in terms of paint viscosity. For example, "high viscosity" means a viscosity corresponding to a gel coat paint (3 Pa · s (20 ° C.)) or higher, or a viscosity corresponding to mayonnaise (23 ° C.) (8 Pa · s (20 ° C.)). )) Or higher viscosity may be meant.

Another example of the effervescent airless coating peeling method is a method in which a highly viscous and emulsified stripping agent is applied on an existing coating film by effervescent airless coating and peeled. An example of a highly viscous and emulsified release agent is the first remover shown in FIG. 2, as will be described later.

The above-mentioned foaming airless coating peeling method (hereinafter referred to as “main peeling method”) includes a foaming airless coating step S201 as a chemical peeling step and a physical method, as will be described in detail later with reference to FIG. The peeling step S203 as a specific (mechanical) peeling step is provided as a plurality of steps carried out in the order thereof.

FIG. 1 conceptually shows an exemplary airless coating machine 10 used for carrying out the above-mentioned foaming airless coating step S201 in a system diagram.

The airless coating machine 10 includes a tank 30 for storing a release agent 20 applied on the existing coating film 14 in order to wetly remove the existing coating film 14 from the structure or the structure 12, and an airless type pressure pump 40 (airless type pressure feeding pump 40). It has a pressure feeder), an airless spray gun (hereinafter, simply referred to as “spray gun”) 50, and an air compressor 60 as a drive source of the pressure feed pump 40. The type of the spray gun 50 may be a hand-held hand gun or an automatic gun.

Specifically, the air compressor 60 exerts a high pressure on the pressurizing chamber 76 located behind the plunger or piston described below, thereby causing a discharge chamber (high viscosity to be discharged) located in front of the plunger or piston. The release agent 20 is used to pressurize the room 80 from which the tank 30 is fed.

The airless spray method using the spray gun 50 will be described in detail later with reference to FIG. 5, but to briefly explain, a high pressure is applied to the release agent 20 to form a liquid film, and the liquid film is formed into the atmosphere (static air). This is a method of atomizing the release agent 20 into droplets.

The tank 30 is connected to the supply port 72 of the pressure feed pump 40 via a hose 70. The supply port 72 is fluidly connected to the discharge port 80. The air compressor 60 is connected to the pressurizing chamber 76 of the pressure feed pump 40 via the air hose 74. The spray gun 50 is connected to the discharge chamber 80 of the pressure feed pump 40 via a high pressure hose 78. In the airless coating machine 10, the hose 70 constitutes a supply line, the air hose 74 constitutes a compressed air line, and the high pressure hose 78 constitutes a pumping line.

The spray gun 50 pressurizes the release agent 20 itself by the plunger or the piston and injects the release agent 20 from the nozzle without bringing the compressed air into direct contact with the release agent 20, whereby the release agent 20 is plurality. It is configured to be divided into droplets of.

<Setting of spray factor>

In the present embodiment, the spray factor, that is, the viscosity of the release agent 20, the injection pressure when the release agent 20 is ejected from the nozzle (“atomic pressure”), and the average diameter of the nozzle. At least one is set so that the atomizing property of the release agent 20 when the release agent 20 is sprayed by using the airless spray gun 50 is deteriorated.

The reason for setting the spray factor so that the atomizing property of the release agent 20 is deteriorated will be described in detail later, but will be briefly described as follows.

That is, when the atomizing property of the stripping agent 20 is deteriorated, the average particle size of each of the plurality of droplets from which the stripping agent 20 is divided by spraying is good in atomizing property. Become bigger. On the other hand, the larger the average particle size, the larger the momentum (= mv) of each droplet when each droplet flies in the static air, and the higher the ability to penetrate the static air, and as a result, each liquid. The flight speed of the droplets is faster than when each droplet is small. As a result, the impact energy (collision energy) when each droplet collides with the surface of the existing coating film 14 becomes larger than when the atomization property is good.

FIG. 7A shows the viscosity of the release agent 20 before being sprayed from the airless spray gun 50 when the liquid release agent 20 is airlessly applied, and a plurality of droplets in which the release agent 20 is separated by the spray. The general relationship established between each particle size (eg, average diameter) and the atomization property of the release agent 20 by the airless spray gun 50 is conceptually represented in the graph.

Specifically, the higher the viscosity, the larger the particle size, which results in poor atomization. In one example, it is defined that the atomizing property is good in the region where the particle size is 50 μm or less, whereas the atomizing property is poor in the region where the particle size is larger than 50 μm.

Further, in FIG. 3B, the general relationship established between the injection pressure of the release agent 20 from the airless spray gun 50 and the particle size of each of the droplets is conceptualized in a graph in the same spray environment. It is represented as a target. Specifically, the lower the injection pressure, the larger the particle size, which results in poor atomization. Similar to the above, in one example, the atomization property is good in the region where the particle size is 50 μm or less, whereas the atomization property is poor in the region where the particle size is larger than 50 μm. Defined.

Then, in the present embodiment, the viscosity of the release agent 20 is set to a value higher than 0.1 Pa · s (20 ° C.) in order to deteriorate the atomization property. However, the higher the viscosity, the more desirable it is, and there is an upper limit. The upper limit is, for example, 16 Pa · s (20 ° C.). The upper limit is necessary because if the viscosity is too high, the release agent 20 may not atomize at all.

Further, in the present embodiment, the injection pressure is set to a height not exceeding 80 kg / cm ² in order to deteriorate the atomization property.

Further, in the present embodiment, the equivalent diameter of the nozzle (hereinafter, also referred to as “nozzle diameter”) is set to a value of 0.4 mm or more in order to deteriorate the atomization property. This is because the smaller the equivalent diameter, the easier it is for the release agent 20 to atomize, whereas the larger the nozzle diameter, the more the release agent 20 is maintained in a liquid state and less likely to be atomized.

Furthermore, the spraying conditions that impair the atomization property will be expanded.

In the spray gun 50, the pressure acting on the release agent 20 (for example, the injection pressure described later) is usually about 80-200 kg / cm ² , but in the present embodiment, for example, 30 as described later. The pressure is lower than the normal value, such as -40 kg / cm ² .

The spray gun 50 may adopt either a diaphragm type, a plunger pump type using a plunger, or a piston pump type using a piston as a method for discharging the release agent 20 as a material from the nozzle of the spray gun 50. However, when the release agent 20 has a high viscosity, it is desirable to adopt a plunger pump type or a piston pump type.

Further, since the spray gun 50 has a low injection pressure as described above, a pressure feed type (a release agent 20 is added) as a method of feeding the release agent 20 as a material into the discharge chamber in the spray gun 50. Rather than pressing and pushing out), a gravity type (using a natural fall to inject the release agent 20) or a blow-up type (using an air flow to blow up and inject the release agent 20) may be adopted. However, a pressure feed type may be adopted.

Regardless of which method is adopted, the spray gun 50 is configured to have a main body 90 and a nozzle tip 92 that is detachably attached to the main body 90. The main body 90 is configured to include a grip 94 gripped by the operator and a trigger 96 operated by the operator.

The nozzle tip 92 has a nozzle into which the release agent 20 is sprayed. The cross-sectional shape of the nozzle can be, for example, circular, elliptical, or slit. In the present embodiment, the cross-sectional shape of the nozzle is elliptical, and the equivalent diameter of the nozzle is 0.59 mm (within the range of 0.4 to 0.8 mm). Here, the "equivalent diameter" means the outer diameter of the circular region when the opening region of the nozzle opening is replaced with a circular region having the same area.

The discharge amount of the release agent 20 from the spray gun 50 (also referred to as an injection amount, defined as, for example, the weight of the release agent 20 discharged from the nozzle per fixed time) and the spraying pattern depend on the shape of the nozzle.

In the present embodiment, when the target spraying pattern of the release agent 20 from the elliptical nozzle of the spray gun 50 is viewed from the side (the direction perpendicular to the long axis of the cross-sectional shape of the elliptical nozzle), for example, It is an isosceles triangle (fan shape) that widens as it progresses in the injection direction. In that triangle, for example, the height (spray distance) is about 25 cm and the base length (pattern width) is about 15-20 cm. be.

Further, in the present embodiment, when the elliptical nozzle is adopted, when the injection pressure is 60 kg / cm ² , the injection amount is 1490 mL / min and the injection pressure is 30-40 kg / cm ² . When the injection amount is 750-1000 mL / min.

Features of the spray gun 50

The spray gun 50 applies pressure to the release agent 20 itself by forcibly injecting the release agent 20 from the nozzle without depending on air blowing.

To explain the principle that the release agent 20 is atomized by the airless spray method using the spray gun 50, first, as shown in FIG. 5, the release agent 20 is ejected from the nozzle as a liquid film at high pressure. The tip of the liquid film collides with the surrounding static air, which causes the velocity of the tip of the liquid film to gradually decrease. On the other hand, since the pressure for injecting the release agent 20 is constant, the liquid film becomes wavy. As the wavy liquid film travels in the static air, it receives resistance from the static air, and the wavy liquid film splits into a plurality of parts arranged in the traveling direction of the liquid film.

After that, each split liquid film extends in a direction intersecting with the traveling direction, and is formed into a concavo-convex string so as to repeat concave portions and convex portions in the extending direction.

The uneven string-shaped portion is then divided into a plurality of droplets arranged in the extending direction thereof, whereby the release agent 20 is formed into droplets.

By the way, since the spray gun 50 directly sprays the high-pressure release agent 20, the amount of the release agent 20 scattered is smaller than that of the air spray gun, and the coating efficiency (for example, the total weight We of the sprayed release agent 20) is reduced. Of the sprayed release agent 20, the portion coated on the existing coating film 14 (excluding the scattered portion) is defined as the ratio of the amount W).

That is, since the spray gun 50 atomizes and applies the release agent 20 without using air, the amount of the release agent 20 atomized and scattered in the air is small, which causes health hazards to the environment and workers. The amount is small, and the coating efficiency of the release agent 20 (for example, the coating efficiency) is high.

Further, since the release agent 20 can be applied while supplying the release agent 20 to the spray gun 50, it is suitable for streamlining the release work.

Since the spray gun 50 can apply the release agent 20 on the existing coating film 14 at a higher pressure than that of the air spray gun, a thick film of the release agent 20 can be formed on the existing coating film 14.

However, since the spray gun 50 sprays a larger amount of the release agent 20 than the air spray gun, the release agent 20 applied on the existing coating film 14 tends to drip unless additional measures are taken. ..

Therefore, in the present embodiment, some measures have been added in order to improve the adhesiveness (adhesiveness, adhesiveness, etc.) of the release agent 20 onto the existing coating film 14.

(1) Foaming of the release agent 20 by optimizing the injection factor

In comparison with the air spray gun, according to the experiment of the present inventor, the higher the injection pressure of the release agent 20 from the spray gun 50 (for example, the higher the pressure acting on the spray gun 50 from the air compressor 60). It has been found that the spraying speed of the release agent 20 from the spray gun 50 is increased and the cross-sectional diameter (spraying diameter) of the spraying pattern (for example, conical shape) is reduced.

Further, as described above, by optimizing the injection factor, that is, by combining the combination of increasing the viscosity of the release agent 20, lowering the injection pressure and increasing the diameter of the nozzle, the particle size of each droplet of the release agent 20 can be increased. The diameter is increased, which increases the flight speed of each droplet as it flies in static air.

As described above, in the present embodiment, by optimizing such an injection factor, each droplet is speeded up in combination with the adoption of the airless spray gun 50 instead of the air spray gun.

Due to the high speed of each droplet, the impact energy when each of the above-mentioned droplets collides with the existing coating film 14 increases, and each droplet becomes finer due to the collision, and the total number of droplets increases, and as a result, The surface area of the droplet as a whole, that is, the contact area with static air, increases. As a result, the droplets entrain more static air and foam. As a result, each droplet is made finer, whereby a larger number of bubbles (air bubbles) are formed in the release agent 20 as a whole.

On the other hand, in the release agent 20 having the same coating film thickness, the larger the number of air bubbles, the lighter the weight of each air bubble, and the more difficult it is for each air bubble to flow on the existing coating film 14 due to its own weight. As a result, it is presumed that the adhesiveness of the release agent 20 on the existing coating film 14 is improved, and as a result, the coating film thickness of the release agent 20 on the existing coating film 14 is increased. Further, the thicker the coating film thickness of the release agent 20, the more the release agent 20 is applied to the existing coating film 14 (also referred to as the coating amount, for example, the release agent 20 applied per fixed area (or fixed time)). (Defined as weight) increases.

From the experiments of the present inventor, it has been found that the injection pressure is preferably in the range of 30-60 kg / cm ² or in the range of 30-40 kg / cm ² . The numerical value is that the pattern in which the release agent 20 is sprayed from the spray gun 50 is the above-mentioned target spraying pattern, and the release agent 20 is not sufficiently atomized from the spray gun 50 (without atomization). It is desirable to set it so that it reaches on the film 14.

(2) Additional effect of increasing the viscosity of the release agent 20

Generally, when a high-viscosity release agent is applied, unlike the case where a low-viscosity release agent is used, when the coating film of the release agent requires a thickness, the release agent flows in the coating film. It is prevented from dripping.

From the experiment of the present inventor, it has been found that the higher the viscosity of the release agent 20, the better the adhesiveness of the release agent 20 on the existing coating film 14.

Furthermore, the experiment of the present inventor has revealed that it is desirable that the paint viscosity of the release agent 20 is as high as about 5 to about 16 Pa · s (20 ° C.).

(3) High degree of emulsification of release agent 20

According to the experiment of the present inventor, as the degree of emulsification of the release agent 20 is higher, the number of bubbles generated in the release agent 20 due to the collision with the existing coating film 14 increases and the bubbles become finer, and as a result, the existing coating film 14 It has been found that the adhesiveness of the release agent 20 to the top is improved.

According to this finding, as the release agent 20, an emulsion, that is, an aqueous release agent (for example, the first remover in FIG. 2) was adopted.

However, according to the experiment of the present inventor, even if the release agent 20 is a non-emulsion, that is, a solvent-based release agent (for example, the second to fourth remover in FIG. 2), the coating thickness of the release agent 20 is conventionally determined. It was found that the coating method, that is, the method using an air spray gun or the method using a brush coating, is thicker.

<Component composition of release agent 20>

The release agent 20 contains a main component, an auxiliary agent, and a thickener, regardless of the type.

The main component contains an organic solvent in order to swell the existing coating film 14 and easily peel it off from the surface of the structure 12. Examples of the organic solvent include an alcohol-based high boiling point solvent, an ester-based organic solvent, and a complex cyclic organic solvent.

The auxiliary agent exists for stabilizing the properties of the release agent 20, and includes, for example, aromatic hydrocarbon solvents, terpenes and the like.

The thickener is present so that the release agent 20 can be applied onto the existing coating film 14 in a predetermined amount to prevent dripping, and examples thereof include silicate compounds and organic bentonite.

<Variations in the composition of the release agent 20>

As shown in FIG. 2, in the present embodiment, there are four types of release agents 20 that can be applied onto the existing coating film 14 by the spray gun 50, such as the first to fourth removers.

Among them, the first remover is a water-based release agent (emulsion), while the second-fourth remover is a solvent-based release agent (non-emulsion).

Furthermore, the 1st and 2nd removers show normal reactivity and are recommended for use in the high temperature period when the average temperature is higher than about 10 ° C, whereas the 3rd remover has an average temperature of less than about 10 ° C. Even in the low temperature period, it shows normal reactivity and its use is recommended.

Since the fourth remover contains dichloromethane, safety management measures are required to prevent health hazards of workers, but it dries faster than other removers and exhibits strong peeling power. It is recommended to use this 4th remover for partial repair.

1. 1. Solvent-based release agent

It contains an organic solvent as a main component (20-90%), and also contains an auxiliary agent, a thickener and the like as an auxiliary component.

2. 2. Water-based stripper

It contains an organic solvent as a main component (30-50%), and also contains an auxiliary agent, a thickener and the like and water (35-50%) as auxiliary components.

In general, water-based strippers are less hazardous than solvent-based strippers.

The water-based release agent is an emulsion in which the main component and water are emulsified using a surfactant.

<Foam type airless coating peeling method>

The foaming type airless coating peeling method according to the present embodiment has a preparation step S100 shown in FIG. 3 and a construction step S200 shown in FIG. 4 so as to be carried out in the order thereof.

<Preparation process>

As shown in FIG. 3, first, in step S101, the operator investigates the existing coating film 14 to be peeled off. Specifically, the existing coating film factors such as the material, coating film thickness, and surface texture (for example, surface roughness μmRmax) of the existing coating film 14 and the structure factors such as the structure and shape of the structure 12 are investigated.

Next, in step S102, the operator selects the construction time for peeling off the existing coating film 14. If the construction time is selected, the average temperature of the environment at the construction time is predicted. The average temperature is referred to to determine which of the four types of removers described above is optimal.

Subsequently, in step S103, the operator selects the peeling condition. Specifically, one of the first to fourth removers in FIG. 2 is selected as the release agent 20 to be used this time, based on the above-mentioned existing coating film factor and / or structure factor for the existing coating film 14. .. At this time, as described above, the release agent 20 used this time is selected so as to have a viscosity suitable for deteriorating the atomization property of the release agent 20 in airless coating.

Further, it is determined how many times the peeling operation using the peeling agent 20 this time is repeated according to the factor including the investigated coating thickness. Further, the target coating film thickness of the release agent 20 in each peeling operation is determined based on the existing coating film factor and / or the structure factor described above.

Specifically, among the existing coating film factors, the release agent 20 is formed by being adhered to the surface of the existing coating film 14 according to the surface roughness (for example, unit: μmRmax) of the existing coating film 14. Determine the target coating film thickness (average coating film thickness, etc.) of the coating film to be applied.

More specifically, according to a predetermined relationship, the target coating film thickness of the release agent 20 is determined according to the surface roughness of the existing coating film 14, so that the smaller the surface roughness, the thicker the target coating film. ..

FIG. 8 conceptually shows an example of the relationship between the surface roughness of the existing coating film 14 and the target coating film thickness of the release agent 20. The lower the surface roughness, that is, the higher the surface smoothness, the more the total area of the release agent 20 in contact with the microscopic surface of the existing coating film 14 when the release agent 20 is applied to the surface of the existing coating film 14. (The total area of the microscopic surface in consideration of surface irregularities, hereinafter referred to as "microscopic total contact area") is narrow.

The wider the microscopic total contact area for the projected area of the surface of the existing coating film 14 (that is, the total area of the macroscopic surface ignoring the surface unevenness), the more the release agent 20 can apply the existing coating film 14 at once. While the peeling speed is high, the smaller the total microscopic contact area, the lower the speed at which the peeling agent 20 peels off the existing coating film 14 at one time, so that the peeling agent 20 takes more time. It is desirable to keep in contact with the existing coating film 14.

Therefore, in order to maximize the peeling speed of the release agent 20, the lower the surface roughness of the existing coating film 14, the thicker the coating film of the release agent 20, thereby each part of the surface of the existing coating film 14. In addition, it is desirable that the release agent 20 laminated in the film thickness direction keeps contacting one after another from the portion close to the surface.

In addition, it may be assumed that the relationship between the surface roughness of the existing coating film 14 and the target coating film thickness of the release agent 20 is the opposite of that described above.

Specifically, the higher the surface roughness of the existing coating film 14, the larger the total microscopic contact area for the macroscopic total area. Therefore, the coating film of the release agent 20 is thickened to match it. It is also assumed that it is effective to increase the total coating amount by increasing the amount of the release agent 20 in contact with each part of the microscopic surface of the existing coating film 14 among all the parts. Can be done.

Further, the target coating amount is determined from the target coating thickness determined as described above. Further, the target discharge amount of the release agent 20 from the spray gun 50 is determined according to the determined target application amount, and in some cases, the nozzle tip 92 to be used this time is selected. However, at this time, as described above, the nozzle tip 92 used this time is selected so as to have an equivalent diameter suitable for deteriorating the atomization property of the release agent 20 in airless coating.

Further, according to the viscosity of the release agent 20 this time and the target discharge amount of the release agent 20 from the nozzle, the spray gun 50 pressurizes the release agent 20 this time and determines the injection pressure when the release agent 20 is ejected from the nozzle. do. However, at this time, as described above, the injection pressure is selected so as to have a height suitable for deteriorating the atomization property of the release agent 20 in airless coating.

<Construction process>

As shown in FIG. 4, first, in step S201, the operator implements the above-mentioned foaming airless coating method on the existing coating film 14.

The foaming airless coating method includes a preparatory step in which the worker prepares or procures the release agent 20 and puts it into the tank 30, and the worker activates the pressure pump 40, thereby. It has a pressure feeding step of pumping the release agent 20 from the tank 30 to the spray gun 50 in an airless state.

In the foam type airless coating method, the operator further grasps the spray gun 50 and aims at the target, that is, the existing coating film 14, and pulls the trigger 96 in that state, whereby a plurality of release agents 20 are applied from the spray gun 50. It has an injection step of dividing into droplets and injecting them toward a target.

The injection step does not include a step of bringing the release agent 20 into contact with the flow of compressed air to atomize the release agent 20 by the principle of mist blowing, and further, the release agent 20 before injecting the release agent 20 from the nozzle 92. Does not include the step of foaming.

The foam-type airless coating method further includes a coating step in which the operator applies the sprayed release agent 20 onto the surface of the existing coating film 14.

In the coating step, during the coating, the plurality of droplets of the release agent 20 collide with the surface of the existing coating film 14, whereby the plurality of droplets entrain air in the atmosphere and foam. As a result, the release agent 20 is applied onto the surface of the existing coating film 14 in a foamed state.

In one example, the release agent 20 is previously applied so that the coating step has a plurality of bubbles in which the foamed release agent 20 has an average diameter in the range of about 0.1 mm to about 0.5 mm. It is carried out so as to be applied on the surface of the film 14.

In another example, the release agent 20 is such that the coating step has an average coating film thickness of about 1 mm, which is formed by applying the release agent 20 on the surface of the existing coating film 14. Is applied onto the surface of the existing coating film 14.

In yet another example, in the coating step, the average coating film thickness of the coating film formed by the release agent 20 being applied onto the surface of the existing coating film 14 is within the range of about 2 mm to about 5 mm. As described in the above, the release agent 20 is applied onto the surface of the existing coating film 14.

In any of the examples, the existing coating film 14 is swollen and softened by the release agent 20, and the adhesive force to the surface of the structure 12 is reduced, and as a result, the existing coating film 14 is lifted from the surface of the structure 12.

Next, in step S202, after the application of the release agent 20 is completed, the operator wraps the surface of the existing coating film 14 with a protective sheet having impermeableness to the release agent 20, whereby the release agent 20 ( It prevents the vaporized gas generated from (when it has volatility) from being released to the atmosphere from the surface of the existing coating film 14. The protective sheet is, for example, a flexible polyethylene sheet, a polypropylene sheet, or the like.

According to the experiment of the present inventor, as an effect of the wrapping, the release of vapor (vaporization gas) from the release agent 20 applied on the existing coating film 14 is prevented, whereby about 90% of the vapor is discharged from the existing coating film. It was confirmed that it penetrated into 14 and promoted the efficiency of the peeling work.

Subsequently, in step S203, after the required time (for example, 16-48 hours) has elapsed from the completion of the coating, the operator peels off the protective sheet from the existing coating film 14 and removes it. After that, the operator physically peels off the existing coating film 14 that has been lifted from the surface of the structure 12 due to the reduced adhesive force due to the release agent 20 from the structure 12 and removes it.

In order to physically peel off the existing coating film 14 from the structure 12, the operator may use a scraper as a hand tool.

Further, in order to remove the coating film residue which is a part of the existing coating film 14 remaining on the surface of the structure 12 after the first peeling operation, a wire brush as an electric rotary tool (for example, a cup-shaped wire brush) is used. ) Or an air grinder may be used.

Since this removal work imposes a heavy burden on the operator, it is important that the electric rotary tool is as light as possible and that the peeled coating film residue does not scatter. Therefore, it is desirable that the electric rotary tool is small in size and the rotating portion rotates at a lower speed than usual.

Further, if necessary, the operator may additionally or optionally use a high pressure washer to remove the existing coating film 14 and / or coating film residue.

According to the present embodiment, in order to achieve the target coating thickness of the release agent 20, a brush or a roller requires a plurality of coating operations, but the target coating thickness is set once. It can be realized by coating work, and work efficiency is improved.

Further, in the present embodiment, the release agent 20 is installed in-line from the installation location (in FIG. 1, the main body portion of the airless coating machine 10 excluding the spray gun 50 is fixedly installed) (work with the main body portion). The spray gun 50, which is a place, can be fed to the work place (in a state where the spray gun 50 is connected to each other by a continuous pumping line 78).

Specifically, the main body of the airless coating machine 10 (particularly, the pressure pump 40) and the spray gun 50 are connected to each other by a hose (line) 78 that serves as both a pressure transmission path and a material supply path. .. As a result, unlike the case of air coating (spray coating), the main body (particularly, the pressure pump 40) and the spray gun 50 can be connected to each other by both a pressure transmission path and a material supply path that are independent of each other. It becomes unnecessary.

As a result, the release agent 20 can be reliably supplied to the spray gun 50. Specifically, the release agent 20 is unplanned while the release agent 20 is being supplied from the main body to the spray gun 50. It will not leak to the work floor or the like and the part will not be contaminated with the release agent 20.

<Adhesiveness test>

Types of release agent 20 used in the adhesiveness test

The type of the release agent 20 used in the coatability test is the first remover (high viscosity emulsion) shown in FIG. A specific example of the first remover has the following component composition.

Moisture: 40-50% by weight
Alcohol solvent: 40-50% by weight
Petroleum solvent: 1-5% by weight
Surfactant: 1-5% by weight
Thickener: 1-5% by weight
Rust preventives: less than 1% by weight Waxes: less than 1% by weight

Moreover, the specific example has the following properties.

Appearance: Viscosity liquid exhibiting white or pale yellow Viscosity: 5-16 Pa · s (20 ° C)

Example

260 g of release agent 20 and airless coating using a spray gun 50 on a 500 × 500 mm steel sheet for coating as a test piece, whereby a coating amount (coating density, spraying density) of 1.0 kg / m ² was applied to the test piece. Was realized.

After the application, the test piece was hung vertically, and the test piece was photographed after 5 minutes in order to observe the dripping condition of the release agent 20. The photograph is attached to the upper part of FIG.

Comparative example

260 g of release agent 20 and a brush (not shown) are applied to a 500 × 500 mm steel sheet for coating as a test piece, whereby a coating amount (coating density, spraying) of 1.0 kg / m ² is applied to the test piece. Density) was realized.

After the application, the test piece was hung vertically, and the test piece was photographed after 5 minutes in order to observe the dripping condition of the release agent 20. The photograph is attached to the bottom of FIG.

Contrast observation

In the examples, dripping of the release agent 20 (for example, traces of the release agent 20 flowing, unplanned behavior of the release agent 20 due to gravity such as dropping of the release agent 20) could not be observed at all. Further, the surface of the release agent 20 applied to the test piece was smooth.

As is clear from the upper photograph of FIG. 6, in the example, it was confirmed that the release agent 20 applied to the test piece did not flow down from the test piece at all.

Further, the average coating thickness of the release agent 20 adhered to and fixed to the test piece without dripping from the test piece (for example, the coating thickness when applied only once without recoating) is about 2 mm to about. It was also confirmed that it was within the range of up to 5 mm.

Furthermore, it was also confirmed that the release agent 20 in a foamed state on the test piece had a plurality of bubbles having an average diameter in the range of about 0.1 mm to about 0.5 mm.

On the other hand, in the comparative example, dripping (or flow, flow line) of the release agent 20 was observed over the entire area of the test piece. Further, on the surface of the release agent 20 applied to the test piece, a material flow occurred and a streak-like uneven pattern was present.

As is clear from the photograph at the bottom of FIG. 6, in the comparative example, it was confirmed that a part of the release agent 20 applied to the test piece flowed down from the test piece.

In addition, in order to confirm the effect of the present embodiment, the inventor of the present invention refers to a steel tower as a building having a surface on which the release agent is difficult to spread due to its complicated shape. The peeling work was actually performed using the foaming type (foaming promotion type) airless coating peeling method according to the embodiment. As a result, it was confirmed that the peeling work was ensured, that is, the existing coating film was peeled to every corner, and that the efficiency was improved, that is, the time for the peeling work was shortened.

Further, in the above description of the present embodiment, the phenomenon that the release agent 20 foams is referred to as static air in the process in which the release agent 20 ejected from the spray gun 50 flies in the static air. The plurality of droplets split from the release agent 20 do not become air bubbles due to the collision, and only when they collide with the existing coating film 14, the plurality of droplets become air bubbles and the release agent 20 foams on the existing coating film 14. It was described as an embodiment.

However, in the process in which a plurality of droplets of the release agent 20 fly in the static air, the present invention may be implemented in such a manner that at least a part of the droplets becomes an air bubble due to the collision with the static air. Do not exclude.

[Second Embodiment]

Next, an exemplary second embodiment of the present invention will be described in detail with reference to the drawings. However, for the elements common to the first embodiment, redundant description will be omitted by quoting using the same name or reference numeral, and only different elements will be described in detail.

FIG. 9 shows an example of a coating film peeling method according to the present embodiment in a process diagram.

In this coating film peeling method, wet peeling as an example of the chemical removal method is carried out in step S1. This wet peeling may be the same as or different from that according to the first embodiment described above. For example, this wet peeling may be carried out by applying a stripping agent on the existing coating film 14 by an airless spray method of a type that does not foam at all or promotes foaming.

In this coating film peeling method, high-pressure cleaning as an example of the physical removal method is subsequently carried out in step S2. This high-pressure washing is carried out in combination with the wet peeling as a previous step, but may be carried out alone.

In the present embodiment, in order to carry out the high-pressure washing, a coating film configured to wash the surface of the structure 12 by high-pressure spraying of washing water and physically remove the existing coating film 14 from the surface. A high pressure cleaning system for removal (hereinafter, simply referred to as “high pressure cleaning system”) 100 is used. The high pressure cleaning system 100 will be described in detail later with reference to FIGS. 10-19.

In this application, the term "washing water" is not a term chosen with the intent of eliminating liquids other than water, but is commonly used as synonymous with the term "washing liquid". To.

In this coating film peeling method, after that, in step S3, the cleaning water (conventionally synonymous with the cleaning liquid) sprayed from the cleaning gun 110 (see FIG. 10) in the high-pressure cleaning system 100 is wastewater (conventional wastewater). Wastewater treatment is carried out to collect and treat as (synonymous with). The wash gun 110 will be described in detail later with reference to FIGS. 10-16. A wastewater treatment unit 200 is used to carry out the wastewater treatment. The wastewater treatment unit 200 will be described in detail later with reference to FIGS. 17-19.

Here, in the present embodiment, the technical background of combining the wet peeling with the high pressure washing and the wastewater treatment will be described.

Generally, as a method of removing an existing coating film (old coating film) that is softened and swollen on the surface of a structure by a release agent and lifted from the surface, a scraper as a hand tool, a rotary tool, etc. are used by an operator. By using it manually, and by contacting a rigid member such as a wire brush or a razor with a narrow machining area on the surface of the structure, the machining area can be scratched, scraped, or polished by the rigid member. Then, a method of removing the existing coating film from the surface of the structure has already been proposed.

On the other hand, in general, a high-pressure cleaning method in which an operator sprays cleaning water at high pressure to remove an existing coating film has already been proposed. This high-pressure cleaning method is a cleaning method in which the existing coating film is peeled off by using the impact force of water and then washed away, and the surface of the structure is not directly rubbed.

This high-pressure cleaning method has an advantage over the above-mentioned method of removing a coating film using a scraper or a rotary tool, because it does not rub the surface of the structure directly, so that the surface of the structure is not damaged. Since the area that can be washed at one time is wide, there is an advantage that the removal work is highly efficient.

In addition, this high-pressure cleaning method is essentially a constriction that cannot be penetrated by a rotary tool, and complex shapes such as around bolts and nuts (for example, rotary tools such as rotary wire brushes and rotary shavings are not points but surfaces. Since it comes into contact with the surface of the structure, the tool contact point when the rotary tool comes into contact with the structure cannot be moved as freely as in the case of point contact, which makes it difficult to remove the coating film). Even if is present in the structure, there is an advantage that the washing water is applied around the complicated shape portion, whereby the existing coating film can be completely removed.

However, at present, the latter method has not been put into practical use. This is because the high-pressure jetted wash water may scatter before colliding with the structure and may scatter when it collides with the structure and bounces off. The amount of cleaning water required for work may increase and work efficiency may decrease, and the cleaning water scattered when bouncing off the structure is contained in the existing coating film or the plating layer of the base material of the structure. This is because if the harmful substances are mixed in, the harmful substances may be scattered along with the scattering of the washing water, which may pollute the environment.

Therefore, in the present embodiment, the high-pressure cleaning method is realized in a state where the above-mentioned potential drawbacks are overcome while maintaining the above-mentioned essential advantages.

Specifically, the high pressure cleaning system 100 reduces the effect of harmful substances on the environment, that is, the harmful substances are substantially (for example, practically acceptable) in relation to the environment. To achieve detoxification
(1) The cleaning gun 110 is configured so that the cleaning water after injection does not scatter from the scaffold 210 (see FIG. 13), and further.
(2) The wastewater treatment unit 200 does not deviate from the scaffold 210 even if the washing water and the coating film mixed therein are scattered when the washing water collides with the structure 14 and bounces off. It is configured to be virtually entirely captured and detoxified.

<Washing gun>

In FIG. 10, the cleaning gun 110 is shown in a partial cross-sectional side view.

The cleaning gun 110 has a main body portion 112 and a hollow tubular portion 114, and the base end portion of the tubular portion 114 is connected to the main body portion 112.

The main body 112 has a flow control valve (valve opening: 0% fully closed-100% fully open) 120. The flow control valve 120 is fluidly connected to a high pressure source (eg, a pump) 124 via a flexible hose 122 and is fluidly connected to a fluid passage 126 in the cylinder 114. The high pressure source 124 pumps wash water before use from the tank 125.

The main body 112 further has a grip 130 gripped by one hand of the operator and a trigger 132 operated by the fingers of the same hand. The flow rate control valve 120 is turned on and off according to the operation position of the trigger 132, and the valve opening degree of the flow rate control valve 120 is adjusted in the on state (valve opening degree is larger than 0%).

In the present embodiment, the cleaning gun 110 adjusts the injection pressure by adjusting the injection water amount, which is the amount of cleaning water injected from the cleaning gun 110 in the on state (for example, fully open state) of the flow control valve 120. It has an injection pressure adjuster (valve opening: 0% fully closed-100% fully open) 140. The operator can operate the injection pressure adjuster 140 at the same time with the other hand while pulling the trigger 132 with one hand.

Here, the injection pressure adjusting tool 140 is also a mechanism for adjusting the amount of injected water. This is because a certain interlocking relationship is established between the two, such that the injection pressure decreases when the injection water amount decreases, and conversely, the injection pressure increases when the injection water amount increases.

In one example, the injection pressure adjuster 140 has an operation unit 142 that is manually rotated by an operator, and the injection pressure adjuster 140 is mounted in the middle of the tubular portion 114.

By the way, assuming a site where a worker performs high-pressure cleaning on a structure 12, the properties of the existing coating film 14 to be removed (for example, for each work site (individual target cleaning surface) in the structure 12). The higher the degree of adhesion to the structure 12, the higher the injection pressure is required.) And the shape of the structure 12 (for example, the more complicated the shape, the more frequently the direction in which the washing water hits the washing surface fluctuates. Since the amount of scattering increases, the injection pressure is lowered to reduce the amount of injection water). On the other hand, in order to preserve the environment, it is important to minimize the amount of each of the washing water and the coating piece.

Therefore, in the present embodiment, during the series of work, the worker sprays the washing water at a high injection pressure for one work part in order to give priority to the removal of the coating film, while the worker scatters the other work part. In order to inject cleaning water at a low injection pressure to prioritize prevention, the operator frequently operates the injection pressure regulator 140 during work, i.e., with the cleaning gun 110 continuously on. It is possible to do.

<Spray nozzle>

The cleaning gun 112 has a nozzle portion 150 connected to the tip portion of the tubular portion 114. The nozzle portion 150 has a hollow nozzle cover 152 connected to the tip end portion of the tubular portion 114 and a nozzle tip 154 detachably attached to the nozzle cover 152 in a state of being fluidly communicated with the fluid passage 126. Have.

As shown in FIG. 11B, the nozzle tip 154 is formed with an injection nozzle 156, and the injection nozzle 156 is an injection hole as an outlet for the washing water to be injected and discharged at a high pressure. Has 160.

In the present embodiment, the injection nozzle 156 is configured to realize flat blowing and fan-shaped spraying (spray pattern) as illustrated in FIG. 11A. Specifically, the injection hole 160 has an elongated rectangular shape having a hole width W, as illustrated in FIG.

<Food>

As shown in FIG. 10, the cleaning gun 110 has a hood 170 detachably attached to the tip of the tubular portion 114. The hood 170 is attached to the cleaning gun 110 so as to extend from the injection nozzle 154 in the injection direction while covering the injection nozzle 154. The cleaning gun 110 and the hood 170 form a cleaning gun unit in the assembled state.

As a protective device attached to the tip of the cleaning gun 110, the hood 170 prevents the cleaning water ejected in the form of mist from the injection nozzle 154 from scattering laterally, as illustrated in FIG. It is configured as follows. Further, the hood 170 captures the wash water that collides with and bounces off the surface of the structure 12 after injection, thereby reducing the amount of the bounced wash water scattered.

That is, the hood 170 captures the washing water that scatters immediately after the injection and also catches the washing water that collides with the surface of the structure 12 and rebounds after the injection, whereby the washing water before and after the collision is scattered. It has the function of reducing the amount.

<Outer shape of the hood>

As shown in FIG. 10, the hood 170 generally has a divergent conical shape as a whole, and specifically, a base end portion 172 mounted on the tip end portion of the tubular portion 114 and a base end portion 172 thereof. It has a cone portion 174 extending in a divergent manner from the tip surface of the surface. The axial length A of the cone portion 174 is about 100-about 150 mm, and the maximum diameter B of the cone portion 174 is about 150 mm.

In the present embodiment, there are a plurality of types of hoods 170, which are selected by the operator according to the situation at the site and the shape of the work target portion in the structure 12, and the selected type. Hood 170 is attached to the cleaning gun 110.

<Cross-sectional shape of the hood>

As the plurality of types of hoods 170, although not shown, a conical type having a circular cross section in which the cone portion 174 gradually expands in diameter as it advances in the axial direction, and a conical type having a circular cross section, as illustrated in FIGS. 12 and 13, are outside the radial direction. There is a modified cone type having a non-circular cross section formed by a combination of a triangle that is convex in the direction and a partial circle.

Here, the cross section of the cone portion 174 belonging to the "cone type" may be circular, elliptical, oval, or polygonal.

Further, the "non-circular cross section" is, for example, a shape formed by combining a semicircle and a triangle (for example, a right-angled triangle, a triangle having a generally right-angled apex angle, etc.) at the diameter of the semicircle and the base of the triangle. Is a cross section having a circle, or is a fan-shaped cross section having a central angle that is generally a right angle.

In any case, as illustrated in FIG. 12 (a), the "non-circular cross section" refers to each cross section of the cone portion 174 of the hood 170 at at least one corner in the circumferential direction (eg, the cross section). A cross section that is partially non-circular so as to have a sudden change portion, eg, a right angle portion) 176, while having a partial circumferential portion 178 (eg, a semicircle, an arc, etc.) at at least one other location. ..

On the other hand, the "non-circular cross section" has a corner portion at at least one position in the circumferential direction in each cross section of the cone portion 174 of the hood 170, while the curved portion other than the arc is formed at at least one other location. For example, it may mean a cross section that is totally non-circular so as to have a partial ellipse, a partial oval, etc.).

Here, in each cross section, the number of corner portions 176 may be one, two, or three or more. Further, in each cross section, any of the two sides 179,179 constituting one corner portion 176 and abutting against each other may be a straight line, one may be a straight line, and the other may be a curved line. May also be a curve.

Further, in each cross section, the internal angle (angle of the inside corner) of the corner portion 176 may be a right angle, an acute angle, or an obtuse angle.

FIG. 12A shows the hood 170 in a front view, and FIG. 12B shows the base end portion 172 of the hood 170 in a cross-sectional view. The cross section of the cone portion 174 of the hood 170 at each axial position is changed from the one shown in FIG. It gradually changes to what is shown.

<Materials that make up the hood>

The hood 170 is made of a material having elasticity (property of being morphologically flexible so as to have high followability to the shape of the mating member and having shape restoration property) at least at the tip portion.

Thanks to its elasticity, the cleaning gun 110 is horizontal in at least a portion of the tip of the hood 170 (eg, in the example shown in FIG. 13C), as will be detailed later with reference to FIG. On the structure 12 when the side (tip edge) 179 extending to the surface and the side (tip edge) 179) extending vertically are in contact with the surface of the structure 12 and are moved along the surface to be swept. Obstacles (for example, the exposed bolt 190 in the example shown in FIG. 13) can be overcome by elastic deformation.

As a result, the operator does not need to change the distance between the cleaning gun 110 and the structure 12, that is, the injection distance D so as to escape the obstacle every time such an obstacle appears. If the injection distance D is maintained, the injection pressure does not fluctuate due to the change in the injection distance D, whereby the cleaning ability of the cleaning gun 110 is stably maintained during high-pressure cleaning.

As the material of the hood 170, an elastic body or an elastomer may be selected as a single material for the entire hood 170, or silicone (for example, rubber-like silicone) may be selected as the elastic body or the elastomer.

Further, the material of the hood 170 may have different materials for the tip portion of the hood 170 (the portion in contact with the structure 12) and the other portion. For example, the tip portion of the hood 170 is an elastic body. You may choose a composite material, such as the rest being rigid.

In the example of this composite material, it becomes easier to make a stronger connection with the tubular portion 114 and the bending rigidity of the hood 170 is improved, as a result, as compared with the case where the entire hood 170 is configured as an elastic body. Since the tip portion of the hood 170 bends from the rear end portion as a whole against the will of the operator, the possibility that it becomes difficult to aim the cleaning gun 110 is reduced.

<Visibility to the washed part of the hood>

It is desirable that the material of the hood 170 be selected so as to have at least partial light transmission at least at the tip of the hood 170.

Thanks to its light transmittance, the operator can use the hood 170 to position a momentary work target part, that is, a cleaning part (for example, the bolt exposed portion 190 in the example shown in FIG. 13) in the hood 170 during the work. The operator's line of sight optically penetrates the hood 170, thus allowing the operator to actually pass the cleaning site inside the hood 170, even though visual access to the cleaning site may be blocked. It is possible to visually check or monitor the behavior of the washing water colliding with the water in real time based on the shape of the washing part.

<Elastic overcoming characteristics of obstacles due to the hood>

FIG. 13A is a perspective view showing how the hood 170 fits geometrically to the inside corner 182 (cleaning surface to be cleaned) of the angle member 180 in the structure 12 as a work target. Has been done. Specifically, in this example, the two sides (two surfaces) 179 and 179 constituting the corner portion 184 of the cone portion 174 of the hood 170 are line-contacted or surfaced with the two surfaces of the corresponding inner corners 182, respectively. Contact.

In FIG. 3B, the cone portion 174 of the hood 170 is fastened to the angle member 180 in the process of the cleaning gun 110 being moved (following) along the inside corner 182 of the angle member 180 by the operator. A side view shows how the exposed portion 190 of the bolt is overcome by its own elastic deformation in chronological order.

Specifically, the cone portion 174 approaches the bolt exposed portion 190 on the side 179 of the cone portion 174 while contacting the upward surface of the inside corner 182. Subsequently, when the cone portion 174 comes into contact with the bolt exposed portion 190, the portion of the cone portion 74 that comes into contact with the bolt exposed portion 190 elastically gets over the bolt exposed portion 190. After that, when the cone portion 174 completes overcoming the bolt exposed portion 190, the cone portion 174 is restored to its original shape by its own elasticity.

As a result, the cleaning gun 110 can elastically overcome obstacles such as the bolt exposed portion 190 on its moving (strafing) path, so that the cleaning gun 110 can be used. It is possible to move along the inner corner 182 while performing high-pressure washing and peeling of the surface of the inner corner 182 while maintaining the height position of the inner corner 182. As a result, the burden on the operator who operates the cleaning gun 110 is reduced, thereby improving the work efficiency.

FIG. 3C shows a front view showing how the cone portion 174 of the hood 170 elastically deforms itself when it gets over the bolt exposed portion 190.

<Other effects due to the elasticity of the hood>

In this embodiment, as described above, the hood 170 has elasticity at least at its tip. As a result, the operator is in a state where the hood 170 is at least partially in contact with the surface of the structure 12 at its tip (eg, the hood 170 is almost entirely on the surface of the structure 12 around its tip. Contact, thereby the injection space in the hood 170 is largely shielded by the surface of the structure 12), without changing the overall position of the hood 170, the aiming orientation and aiming point of the cleaning gun 110. It is possible to change the position of, that is, to operate the angle and the position. This will be specifically described below.

The structure 12 may have a protrusion on its surface, and an example of the protrusion is the bolt described above with reference to FIG. When the protrusion is an object having a three-dimensional shape such as a bolt, the peripheral portion of the protrusion (for example, the outer peripheral surface of the protrusion and the protrusion of the surface of the structure 12) It may be necessary to perform high pressure cleaning of the annular region adjacent to the periphery, that is, for example, around the bolt.

If the hood 170 is a rigid body for high-pressure cleaning around the bolt, if the hood 170 comes into contact with the bolt or its peripheral members, the angle operation and the position operation of the cleaning gun 110 will be hindered. Therefore, the operator can revolve the momentary aim point of the cleaning gun 110 along the bolt peripheral portion so that the hood 170 does not come into contact with the structure 12, and the grip portion 130 of the cleaning gun 110 is the bolt center line. Complex work is required, such as operating the cleaning gun 110 so that it revolves around.

On the other hand, if the hood 170 has elasticity at least at the tip portion, even if the hood 170 comes into contact with a bolt or a peripheral member thereof, the angle operation and the position operation of the cleaning gun 110 are not hindered. Is revolving along the bolt circumference at the momentary target of the cleaning gun 110 so that the hood 170 remains in contact with the structure 12 (and as a result the injection distance D is also maintained). , Only a simple operation such as operating the cleaning gun 110 is required so that the cleaning gun 110 swings.

Therefore, according to the present embodiment, since the hood 170 has elasticity at least at the tip portion, the movement form thereof is simplified with respect to the operation required for the operator to perform high pressure cleaning of the bolt peripheral portion with the cleaning gun 110. , The effect that the burden on the worker is reduced and the work efficiency is improved can be obtained.

<Cleaning power characteristics of cleaning gun>

FIG. 14A conceptually shows the relationship between the amount of sprayed water and the impact pressure as a plurality of cleaning force characteristics of the cleaning gun 110, and FIG. 14B shows the injection angle θ. The relationship with the impact pressure is conceptually represented by a graph.

Here, the "spray water amount" means the amount of water (L / min) per unit time of the wash water jetted from the spray nozzle 154 of the wash gun 110. Further, the “impact pressure” means the pressure (kgf / cm ² ) generated on the surface of the structure 12 due to the collision of the washing water jetted from the washing gun 110 with the surface of the structure 12. Further, as illustrated in FIG. 11A, the “injection angle” means the apex angle θ of the fan-shaped spray pattern drawn by the cleaning water when the cleaning water is ejected from the injection nozzle 154.

As shown in FIGS. (A) and (b), in the cleaning gun 110, the larger the amount of sprayed water, the higher the impact pressure, and the smaller the injection angle θ, the higher the impact pressure.

FIG. 15 (a) conceptually shows the relationship between the injection pressure and the impact pressure as a plurality of different cleaning force characteristics of the cleaning gun 110, and FIG. 15 (b) shows the injection distance. The relationship between D and the impact pressure is conceptually represented by a graph.

Here, the "injection pressure" means the pressure generated in the cleaning water when the cleaning water is injected from the injection nozzle 154 (for example, the pressure in the injection nozzle 154). Further, the “injection distance” means the distance D between the injection nozzle 154 and the collision surface of the cleaning water, that is, the target cleaning surface, as illustrated in FIG. 11 (a).

As shown in FIGS. (A) and (b), in the cleaning gun 110, the higher the injection pressure, the higher the impact pressure, and the shorter the injection distance, the higher the impact pressure.

In FIG. 16, a plurality of places and a plurality of directions in which the cleaning water is scattered when the cleaning gun 110 sprays the cleaning water and collides with the cleaning surface in a state where the hood 170 is not attached are conceptually perspective views. It is represented in the figure.

If the amount of wash water that is scattered before the sprayed wash water collides with the wash surface is reduced, the amount of wash water that bounces off and scatters after the wash water hits the wash surface is also reduced, and is accompanied by this. The amount of the coating piece scattered in the scattered washing water is also reduced.

Therefore, in the present embodiment, the cleaning gun 110 is provided with a hood 170 for preventing the cleaning water from scattering laterally immediately after the injection during high-pressure cleaning.

Further, in the present embodiment, during the high pressure cleaning, the operator moves the cleaning gun 110 along the cleaning surface while contacting the cleaning surface at at least a part of the tip portion of the hood 170. That is, a contact mode in which the cleaning gun 110 is swept while in contact with the cleaning surface in the hood 170 is realized.

As a result, in the present embodiment, during high-pressure cleaning, the adhesion between the hood 170 and the angle member 180 as the cleaning portion is increased, and the unnecessary clearance between the two is reduced. Therefore, even if the washing water collides with an area laterally deviated from the regular washing area and tries to scatter to bounce off the area, the washing water to be scattered is captured by the hood 170.

Therefore, during high-pressure washing, in the contact mode, the washing water that bounces off the structure 12 and tries to scatter is captured by the hood 170, and as a result, the coating piece removed from the structure 12 by the collision with the washing water is removed. The amount of water carried and scattered by the bouncing wash water is also reduced. This effect is realized independently of the reduction in the amount of washed water scattered before the collision.

Further, in the present embodiment, during high-pressure cleaning, if the operator moves the cleaning gun 110 along the cleaning surface while contacting the cleaning surface with at least a part of the tip portion of the hood 170, the operation is performed. The actual injection distance D of the cleaning gun 110 is maintained substantially constant without the person being particularly aware of it. As a result, the injection pressure is also maintained substantially constant, thereby stabilizing the effect of the high pressure injection.

<New idea of jet scraper>

By the way, the simplest approach to increase the impact pressure of the cleaning gun 110 is to increase the amount of spray water of the cleaning gun 110. However, as the amount of jet water increases, the amount of water used by the cleaning gun 110 may increase and the work efficiency may decrease, and as the amount of jet water increases, the amount of washing water scattered and the coating pieces scattered during high-pressure washing. The amount may increase.

Therefore, in the present embodiment, in order to increase the impact pressure, an approach is taken in which the injection pressure is increased, the injection distance is shortened, and the injection angle is reduced while minimizing the amount of sprayed water.

Further, in the present embodiment, the injection (spraying) of the washing water is realized as a flat blowing (fan-shaped spraying), and the hole width W, which is the width dimension of the injection hole 156 of the injection nozzle 154, is minimized, thereby. The wash gun 110 is designed so that the wash water collides with the wash surface in an elongated, momentary wash area that is neither circular nor oval, thereby increasing the impact pressure while minimizing the amount of spray water.

Further, in the present embodiment, the cleaning gun 110 being sprayed is swept over the cleaning surface in a direction intersecting the cleaning area thereof, whereby cleaning having a generally one-dimensional shape is performed. The area is developed into a cleaning area having a two-dimensional or three-dimensional shape.

Therefore, the tip of the spray pattern from the cleaning gun 110 that collides with the cleaning surface is originally composed of a morphologically variable fluid, but is in a long and narrow instantaneous cleaning region and on the cleaning surface at high pressure. The unique cleaning method in this embodiment is referred to as a "jet scraper" because it has the same function as a scraper as a rigid body that does not change its shape as a result of collision.

In addition, this concept of jet scraper can be adopted in combination with a cleaning gun different from the cleaning gun 110, in combination with a completely different cleaning gun, or by itself. Is possible.

Further adding, in the above example, the cleaning gun 110 is used in a contact mode in which the hood 170 moves while in contact with the surface of the structure 12, but is non-contact moving without such contact. May be used in mode.

If the cleaning gun 110 is used in the contact mode, the effect of reducing the amount of scattered cleaning water immediately after injection can be obtained. On the other hand, if the cleaning gun 110 is used in the non-contact mode, the effect of reducing the amount of scattered cleaning water immediately after injection can be obtained.

For the same structure 12, all scheduled cleaning surfaces thereof may be cleaned only in contact mode, or all scheduled cleaning surfaces may be cleaned only in non-contact mode. Also, for the same structure 12, of all the planned cleaning surfaces of it, one area is cleaned in contact mode, another area is cleaned in non-contact mode, and so on, during a series of high pressure cleaning. The mode to be used may be switched between the contact mode and the non-contact mode alternately.

Against the background of the circumstances described above, for the cleaning gun 110, five main design variables are embodied as follows in order to realize the above-mentioned jet scraper.

Injection pressure: about 80-about 250 kgf / cm ² (for example, a high pressure injection region that does not reach an ultrahigh pressure region (eg, a region above 800 kgf / cm ² or 1,000 kgf / cm ² )).

Injection distance D: about 50-about 200 mm (eg, proximity injection area not exceeding 200 mm or 300 mm)

Injection angle θ: Approximately 10 to approximately 15 degrees (for example, a narrow angle injection region that does not exceed 20 degrees)

Jet water volume: Approximately 8-about 20 L (liter) / min (eg, low water volume injection region not exceeding 30 L / min, 40 L / min or 50 L / min)

Hole width (nozzle width) W: Approximately 0.2-about 0.6 mm (for example, a narrow injection region not exceeding 0.7 mm, 1 mm or 2 mm)

By selecting these values, the cleaning gun 110 realizes high pressure injection, proximity injection, narrow angle injection, small amount of water injection and narrow width injection.

In short, in the present embodiment, as a coating film removing high-pressure cleaning method for removing the existing coating film 14 from the surface of the structure 12 by injecting cleaning water at high pressure to clean the surface of the structure 12. Those having the following several steps are carried out.

High-pressure injection step: By operating the cleaning gun 110, cleaning water is injected at high pressure from an injection nozzle 154 for flat blowing in a fan-shaped spray pattern, whereby the cleaning water is sprayed from the structure 12 in an elongated instantaneous cleaning region. Collide with the surface.

Sweeping step: By sweeping the cleaning gun 110, the momentary cleaning area is moved in a direction intersecting it, thereby making the one-dimensional momentary cleaning area two-dimensional on the surface of the structure 12. Alternatively, it is developed in a three-dimensional cleaning area.

The present inventor uses a prototype of the cleaning gun 110 to physically remove the steel tower as an example of the structure 12 by the current high-pressure cleaning after the chemical removal of the coating film using a release agent. A test was conducted to confirm the effect of the high pressure washing.

As a result of the test, the present inventor confirmed the following multiple effects.

1. 1. Compared to the case where physical removal is performed manually or using a rotary tool, the work content is simplified and the work time is shortened, which reduces the number of required workers and reduces the load on each worker. ..

2. 2. Since the object applied to the structure 12 for physical removal is water, which is a flexible (highly followable to the mating object) fluid, the range of target parts that can be removed from the coating film is the range of each target part. The coating film was satisfactorily removed even in the narrowed portion, the complicated shape portion, and the difficult work portion of the structure 12, without being limited by the shape of the structure 12.

3. 3. The galvanized layer, which is the substrate of the structure 12, was not damaged, and therefore, the substrate of the structure 12 was well adjusted.

4. Since the release agent applied to the structure 12 prior to the high-pressure cleaning is also removed, it is possible to prevent the paint adhesion failure from occurring during the subsequent repainting of the structure 12 due to the residual amount of the release agent. Was done.

5. It is now possible to omit the cleaning work normally performed on the structure 12 prior to the repainting performed on the structure 12 after the coating film removing work is completed.

6. Prior to high-pressure cleaning, it is sufficient to unload the cleaning gun 110 and hose 122 to a high place, which is the work place of the tower, with the high-pressure source 124 installed on the ground, and as a result, it should be brought to that high place. The number and weight of tools and equipment has been reduced.

In addition, there is a trade-off between multiple effects when setting the injection pressure. That is, if the injection pressure is set high, the existing coating film 14 is more reliably removed from the surface of the structure 12, but the amount of scatter of the washing water and the coating film pieces tends to increase.

However, in the present embodiment, the high-pressure washing is not carried out independently on the surface of the structure 12, but prior to the washing, the existing coating film 14 is swelled and softened by applying a release agent. Therefore, it becomes easy to achieve the same coating film removing effect by high-pressure washing at a lower injection pressure.

Further, in the present embodiment, the cleaning gun 110 is used to inject cleaning water at an injection pressure that does not reach the ultrahigh pressure region to perform high pressure cleaning, but instead of this, the same cleaning is performed. The gun 110 may be used to perform high pressure cleaning by injecting cleaning water at an injection pressure belonging to an ultrahigh pressure region. In this sense, the term "high pressure" is interpreted herein to include the concept of "ultra-high pressure".

<Wastewater treatment unit>

FIG. 17A shows an example of the double sheet 202 as a part of the wastewater treatment unit 200 used for carrying out the wastewater treatment in FIG. 9 in a perspective view together with the scaffold 210. In (b), the water collecting sheet 222 of the double sheets 202 is shown in a side view.

As is well known, the scaffold 210 is suspended (supported) by a plurality of pillars 212 extending vertically from the ground as an example of a support surface (foundation surface) and the pillars 212 in a horizontally extending posture. ) A plurality of flooring materials 214 including a flooring material 214 that supports the worker's feet from below to enable the worker to perform high-pressure cleaning work using the cleaning gun 110, and a plurality of handrails (not shown). It is configured to have a member of.

Although not shown, the scaffold 210 is provided as a scaffold for a worker who cleans and peels off a structure 12 which is an example of an object to be cleaned, so that the scaffold 210 is usually on the ground and adjacent to the structure 12. Will be installed.

The double sheet 202 is installed on the scaffold 210 installed in the structure 12 for the worker at a position below the floor material 212 thereof. The double sheet 202 is composed of an upper filtration sheet 220 and a lower water collecting sheet 222, which are arranged so as to overlap each other in a plan view.

<Filtration sheet>

The filtration sheet 220 is configured to receive the wastewater and filter the wastewater to capture and recover the coating piece as a solid substance from the wastewater. The filtration sheet 220 is a flexible mesh sheet, and is suspended in a horizontally stretched and unfolded state by a plurality of handrails selected from the plurality of handrails. The filtration sheet 220 captures a part of the coating piece from the received wastewater by the mesh of the mesh sheet.

Specifically, from the mesh of the filtration sheet 220, the washing water (fresh water) of the wastewater and the plurality of coating pieces and debris initially mixed in the wastewater are smaller in size than the mesh. Leaks out.

The filtration by the filtration sheet 220 corresponds to the process called "first filtration" in the process diagram shown in FIG. Hazardous substances contained in the coating film pieces and debris that have passed through the filtration sheet 220 are captured and removed by the "second filtration" and the "third filtration" in the process chart.

<Water collection sheet>

The water collecting sheet 222 is configured to receive the wastewater after filtration by the filtration sheet 220 from the filtration sheet 220 and to guide the wastewater after filtration to the wastewater outlet 224 by utilizing its own weight. The water collecting sheet 222 is mainly composed of a flexible meshless sheet, and is suspended in a horizontally stretched and unfolded state by a plurality of handrails selected from the plurality of handrails. To.

The catchment sheet 222 generally forms a four-sided shape in the unfolded state, and is connected to the selected plurality of handrails 215 (see FIG. 17 (b)) on two or four sides thereof. The connection is performed so that a gap does not occur between each handrail 215 and the corresponding side of the water collecting sheet 222, whereby the wastewater is prevented from leaking from the gap. ..

As shown in FIG. 17B, in one example, a flexible elongated extension portion 223 is joined to the corresponding side of the water collecting sheet 222 in a posture extending parallel to the side (for example,). , Sewn). The extension 223 is wound around and connected to the corresponding handrail 215, whereby the catchment sheet 222 is suspended (suspended) by the scaffold 210.

The water collecting sheet 222 has a bottom portion 222b lower than the peripheral portion 222a in the central portion thereof, and is generally in the shape of a mortar as a whole. When the water collecting sheet 222 receives the wastewater from the filtration sheet 220 at the peripheral portion 222a, the wastewater descends along the peripheral portion 222a due to its own weight and eventually joins at the bottom portion 222b. A wastewater outlet 224 for sending wastewater downstream is installed at the bottom 222b.

<Coagulation tank and filtration basin>

FIG. 18 is a perspective view showing an example of the remaining portion of the wastewater treatment unit 200 shown in FIG.

The upper end of the connecting pipe 230, which generally extends in the vertical direction, is airtightly connected to the wastewater outlet 224 of the water collecting sheet 220 in a state of being fluidly communicated with the wastewater outlet 224. The lower end of the connecting pipe 230 is a drain pipe 232 that transports the waste water to a predetermined place located at the lower part of the scaffold 210 or away from the scaffold 210 and extends two-dimensionally or three-dimensionally. It is airtightly connected in a fluid communication state.

The drain pipe 232 has an outlet portion 234 in a vertically extending posture, for example. The wastewater discharged from the outlet portion 234 is sent into the coagulation tank 240. The coagulation tank 240 collects and stores the filtered wastewater discharged from the wastewater outlet 224.

In the coagulation tank 240, at least one of an adsorbent such as a coagulant, a heavy metal insoluble agent and an activated carbon powder is added to the wastewater contained therein that contains a harmful substance, whereby the coagulant tank 240 is added. , A predetermined harmful substance in the wastewater is aggregated. As a result, agglomerates (flocks) are generated in the wastewater.

Here, the "aggregator" is added to agglomerate a plurality of particles of a preselected hazardous substance by charge neutralization.

Further, the "heavy metal insolubilizer", for example, solidifies and insolubilizes the heavy metal in the coating piece in the wastewater in the in-situ, thereby suppressing the elution of the heavy metal into the washing water as a solvent in the wastewater. As a result, if the coating piece is captured, heavy metals are added together with it to promote capture without leakage.

Further, the "adsorbent such as activated carbon" is added to adsorb and capture heavy metal ions in wastewater by ion exchange. It is effective to configure the activated carbon as a plurality of particles or as a filter.

Regardless of which of the three types of heavy metal scavengers is used, heavy metals or objects containing heavy metals are trapped in the wastewater to form aggregates. In addition, two or more of these three types of heavy metal scavengers may be used in combination in the same wastewater. It is expected that the combined use will improve the capture effect and widen the types of substances to be captured.

Further, in the coagulation tank 240, the wastewater and the coagulant are agitated, whereby the amount of agglomerates as a precipitate increases. In the coagulation tank 240, the supernatant liquid and the precipitate are separated into upper and lower parts due to the difference in specific gravity between them.

Here, "aggregation, stirring and separation" corresponds to the process of "aggregation / stirring / separation" in the process diagram shown in FIG.

Further, in the coagulation tank 240, the wastewater is filtered by a filtration unit (not shown), whereby the precipitate is captured from the wastewater, and as a result, only the supernatant liquid is discharged from the coagulation tank 240. ..

Here, "filtration" corresponds to a process called "second filtration" in the process diagram shown in FIG.

The filtered wastewater (supernatant, treated water, etc.) discharged from the coagulation tank 240 is sent into the filtration basin 242. The filter basin 242 further filters the wastewater discharged from the coagulation tank 240, and separates the wastewater into a harmful substance as a solid substance and a wastewater after filtration from which the harmful substance has been removed.

Here, "filtration" corresponds to a process called "third filtration" in the process diagram shown in FIG.

FIG. 19 shows an example of the wastewater treatment shown in FIG. 9, which is described above, in a process diagram.

Of the wastewater treatments, steps S31-34 are described above.

Then, in step S35, the waste water in the filter basin 242 is separated into a harmful substance (sludge (precipitate)) as a solid substance and a waste water (liquid) after filtration from which the harmful substance has been removed.

Subsequently, in step S36, the above-mentioned filtered wastewater (liquid) is drained as detoxified, or in step S37, the detoxified wastewater is reused as new wash water. To do this, a submersible pump (eg, installed in the tank 125 (see FIG. 10)) (not shown) is used to recirculate into the tank 125.

Here, the submersible pump corresponds to a reuse means for reusing the detoxified wastewater discharged from the filtration basin 242 (an example of the "filtration unit") as new washing water.

The sludge is packed in the filtration bag 244. The filter bag 244 is a flexible bag having a filtering function (for example, a bag made by sewing a mesh sheet), which is configured to have a size that can be easily carried by an operator, for example. ..

Subsequently, in step S38, the sludge is drained using the filter bag 244, whereby the sludge passes through the mesh of the filter bag 244 and the moisture remaining in the filter bag 244 without passing through the sludge. It is separated into flocs.

The water may be treated in the same manner as the water that has passed through the filter basin 242, but may be drained as detoxified wastewater.

On the other hand, the wet floc is dehydrated by being dried together with the filtration bag 244 (naturally dried by leaving it to stand, or forcibly dried using a dryer or a heater in a drying chamber), whereby the wet floc becomes a dry floc. It is altered, resulting in a reduction in the amount of flocs remaining in the filter bag 244. At this time, dry flocs remain in the filtration bag 244.

Then, in step S39, the dried flocs are removed from the filter bag 244, and the dried flocs are disposed of as hazardous waste at a specific location.

Here, the filter bag 244 (another example of the "filter section") and the dryer or heater are both wet flocs that do not pass through the filter bag 244 and remain there and contain harmful substances. It corresponds to a weight reduction means of dehydrating and thereby reducing the amount of toxic waste to be discarded.

Here, "dehydration" is performed using the dryer or heater, but may be performed in place of or in addition to, for example, a centrifuge.

In addition, in this embodiment, an ion exchange fiber layer or an ion exchange resin layer is used as an optional element. When the filtered wastewater (in the process diagram shown in FIG. 19, the wastewater after the second filtration and / or the wastewater after the third filtration) passes through the layer, the layer passes heavy metal ions in the wastewater. Capture and collect.

The present inventor uses a prototype of the wastewater treatment unit 200 to confirm the effect of the wastewater treatment unit 200 in the case of performing the physical removal by the high-pressure washing this time after the chemical removal of the coating film using a release agent. Was tested.

As a result of the test, the present inventor confirmed the following multiple effects.

1. 1. The collection of coating pieces (peeling residue) generated from the structure 12 during high-pressure washing and the accumulation of coating pieces in a specific storage location became easy, and the man-hours required for the operator were reduced.

2. 2. Since the solid component is recovered and captured from the wastewater by a plurality of stepwise filtrations, the degree of detoxification of the wastewater is improved.

3. 3. Since the wastewater treatment unit 200 was installed at the site 210 before the release agent was applied to the structure 12, the release agent was applied on the surface of the structure 12 and then exposed to wind and rain. Even if the stripping agent that has been removed flows down from the structure 12, it is captured by the wastewater treatment unit 200, whereby the outflow of the stripping agent to the outside of the wastewater treatment unit 200 is prevented.

In addition, the above-mentioned wastewater treatment unit 200 may be adopted in combination with a cleaning gun different from the cleaning gun 110, in combination with a completely different cleaning gun, or independently. Is possible.

<Another coating film peeling method>

FIG. 20 shows another example of the coating film peeling method shown in FIG. 9 in a process diagram.

In the coating film peeling method shown in this process diagram, unlike the method shown in FIG. 9, high pressure cleaning is present in each of the two processes.

These steps are preliminary high pressure cleaning and production (full-scale, regular) high pressure cleaning, and the same wet peeling as shown in FIG. 9 is performed between these two types of high pressure cleaning. The actual high-pressure washing is carried out in the same manner as the high-pressure washing shown in FIG. After this production high pressure washing, the same wastewater treatment as shown in FIG. 9 is carried out.

Preliminary high pressure cleaning is performed on the existing coating film 14 before the release agent is applied onto the existing coating film 14. This preliminary high-pressure cleaning uses a cleaning gun 110 to inject cleaning water toward the existing coating film 14, thereby cleaning the surface of the existing coating film 14 to which the release agent is to be applied. At the same time, it is performed to peel off and remove the portion of the existing coating film 14 that has risen from the surface of the structure 12 before the application of the release agent.

As an effect of this pre-cleaning step, the amount and area of the existing coating film 14 adhering to the surface of the structure 12 prior to the application of the release agent are reduced as compared with the case where the pre-high pressure cleaning is not performed. After the implementation, the area of the surface of the structure 12 to which the release agent should be applied decreases, and thus the amount of the release agent required for the structure 12 decreases.

As a further effect of this pre-cleaning step, when washing water enters between a portion of the existing coating film 14 that is peeling off from the substrate of the structure 12 and the substrate, a release agent is subsequently applied to that portion. Then, the release agent easily adheres to the back surface of the existing coating film 14 that is about to be peeled off. As a result, the peeling of the existing coating film 14 by the release agent is promoted, and the effect of the release agent is increased.

To this effect, the cleaning gun 110 heats the cleaning water to a high temperature (for example, above 60 ° C., above 80 ° C., above 90 ° C., or reaches the boiling point) and injects it at high pressure onto the structure 12. If steam is generated from the sprayed wash water, it will be promoted. Specifically, since the gas called steam has higher followability to the mating member than the liquid, it enters between the portion of the existing coating film 14 that is peeling off from the substrate of the structure 12 and the substrate. And it becomes easy to penetrate.

As an example of the set value of the injection pressure of the cleaning gun 110, the first injection pressure in the preliminary high pressure cleaning is set to be lower than the second injection pressure in the actual high pressure cleaning, and specifically, the injection pressure is set to be lower than the second injection pressure in the actual high pressure cleaning. It is possible to set the second injection pressure to be less than about 50%, less than about 60%, less than about 70%, less than about 80% or less than about 90%.

[Third Embodiment]

Next, an exemplary third embodiment of the present invention will be described in detail with reference to the drawings. However, with respect to the elements common to the first and second embodiments, redundant description will be omitted by quoting using the same name or reference numeral, and only different elements will be described in detail.

FIG. 21 shows a high-pressure cleaning gun unit for removing a coating film (for example, step S2 in FIG. 9, step S103 in FIG. 20, etc.) used for performing high-pressure cleaning in the coating film peeling method according to the present embodiment. , FIG. 10, FIG. 12-the cleaning gun 110 shown in FIG. 13 and the like), the hood 300 is shown in a perspective view.

The cleaning gun unit 310 according to the present embodiment is configured to have a cleaning gun 110 that injects cleaning water from an injection nozzle at a high pressure, and a hood 300 that is attached to the cleaning gun 110 and generally has a hollow thin-walled conical shape. ..

The hood 300 covers the injection nozzle 156, extends from the injection nozzle 156 in a divergent manner in the injection direction, and has a base end portion 172 and a cone portion 174. The cone portion 174 is configured to have a main body portion 302 close to the cleaning gun 110 and a tip portion 304 away from the cleaning gun 110.

The hood 300 is an integrally molded product, so that the base end portion 172 and the cone portion 174 are both molded by the same member, and thus the main body portion 302 and the tip portion 304 are both molded by the same member. To.

Further, the hood 300 is molded from a material having elasticity and light transmission, whereby the main body portion 302 and the tip portion 304 both have elasticity and light transmission. Further, an example of the material is a transparent elastic material, and an example of the transparent elastic material is silicone.

Further, the hood 300 has a circular shape, an elliptical shape, an oval shape, or a non-circular shape so as to have a corner at at least one place in the circumferential direction of the hood as a cross-sectional shape. It is configured as follows.

In the illustrated example, the hood 300 is configured to form a non-circular shape so as to have a corner portion 176 at one position in the circumferential direction of the hood 300 as a cross-sectional shape. Specifically, the hood 300 is configured to form a non-circular shape (one closed frame) in which a corner portion 176 and a partial circumferential portion 178 are joined to each other at both ends thereof as a cross-sectional shape. There is.

The tip portion 304 is configured as an elastic annular thin-walled portion. The tip portion 304 has a plurality of movable pieces 320 due to a plurality of slits 310 extending from the tip surface 308 of the hood 300 in the direction generally opposite to the injection direction and extending to the boundary line between the tip portion 304 and the main body portion 302. It is divided into.

Each movable piece 320 has a thin plate shape and is supported by a main body portion 302 in a cantilever shape and elastically bendable. The shape of each movable piece 320 may have a plane, a curved surface, or two intersecting planes as long as it has a thin plate shape.

In any case, each movable piece 320 has a planar element, unlike a brush consisting of a plurality of linear elements, and as a result, each movable piece 320 also has a light transmission property. , The light transmission of the material is preserved to some extent so that the operator can pass through each movable piece 320 during the work and an obstacle (structure) on the inside of the hood 300, for example, the structure 12 (see FIG. 1). It is possible to visually check (such as a protrusion from the flat surface portion of 12).

Here, the "obstacle" is, for example, a bolt mounted on the structure 12 in which a nut is tightened on a portion exposed from the surface of the structure 12, as shown by reference numeral 190 in FIG. A nut exposed from the surface of the structure 12.

An example of the obstacle 190 is shown in FIG. In that example, the obstacle 190 is a bolt 322 mounted on the structure 12 in which a nut 326 is tightened to a bolt exposed portion 324 exposed from the surface of the structure 12.

On the other hand, when the brush is attached to the tip portion 304 of the hood 300 instead of each movable piece 320, even if the material constituting each linear element of the brush has light transmission, each linear element Does not have a planar element, which causes light scattering due to refraction and diffuse reflection of light, which hinders the light transmission of the material.

The plurality of slits 310 may be formed by performing post-processing using a cutter (not shown) on the molded product after the integrally molded product of the hood 300 is completed in a state where the slits 310 are not molded. Alternatively, it may be molded together with the integral molding of the hood 300 as a part of the target molding shape of the hood 300.

The corner portion 176 of the hood 300 can adopt various shapes as illustrated below from various viewpoints such as high flexibility of each movable piece 320.

In FIG. 22A, an example of the corner portion 176 of the hood 300 is partially shown as a corner portion 330 in a cross-sectional view, while in FIG. 22B, the corner portion 176 of the hood 300 is shown. Another example of is shown partially in cross section as a corner 340.

As shown in FIG. 22A, the corner portion 330 has a shape corresponding to the shape of the corner portion 176 shown in FIG. 21. Specifically, the corner portion 330 has a top movable piece (angle movable piece) 332 having a cross section generally forming an L shape. The top movable piece 332 is two movable pieces 320, which are adjacent to the top movable piece 332 on two virtual straight lines intersecting each other so as to form a curved roof in the cross section shown in FIG. 22 (a). Join the things you want to do to each other.

As shown in FIG. 22 (b), the corner portion 340 has a vertex movable piece 342 which is generally flat. The top movable piece 342 is two movable pieces 320, which are adjacent to each other on two virtual straight lines intersecting each other. Unlike the top movable piece 332, the top movable piece 342 generally has a flat plate shape, and therefore has higher bendability, that is, lower bending rigidity than the top movable piece 332.

In the example shown in the figure (a), substantially all the movable pieces 320 are configured to form a flat plate, whereas in the example shown in the figure (b), all of them are completely formed. The movable pieces 320 are all configured to form a flat plate.

As shown in FIG. 21, in the hood 300, there are two other parts similar to the corner portion 176. These two places are two places in the hood 300 where the two intersecting planes constituting the corner portion 176 and the partial circumferential surface 178 are joined to each other. As for the shapes of these two corners, the same idea inherent in the top movable piece 342 (or 344) is applied.

The cleaning gun 110 is stopped or moved with respect to the structure 12 in contact with the surface of the structure 12 at the tip surface 308 of one or more of the plurality of movable pieces 320 of the hood 300. The structure 12 can be washed under high pressure.

As shown in FIG. 23 (a) showing each movable piece 320 in the front view, the width dimension W of each movable piece 320 is a silhouette of the obstacle 190 obtained by projecting the obstacle 190 in the traveling direction of the cleaning gun 110. Greater than the width dimension of.

In the figure, the broken line represents the boundary line between the tip portion 304 and the main body portion 302 in the hood 300, and this line shows that each movable piece 320 of the hood 300 is elastic with respect to the main body portion 302. The part that functions as a hinge when bending is shown.

As shown in FIG. 23B, which shows each movable piece 320 in a side view, the length dimension L of each movable piece 320 is the obstacle 190 obtained by projecting the obstacle 190 in the traveling direction of the cleaning gun 110. Larger than the length dimension of the silhouette.

When the cleaning gun 110 is moved with respect to the structure 12 in contact with the surface of the structure 12 at the tip surface 308 of the one or more movable pieces 320, the cleaning gun 110 is moved to the structure 12 from the surface thereof. When the projecting obstacle 190 is present, one of the one or more movable pieces 320 facing the obstacle 190 can get over the obstacle 190 by its own elastic deformation.

FIG. 3C shows a process in which the cleaning gun unit 310 sweeps the target cleaning surface 350 while the tip or surface (downward surface, etc.) of one typical movable piece 320 is in sliding contact with the target cleaning surface 350 of the structure 12. It is a side view which shows the dynamic behavior when a movable piece 320 gets over an obstacle 190 in time series.

In the illustrated exemplary scenario, the movable piece 320 is in an inclined position from the neutral position shown in FIGS. (A) and (b) because it is pressed against the target cleaning surface 350. In this inclined posture, the tip or surface of the movable piece 320 moves while contacting the target cleaning surface 350.

In this process, at time t1, the movable piece 320 approaches the obstacle 190 from the side, and eventually the movable piece 320 comes into contact with the side surface of the obstacle 190, and the movable piece 320 receives a reaction force from the obstacle 190. .. Due to the reaction force, the movable piece 320 starts to elastically tilt with respect to the main body portion 302 in a direction of escaping from the obstacle 190.

Next, at time t2, the movable piece 320 elastically tilts further in a direction of escaping from the obstacle 190, whereby the forward surface of the movable piece 320 eventually comes into contact with the tip of the obstacle 190. After that, the movable piece 320 starts to move away from the center of the obstacle 190, and eventually the tip of the movable piece 320 separates from the tip of the obstacle 190.

Subsequently, at time t3, when the movable piece 320 ends contact with the obstacle 190, the movable piece 320 elastically recovers, whereby the movable piece 320 recovers to a state where its tip is in contact with the target cleaning surface 350.

Thus, according to the present embodiment, even if the obstacle 190 is present on the target cleaning surface 350 to be swept by the cleaning gun unit 310, the movable piece 320 has its own elastic deformation (elasticity of the hinge). By the deformation and the elastic deformation of the movable piece 320 itself), it is possible to overcome the obstacle 190 and restore the state of contact with the target cleaning surface 350 when the obstacle 190 is completed.

Therefore, according to the present embodiment, the operator maintains the hood 300 and the target cleaning surface 350 in close contact with each other without adjusting the height position of the cleaning gun unit 310 in response to the appearance of the obstacle 190. At the same time, the cleaning gun unit 310 can sweep the target cleaning surface 350.

As a result, according to the present embodiment, the amount of scattered washing water after injection and the amount of scattered coating piece separated from the substrate of the structure 12 due to collision with the washing water are reduced during high-pressure washing.

Although some embodiments of the present invention have been described above, the present invention can be implemented in other embodiments as illustrated below.

(1) Integrated type and split type

In the above-described embodiment, the tip portion 304 and the main body portion 302 are an integral type formed by the same member, whereas the tip portion 304 and the main body portion 302 may be a split type formed by different members. In the latter, the material used may be different between the tip portion 304 and the main body portion 302. For example, the tip portion 304 may be configured to have a lower bending rigidity than the main body portion 302 and to have a high flexibility.

Further, when the split type is adopted, for example, the tip portion 304 is formed as a flexible and linear band in which a plurality of slits 310 are formed from one side surface to the middle in the width direction, and the band is formed. Can be curved and mounted on the peripheral surface of the tip of the main body 302 on the other side surface thereof. In this case, the material used may be different between the tip portion 304 (the band) and the main body portion 302. For example, the main body portion 302 is formed of a rigid material, while the tip portion 304 is formed of a soft material. You may.

Further, when the split type is adopted, the main body portion 302 may be reused, while the tip portion 304 may be discarded as a consumable item for each operation.

(2) Variations in material selection

In the above-described embodiment, the hood 300 is made of silicone as a transparent elastic material, but other transparent elastic materials (for example, PE, PP) may be used, and an opaque or translucent elastic material may be used. You may use it. The elastic material includes synthetic resin and metal.

(3) Strafing in close contact with the entire circumference of the hood

Further, the cleaning gun unit 310 sweeps the target cleaning surface 350 of the structure 12 in a posture perpendicular to the target cleaning surface 350 and with the tip 304 of the hood 300 in contact with the target cleaning surface 350 almost all around. You may.

On the other hand, as illustrated in FIG. 24, the cleaning gun unit 310 may be swept in an inclined posture with respect to the target cleaning surface 350. In this case, the plurality of movable pieces 320 of the hood 300 are asymmetrical so that they are bent outward on the left side (contracted side) in the figure, whereas they are in a substantially neutral position on the right side (extended side). It is possible to be in a posture. This makes it easy to ensure that the tip 304 of the hood 300 is in contact with the target cleaning surface 350 all around, regardless of whether the cleaning gun unit 310 is in a right-angled posture or an inclined posture.

(4) Simultaneous strafing of the inner two or outer two sides of the angle material

25 (a) and 25 (b) show that the cleaning gun unit 310 simultaneously sweeps the inner two surfaces and the outer two surfaces of the angle material as the structure 12 as the target cleaning surface 350, respectively. It is shown.

In any of the sweeping scenarios, the structure 12 extends substantially vertically, and the sweeping is performed by the operator moving the cleaning gun unit 310 from top to bottom. In the sweeping state, the tip portion 304 of the hood 300 is in a posture in which the corner portion 176 is located on the upper side and the partial cylindrical surface 178 is located on the lower side, and is in contact with the inner two surfaces almost all around.

Specifically, the tip portion 304 has a plurality of corresponding movable pieces 320 bent outward at the corner portion 176 while maintaining a posture in which its two sides 179 and 179 extend substantially linearly, whereby the tip portion 304 is bent outward. The corner portion 176 is almost entirely in close contact with the inner two surfaces or the outer two surfaces. On the other hand, the tip portion 304 is deformed so as to imitate the inner two surfaces or the outer two surfaces on the partial cylindrical surface 178, and the corresponding plurality of movable pieces 320 are bent outward, whereby the corner portion 176 is formed. It adheres to the inner two surfaces or the outer two surfaces as a whole.

In the sweeping state, the corner portion 176 surely contacts the inner two surfaces or the outer two surfaces from the partial cylindrical surface 178, so that the droplets scattered from the cleaning water sprayed from the cleaning gun 110 during the sweeping contact with the corner portion 176. Leakage from between the inner two surfaces or the outer two surfaces is reliably suppressed. On the other hand, the cleaning water ejected from the cleaning gun 110 and rebounding from the inner two surfaces or the outer two surfaces is the partial cylindrical surface 178 and the inner two surfaces or the outer surface together with the coating piece removed from the structure 12. It leaks from the gap between the two surfaces and the gap between the movable pieces 320 and falls.

(5) Other variations of the method of setting the width dimension of the movable piece

In the example shown in FIG. 23A, the width dimension W of the movable piece 320 is set to be larger than the silhouette width dimension of the obstacle 190, but it may be set to be smaller than the silhouette width dimension. good. Specifically, for example, the dimension may be set within the range of 1/2 to 1/3 of the silhouette width dimension.

If the width dimension W of the movable piece 320 is set to be smaller than the silhouette width dimension of the obstacle 190 in this way, the movable piece 320 that bends from the neutral position to overcome the obstacle 190 and the movable piece 320 next to it. The gap between the object in the neutral position and the object in the neutral position will be closed by the obstacle 190 as much as possible.

On the other hand, when the width dimension W of the movable piece 320 is set to be larger than the silhouette width dimension of the obstacle 190, a plurality of continuous movable pieces 320 are placed from the neutral position in order to overcome the obstacle 190. If it is necessary to bend, there may be a movable piece 320 that bends wastefully even though it hardly touches the obstacle 190, in which case the useless movable piece 320 and the movable piece 320 next to it. However, the gap between the neutral position and the one in the neutral position will be present without being completely or almost blocked by the obstacle 190, and the droplets scattered from the washing water after spraying may leak from the gap. be.

(6) How to attach the hood

FIG. 26 shows a partial front sectional view showing an example of a method of attaching the hood 300 to the cleaning gun 110. In this example, the cleaning gun 110 has a tubular portion 114, and the tubular portion 114 is composed of a plurality of tubular members, and the tubular members are an example of a coupler 400 (a large diameter portion having a larger diameter than the tubular portion 114). It is connected by an example of a connector).

In the illustrated example, in the used state, the nozzle portion 150 having a diameter larger than that of the tubular portion 114 exists in the internal space of the hood 300, and the rearward surface of the nozzle portion 150 is the inner peripheral surface of the hood 300. Contact our bottom 420. As a result, the hood 300 is positioned at least axially with respect to the tubular portion 114.

Then, in order to attach the hood 300 to the tubular portion 114, the operator inserts the hood 300 from the rear end portion of the tubular portion 114 in the same posture as in the used state. At this time, the tubular portion 114 is inserted into the internal passage of the base end portion 172 of the hood 300.

After that, the operator advances the hood 300 in the axial direction with respect to the cylinder portion 114 so that the coupler 400 having a diameter larger than that of the cylinder portion 114 passes through the base end portion 172. At this time, it may be necessary for the proximal end portion 172 to overcome the coupler 400 due to its own elastic deformation.

Subsequently, the operator advances the hood 300 axially with respect to the tubular portion 114 until the rearward surface 410 of the nozzle portion 150 contacts the bottom portion 420 of the inner peripheral surface of the hood 300. This completes the work of attaching the hood 300.

(7) Bending of the hood

FIG. 27 shows an example of a method of manufacturing the hood 300 by bending, not by molding using a mold. It is a top view which shows an example of the sheet-shaped blank material 500 for the manufacturing method.

The blank material 500 can be punched once by punching (not shown). As a result, a plurality of punched products 510 (semi-finished products) are usually formed from one blank material 500. The punched product 510 has a shape when the hood 300 is unfolded in a plane, but the punched product 510 has two portions 520 that are bent and joined to both ends, and are added to the hood 300. The portions 520 are detachably or detachably coupled using fasteners such as hook-and-loop fasteners, snaps, buttons, magnets, hooks and the like.

The punched product 510 is bent into a cylindrical shape by an operator in a factory or a work site, and in that state, two portions 520 and 520 are joined by the fastener, whereby one hood 300 is completed.

(8) Hinge of movable piece

As illustrated in FIG. 28, a joint portion between the base end portion and the main body portion 302 of each movable piece 320, which functions as a hinge 550, has a flexural rigidity reduction portion (for example, a thin-walled portion, a perforation portion) on both sides or one side. Perforations, etc.)) are formed locally. As a result, the bendability of the hinge 550 is improved.

(9) Various effects due to a plurality of embodiments

In the above-mentioned second embodiment, the first feature that the cross section of the hood 300 is non-circular so as to have the corner portion 176 is adopted, whereas in the above-mentioned third embodiment, the first feature is adopted. The first feature and the second feature that the tip portion 304 of the hood 300 is configured as a plurality of movable pieces 320 are simultaneously adopted.

According to the first feature, for example, as described above with reference to FIG. 25, when the structure 12 is an angle material, the inner two surfaces or the outer two surfaces are prevented from scattering the washing water. The effect is that it becomes easy to sweep at the same time.

On the other hand, according to the second feature, the effect that the hood 300 can easily overcome the obstacle 190 while maintaining the close contact state between the hood 300 and the target cleaning surface 350 and the target cleaning surface. Even if the 350 is not flat, the effect that the hood 300 and the target cleaning surface 350 can be easily brought into close contact with each other can be obtained.

Further, according to the second feature, unlike the case where a brush is used instead of the movable piece 320, the movable piece 320 is flexible due to the coating film piece removed from the existing coating film 12 by the washing water after spraying. It is possible to reduce the inhibition of the property, that is, the flexibility, and as a result, it is possible to obtain the effect that the performance of the movable piece 320 to follow the target cleaning surface 350 in close contact is not deteriorated. When using a brush, coupled with the viscosity of the coating pieces, the gaps between the linear elements of the brush are narrow, so that the coating pieces are clogged and fixed between the elements, which makes the brush flexible. Easy to be hindered. Therefore, when a brush is used, the ability of the brush to follow the target cleaning surface 350 in close contact is deteriorated.

Then, the present invention may be carried out in a manner in which the above-mentioned first feature and the second feature are simultaneously adopted as in the above-mentioned third embodiment, or as in the above-mentioned second embodiment. In addition, it may be carried out in a mode in which only the first feature is adopted, or may be carried out in a mode in which only the second feature is adopted.

As described above, some of the exemplary embodiments of the present invention have been described in detail with reference to the drawings, but these are examples, and those skilled in the art including the embodiments described in the above [Summary of the invention] column. It is possible to carry out the present invention in other forms with various modifications and improvements based on knowledge.

In order to solve the above-mentioned second problem, according to the third aspect of the present invention, it is a coating film peeling method for peeling an existing coating film from a structure.
A wet peeling step of wetly stripping the existing coating film from the structure using a stripping agent.
After performing the wet peeling step, the process includes a high-pressure cleaning step of removing the existing coating film from the surface of the structure by injecting cleaning water at high pressure using a cleaning gun to clean the surface of the structure. The step of applying the release agent to the existing coating film for the purpose of using a high-pressure cleaning system for removing the coating film.
The spray nozzle of the wash gun is a flat blow nozzle, which allows the wash gun to spray wash water in a fan-shaped spray pattern, whereby the sprayed wash water is elongated. Provided is a coating film peeling method that collides with the surface of the structure in a momentary cleaning area.
In one example, the cleaning gun is configured to inject the cleaning water with an injection distance of about 50-about 200 mm, which is the distance from the injection nozzle to the target reach point on the structure. ..
Alternatively or additionally, in one example, the cleaning gun is configured to inject the cleaning water at an injection pressure of about 80-about 250 kgf / cm ² .
In place of or in addition to them, in one example, the cleaning gun is configured to inject the cleaning water at an injection rate of about 8-about 20 L / min.
According to the fourth aspect of the present invention, in order to solve the above-mentioned second problem (and / or the problem of improving the angle operability of the washing gun by the operator), the washing water is sprayed at a high pressure. A cleaning gun unit used to remove existing coatings from the surface of a structure by cleaning the surface of the structure.
A cleaning gun that injects cleaning water from an injection nozzle at high pressure,
With a hood that is attached to the cleaning gun and generally has a hollow thin conical shape
Including
The hood covers the injection nozzle and extends from the position of the injection nozzle in a generally divergent manner in the injection direction, and has a main body portion close to the cleaning gun and a tip portion away from the cleaning gun.
The main body is made of an elastic body.
The tip portion is configured such that a plurality of movable pieces extending in a direction generally parallel to the injection direction are arranged along the circumferential direction of the tip portion.
Each movable piece is provided with a high-pressure cleaning gun unit for removing a coating film, which is cantilevered and bendably supported by the main body portion.
According to the fifth aspect of the present invention, in order to solve the above-mentioned second problem (and / or the problem of improving the angle operability of the washing gun by the operator), the washing water is sprayed at a high pressure. A hood attached to a cleaning gun used to remove existing coatings from the surface of a structure by cleaning the surface of the structure.
Generally, it has a hollow thin-walled conical shape, covers the injection nozzle of the cleaning gun, and extends from the position of the injection nozzle in a generally divergent manner in the injection direction, and has a main body close to the cleaning gun and a tip away from the cleaning gun. Has a part and
The main body is made of an elastic body.
The tip portion is configured such that a plurality of movable pieces extending in a direction generally parallel to the injection direction are arranged along the circumferential direction of the tip portion.
Each movable piece is provided with a hood for a high-pressure washing gun for removing a coating film, which is cantilevered and bendably supported by the main body portion.

Claims (5)

A cleaning gun unit used to remove an existing coating film from the surface of a structure by injecting cleaning water at high pressure to clean the surface of the structure.
A cleaning gun that injects cleaning water from an injection nozzle at high pressure,
Attached to its cleaning gun, including a generally hollow thin-walled conical hood,
The hood covers the injection nozzle and extends divergently in the injection direction from the injection nozzle, and has a main body portion close to the cleaning gun and a tip portion away from the cleaning gun.
The tip portion is divided into a plurality of movable pieces by a plurality of slits extending from the tip surface of the hood in a direction generally opposite to the injection direction and extending to a boundary line between the tip portion and the main body portion.
Each movable piece is a high-pressure cleaning gun unit for removing a coating film, which has a thin plate shape and is supported by the main body in a cantilever shape and elastically bendable. The cleaning gun is stopped or moved with respect to the structure in contact with the surface of the structure in one or more of the movable pieces of the hood. The high-pressure cleaning gun unit for removing a coating film according to claim 1, which is capable of high-pressure cleaning. When the cleaning gun sweeps the surface of the structure in contact with the surface of the structure in the one or more movable pieces, the structure has an obstacle protruding from the surface of the structure. The high-pressure cleaning gun unit for removing a coating film according to claim 2, wherein the one or a plurality of movable pieces facing the obstacle can overcome the obstacle by its own elastic deformation. The high pressure for removing a coating film according to any one of claims 1 to 3, wherein the cleaning gun unit sweeps the surface of the structure in a state where the hood is in contact with the surface of the structure all around the tip portion. Cleaning gun unit. The high pressure for removing a coating film according to any one of claims 1 to 4, wherein the hood has a non-circular shape so as to have corners at at least one position in the circumferential direction of the hood. Cleaning gun unit.

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