JP7315268B1 - Wastewater treatment system with flocculation tank to which flocculant is added - Google Patents

Abstract

Kind Code: A1 In a technology for adding coagulant powder to waste water to coagulate target substances in the waste water for solid-liquid separation, a technique for stirring the coagulant powder is improved. A flocculation device (20) for flocculating target substances in wastewater includes a flocculation tank (40) and two stirring shafts (104, 104) arranged in parallel in a posture extending substantially vertically in the flocculation tank. . The stirring shafts respectively rotate two or two groups of stirring blades 106, 106 corresponding to each other in the same direction, thereby creating downward vortices in the wastewater with depressions opening to the liquid surface of the wastewater. . The flocculant powder is dumped into the depression of the vortex and then drawn by the vortex and allowed to settle towards the bottom 43 of the flocculating tank. [Selection drawing] Fig. 14

Description

The present invention relates to a technique for solid-liquid separation by adding a flocculant to washing water sprayed onto the surface of a structure and collected as wastewater after use to flocculate target substances in the wastewater, or a technique for adding powder to a liquid and stirring or mixing.

A wastewater treatment system is already known for recovering and treating washing water sprayed onto the surface of a structure as wastewater after its use (see Patent Documents 1 to 5, etc.).

This type of wastewater treatment system may be configured to include a flocculation device that flocculates target substances in the wastewater as flocculated flocs using a powdery or granular flocculant added to the wastewater for solid-liquid separation.

In that case, the flocculation device is specifically configured to have a flocculation tank, and a flocculant is added to the flocculation tank to flocculate the target substance in the wastewater for solid-liquid separation.

Throughout the application documents, the term "flocculant" is used in a broad sense, and the broad sense of "flocculant" selectively or comprehensively includes the narrow sense of "flocculant", "heavy metal insolubilizer" and "adsorbent such as activated carbon". Definitions of each of these terms are detailed below.

By the way, in specific cases, for example, when it is necessary to comply with the notification dated May 30, 2014 from the Ministry of Health, Labor and Welfare because it is confirmed that harmful substances such as lead are present in the existing paint film attached to the base of the structure, buildings (houses, buildings, etc.), steel towers that are long and thin structures constructed using a steel frame structure (e.g., power transmission towers, communication towers, etc.), civil engineering structures (bridges, etc.), ships, vehicles (automobiles, trains, etc.). , In order to repaint the surface of a structure such as an airplane or the structure, the existing coating film already applied to the surface is peeled off from the surface of the structure (substrate), and then a new paint is applied to the same surface of the structure.

Here, there are physical methods and chemical methods for removing the existing paint film.

In the physical method, workers use hand tools such as scrapers, electric rotary tools that rotate removal tools such as wire brushes using electric motors, air rotary tools that rotate similar removal tools using air motors, and peeling machines such as high-pressure water sprayers to remove existing paint films from structures. In contrast, the chemical method is a method of applying a release agent containing a chemical to an existing coating to dissolve or swell the existing coating, thereby peeling the existing coating from the structure. This method is also referred to as a wet coating removal method using a coating remover, ie, a wet stripping method.

When the wet stripping method is adopted, cleaning water is sprayed on the surface of the structure to clean the surface of the structure after the stripping agent is applied to the surface of the structure. Since the wash water may contain harmful substances, it is desirable to collect and treat it as waste water after use.

In short, the wet coating film stripping method described above includes a coating step of applying the stripping agent to the surface of the structure using an applicator such as a brush, a brush, a roller, a sprayer, an air spray gun, or an airless spray gun in order to strip the existing coating film from the surface of the structure using the stripping agent. The method further includes a cleaning step of spraying cleaning water onto the surface of the structure to clean the surface of the structure after the application. The method further includes a wastewater treatment step of recovering and treating the injected washing water as wastewater after its use.

For the wastewater treatment process, the wastewater is fed into a flocculating tank, and a powdery or granular flocculating agent is added to the wastewater so that target substances in the wastewater flocculate as flocculated flocs, and the flocculated flocs are separated from the wastewater.

Regarding this wastewater recovery treatment, there are several demands as follows from the viewpoint of environmental protection.

1. To detoxify the wastewater by separating and removing harmful substances (for example, substances contained in the existing coating film, substances contained in the plating layer of the base of the structure, and substances eluted in the washing water) mixed in the washing water after peeling and washing as wastewater (or wastewater).

2. To reuse the detoxified waste water as new washing water.

Against this background, prior to the present invention, the inventors of the present invention developed a technology for recovering and processing the washing water sprayed onto the surface of the structure after coating the release agent as waste water, and obtained Japanese Patent No. 6853599 for this technology. This patent publication is incorporated herein by reference as US Pat.

In addition, Patent Documents 2 to 5 disclose a technique of adding a flocculant to wastewater, agitating the flocculant using a stirrer, and treating target substances (e.g., harmful substances) in the wastewater (e.g., coagulation sedimentation treatment or coagulation sedimentation treatment by a coagulation tank, separation treatment by a separation tank, etc.). Each of these documents discloses one conventional example of a technique for dispersing powder in liquid.

Here, the stirrer includes, for example, a rotary type that rotates a stirring blade in the liquid and an air bubble type that injects air bubbles into the liquid using a pump to disperse the powder in the liquid. As a rotary agitator, there are an electric motor type using an electrically driven electric motor and an air driven type using an air motor driven by compressed air.

Further, Patent Document 6 discloses a technique of stirring a powdery material (powder, powder, etc.) or a granular material using a rotating sieve and adding it to an object in a dispersed manner. This document discloses a conventional example of a technique for dispersing powder in air.

Here, sieves include, for example, those used in a stationary state and those used in a dynamic state in which reciprocating rotation, vibration, or sound waves are generated.

Further, Patent Document 7 discloses a technique of stirring a liquid flocculating agent, ie, a flocculating agent, using a stirrer and adding it to industrial wastewater.

Specifically, the stirrer has a stirring shaft with a hollow housing and a plurality of stirring blades attached thereto. The hollow housing has an axial hole coaxial therewith that provides a passage for the condensed liquid agent.

The agitating shaft has a liquid inlet into which the condensing liquid is injected at the upper end of the axial hole, and further has a plurality of through holes radially penetrating the hollow housing arranged in a row in the downstream side thereof. The flocculant liquid agent injected into the stirring shaft from the liquid inlet is discharged into the industrial wastewater through the plurality of through holes during stirring.

Further, Patent Literature 8 discloses a technique of recovering, treating, and reusing washing water after use, which is sprayed onto the surface of a structure.

Specifically, this document discloses a flocculation device that performs sedimentation separation on the waste water using a flocculating agent. This document discloses a conventional example of the flocculation device, according to which the wastewater is injected into a filter cloth bag together with an aqueous flocculant solution, and the wastewater is subjected to sedimentation and separation. Thereafter, the wastewater is filtered by the filter cloth bag, and the treated water after filtration is pumped up using a pump instead of a drain and reused.

Japanese Patent No. 6853599 Japanese Patent Application Laid-Open No. 2006-0007176 JP 2020-0025919 A JP 2020-0065964 A Japanese Patent Application Laid-Open No. 2000-0325704 Japanese Utility Model Laid-Open No. 58-077638 Chinese Utility Model No. 210764511 Japanese Utility Model Laid-Open No. 7-24497

After that, the inventor conducted various tests and various researches and developments in order to improve the practicality of the developed wastewater treatment technology.

As a result, the inventors have found that it is important to satisfy the following requirements in order to improve the practicality of the wastewater treatment technology.

1. On-site wastewater treatment and portability of equipment for it

There are two types of wastewater treatment: a bring-in treatment method, in which wastewater is transported from the site where the wastewater is generated to a treatment facility in another location, and treated there, and an on-site treatment method, in which wastewater is treated on site.

On the other hand, it is important from the point of view of the worker and the person who owns or manages the structure to be worked on that the entire process from coating stripping (applying a stripping agent) to coating cleaning and wastewater treatment can be performed easily, quickly and efficiently on site.

Therefore, regarding the operation of wastewater treatment, there is a demand for transporting equipment for wastewater treatment to the site and performing wastewater treatment simply, quickly, and efficiently there.

2. Maximization of flocculating action of flocculant, i.e. optimization of dispersion state

In the operation of wastewater treatment, the flocculant is dispersed in the wastewater by agitating the wastewater after the flocculant is added to the wastewater.

By the way, in the field of wastewater treatment, flocculants are used for agitation of solid-liquid dispersion systems, since wastewater is liquid whereas flocculants are solid. In this case, the purpose of stirring the flocculant is, for example, mainly to move the particles, specifically to disperse the particles (prevent settling or floating, or disperse without forming lumps). Moderate dispersion of the particles means that the particles are uniformly agitated.

However, if the agitation of the flocculant is poor, the flocculant cannot be dispersed all over the wastewater, so it is difficult for the flocculant to fully exhibit its flocculating action, and a large amount of flocculant and work time may be wasted. When using a flocculant, it is important how to agitate the flocculant with a high agitation capacity (such as agitation efficiency) and how to disperse it throughout the wastewater.

Here, the "stirring capacity" or "stirring efficiency" is, for example, the total time (man-hours, etc.) required for uniform stirring of particles such as a flocculant (for example, achieving a target particle dispersity or particle density). It is quantified as a value obtained by dividing it by energy consumption, equipment scale, equipment cost, and the like.

Therefore, there is a demand for wastewater treatment operations to maximize flocculation by effectively agitating the flocculant so that it is completely dispersed throughout the wastewater.

3. Normalization of coating peeling work when reusing treated water

Wastewater after treatment is separated into treated water and flocculated flocs, and the treated water may be reused for coating peeling, which is an example of its application. For example, in that case, the presence of unintended residues in the treated water can interfere with coating stripping. Such residual substances are, for example, other substances added to the wastewater in order to suppress unintended phenomena during the agitation of the wastewater.

Therefore, in the case of waste water treatment, there is a demand to perform the paint film peeling work normally when the treated water generated by the treatment is reused for the paint film peeling work.

4. Prevention of clogging of the drain when the wastewater that has been subjected to the treatment of flocculation in the filter bag and filtration by the filter bag is discharged from the flocculation tank using the drain.

The wastewater treatment system may be configured to include a flocculating device for flocculating the wastewater using a flocculating agent. In this case, the flocculation device may be configured to include a flocculation tank capable of containing the wastewater and having a drain at the bottom of the flocculation tank, and a filter bag installed in the flocculation tank for filtering the wastewater injected into the filter bag while the wastewater is drained from the drain.

In embodiments where these possibilities are realized, the portion of the bottom of the filter bag facing the drain can either alone or in combination with agglomerated floc present in the filter bag cause clogging of the drain.

Therefore, in the work of wastewater treatment, there is a demand to prevent clogging of the drain at the bottom of the flocculation tank and to normally discharge the treated wastewater from the flocculation tank or transfer it from the flocculation tank to another downstream tank.

Some of the demands described above are not limited to the specific use of wastewater treatment, but also exist in other uses, for example, the use of adding powder to a liquid and stirring or mixing it.

Against the background of these circumstances, the present invention aims to improve the technique of stirring the flocculant and/or the technique of adding powder or granules containing powder or granules to a liquid and stirring or mixing the solid-liquid separation by adding a flocculant to the washing water that has been sprayed onto the surface of a structure and collected as wastewater after its use.

In order to solve the problem of improving the technique of agitating the flocculant, according to one aspect of the present invention, there is provided a wastewater treatment system for recovering and treating washing water sprayed onto the surface of a structure as wastewater after its use, comprising:
including a flocculation device for flocculating target substances in the wastewater for solid-liquid separation;
The flocculator is
a coagulation tank containing the wastewater;
an addition stirring unit that accommodates a flocculant outside the flocculation tank, adds the flocculant to the wastewater while dispersing it in the flocculation tank, and agitates the added flocculant in the flocculation tank;
a movement mechanism that enables the addition stirring unit to move relative to the flocculation tank in plan view, thereby enabling the flocculant to be sprayed into the wastewater;
and a stirrer for stirring the added flocculant by rotating a stirring blade in the flocculating tank.

To solve the same problem, according to another aspect of the present invention, there is provided a wastewater treatment system for recovering and treating washing water sprayed onto a surface of a structure as wastewater after its use, comprising:
a flocculating device for flocculating target substances in the wastewater as flocculated flocs using a powdery or granular flocculant added to the wastewater;
The flocculator is
a coagulation tank containing the wastewater;
two first stirring shafts arranged in parallel with a substantially vertically extending longitudinal gap in the flocculation tank;
a driving source that rotates the first stirring shafts so that the corresponding two or two groups of first stirring blades rotate in the same direction, thereby generating a downward vortex in or around a portion of the wastewater corresponding to the gap in the flocculation tank so as to have a depression that opens to the liquid surface of the wastewater;
A wastewater treatment system is provided, comprising: a dosing device that accommodates the flocculant and has a flocculant feeding start area facing the liquid surface, and capable of feeding the flocculant into the wastewater from the feeding start area;
In order to solve the same problem, according to still another aspect of the present invention, there is provided an apparatus for adding a powdery or granular flocculant to raw water in the flocculation tank to flocculate a target substance in the flocculation tank as flocculated flocs,
two first stirring shafts arranged in parallel with a substantially vertically extending longitudinal gap in the flocculation tank;
a driving source that rotates the first stirring shafts so that the corresponding two or two groups of first stirring blades rotate in the same direction, thereby generating a downward spiral in or around a portion of the raw water corresponding to the gap in the flocculation tank so as to have a depression that opens to the liquid surface of the raw water;
A flocculant addition device is provided that contains the flocculant and has a flocculant input start area facing the liquid surface, the flocculant being capable of inputting the flocculant into the raw water from the input start area, wherein the flocculant addition apparatus is arranged with respect to the flocculation tank so that the input start area corresponds to the depression generation area.
In order to solve the same problem, according to still another aspect of the present invention, there is provided a method of adding a powdery or granular flocculant to raw water in the flocculation tank to flocculate a target substance in the flocculation tank as flocculated flocs,
a rotation step of rotating two first stirring shafts arranged in parallel with a substantially vertically extending longitudinal gap in the flocculation tank so that the corresponding two or two groups of first stirring blades rotate in the same direction, thereby forming a downward spiral in or around a portion of the raw water in the flocculation tank corresponding to the gap so as to have a depression opening to the liquid surface of the raw water;
and a charging step of charging the flocculant toward the depressions of the spiral.
To solve the same problem, according to still another aspect of the present invention, there is provided a wastewater treatment system for recovering and treating washing water sprayed onto a surface of a structure as wastewater after its use, comprising:
a flocculation device that flocculates target substances in the wastewater as flocculated flocs using a powdery or granular flocculant added to the wastewater to separate solid and liquid;
The flocculator is
a coagulation tank containing the wastewater;
and two first stirring shafts arranged in parallel with a substantially vertically extending longitudinal gap in the flocculation tank, and
The first stirring shafts rotate the corresponding two or two groups of first stirring blades in the same direction, thereby generating a downward vortex in or around a portion of the waste water corresponding to the gap so as to have a depression opening to the liquid surface of the waste water;
A wastewater treatment system is provided in which the flocculant is dumped into the depression of the vortex and then drawn by the vortex and allowed to settle towards the bottom of the flocculation tank.

In order to solve the problem of improving the technique of adding a granular material to a liquid and stirring or mixing, according to one aspect of the present invention, there is provided a granular material stirring/mixing system for adding a granular material to a liquid and stirring or mixing,
a tank containing the liquid;
one or a plurality of agitating shafts arranged in close proximity in parallel in the tank, and
rotating the one or more stirring shafts to rotate the stirring blades coaxially therewith, thereby creating a downward vortex within the liquid contained in the vessel with a depression opening to the surface of the liquid;
The granular material is dropped toward the hollow of the spiral,
A granule agitating/mixing system is provided in which the dropped granules are drawn into the vortex and allowed to settle toward the bottom of the tank.

In order to solve the same problem, according to another aspect of the present invention, there is provided a powder stirring/mixing method for adding powder to a liquid and stirring or mixing,
a generating step of generating a downward vortex in the liquid contained in the tank so as to have a recess opening to the surface of the liquid by rotating one or more stirring shafts arranged in a substantially vertically extending posture or a plurality of stirring shafts arranged in close proximity in parallel in the tank containing the liquid and rotating the stirring blades coaxially therewith;
a dropping step of dropping the granular material toward the recess of the generated spiral;
and a sedimentation step of drawing the dropped granular material into the swirl and settling it toward the bottom of the tank.

According to one aspect of the present invention, in order to solve the problem of performing sedimentation separation in a filter bag in a flocculation tank for wastewater and improving the technology for filtering by the filter bag, according to one aspect of the present invention, there is provided a wastewater treatment system for recovering and treating washing water sprayed onto the surface of a structure as wastewater after its use,
a flocculation device for flocculating target substances in the wastewater using a flocculant to separate the wastewater into solid and liquid;
The flocculator is
a flocculation tank capable of containing said wastewater, having a drain at the bottom thereof;
a filter bag installed in the coagulation tank, which filters the wastewater in the process in which the wastewater injected into the filter bag is drained from the drain;
a spacer placed on the upper surface of the bottom of the flocculation tank, the spacer displacing at least a portion of the bottom of the filter bag facing the drain upward from the drain, thereby preventing clogging of the drain.

The present invention provides the following aspects. Each aspect is divided into sections, each section is numbered, and the numbers of other sections are referred to as necessary. This is to facilitate understanding of some of the technical features that the present invention can employ and combinations thereof, and should not be construed as limiting the technical features that the present invention can employ and combinations thereof to the following embodiments. That is, it should be construed that the technical features described in the present specification, which are not described in the following aspects, are appropriately extracted and employed as the technical features of the present invention.

Furthermore, stating each paragraph in the form of quoting the numbers of other paragraphs does not necessarily mean that the technical features stated in each paragraph are prevented from being separated from the technical features stated in other paragraphs, and should be construed as allowing the technical features stated in each paragraph to be made independent as appropriate according to their nature.

(1) A wastewater treatment system for recovering and treating washing water sprayed onto the surface of a structure as wastewater after its use, comprising:
a flocculation device that flocculates target substances in the wastewater as flocculated flocs using a powdery or granular flocculant added to the wastewater to separate solid and liquid;
The flocculator is
a flocculation tank for containing wastewater, wherein when the flocculant is added to the wastewater contained therein, the target substance is flocculated to form flocculated flocs;
an addition stirring unit that stores the flocculant outside the flocculation tank before adding it to the wastewater, disperses the flocculant that has been stored and adds it to the wastewater, thereby dispersing the flocculant in the air, stirring the added flocculant in the flocculation tank, thereby dispersing the flocculant in the liquid;
a moving mechanism that allows the addition stirring unit to move in plan view (e.g., translate horizontally) relative to the flocculation tank during the dispersed addition of the flocculant to the wastewater, thereby allowing the flocculant to be sprayed to the wastewater as the aerial dispersion of the flocculant again;
at least one stirrer provided as a part of the addition stirring unit and/or separately from the addition stirring unit, in the flocculation tank, stirring the added flocculant by rotating a stirring blade, thereby dispersing the flocculant in the liquid.

(2) The wastewater treatment system according to item (1), wherein the moving mechanism enables the addition stirring unit to move relative to the flocculating tank one-dimensionally or two-dimensionally in plan view during the addition of the flocculant to the wastewater.

(3) The addition stirring unit,
a frame;
a container mounted on the frame for dispersing and discharging the fed flocculant and adding it to the wastewater;
at least one first stirrer mounted on the frame and rotating at least one first stirring blade in order to stir the flocculant added to the wastewater in the flocculation tank without using air bubbles, thereby dispersing the flocculant in the liquid;
The wastewater treatment system according to item (1) or (2), in which the at least one first agitator disperses the flocculant in the liquid by both the rotation and the translational movement of the at least one first stirring blade in a state in which the addition stirring unit moves with respect to the flocculation tank.

(4) the container is a hopper that discharges the fed flocculant downward or sideways;
A wastewater treatment system according to clause (3), wherein the hopper optionally has a screen for manually or automatically dispersing the flocculant.

(5) The wastewater treatment system according to any one of (1) to (4), wherein the addition stirring unit is manually or automatically moved relative to the flocculation tank along a spiral or zigzag path.

(6) A movable range in which the addition stirring unit is movable and a non-movable range in which the addition stirring unit is not movable are assigned to the flocculation tank in plan view,
The wastewater treatment system further comprises at least one second agitator attached to the flocculation tank for rotating at least one second agitating blade to agitate the added flocculant without air bubbles, thereby dispersing the flocculant in liquid in addition to dispersing the flocculant in liquid by the at least one first agitator;
The at least one second agitator is mounted so that the at least one second agitating blade is located in the immovable range of the flocculation tank in plan view (1) to (5). The wastewater treatment system according to any one of items.

(7) The moving mechanism is
a first moving unit mounted on the tank body of the flocculation tank and movable in a first direction relative to the tank body;
a second moving unit mounted on the first moving unit and movable relative to the tank body in a second direction crossing the first direction;
A wastewater treatment system according to any one of items (1) to (6), wherein the addition stirring unit is attached to the second moving unit.

(8) The wastewater treatment system according to item (6), wherein the at least one first agitator and the at least one second agitator generate flow patterns different from each other by rotation of each agitating blade.

(9) The wastewater treatment system according to item (6), wherein the at least one first agitator and the at least one second agitator generate flow patterns that are different from each other in terms of axial flow or swirl flow due to the rotation of each agitating blade.

(10) The wastewater treatment system according to any one of items (3) to (9), wherein the at least one first agitator includes two first agitators extending downward facing each other across the vessel in a side view of the addition agitation unit.

(11) The wastewater treatment system according to (10), wherein the two first agitators rotate their respective first agitating blades in mutually opposite directions.

(12) said at least one second agitator comprises two second agitators;
The second stirrers are arranged to be staggered with respect to the flocculation tank in plan view, thereby cooperating with each other in the flocculation tank in plan view to generate a unidirectional circulating flow along the inner wall surface of the flocculation tank.

(13) The wastewater treatment system according to any one of items (3) to (12), wherein the at least one first agitator has a motor for rotating the first agitating blade, and the motor is driven by compressed air instead of electricity.

(14) The wastewater treatment system according to any one of items (6) to (11), wherein the at least one second agitator has a motor for rotating the second agitating blade, and the motor is driven by compressed air instead of electricity.

(15) Furthermore,
The wastewater treatment system according to any one of items (1) to (14), including a bag-shaped flexible floc trapping net arranged in the flocculation tank so as to partition the inner space into an outer space and an inner space, which is capable of trapping flocculated flocs generated in the wastewater while allowing water content in the wastewater to leak out as treated water, and which can selectively cause the flocculation tank to settle or float.

(16) The floc-trapping net is allowed to settle in the flocculation layer prior to addition of the flocculating agent to the wastewater, while the flocculation net is allowed to float out of the flocculation tank after the flocculation is generated, thereby separating the wastewater into treated water leaking out of the floc-trapping net and flocculated flocs remaining trapped in the floc-trapping net, whereby the floc-trapping net is used for both the flocculation stage and the separation stage. Wastewater treatment system.

(17) The wastewater treatment system according to item (15) or (16), wherein the addition stirring unit is moved in a range inside the floc capturing net in plan view.

(18) the addition stirring unit is equipped with at least one first stirrer;
The at least one first stirrer is arranged such that its first stirring blade is located inside the floc capturing net in plan view,
(17) Wastewater treatment system according to clause (17), wherein at least one second agitator is arranged such that its second agitator impeller is located outside said floc-trapping net in plan view.

(19) the addition agitation unit is equipped with at least one first agitator;
The at least one first stirrer is arranged so as to be positioned inside the floc capturing net in plan view,
A wastewater treatment system according to any one of paragraphs (15) to (18), wherein at least one second agitator is positioned inside or outside the floc-catching net in plan view.

(20) The wastewater treatment system according to any one of items (15) to (19), wherein the floc-trapping net is made of a flexible material and does not have self-retaining properties in its shape, but is at least locally reinforced by a three-dimensional frame so that its shape is substantially retained.

(21) The wastewater treatment system according to any one of items (15) to (20), wherein the floc-trapping net is attached to the frame so as to extend over at least the bottom surface and side surfaces of the frame, thereby forming a floc-trapping cage.

(22) The wastewater treatment system according to any one of items (1) to (21), wherein the flocculating device can be transported to the site where the wastewater is generated in its assembled state, or can be transported to the site and assembled at the site in an unassembled state.

(23) The addition stirring unit,
a frame;
a container mounted on the frame for dispersing and discharging the fed flocculant and adding it to the wastewater;
at least one non-motorized agitating member mounted to the frame and extending generally downwardly from the frame and submerged into the wastewater for agitating flocculant added to the wastewater in the flocculation tank without the use of air bubbles;
The wastewater treatment system according to any one of items (1) to (22), wherein the at least one agitating member is translated with respect to the flocculation tank in a state in which the addition agitating unit moves with respect to the flocculation tank, and the translational movement agitates the wastewater, thereby dispersing the flocculant in the liquid.

(24) A wastewater treatment system for recovering and treating washing water sprayed onto the surface of a structure as wastewater after its use, comprising:
a flocculation device that flocculates target substances in the wastewater as flocculated flocs using a powdery or granular flocculant added to the wastewater to separate solid and liquid;
The flocculator is
a flocculation tank for containing wastewater, wherein when the flocculant is added to the wastewater contained therein, the target substance is flocculated to form flocculated flocs;
A wastewater treatment system comprising: a bag-shaped flexible floc trapping net arranged in the flocculation tank so as to partition the interior space into an outer space and an inner space, capable of trapping flocculated flocs generated in the wastewater while allowing moisture in the wastewater to leak out as treated water, and selectively allowing the flocculation tank to sink and float.

(25) The floc-trapping net is allowed to settle in the flocculating layer prior to addition of the flocculating agent to the wastewater, while the flocculating net is allowed to float out of the flocculating tank after the formation of the flocculating flocs, thereby separating the wastewater into treated water leaking out of the floc-trapping net and flocculated flocs remaining trapped within the floc-trapping net, whereby the floc-trapping net is used for both the flocculation stage and the separation stage. Wastewater treatment system.

(26) A flocculation device for flocculating target substances in wastewater for solid-liquid separation,
a flocculation tank containing wastewater;
an addition stirring unit that accommodates a flocculant outside the flocculation tank, adds the flocculant to the wastewater while dispersing it in the flocculation tank, and agitates the added flocculant in the flocculation tank;
a movement mechanism that enables the addition stirring unit to move relative to the flocculation tank in plan view, thereby enabling the flocculant to be sprayed into the wastewater;
and a stirrer that stirs the added flocculant by rotating a stirring blade in the flocculation tank.

(27) The wastewater treatment system according to any one of (1) to (25), wherein the wastewater treatment system is used for recovering and treating the washing water sprayed onto the surface of the structure as wastewater after use to wash the surface of the structure after the remover has been applied to the surface of the structure in order to remove the existing paint film from the surface of the structure.

(31) A wastewater treatment system for recovering and treating washing water sprayed onto the surface of a structure as wastewater after its use, comprising:
a flocculation device for flocculating target substances in the wastewater using a flocculant to separate the wastewater into solid and liquid;
The flocculator is
a flocculation tank capable of containing said wastewater, having a drain at the bottom thereof;
a filter bag installed in the coagulation tank, which filters the wastewater in the process in which the wastewater injected into the filter bag is drained from the drain;
a spacer installed between the bottom of the filter bag and the drain, wherein a gap is formed between the bottom of the filter bag and the drain so that at least a liquid component of the wastewater can pass through the gap, thereby preventing clogging of the drain.

(32) The wastewater treatment system according to item (31), wherein the filter bag is a hard type that is self-supporting in terms of shape when it is left alone, or a soft type that is not self-supporting in terms of shape when it is left alone, and its shape is determined depending on the shape of the flocculation tank after it is installed in the flocculation tank.

(33) The wastewater treatment system according to item (31) or (32), wherein the filter bag is of a hard type that does not substantially deform even when an external force is applied to it when installed in the coagulation tank, or a soft type that substantially deforms plastically or elastically when an external force is applied to itself in the installed state.

(34) The bottom of the flocculating tank has a configuration in which, in a side view, the portion where the drain exists and the peripheral portion thereof have substantially the same height,
The wastewater treatment system according to any one of paragraphs (31) to (33), wherein the spacer is placed on the upper surface of the bottom of the coagulation tank, thereby pushing at least the portion of the bottom of the filter bag facing the drain upwardly away from the drain.

(35) The bottom of the flocculation tank has a form in which the portion where the drain exists is lower than the peripheral portion thereof when viewed from the side, and the portion where the drain exists and the peripheral portion are connected to each other by a tubular connecting portion extending in the height direction,
The wastewater treatment system according to any one of paragraphs (31) to (34), wherein the spacer is placed in the tubular connection, thereby pushing at least the portion of the bottom of the filter bag facing the drain upwardly away from the drain.

(36) The wastewater treatment system according to item (35), wherein the spacer uses a sheet-like wire mesh or a perforated panel and is configured to have a three-dimensional shape with a hollow inside.

(37) The spacer has a support surface that supports the filter bag from below at a position above the upper surface of the bottom of the flocculation tank in the entire length direction, or has a support surface that supports the filter bag from below at a position above other parts in the central portion of the length direction,
The wastewater treatment system according to any one of items (31) to (36), wherein the spacer is placed on the upper surface of the bottom of the flocculation tank so that the support surface faces the drain with a gap therebetween.

(38) The wastewater treatment system according to any one of items (31) to (37), wherein the spacer has a length dimension substantially equal to the length dimension of the bottom of the flocculation tank, thereby suppressing longitudinal displacement of the spacer during flow of the wastewater in the flocculation tank.

(39) The wastewater treatment system according to item (37), wherein the spacer has a length dimension shorter than the length dimension of the bottom of the flocculation tank, and the support surface has a length dimension that allows the support surface to be maintained in a state facing the drain with a gap even when the spacer is displaced in the length direction during the flow of the wastewater in the flocculation tank.

(40) The drain is arranged substantially in the center of the bottom of the aggregation tank in plan view,
The wastewater treatment system according to any one of items (31) to (39), wherein the spacer has a top surface at substantially the center of the spacer when viewed from the side.

(41) The spacer has a form in which the top surface and a pair of slopes sandwiching the top surface from both sides are arranged in a line in plan view,
The top surface and the pair of slopes are continuously connected without substantial steps in a side view,
Each slope, in a side view, is inclined in a direction to approach the bottom of the aggregation tank as it moves away from the top surface,
(40) The wastewater treatment system according to item (40), wherein the top surface faces the drain with a gap therebetween.

(42) The wastewater treatment system according to any one of (31) to (41), wherein the spacer is detachably installed with respect to the coagulation tank.

(43) Furthermore,
A separation device having a separation tank that separates the wastewater discharged from the coagulation tank into target substances of the same type as the target substances in the coagulation tank and treated water as wastewater after filtration from which the target substances have been removed,
The minimum trapped particle size of the filter bag is set to be larger than the minimum trapped particle size of the separation tank, whereby primary filtration is performed in the coagulation tank, and secondary filtration, which has a higher filtration accuracy than the primary filtration, is performed sequentially in the separation device. The wastewater treatment system according to any one of items (31) to (42).

(44) The wastewater treatment system according to any one of items (31) to (43), wherein the filter bag is joined to and integrated with the spacer at the bottom of the filter bag before being installed in the flocculation tank, so that when the filter bag is installed in the flocculation tank, the spacer moves integrally with the filter bag and remains on the upper surface of the bottom of the flocculation tank.

(45) The wastewater treatment system according to any one of items (31) to (44), wherein the coagulant is powdery, granular, or liquid.

(46) Furthermore,
an addition device for adding the flocculant toward the wastewater in the flocculation tank;
A wastewater treatment system according to any one of items (31) to (45), further comprising an agitating device for agitating the added flocculant in the flocculation tank.

(47) The flocculant is powdery or granular,
The addition device and the stirring device are
an addition stirring unit that accommodates the flocculant outside the flocculation tank, adds the flocculant that has been accommodated to the wastewater while dispersing it, and agitates the added flocculant in the flocculation tank;
a moving mechanism that allows the addition stirring unit to move two-dimensionally in a plan view relative to the flocculation tank, thereby enabling the flocculant to be sprayed into the wastewater;
(46) The wastewater treatment system according to item (46), comprising:

(48) A wastewater treatment system for recovering and treating wash water sprayed onto the surface of a structure as wastewater after its use, comprising:
A flocculation device for solid-liquid separation of the wastewater by flocculating target substances in the wastewater as flocs using a flocculant,
The flocculator is
a flocculation tank for containing the wastewater as it is injected, having a drain at the bottom thereof, the contained wastewater being allowed to drain through the drain by gravity;
a filter bag installed in the coagulation tank, which filters the wastewater by capturing solid components and passing liquid components out of the wastewater in the process in which the wastewater injected into the filter bag is drained from the drain;
A wastewater treatment system comprising: a spacer placed on the upper surface of the bottom of the flocculation tank, wherein at least a portion of the bottom of the filter bag facing the drain is lifted up from the upper surface of the bottom of the flocculation tank to float, thereby preventing the bottom of the filter bag from clogging the drain either alone or together with the flocculation floc during the discharge of wastewater from the flocculation tank.

(49) The wastewater treatment system according to any one of items (31) to (48), wherein the wastewater treatment system is used for recovering and treating the washing water sprayed on the surface of the structure as wastewater after use to wash the surface of the structure after the remover has been applied to the surface of the structure to remove the existing paint film from the surface of the structure.

(50) A sheet cleaning system for cleaning a used flexible sheet containing a liquid agent and/or a plurality of non-uniformly sized solids as waste, thereby allowing reuse or disposal of the used sheet, comprising:
a sheet guide mechanism for guiding the used sheet as a sheet to be cleaned in an unfolded state along a feeding path;
a first removal device that separates and removes larger ones of the plurality of solids from the surface of the sheet to be cleaned by blowing an air blow onto the surface of the sheet to be cleaned;
a second removing device that separates and removes the plurality of solids having a small size and the liquid agent from the sheet to be cleaned by enabling an operator to manually inject high-pressure cleaning water onto the surface of the sheet to be cleaned to wash the sheet, or by using a power source to automatically inject cleaning water at high pressure onto the surface of the sheet to be cleaned to wash the sheet with water;
The sheet guide mechanism is
a pair of guide wires installed on a stationary member and extending parallel to the feeding path on both sides of the sheet to be cleaned in the unfolded state;
a plurality of slide rings mounted on both sides of the sheet to be cleaned so as to be discretely aligned along each side, the slide rings moving integrally with the sheet to be cleaned along the feed path;
including
Each slide ring is slidably connected to the guide wire on the corresponding side of the pair of guide wires in the length direction thereof, whereby the sheet to be cleaned is suspended from the pair of guide wires in a state of being supported at both ends, and is slidable relative to the pair of guide wires along the feed path integrally with the plurality of slide rings.

(51) A wastewater treatment system for recovering and treating washing water sprayed onto the surface of a structure as wastewater after its use, comprising:
a flocculation device that flocculates target substances in the wastewater as flocculated flocs using a powdery or granular flocculant added to the wastewater to separate solid and liquid;
The flocculator is
a coagulation tank containing the wastewater;
and two first stirring shafts arranged in parallel with a substantially vertically extending longitudinal gap in the flocculation tank, and
The first stirring shafts rotate the corresponding two or two groups of first stirring blades in the same direction, thereby generating a downward vortex in or around a portion of the waste water corresponding to the gap so as to have a depression opening to the liquid surface of the waste water;
A wastewater treatment system in which the flocculant is dumped into the cavity of the vortex and then drawn by the vortex and allowed to settle towards the bottom of the flocculation tank.

(52) the flocculation device further includes at least one second stirring shaft attached to the flocculation tank;
(51) The wastewater treatment system of paragraph (51), wherein the at least one second agitating shaft rotates a corresponding at least one second agitator impeller, thereby dispersing flocculants entrained by the vortex within the wastewater.

(53) Two or two groups of first stirring blades corresponding to the two first stirring shafts, respectively, include an upper stirring blade arranged at a position close to the liquid surface of the wastewater in the flocculation tank,
The wastewater treatment system according to paragraph (51) or (52), wherein the upper stirring blade is attached to the corresponding stirring shaft so as to be axially position-adjustable in the assembled state of the stirring shaft, whereby the vertical distance from the liquid surface is adjustable.

(54) Two or two groups of first stirring blades corresponding to the two first stirring shafts, respectively, include a lower stirring blade arranged near the bottom of the aggregation tank,
The wastewater treatment system according to any one of items (51) to (53), wherein the lower agitating impeller is used for at least one of the use of assisting acceleration of the flocculant drawn in by the vortex to promote diffusion of the flocculant, and the use of promoting re-diffusion of sediment on the bottom of the flocculation tank containing the flocculant and the flocculated floc.

(55) The aggregation device further includes
a drain formed at the bottom of the aggregation tank;
a filter bag installed in the coagulation tank, which filters the wastewater in the process of draining the wastewater injected into the filter bag from the drain;
A wastewater treatment system according to any one of items (51) to (54), further comprising: a spacer installed between the bottom of the filter bag and the drain, wherein a gap is formed between the bottom of the filter bag and the drain so that at least the liquid component of the wastewater can pass through the gap, thereby preventing clogging of the drain.

(56) The wastewater treatment system according to any one of (51) to (55), wherein the wastewater treatment system is used for recovering and treating the washing water sprayed onto the surface of the structure as wastewater after use to wash the surface of the structure after the remover has been applied to the surface of the structure to remove the existing paint film from the surface of the structure.

(57) The wastewater treatment system of (56), wherein the target substance is selected from the group consisting of lead, chromium, asbestos and PCBs.

(58) A granule stirring/mixing system for adding and stirring or mixing granules to a liquid,
a tank containing the liquid;
one or a plurality of agitating shafts arranged in close proximity in parallel in the tank, and
rotating the one or more stirring shafts to rotate the stirring blades coaxially therewith, thereby creating a downward vortex within the liquid contained in the vessel with a depression opening to the surface of the liquid;
The granular material is dropped toward the hollow of the spiral,
A granule agitating/mixing system in which the dropped granules are entrained by the vortex and allowed to settle toward the bottom of the tank.

(59) A method of stirring/mixing powders and granules by adding powder to a liquid and stirring or mixing,
a generating step of generating a downward vortex in the liquid contained in the tank so as to have a recess opening to the surface of the liquid by rotating one or more stirring shafts arranged in a substantially vertically extending posture or a plurality of stirring shafts arranged in close proximity in parallel in the tank containing the liquid and rotating the stirring blades coaxially therewith;
a dropping step of dropping the granular material toward the recess of the generated spiral;
and a sedimentation step of drawing the dropped granular material into the swirl and settling it toward the bottom of the tank.

1 is a partially exploded perspective view of a flocculating device of a wastewater treatment system in accordance with a first exemplary embodiment of the present invention; FIG. FIG. 2 is a perspective view showing a flocculation tank, an addition stirring unit, a horizontal movement unit and a vertical movement unit extracted from the flocculation apparatus shown in FIG. FIG. 3 is an enlarged perspective view showing the addition stirring unit, the horizontal movement unit and the vertical movement unit shown in FIG. 2 together with the hopper and the first stirrer attached to the addition stirring unit. FIG. 4(a) is a partial cross-sectional view showing the flocculation tank, addition stirring unit, horizontal movement unit and vertical movement unit shown in FIG. 2, and FIG. 4(b) is a partial horizontal cross-sectional view showing the horizontal movement unit and vertical movement unit shown in FIG. FIG. 5(a) is a plan view for conceptually explaining an example of the flow pattern generated in the flocculation tank by the two second agitators, FIG. 5(b) is a side view for conceptually explaining an example of the flow pattern generated in the flocculation tank by the two first agitators, and FIG. 5(c) is a side view for conceptually explaining another example of the flow pattern generated in the flocculation tank by the two first agitators. FIG. 6 is a perspective view showing the flocculation apparatus shown in FIG. 1 having a flocculation tank, a drain pipe attached thereto, and a separation tank. FIG. 7 is a process diagram conceptually showing how the coagulation apparatus shown in FIG. 1 is assembled, installed, and dismantled and removed. FIG. 8 is a block diagram conceptually showing the process of solid-liquid separation of wastewater as raw water by the action of the flocculation device shown in FIG. FIG. 9 is a process diagram conceptually representing the assembly of the flocculation device shown in FIG. 1 and wastewater treatment using the flocculation device in chronological order. FIG. 10 is a partially exploded perspective view of a flocculating device of a wastewater treatment system in accordance with a second exemplary embodiment of the present invention; 11 is a plan view showing the flocculating tank of FIG. 10 with a floc trapping cage installed therein; FIG. FIG. 12 is a process diagram conceptually representing the assembly of the flocculation device shown in FIG. 10 and wastewater treatment using the flocculation device in chronological order. 13 is a perspective view showing an example of a clumped floc collecting sheet assembly that replaces the floc capturing cage shown in FIG. 10. FIG. FIG. 14(a) is a side view for conceptually explaining an example of a flow pattern generated in a flocculation tank by a pair of first stirrers arranged in parallel or facing each other and a pair of second stirrers arranged staggeredly in the first or second embodiment, and partially different from some examples shown in FIG. 5, and FIG. 14(b) is a plan view. FIGS. 15(a)-(c) show a plurality of photographs taken of an actual performance test of an example (prototype) using a flocculating tank equipped with a flocculating device according to the first or second embodiment. Specifically, FIG. ) shows a photograph of a flocculation device with each agitator being adjusted by an operator, and FIG. FIG. 16 is a cross-sectional front view of a flocculating device of a wastewater treatment system according to a third exemplary embodiment of the present invention, together with a separating device. 17(a) is a perspective view showing the spacer shown in FIG. 16 together with a waste water outlet, and FIG. 17(b) is a side cross-sectional view. FIG. 18 is a perspective view showing an example of the filter bag shown in FIG. 16 together with spacers and anti-floating devices. FIG. 19 is a process chart conceptually representing in chronological order a plurality of processes carried out using the wastewater treatment system shown in FIG. 20(a) is a side sectional view showing another example of the spacer shown in FIG. 16, (b) is a side sectional view showing still another example, (c) is a side sectional view showing still another example, and (d) is a side sectional view showing still another example. FIG. 21(a) is a partial cross-sectional side view and FIG. 21(b) is a partial cross-sectional plan view showing a sheet cleaning system according to a fourth exemplary embodiment of the present invention. FIG. 22 is a process chart schematically showing in chronological order the sheet cleaning method carried out using the sheet cleaning system shown in FIG. 21 together with other preceding processes and other subsequent processes. 23A and 23B are process diagrams showing the sheet cleaning method shown in FIG. 22 in time series. FIG. 24 is a diagram showing, in tabular form, correspondence relationships between a plurality of elements forming the sheet cleaning system shown in FIG. 21 and a plurality of steps forming the sheet cleaning method shown in FIG. FIG. 25(a) is a perspective view showing a sheet guide mechanism in the sheet cleaning system shown in FIG. 21, and FIG. 25(b) is a cross-sectional view. FIG. 26(a) is a perspective view showing the coating film piece recovery sheet assembly of the first removing device of the sheet cleaning system shown in FIG. FIG. 27(a) is a perspective view partially showing a first injection unit of the first removal device shown in FIG. 21, FIG. 27(b) is a side view partially showing the first injection unit, and FIG. 27(c) is a perspective view showing the joint shown in FIGS. 28 is a perspective view showing a cleaning water collecting sheet assembly of the second removing device of the sheet cleaning system shown in FIG. 21. FIG. 29 is a perspective view showing a working floor of the second removing device of the sheet washing system shown in FIG. 21; FIG. 30 is a front view showing the second removing device of the sheet washing system shown in FIG. 21 together with several coagulating filters attached thereto; FIG. FIG. 31(a) is a perspective view showing a sheet guide mechanism and a sheet feeding device of the sheet cleaning system according to the fifth exemplary embodiment of the present invention, and FIG. 31(b) is a longitudinal sectional view partially showing the sheet guide mechanism. FIG. 32(a) is a perspective view showing the injector moving device of the second removing device of the sheet cleaning system according to the fifth embodiment, FIG. 32(b) is a longitudinal sectional view showing the main part of the injector moving device, and FIG. 32(c) is a perspective view showing the injector driving device of the injector moving device shown in FIGS. FIG. 33 is a diagram showing, in tabular form, correspondence relationships between a plurality of steps constituting a sheet cleaning method according to the sixth exemplary embodiment of the present invention and a plurality of elements constituting a sheet cleaning system used to implement the sheet cleaning method. FIG. 34 is a perspective view showing an example of a filter sheet as an example of a used sheet to be cleaned by the sheet cleaning method according to some embodiments of the present invention.

[First embodiment]

A wastewater treatment system 10 for wet coating stripping (hereinafter simply referred to as "system") 10 according to a first exemplary embodiment of the present invention will now be described in detail with reference to the drawings.

As shown in FIG. 1, the system 10 is used to add a flocculating agent to the wastewater generated in the coating cleaning process during the wet coating stripping operation described above to flocculate target substances in the wastewater for solid-liquid separation.

More precisely, this system 10 is used to remove an existing paint film from the surface of a structure (steel tower, bridge, road, building, ship, vehicle, aircraft, etc.) using a stripping agent (liquid, fluid, foam, air bubble, etc.), which is applied to the surface of the structure and then sprayed onto the surface of the structure in order to clean the surface of the structure.

6, the system 10 generally comprises (a) a water collection device (not shown) for recovering the injected wash water as wastewater; (b) a flocculation device 20 having a flocculation tank for flocculating target substances in the wastewater as flocculation using a powdery or granular flocculant added to the wastewater; substance”) and filtered wastewater from which the harmful substances have been removed (hereinafter also referred to as “treated water”).

The treated water may, for example, be reused for the same or other industrial uses, or may be detoxified and discharged as normal sewage or industrial wastewater.

Hazardous substances as target substances to be removed from the wastewater are selected, for example, from the group consisting of lead, chromium, asbestos and PCBs, and are selected to contain all these constituents.

Among the water collecting device, the flocculating device 20 and the separating device 30, the flocculating device 20 and the separating device 30 located immediately downstream of the flocculation tank will be described in detail in this specification, but the water collecting device will be briefly conceptually described herein without referring to the drawings while omitting redundant description by citing Patent Document 1.

<Water collection device>

As shown in Patent Document 1, the water collecting device includes a double sheet installed at a position below the floor material of a scaffold installed on the structure (an example of the object to be cleaned) for workers to explain its configuration. The double sheet includes an upper filtration sheet and a lower catchment sheet, each arranged to overlap each other in plan view.

The filter sheet is configured to receive the wastewater and to filter the wastewater to remove solid coating particles from the wastewater. The water-collecting sheet is configured to receive filtered wastewater from the filter sheet and to guide the filtered wastewater to a wastewater outlet (for example, a through-hole formed in a portion of the water-collecting sheet that hangs most in the state of use (stretched state, unfolded state, stretched state, tension state, etc.)).

<Separation device 30>

In the flocculation device 20, the hazardous substances in the wastewater are flocculated at a target level, and when the flocculation stage is completed, the supernatant liquid (treated water) and the sediment (flocculated flocs of the hazardous substances) are separated vertically in the flocculation tank 40 due to the difference in specific gravity between them.

In one example, after the coagulation stage is completed, the wastewater in the coagulation tank 40 is filtered (for example, manually by an operator) using a filtering unit (not shown). Thereby, the sediments (hazardous substances, ie target substances) are captured in the wastewater, so that only the supernatant liquid in the wastewater is discharged from the flocculation tank 40 via the wastewater outlet 44 .

The discharged waste water is put into the separation tank 50 of the separator 30 . The separation tank 50 filters the introduced wastewater using a sieve 52, thereby separating the wastewater into hazardous substances as solids and filtered wastewater from which the hazardous substances have been removed, that is, treated water (treated water in the final process).

At the bottom of FIG. 6, an example of the separation tank 50 is conceptually shown in cross section. The separation tank 50 has a screen 52 (e.g., stationary or in a dynamic state with reciprocating rotation, vibration, or sound waves) 52. When the wastewater is introduced into the separation tank 50 so that it passes through the screen 52, harmful substances (e.g., finely divided flocs or fine particles) are captured by the screen 52, while moisture passes through the screen 52. The water that has passed through the sieve 52 is treated water.

As shown in the figure, a waste water outlet 44 is formed in the bottom of a sink 42 of a flocculation tank 40 (for example, when the bottom is mortar-shaped with a downwardly pointed bottom, the most drooping position of the bottom. A plate-like bottom, a bottom plate, a tank bottom, etc.) 43. A two-dimensionally or three-dimensionally bent drain pipe (or a flexible drain hose) 46 is connected to the waste water outlet 44. The drain pipe 46 is laid so that its outlet faces the opening of the separation tank 50 .

The sink 42 has a generally rectangular container shape, so that its outer wall consists of a front portion, a rear portion and a pair of side portions. Among them, the front part and the back part face each other in the longitudinal direction of the sink 42 , while the pair of side parts face each other in the width direction of the sink 42 .

<Aggregating device 20>

<Overall overview>

As shown in FIG. 1 , in this system 10 , the flocculation device 20 is generally configured to include a flocculation tank 40 , an addition stirring unit 60 , a horizontal movement unit 80 and a vertical movement unit 90 . The agglomerating device 20 further comprises two (more or less) first agitators 100 and two (more or less) second agitators 110 .

The aggregating device 20 is also an example of the above-mentioned "powder/granule agitating/mixing system" in which the powdery flocculant is an example of the "granules", the waste water is an example of the "liquid", and the aggregation tank 40 is an example of the "vessel".

<Basic specifications of stirrers 100 and 110>

These stirrers 100 and 110 have common basic specifications, and both are the above-mentioned rotary type and the above-mentioned air-driven type. Specifically, each of the stirrers 100 and 110 has a body portion 102 containing an air motor, as shown in FIG. The shaft 104 has, for example, a circular cross section and extends linearly, and its outer peripheral surface is a smooth surface without irregularities. Stirring blades (for example, paddle blades, inclined paddle blades, turbine blades, inclined turbine blades, propeller blades, etc.) 106 , 116 are attached to the tip (lower end) of the shaft 104 . When the agitator blades 106 are inclined paddle blades, inclined turbine blades or propeller blades, the agitator 100 produces a discharge flow parallel to its axial direction (see, for example, FIGS. 5(a) and 14(b)).

Since the stirrers 100 and 110 are air-driven, they are explosion-proof and do not cause ignition during agglomeration work, which improves the safety of workers.

<Technical Background for Developing Aggregation Device 20>

By the way, as a specification of the stirrer, there is also an air bubble type in addition to the rotary type. Prior to the present invention, the present inventors conducted tests to confirm the effectiveness of an air bubble stirrer (for example, high stirring capacity or high stirring efficiency). Specifically, the inventor confirmed the effectiveness of a method of agitating the coagulant in the waste water by jetting air bubbles from a nozzle into the waste water generated in the above-described coating film washing process during the wet coating stripping operation.

However, the stripping agent used in the wet coating stripping operation contains a surfactant as a dispersant. Therefore, the wastewater also contained the same surfactant. As a result, it was found that when air bubbles were jet-injected into the waste water to agitate the flocculant, the surfactant caused a violent bubbling phenomenon in the waste water (for example, a violent bubbling phenomenon such that the generated bubbles overflowed the flocculation tank).

In order to suppress the foaming phenomenon, the inventor has proposed and practiced adding an anti-foaming agent to the wastewater prior to injecting air bubbles into the wastewater. However, the inventor has found that the proposal has room for improvement.

Specifically, many of commonly available antifoaming agents contain silicone as a component. Therefore, even if the antifoaming agent is effective for the antifoaming effect of the waste water, the silicone component may not be completely removed from the final treated water and may remain.

If the silicone component remains in the final treated water and the treated water is used for a wet stripping operation on another structure (target to be stripped this time), the silicone component will adhere to the surface of the target to be stripped this time.

Therefore, the present inventor was concerned that if the surface to be peeled off was repainted while the silicone component had adhered to it, the paint would not adhere to the surface of the structure as expected, and a new problem of poor coating might occur.

Therefore, even if the air-bubble stirrer has a higher stirring capacity than the rotary stirrer, the inventor gave up the use of the air-bubble stirrer and decided to adopt the rotary stirrer in order to give priority to avoiding the above-mentioned new problems.

Furthermore, the present inventor studied how to effectively disperse the flocculant in order to compensate for the relative lack of stirring ability when using a rotary stirrer.

As a result of the research, the present inventor has realized the aerial dispersion (static aerial dispersion, primary aerial dispersion) at each momentary position (stationary state) of the addition stirring unit 60, additional aerial dispersion (aerial dispersion, dynamic aerial dispersion, secondary aerial dispersion) by two-dimensional movement of the addition agitating unit 60, and liquid dispersion by appropriately disposing a plurality of rotary agitators, and obtained the knowledge that it is important to maximize the effect.

Furthermore, the present inventors have found that it is also important to optimize the flow pattern synthetically generated by a plurality of stirrers in order to maximize the stirring effect of dispersion in liquid.

Therefore, the inventor created a technical idea for embodying these findings, as will be described in detail later.

<Structure and Effects of Aggregation Tank 40>

As shown in FIG. 6, the flocculation tank 40 has a stainless steel sink (tank body, housing, etc.) 42 which is generally container-shaped. The shape of the sink 42 is, for example, rectangular and forms a hexahedron with an open upper surface. The sink 42 is of a sealed type and has the function of containing liquid in an airtight manner. In this embodiment, the coagulation tank 40 and the sink 42 are separate structures, but they may be integral structures.

The flocculating tank 40 further has a frame 120 that supports the sink 42 . The frame 120 has a main body 122 that supports the sink 42, a plurality of legs 124 (e.g., four or fewer or more legs), a plurality of casters (feet, grounding portions, etc.) 126 corresponding to the legs 124, a drain pipe (drain pipe, etc.) 46, and a pair of stoppers (e.g., configured as angle members. See FIG. 2) 128, 128.

The body portion 122 is configured using a plurality of horizontal members (horizontal members and vertical members) and a plurality of vertical members. Of these horizontal members, upper surfaces of the horizontal members (pair of vertical members 48 , 48 ) that form a pair of long sides in plan view function as a pair of vertical rails 130 , 130 .

All of the plurality of legs 124 are in contact with a support surface (ground, leveled surface, floor surface, etc.) and extend upward from there to reach the main body 122 .

A plurality of casters 126 are attached to the lower ends of the corresponding legs 124, respectively. By rolling the casters 126, the operator can apply a lateral force to the coagulation tank 40 to freely steer the coagulation tank 40 and move it to an arbitrary target position.

The drain pipe 46 extends two-dimensionally or three-dimensionally from the waste water outlet 44 formed in the bottom portion 43 of the sink 42 to the separation tank 50 .

As shown in FIG. 2 , the pair of stoppers 128 , 128 abut against the addition stirring unit 60 to define the movement range of the addition stirring unit 60 along the pair of vertical rails 130 , 130 of the flocculation tank 40 .

The frame 120 is configured by an operator assembling a plurality of members using a tool. These members include multiple pipes (for example, square pipes), multiple angle members, multiple fittings, multiple fasteners, and the like.

An example of this flocculation device 20 is that the flocculation tank 40 has a horizontal dimension (width dimension) of about 800 to about 1100 mm, a vertical dimension (length dimension) of about 1700 to about 2000 mm, and a height dimension of about 400 to about 600 mm, which is smaller than those used for industrial wastewater.

Therefore, this flocculating device 20 can be transported to the site where the waste water is generated in its assembled state. Furthermore, the aggregation device 20 can be transported to the site before assembly, that is, in a state where the members are assembled, and assembled at the site.

<Addition stirring unit 60>

<Function>

As shown in FIGS. 1-4, the flocculation device 20 includes an addition stirring unit 60 . The addition stirring unit 60 accommodates the flocculant outside the flocculation tank 40 before adding it to the wastewater, and disperses and adds the accommodated flocculant to the wastewater, thereby dispersing the flocculant in the air.

Furthermore, the addition stirring unit 60 is moved two-dimensionally in a plan view relative to the flocculation tank 40 thanks to the laterally moving unit 80 and the longitudinally moving unit 90 during the dispersed addition of the flocculant to the wastewater.

Furthermore, the addition stirring unit 60 is equipped with the two first stirrers 100 described above, thereby rotating the two stirring blades 106, thereby stirring the added flocculant in the flocculation tank 40, thereby dispersing the flocculant in the liquid.

<Configuration>

The addition stirring unit 60 has a frame 140 . A hopper 142 is mounted on the frame 140 to disperse and discharge the introduced coagulant and add it to the wastewater. Additionally, two first agitators 100 are also mounted on the frame 140 . The first stirrers 100 rotate two first stirring blades 106 in order to stir the flocculant added to the wastewater in the flocculation tank 40 without using air bubbles.

However, in this embodiment, the frame 140 is shared with the frame of the laterally moving unit 80, so apparently the hopper 142 and the two first stirrers 100 are mounted on the frame of the laterally moving unit 80.

The hopper 142 is a container that discharges the fed flocculant downward or sideways. The hopper 142 has a screen 143 for manually or automatically dispersing the flocculant introduced.

By the way, Patent Literature 6 discloses an example of a hopper having a sieve for manually dispersing the charged flocculant. The hopper 142 in this embodiment is of the same type as that disclosed in the same document. Specifically, as illustrated in FIG. 3, when the operator grips and releases the trigger 144, the sieve 143 reciprocates, thereby dispersing the flocculant as powder in the air.

In this embodiment, an operator manually or manually actuates the sieve 143 as illustrated in FIG. Alternatively, the operator may activate the sieve 143 automatically, eg, by motor drive. The automatic control may be unattended, as programmed control, or manned, by wired or wireless remote control by an operator.

A holder 146 is attached to the frame 140 as illustrated in FIG. The holder 146 has a housing (for example, made by folding a stainless steel panel) surrounding the hopper 142 from its outer periphery, with relief holes provided on both sides for the handles 148 of the hopper 142 to escape. Thereby, the holder 146 holds the hopper 142 in a vertically detachable state by the operator.

The combined action of the addition stirring unit 60, the horizontal movement unit 80, and the vertical movement unit 90 causes dispersion addition of the flocculant from the hopper 142 (primary air dispersion), scattering of the flocculant by the two-dimensional movement (translational motion) (secondary air dispersion), stirring of the flocculant by the rotation of each first stirrer 100 (primary liquid dispersion), and stirring of the flocculant by the translational motion of each first stirrer 100 (secondary liquid dispersion). are performed in parallel.

FIG. 3 shows this addition stirring unit 60 more specifically. This addition agitator unit 60 has a holder 146 for holding the hopper 142 in place, a first through hole 150 formed in the frame 140 to match the discharge hole of the hopper 142 in its place, and two second through holes 152 formed in the frame 140 for mounting two first agitators 100.

Each agitator 100 is mounted using a corresponding second through hole 152 in its body portion 102 .

<Structure and Effects of Vertically Moving Unit 90>

As shown in FIGS. 1 to 4, particularly FIG. 2, the vertical movement unit 90 extends across the flocculation tank 40 and straddles the sink 42, and both ends thereof are supported by a pair of vertical rails 130, 130 in the flocculation tank 40.

As shown in FIG. 3, the longitudinal movement unit 90 has a longitudinal frame 91 with at least one wheel (such as a rolling element) 92 rotatably mounted at each end thereof, as shown in FIGS. 3 and 4(a). As shown in FIG. 4( a ), each wheel 92 rolls on the corresponding vertical rail 130 of the aggregation tank 40 to vertically move the vertical movement unit 90 .

In this embodiment, the vertical movement unit 90 is manually moved by the user (for example, by holding the handle 86 of the horizontal movement unit 80), but it may be self-propelled using an electric motor or the like.

As shown in FIG. 4(a), a frame 91 is fitted with a pair of guides 94, 94 spaced apart in the longitudinal direction (horizontal direction). These guides 94 , 94 engage the pair of vertical members 48 , 48 to guide the vertical movement unit 90 to move vertically without derailing from the vertical members 48 , 48 . In one example, during longitudinal movement, the outer surface of each guide 94 slides against the inner end surface of the corresponding longitudinal rail (angle member 48 ) 130 .

As shown in FIG. 3, the frame 91 has an elongated hole 96 extending through its thickness, and the elongated hole 96 extends along the trajectory drawn by the hopper 142 and each first agitator 100 as the addition agitation unit 60 laterally moves. The slot 96 permits coagulant distribution and passage of the shaft 104 and first stirring blade 106 of each first stirrer 100 at any position during its longitudinal movement.

As shown in FIG. 3 , opposite sides of the frame 91 across a slot 96 function as a pair of lateral rails 98 , 98 for the lateral movement unit 80 .

<Structure and Effects of Lateral Movement Unit 80>

As shown in FIGS. 1-4, and particularly FIG. 2, the lateral movement unit 80 is supported by a pair of lateral rails 98, 98 of the vertical movement unit 90 at both sides in the width direction of the frame 140 thereof.

The lateral movement unit 80 has a longitudinal frame 140, and at least one wheel (such as a rolling element) 84 is rotatably mounted on each side of the frame 140 in the width direction, as shown in FIGS. 3 and 4(b). As shown in FIG. 4(b), each wheel 84 rolls on the corresponding horizontal rail 98 of the vertical movement unit 90, thereby moving the horizontal movement unit 80 horizontally.

Lateral movement unit 80 further has a pair of handles 86, 86 at both longitudinal ends of frame 140 that can be grasped by a user.

In this embodiment, the lateral movement unit 80 is manually moved by the user (for example, by holding a pair of handles 86, 86), but it may be self-propelled using an electric motor or the like.

As shown in FIG. 4(b), the frame 140 is fitted with a pair of guides 88, 88 spaced apart in the width direction (longitudinal direction) thereof. These guides 88 , 88 are engaged with opposing inner wall surfaces of the slot 96 of the frame 91 of the vertical movement unit 90 to guide the lateral movement unit 80 to laterally move without derailing from the slot 96 . In one example, during lateral movement, the outer surface of each guide 88 slides against the opposing inner wall surface of slot 96 , ie, the inner end surface of the corresponding lateral rail 98 .

<Two-Dimensional Movement of Addition Stirring Unit 60>

In one example, the lateral movement unit 80 is manually or automatically moved relative to the aggregation tank 40 along a spiral or zigzag path integrally with the addition stirring unit 60 . As a result, the addition stirring unit 60 is moved two-dimensionally so that the flocculant is spread all over the surface of the wastewater in the flocculation tank 40 .

As shown in FIG. 2 and FIG. 11 for another embodiment, the flocculation tank 40 is assigned a movable range in which the addition stirring unit 60 can move two-dimensionally (“vertical movement range” in FIG. 2, and “longitudinal movement range” and “lateral movement range” in FIG. 11) and a non-movable range in which the addition stirring unit 60 is not movable.

In this embodiment, for convenience of explanation, it is possible to consider that the horizontal movement unit 80 constitutes an example of the above-mentioned "first movement unit", the vertical movement unit 90 constitutes an example of the above-mentioned "second movement unit", and the horizontal movement unit 80 and the vertical movement unit 90 together constitute an example of the above-mentioned "movement mechanism".

In this embodiment, the operator manually or manually operates the horizontal movement unit 80 and the vertical movement unit 90 (an example of the above-mentioned "movement mechanism" and hereinafter collectively referred to as "two-dimensional movement unit") as illustrated in FIG.

Alternatively, the operator may actuate the two-dimensional movement unit automatically, eg by motor drive. The automatic control may be unattended, as programmed control, or manned, by wired or wireless remote control by an operator.

<Two movable first stirrers 100>

As shown in FIG. 1 and FIGS. 5(b) and (c), each first agitator 100 is positioned relative to the agglomeration vessel 40 to provide, for example, center agitation or bottom agitation.

In one example, as shown in FIG. 5(b), both of the two first stirrers 100 rotate their respective first stirring blades 106 in the same direction.

As a result, the two first stirrers 100 cooperate with each other to form a first flow pattern, that is, a downward flow at any position of the stirrer 100, and eventually an upward flow on both the right and left inner wall surfaces of the aggregation tank 40, and at the position of the two first stirrers 100, generate a flow pattern in which the respective vertical water flows are parallel (in one vertical cross section, parallel flow, parallel flow, and symmetrical flow).

However, the illustrated flow pattern is drawn ignoring the influence of the water flow by the two second stirrers 110 for convenience of explanation.

In another example, as shown in FIG. 5(c), two first stirrers 100 rotate their respective first stirring blades 106 in opposite directions.

As a result, the two first agitators 100 cooperate with each other to form a second flow pattern, that is, a downward flow at the position of the agitator 100 on the left side in the figure, and eventually an upward flow along the left inner wall surface of the flocculation tank 40, while an upward flow at the position of the agitator 100 on the right side in the figure, and eventually a downward flow along the right inner wall surface of the flocculation tank 40. Generate a pattern (counter-flow, asymmetric flow in one vertical section).

However, the illustrated flow pattern is drawn ignoring the influence of the water flow by the two second stirrers 110 for convenience of explanation.

When these two flow patterns are compared from the viewpoint of whether or not the stirring efficiency of the flocculant is increased, the flow pattern shown in FIG.

In this embodiment, in order for the addition stirring unit 100 to achieve the stirring function, the rotation of the stirring blade 106 and the translational motion relative to the aggregation tank 40 are performed. As a result, the first sub-liquid dispersion by rotation of the stirring blade 106 and the second sub-liquid dispersion by stirring or agitating the waste water in the flocculation tank 40 as the shaft 104 as a stirring member capable of performing agitation independently of the stirring blade 106 during the translational motion are performed together.

In the example shown in FIG. 1, the two first stirrers 100, 100 are arranged side by side in the horizontal direction in a plan view, but instead of this, for example, they may be arranged in the vertical direction, or may be arranged in a direction inclined in both the horizontal and vertical directions.

<Two second stirrers 110 fixedly installed>

As shown in FIG. 1 and the plan view of FIG. As shown in FIG. 1 , each stirrer 110 is attached to the flocculation tank 40 by detachably attaching the body portion 112 thereof to a mounting bracket 160 attached to the frame 120 of the flocculation tank 40 .

The second agitators 110 rotate two second agitating blades 116 to agitate the flocculant added to the wastewater without using air bubbles, thereby dispersing the flocculant in the liquid additionally to the dispersion of the flocculant in the liquid by the two first agitators 100.

As shown in FIGS. 1 and 5(a), the two second stirrers 110 are arranged so as to be offset from each other in plan view with respect to the flocculation tank 40, and along the adjacent one of the plurality (for example, a pair) of the side portions (side portions extending parallel to the axial direction of each stirrer 110) of the sink 42.

Each second stirrer 110 achieves side stirring, for example, as shown in FIG. 5(a) in plan view.

In one example, as shown in FIG. 5( a ), the two second agitators 110 cooperate with each other in a third flow pattern, that is, a rightward discharge flow at the position of the agitator 110 on the left side in the figure, and eventually the discharged flow collides with the right inner wall surface of the flocculation tank 40 and changes its course so as to head toward the agitator 110 on the right side in the figure, while becoming a leftward discharge flow at the position of the agitator 110 on the right side. The discharged flow collides with the left inner wall surface of the flocculation tank 40 and changes its course upward toward the stirrer 110 on the left side in the figure (in one horizontal section, a unidirectional circulation flow along the inner wall surface of the sink 42, or a spiral water flow).

However, the illustrated flow pattern is drawn ignoring the influence of the water flow by the two first stirrers 100 for convenience of explanation.

Each secondary stirrer 110 is three-dimensionally arranged to achieve, for example, eccentric tilted stirring, as shown in FIG. Therefore, each second agitator 110 is expected to generate a flow pattern representing a combined water flow of the water flow generated by side agitation shown in FIG.

<Synthetic flow patterns generated by the first and second stirrers 110>

The above-mentioned third flow pattern is simultaneously generated in the sink 42 with the adopted one of the first and second flow patterns shown in FIGS. 5(b) and (c) respectively. These two different types of flow patterns, ie, two individual flow patterns, are mixed in the sink 42 into one combined flow pattern.

The composite flow pattern represents a more turbulent water flow than either of the two individual flow patterns. Therefore, the composite flow pattern may be more advantageous than either of the two individual flow patterns in that it contributes to increasing the agitating efficiency of the flocculant.

In one example, the first stirrer 100 and the second stirrer 110 generate flow patterns different from each other due to the rotation (rotation) of the stirring blades 106 and 116 .

In another example, the first stirrer 100 and the second stirrer 110 produce different flow patterns, whether axial flow or swirl flow, due to the rotation of the respective stirring blades 106,116.

As shown in FIG. 11 for describing another embodiment, the two second stirrers 110 are attached in a non-movable range of the aggregation tank 40 in plan view. As a result, the two first stirrers 100 mounted on the addition stirring unit 60 are prevented from interfering with the two second stirrers 110 fixedly installed in the aggregation tank 40 at any two-dimensional position during the movement of the addition stirring unit 60.

<Definition of flocculant>

As mentioned above, the term "flocculant" is used here to mean "flocculant" in a broad sense. Therefore, the broadly defined "flocculating agent" can be equivalently replaced with terms such as "liquid target substance scavenger", "hazardous substance scavenger", and "heavy metal scavenger". The broadly defined "flocculants" selectively or comprehensively include narrowly defined "flocculants", "heavy metal insolubilizers" and "adsorbents such as activated carbon".

For example, a narrowly defined "flocculant" is added to flocculate a plurality of particles of preselected hazardous substances by charge neutralization.

In addition, the "heavy metal insolubilizer" is added to, for example, solidify and insolubilize the heavy metals in the coating film pieces in the waste water in situ, thereby suppressing the elution of the heavy metals into the washing water as the solvent in the waste water, and as a result, if the coating film pieces are captured, they are also added to promote the capture of the heavy metals without leakage.

In addition, an "adsorbent such as activated carbon" is added to adsorb and capture heavy metal ions in wastewater by ion exchange. Advantageously, the activated carbon is configured as a plurality of particles or configured as a filter.

The use of any of these three heavy metal scavengers will trap heavy metals or heavy metal-containing objects in the wastewater to form agglomerates. Also, two or more of these three types of heavy metal scavengers may be used in combination in the same wastewater. Combined use is expected to improve the capture effect and broaden the types of substances to be captured.

<Test results of stirring work>

Using the system 10 shown in FIG. 1, the inventor added a flocculant to the wastewater in the flocculation tank 40 and stirred the wastewater.

When the stirrers 100 and 110 were suddenly rotated at a high speed while the wastewater was stationary, air was unexpectedly mixed into the wastewater and air bubbles were generated. In order to prevent this, the present inventor gradually accelerated the rotational speed of the stirrers 100, 110 so as to synchronize with the water flow generated in the wastewater, thereby effectively suppressing the generation of air bubbles in the wastewater.

When the coagulant is sprayed from the addition stirring unit 60 in a state where the water flow (e.g., turbulent flow) synchronized with the stirrers 100 and 110 is generated in the wastewater, the coagulant is smoothly sucked into the swirl in the wastewater. This distributed the flocculant throughout the wastewater.

In a state in which turbulent flow was generated in the drainage, even if the agitators 100 and 110 were stopped, the turbulent flow continued due to inertia, and the agitators 100 and 110 did not substantially interfere with this.

In this test, only about 10 minutes elapsed from the start of sprinkling of the flocculant into the wastewater to the flocculation of substantially all of the target substances in the wastewater into flocs. The reason why the flocculation work was completed in such a relatively short time is presumed that the flocculant effectively contacted and acted on all the target substances in the wastewater without the flocculant dispersing throughout the wastewater and each part of the flocculant being clustered wastefully.

<Example of assembly installation and dismantling removal of the aggregation device 20>

FIG. 7 conceptually shows how assembly and installation and disassembly and removal of the aggregation device 20 are handled in a process diagram.

First, in step S11, the operator himself/herself or an entrusted third party transports the flocculating device 20 in a state before assembly, that is, in a state in which a plurality of parts thereof are assembled, from the home base to a destination site, that is, a place where the above-mentioned wet coating film stripping operation is scheduled to be performed, using transportation means such as a truck.

Next, in step S12, after arriving at the site, the operator assembles the plurality of parts at the site to complete the aggregation device 20, and then moves the aggregation device 20 to a required position and installs it.

Subsequently, in step S13, an operator or another person performs the above-described wet coating stripping operation at the site, and in the process, uses the flocculation device 20 to treat the waste water generated in the coating cleaning step.

Thereafter, in step S14, after the series of steps are completed, the operator dismantles the aggregation device 20 into a plurality of parts and removes them from the site.

Finally, in step S15, the operator or another person returns the collection of parts to the home base using a transport means such as a truck.

<Example of transition of wastewater>

FIG. 8 is a block diagram conceptually showing the process of solid-liquid separation of waste water as raw water by the action of the flocculation device 20 .

First, in the aggregation stage, the operator uses the aggregation device 20 to add (spray) a coagulant to waste water as raw water.

Next, in the separation stage, an operator solid-liquid separates raw water into treated water as liquid and aggregated flocs as solids.

This solid-liquid separation is performed, for example, in two stages.

Specifically, in the first stage, the worker separates and collects the flocculated flocs (hazardous substances) from the flocculation tank 40 (for example, the worker scoops them up with a net (e.g., in a subdivided collection method)), and then the worker discharges the wastewater from the wastewater outlet 44 of the flocculation tank 40 as completely or incomplete treated water.

In the second stage, the operator feeds the discharged wastewater (with large-sized hazardous particles removed) to the separation tank 50 . In the separation tank 50 , the remaining pollutant particles are captured by a sieve 52 . The operator may reuse the wastewater that passes through the screen 52 as treated water, for example, in another wet paint stripping operation.

However, this solid-liquid separation may be performed in one step, or may be performed through three or more steps. Alternatively, the above-described first step may be omitted, and solid-liquid separation of the waste liquid may be performed at once by the same method as in the above-described second step.

<Example of wastewater treatment work>

FIG. 9 conceptually shows the assembly of the flocculation device 20 and the wastewater treatment using the flocculation device 20 in a time-series process chart.

First, in step S21, a worker assembles the aggregation tank 40 using the plurality of parts described above at the site or at the home base.

Next, in step S22, the operator installs the vertically movable unit 90 (which is, for example, carried into the site or home base in a completed state) on the flocculation tank 40 using a pair of guides 94,94.

Subsequently, in step S23, the worker installs the laterally moving unit 80 (which is, for example, carried into the site or home base in a completed state) on the longitudinally moving unit 90 using the pair of guides 88,88.

Thereafter, in step S24, the operator mounts the holder 146 on the frame 140 of the addition stirring unit 60, which is also the frame 140 of the lateral movement unit 80, loads the hopper 142 on the holder 146, and mounts the two first stirrers 100 on the frame 140. As a result, the addition stirring unit 60 is integrated with the lateral movement unit 80 .

Subsequently, in step S25, the operator installs the two second stirrers 110 on the frame 120 (front and back portions described above) of the flocculation tank 40 in an inclined state using the mounting brackets 160 .

After that, in step S26, the operator puts the waste water into the sink 42 of the coagulation tank 40 as raw water. As a result, both the two first agitators 100 and the two second agitators 110 are submerged in the wastewater with their respective agitator blades 106, 116 rotating.

Subsequently, in step S27, the operator puts the flocculant into the hopper 142, and while the hopper 142 disperses and adds the flocculant to the wastewater, the two first stirrers 100 rotate to agitate the flocculant. Here, "dispersed addition" corresponds to primary dispersion in air, and "stirring by rotation" corresponds to primary dispersion in liquid.

Also, in step S28, the operator uses the handle 86 of the addition stirring unit 60 to two-dimensionally move it above the aggregation tank 40. As shown in FIG. A flocculant is thereby dispersed over the surface of the wastewater. Here, "dispersion" corresponds to secondary aerial dispersion.

In step S29, the two first stirrers 100 are rotated and two-dimensionally moved (translated) to stir the flocculant. Here, "translational agitation" corresponds to secondary liquid dispersion.

Further, in step S30, the coagulant is stirred by the rotation of the two second stirrers 110. As shown in FIG. Here, "stirring due to rotation" corresponds to tertiary liquid dispersion.

These steps S27-S30 are performed in parallel rather than sequentially.

Thereafter, in step S31, the operator separates the raw water into treated water and aggregated flocs.

Subsequently, in step S32, the operator directly discharges the treated water from the separation tank 50 or from the aggregation tank 40.

In order to disperse the flocculant from the hopper 142 to the flocculation tank 40, the operator moves the addition stirring unit 60 two-dimensionally with one hand, and at the same time grips the handle 148 of the hopper 142 with the other hand.

If the operator continuously operates the trigger 144, the flocculant is continuously sprayed while the addition stirring unit 60 is moving. On the other hand, if the trigger 144 is operated intermittently, the flocculant is intermittently dispersed (while leaving a section where it is not sprayed) while the addition stirring unit 60 is moving.

As a result, the coagulant is finally spread as evenly as possible over the entire surface of the wastewater in the coagulation tank 40 that is within the movable range.

[Second embodiment]

A second exemplary embodiment of the present invention will now be described. However, elements common to those of the first embodiment will be referred to with the same reference numerals to omit redundant description, and only different elements will be described in detail.

FIG. 10 shows a partially exploded perspective view of the flocculating device 210 of the wastewater treatment system 200 according to the present embodiment.

This aggregation device 210 has components common to the aggregation device 20 in the first embodiment and novel components not present in the aggregation device 20 . The novel component is, for example, a floc trapping cage 220, as shown in FIG.

The flock trapping cage 220 is configured by attaching a bag-like flexible net 222 to a rectangular box-like frame 224 so as to be stretched over at least the bottom surface and the outer peripheral surface (the front surface, the rear surface, and the pair of side surfaces) of the frame 224.

The net 222 is made of a flexible material and does not retain its own shape, but is at least locally reinforced by a three-dimensional rigid frame 224 (made of metal, synthetic resin, wood, etc.) to substantially retain its shape. Therefore, the net 222 itself is an example of a soft filter bag, but the floc trapping cage 220 formed by reinforcing the net 222 with a frame 224 is an example of a hard filter bag.

As shown in the plan view of FIG. 11, the net 222 is arranged in the flocculation tank 40 so as to divide the inner space into an outer space and an inner space. This net 222 is capable of capturing agglomerated flocs formed in the wastewater while allowing the water content of the wastewater to escape as process water.

In order for the net 222 to perform a filtering function in the coagulation tank 40 in this manner, the net 222 can be manufactured using, for example, a mesh sheet.

As shown in plan view in FIG. 11 , the two first stirrers 100 are moved within the longitudinal and lateral movement ranges allocated inside the floc-catching cage 220 . The two first stirrers 100 are prevented from moving beyond the boundaries of the floc-catching cage 220 .

The operator can selectively cause the floc trapping cage 220 to sink or float with respect to the flocculation tank 40 . Raising and lowering the floc trapping cage 220 may be done manually or mechanically.

<Method of raising and lowering cage 220 for catching flocs>

In one example, floc trapping cage 220 is allowed to settle into flocculating layer 40 prior to addition of flocculating agent to the wastewater.

Once the formation of flocculated flocs in the wastewater is completed, the flocculation cage 220 is floated from the flocculation tank 40 .

The flotation separates the wastewater into treated water that leaks out of the net 222 and agglomerated floc that remains trapped within the net 222 . Thus, net 222 is used for both the agglomeration stage and the separation stage. Treated water leaking from the net 222 is discharged to the drain pipe 46 through the waste water outlet 44 .

In another example, the floc trapping cage 220 is allowed to sink into the flocculation layer 40 until the bottom surface of the floc trapping cage 220 rises a predetermined distance (e.g., about 3 to about 10 cm) from the top surface (inner surface) of the bottom 43 of the sink 42 of the flocculation tank 40 before adding the flocculant to the wastewater. In this state, a horizontally extending plate-shaped gap is formed between the lower surface of the cage 220 (net 222) for catching flocs and the upper surface (inner surface) of the bottom portion 43 of the sink 42. As shown in FIG.

In order to form the gap, a spacer may be inserted between the lower surface of the flock-trapping cage 220 (net 222) and the upper surface (inner surface) of the bottom portion 43 of the sink 42, or it may be realized by adjusting the lifting position of the floc-trapping cage 220.

Once the floc formation in the wastewater is complete, the wastewater outlet 44 is unplugged while the floc-catching cage 220 remains submerged. Thereby, the waste water is filtered by the net 222 and the treated water of the waste water leaks out of the net 222 while the agglomerated flocs remain trapped in the net 222 . The treated water passes through the gap toward the waste water outlet 44 , and eventually gathers at the waste water outlet 44 without being obstructed by the solids in the net 222 , and then discharged to the drain pipe 46 .

The drainage separates the wastewater into treated water that leaks out of the net 222 and agglomerated floc that remains trapped within the net 222 . Thus, net 222 is used for both the agglomeration stage and the separation stage.

In this example, after all of the treated water has been drained from the flocculation tank 40, the floc capture cage 220 is floated from the flocculation tank 40 so that the flocculated flocs are collected singly (e.g., in bulk collection mode) for disposal. The flock catching cage 220 is, for example, a lift type in which a hoist, which is at least temporarily fixed in space, winds up a wire rope (see, for example, a hoisting string-like body 240 shown in FIG. 13) to raise and lower the floc catching cage 220 by using a lifter such as a hoist-type lifter to lift up agglomerated flocs.

As shown in the plan view in FIG. 11, the two first stirrers 100 are positioned inside the floc trapping cage 220 in plan view with respect to the flocculation tank 40 configured to include the floc trapping cage 220. On the other hand, the two second stirrers 110 are arranged so as to be located outside the floc capturing cage 220 in plan view.

However, the two second stirrers 110 may be arranged so that at least part of them is positioned inside the floc-catching cage 220 in plan view.

FIG. 12 conceptually shows a flow diagram of assembly of the flocculation device 210 shown in FIG. 10 and wastewater treatment using the flocculation device 210 in chronological order.

First, in step S51, an operator assembles the aggregation tank 40 using the plurality of parts described above.

Next, in step S<b>52 , the operator assembles the floc trapping cage 220 and sinks it into the flocculation tank 40 .

Subsequently, in step S53, the operator arranges the vertically moving unit 90, the horizontally moving unit 80, and the addition stirring unit 60 to the flocculation tank 40 in the same manner as in steps S22-S24 shown in FIG.

Then, in step S54, the operator installs the two second stirrers 110 on the frame 120 of the flocculation tank 40 using the mounting brackets 160 in an inclined state.

Subsequently, in step S55, the operator puts the waste water into the sink 42 of the coagulation tank 40 as raw water. As a result, both the two first agitators 100 and the two second agitators 110 and the floc trapping cage 220 are submerged in the wastewater. A floc trapping cage 220 is submerged completely or partially in the wastewater.

Then, in step S56, similarly to step S27 shown in FIG. 9, the operator puts the flocculant into the hopper 142, and while the flocculant is dispersedly added to the waste water by the hopper 142, the flocculant is stirred by the rotation of the two first stirrers 100. Here, "dispersed addition" corresponds to primary dispersion in air, and "stirring by rotation" corresponds to primary dispersion in liquid.

Also, in step S57, the operator uses the handle 86 of the addition stirring unit 60 to two-dimensionally move it above the flocculation tank 40 in the same manner as in step S28 shown in FIG. A flocculant is thereby dispersed over the surface of the wastewater. Here, "dispersion" corresponds to secondary aerial dispersion.

In addition, in step S58, the flocculant is stirred by two-dimensional movement (translational motion) of the two first stirrers 100 while rotating in the same manner as in step S29 shown in FIG. Here, "translational agitation" corresponds to secondary liquid dispersion.

Also, in step S59, the coagulant is stirred by the rotation of the two second stirrers 110 in the same manner as in step S30 shown in FIG. Here, "stirring due to rotation" corresponds to tertiary liquid dispersion.

These steps S56-S59 are performed in parallel rather than sequentially.

After that, in step S60, the operator pulls up the floc trapping cage 220 from the flocculation tank 40 and floats it above the waste water. As a result, the raw water is solid-liquid separated into the treated water in the flocculating tank 40 and the flocculated flocs in the floc capturing cage 220 .

Subsequently, in step S61, the operator directly discharges the treated water from the aggregation tank 40, or feeds the treated water discharged from the aggregation tank 40 to the separation tank 50, where solid-liquid separation is performed again.

Additionally, in this embodiment, as illustrated in FIG. 10, the net 222 is at least locally reinforced by a rigid frame 224, thereby substantially retaining its shape.

Alternatively, as exemplified in FIG. 13, the present invention may be carried out in a mode in which a net that realizes self-retaining properties in terms of its shape by three-dimensionally joining (or three-dimensionally processing) one or more mesh sheets 230 without using a frame 224 is used as a flocculated floc recovery sheet assembly 234 that filters the wastewater in the flocculation tank 40 and separates and recovers flocculated flocs from the wastewater. In this embodiment, the net or agglomerated floc recovery sheet assembly 234 functions as a filter sheet.

Here, the phrase “three-dimensionally joined (or three-dimensionally processed)” may be, for example, a method of sewing the mesh sheet 230 as a joining method that cannot be disassembled, or a joining method that can be disassembled after use.

In this embodiment, for example, the agglomerated floc collecting sheet assembly 234, as shown in FIG. 13, is configured to form a hexahedron with an open top surface, that is, a pentahedron having four side surfaces (front and rear side surfaces and left and right side surfaces) and a bottom surface.

Here, the "pentahedron" may be locally reinforced by superimposing a thin triangular pyramid on each of the four thin triangular pyramid corners on the bottom surface of another sheet or a thin triangular pyramid as a molded product.

In this example, the agglomerated floc collecting sheet assembly 234 has a size of 900 mm in length, 1800 mm in width, and 500 mm in height in plan view.

In this example, a belt-like upper edge 236 of each of the four mesh sheets 230 constituting the four side surfaces of the aggregated floc collecting sheet assembly 234 (for example, the original upper edge of the mesh sheet 230, the original upper edge of the mesh sheet 230 folded back to the main body side of the mesh sheet 230 and doubled and reinforced, or the original upper edge of the mesh sheet 230 reinforced by overlapping another belt-shaped body) has a plurality of through holes 238 formed in the upper edge 23. 6 are formed discretely. Each through-hole 238 may be reinforced by attaching a metal fitting called an eyelet, for example.

In this example, the agglomerated floc collecting sheet assembly 234 also has one or more lifting cords (eg, ropes, wires, chains, etc.) 240 coupled to at least some of the plurality of through-holes 238 . Each lifting string 240 is an example of a traction device for pulling the aggregated flock collecting sheet assembly 234 .

For example, as shown in FIG. 13, the tip of each lifting string-like body 240 is connected to each through hole 238 so that the other end of each lifting string-like body 240 becomes a free end (for example, an upper end). are both fixed ends (connecting ends) such that the lifting cords 240 loop together with the body (e.g., top edge 236) of the agglomerated flock recovery sheet assembly 234.

In the above example, when the flocculation work using the flocculation tank 40 is completed, the portion of the lifting string-like body 240 exposed from the flocculation tank 40 is lifted manually by the operator or automatically using a power source. As a result, the flocculated floc collecting sheet assembly 234 is floated from the flocculation tank 40 and drained.

At this time, the treated water (supernatant liquid) leaks out from the aggregated floc collecting sheet assembly 234 and remains in the aggregation tank 40, while the aggregated flocs are captured in the aggregated floc collecting sheet assembly 234 and pulled up from the aggregation tank 40, thereby separating the treated water and the aggregated flocs from each other. Therefore, in this separation process, the flocculated floc recovery sheet assembly 234 can be considered to constitute a separation tank in cooperation with the flocculation tank 40 .

<About the flow analysis in the flocculation tank>

Here, a technique will be described in which the powdery flocculant is stably dispersed and added to the waste water by installing the two first stirrers 100, 100 in parallel in the flocculation tank 40. FIG.

However, since the essence of this technique involves the parallel arrangement of the two first stirring shafts 104, 104 of the two first stirrers 100, 100, in order to employ this technique, the two first stirring shafts 104, 104 may be driven by their common body portion 102 (drive source). Focusing on the total number of drive sources, this configuration can be recognized as one first stirrer 100 . Therefore, it is not essential to use two first stirrers 100, 100 to employ the above technique.

First, to explain the background of the development of this technology, powdery flocculants, unlike liquid flocculants, tend to float and not settle or disperse in wastewater because they are porous.

Therefore, the drawback of the powdery flocculant is that it is difficult to effectively disperse the flocculant in the entire wastewater, maximize the portion of the wastewater that comes into contact with the flocculant, and thereby maximize the flocculant efficiency by simply stirring the wastewater after the flocculant is added. In other words, a powdery flocculant cannot exhibit high uniform agitation performance in the flocculation tank 40 by simple agitation.

Furthermore, even if the flocculant is dropped into the wastewater, the flocculant itself immediately clusters and becomes a dumpling state, and the part of the wastewater that comes into contact with the flocculant decreases, so that the uniform dispersion effect of the flocculant is reduced, and the flocculant flocculation efficiency is reduced.

Furthermore, in recent years, the use of solvent-based release agents has been avoided due to social demands for environmental protection and improvement of work environment safety, and water-based release agents have been in the spotlight instead. Therefore, if the wastewater mixed with the release agent is agitated using air bubbles, a large amount of air bubbles are generated in the wastewater, which makes it difficult to recover the flocculated flocs as a product of the flocculant. Therefore, there is also a demand to agitate wastewater without using air bubbles.

Therefore, the present inventor devised a technique in which the two first stirring shafts 104, 104 are arranged in parallel (opposing arrangement, parallel close arrangement) with a longitudinal gap extending substantially in the vertical direction, and the first stirring shafts 104, 104 are all rotated in the same direction, for example, clockwise as illustrated in FIGS. 1, 5, 10 and 14.

According to this technique, a downward vortex (e.g., forced vortex) is generated in the vicinity of the agitation shafts 104, 104 by the joint action of the agitation shafts 104, 104 (e.g., bringing two solid eddies generated by the agitation shafts 104, 104 to rotate in the same direction into close proximity and imparting a rotational force to the portion of the wastewater sandwiched by the solid eddies). As a result, when the flocculant powder is dropped into the hollow of the vortex, the flocculant powder is then drawn into the vortex, causing the flocculant powder to settle toward the bottom 43 of the flocculating tank 40 (bottom).

Herein, the act of "flocculant powder being dropped into the recess of the spiral" includes, for example, the act of "flocculant powder being dropped into the interior or cavity of the recess of the spiral" and/or the act of "flocculant powder being dropped near the top edge of the recess of the spiral or near its outer perimeter."

Further, each agitator 100, 100 is configured such that the water flow generated by the corresponding agitating blade 106 is primarily axial.

When the wastewater is swirled, the free surface of the wastewater surface generally forms an inverted conical depression. This "hollow" is also called a cavity. The vortex is generated in the waste water such that a generally inverted conical depression is formed opening to the surface of the liquid.

A "downward vortex" means a vortex in which, when a solid object is thrown into the vortex, a downward driving force is applied to the solid object.

By the way, one example of the powdery flocculant is produced from naturally occurring volcanic ash and is porous. Therefore, this type of flocculant tends to float in waste water. However, this type of flocculant is harmless, and the pH of the wastewater after it is added is about 8, which is within the neutral range.

Thus, creating the above-described downward swirl in the wastewater facilitates achieving improved agitation, and thus improved flocculation efficiency, while enjoying the physical property benefits of such flocculants.

FIG. 14(a) is a side view for conceptually explaining an example of a flow pattern generated in a flocculation tank 40 by a pair of first stirrers 100, 100 arranged in parallel or facing each other and a pair of second agitators 110, 110 arranged in a staggered arrangement (in a pair of diagonally inclined positions in the flocculation tank 40) in the first or second embodiment, partially different from the examples shown in FIG. , and FIG. 2(b) is a plan view.

As a result of a test conducted by the present inventor on the aggregating device 20 configured in this way, it was confirmed that when the two first stirring shafts 104, 104 rotate in the same direction, a downward vortex is generated in the vertical gap between the pair of first stirring shafts 104, 104 or in the vicinity thereof, that is, in the vicinity of the pair of first stirring shafts 104, 104, as shown in FIG.

FIGS. 15(a)-(c) show a plurality of photographs of actual performance tests of an example (prototype) using a flocculation tank 40 equipped with the flocculation device 20 according to the first or second embodiment.

Specifically, FIG. 1(a) shows a photograph of a flocculation device 20 provided with a pair of first agitators 100, 100 (represented by the term “parallel air rotary agitator” in the figure) and a hopper 142 (represented by the term “flocculant feeder” in the figure) taken in a state in which the rotation of each agitator 100, 100 is adjusted. In this photograph, the parallel air rotary agitator can be seen.

Here, "rotation adjustment" means that each agitator 100, 100 is adjusted to prevent or reduce the situation in which atmospheric air is entrained in the wastewater (e.g., in the vortex created near the first pair of agitation shafts 104, 104) by the agitator impeller 106 (and/or as a result of the pressure being lower at the center of the vortex than at the periphery, air bubbles previously entrained in the wastewater concentrate at the center of the vortex) and excess foam is generated in the wastewater. means the operator's operation or action to adjust the number of rotations (rotational speed) of the stirring shaft 104.

In addition, FIG. 4(b) shows a photograph of a situation in which a downward vortex is generated in the flocculation tank 40. As shown in FIG. In this photograph, the vortices generated near the pair of first stirring shafts 104, 104 are visible. Furthermore, in this photograph, it is also visible that no bubbles are generated in the wastewater in the vicinity of the vortex.

For each agitator 100, 100, if it is an axial flow type that generates a discharge flow in the axial direction, three propeller blades or the like are selected as the corresponding agitating blade 106, for example.

Each of the first stirring shafts 104,104 is equipped with a plurality of stirring blades 106,106. In the example shown in FIG. 1(a), the stirring blades 106 have different diameters along the axial direction of the stirring shaft 104. In FIG.

Specifically, in the illustrated example, large-diameter stirring blades 106 are arranged on the upper side, and small-diameter stirring blades 106 are arranged on the lower side. In this example, the diameter of each of the plurality of stirrer blades 106 decreases as it approaches the free end (tip) of the stirrer shaft 104 .

FIG. 1(c) shows a photograph of a state in which the powdery flocculant is added or thrown into the flocculation tank 40 from the hopper 142. FIG. In this photograph, it can also be seen that the powder falls from the bottom surface of the hopper 142 aiming at the hollow of the spiral.

Said vortices are generated in the wastewater in a substantially positionally stable manner. That is, the vortex has a strong tendency to be generated only in a specific region near the pair of first stirring shafts 104, 104 (for example, a region radially separated from each stirring shaft 104 by about 30 cm to about 50 cm at maximum in plan view).

Therefore, according to this embodiment, the flocculant dropped from the hopper 142 is introduced into the cavities of the whirlpools generated without any leakage, and then drawn downward by the whirlpools and settled toward the bottom 43 of the flocculation tank 40.

As described above, according to the present embodiment, the coagulant, which easily floats, is sent to the bottom portion 43 of the coagulation tank 40 without leakage thanks to the positionally stable generation of the vortex.

Rather, based on the fact that the vortex is stably generated in the specific region, which has been confirmed in advance by the present inventor, as illustrated in FIGS.

Here, the coagulant powder thrown into the wastewater from the hopper 142 is divided into a portion that collides with the bottom portion 43 of the coagulation tank 40 and a portion that does not collide.

Then, as shown in FIG. 14(a), the part of the flocculant powder that has collided with the bottom 43 of the flocculation tank 40 is dispersed in multiple directions (for example, in all directions) by the collision and dispersed in the wastewater.

As shown in FIG. 14, the aggregation device 20 further includes two second stirring shafts 104, 104 of two second stirrers 110 (the total number of which may be one or three or more). The second stirring shafts 104, 104 rotate at least one corresponding second stirring blade 106, 106, respectively, thereby stirring a portion of the flocculant powder that does not impinge on the bottom 43 of the flocculating tank 40, thereby dispersing that portion within the wastewater, thereby dispersing the flocculant powder substantially throughout the flocculating tank 40.

Each second stirring shaft 104 may be detachably attached to the wall of the aggregation tank 40 in an inclined posture, or may be detachably attached to the wall of the aggregation tank 40 (tank wall) in a substantially horizontal posture.

In the installation mode in the inclined position, the discharge flow from each stirring shaft 104 includes both horizontal component (which can be converted into mainly circumferential circulating flow in aggregation tank 40) and vertical component (which can mainly be converted into vertical circulating flow in coagulating tank 40). On the other hand, in the installation mode in a substantially horizontal posture, the discharge flow from each stirring shaft 104 mainly contains only the horizontal component (which can be converted into mainly the circumferential circulating flow in the aggregation tank 40).

Thus, in the present embodiment, the synergistic effect of the active sedimentation effect of the coagulant powder by the pair of first stirring shafts 104, 104 and the diffusing effect of the coagulant powder by the pair of second stirring shafts 104, 104 maximizes the diffusion of the coagulant powder in the coagulation tank 40, and thus maximizes the coagulant efficiency.

Here, each stirrer 110, 110 is configured such that the water flow generated by the corresponding stirring blade 106 is primarily axial.

By the way, according to the present inventor, as a comparative example, when a test was conducted in which only one stirring shaft 104 was used and rotated to stir wastewater, a downward vortex (for example, a forced vortex or solid vortex co-rotating with its stirring blades 106) was generated around the stirring shaft 104. Then, it was confirmed that when the coagulant powder was put into the hollow of the spiral, the coagulant powder was allowed to settle toward the tank bottom 43 .

However, when the wastewater is circulated by the pair of second stirring shafts 104, 104 in the flocculation tank 40, the position of the vortex moves in plan view. That is, in this comparative example, the generated vortex was not stable with respect to position and was fluid.

Therefore, in this comparative example, if the coagulant powder is to be reliably introduced into the cavity of the spiral, the operator must move the hopper 142 (the coagulant injector, the position to drop the coagulant powder, etc.) so as to follow the change in the position of the spiral, which inevitably complicates the work.

Also, in this comparative example, a vortex is generated in the vicinity of itself by only one first stirring shaft 104 . In contrast, in the present embodiment, the two or more first agitating shafts 104, 104 generate two oppositely directed water flows, i.e., two countercurrents or countercurrents, in their adjacent regions, as a result of which a downward vortex or vortex is generated in said adjacent regions.

Therefore, when this comparative example and this example were tested under the condition that the rotation speed of each stirring shaft 104 was the same, it was confirmed that the rotation speed of the vortex was higher in this example, and as a result, the ability to transport the flocculant in the wastewater, that is, the ability to draw the flocculant powder into the tank bottom 43 was high, and thus the ability to spread and flocculate the flocculant powder was improved.

Here, the flow in the aggregation tank 40 will be analyzed more specifically with reference to FIG. 14 .

The flow of the flocculant powder drawn into the tank bottom 43 by the swirl (hereinafter also simply referred to as "flocculant") tends to collide with the tank bottom 43, reverse, and turn into an upward circulating flow having an upward component, as conceptually shown in FIG.

The flocculant transported by the ascending circulation flow is then transported by the circumferential circulation flow and the vertical circulation flow (not shown) generated by the cooperative action of the pair of second stirrers 110, 110, as conceptually shown in plan view in FIG. As a result, the flocculant drawn into the tank bottom 43 by the swirl is agitated throughout substantially the entire flocculation tank 40 so as to be dispersed.

In addition, as conceptually shown in FIG. 4B, the horizontal component of the axial discharge flow from each second stirrer 110 collides with the wall of the aggregation tank 40, and is presumed to be converted into a circumferential circulating flow (or rotating flow).

On the other hand, although not shown, the vertical component of the axial discharge flow from each second stirrer 110 collides with the bottom 43 of the aggregation tank 40, and is presumed to be converted into a vertical circulation flow (or a reciprocating flow).

<Layout of stirring blades on the first stirring shaft>

In the embodiment shown in FIGS. 14 and 15, two groups of first stirring blades 106, 106 corresponding to two first stirring shafts 104, 104 are configured as a plurality of stirring blades 106A, 106B attached to a corresponding one stirring shaft 106 at a plurality of positions different from each other in the axial direction thereof.

That is, in the present embodiment, a plurality of stirring blades 106A and 106B exist as a group of first stirring blades 106 corresponding to one first stirring shaft 104, and a plurality of stirring blades 106A and 106B exist as a group of first stirring blades 106 corresponding to the other first stirring shaft 104.

More specifically, in this embodiment, as shown in FIG. 14(a), for each stirring shaft 104, an upper stirring blade 106A closest to the liquid surface of the waste water and a lower stirring blade 106B closest to the tank bottom 43 are attached.

The upper stirring blade 106A is attached to the stirring shaft 104 so that its axial position can be adjusted when the stirring shaft 104 is assembled (for example, when the stirrer 100 is completed).

An example of the adjustment mechanism is configured to include a relative movement portion (e.g., a slide fitting portion) having a first member attached to one of the stirring shaft 104 and the upper stirring blade 106A and a second member attached to the other and capable of relatively moving in the axial direction, and a lock/unlock portion that locks or unlocks the first member and the second member at a selected axial relative position. In the unlocked state, the first member and the second member are axially movable relative to each other.

In one example, the first member is a shaft member having a circular or square cross-section like a male part, the second member is a hollow member like a female part into which the rod-like member is slidably inserted in the axial direction, the relative moving part is a slide fitting part, and the lock/unlock part is a fastener screwed into one of the shaft member and the hollow member, the tip of which is engaged with the other to be locked, and the tip of which is separated from the other. unlocked state.

According to this adjustment mechanism, the operator can adjust the vertical distance of the upper stirring blade 106A from the liquid surface of the waste water when the stirrer 100 is assembled as a finished product.

For example, the operator adjusts the height direction position of the upper stirring blade 106A close to the liquid surface so that even a part of it is exposed from the liquid surface during the rotation of the upper stirring blade 106A and the exposed portion is air in the atmosphere.

In this embodiment, two or two groups of first stirring blades 106 , 106 corresponding to the two first stirring shafts 104 , 104 may be configured as one-stage or multiple-stage stirring blades 106 .

Specifically, each stirring shaft 104 may have only one stage or multiple stages of stirring blades 106 for each stirring shaft 104 . In the former case, one stage of impeller 106 constitutes one impeller per stirring shaft 104, while in the latter case, multiple stages of impeller 106 constitute one group of impeller per stirring shaft 104.

In this embodiment, the upper impeller 106 (eg, the uppermost impeller 106A in the example shown in FIG. 14(a)) is mainly used for generating the swirl.

In this embodiment, the lower stirring blade 106 (in the example shown in FIG. 14(a), for example, the lowest stirring blade 106B) is mainly used to assist the collision speed of the flocculant drawn into the tank bottom 43 by the swirl against the tank bottom 43 (auxiliary acceleration of the sedimentation of the drawn flocculant) to promote the diffusion of the flocculant. and/or to promote re-diffusion.

In another example, in order to give priority to the vortex generation efficiency, one or more stages of stirring blades 106 may be attached to one stirring shaft 104 only at positions close to the liquid surface.

<Hood as wind protection member for suppressing scattering of flocculant powder by wind>

Furthermore, in the present embodiment, although not shown, there is a hood extending downward from the bottom surface 250 of the hopper 142, which is an example of a flocculant feeder (for example, the passing surface of the sieve 143, the first through hole 150, etc., as shown in FIG. This hood is placed so that its free end or tip faces the liquid surface.

Since the flocculant used this time is a powder, it is more susceptible to the effects of wind than when it is liquid. However, if the above-described hood is present, substantially the whole of the path for dropping the flocculant powder, which is located between the above-mentioned drop start region and the above-mentioned liquid surface, will not be disturbed by the wind.

The hood is configured as, for example, an enclosing member, a shielding member, and a windbreak member. Also, the hood is configured to have a tubular shape, for example. The hood may also be constructed of metal or plastic or composites thereof. The hood may also be constructed of a perforated or permeable material so that the operator's observation of the vortex is not visually obstructed by the hood.

As an effect of this hood, when the flocculant is dropped from the hopper 142, the flocculant is shielded from the outside air over substantially the entire dropping path, thereby making the path of the flocculant less susceptible to the adverse effects of wind.

As a result, the position on the liquid surface where the coagulant powder is actually dropped as a relative position to the actual position of the dropping start region, that is, the position of the addition stirring unit 60 (which may be constant or variable during stirring) is stabilized. As a result, it becomes easier for the operator to target the spiral pits generated on the liquid surface and charge the coagulant powder with high accuracy without deviating from the target.

As a result, if the operator two-dimensionally moves the addition stirring unit 60 so that the position of the dropping start region matches the position of the recess of the spiral that is actually generated, the work of accurately dropping the flocculant into the recess of the spiral at the fixed position of the addition stirring unit 60 is facilitated without being affected by the wind as long as the position of the spiral does not change.

<Mechanism for Adjusting Rotational Speed of Stirring Shaft 104>

Furthermore, in the present embodiment, the body portion 102 itself having a drive source (e.g., an air motor) or an air hose extending from the body portion 102 (connected to an external high-pressure source, etc., although not shown) has a control valve (e.g., a variable throttle valve) or a regulator (e.g., a controller that remotely adjusts the pressure of the high-pressure source) for an operator to adjust the rotational speed of the stirring shaft 104, which can be operated by an operator near the stirring shaft 104.

As a result, it is easier for the operator to operate to adjust the rotational speed of the agitation shaft 104 than if neither the regulating valve nor the regulator were present, thereby facilitating, for example, adjusting the depth of vortices generated in the wastewater.

By the way, in the case of using the above-mentioned downward vortex, there is an advantage that substantially all of the dropped powdery flocculant (for example, it is porous and thus easily floats in the wastewater) is drawn into the tank bottom 43, making it easy to disperse the flocculant (flocculant powder) substantially throughout the flocculation tank 40. On the other hand, since the vortex is generated by the rotation of the stirring blades 106 near the liquid surface, air in the atmosphere collides with the stirring blades 106 and enters the wastewater. It has the disadvantage that it can become entangled and make the operation of recovering the flocs from the wastewater difficult.

As a result of numerous tests and studies, the present inventor adjusted the height position of the upper stirring blade 106A as described above and adjusted the rotational speed of the upper stirring blade 106A as described above in order to eliminate or reduce the above drawbacks without impairing the above advantages.

In the present embodiment, the following method of stirring/mixing powder particles is carried out.

That is, in this method, (a) a single stirring shaft 104 arranged in a posture extending substantially vertically in a tank 40 containing the wastewater as an example of a liquid is rotated, or a plurality of stirring shafts 104 arranged in parallel (closely arranged in parallel) are rotated in the same direction to rotate the stirring blades 106 coaxially therewith, thereby forming a generally inverted cone shape in the wastewater contained in the tank 40 so as to open a downward vortex to the liquid surface of the wastewater. (b) a dropping step of dropping coagulant powder, which is an example of a granular material, toward the recesses of the created spiral;

In this embodiment, the two first stirrers 100, 100 have both a swirl generating part (for example, the upper stirring blade 106A) and the original stirring part (for example, the lower stirring blade 106B), but the swirl generating part and the original stirring part are separately separated, and the swirl generator having a pair of rotating blades rotating in the same direction and at least one first stirrer 100 that mainly contributes to the generation of the swirl. may be installed in the flocculation tank 40 as individual components.

<About the stirring capacity of the stirrer>

Here, considering the stirring function of each part of the first stirrer 100, since the first stirring blade 106 is actively rotated by the motor, regardless of whether the first stirrer 100 is in a translational motion or in a stationary state, it is of course possible to have a stirring function for the surrounding wastewater.

On the other hand, the shaft 104 of the first stirrer 100 is actively rotated by the motor like the first stirring blade 106, but the surface of the shaft 104 does not substantially have unevenness. Therefore, this shaft 104 does not substantially affect the surrounding water flow and has no agitating function for the surrounding waste water in the stationary state of the first agitator 100 .

However, since this shaft 104 agitates and affects the surrounding water flow during the translational movement of the first agitator 100, thereby having an agitation function for the surrounding waste water, this shaft 104 effectively functions as a "passive agitation member."

Therefore, the first stirrer 100 has both a stirring blade 106 as an active stirring member (a member that can perform a stirring action without depending on the translational motion of the first stirrer 100) and a shaft 104 as a passive stirring member (a member that cannot perform a stirring action without depending on the translational motion of the first stirrer 100).

Therefore, in the above-described several embodiments, the first stirrer 100 is equipped with the stirring blades 106 as active stirring members in order for the addition stirring unit 60 to achieve the stirring function, but the present invention may be implemented in a manner in which, for example, the first stirrer 100 is equipped with a shaft (non-rotating member, non-rotating member, etc.) that does not rotate relative to the first stirrer 100 as a passive stirring member instead of the motor, the rotating shaft 104 and the rotating stirring blades 106. .

This is because the stirring member is translated relative to the flocculation tank 40 as the addition stirring unit 60 is moved relative to the flocculation tank 40, and the translational movement stirs or agitates the waste water in the flocculation tank 40, thereby dispersing the flocculant in the liquid.

Here, the “passive stirring member” is defined as having a movable part that passively moves continuously or reciprocally at least in the rotational direction, the front-rear direction, or the left-right direction in plan view, for example, during the translational movement of the first stirrer 100 due to an external force (relative water flow, etc.).

Therefore, the “passive stirring member” can be specifically configured as a rod-shaped member (round, square, etc.) as a non-rotating member extending generally downward from the main body 102 of the first stirrer 100, or can be configured as a plate-shaped member (blade, spiral, etc.).

If the above-described aspect is adopted, the structure of the first stirrer 100, and thus the structure of the addition stirring unit 60, is simplified and the overall weight is reduced, compared with the case where the first stirrer 100 is equipped with the motor and the stirring blade 106 in order to realize the stirring function.

Furthermore, in the above-described several embodiments, the addition stirring unit 60 is configured to perform both dispersed addition of the flocculant and stirring of the flocculant, but instead of this, the present invention may be implemented in a manner in which the flocculant is exclusively dispersedly added without stirring the flocculant, thereby reducing the weight and simplifying the structure of the addition stirring unit 60.

Furthermore, in these embodiments, in addition to the movable first stirrer 100, a fixedly installed second stirrer 110 is also provided in the flocculation tank 30. Alternatively, if the stirring capacity of the first stirrer 100 is sufficient, the present invention may be implemented in a manner in which the second stirrer 110 is not provided in the flocculation tank 30, thereby realizing weight reduction and structural simplification of the flocculation device 20.

As described above, several embodiments in which the present invention is applied to a wastewater treatment system used in a coating film cleaning process in a wet coating film stripping operation have been described, but these are only examples, and the present invention can be used for other applications, such as buildings (houses, buildings, etc.) without using a stripping agent, steel towers (e.g., power transmission towers, communication towers, etc.) that are long and thin structures that are constructed using a steel frame structure, civil engineering structures (bridges, etc.), ships, vehicles (automobiles, trains, etc.), airplanes, and the like. It can be applied to wastewater treatment systems used for cleaning the surfaces of objects or structures in which wastewater, which may contain hazardous substances, is generated during operation.

[Third embodiment]

A third exemplary embodiment of the present invention will now be described. However, elements common to the first or second embodiment described above will be referred to with the same reference numerals to omit redundant description, and only different elements will be described in detail.

FIG. 16 is a front sectional view showing the flocculation device 310 of the wastewater treatment system 300 according to this embodiment together with the separation device 30. As shown in FIG.

The flocculation device 310 has a flocculation tank 40 capable of containing the wastewater and having a wastewater outlet 44 as a drain at its bottom 43 .

The flocculation device 310 further has a flexible filter bag 312 installed in the flocculation tank 40, which filters the waste water injected into the filter bag 312 while the waste water is discharged from the waste water outlet 44.

The flocculating device 310 further includes a spacer 320 installed between the bottom portion 314 of the filter bag 312 and the wastewater outlet 44, which prevents clogging of the wastewater outlet 44 by forming a gap between the bottom portion 314 of the filter bag 312 and the wastewater outlet 44 in such a manner that at least the liquid component of the wastewater can pass through the gap. In this embodiment, the spacer 320 is an example of an anti-clogging tool.

FIG. 17(a) is a perspective view showing the spacer 320 together with the waste water outlet 44, and FIG. 17(b) is a side sectional view.

As shown in the figure, the spacer 320 has a support surface that supports the filter bag 312 from below at a position above the upper surface of the tank bottom 43 in the entire length direction, or has a support surface that supports the filter bag 312 from below at a position above the other portions in the central portion of the length direction. A spacer 320 is placed on the upper surface of the tank bottom 43 such that the support surface faces the waste water outlet 44 with a gap therebetween.

As shown in the figure, the spacer 320 uses a sheet-like wire mesh and is configured to have a three-dimensional shape with a hollow inside. For example, it may be configured to have a similar shape using a sheet-like wire mesh. The spacer 320 forms a trapezoidal cavity with the surface of the tank bottom 43 in a side view.

As shown in the figure, the tank bottom portion 43 has a shape in which the portion where the waste water outlet 44 is present and the peripheral portion thereof have substantially the same height when viewed from the side. In this configuration, the spacer 320 rests on the upper surface of the tank bottom 43 , thereby displacing at least the portion of the bottom of the filter bag 320 facing the waste water outlet 44 upwards from the waste water outlet 44 .

In the flocculation tank 40, the wastewater and flocculant powder can flow through the spacer 320 or through the cavity below the spacer 320 to reach the wastewater outlet 44, as indicated by the multiple arrows in FIG.

In one example, the spacers 320 have a length dimension substantially equal to the length dimension of the tank bottom 43, thereby inhibiting longitudinal displacement of the spacers 320 during flow of the wastewater within the flocculation tank 40.

In another example, the spacer 320 has a length dimension that is less than the length dimension of the tank bottom 43, and the support surface has a length dimension that allows the support surface to remain spaced apart from the wastewater outlet 44 even if the spacer 320 is longitudinally displaced during the flow of the wastewater in the flocculation tank 40.

In the example shown in FIG. 17, the waste water outlet 44 is arranged substantially in the center of the tank bottom 43 in plan view, and the spacer 320 has a top surface in substantially the center of the spacer 320 in side view.

In this example, the spacer 320 has a form in which the top surface and a pair of slopes sandwiching the top surface from both sides are arranged in a line in a plan view, and the top surface and the pair of slopes are continuously connected without a substantial step difference in a side view. Each slope inclines toward the tank bottom 43 as the distance from the top surface increases in a side view. The top surface faces a waste water outlet 44 with a gap therebetween.

Furthermore, the spacer 320 is detachably installed with respect to the aggregation tank 40 .

FIG. 18 is a perspective view showing an example of the filter bag 312 together with the spacer 320 and the anti-surfacing device 322. As shown in FIG.

The filter bag 312 is a soft type that does not stand alone in a stand alone state, and its shape depends on the shape of the inner wall surface of the coagulation tank 40 after it is installed in the coagulation tank 40 . Alternatively, the filter bag 312 may be configured as a hard type that is self-supporting in terms of shape in the stand alone state.

When the filter bag 312 is of the soft type as described above, the upper edge of the filter bag 312 can be detachably attached and fixed to the upper edge of the coagulation tank 40 using a fixture (not shown).

On the other hand, since the bottom of the filter bag 312 may unintentionally float from the tank bottom 43 during agitation of the waste water, as shown in FIG. The floating prevention tool 322 is, for example, one that presses the bottom of the filter bag 312 against the tank bottom 43 using its own weight (for example, a weight, a weight), and is configured as a metal angle material or a heavy object having another shape.

FIG. 19 is a process chart conceptually representing in chronological order a plurality of processes carried out using the wastewater treatment system 300 according to this embodiment.

In order to perform wastewater treatment using the wastewater treatment system 300, first, in step S301, an operator carries the kit of the flocculation tank 40 to the site where the above-described wet stripping work is performed, and assembles the flocculation tank 40 at the site. In this embodiment, the wastewater is treated using the coagulation tank 40 at the site where the wet stripping was performed and the wastewater was generated. This is an example of an on-site wastewater treatment scheme.

Next, in step S<b>302 , the operator places the spacer 320 on the surface of the bottom 43 of the assembled flocculation tank 40 . Subsequently, in step S<b>303 , the operator installs the soft-type filter bag 320 inside the coagulation tank 40 . Then, in step S304, the operator places several anti-floating devices 322 on the surface of the bottom 314 of the filter bag 312. FIG.

In another example, the filter bag 312 is coupled to the spacer 320 at the bottom 314 of the filter bag 312 prior to installation in the flocculation tank 40 using a coupler that sandwiches a pair of plates against a mating member. Thereby, when installing in the flocculation tank 40 , the spacer 320 moves integrally with the filter bag 312 and is retained on the upper surface of the tank bottom portion 43 . According to this example, the operator can omit the work of placing the surfacing prevention tool 322 on the bottom portion 314 of the filter bag 312, thereby improving workability.

After installing the filter bag 320 inside the flocculation tank 40, the operator, as shown in FIG.

Subsequently, in step S305, the operator pours the wastewater (also referred to as “raw water” in the sense of the object to be filtered, separated, and detoxified) into the coagulation tank 40 in parallel with or after the wet stripping operation.

After that, in step S306, after starting the pair of first stirrers 100, 100 and the pair of second stirrers 110, 110, the operator adjusts the pair of first stirrers 100, 100, including the above-described rotation adjustment, so as not to generate bubbles exceeding the allowable limit in the wastewater in the flocculation tank 40, and to ensure that the vortex is stably generated as planned in terms of scale and position. Do it while

Subsequently, in step S307, the operator adds flocculant powder to the wastewater by dropping it from the hopper 142. As shown in FIG. At this time, the operator drops the added flocculant powder aiming at the downward spiral depressions generated in the wastewater.

Further, the operator moves the addition stirring unit 60 relatively to the flocculation tank 40 two-dimensionally in a plane, thereby moving the dropping position of the coagulant powder over substantially the entire wastewater, and scatters the coagulant powder two-dimensionally to improve the stirring efficiency.

After that, in step S308, the coagulant powder added in the flocculating tank 40 is agitated over substantially the entirety of the aggregating tank 40 by the agitating action of the first and second agitators 100,100.

Subsequently, in step S309, the wastewater is solid-liquid separated by agglomeration. The wastewater is then drained from the wastewater outlet 44 in step S310.

Subsequently, in step S311, the wastewater is primarily filtered by the filter bag 312 while the wastewater passes through the filter bag 312. FIG. Thereafter, in step S312, the primarily filtered wastewater is introduced into the separation device 50, and the separation device 50 performs secondary filtration on the wastewater.

In the present embodiment, the minimum trapped particle size of the filter bag 312 is set larger than the minimum trapped particle size of the separation tank 50, whereby primary filtration is performed in the coagulation tank 40, and secondary filtration with a higher filtration accuracy than the primary filtration is performed in the separation device 50, respectively.

20A is a side cross-sectional view showing another example of the spacer 320 shown in FIG. 16, FIG. 20B is a side cross-sectional view showing still another example, FIG. 20C is a side cross-sectional view showing still another example, and FIG. 20D is a side cross-sectional view showing still another example.

In each of the examples shown in FIGS. 4A to 4C, the tank bottom 43 has a configuration in which the portion where the wastewater outlet 44 exists and the peripheral portion thereof have substantially the same height when viewed from the side.

On the other hand, in the example shown in FIG. 4D, the surface of the tank bottom 43 is a stepped surface when viewed from the side, and the tank bottom 43 has a portion (lower portion) where the waste water outlet 44 exists (lower portion) than its peripheral portion (basic portion, i.e., higher portion).

In this example, a spacer 320 is retained within tubular connection 326 , thereby displacing at least the portion of bottom 314 of filter bag 312 facing waste water outlet 44 upwardly from waste water outlet 44 .

In the example shown in FIG. 4A, the spacer 320 has a chevron cross section so that a triangular cavity is formed on the surface of the tank bottom 43 . In this example, spacer 320 does not have a flat top surface, but has a pair of sloping surfaces connected to each other.

In the example shown in FIG. 4B, the spacer 320 has a stepped cross-section with a high portion and a pair of low portions sandwiching the high portion so that a stepped cavity is formed on the surface of the tank bottom 43. In this example, the spacer 320 has a flat top surface as a high portion and a pair of flat surfaces sandwiching it as a pair of low portions.

In the example shown in FIG. 4C, the spacer 320 has a flat top surface along the entire length so that a rectangular cavity is formed on the surface of the tank bottom 43. In the example shown in FIG.

In the example shown in FIG. 4(d), the spacer 320 has a tubular shape so as to be inserted into the tubular connecting portion 326 with a radial gap left. In this example, the upper surface of the spacer 320 is substantially the same as the peripheral surface of the cylindrical connecting portion 326 of the tank bottom 43 (basic surface of the tank bottom 43).

However, spacer 320 can be configured to have other shapes.

[Fourth embodiment]

Technical field

Embodiments described below relate to techniques for cleaning used sheets, and in particular to techniques for cleaning flexible used sheets on which a liquid agent and/or a plurality of non-uniformly sized solids remain as waste, thereby enabling reuse or disposal of the used sheets. That is, the present embodiment embodies the technical idea of a method and system for cleaning used flexible sheets.

Background technology

A technique is already known in which a member on which unnecessary substances remain is treated as a member to be processed, and the unnecessary substances are removed from the member to be processed.

In addition, Patent Document 11, which will be described later, discloses a dry coating film peeling technique that removes paint from the member as an unnecessary material by subjecting the member to blasting (a method of projecting particles to collide with the surface to be treated) for the purpose of recycling used members that have been coated.

The same document further discloses a dry cleaning technique in which, after the removal, the surface of the base material exposed by the removal is blown with air to remove coating pieces and the like from the surface.

On the other hand, Patent Document 12 listed below discloses a technique for removing asbestos from building members sprayed with asbestos by a mechanical removal method for the purpose of protecting the human body from health hazards caused by asbestos.

The document further discloses, as the "mechanical removal method", a method of scraping asbestos from building members using a sharp blade member such as a knife or a steel brush, and a method of scraping asbestos from building members using a rotating brush.

The same document further discloses a technique of sealing the removal workplace with a plastic sheet and installing a suction blower having a filter inside to suck asbestos.

By the way, in specific cases, for example, when it is necessary to comply with the notification dated May 30, 2014 from the Ministry of Health, Labor and Welfare because it is confirmed that harmful substances such as lead are present in the existing paint film attached to the base of the structure, buildings (houses, buildings, etc.), steel towers that are long and thin structures constructed using a steel frame structure (e.g., power transmission towers, communication towers, etc.), civil engineering structures (bridges, etc.), ships, vehicles (automobiles, trains, etc.). , In order to repaint the surface of a structure such as an airplane or the structure, the existing coating film already applied to the surface is peeled off from the surface of the structure (substrate), and then a new paint is applied to the same surface of the structure.

Against the background of such circumstances, the present inventor developed a method for removing a coating film prior to completion of the present embodiment (see FIG. 22).

The developed coating stripping method includes a wet stripping step of applying air bubbles of a liquid stripping agent to the surface of a structure to thereby strip the existing coating from the surface of the structure, and a wet cleaning step of spraying cleaning water onto the surface of the structure to clean the surface of the structure after the application. This coating film peeling method is disclosed in Patent Document 13 listed below.

By the way, when carrying out this coating film peeling method, a waste water treatment step is required in which the washing water sprayed onto the surface of the structure is recovered as waste water after use and treated.

Then, the inventors of the present invention realized that there is a demand for this wastewater recovery treatment, for example, from the viewpoint of effective utilization of resources, that the wastewater should be partially or completely detoxified and reused as new washing water.

Based on such knowledge, prior to the present invention, the present inventor developed a wastewater treatment process for recovering and treating the washing water sprayed on the surface of the structure after coating the release agent as wastewater, and obtained Japanese Patent No. 6853599 for this. This patent publication is incorporated herein by reference as US Pat.

Specifically, in the wastewater treatment process, a water collection process for collecting the wastewater, a coagulation process using a coagulation tank, and a separation process using a separation tank are performed in order.

Here, the "water collecting step" includes a step of filtering the wastewater using a filter sheet, which is a flexible mesh sheet, as will be described in detail later.

Further, the "aggregation step" is, for example, a step of introducing the wastewater into a flocculation tank after the filtration, adding a powdery or granular flocculant to the wastewater, and flocculating the target substance in the wastewater as flocculation.

Further, the “separation step” is, for example, a step of introducing the waste liquid from the aggregation tank into the separation tank after the aggregation process is completed, and allowing the waste liquid to pass through the filtration section in the separation tank, thereby solid-liquid separating the waste liquid into treated water and aggregated flocs.

Prior art documents Patent Document 11: JP-A-2003-200349 Patent Document 12: JP-A-3-221669 Patent Document 13: Japanese Patent No. 6853599

Problem to be solved

After that, the inventor conducted various tests and various researches and developments in order to improve the practicality of the developed wastewater treatment technology.

As a result, the inventors of the present invention have also noticed that the wastewater recovery treatment has the following requirements, for example, from the viewpoint of effective use of resources.

In other words, the inventors of the present invention have noticed that there is also a demand for cleaning and reusing the members used for carrying out this wastewater treatment step and the members used in the preceding steps, such as the above-mentioned wet stripping step and wet cleaning step.

Furthermore, the present inventors have found that it is effective to select, for example, a filter sheet for filtering used wash water when collecting used wash water in the above-described water collection process, or a filter sheet used in the above-described coagulation tank or separation tank, as "members used for carrying out this wastewater treatment process."

Because the filter sheet is a mesh sheet, the filter sheet usually contains a part of the stripping agent (an example of the liquid agent) as an unnecessary matter, a piece of the existing coating film fragmented (an example of solid matter), and the like.

Specifically, the stripping agent as an unnecessary substance remaining on the filter sheet is, for example, a stripping agent applied to the surface of the structure in the wet stripping step preceding the wastewater treatment step, and then dissolved in the wash water in the wet washing step preceding the wastewater treatment step to form droplets.

In addition, coating film pieces as another unnecessary matter remaining on the filter sheet are an example of solid matter incidentally generated in the wet cleaning process preceding the wastewater treatment process.

Furthermore, the inventors of the present invention have found that it is effective to select, as the "member used in the wet stripping process", an auxiliary member for assisting the wet stripping, rather than the object to be directly processed in the process.

In the wet peeling process, as such an auxiliary member, there is a release agent scattering prevention sheet for preventing the droplets from splashing when the release agent liquid hits the surface of the structure. There is a possibility that splashes of the release agent may scatter on the release agent scattering prevention sheet, and the liquid component of the release agent (including coating film pieces in some cases) may adhere as unnecessary residue.

Furthermore, the inventors of the present invention have found that it is effective to select, as the "member used in the wet cleaning process", an auxiliary member for assisting the wet peeling, rather than the object to be directly processed in the process.

In the wet cleaning process, as such an auxiliary member, there is a coating film scattering prevention sheet for preventing splashes (such as splashes of the cleaning water used in the wet cleaning process and splashes of the release agent applied to the surface of the structure in the wet stripping process preceding the wet cleaning process) from splashing together with the coating film fragments adhering to the surface of the structure as a result of the liquid called cleaning water hitting the surface of the structure. There is a possibility that the droplets and the coating pieces may adhere to the sheet for preventing scattering of coating film fragments as unwanted residues.

Here, the present inventor proposed that the "filter sheet", the "release agent scattering prevention sheet" and the "coating film fragment scattering prevention sheet" should all be configured as flexible members, i.e., members that do not have self-holding properties in terms of their shape and are deformed by external force, in order to meet the demand for high storability.

This type of flexible sheet has the characteristic that it is easy to realize a compact storage form by folding, folding, or bending into a roll shape, and it is also easy to develop it into a three-dimensional shape or a flat shape to realize a use state.

Here, the "flexible sheet" may be configured using a soft material or a hard material, but may be divided into a plurality of blocks and configured such that the blocks are joined in a foldable or bendable manner, or in other cases.

However, the materials for the above-mentioned "filter sheet", "removing agent scattering prevention sheet" and "coating film fragment scattering prevention sheet" are not always of the same type due to their different uses.

In response to such a proposal by the present inventor, none of Patent Documents 11 to 13 discloses selecting a flexible sheet having material properties that do not have self-retaining properties as an object to be cleaned, and cleaning and reusing it.

Further, none of Patent Documents 11 to 13 discloses that a used sheet that has been used during a process other than the sheet cleaning process prior to the sheet cleaning process and on which a liquid agent and/or a plurality of solids having uneven sizes remain as unnecessary materials is selected as an object to be cleaned, washed, and reused.

Here, "liquid agent" is defined, for example, as a substance that is used on the object to be cleaned in order to achieve or facilitate the achievement of its purpose in the relevant process. Also, "solids" are defined, for example, as substances that separate from the object to be cleaned.

Furthermore, none of Patent Documents 11 to 13 discloses wet cleaning of used sheets for reuse.

In addition to the above-mentioned demands, there is also a demand to remove harmful substances from used sheets and to legally dispose of the used sheets.

By the way, the term "sheet" is used throughout the application documents to mean, for example, a thin belt-like member, a thin rectangular member, a thin member having a flat cross section, and the like.

In addition, to explain the manufacturing method, this type of sheet is manufactured, for example, by weaving a plurality of threads made of synthetic resin.

Therefore, with regard to the sheet manufactured in this way, the air permeability of the sheet and its degree are determined depending on, for example, the size of gaps between a plurality of threads in the knitted state and the characteristics of the surface coating.

Sheets are classified into a low-permeability type that has almost no air permeability, high waterproofness, and high airtightness, such as what is called a blue sheet or a flameproof sheet, and a high-permeability type that has a mesh shape and is rich in air permeability (for example, a type 1 mesh sheet).

According to the classification, among the above-mentioned "filter sheet", "removing agent scattering prevention sheet", and "coating piece scattering prevention sheet", all of which belong to the sheet, "removing agent scattering prevention sheet" and "coating film piece scattering prevention sheet" have a priority purpose of preventing scattering, so, for example, the former low air permeability type is basically adopted. On the other hand, since the "filter sheet" is intended for filtration, the latter highly breathable type and mesh type are adopted.

Against the background of these circumstances, the present embodiment (technical idea) aims to provide a technique for washing a flexible used sheet in which a liquid agent and/or a plurality of solids having uneven sizes remain as unnecessary matter, and enabling reuse or disposal of the used sheet.

Problem-solving means

A sheet cleaning system (hereinafter simply referred to as "system") 10 according to the present embodiment will be described in detail below with reference to FIGS.

FIG. 21(a) is a partial cross-sectional side view of system 10, and FIG. 21(b) is a partial cross-sectional plan view.

The system 10 cleans sheets of residual debris that were used during the performance of the other steps preceding the sheet cleaning method (e.g., the wet stripping, wet cleaning, and wastewater treatment steps described above), thereby allowing reuse or disposal of the used sheets.

FIG. 22 is a process diagram schematically showing the above-described sheet cleaning method performed using the system 10 in chronological order, together with the above-described other preceding and subsequent processes (for example, a process of reusing the used sheet for another process after cleaning).

In the present embodiment, as the "used sheet", for example, as shown in FIG. 22, it is possible to select the release agent scattering prevention sheet used during the preceding wet coating process, the coating film fragment scattering prevention sheet used during the preceding wet cleaning process, or the filter sheet used during the preceding waste water treatment process.

<Wastewater treatment unit>

An example of a filter sheet used during the execution of the wastewater treatment process is disclosed in US Pat.

FIG. 34 of the present application shows in perspective view an example of a double sheet 202 as part of a wastewater treatment unit 200 used to perform the wastewater treatment process, together with a scaffolding 210, to illustrate an example of a filter sheet as an example of a used sheet that is cleaned by a sheet cleaning method according to some embodiments of the present invention.

As is well known, the scaffolding 210 includes a plurality of pillars 212 extending vertically from the ground as an example of a support surface (foundation surface), a flooring 214 suspended (supported) by the pillars 212 in a posture extending in the horizontal direction, supporting the feet of the worker from below, and enabling the worker to perform a high-pressure cleaning operation (the wet cleaning process) using a cleaning gun 216 that injects cleaning water at high pressure, and a plurality of handrails (not shown). configured to have a member;

The floor material 214 is configured by, for example, a member having a plurality of openings (through which washing water passes) in plan view.

The scaffolding 210 is provided as a scaffolding for a worker who cleans and strips a structure 218, which is an example of an object to be cleaned.

The double sheet 202 is placed on a scaffolding 210 placed on a structure 218 for workers at a position below its flooring 212 . The double sheet 202 is constituted by an upper filter sheet 220 and a lower water collection sheet 222, which are arranged so as to overlap each other in plan view.

<Filtration sheet>

The filter sheet 220 is configured to receive the washing water (mainly used washing water that has collided with the surface of the structure 218 and bounced back there) jetted from the washing gun 216 as waste water, filters the waste water, and captures and recovers coating film pieces and the like as solids from the waste water.

The filter sheet 220 is a flexible mesh sheet, and is stretched and suspended in the horizontal direction by a plurality of handrails selected from the plurality of handrails. The filter sheet 220 captures some of the coating debris from the received wastewater due to the mesh of the mesh sheet.

To explain the filtering action in detail, the wastewater introduced into the filter sheet 220 is size-sorted or shape-sorted according to the size and shape of the mesh of the filter sheet 220 into those that are trapped and those that pass through without being trapped.

The filter sheet 220 captures pieces larger than the mesh among a plurality of pieces of coating film (peeling debris, etc.) and pieces initially mixed in the wastewater, thereby separating and collecting pieces smaller than the mesh. The primary purpose of this recovery is, for example, to prevent clogging of drain pipe 138 (see FIG. 30) and other pipes connected to it by the wastewater flowing with large solids into those pipes.

This filter sheet 220 allows washing water (fresh water) in the waste water, and a plurality of pieces of the coating film (exfoliation residue, etc.) and fragments smaller in size than the mesh to be first mixed in the waste water to flow out.

<Water collection sheet>

The water collecting sheet 222 is configured to receive the wastewater filtered by the filter sheet 220 from the filter sheet 220 and guide the filtered wastewater to the wastewater outlet 224 by using its own weight. The water collecting sheet 222 is mainly composed of a flexible non-mesh sheet, and is suspended in a horizontally stretched and unfolded state by a plurality of handrails selected from the plurality of handrails.

The water collecting sheet 222 has a bottom portion 222b at its central portion that is lower than its peripheral portion 222a, and as a whole has a generally mortar shape. When the water collection sheet 222 receives the wastewater from the filter 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. At its bottom 222b is installed a waste water outlet 224 for sending waste water downstream.

The waste water outlet 224 is connected to the flocculation tank and the separation tank via a connection pipe 230 and a drain pipe (not shown). The aggregation step is performed using the aggregation tank, and the separation step is performed using the separation tank.

As described above, there are several candidates for the "used sheet" on which the sheet cleaning method according to this embodiment is performed. In this embodiment, the filter sheet 220 is selected as the "used sheet".

As mentioned above, the filter sheet 220 is used to filter the used wash water used in the wet wash process. In the used wash water, there is a possibility that the peeling agent applied to the surface of the structure in the wet peeling process, a plurality of pieces of coating film appearing on the surface of the structure in the wet cleaning process (fragmented pieces of the existing coating film, etc.), etc., are mixed in the used wash water.

In the field of paint film peeling, generally, a plurality of pieces of paint film appearing on the surface of a structure are not uniform in size, and large sizes (e.g., cm order) and small sizes (e.g., mm order and smaller than 1 mm) are mixed.

Therefore, when the filter sheet 220 is selected as the "used sheet", there is a possibility that the stripping agent (an example of the "liquid agent") and the plurality of coating film pieces (an example of "a plurality of solids with non-uniform sizes") remain as "undesirables" on the "used sheet".

On the other hand, the filter sheet 220 is configured as a mesh sheet as described above. Therefore, since the filter sheet is constructed by weaving a plurality of threads with a larger gap than the low-air-permeability sheet, it has high air-permeability.

Therefore, in the used filter sheet 220, some of the solids may adhere to or become entangled with the fibers of the filter sheet 220 and remain as unnecessary matter.

Therefore, in the present embodiment, the above-described sheet cleaning method is performed on the used filter sheet 220 for the purpose of separating and removing the residue from the filter sheet 220 as completely as possible, that is, so that the filter sheet can be reused or legally discarded.

Furthermore, this filter sheet 220 is constructed by weaving a plurality of threads made of a soft material, and has a thin plate shape as a whole. Therefore, since this filter sheet 220 does not have self-retaining properties with respect to its overall shape, it has flexibility. As a result, while the filter sheet 220 can easily transition between, for example, the deployed state and the deformed state, an external force must be applied to the filter sheet 220 to maintain the deployed state.

Furthermore, this filter sheet 220 has a generally rectangular shape with a length dimension and a width dimension in a plane developed state.

Based on the circumstances described above, the system 10 has been developed for the purpose of cleaning the filter sheet 220 as the sheet to be cleaned SC.

Schematically, as shown in FIG. 21, this system 10 includes a scaffold 20 as a support frame, which is temporarily installed by an operator assembling structural members such as multiple steel pipes on site. The system 10 is assembled by an operator attaching, for example, detachably, a plurality of components necessary for sheet cleaning to the scaffold 20 . As shown in FIG. 21, the scaffolding 20 is equipped with a necessary plurality of scaffolding boards 22 .

<General Configuration of System 10>

As shown in FIG. 21, a sheet guide mechanism 30, a first removing device 32, a second removing device 34, a sheet collecting device 36, and the like are attached to the scaffolding 20 as a plurality of components necessary for sheet cleaning according to the present embodiment. The floor surface (including the ground) on which the scaffolding 20 contacts is covered with an air-impermeable sheet (floor surface curing sheet) so as not to be contaminated by substances generated by the current sheet cleaning method. These constituent elements will be described individually below.

<Sheet guide mechanism 30>

The sheet guide mechanism 30 is attached to the scaffolding 20 to guide the sheet SC to be cleaned SC in an unfolded state along a feeding path FP (e.g., the same trajectory drawn by the sheet to be cleaned SC when the sheet to be cleaned SC is fed).

<First removal device 32>

The first removing device 32 uses the first spray unit 40 to blow air onto the surface of the sheet to be cleaned SC in the first work space WS1 that is at least partially enclosed at the first position P1 on the feed path FP.

As a result, the first removing device 32 blows off the large size pieces of the coating film from the sheet to be cleaned SC and floats them in the air, thereby removing the large size pieces of the coating film from the sheet to be cleaned SC.

<Second removal device 34>

The second removing device 34 enables an operator to manually spray cleaning water at high pressure onto the surface of the sheet SC to be cleaned SC by using a high-pressure cleaning gun 42 to wash the sheet SC to be cleaned SC in the second work space WS2 at least partially enclosed at a second position P2 downstream of the first position P1 in the feed path FP.

As a result, the second removing device 34 separates the smaller ones of the plurality of coating film pieces and the release agent from the sheet SC to be cleaned SC by washing them away with the cleaning water in contact with them, and transports and drops the separated pieces by the cleaning water, thereby removing them from the sheet to be cleaned SC.

Further, after the sheet to be cleaned SC is washed, the second removing device 34 drains the water from the sheet to be cleaned SC by blowing air onto the surface of the sheet to be cleaned SC from the second injection unit 46 in the same second work space WS2.

<Sheet collecting device 36>

The sheet recovery device 36 is configured to recover the sheet to be cleaned SC as a sheet roll 50 by winding up the cleaned portion of the sheet to be cleaned SC on the most downstream side of the feed path FP.

In this embodiment, the handle 52 is rotated by the operator to manually rotate the winding core 54, and the cleaned portion of the sheet to be cleaned SC is wound therearound.

Alternatively, the sheet recovery device 36 may be configured to automatically wind up the sheet SC to be cleaned SC continuously or intermittently at an appropriate timing using a power source (for example, an electric motor) and, for example, remotely controlled by an operator.

<Seat cleaning method>

23A to 23C are process charts showing in chronological order an exemplary sheet cleaning method according to the present embodiment implemented using the system 10. FIG. Also, FIG. 24 is a diagram showing, in tabular form, correspondence relationships between a plurality of elements constituting the system 10 and a plurality of processes constituting this sheet cleaning method.

S1: Seat mounting process

As shown in FIG. 23, this sheet cleaning method has a sheet attachment step as step S1. The sheet attaching step S1 is a step in which an operator attaches the sheet to be cleaned SC to the sheet guide mechanism 30 in a horizontally unfolded state.

As shown in FIG. 24, this sheet attachment step S1 is performed using the sheet guide mechanism 30, but instead, the sheet guide mechanism 130 in the fifth embodiment, which will be described in detail later with reference to FIG. 31, may be used.

Since the sheet to be cleaned SC this time is the filter sheet 220 as described above, basically, the unnecessary substances mainly remain on one of the two surfaces (working surface) of the sheet to be cleaned SC.

Based on this, the sheet to be cleaned SC is attached to the sheet guide mechanism 30 with the working surface of the sheet to be cleaned SC facing downward, so that in the first removing step described later, an air blow is blown to the surface of the sheet to be cleaned SC opposite to the working surface, and then the air blow passes through a plurality of openings of the sheet to be cleaned SC (gaps between knitted yarns, gaps in fibers, etc.) and is discharged from the working surface.

As a result, in the first removing step S3, almost all of the unnecessary matter adhering to the sheet SC to be cleaned falls downward and is separated from the sheet SC to be cleaned SC by both the wind pressure of the air blow and gravity.

In this embodiment, the sheet SC to be cleaned SC is continuously or intermittently fed in the unfolded state within the system 10, but the term "unfolded state" throughout this application does not necessarily mean that the sheet SC to be cleaned SC is always in the unfolded state over its entire length. The term "developed state" means that it is sufficient for the sheet to be cleaned SC to be in the developed state in the cleaning processing section of the system 10, or more precisely, at least in the portion (region) where the sheet to be cleaned SC passes through the first removing device 32 and the second removing device 34, which will be described in detail later, and that the portion (region) in such the developed state may transition from the downstream side to the upstream side over the entire length of the sheet to be cleaned SC over time.

As shown in FIG. 21, the sheet to be cleaned SC has a pre-cleaning portion waiting before cleaning, i.e., a portion in which the sheet to be cleaned SC is folded and waited in the space on the upstream side of the sheet guide mechanism 30, and a collected portion in which the sheet to be cleaned SC is wound up and recovered after cleaning is present at the downstream side of the sheet to be cleaned SC, as shown in FIG.

S2: Sheet feeding process

As shown in FIG. 23, this sheet cleaning method further has a sheet feeding step as a subsequent step S2. This sheet feeding step S2 is a step of feeding the sheet to be cleaned SC in an unfolded state along the feeding path FP continuously or intermittently or in one direction or in both forward and reverse directions.

In this embodiment, the sheet to be cleaned SC is manually fed by an operator, but instead, it may be automatically fed using a power source by a sheet feeding device 132 as in a fifth embodiment described in detail later with reference to FIG.

S3: First removal step

As shown in FIG. 23, this sheet cleaning method further includes a first removal step as a subsequent step S3. The first removing step S3 is a step of separating and removing the large pieces of the plurality of coating film pieces by blowing an air blow onto the surface of the sheet to be cleaned SC in the first work space WS1.

As shown in FIG. 24, this first removal step S3 is performed using the first injection unit 40 (described later in detail) of the first removal device 32 . Further, the object to be removed from the sheet to be cleaned SC in the first removing step S3 is a piece of coating film having a large size or the like.

S4: Second removal step

As shown in FIG. 23, this sheet cleaning method further includes a second removal step as subsequent step S4. The second removing step S4 is a step of washing the sheet SC to be cleaned by spraying washing water at a high pressure onto the surface of the sheet SC to be cleaned in the second work space WS2, thereby separating and removing the coating film pieces having a small size among the plurality of coating film pieces and the release agent from the sheet SC to be cleaned.

As shown in FIG. 24, this second removal step S4 is performed using a high-pressure cleaning gun 42 (described later in detail) of the second removal device 34 . Objects to be removed from the sheet to be cleaned SC in the second removing step S4 include small-sized pieces of the coating film, release agents, and the like.

S5: Third removal step

As shown in FIG. 23, this sheet cleaning method further includes a third removal step as subsequent step S5. The third removing step S5 is a step of draining (for example, forced drying) the surface of the sheet SC to be cleaned SC by blowing an air blow onto the surface of the sheet SC to be cleaned in the second work space WS2.

As shown in FIG. 24, this third removal step S5 is performed using a second injection unit 46 (described later in detail) of the second removal device 34. As shown in FIG. In addition, the object to be removed from the sheet to be cleaned SC in this third removing step S5 is water or the like.

In the present embodiment, this third removing step S5 is performed in the same second work space WS2 together with the above-described second removing step S4. Alternatively, in the third work space WS3 located at a third position P3 on the downstream side of the second position P2 in the feed path FP, the surface of the sheet to be cleaned SC may be blown with an air blow to dry off the sheet to be cleaned SC.

S6: Sheet collection step

As shown in FIG. 23, this sheet cleaning method further has a sheet collecting step as a subsequent step S6. This sheet collection step S6 is a step of winding up the cleaned portion of the sheet to be cleaned SC and collecting it as a sheet roll 50 at a fourth position P4 downstream of the third position P3 in the feeding path FP.

As shown in FIG. 24, this sheet collecting step S6 is executed using a sheet collecting device 36 (described later in detail).

<Specific configuration of each component of system 10>

<Sheet guide mechanism 30>

As illustrated in FIGS. 25A and 25B, in one example, the sheet guide mechanism 30 includes a plurality of slide rings 60 (for example, carabiners) arranged discretely along both sides of the sheet SC to be cleaned SC and integrally moved along the sheet to be cleaned SC along the feed path FP; is configured to include

As illustrated in FIG. 21, a pair of guide wires 62 , 62 are fixedly installed on the scaffold 20 . As illustrated in FIGS. 25(a) and (b), each slide ring 60 is slidably coupled to a corresponding one of a pair of guide wires 62, 62 along its length.

As illustrated in FIGS. 25(a) and (b), in one example, the sheet to be cleaned SC has a plurality of eyelets 66 discretely arranged along both sides thereof. As is well known, the eyelets 66 are metal fittings (through-hole reinforcing tools) attached to the sheet to be cleaned SC for reinforcing the through holes 162 (see FIG. 31(b)) of the sheet to be cleaned SC.

As illustrated in FIGS. 25( a ) and 25 ( b ), each eyelet 66 (through hole 162 ) and the corresponding slide ring 60 are loosely attached and connected to the guide wire 62 so as to bundle the eyelet 66 and the guide wire 62 on the corresponding side. As a result, the sheet to be cleaned SC can be slidably moved in the feeding direction integrally with the slide ring 60 with respect to the guide wire 62 as a substantially stationary member.

The sheet to be cleaned SC is connected to a pair of guide wires 62, 62 at both ends in the width direction thereof, and thereby suspended from the pair of guide wires 62, 62 in a state of supporting both ends. At this time, as illustrated in FIG. 21, the sheet to be cleaned SC is suspended in contact (slidable contact) with a sheet supporting surface substantially continuous along the feeding path FP, which is composed of a plurality of members including the first and second mesh plates 72 and 116 (for example, a plurality of plate-like members arranged in a row along the feeding path FP), or is suspended in a state of floating therefrom without contacting the sheet supporting surface.

As illustrated in FIGS. 25(a) and 25(b), in the present embodiment, a plurality of eyelets 66 are attached along the width direction to the front end portion of both ends of the sheet to be cleaned SC in the length direction. A pull-out rope 70 is detachably attached to at least one of the eyelets 66 as an example of a pulling tool for manually pulling the sheet to be cleaned SC in the feed direction.

In this example, the operator can manually feed the sheet to be cleaned SC in its length direction using the pull-out rope 70 in the first stage before the leading edge of the sheet to be cleaned SC reaches the sheet recovery device 36, and can feed the sheet to be cleaned SC by manually or automatically winding it up using the sheet recovery device 36 in the second stage after the leading edge of the sheet to be cleaned SC reaches the sheet recovery device 36.

<First removal device 32>

<First mesh plate 72>

As shown in FIG. 21, the first removing device 32 has a first mesh plate 72 that faces the lower surface (the working surface described above) of the sheet to be cleaned SC in a non-contact state and generally parallel thereto.

The first mesh plate 72 has a mesh shape in a plan view, and the material thereof is expanded metal (for example, a mesh-shaped member obtained by expanding a metal plate while making cuts in a staggered manner using an expander, and forming the cuts into a rhombus or tortoiseshell shape). The first mesh plate 72 is attached and fixed to the scaffolding 20 .

Each opening of the first mesh plate 72 has a size that allows, for example, when a large piece of coating film adhering to the sheet SC to be cleaned falls from the sheet SC to be cleaned, the piece of coating film can pass through each opening of the first mesh plate 72.

<Paint film piece collection sheet assembly>

As shown in FIG. 21, the first removal device 32 further includes a generally hexahedral coating film piece collection sheet assembly 74 for collecting large pieces (e.g., floating particles, floating bodies) among the plurality of coating film pieces separated from the sheet to be cleaned SC by the air blow.

A first working space WS1 is defined inside the coating film piece collecting sheet assembly 74. As shown in FIG. As shown in FIG. 26(a), the coating film piece recovery sheet assembly 74 completely surrounds the hexahedral first work space WS1, and thus constitutes an example of a "first enclosure".

As shown in FIG. 4(a), the coating film piece recovery sheet assembly 74 is formed by folding a plurality of sheets or detachably joining them together using a fastener or the like, so as to surround the first work space WS1 from all directions.

As shown in FIG. 4(a), the coating film piece collecting sheet assembly 74 is divided into an upper body 76 and a lower body 78 with the feeding path FP as a boundary.

The upper body 76 is composed of a top plate 80, a front plate 82, a rear plate 84 and left and right side plates 86, 86, and does not have a bottom plate. On the other hand, the lower body 78 is composed of a bottom plate 90, a front plate 92, a rear plate 94 and left and right side plates 96, 96, and does not have a top plate. This paint film collecting sheet assembly 74 is positioned with respect to the scaffold 20 so that the bottom surface (non-existent surface) of the upper body 76 is arranged below the feed path FP.

In the upper body 76, the top plate 80, the front plate 82, the rear plate 84 and the left and right side plates 86, 86 are all constructed as flexible sheets.

Of these plates, the front plate 82, the rear plate 84, and the left and right side plates 86, 86 are all constructed as air-impermeable sheets in order to prevent a plurality of coating film pieces floating in the first work space WS1 from scattering outside the first work space WS1 due to the air blown onto the sheet to be cleaned SC in the first removing step S3. The front plate 82, the rear plate 84, and the left and right side plates 86, 86 are all examples of "anti-scattering means."

On the other hand, the top plate 80 is configured as a (porous) mesh sheet having a plurality of openings in order to allow the air blow to dissipate into the outside air, that is, to allow gas venting.

On the other hand, in the lower body 78, the bottom plate 90, the front plate 92, the rear plate 94, and the left and right side plates 96, 96 are all constructed as flexible sheets.

Of these plates, the front plate 92, the rear plate 94, and the left and right side plates 96, 96 are made of air-impermeable sheets in order to prevent the plurality of floating coating film pieces from scattering outside the first work space WS1.

Most of the plurality of coating film pieces separated from the sheet to be cleaned SC fall directly from the sheet to be cleaned SC by their own weight and land on the bottom plate 90, or even if they are a small number, they float and then fall by their own weight and land on the bottom plate 90, and in any case finally land on the bottom plate 90 and accumulate. Therefore, the bottom plate 90 is also made of an air-impermeable sheet.

As shown in FIG. 8A, the horizontal belt-shaped lower end of the front plate 82 of the upper body 76 is partially cut into a horizontally elongated flap shape, thereby functioning as an entrance opening/closing door 100. Similarly, the horizontal belt-shaped lower end of the rear plate 84 of the upper body 76 functions as an exit opening/closing door 102. Here, the "opening/closing door" is a movable piece that can be identified with, for example, noren, curtains, and bamboo blinds.

In the front plate 82, a horizontal bending line BL is formed as a hinge between the entrance opening/closing door 100 and a portion above it, thereby facilitating the bending of the entrance opening/closing door 100 with respect to the portion above it with the bending line BL as a starting point in response to an external force.

Specifically, as shown in FIG. 4B, the entrance opening/closing door 100 is always in a closed state in which it hangs down due to its own weight and closes the front plate 82, thereby closing the first work space WS1.

On the other hand, when the sheet to be cleaned SC approaches the outer surface of the entrance opening/closing door 100 from the upstream side and the downstream end of the sheet to be cleaned SC eventually contacts the outer surface of the entrance opening/closing door 100, the entrance opening/closing door 100 is bent by the forward force of the sheet to be cleaned SC, and as a result, the front plate 82 is shifted to an open state in which the front plate 82 is partially opened.

At this time, since the lower end of the entrance opening/closing door 100 contacts the surface of the sheet to be cleaned SC, the entrance opening/closing door 100 is bent only at an angle sufficient to allow the passage of the sheet to be cleaned SC, and the opening of the front plate 82 with a uselessly wide area and an unnecessarily long time is suppressed.

Similarly, the exit opening/closing door 102 is always in a closed state in which it hangs down due to its own weight and closes the rear plate 84, thereby closing the first work space WS1.

On the other hand, when the sheet to be cleaned SC approaches the inner side surface of the outlet opening/closing door 102 from the upstream side and the downstream end of the sheet to be cleaned SC eventually contacts the inner side surface of the outlet opening/closing door 102, the advancing force of the sheet to be cleaned SC bends the outlet opening/closing door 102 starting from the bending line BL, and as a result, the rear plate 84 is shifted to an open state in which the rear plate 84 is partially opened.

At this time, since the lower end of the outlet opening/closing door 102 contacts the surface of the sheet to be cleaned SC, the outlet opening/closing door 102 is bent only at an angle sufficient to allow the passage of the sheet to be cleaned SC, and the rear plate 84 is prevented from being opened in a wastefully wide area and in a wastefully long time.

As shown in FIG. 1, when the sheet to be cleaned SC passes through the coating film piece collecting sheet assembly 74 in the feed direction, both the entrance opening/closing door 100 and the exit opening/closing door 102 are open with respect to the sheet to be cleaned SC.

Therefore, the plurality of floating coating film pieces are prevented from passing through the opening areas of the entrance opening/closing door 100 and the exit opening/closing door 102 and leaking out to the outside air.

This coating film piece collecting sheet assembly 74 is discarded after use, for example.

<First injection unit 40>

As shown in FIG. 21, the first removal device 32 further includes a dry first injection unit 40 that injects compressed gas toward the sheet to be cleaned SC. As shown in FIGS. 21 and 27, the first injection unit 40 has a frame-like body formed by connecting a plurality of tubes 104 with a plurality of joints 106. As shown in FIG.

The tube 104 and the joint 106 cooperate with each other to form a continuous flow path, to which an external air pressure source 108 is connected via a hose (not shown). A nozzle 110 is connected downward to each joint 106, and an air blow is jetted from the nozzle 110 in a conical or fan shape.

As shown in FIGS. 21 and 27, the first injection unit 40 has two straight portions 112, 112 facing each other in parallel, and a plurality of nozzles 110 are linearly arranged on each of the straight portions 112 with a gap therebetween. As a result, the first injection unit 40 has a plurality of nozzles 110 for two rows.

As shown in FIG. 21, the first injection unit 40 is detachably mounted across the scaffolding 20 such that it crosses the feed path FP above the feed path FP (above the sheet to be cleaned SC) and two nozzle rows jet air blow downward.

<Second removal device 34>

<Second mesh plate 116>

As shown in FIG. 21, the second removing device 34 has a second mesh plate 116 that faces the lower surface (the working surface described above) of the sheet SC to be cleaned SC in a non-contact and generally parallel manner. The second mesh plate 116 has a mesh shape in a plan view, and its material is reinforced mesh. This second mesh plate 116 is also attached and fixed to the scaffolding 20 in the same manner as the first mesh plate 72 .

Each opening of the second mesh plate 116 has a size that allows, for example, when a small-sized coating film piece adhering to the sheet SC to be cleaned falls from the sheet SC to be cleaned, the coating film piece passes through each opening of the second mesh plate 116. Each opening of the second mesh plate 116 may be smaller than each opening of the first mesh plate 72, for example.

<Washing Water Collection Sheet Assembly 118>

As shown in FIG. 21, the second removal device 34 further includes a cleaning water collecting sheet assembly 118 having a generally C-shaped cross-section extending back and forth in order to collect small pieces of the plurality of coating film pieces separated from the sheet to be cleaned SC by collision with the cleaning water and those carrying the release agent.

A second work space WS2 is defined inside the cleaning water collecting sheet assembly 118 . As shown in FIG. 28, the cleaning water collecting sheet assembly 118 partially surrounds the hexahedral second work space WS2, that is, the left and right side surfaces and the bottom surface as three surfaces excluding the top surface, the front surface, and the rear surface (none of which actually exists), thereby forming an example of a “second enclosure”.

As shown in the figure, the cleaning water collecting sheet assembly 118 is three-dimensionalized so as to surround the second work space WS2 from three directions by folding a plurality of sheets or detachably joining them together using fasteners or the like.

As shown in the figure, the cleaning water collecting sheet assembly 118 is composed of left and right side plates 120, 120 and a bottom plate 122, and does not have a top plate, a front plate, or a rear plate. This cleaning water collecting sheet assembly 118 is positioned with respect to the scaffolding 20 such that the bottom plate 122 is positioned below the feed path FP. Both the left and right side plates 120, 120 and the bottom plate 122 are constructed as flexible sheets.

The front surface of the cleaning water collecting sheet assembly 118 faces and adjoins the rear plate 84 of the upper body 76 of the coating strip collecting sheet assembly 74 along the feeding direction. At this time, the lower end position of the front surface and the lower end position of the rear plate 84 are substantially aligned in the horizontal direction. Thus, the cleaning water collection sheet assembly 118 is fluidly isolated from the coating strip recovery sheet assembly 74 by the rear plate 84 of the coating strip recovery sheet assembly 74 .

When the cleaning water collecting sheet assembly 118 is adjacent to the coating strip recovery sheet assembly 74 in the feeding direction, and there must be a large gap between the two to the extent that harmful substances are expected to leak out, a seal member for closing the gap is installed across the cleaning water collecting sheet assembly 118 and the coating strip recovery sheet assembly 74.

The seal member is configured, for example, as a cross member with a horizontal surface below it so as not to obstruct the feed path FP. As a result, the feeding path FP is substantially continuous from the coating film piece collecting sheet assembly 74 to the cleaning water collecting sheet assembly 118 without any gap.

In the second work space WS2, the high-pressure cleaning gun 42 jets cleaning water from the high-pressure cleaning gun 42 by the second removing device 34, targeting the entire sheet SC to be cleaned or a portion requiring cleaning, and collides with the target. The washing water that has collided carries the coating film pieces that are larger in size among the plurality of coating film pieces and the release agent that is generated by the collision.

The washing water as the conveying medium is expected to pass directly through the through holes of the sheet to be cleaned SC (the through holes of the eyelets 66) and drop, or bounce back and float on the sheet to be cleaned SC, eventually drop by its own weight, and then pass through the through holes of the sheet to be cleaned SC and drop. In any case, when the washing water (used washing water that has fulfilled the mission of separating and peeling from the sheet SC to be washed) affected by the unnecessary matter on the sheet SC to be washed falls, the washing water finally lands on the bottom plate 122 of the water collecting sheet assembly 118 for washing.

The bottom plate 122 is mortar-shaped and generally has an inverted pyramidal or inverted cone shape that depends most at its generally centrally located wastewater outlet 124 . As a result, no matter where the used wash water lands on the bottom plate 122 , it will eventually collect at the waste water outlet 124 due to its own weight and the action of the slope of the bottom plate 122 .

This cleaning water collecting sheet assembly 118 is also discarded after use, for example, in the same manner as the coating film piece collecting sheet assembly 74 described above.

<High pressure cleaning gun 42>

As shown in FIG. 21, the second removal device 34 further includes a high-pressure cleaning gun 42 as an example of a "high-pressure injector" for manually injecting cleaning water at high pressure toward the sheet SC to be cleaned by an operator.

The high-pressure cleaning gun 42 may have a structure common to that of the cleaning gun 216 disclosed in Patent Document 3, and is configured to inject cleaning water at high pressure from an injection nozzle.

In one example, the high-pressure cleaning gun 42, like the cleaning gun 216, is configured to include a trigger as an operation tool operated by one hand of the operator, and a flow control valve for turning on/off the high-pressure cleaning gun 42 and adjusting the flow rate according to the amount of operation of the trigger. The injection nozzles are selected, for example, to perform conical injection or fan-shaped injection (see FIG. 27(c)).

<Second injection unit 46>

As shown in FIG. 21, the second removal device 34 further includes a dry second injection unit 46 that injects compressed gas toward the sheet to be cleaned SC. Since the second injection unit 46 has a structure common to that of the first injection unit 40 described above, redundant description will be omitted.

As shown in FIG. 21, the second injection unit 46 is detachably mounted across the scaffold 20 such that it traverses the feed path FP above the feed path FP (above the sheet to be cleaned SC), two nozzle rows eject air blows downward, and each nozzle row extends in the width direction of the feed path FP.

As described above, the second jetting unit 46 has the same structure as the first jetting unit 40, but differs from the first jetting unit 40 in that after the sheet SC is washed with water, the sheet to be cleaned SC is drained by blowing an air blow onto the sheet to be cleaned SC in the second work space WS2, thereby separating and removing large-sized pieces of the coating film from the sheet to be cleaned SC.

<Work floor 126>

As shown in FIG. 21, the second removing device 34 further has a working floor 126 as a scaffold board for the operator to perform high-pressure cleaning work in the second working space WS2 in an upright posture. As shown in FIG. 29, in one example, the working floor 126 is constructed as a longitudinal hollow assembly of a plurality of rectangular timbers, angle timbers, etc., and a mesh plate 128 is attached to the surface thereof. The mesh plate 128 is manufactured using, for example, the expanded metal described above.

As shown in FIG. 21, the work floor 126 is detachably laid across the scaffold 20 above the second injection unit 46 and across the feed path FP.

FIG. 30 is a front view showing the second removal device 34 with several filters attached to it.

In the second work space WS2, at the installation position of the work floor 126, the work floor 126, the sheet to be cleaned SC that is laid across the pair of guide wires 62, 62 in an unfolded state, the second mesh plate 116, the support member (e.g., horizontal bar) 136, and the bottom plate 122 of the water collecting sheet assembly 118 are arranged in order from the top.

The used wash water flowing out from the sheet to be washed SC lands on the bottom plate 122, flows down along the bottom plate 122, collects at the waste water outlet 124, and then passes through the drain pipe 138 and is transferred to equipment for the aggregation process. In one example, the equipment for the coagulation step is configured such that a primary coagulation filter tank 140 and a secondary coagulation filter tank 142 are connected in series.

[Fifth embodiment]

A fifth exemplary embodiment of the present invention will now be described. However, elements common to those of the above-described fourth embodiment will be referred to with the same reference numerals to omit redundant description, and only different elements will be described in detail.

<Difference from the fourth embodiment>

In the above-described fourth embodiment, the sheet to be cleaned SC is manually fed by the operator along the feed path FP while being guided by the sheet guide mechanism 30 .

On the other hand, in the sheet cleaning system 148 according to the present embodiment, the sheet to be cleaned SC is automatically fed along the feeding path FP using the sheet feeding device 132 having a power source (in some cases, according to remote control by the operator). Therefore, according to this embodiment, it is possible to unmanned the work of feeding the sheet to be cleaned SC.

Furthermore, in the above-described fourth embodiment, the high-pressure cleaning gun 42 is manually sprayed onto the surface of the sheet SC to be cleaned by the operator.

On the other hand, in the system 148 according to the present embodiment, the high-pressure injector 152 automatically (in some cases, according to remote control by the operator) sprays the cleaning water onto the surface of the sheet SC to be cleaned using the injector moving device 150 having a power source. Therefore, according to the present embodiment, it is possible to unmann the high-pressure cleaning work of the sheet to be cleaned SC.

<Unmanned and automated sheet feeding>

As shown in FIG. 31(a), a system 148 according to the present embodiment additionally includes a sheet feeding device 132, which does not exist in the fourth embodiment, and a sheet guide mechanism 130 having a different structure, in order to automate the feeding of the sheet to be cleaned SC.

In short, this embodiment is different from the fourth embodiment in that it is provided with a transmission device for transmitting the rotational force of the motor as the power source to the sheet SC to be cleaned SC as a driving force along the feed direction thereof.

<Sheet guide mechanism 130>

As shown in FIG. 4A, the sheet guide mechanism 130 includes two conveyor belts 154, 154 extending in the feed direction, each of which is an example of an "endless track". The two series of conveyor belts 154, 154 are operated synchronously with each other.

The sheet guide mechanism 130 further includes a pulley set consisting of a driving pulley (an example of a "driving rotor") 156 and a driven pulley (an example of a "driven rotor") 158 around which each conveyor belt 154 is wound in tension. The drive pulley 156 and the driven pulley 158 are positioned and mounted on the scaffold 20 so as to be spaced from each other in the feeding direction.

The two conveyor belts 154, 154 are arranged relative to the sheet to be cleaned SC so as to face both sides of the sheet to be cleaned SC from below (or above). As shown in FIG. 4B, a plurality of protrusions (engagement protrusions, protrusions, etc.) 160 are discretely arranged in a line on the surface of each conveyor belt 154 . The protrusions 160 are fitted into a plurality of through holes 162 (grommets 66) discretely arranged in a line on each side of the sheet SC to be cleaned.

Therefore, when each projection 160 is fitted in the corresponding through hole 162, the sheet to be cleaned SC does not move with respect to the scaffolding 20 either in the feed direction or in the lateral direction. Therefore, in this embodiment, the sheet guide mechanism 130 is configured by the two conveyor belts 154, 154 and the pulley set in a manner that utilizes the plurality of through holes 162 of the sheet to be cleaned SC as in the sheet guide mechanism 130 in the fourth embodiment.

<Sheet feeding device 132>

As shown in FIG. 4A, the sheet feeder 132 includes a motor 164 as a power source, a speed reducer 166, and a shaft 168 as a member for transmitting the output of the speed reducer 166 to the drive pulley 156 as rotational force. Motor 164 is driven by electrical energy from a power supply (not shown). This motor 164 can be started/stopped, reversed, and accelerated/decelerated in accordance with instructions from the operator.

<Automation of high-pressure injection>

As shown in FIG. 32(a), the system 148 according to the present embodiment includes an injector moving device 150 that uses a power source to automatically inject cleaning water from a high pressure injector 152 toward the sheet SC to be cleaned SC at high pressure and move it in the width direction of the sheet SC to be cleaned, in order to automate the high pressure cleaning of the sheet SC to be cleaned.

<Injector moving device 150>

As shown in FIG. 1(a), the injector moving device 150 comprises a high pressure injector 152 having an injection nozzle 170. As shown in FIG. The high pressure injector 152 is connected to an external water pressure source 174 via a flexible hose 172 .

The injector moving device 150 further includes a base support 176, which is detachably laid across the scaffold 20 so as to be placed at a predetermined position in the second work space WS2 in a posture that traverses the sheet to be cleaned SC.

The injector moving device 150 further comprises a linear guide 178 for slidably mounting the high pressure injector 152 on the base support 176, as shown in FIG. The linear guide 178 includes a rail 180 linearly extending in the width direction (horizontal direction) of the sheet to be cleaned SC and a slider 182 slidably fitted to the rail 180 on the base support 176 . The slider 182 moves integrally with the high pressure injector 152 . Here, the rail 180 is an example of a "track", and the linear guide 178 is an example of a "coupling mechanism".

The injector moving device 150 further includes an injector propulsion device 184, as shown in FIG. The injector propulsion device 184 has a motor 186 as a power source and a conversion mechanism 188 that converts the output of the 186 motor into the propulsion force of the high pressure injector 152 . One example of motor 186 is an electric motor.

An example of conversion mechanism 188 is a mechanism that converts rotation of motor 186 into rotation of endless belt 190 and imparts the thrust of straight portion 196 of belt 190 to high pressure injector 152 . In this example, the belt 190 is wrapped around a drive pulley 192 and a driven pulley 194 spaced apart in the direction of movement of the high pressure injector 152, and one of the two straight sections 196, 196 of the belt 190 and the high pressure injector 152 are mechanically associated with each other.

In this embodiment, in one example, the controller 204 can control the motor 186 to advance, stop, or reverse the high pressure injector 152 laterally, and control the flow control mechanism of the high pressure injector 152, thereby controlling the injection volume of the high pressure injector 152, according to real-time or pre-programmed instructions issued by an operator on site. In this case, the controller 204 can scan the entire surface of the sheet to be cleaned SC by reciprocating the high-pressure injector 152 and control the injection amount of the high-pressure injector 152 according to the position of the high-pressure injector 152 at each instant.

In one example, the controller 204 can move the high pressure injector 152 in the left-right direction to a target position and stop, and at the stop position, the high pressure injector 152 can inject at a target injection amount for a target time. In this case, one target area of the sheet to be cleaned SC can be locally high-pressure washed, or a plurality of target areas of the cleaning sheet can be locally high-pressure washed one after another.

[Sixth embodiment]

An exemplary sixth embodiment of the present invention will now be described. However, the same reference numerals are used for elements that are common to the above-described fourth embodiment to omit redundant description, and only different elements will be described in detail.

FIG. 33 shows, in tabular form, the correspondence relationship between a plurality of steps constituting the sheet cleaning method according to this embodiment and a plurality of elements constituting a sheet cleaning system used for carrying out the sheet cleaning method.

<Difference from the fourth embodiment>

This embodiment differs from the above-described fourth embodiment in the following points.

1. As shown in tabular form at the top of FIG. 33, the third removing step S5 is performed independently of the second removing step S4 in the third workspace WS3 located at the third position P3 downstream of the second position P2 in the feed path FP.

2. As shown in the figure, a new fourth removing step S6 uses a fourth removing device 206 in a fourth work space WS4 located at a fourth position P4 on the downstream side of the third position P3 in the feed path FP, and after the sheet to be cleaned SC has been drained, the sheet to be cleaned SC is struck out with a brush and/or sucked with a suction tool.

According to this fourth removing step S6, it is possible to remove from the sheet SC to be cleaned fine coating film pieces and sharp coating film pieces that have adhered to or entangled with the fibers of the sheet SC to be cleaned and which could not be separated and removed from the sheet SC to be cleaned in the processes carried out further upstream, by the impact force of the brush or the suction force of the suction tool.

In one example, the fourth removal device 206 is configured to include a motor-driven rotating brush device used in a vacuum cleaner head, as conceptually represented in the functional block diagram at the bottom of the figure. The motor-driven rotary brush device is configured to include a motor 207, a brush 208 that is rotated (for example, rotates) by the motor 207, and an air pump 209 (an example of a "suction tool") that sucks coating film pieces (solids) from the sheet SC to be cleaned SC while striking them with the rotating brush 207.

In some of the embodiments described above, the first removing device 32 and the second removing device 34 of each sheet cleaning system 10, 148 are fixed in space when viewed from the side, while the sheet to be cleaned SC is moved with respect to the space when viewed from the side, thereby achieving relative movement between them in the feeding direction.

Instead of the several embodiments described above, the present invention may be implemented in such a manner that the first removing device 32 and the second removing device 34 of each sheet cleaning system 10, 148 are moved with respect to the space when viewed from the side, while the sheet to be cleaned SC is fixed in the space when viewed from the side, thereby realizing relative movement between them in the feed direction.

In this aspect, when the first removal device 32 and the second removal device 34 each have equipment that is common in construction (e.g., the first injection unit 40 and the second injection unit 46), one piece of equipment may be used to perform the first removal step S3 and the second removal step S4. In that case, the number of parts for each sheet cleaning system 10, 148 is reduced.

As described above, some embodiments in the case of applying the present invention to the application of washing used sheets used in wastewater treatment for wet coating stripping work have been described, but these are examples, and the present invention can be applied to other applications, such as buildings (houses, buildings, etc.), steel towers that are long and thin structures that are constructed using a steel frame structure (e.g., power transmission towers, communication towers, etc.), civil engineering structures (bridges, etc.), ships, vehicles (automobiles, trains, etc.) without using a stripping agent. It is possible to apply it to the application of washing used sheets used for washing the surfaces of structures such as airplanes or the like, and waste water that may contain harmful substances is generated during the work.

As described above, some exemplary embodiments of the present invention have been described in detail based on the drawings, but these are examples, and the present invention can be implemented in other forms with various modifications and improvements based on the knowledge of those skilled in the art, including the embodiments described in the section [Summary of the Invention].

Claims (7)

A wastewater treatment system for recovering and treating washing water sprayed onto a surface of a structure as wastewater after its use, comprising:
a flocculating device for flocculating target substances in the wastewater as flocculated flocs using a powdery or granular flocculant added to the wastewater;
The flocculator is
a coagulation tank containing the wastewater;
two first stirring shafts arranged in parallel with a substantially vertically extending longitudinal gap in the flocculation tank;
a driving source that rotates the first stirring shafts so that the corresponding two or two groups of first stirring blades rotate in the same direction, thereby generating a downward vortex in or around a portion of the wastewater corresponding to the gap in the flocculation tank so as to have a depression that opens to the liquid surface of the wastewater;
A wastewater treatment system comprising: a dosing device that accommodates the flocculant and has a flocculant feeding start area facing the liquid surface, and capable of feeding the flocculant into the wastewater from the feeding start area; the flocculation device further comprising at least one second agitating shaft attached to the flocculation vessel;
2. The wastewater treatment system of claim 1, wherein the at least one second agitating shaft rotates a respective at least one second agitating impeller, thereby dispersing flocculant entrained by the vortex within the wastewater. Two or two groups of first stirring blades corresponding to the two first stirring shafts, respectively, include an upper stirring blade arranged at a position close to the liquid surface of the wastewater in the flocculation tank,
2. The wastewater treatment system according to claim 1, wherein the upper agitating blade is attached to the corresponding agitating shaft so as to be axially position-adjustable in the assembled state of the agitating shaft, so that the vertical distance from the liquid surface is adjustable. Two or two groups of first stirring blades corresponding to the two first stirring shafts, respectively, include a lower stirring blade arranged near the bottom of the aggregation tank,
2. The wastewater treatment system of claim 1, wherein the lower impeller is used for at least one of the following purposes: to assist in accelerating the flocculant entrained by the vortex to facilitate diffusion of the flocculant; The aggregating device further comprises:
a drain formed at the bottom of the aggregation tank;
a filter bag installed in the coagulation tank, which filters the wastewater in the process of draining the wastewater injected into the filter bag from the drain;
The wastewater treatment system according to claim 1, further comprising: a spacer installed between the bottom of the filter bag and the drain, wherein a gap is formed between the bottom of the filter bag and the drain so that at least a liquid component of the wastewater can pass through the gap, thereby preventing clogging of the drain. 2. The wastewater treatment system according to claim 1, wherein the wastewater treatment system is used for recovering and treating the washing water sprayed on the surface of the structure for washing the surface of the structure after the remover has been applied to the surface of the structure in order to remove the existing paint film from the surface of the structure using the remover, as wastewater after its use. 7. The wastewater treatment system of claim 6, wherein said target material is selected from the group consisting of lead, chromium, asbestos and PCB.

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