JP2799838B2 - Mud water treatment device and mud water treatment method using the device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a muddy water separating apparatus, and more particularly to a muddy water separating apparatus used in a muddy water method in which an excavator uses a muddy water to excavate.

[0002]

2. Description of the Related Art Conventionally, in a muddy water method in which excavation is performed by using an excavator using muddy water, a muddy water treatment facility that collects excavated earth and sand from muddy water discharged from the excavator and reuses the collected muddy water. It has been known. FIG. 17 is a schematic diagram showing a configuration of a conventional muddy water treatment facility. Referring to FIG. 17, a conventional muddy water treatment facility includes an excavator 10
A muddy water treatment device 10 that receives the collected muddy water collected from 1 and collects gravel, sand, and fine particles of 74 μm or more, and a collected muddy water containing silt and clay of 74 μm or less after being processed by the muddy water treatment device 10. The collected mud after the specific gravity adjustment is supplied to the excavator 101 again and the collected mud which is not reused is discharged.
Fresh water is supplied to the collected mud containing silt and clay of μm or less, and a fresh water tank 106 for adjusting the specific gravity thereof, and the collected mud containing silt and clay of 74 μm or less discharged from the adjusting tank 105 and not reused are supplied. Waste mud tank 107 for storage and 74 μm stored in waste mud tank 107
a separation device 300 for separating collected mud containing silt and clay of m or less into solids and liquid, and a PH neutralization device 40 for neutralizing the PH of the water separated by the separation device 300. .

The muddy water treatment apparatus 10 includes a cyclone 13 for classifying collected muddy water collected from the excavator 101 into gravels having a particle diameter of 74 μm or more, silts having a particle diameter of 74 μm or less, a cyclone 13, and the like. First, gravel and the like having a large particle size of 200 μm or more are collected from the collected mud from the machine 101, and the remaining collected mud is discharged and gravel and the like having a particle size of 74 μm or more classified by the cyclone 13 are collected. A screen 11 for classifying gravel and the like from collected mud containing
The collected mud discharged when collecting gravel or the like having a particle size of 000 μm or more is stored.
A lower tank 12 for supplying the collected muddy water containing gravels having a particle size of μm or less to the cyclone 13, and gravels and sand of 74 μm or more collected by the screen 11 were provided on a transport vehicle 104. And a conveyor 102 for transporting to the hopper 103.

[0004] The separating device 300 includes a flocculant supply device 31 for supplying a flocculant to the collected mud containing silt and clay having a particle size of 74 µm or less stored in the waste mud tank 107, and a flocculant supply device 31. A filter press 302 that separates the collected mud supplied with the coagulant into water and solids such as silt / clay to collect a silt / clay of 74 μm or less, and a silt of 74 μm or less collected by the filter press 302・ Conveyor 102 for clay etc.
And a conveyer 33 for transporting the sheet.

The pH neutralizer 40 adjusts the pH by adding diluted sulfuric acid or the like to alkaline water separated by the filter press 302 of the separator 300.

Next, FIG. 18 is a diagram showing the composition of muddy water for explaining the muddy water treatment method using the conventional muddy water treatment equipment shown in FIG.

Referring to FIG. 18, the composition of mud collected from excavator 101 is clay having a particle diameter of 5 μm or less, silt having a particle diameter of 5 μm to 74 μm, 7
Fine sand having a particle size of 4 μm to 420 μm, 420 μm to
Coarse sand having a particle size of 2000 μm, 2000 μm-47
Gravel with a particle size of 60 μm and gravel with a particle size of 4760 μm or more can be classified.

[0008] Of the recovered mud having such a composition,
In the conventional muddy water treatment equipment, fine sand, gravel, and the like having a particle size of 74 μm or less are collected by the muddy water treatment device 10, and are collected by the muddy water treatment device.
A two-stage recovery method of recovering silt, clay, and the like having a size of m or less by the separation device 300 is employed.

Next, the muddy water treatment operation of the conventional muddy water treatment equipment will be described with reference to FIG. 17 again. First,
The collected mud collected from the excavator 101 is supplied to the screen 11 of the muddy water treatment device 10. On the screen 11, first, gravels or the like having a size of 2000 μm or more are collected using vibration, and the remaining collected mud is discharged to the lower tank 12. The collected mud containing the gravel and the like having a particle size of 2000 μm or less by the lower tank
Supplied to Classification with a particle diameter of 74 μm is performed by the cyclone 13, and the collected muddy water containing gravel and the like having a particle diameter of 74 μm or more is supplied to the screen 11 again. Thus, gravel or the like having a particle size of 74 μm or more is collected by the screen 11.

[0010] The collected gravel and the like are transported to a hopper 103 by a conveyor 102 and further loaded on a transport vehicle 104 arranged below the hopper 103.

74 μ classified by cyclone 13
The collected mud containing silt or the like having a particle size of m or less is supplied to the adjusting tank 105 and stored. In the adjusting tank 105, the specific gravity of the collected mud is measured, and the fresh water tank 106 is adjusted to have a specific gravity (about 1.1) suitable for reuse in excavation.
And the collected mud is discharged from the adjusting tank 105.

[0012] Here, 74 which passed through the muddy water treatment device 10
The specific gravity of the collected mud water containing silt or the like having a particle size of μm or less is about 1.25, and a large amount of fresh water is supplied from the fresh water tank 106 to adjust the specific gravity to 1.1. A large amount of collected mud is discharged.

The collected mud containing silt / clay having a particle size of 74 μm or less discharged from the adjusting tank 105 is supplied to the waste mud tank 1
07. The collected muddy water is supplied from the waste muddy water tank 107 to the filter press 302 by a pump. At this time, the collected mud supplied to the filter press 302 is coagulated by the coagulant supplied from the coagulant supply device 31. Thereafter, the solid 62 having a particle size of 74 μm or less, such as silt or clay, and water 6 are filtered by a filter press 302.
And 1. After that, the solid objects 62 such as silt and clay are transported to the conveyor 102 by the conveyor 33. The water separated by the filter press 302
Since it has alkalinity, it is supplied to the PH neutralization device 40 and neutralized with dilute sulfuric acid or the like, and then discharged.

[0014]

However, the muddy water treatment apparatus used in the above-mentioned muddy water treatment equipment has the following problems.

The screen used in this muddy water treatment apparatus needs to be vibrated at a high speed in order to separate gravels of 2000 μm or more from the collected muddy water. For this reason, since noise is generated and the ground vibrates violently, it is necessary to provide a vibration isolator or a sound proof device. Particularly in urban areas, even if these soundproofing and vibration-proofing measures are taken, they cannot be used gradually due to complaints from local residents.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a muddy water treatment apparatus which has low vibration and low noise and which is downsized.

[0017]

SUMMARY OF THE INVENTION A muddy water treatment apparatus according to the present invention has openings at both ends so that one end side forms an inlet area and the other end side forms an outlet area, and is rotatable about an axis. And a substantially cylindrical first rotating screen made of a wire mesh having a predetermined mesh size;
Inside the rotating screen, the mesh is arranged so as to be rotatable about the axis, has openings in the inlet area and the outlet area, and is smaller than the mesh of the wire mesh of the first rotating screen. A substantially cylindrical second rotating screen made of a wire mesh having a size.

Preferably, the first rotating screen and the second rotating screen are rotatable in the same direction.

More preferably, the first rotating screen and the second rotating screen are rotatable in different directions.

[0020] More preferably, the second rotating screen is provided so that the opening in the outlet area is smaller than the opening in the inlet area.

[0021] More preferably, a generatrix located at the lowermost end of the first rotating screen descends from the entrance area to the exit area.

More preferably, a generatrix located at the lowermost end of the second rotating screen rises from the entrance area to the exit area.

More preferably, a plurality of the second rotating screens are arranged in the axial direction inside the first rotating screen.

[0024] More preferably, an inner surface of the second rotating screen has a partition plate extending spirally from the entrance area to the exit area.

[0025] More preferably, the inner surface of the first rotary screen has a partition plate spirally extending from the entrance area to the exit area.

More preferably, a wedge wire is used for the first rotating screen, and in a plane facing the axial direction of a wire constituting the wedge wire extending in the axial direction, a rotational direction about the axis of the plane is used as a center. The first inscribed circle defined by the front end as seen in FIG. 2 is smaller than the second inscribed circle defined by the rear end, and the wedge shape is formed by the first inscribed circle and the plane. Is formed.

More preferably, a wedge wire is used for the first rotating screen, and in a plane facing the axial direction of a wire constituting the wedge wire extending in the axial direction, a rotational direction about the axis of the plane is used as a center. The first inscribed circle defined by the front end as seen in FIG. 2 is larger than the second inscribed circle defined by the rear end, and the wedge shape is formed by the second inscribed circle and the plane. Is formed.

More preferably, a wedge wire is used for the second rotating screen, and in a plane facing the axial direction of a wire constituting the wedge wire extending in the axial direction, the wedge wire extends in the rotational direction about the axis of the plane. The first inscribed circle defined by the seen front end is smaller than the second inscribed circle defined by the rear end, and a wedge shape is formed by the first inscribed circle and the plane. Have been.

[0029] More preferably, a wedge wire is used for the second rotating screen, and the wire constituting the wedge wire extending in the axial direction is rotated about the axis of the plane in the axial direction. The first inscribed circle defined by the front end as viewed in the direction is larger than the second inscribed circle defined by the rear end, and is wedge-shaped by the second inscribed circle and the plane. Are formed.

More preferably, a wedge wire is used for the first rotary screen, and a cross-sectional shape of a wire constituting the wedge wire surrounding the axis along a direction in which the axis extends around the axis. , A triangle whose base is directed toward the axis.

More preferably, a wedge wire is used for the second rotary screen, and a cross-sectional shape of a wire constituting the wedge wire surrounding the axis along a direction in which the axis extends around the axis is used. , A triangle whose base is directed toward the axis.

Next, the muddy water treatment method according to the present invention includes the following steps.

Using the first screen having a predetermined mesh size, the recovered muddy water is separated into coarse particles having a predetermined diameter and a particle diameter equal to or larger than the first particle diameter, and fine particles having a particle diameter smaller than the first particle diameter. It is separated into primary recovered mud containing particles.

Next, using a cyclone, the first recovered mud is used as a second recovered mud containing fine particles having a particle size equal to or larger than a second particle size smaller than the first particle size; It is separated into tertiary collected mud containing fine particles smaller than the second particle size.

Next, the second recovered mud is separated into a second recovered cake and water using a second screen having a mesh size smaller than the first screen.

Preferably, the second recovered cake is further dewatered using a sand screen.

[0037]

According to the muddy water treatment apparatus according to the present invention, the first rotating screen has the second rotating screen rotatable coaxially with the first rotating screen.

Thus, the muddy water can be processed while rotating the first and second screens in the same direction or different directions depending on the muddy water conditions, and thus the dewatering can be performed efficiently.

The second rotating screen is provided inside the first rotating screen, and the first rotating screen and the second rotating screen can be rotated about the same axis. Can be reduced in size.

Preferably, the second rotary screen is provided so that the opening in the outlet area is smaller than the opening in the inlet area. Further, the generatrix located at the lowermost end of the first rotating screen descends from the entrance area to the exit area. Further, the generatrix located at the lowermost end of the second rotating screen rises from the entrance area to the exit area. As a result, in the first rotating screen, the collected mud is processed while proceeding from the inlet area to the outlet area, and also in the second rotating screen, the collected mud gradually progresses from the inlet area to the outlet area. It can be dehydrated.

Preferably, a partition plate spirally extending from the entrance region to the exit region is provided on the inner surface of the second rotating screen, and further, the inner surface of the first rotating screen is also provided.
A partition plate spirally extends from the inlet area to the outlet area. This makes it possible for the collected mud in the first rotating screen and the second rotating screen to reliably proceed from the inlet area to the outlet area, and to reliably process the collected mud.

Preferably, a plurality of second rotating screens are arranged in the axial direction inside the first rotating screen. Thereby, it is possible to further improve the treatment capacity of the collected muddy water in the second screen.

Preferably, a wedge wire is used for the first and second rotating screens, and the wedge is formed by a first inscribed circle or a second inscribed circle and a plane facing the axial direction of a wire constituting the wedge wire. A shape is formed. Thus, the direction of the wedge and the rotation direction of the first and second rotating screens can be selected according to the muddy water conditions. As a result, the dewatering effect of the first rotating screen and the second rotating screen is maximized according to the muddy water conditions, and the muddy water treatment efficiency can be further improved.

Preferably, wedge wires are used for the first and second rotating screens, and the cross-sectional shape of the wire constituting the wedge wire surrounding the rotating shafts of the first and second rotating screens is set at the center. , And a triangle whose base is directed toward the axis. This makes it possible to further improve the efficiency of the muddy water treatment depending on the muddy water conditions.

Preferably, a sand screen is further provided in the outlet area of the second rotary screen,
It is possible to further improve the efficiency of the dehydration treatment.

[0046]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A muddy water treatment apparatus according to a first embodiment of the present invention will be described below with reference to the drawings. In addition,
The configuration of the muddy water treatment equipment using this muddy water treatment apparatus is the same as that described with reference to FIG. 16, and a description thereof will not be repeated.

First, the configuration of a muddy water treatment apparatus according to this embodiment will be described with reference to FIGS. 1 is an overall perspective view of the muddy water treatment apparatus in this embodiment, FIG. 2 is a longitudinal sectional view of the muddy water treatment apparatus shown in FIG. 1, and FIG. 3 is a cross-sectional view taken along line XX in FIG. FIG.

Referring to FIGS. 1 to 3, this muddy water treatment apparatus 50 has an inlet drum 60 and an outlet drum 58 in an inlet area and an outlet area, respectively. The inlet drum 60 and the outlet drum 58 are connected by a connecting beam 56 at four locations on the circumference at a 90 ° pitch so as to have the same rotation axis.

An outer rotating screen 52 is mounted in a substantially cylindrical shape so as to cover the inlet drum 60 and the outlet drum 58 and to be coaxial with the rotation axis of the inlet drum 60 and the outlet drum 58. This outer rotating screen 5
2 is appropriately fixed to the connecting beam 56 using a rib A72. The outer rotating screen 52 uses a wedge wire having a mesh size of about 1.0 to 10.0 mm.

Next, inside the outer rotating screen 52, truncated conical inner rotating screens 54A and 54B having an opening in the outlet area smaller than an opening in the inlet area are provided with the inlet and outlet drums 60 and 58. Two are continuously arranged in the axial direction so as to be coaxial. The inner rotating screens 54A and 54B are appropriately fixed to the connecting beam 56 using ribs B80.

The inner rotating screens 54A, 54A, 5A
For 4B, a wedge wire of about 0.2 to 2.0 mm is used so that the size of the mesh is smaller than the mesh of the outer rotating screen 52.

On the other hand, a guide roller 66 for supporting the inlet drum 60 and the outlet drum 58 is mounted at a predetermined position on a steel table 74 disposed so as to descend from the inlet area to the outlet area. ing. Inlet drum 6
0 and the exit drum 58 have guide rails 6 respectively.
4, 62 are provided, and the guide rails 64, 6 are provided.
The inlet drum 60 and the outlet drum 58 are rotatably supported while the guide roller 66 and the guide roller 66 are in contact with each other.

A driven gear 68 is connected to the entrance drum 60.
The driven gear 68 meshes with the driving gear of the driving device 70, so that the inlet drum 60 can be rotated.

A muddy water storage tank 76 is provided in a region below the outer rotating screen 52 of the steel table 74, and a residual soil tank 78 is provided below the outlet drum 58.

Next, referring to FIG. 4, the angle L ° between the lowermost generatrix of the outer rotating screen 52 and the horizontal plane, and the angle K ° between the lowermost generatrix of the inner rotating screen 54 and the horizontal plane. Will be described.

First, the outer rotating screen 52 aims at collecting relatively large gravels of 2000 μm or more from the collected muddy water. Therefore, the inclination of the steel table 74 is adjusted so that the lowermost generatrix of the outer rotating screen 52 descends from the entrance area to the exit area, and the angle L ° formed between the lowermost generatrix of the outer rotating screen 52 and the horizontal plane.
By setting such that 0 ° <L ≦ 10 °, the above object can be achieved.

Next, the inner rotating screen 54 has a size of 74 μm.
The purpose of the present invention is to sufficiently dehydrate water from collected mud having gravel of not less than m and less than 2000 μm. Therefore, by allowing the collected muddy water to pass through the inside rotating screen 54 over a relatively long time, the dewatering effect can be improved. Therefore, the inner rotating screen 54
Is desirably shaped so as to rise from the entrance area to the exit area, and the angle K ° between the lowermost generatrix of the inner rotating screen and the horizontal plane is 0 ° <K ≦ 10 °. By setting as described above, the above object can be achieved.

Since the rotation center axis 2 of the inner rotating screen 54 is inclined so as to descend from the inlet area to the outlet area, the collected mud inside the inner rotating screen 54 theoretically gradually decreases in the outlet area. However, in this case, it takes a considerable time for the collected muddy water to pass through the inner rotating screen 54, and thus the working efficiency is deteriorated. Therefore, in the present embodiment, partition plates 88A and 88B (see FIG. 2) spirally extending from the entrance area to the exit area are provided on the inner surface of the inner rotating screen 54. This partition plate 88A, 8
By rotating the inner rotating screen 54 according to 8B, the collected muddy water can be reliably advanced from the inlet area to the outlet area.

In the present embodiment, a portion having a predetermined width from the entrance side region of the outer rotating screen 52 forms the outer rotating screen 52 using a normal steel plate 86 without using a wedge wire. This is provided in order to prevent the wedge wire from being damaged due to the impact at the time when the collected muddy water inserted from the entrance side area is directly carried into the wedge wire.

In this embodiment, the above-mentioned effect can be obtained by using a normal wire mesh for the outer rotating screen 52 and the inner rotating screen 54. However, in order to further enhance the dewatering effect. , Wedge wire. Also, depending on the state of viscosity of mud,
It is necessary to appropriately select the direction of the wedge wire and the rotation direction of the outer rotating screen 52 and the inner rotating screen 54. Hereinafter, this point will be described.

First, the first direction of the wedge wire direction and the outer rotating screen 52 and the inner rotating screen 54
Will be described.

FIG. 5 shows, for example, the outer rotating screen 52.
6 is an enlarged view of a region surrounded by X in FIG.

Next, the improvement of the dewatering effect of the collected muddy water when a wedge wire is used will be described with reference to FIG.

The axially extending wire 52a constituting the wedge wire has a flat surface 52b extending toward the center of the rotating shaft. Inscribed circle C ₁ that is defined by the front end as viewed in the direction of rotation (arrow in the drawing Y direction) about the axis of the plane 52b is smaller than the inscribed circle C ₂ that is defined by the rear end, and, wedge-shaped C ₃ is formed by the inscribed circle C ₁ and the plane 52b. Thus, this portion the recovery mud wedge-shaped C ₃ collide, such as gravel contained in the recovered mud and (C) and water (B) is easily separated, it is possible to improve the dewatering effect. In this case, the lower the viscosity of the collected mud, the more effective.

Next, a second relationship between the direction of the wedge wire and the rotation direction of the outer rotating screen 52 and the inner rotating screen 54 will be described.

FIG. 7 shows, for example, the outer rotating screen 52.
8 shows a state of muddy water in the outer rotating screen, and FIG. 8 is an enlarged view of a region surrounded by X in FIG. FIG. 9 is a schematic diagram illustrating a state of the muddy water dewatering process in the outer rotating screen 52.

The axially extending wire 52a constituting the wedge wire in the second relationship has a flat surface 52b extending toward the center of the rotating shaft. Inscribed circle C ₁ that is defined by the front end as viewed in the direction of rotation (arrow in the drawing Y direction) about the axis of the plane 52b is larger than the inscribed circle C ₂ that is defined by the rear end, and, inscribed circle C ₂ and wedge C ₃ by the plane 52B is formed. Thereby, when the viscosity of the collected muddy water is higher than that of the first relation, as shown in FIG. The water (B) contained in the muddy water is made to easily flow out on the right side in the drawing below the outer rotating screen 52. Thereby, even when the viscosity of the collected muddy water is relatively high, the dewatering effect can be improved. The second relationship can also be realized by reversing the rotation direction Y of the first relationship in FIG.

In the first and second relations described above, the relation between the axially extending wires 52a constituting the wedge wires of the outer rotating screen 52 and the inner rotating screen 54 is described, but the present invention is not limited to this. By providing the wire surrounding the shaft around the shaft constituting the wedge wire as shown in FIG. 10, the dewatering efficiency of the collected muddy water can be further improved.

In FIG. 10, the cross-sectional shape of the wire 160a constituting the wedge wire along the direction in which the shaft 160 extends has a substantially triangular shape with the base 160b directed toward the shaft 160. The angle α formed between the bottom 160b and the plane P orthogonal to the rotation axis 160 is changed according to the viscosity of the collected mud, so that the most efficient collected mud that matches the viscosity of the collected mud is obtained. Dehydration can be performed.

Next, a dehydrating method using the above-described dehydrating apparatus will be described with reference to FIGS.
FIG. 11 is a flowchart illustrating this dehydration treatment method.

First, the collected muddy water (A) collected from the excavator is carried into the outer rotating screen 52,
Next, it is separated into recovered muddy water (B) and coarse particles (C) having a particle size of 2000 μm or more. The first collection mud (B) is stored in a storage tank 76, and the coarse particles (C) are collected in a residual soil tank 78.

Next, the primary recovered mud (B) stored in the storage tank 76 is transported to the cyclone 82 by the pump 84. The first collected mud (B) conveyed to the cyclone 82 includes a second collected mud (G) containing fine particles of 74 μm or more and less than 2000 μm, and a third collected mud (D) containing fine particles of 74 μm or less. And separated.

The tertiary collected mud (D) is then supplied to the regulating tank and stored. On the other hand, the second collection mud (G)
Since it contains a considerable amount of water and cannot be discarded as it is as it is, it is necessary to dehydrate the water. Then, the secondary collected muddy water (G) is carried into the inner rotating screen 54. Inner rotating screen 54
The second collection mud (G) carried into the inside is 20-30w
Water is dehydrated to about t%. The dewatered second recovered cake (F) is discarded in the residual soil tank 78, and the dewatered water (E) is recovered again in the storage tank 76, and the cyclone 82 together with the first recovered muddy water (B). Transported to

As described above, the tertiary collected mud containing fine particles of 74 μm or less can be collected from the collected mud (A) discharged from the excavator.

As described above, according to the first embodiment, the inner rotating screen that is rotatable in synchronization with the outer rotating screen is provided inside the outer rotating screen. Thereby, the processing of the collected mud can be performed while rotating the outer and inner rotating screens, so that the collected mud can be processed very quietly without generating noise or vibration. Further, since the inner rotating screen is provided inside the outer rotating screen, and the outer rotating screen and the inner rotating screen have the same rotation axis, it is possible to use the same driving device, and the muddy water treatment can be performed. It is possible to reduce the size of the device.

In the above embodiment, two inner rotating drums are provided in the axial direction. However, depending on the content of gravel and the like contained in the collected mud, as shown in FIG. It may be 1. Also in the axial direction 2
The same operation and effect can be obtained by providing two or more inner rotating drums.

Further, in the above embodiment, the outer rotating drum is cylindrical in shape, and the steel table is provided with a predetermined inclination. However, the present invention is not limited to this structure. For example, a horizontal plane shown in FIG. The steel pedestal should be horizontal and frusto-conical in shape with the opening in the exit area larger than the opening in the entrance area of the outer rotating screen, so that the relationship with the busbar at the bottom of the screen can be maintained. The same operation and effect can be obtained.

Further, in the above embodiment, the partition plate spirally extending from the entrance region to the exit region is provided only on the inner surface of the inner rotating screen, but also extends from the entrance region to the exit region on the inner surface of the outer rotating screen. The same operation and effect can be obtained by providing a spiral partition plate.

Next, a muddy water treatment apparatus according to a second embodiment of the present invention will be described with reference to FIGS.

The structure of the dehydration processing apparatus in this embodiment is different from that of the dehydration processing apparatus shown in FIG. 1 described in the first embodiment, as shown in FIG. A sand screen 100 is further provided in the exit area to further increase the dewatering efficiency.

FIG. 14 is a longitudinal sectional view of the muddy water treatment apparatus shown in FIG. 13, and FIG. 15 is a view taken along the line YY in FIG.

Referring to FIGS. 14 and 15, first, this sand screen 100 includes a frame 101 fixed to a steel base 74 and a brace 103 for suspending a main body 102 of the sand screen from this frame 101.
And

Referring to FIGS. 14 and 15, secondary cake (F) discharged from inner rotating screen 54A
Is further collected on the main body 103 of the sand screen 100, and is further separated into moisture (I) and residual soil (H) by the vibration in the main body 103. And the remaining soil (H) is discarded in the remaining soil tank 78.

As described above, according to the dehydrating apparatus of the second embodiment, the secondary recovered cake discharged from the inner rotating screen is further subjected to the use of a sand screen as compared with the dehydrating apparatus of the first embodiment. By performing dehydration, the dehydration efficiency can be further increased.

Next, a dehydrating apparatus according to a third embodiment of the present invention will be described with reference to FIG. FIG. 16 is a view corresponding to the cross-sectional view of FIG.

The structure of the dehydrating apparatus in this embodiment is different from that of the first embodiment shown in FIG. 2 in that the outer rotating screen 52 and the inner rotating screen 52 are different according to the structure of the second embodiment. In contrast to the structure in which the rotating screens 54A and 54B rotate in synchronization with each other, in the dehydration processing apparatus of this embodiment, the outer rotating screen 52 and the inner rotating screens 54A and 54B rotate independently. It has a structure that can be.

First, the outer rotating screen 52 supports the steel plate 56 provided in the entrance area and the exit area by the roller guide 178 provided in the steel base 74, and further, the sprocket 175 is provided in the entrance area of the outer rotating screen 52. Is provided, and is rotatable by a driving device 70 via a roller chain 176.

On the other hand, the inner rotating screens 54A, 54B
Is rotatable about a rotation shaft 171.
The rotating shaft 171 is supported by a bearing 172 provided on the steel base 74 in the inlet region and the outlet region, and is connected to a sprocket 174 provided on the rotating shaft 171 by the driving device 1.
70 is transmitted through the roller chain 173.

In the third embodiment having the above-described structure, the outer rotating screen 52 and the inner rotating screens 54A and 54B are rotated in the same rotational direction as in the above-described embodiment.
In addition to the same rotation speed, it is possible to realize the same rotation direction / left rotation, reverse rotation direction / same rotation speed, reverse rotation direction / left rotation, maximizing the dehydration rate of muddy water that differs depending on the use site As can be achieved,
The muddy water treatment device can be adjusted. Also in this embodiment, a sand screen may be provided as shown in FIG. 14 to further enhance the dewatering effect of the muddy water.

It should be understood that the above-described embodiment is illustrative in all aspects and is not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0091]

According to the muddy water treatment apparatus according to the present invention, the first rotating screen has the second rotating screen rotatable about the same axis as the first rotating screen. Thereby, since the muddy water can be processed while rotating the first rotating screen and the second rotating screen in the same direction or different directions depending on the muddy water conditions, dehydration can be performed efficiently.

The second rotating screen is provided inside the first rotating screen, and the first rotating screen and the second rotating screen can be rotated about the same axis. Can be achieved.

[0093] Preferably, the second rotating screen has a shape in which the opening in the outlet area is smaller than the opening in the inlet area. More preferably, the generatrix located at the lowermost end of the first rotating screen descends from the entrance area to the exit area. Further, the generatrix located at the lowermost end of the second rotating screen rises from the entrance area to the exit area. As a result, the collected muddy water is processed while proceeding from the inlet area to the outlet area in the first rotary screen, and the collected muddy water is also gradually processed from the inlet area to the outlet area in the second rotary screen. Becomes possible.

Preferably, the inner surface of the second rotating screen has a partition plate extending spirally from the inlet region to the outlet region. More preferably, the inner surface of the first rotating screen has the partition surface extending from the inlet region to the outlet region. And a partition plate extending spirally. This makes it possible for the collected muddy water to reliably advance from the inlet area to the outlet area in the first rotary screen and the second rotary screen, thereby improving the processing capacity of the collected muddy water.

Preferably, a plurality of second rotating screens are arranged in the axial direction inside the first rotating screen. Thereby, it is possible to further improve the processing capability of the second rotating screen for the collected muddy water.

Preferably, a wedge wire is used for the first rotating screen, and a wedge shape is formed by a first inscribed circle defined by a front end viewed in the rotation direction and a plane in a plane facing the axial direction of the wedge wire. Is formed.

[0097] More preferably, a wedge wire is used for the second rotating screen, and a wedge shape is formed between a plane in the axial direction of the wedge wire and the first or second inscribed circle. I have. Thereby, the direction of the wedge and the rotation direction of the first and second rotating screens can be appropriately selected depending on the muddy water conditions, and the optimum conditions can be set so that the water contained in the collected muddy water can easily pass through the wire mesh. As a result, the dewatering effect of the collected mud increases, and the first and second
It is possible to further improve the processing capability of the rotating screen for the collected muddy water.

Preferably, by providing a sand screen in the exit area of the second rotating screen, the efficiency of the dewatering process can be further improved.

Preferably, a wedge wire is used for the first rotating screen and the second rotating screen,
With the rotation axis of the rotating screen and the second rotating screen as the center, the cross-sectional shape of the wire constituting the wedge wire surrounding the axis along the direction in which the axis extends is a triangle with the base directed toward the axis. Is provided. Thereby, the dewatering efficiency of the collected muddy water is further improved, and it is possible to further improve the treatment capacity of the first and second rotating screens for the collected muddy water.

Next, according to the muddy water treatment method based on the present invention, the collected muddy water is separated into fine particles and the primary collected muddy water using the first rotating screen, and the primary collected muddy water is separated using the cyclone. The muddy water is separated into a second collected muddy water and a third collected muddy water, and a second rotating screen is used to dewater the second collected muddy water. This makes it possible to obtain the tertiary collected mud containing fine particles having a particle diameter smaller than the second particle size from the collected mud, and to simultaneously perform the dehydration of the second collected mud. As a result, it becomes possible to improve the efficiency of the treatment of the collected muddy water.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a muddy water treatment apparatus according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the muddy water treatment apparatus in the first embodiment based on the present invention.

FIG. 3 is a cross-sectional view of the muddy water treatment apparatus in the first embodiment based on the present invention.

FIG. 4 is a diagram showing a relationship between a bus located at the bottom of the outer rotating screen, a bus located at the bottom of the inner rotating screen, and a horizontal plane.

FIG. 5 is a first cross-sectional view of the outer rotating screen.

FIG. 6 is a partially enlarged sectional view of a region surrounded by X in FIG. 5;

FIG. 7 is a second cross-sectional view of the outer rotating screen.

FIG. 8 is a partially enlarged sectional view of a region surrounded by X in FIG. 7;

FIG. 9 is a schematic view showing a state of muddy water in the outer rotating screen.

FIG. 10 is a cross-sectional view along the direction in which the rotation axis of the outer rotating screen extends.

FIG. 11 is a flowchart of a muddy water treatment method in the first embodiment based on the present invention.

FIG. 12 is a longitudinal sectional view showing another structure of the muddy water treatment apparatus in the first embodiment based on the present invention.

FIG. 13 is an overall perspective view of a muddy water treatment apparatus according to a second embodiment based on the present invention.

FIG. 14 is a longitudinal sectional view of a muddy water treatment apparatus according to a second embodiment of the present invention.

15 is a view taken in the direction of arrows YY in FIG. 14;

FIG. 16 is a longitudinal sectional view of a muddy water treatment apparatus according to a third embodiment of the present invention.

FIG. 17 is a composition diagram for explaining a muddy water treatment method using a conventional muddy water treatment facility.

FIG. 18 is a composition diagram for explaining components of the collected muddy water.

[Explanation of symbols]

 Reference Signs List 50 muddy water treatment device 52 outer rotating screen 54A, 54B inner rotating screen 56 connecting beam 58 outlet drum 60 inlet drum 62, 64 guide rail 66 guide roller 68 non-moving gear 70 driving device 74 steel table 76 storage tank 78 remaining soil tank 82 cyclone 84 Pump 86 Steel plate 88A, 88B Partition plate In the drawings, the same reference numerals indicate the same or corresponding parts.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B01D 33/06-33/13 C02F 11/12 E21B 21/06 E21D 9/06

Claims (14)

(57) [Claims] 1. A muddy water treatment apparatus used in a muddy water method in which excavation is performed by using an excavator using muddy water, and has openings at both ends so that one end side forms an inlet area and the other end side forms an outlet area. A first rotating screen that is rotatable about an axis and is made of a wire mesh having a predetermined mesh size, and a first rotating screen inside the first rotating screen that is rotatable about the axis. , A substantially cylindrical second rotating screen made of a wire mesh having a mesh size smaller than a mesh size of the wire mesh of the first rotating screen, the second rotating screen having openings in the inlet area and the outlet area. The muddy water treatment device, comprising: the second rotating screen, wherein an opening in the outlet area is smaller than an opening in the inlet area. 2. The muddy water treatment apparatus according to claim 1, wherein a generatrix located at a lowermost end of the first rotating screen descends from the entrance area to the exit area. 3. The muddy water treatment apparatus according to claim 2, wherein a generatrix located at a lowermost end of the second rotating screen rises from the entrance area to the exit area. 4. The muddy water treatment apparatus according to claim 1, wherein a plurality of the second rotating screens are arranged inside the first rotating screen in the axial direction. 5. The muddy water treatment apparatus according to claim 3, wherein a partition plate spirally extending from the entrance area to the exit area is provided on an inner surface of the second rotating screen. 6. The muddy water treatment apparatus according to claim 2, further comprising a partition plate spirally extending from the entrance area to the exit area on an inner surface of the first rotating screen. 7. A wedge wire is used for the first rotating screen, and in a plane facing the axial direction of a wire constituting the wedge wire extending in the axial direction, the wedge wire is viewed in a rotational direction about the axis of the plane. A first inscribed circle defined by the front end is smaller than a second inscribed circle defined by the rear end, and a wedge shape is formed by the first inscribed circle and the plane. The muddy water treatment device according to claim 1. 8. A wedge wire is used for the first rotating screen, and in a plane facing the axial direction of a wire constituting the wedge wire extending in the axial direction, the wedge wire is viewed in a rotational direction about the axis of the plane. A first inscribed circle defined by the front end is larger than a second inscribed circle defined by the rear end, and a wedge shape is formed by the second inscribed circle and the plane. The muddy water treatment device according to claim 1. 9. A wedge wire is used for the second rotating screen, and in a plane facing the axial direction of a wire constituting the wedge wire extending in the axial direction, the wedge wire is viewed in a rotational direction about the axis of the plane. A first inscribed circle defined by the front end is smaller than a second inscribed circle defined by the rear end, and a wedge shape is formed by the first inscribed circle and the plane. The muddy water treatment device according to claim 1. 10. A wedge wire is used for the second rotating screen, and in a plane facing the axial direction of a wire constituting the wedge wire extending in the axial direction, the wedge wire is viewed in a rotational direction about the axis of the plane. A first inscribed circle defined by the front end is larger than a second inscribed circle defined by the rear end, and a wedge shape is formed by the second inscribed circle and the plane. The muddy water treatment device according to claim 1. 11. A wire constituting the wedge wire surrounding the axis around the axis, using a wedge wire for the first rotating screen, and a cross section of the wire along a direction in which the axis extends. The muddy water treatment device according to claim 1, wherein the shape is a triangle with a base directed toward the axis. 12. A wire constituting the wedge wire surrounding the axis about the axis, using a wedge wire for the second rotating screen, and a cross-sectional shape of the wire along a direction in which the axis extends. The muddy water treatment apparatus according to claim 1, wherein a triangle is a triangle having a base directed toward the axis. 13. The muddy water treatment apparatus according to claim 1, wherein a sand screen is provided in an outlet area of the second rotary screen. 14. A muddy water treatment method for reusing collected muddy water discharged from an excavator used in a muddy water method, wherein the collected muddy water is used by a first screen having a predetermined mesh size. A first coarse particle having a predetermined diameter and having a particle diameter equal to or greater than a first particle diameter;
Separating the first collected muddy water from the second collected muddy water, using a wet cyclone, including a fine particle having a second particle diameter smaller than the first particle diameter and a second particle diameter or more. Separating the second collected muddy water and the third collected muddy water containing fine particles having a particle diameter smaller than the second particle size, and the second collected muddy water having a mesh size smaller than the first screen. Using two screens, the second
A muddy water treatment method comprising: a step of separating the second recovered cake and water; and a step of further dehydrating the second recovered cake using a sand screen.