JPH0866700A - Mud water treating device and mud water treatment using the same - Google Patents

Abstract

PURPOSE: To make vibration and noise low and the size of a device small. CONSTITUTION: This device has an inner rotary screen 54 rotatable in synchronization with an outer rotary screen 52 within the outer rotary screen 52. The inner rotary screen 54 rotates around the same axis as that of the outer rotary screen 52 as a center. As a result, the vibration and noise are lessened and the size of the device is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a muddy water separation device, and more particularly to a muddy water separation device used in a muddy water construction method in which muddy water is used for excavation by an excavator.

[0002]

2. Description of the Related Art Conventionally, in a muddy water construction method in which muddy water is used to excavate by an excavator, muddy water treatment equipment for recovering excavated soil from the muddy water discharged from the excavator and reusing the recovered muddy water. It has been known. FIG. 17 is a schematic diagram showing a configuration of a conventional muddy water treatment facility. With reference to FIG. 17, the conventional muddy water treatment facility has an excavator 10 for excavating.
A muddy water treatment device 10 for receiving the collected muddy water collected from No. 1 and collecting 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 treated by the muddy water treatment device 10. Stored in the adjustment tank 105 for supplying the recovered mud water after the specific gravity adjustment to the excavator 101 again and discharging the recovered mud water that is not reused, and 74 stored in the adjusting tank 105.
Fresh water is supplied to the recovered muddy water containing silt and clay of less than μm to adjust the specific gravity thereof, and recovered muddy water containing silt and clay of less than 74 μm discharged from the adjusting tank 105 that is not reused. Waste mud tank 107 for storing, and 74μ stored in the waste mud tank 107
A separation device 300 for separating recovered muddy water containing silt and clay of m or less into solid and liquid, and a PH neutralization device 40 for neutralizing the PH of the water separated by the separation device 300 are provided. .

The muddy water treatment device 10 includes a cyclone 13 for classifying recovered muddy water recovered from the excavator 101 into gravel or the like having a particle size of 74 μm or more, silt having a particle size of 74 μm or less, and excavation. First, gravel or the like having a large particle size of 200 μm or more is recovered from the recovered muddy water from the machine 101, and the remaining recovered muddy water is discharged and gravel having a particle size of 74 μm or more classified by the cyclone 13 is discharged. The screen 11 for classifying gravel and the like from the recovered mud containing water, and the screen 11
The collected mud water discharged when collecting gravel and the like having a particle size of 000 μm or more is stored, and the stored 2000
A lower tank 12 for supplying recovered muddy water containing gravel or the like having a particle size of μm or less to the cyclone 13, and gravel or sand of 74 μm or more collected by the screen 11 are provided on the carrier 104. And a conveyor 102 for transporting the hopper 103.

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

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

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

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

Among the recovered mud water having such a composition,
In the conventional muddy water treatment equipment, fine sand, gravel, etc. having a particle size of 74 μm or less are collected by the muddy water treatment device 10 to obtain 74 μm.
A two-step recovery method of recovering silt, clay or the like having a size of m or less by the separating device 300 is adopted.

Next, referring again to FIG. 17, a mud water treatment operation by the conventional mud water treatment equipment will be described. First,
The recovered muddy water collected from the excavator 101 is supplied to the screen 11 of the muddy water treatment device 10. The screen 11 first collects gravel or the like having a size of 2000 μm or more using vibration, and the remaining collected mud is discharged to the lower tank 12. The recovered muddy water containing gravel or the like having a particle size of 2000 μm or less is collected in the cyclone 13 by the lower tank 12.
Is supplied to. The cyclone 13 performs classification with a particle size of 74 μm, and the recovered muddy water containing gravel and the like having a particle size of 74 μm or more is supplied to the screen 11 again. As a result, the screen 11 collects gravel or the like having a particle size of 74 μm or more.

The collected gravel or the like is conveyed to the hopper 103 by the conveyor 102, and is further loaded on the transportation vehicle 104 arranged below the hopper 103.

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

Here, 74 which has passed through the muddy water treatment device 10
The specific gravity of the recovered mud water containing silt or the like having a particle size of less than or equal to μm is about 1.25. To make this specific gravity 1.1, a large amount of fresh water is supplied from the fresh water tank 106 and from the adjusting tank 105. A large amount of collected mud is discharged.

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

[0014]

However, the muddy water treatment device used in the above muddy water treatment equipment has the following problems.

The screen used in this muddy water treatment device must be vibrated at a high speed in order to separate gravel of 2000 μm or more from the recovered muddy water. For this reason, noise is generated and the ground vibrates violently. Therefore, it is necessary to provide a vibration isolator and a soundproof device. In particular, in urban areas, even if these soundproofing and vibrationproofing measures are taken, it is gradually becoming impossible to use due to complaints from local residents.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a muddy water treatment device which has a low vibration and a low noise and which is downsized.

[0017]

In the muddy water treatment device according to the present invention, one end side has an inlet region and the other end side has an outlet region so as to have an opening at both ends and to be rotatable about an axis. A substantially cylindrical first rotating screen made of a wire mesh having a predetermined mesh size;
Inside the rotary screen, the mesh is arranged so as to be rotatable about the axis, has openings in the inlet region and the outlet region, and has a mesh smaller than the mesh size of the wire mesh of the first rotary screen. And a substantially cylindrical second rotating screen made of wire mesh having a size.

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

More preferably, the first rotary screen and the second rotary screen can rotate in different directions.

More preferably, the second rotary screen is provided so that the opening in the outlet region is smaller than the opening in the inlet region.

More preferably, the bus bar located at the lowermost end of the first rotating screen descends from the inlet region to the outlet region.

More preferably, the bus bar located at the lowermost end of the second rotary screen rises from the inlet region to the outlet region.

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

More preferably, the inner surface of the second rotating screen has a partition plate spirally extending from the inlet region to the outlet region.

More preferably, the inner surface of the first rotating screen has a partition plate spirally extending from the inlet region to the outlet region.

More preferably, a wedge wire is used for the first rotating screen, and a wire rod forming the wedge wire extending in the axial direction has a plane in the axial direction that is directed about the axis of the plane. The first inscribed circle defined by the front end 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. Has been formed.

More preferably, a wedge wire is used for the first rotary screen, and a wire rod forming the wedge wire extending in the axial direction is rotated in a rotation direction about the axis of the flat surface in a plane facing the axial direction. The first inscribed circle defined by the front end 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. Has been formed.

More preferably, a wedge wire is used for the second rotary screen, and a wire rod forming the wedge wire extending in the axial direction is provided with a plane extending in the axial direction in the rotation direction about the axis of the plane. The first inscribed circle defined by the front end as viewed is smaller than the second inscribed circle defined by the rear end, and the first inscribed circle and the plane form a wedge shape. Has been done.

Further preferably, a wedge wire is used for the second rotary screen, and a wire rod forming the wedge wire extending in the axial direction is rotated about the axis of the plane in a plane facing the axial direction. The first inscribed circle defined by the front end as seen in the direction is larger than the second inscribed circle defined by the rear end, and the second inscribed circle and the plane form a wedge shape. Are formed.

Further, more preferably, a wedge wire is used for the first rotating screen, and a cross-sectional shape of a wire which constitutes the wedge wire surrounding the shaft is centered on the shaft and along a direction in which the shaft extends. , A triangle whose base is oriented toward the axis.

Further preferably, a wedge wire is used for the second rotary screen, and a cross-sectional shape of a wire which constitutes the wedge wire surrounding the shaft is centered on the shaft and along a direction in which the shaft extends. , A triangle whose base is oriented 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 subjected to coarse particles having a predetermined diameter and a particle diameter equal to or larger than the first particle diameter, and fine particles having a diameter smaller than the first particle diameter. Separation into primary recovery mud containing particles.

Next, the above-mentioned first recovered mud water is subjected to a second recovery mud water containing fine particles having a particle diameter not less than the second particle diameter smaller than the first particle diameter by using a cyclone, Separation into a third recovered mud containing fine particles of less than the second particle size.

Next, the secondary recovered muddy water is separated into a secondary recovered cake and water by using a second screen having a mesh size smaller than that of the first screen.

Preferably, the secondary recovered cake is further dehydrated using a sand screen.

[0037]

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

As a result, the muddy water can be treated while rotating the first and second screens in the same direction or in different directions depending on the condition of the muddy water, so that the dewatering can be efficiently performed.

Further, since the second rotary screen is provided inside the first rotary screen, and the first rotary screen and the second rotary screen can rotate about the same axis, the muddy water treatment device It is possible to reduce the size.

Further, preferably, the second rotary screen is provided so that the opening in the outlet region is smaller than the opening in the inlet region. Furthermore, the bus bar located at the lowermost end of the first rotating screen descends from the inlet region to the outlet region. Furthermore, the bus bar located at the lowermost end of the second rotating screen rises from the inlet region to the outlet region. As a result, in the first rotating screen, the recovered muddy water is processed while advancing from the inlet region to the outlet region, and also in the second rotating screen, the recovered muddy water gradually advances from the inlet region to the outlet region. It is possible to be dehydrated.

Preferably, the inner surface of the second rotating screen has a partition plate spirally extending from the inlet region to the outlet region, and further, the inner surface of the first rotating screen also has a partition plate.
It has a partition plate spirally extending from the inlet region to the outlet region. As a result, the recovered muddy water in the first rotary screen and the second rotary screen can surely proceed from the inlet region to the outlet region, and the recovered muddy water can be reliably treated.

Preferably, a plurality of second rotary screens are axially arranged inside the first rotary screen. This makes it possible to further improve the treatment capacity of the recovered mud water in the second screen.

Preferably, wedge wires are used for the first and second rotating screens, and the wedge wire is formed by the first inscribed circle or the second inscribed circle and a plane of the wire constituting the wedge wire which faces in the axial direction. The shape is formed. Thereby, the direction of the wedge and the rotation directions of the first and second rotary screens can be selected depending on the condition of the muddy water. As a result, it is possible to maximize the dewatering effect of the first rotary screen and the second rotary screen in accordance with the condition of muddy water, and further improve the efficiency of muddy water treatment.

Further, preferably, a wedge wire is used for the first and second rotary screens, and the cross-sectional shape of the wire material forming the wedge wire surrounding the rotary shafts of the first and second rotary screens is centered. , A triangle with the bottom side facing the side of the axis. This makes it possible to further improve the efficiency of muddy water treatment depending on the condition of muddy water.

Further preferably, by further providing a sand screen in the exit 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 device according to a first embodiment of the present invention will be described below with reference to the drawings. In addition,
The structure of the muddy water treatment equipment using this muddy water treatment device is the same as that described with reference to FIG.

First, the construction of the 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 vertical sectional view of the muddy water treatment apparatus shown in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line XX in FIG. The figure is shown.

With reference to FIGS. 1 to 3, the muddy water treatment device 50 has an inlet drum 60 and an outlet drum 58 in the inlet region and the outlet region, respectively. The inlet drum 60 and the outlet drum 58 are connected at four positions on the circumference at a pitch of 90 ° by connecting beams 56 so that they have the same rotation axis.

An outer rotary 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 rotational axes of the inlet drum 60 and the outlet drum 58. This outside rotating screen 5
2 is appropriately fixed to the connecting beam 56 by using a rib A72. The outer rotary screen 52 uses a wedge wire having a mesh size of about 1.0 to 10.0 mm.

Next, inside the outer rotary screen 52, there are conical trapezoidal inner rotary screens 54A, 54B having inlet and outlet drums 60, 58 in which the opening in the outlet area is smaller than the opening in the inlet area. Two of them are continuously arranged in the axial direction so as to be coaxial. The inner rotary screens 54A and 54B are appropriately fixed to the connecting beam 56 by using ribs B80.

Further, the inner rotary screens 54A, 5
For 4B, a wedge wire having a size of about 0.2 to 2.0 mm is used so that the size of the mesh is smaller than that 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 attached to a predetermined position of the steel stand 74 arranged so as to descend from the inlet region to the outlet region. ing. Entrance 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 contact each other.

Further, the driven drum 68 is provided on the inlet drum 60.
Is formed, and the driven gear 68 meshes with the drive gear of the drive device 70, whereby the inlet drum 60 can rotate.

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

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

First, the outer rotary screen 52 is intended to collect relatively large gravel of 2000 μm or more from the recovered muddy water. Therefore, the inclination of the steel stand 74 is adjusted so that the lowermost busbar of the outer rotating screen 52 descends from the inlet region to the outlet region, and the angle L ° formed between the lowermost busbar of the outer rotating screen 52 and the horizontal plane.
However, the above object can be achieved by setting such that 0 ° <L ≦ 10 °.

Next, the inner rotating screen 54 is
The purpose is to sufficiently dehydrate the recovered mud water containing gravel or the like having a size of m or more and less than 2000 μm. Therefore, by allowing the collected mud to pass through the inner rotary screen 54 over a relatively long time, the dewatering effect can be enhanced. Therefore, the inner rotating screen 54
It is desirable that the lowermost generatrix of the inner rotary screen rises from the inlet region to the outlet region, and the angle K ° between the lowermost generatrix of the inner rotary screen and the horizontal plane is 0 ° <K ≦ 10 °. By setting as above, the above-mentioned object can be achieved.

Since the central axis of rotation 2 of the inner rotary screen 54 is inclined so as to descend from the inlet region to the outlet region, the recovered mud inside the inner rotary screen 54 theoretically gradually exits. However, in this case, it takes a considerable amount of time for the collected mud to pass through the inside of the inner rotary screen 54, which deteriorates the work efficiency. Therefore, in this embodiment, partition plates 88A and 88B (see FIG. 2) spirally extending from the inlet region to the outlet region are provided on the inner surface of the inner rotary screen 54. This partition plate 88A, 8
By 8B, by rotating the inner rotary screen 54, it becomes possible to reliably advance the recovered mud water from the inlet region toward the outlet region.

In this embodiment, the outer rotary screen 52 is formed by using a normal steel plate 86 in a portion of a predetermined width from the inlet side area of the outer rotary screen 52 without using a wedge wire. This is provided in order to prevent damage to the wedge wire due to the impact at the time when the recovered muddy water inserted from the inlet side area is directly carried into the wedge wire.

Further, in the present embodiment, the above-mentioned effects can be obtained by using ordinary wire mesh for the outer rotary screen 52 and the inner rotary screen 54, but for the purpose of further enhancing the dehydration effect. , Using a wedge wire. Also, depending on the viscosity of the muddy water,
It is necessary to appropriately select the direction of the wedge wire and the rotation directions of the outer rotary screen 52 and the inner rotary screen 54. Hereinafter, this point will be described.

First, the direction of the wedge wire and the first of the outer rotary screen 52 and the inner rotary screen 54
The relationship will be described.

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

Next, the improvement of the dehydration effect of the recovered mud water when the wedge wire is used will be described with reference to FIG.

The axially extending wire rod 52a forming the wedge wire has a flat surface 52b directed toward the center of the rotary shaft. The inscribed circle C ₁ defined by the front end as viewed in the rotation direction (the direction of the arrow Y in the drawing) about the axis of the plane 52b is smaller than the inscribed circle C ₂ defined by the rear end, and A wedge shape C ₃ is formed by the inscribed circle C ₁ and the flat surface 52b. Thereby, the recovered mud collides with the wedge-shaped portion C ₃ , and the gravel and the like (C) and the water (B) contained in the recovered mud are easily separated, and the dehydration effect can be improved. In this case, it is effective that the viscosity of the recovered mud water is low.

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

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

The axially extending wire rod 52a forming the wedge wire in the second relationship has a flat surface 52b directed toward the center of the rotary shaft. The inscribed circle C ₁ defined by the front end viewed in the rotation direction (direction of arrow Y in the drawing) about the axis of the plane 52b is larger than the inscribed circle C ₂ defined by the rear end, and A wedge shape C ₃ is formed by the inscribed circle C ₂ and the flat surface 52B. As a result, when the viscosity of the recovered mud is higher than that in the first relationship, the recovered mud flows relatively upward in the rotation direction of the outer rotary screen 52 as shown in FIG. The water (B) contained in the muddy water is made to easily flow out on the right side in the figure below the outer rotary screen 52. This makes it possible to improve the dewatering effect even when the viscosity of the recovered mud water is relatively high. The second relationship can also be realized by reversing the rotation direction Y of the first relationship in FIG.

In the first and second relationships described above, the relationship between the axially extending wire rods 52a forming the wedge wires of the outer rotary screen 52 and the inner rotary screen 54 is described, but the present invention is not limited to this. By providing a wire rod surrounding the shaft, which constitutes the wedge wire, as shown in FIG. 10, the dehydration efficiency of the recovered mud water can be further improved.

In FIG. 10, the wire rod 160a forming the wedge wire has a substantially triangular cross-sectional shape along the direction in which the shaft 160 extends, with the bottom side 160b facing the shaft 160 side. Further, the angle α formed by the base 160b and the plane P orthogonal to the rotation axis 160 is changed according to the viscosity of the recovered mud so that the most efficient recovered mud that matches the viscosity of the recovered mud. It becomes possible to perform dehydration.

Next, with reference to FIGS. 2 and 11, a dehydration treatment method using the dehydration treatment apparatus will be described.
Note that FIG. 11 is a flowchart showing this dehydration treatment method.

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

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

The third recovered mud water (D) is then supplied to and stored in the adjusting tank. On the other hand, the second recovered mud (G) is
Since it contains a considerable amount of water, it cannot be discarded as residual soil as it is, so it is necessary to dehydrate the water. Therefore, the secondary recovered muddy water (G) is carried into the inner rotary screen 54. Inner rotating screen 54
The second recovered muddy water (G) carried in was 20 to 30w
Water is dehydrated to about t%. The dehydrated secondary recovery cake (F) is abandoned in the residual soil tank 78, the dehydrated moisture (E) is recovered again in the storage tank 76, and the cyclone 82 together with the primary recovered mud water (B). Be transported to.

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

As described above, according to the first embodiment, the inner rotary screen rotatable in synchronization with the outer rotary screen is provided inside the outer rotary screen. Accordingly, the recovered muddy water can be processed while rotating the outer and inner rotary screens, so that the recovered muddy water can be processed extremely quietly without generating noise or vibration. Further, since the inner rotary screen is provided inside the outer rotary screen and the outer rotary screen and the inner rotary screen have the same rotation axis, it is possible to use the same drive device, and the muddy water treatment is possible. 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 or the like contained in the recovered muddy water, the inner rotating drum may be formed as shown in FIG. It may be 1. 2 in the axial direction
Even if two or more inner rotary drums are provided, the same effect can be obtained.

Further, in the above embodiment, the outer rotary drum has a cylindrical shape and the steel stand is provided with a predetermined inclination. However, the invention is not limited to this structure, and for example, the horizontal plane and the outer rotary drum shown in FIG. In order to maintain the relationship with the bus bar at the bottom of the screen, the steel stand should be horizontal and the frustoconical shape should have a larger opening in the exit area than in the entrance area of the outer rotating screen. The same action and effect can be obtained as well.

Further, in the above embodiment, the partition plate spirally extending from the inlet region to the outlet region is provided only on the inner surface of the inner rotating screen, but the inner surface of the outer rotating screen also extends from the inlet region to the outlet region. Even if a spiral partition plate is provided, the same effect can be obtained.

Next, a muddy water treatment device according to a second embodiment of the present invention will be described with reference to FIGS. 13 and 14.

The structure of the dehydration treatment apparatus in this embodiment is, as compared with the dehydration treatment apparatus shown in FIG. 1 described in the first embodiment, as shown in FIG. 13, the outlet drum 58 of the inner rotary screen 54A. A sand screen 100 is further provided in the outlet area to further enhance the dehydration efficiency.

Here, FIG. 14 is a vertical 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, the sand screen 100 includes a frame 101 fixed to a steel base 74 and a brace 103 for suspending a main body portion 102 of the sand screen from the frame 101.
And have.

With reference to FIGS. 14 and 15, the secondary cake (F) discharged from the inner rotary screen 54A.
Is further collected on the main body 103 of the sand screen 100, and is further separated into water (I) and residual soil (H) by the vibration of the main body 103. The dehydrated water (I) is stored in the water storage tank 79. And the remaining soil (H) is abandoned in the remaining soil tank 78.

As described above, according to the dehydration treatment apparatus in the second embodiment, the secondary recovery cake discharged from the inner rotary screen is further subjected to the sand screen as compared with the dehydration treatment apparatus in the first embodiment. By dehydrating with this method, it is possible to further enhance the dehydration efficiency.

Next, a dehydration treatment apparatus according to the third embodiment of the present invention will be described with reference to FIG. Note that FIG. 16 is a diagram corresponding to the cross-sectional view of FIG. 2.

The structure of the dehydration treatment apparatus according to this embodiment is similar to that of the dehydration treatment apparatus according to the first embodiment shown in FIG. While the rotating screens 54A and 54B are structured to 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 of each other. It has a structure that allows

First, in the outer rotary screen 52, the steel plates 56 provided in the inlet region and the outlet region are supported by the roller guides 178 provided in the steel stand 74, and further, in the inlet region of the outer rotary screen 52, the sprockets 175. Is provided, and can be rotated by a drive device 70 via a roller chain 176.

On the other hand, the inner rotating screens 54A and 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 driven by a sprocket 174 provided on the rotating shaft 171.
The driving force of 70 is transmitted through the roller chain 173.

In the third embodiment having the above structure, the outer rotary screen 52 and the inner rotary screens 54A and 54B have the same rotation direction and direction as in the above-described embodiments.
Not only the same rotation speed but also the same rotation direction / left rotation, reverse rotation direction / same rotation speed, reverse rotation direction / left rotation can be realized, maximizing the dehydration rate of mud water that differs depending on the site of use. So that you can achieve
It becomes possible to adjust the muddy water treatment device. Also in this embodiment, a sand screen may be provided as shown in FIG. 14 to further enhance the dewatering effect of muddy water.

It should be understood that the above-mentioned embodiments are illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the scope of the claims, and is intended to include meanings equivalent to the scope of the claims and all modifications within the scope.

[0091]

According to the muddy water treatment apparatus of the present invention, the first rotary screen has the second rotary screen rotatable about the same axis as the first rotary screen. Thus, the treatment of muddy water can be performed while rotating the first rotary screen and the second rotary screen in the same direction or different directions depending on the condition of the muddy water, so that the dehydration can be efficiently performed.

Further, since the second rotary screen is provided inside the first rotary screen, and the first rotary screen and the second rotary screen can rotate about the same axis, the size of the muddy water treatment device can be reduced. Can be realized.

Preferably, the second rotary screen has a shape in which the opening in the exit area is smaller than the opening in the entrance area. More preferably, the bus bar located at the lowermost end of the first rotating screen descends from the inlet region to the outlet region. Further, the bus bar located at the lowermost end of the second rotating screen rises from the entrance area to the exit area. As a result, the recovered mud is processed while advancing from the inlet area to the outlet area in the first rotary screen, and is also processed while gradually advancing from the inlet area to the outlet area in the second rotary screen. Is possible.

Preferably, the inner surface of the second rotating screen has a partition plate spirally extending from the inlet region to the outlet region, and more preferably, the inner surface of the first rotating screen has the inlet region to the outlet region. It has a partition plate extending spirally. As a result, the recovered muddy water in the first rotating screen and the second rotating screen can be reliably advanced from the inlet region to the outlet region, and the processing capacity of the recovered muddy water can be improved.

Preferably, a plurality of second rotary screens are arranged in the axial direction inside the first rotary screen. As a result, it becomes possible to further improve the treatment capacity of the recovered muddy water of the second rotating screen.

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

More preferably, a wedge wire is used for the second rotary screen, and a wedge shape is formed between a plane in the axial direction of the wedge wire and the first inscribed circle or the second inscribed circle. There is. Thereby, the direction of the wedge and the rotating directions of the first and second rotary screens can be appropriately selected depending on the condition of the muddy water, and the water content contained in the recovered muddy water can be set to the optimum condition in which it easily passes through the wire net. As a result, the dewatering effect of the recovered mud water is increased, and the first and second
It is possible to further improve the processing capacity of the collected muddy water of the rotating screen.

Further, preferably, by providing a sand screen in the exit area of the second rotary screen, it becomes possible to further improve the efficiency of the dehydration treatment.

Preferably, a wedge wire is used for the first rotary screen and the second rotary screen,
Centering around the rotation axis of the rotary screen and the second rotary screen, the cross-sectional shape of the wire forming the wedge wire surrounding the axis along the direction in which the axis extends is a triangle with the bottom side facing the axis side. It is provided. Thereby, the dewatering efficiency of the recovered mud water is further improved, and the processing capacity of the recovered mud water of the first and second rotary screens can be further improved.

Next, according to the muddy water treatment method of the present invention, the recovered muddy water is separated into fine particles and primary recovered muddy water using the first rotary screen, and the primary recovered muddy water is separated using the cyclone. The muddy water is separated into the second recovered muddy water and the third recovered muddy water, and the second recovered muddy water is further dehydrated using the second rotating screen. As a result, it is possible to obtain the third recovered mud containing fine particles having a particle size smaller than the second particle size from the recovered mud, and at the same time, perform the dehydration of the second recovered mud. As a result, it becomes possible to improve the efficiency of the treatment of the recovered mud water.

[Brief description of drawings]

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

FIG. 2 is a vertical cross-sectional view of the muddy water treatment device according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of the muddy water treatment device according to the first embodiment of the present invention.

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

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

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

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

8 is a partially enlarged cross-sectional view of a region surrounded by X in FIG.

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

FIG. 10 is a cross-sectional view taken 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 according to the first embodiment of the present invention.

FIG. 12 is a vertical cross-sectional view showing another structure of the muddy water treatment device according to the first embodiment of the present invention.

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

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

FIG. 15 is a view taken along the line YY in FIG.

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

FIG. 17 is a composition diagram for explaining a muddy water treatment method using a muddy water treatment facility in the prior art.

FIG. 18 is a composition diagram for explaining components of recovered mud water.

[Explanation of symbols]

 50 Muddy water treatment device 52 Outer rotating screen 54A, 54B Inner rotating screen 56 Connecting beam 58 Exit drum 60 Entrance drum 62, 64 Guide rail 66 Guide roller 68 Non-moving gear 70 Drive device 74 Steel stand 76 Storage tank 78 Remaining soil tank 82 Cyclone 84 Pump 86 Steel plate 88A, 88B Partition plate In addition, the same code | symbol shows the same or corresponding part in the figure.

Claims (18)

[Claims] 1. A muddy water treatment device used in a muddy water construction method in which muddy water is used for excavation by an excavator, wherein an opening is provided at both ends such that one end side forms an inlet region and the other end side forms an outlet region. And a substantially cylindrical first rotating screen which is rotatable about an axis and is made of a wire mesh having a predetermined mesh size, and inside the first rotating screen is rotatable about the axis. A substantially cylindrical second rotating screen having a mesh size smaller than that of the wire mesh of the first rotating screen and having openings in the inlet region and the outlet region. And a muddy water treatment device. 2. The muddy water treatment device according to claim 1, wherein the first rotary screen and the second rotary screen are rotatable in the same direction. 3. The first rotating screen and the second rotating screen are rotatable in different directions.
The muddy water treatment device according to. 4. The muddy water treatment device according to claim 1, wherein the second rotating screen has a smaller opening in the outlet area than in the opening in the inlet area. 5. The muddy water treatment device according to claim 4, wherein a bus bar located at a lowermost end of the first rotating screen descends from the inlet region to the outlet region. 6. The muddy water treatment device according to claim 5, wherein a bus bar located at a lowermost end of the second rotating screen rises from the inlet region to the outlet region. 7. The muddy water treatment device according to claim 1, wherein a plurality of the second rotary screens are arranged in the axial direction inside the first rotary screen. 8. The muddy water treatment device according to claim 6, wherein a partition plate spirally extending from the inlet region to the outlet region is provided on an inner surface of the second rotating screen. 9. The muddy water treatment device according to claim 5, wherein a partition plate spirally extending from the inlet region to the outlet region is provided on an inner surface of the first rotating screen. 10. A wedge wire is used for the first rotary screen, and a wire rod forming the wedge wire extending in the axial direction is viewed in a rotational direction about the axis of the flat surface in a plane facing the axial direction. The first inscribed circle defined by the front end is smaller than the second inscribed circle defined by the rear end, and the first inscribed circle and the plane form a wedge shape. The muddy water treatment device according to claim 1. 11. A wedge wire is used for the first rotating screen, and a wire rod forming the wedge wire extending in the axial direction is viewed in a rotational direction about the axis of the flat surface in a plane facing the axial direction. The first inscribed circle defined by the front end is larger than the second inscribed circle defined by the rear end, and the second inscribed circle and the plane form a wedge shape. The muddy water treatment device according to claim 1. 12. A wedge wire is used for the second rotating screen, and a wire rod forming the wedge wire extending in the axial direction is viewed in a rotational direction about the axis of the flat surface in a plane facing the axial direction. The first inscribed circle defined by the front end is smaller than the second inscribed circle defined by the rear end, and the first inscribed circle and the plane form a wedge shape. The muddy water treatment device according to claim 1. 13. A wedge wire is used for the second rotary screen, and a wire rod forming the wedge wire extending in the axial direction is viewed in a rotational direction about the axis of the flat surface in a plane facing the axial direction. The first inscribed circle defined by the front end is larger than the second inscribed circle defined by the rear end, and the second inscribed circle and the plane form a wedge shape. The muddy water treatment device according to claim 1. 14. A wire rod forming a wedge wire surrounding the shaft by using a wedge wire for the first rotating screen, the cross-section taken along a direction in which the shaft extends. The muddy water treatment device according to claim 1, wherein the shape is a triangle whose base is directed toward the axis. 15. A wire rod comprising a wedge wire for the second rotating screen, the wedge wire surrounding the shaft around the shaft, the wire rod having a cross-sectional shape along a direction in which the shaft extends. The muddy water treatment device according to claim 1, wherein is a triangle whose base is directed toward the axis. 16. The muddy water treatment device according to claim 1, wherein a sand screen is provided in an exit region of the second rotary screen. 17. A muddy water treatment method for reusing recovered muddy water discharged from an excavator used in a muddy water construction method, wherein the recovered muddy water is discharged using a first screen having a predetermined mesh size. A first particle including a coarse particle having a particle diameter equal to or larger than a first particle diameter having a predetermined diameter and a fine particle having a particle diameter smaller than the first particle diameter.
A step of separating the first recovered muddy water into a second recovered muddy water, and a second step including a fine particle having a particle size equal to or larger than a second particle size smaller than the first particle size by using a wet cyclone. A step of separating the second recovered mud and a third recovered mud containing fine particles smaller than the second particle size; and a step of separating the second recovered mud with a mesh size smaller than that of the first screen. 2nd with 2 screens
A method for treating mud water, which comprises a step of separating the next recovered cake and water. 18. The muddy water treatment method according to claim 17, further comprising the step of dewatering the secondary recovered cake using a sand screen.