Dehydrator

Abstract

To provide a dehydrator capable of suppressing clogging.SOLUTION: A dehydrator according to the present invention is provided with a regulation plate 4 at a position in a proximity of and opposed to a dehydration screen 2, extending from a top end 16 of a sand housing part 1 to a side of a bottom wall 10 for regulating a flow of sand ES in a sand housing part 1 to the side of the dehydration screen 2. By this, the sand ES accommodated in the sand housing part 1 is, on spreading in the horizontal direction by a weight of the sand (soil pressure), stopped by the regulation plate 4 in a height area where the regulation plate 4 is placed, and the sand flows to the side of the dehydration screen 2 via a space S between the regulation plate 4 and the bottom wall 10. By this, most of the soil pressure of the sand ES in the sand housing part 1 affects on the regulation plate 4 thus there is no fear of a direct action to the dehydration screen 2, and clogging of the dehydration screen 2 can be suppressed.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a dewatering apparatus used for dewatering mud (industrial waste) lifted up during, for example, the submergence excavation of a vertical shaft. [Background technology]

[0002] 2. Description of the Related Art A conventional dehydrator is disclosed in, for example, Patent Document 1 below.

[0003] That is, in the past, a filter member was provided in a bucket used for unloading soil, and dewatering was carried out through the filter member when unloading soil. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-009527 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the conventional dewatering device, the soil pressure acting on the filter member causes mud to get into the gaps in the filter member, causing the filter member to become clogged. In addition, the clogged filter member needs to be washed with high pressure or replaced, resulting in both work and economic burdens. Thus, the conventional dewatering device in which the filter member is provided in the bucket leaves room for improvement in terms of the problem of the filter member becoming clogged.

[0006] The present invention has been devised in view of the above technical problem, and has an object to provide a dewatering device capable of suppressing clogging. [Means for solving the problem]

[0007] In one embodiment, the dewatering device of the present invention comprises a soil storage section having a generally rectangular bottom wall and first, second, third and fourth side walls rising from each of the side edges of the bottom wall, the soil storage section having an open top, a dewatering screen provided on the first side wall and capable of discharging muddy water contained in the soil stored in the soil storage section while suppressing the outflow of the soil stored in the soil storage section, a water tank for storing the muddy water drained through the dewatering screen, and a regulating plate arranged inside the soil storage section so as to face closely to the dewatering screen, the regulating plate extending from the top end of the soil storage section toward the bottom wall to form a predetermined gap between the soil storage section and the bottom wall, and regulating the flow of soil stored in the soil storage section that is located above the gap toward the dewatering screen.

[0008] Thus, according to the present invention, a restricting plate is provided in a position adjacent to and facing the dewatering screen, extending from the top end of the soil storage section toward the bottom wall, for restricting the flow of soil from the soil storage section toward the dewatering screen. As a result, when the soil stored in the soil storage section spreads horizontally due to the weight of the soil (soil pressure), the soil is blocked by the restricting plate in the height region where the restricting plate is located, and flows toward the dewatering screen through the gap between the restricting plate and the bottom wall. In other words, most of the soil pressure of the soil in the soil storage section acts on the restricting plate and is not likely to act directly on the dewatering screen, so clogging of the dewatering screen can be suppressed.

[0009] In addition, the soil that flows toward the dewatering screen through the gap between the regulating plate and the bottom wall acts only on the lower end area of ​​the dewatering screen facing the gap. As a result, the muddy water contained in the soil can flow around the lower side of the regulating plate through the gap and can be drained not only from the lower end area of ​​the dewatering screen facing the gap, but also from the upper side of the soil facing the dewatering screen, that is, the upper end area of ​​the dewatering screen facing the regulating plate. This allows the muddy water to be discharged from areas of the dewatering screen that are not reached by the soil, improving the drainage of the muddy water. In other words, even if a part of the dewatering screen (the lower end area) is clogged with soil, good drainage of the muddy water can be ensured through the upper end area of ​​the dewatering screen where the soil does not act.

[0010] Furthermore, by providing a restricting plate closely facing the dewatering screen, there is no risk of the shovel's claws coming into direct contact with the dewatering screen when the soil in the soil storage unit is shoveled up and dumped. This means there is no risk of the shovel's claws damaging the dewatering screen, protecting it when dumping soil and extending its lifespan.

[0011] In addition, as another aspect of the dewatering device, it is desirable that the dewatering screen is formed by overlapping a mesh wire netting facing the inside of the first side wall and capable of discharging the muddy water while suppressing the outflow of the soil contained in the soil storage section, and an expanded metal that is positioned outside the mesh wire netting in the thickness direction of the first side wall and reinforces the mesh wire netting.

[0012] In this way, the dewatering screen is composed of a wire mesh and an expanded metal layer placed on the outside of the wire mesh, so that the wire mesh, which is made of a relatively small wire diameter and vulnerable to earth pressure, is reinforced by the expanded metal, which is made of a relatively large wire diameter and strong against earth pressure. This improves the strength (rigidity) of the dewatering screen and prevents deformation or damage to the dewatering screen.

[0013] In yet another embodiment of the dehydrator, the mesh wire screen is desirably made up of 10 to 30 meshes.

[0014] In this way, by configuring the mesh wire screen with 10 to 30 meshes, clogging of the mesh wire screen is suppressed, the permeation of fine soil particles is effectively suppressed, and a relatively large amount of water can be discharged, which effectively improves the dewatering performance of the dewatering screen.

[0015] In yet another aspect of the dewatering device, it is preferable that the mesh wire screen is divided into two parts in the width direction, with one side having a different mesh size than the other side.

[0016] In this way, by configuring the mesh wire netting with different mesh sizes on one side and the other side of the width of the mesh wire netting, it is possible to effectively suppress the permeation of fine soil particles while improving drainage.

[0017] In addition, as yet another aspect of the dewatering device, it is desirable that the regulating plate is arranged parallel to the first side wall or inclined so as to approach the first side wall from the top end of the soil storage section toward the bottom wall.

[0018] In this way, the restricting plate is parallel to the first side wall or inclined so as to approach the first side wall from the top end of the soil storage section toward the bottom wall. In this way, by adjusting the angle of the restricting plate, it is possible to adjust the amount of soil flowing through the gap toward the dewatering screen. This makes it possible to adjust the soil pressure acting on the dewatering screen while ensuring good soil flowability, and effectively achieves both protection of the dewatering screen and dewatering performance.

[0019] In yet another aspect of the dewatering device, it is desirable that the regulating plate extends from the top of the soil storage section to a depth position approximately two-thirds of the first side wall, and that the gap is set at a height position approximately one-third of the first side wall from the bottom wall.

[0020] In this way, the restricting plate extends from the top end of the soil storage section to a depth of about two-thirds of the first side wall, and the gap is set at a height of about one-third of the first side wall from the bottom wall. In this way, by adjusting the extension amount of the restricting plate and the height of the gap, it is possible to adjust the amount of soil flowing through the gap toward the dewatering screen. This makes it possible to adjust the soil pressure acting on the dewatering screen while ensuring good soil fluidity, effectively achieving both protection of the dewatering screen and dewatering performance.

[0021] In yet another aspect of the dewatering device, it is desirable that the water tank be arranged adjacent to the outside of the first side wall, and that the muddy water drained into the water tank be discharged to the outside by a pump.

[0022] In this manner, the muddy water drained into the water tank is discharged to the outside by the pump, so that the muddy water drained into the water tank can be efficiently discharged to the outside.

[0023] As yet another aspect of the dewatering device, it is desirable that the soil stored in the soil storage section be scooped up toward the second side wall opposite the first side wall by a shovel entering from the top of the soil storage section along the side of the regulating plate opposite the dewatering screen.

[0024] In this way, by having the shovel enter along the inner surface of the restricting plate and scoop up the soil toward the second side wall, the height of the soil facing the first side wall through the gap is lowered by the shovel's scooping up, and a water path is secured for the muddy water mixed with the soil through the gap to the first side wall. This water path allows the muddy water to be guided to the dewatering screen side, and the muddy water can be efficiently drained. In addition, in this case, because the shovel enters along the restricting plate, collisions between the shovel and the dewatering screen can also be suppressed. Effect of the Invention

[0025] According to the present invention, when the soil contained in the soil storage section spreads horizontally due to its own weight (soil pressure), most of the soil pressure acts on the regulating plate and is not likely to act directly on the dewatering screen, thereby making it possible to prevent clogging of the dewatering screen. [Brief description of the drawings]

[0026] [Figure 1] 1 is a schematic cross-sectional view of a dewatering device according to the present invention. [Diagram 2] FIG. 2 is an exploded perspective view of the dewatering screen shown in FIG. [Diagram 3] 3 is a partial cross-sectional view in the thickness direction of the dewatering screen shown in FIG. 2. [Figure 4] 1A and 1B are schematic cross-sectional views of a dewatering device according to the present invention, in which FIG. 1A shows a state in which there is little soil in a soil storage section, and FIG. 1B shows a state in which the soil storage section is almost full. [Diagram 5] 1A and 1B are schematic perspective views of a dewatering device according to the present invention, showing a state in which there is little soil in a soil storage section, and FIG. 1B shows a state in which the soil storage section is almost full. [Figure 6] FIG. 2 is a schematic perspective view of a dewatering device according to the present invention, showing how soil is discharged from a soil storage section. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a dewatering apparatus according to the present invention will be described in detail with reference to the accompanying drawings. In the following preferred embodiments, the present invention will be described as being applied to the sinking excavation of a vertical shaft.

[0028] (Configuration of the dehydration device) FIG. 1 is a schematic diagram of a dehydration device according to the present invention, showing a cross-sectional view of the dehydration device cut along the longitudinal direction.

[0029] As shown in Figure 1, the dewatering device of this embodiment comprises a soil storage section 1 for storing soil ES (see Figure 5) unloaded, for example, by a clam bucket CB (see Figure 5), a dewatering screen 2 provided on one side wall of the soil storage section 1 (first side wall 11 in this embodiment), a water tank 3 for storing muddy water MW (see Figure 5) filtered by the dewatering screen 2, and a regulating plate 4 arranged opposite the first side wall 11 in the soil storage section 1 for regulating the flow of soil ES toward the dewatering screen 2.

[0030] The soil storage section 1 is formed in a rectangular tube shape with a bottom, and includes a generally rectangular bottom wall 10 and a first side wall 11, a second side wall 12, a third side wall 13, and a fourth side wall 14 (see FIG. 5) that rise vertically from the sides of the bottom wall 10, and is open at the top. The bottom wall 10 may be rectangular, and may be square or rectangular, but is preferably formed in a rectangular shape that extends relatively long along the moving direction of a hydraulic excavator PS (see FIG. 6) described later, as in this embodiment shown in FIG. 1. In this embodiment, the first side wall 11 and the second side wall 12 are arranged on the short sides of the bottom wall 10, and the third side wall 13 and the fourth side wall 14 are arranged on the long sides.

[0031] The bottom wall 10 of the soil storage section 1 is disposed at a relatively high position in the vertical direction with respect to the bottom wall 30 of the water tank 3 described below, and is placed on a support stand 15 having a predetermined height, as shown in Fig. 1 for example. The height of the support stand 15 is set to an arbitrary height depending on, for example, the depth of the water tank 3. The support stand 15 may be provided as a single unit, or may be divided into a plurality of units as shown in Fig. 1.

[0032] The dewatering screen 2 is disposed on one of the side walls 11, 12, 13, and 14 of the soil storage section 1 that is adjacent to the water tank 3, which is the first side wall 11 in this embodiment. The dewatering screen 2 enables the discharge of muddy water MW contained in the soil ES stored in the soil storage section 1 while suppressing the outflow of the soil ES stored in the soil storage section 1. The specific configuration of the dewatering screen 2 will be described in detail later with reference to FIG. 2.

[0033] The water tank 3 is, for example, a well-known vessel. Specifically, the water tank 3 has a generally rectangular bottom wall 30 arranged at a position relatively lower than the bottom wall 10 of the soil storage section 1 in the vertical direction, an inclined wall 31 extending from a screen-facing edge 30a of the bottom wall 30 adjacent to and facing the dewatering screen 2 toward the first side wall 11, and a vertical wall 32 rising generally vertically from the other three sides of the bottom wall 30 excluding the screen-facing edge 30a. The muddy water that has passed through the dewatering screen 2 is guided to the water tank 3 along the inclined wall 31. The water tank 3 is also provided with a drainage pump DP, and the muddy water MW guided to the water tank 3 via the pump DP can be drained to the outside.

[0034] The regulating plate 4 has a width equal to that of the first side wall 11, and is disposed such that a first end 41, which is one end in the vertical direction, is fixed to the top edge 16 of the soil storage section 1, and a second end 42, which is the other end, faces the bottom wall 10 across a specified gap S. The regulating plate 4 may be disposed parallel to the first side wall 11 (the dewatering screen 2). In addition to such a parallel arrangement, it is desirable that the second end 42 be disposed at an angle so as to gradually approach the first side wall 11 (the dewatering screen 2), as in the present embodiment shown in Fig. 1.

[0035] Moreover, the second end 42 of the regulating plate 4 extends in the vertical direction from the top end 16 (the upper ends of the third side wall 13 and the fourth side wall 14) of the soil storage section 1 to a depth position that is about two-thirds of the first side wall 11. In other words, the extension amount of the second end 42 of the regulating plate 4 is set so that the gap S in the vertical direction is about one-third the height of the first side wall 11 from the bottom wall 10. Moreover, the regulating plate 4 is disposed so that the second end 42 is spaced about one meter from the first side wall 11.

[0036] (Dewatering screen configuration) Fig. 2 shows an exploded perspective view of the dewatering screen 2 shown in Fig. 1. Fig. 3 shows a partial cross-sectional view of the upper end portion of the dewatering screen 2 shown in Fig. 2 cut in the thickness direction. For convenience, the cross sections of the mesh wire netting 21 and the expanded metal 22 are shown hatched in Fig. 2.

[0037] 2 and 3, the dewatering screen 2 is mainly composed of a mesh wire netting 21, an expanded metal 22, a spacer 23, and a pair of frames 241, 242. Specifically, the dewatering screen 2 is overlapped with the mesh wire netting 21 on the inside and the expanded metal 22 on the outside, and a spacer 23 is disposed on the outer periphery of the overlapped mesh wire netting 21 and expanded metal 22. The mesh wire netting 21 and the expanded metal 22 are sandwiched together with the spacer 23 by the pair of frames 241, 242.

[0038] The mesh wire netting 21 faces the inside of the first side wall 11 and has a function of discharging the muddy water MW while suppressing the outflow of the sediment ES stored in the sediment storage section 1. The mesh wire netting 21 is selected to have a mesh size suitable for the soil quality (soil particles) of the sediment ES to be dewatered, but is preferably set to about 10 to 30 mesh. Here, the mesh wire netting 21 may be integrally formed as a whole, or may be divided into two in the width direction, as shown in FIG. 2. In this case, as shown in FIG. 2, the mesh wire netting 21 can have different mesh sizes (10 to 30 mesh) for the first mesh wire netting 211 on one side in the width direction and the second mesh wire netting 212 on the other side. In this embodiment, the mesh size of the first mesh wire netting 211 on one side is set to 10 mesh, and the mesh size of the second mesh wire netting 212 on the other side is set to 20 mesh.

[0039] The expanded metal 22 is disposed overlapping the mesh wire netting 21 on the outside in the thickness direction of the first side wall 11, and has a wire diameter (e.g., 19 mm) sufficiently larger than the wire diameter (e.g., 1 mm) of the mesh wire netting 21 as shown in Fig. 3, and has a function of reinforcing the mesh wire netting 21. Moreover, the expanded metal 22 is set to a mesh size sufficiently larger than that of the mesh wire netting 21 so as not to impede the passage of the muddy water MW that has passed through the mesh wire netting 21, while reinforcing the mesh wire netting 21 (see Fig. 2).

[0040] The spacer 23 has a rectangular frame shape capable of housing the mesh wire netting 21 and the expanded metal 22 inside, and is set to a thickness (e.g., 19 mm) equal to the thickness of the overlapping mesh wire netting 21 and the expanded metal 22. The spacer 23 is provided with a predetermined fastening means for fastening the pair of frames 241, 242, i.e., a plurality of through holes 230 through which the shafts 25a of the bolts 25 in this embodiment can pass, and has a function of receiving the axial force of the bolts 25 fastening the pair of frames 241, 242.

[0041] The pair of frames 241, 242 are formed to a predetermined thickness (for example, 6 mm) from a metal material that is relatively resistant to rust, such as aluminum or stainless steel, and are formed into a roughly rectangular frame shape whose outer side matches the outer shape of the spacer 23 and whose inner side overlaps with the outer periphery of the mesh metal netting 21 and the expanded metal 22 in the thickness direction. Furthermore, the pair of frames 241, 242 are provided with a plurality of through holes 240 through which the shafts 25a of the bolts 25 can penetrate, at positions corresponding to the through holes 230 of the spacer 23. That is, the pair of frames 241, 242 sandwich the mesh metal netting 21 and the expanded metal 22 together with the spacer 23, and thereby have a function of sandwiching the mesh metal netting 21 and the expanded metal 22 by the fastening force of the bolts 25 and nuts 26, which are fastening means. In addition, in this embodiment, the pair of frames 241, 242 have intermediate sashes 241a, 242a extending vertically in the center of the width direction. That is, a pair of frames 241, 242 have two windows in the width direction, a first window portion W1 and a second window portion W2 (see Figure 2), via intermediate sashes 241a, 242a, and a first mesh wire mesh 211 is arranged in the first window portion W1, and a second mesh wire mesh 212 is arranged in the second window portion W2.

[0042] (Soil dehydration process) FIG. 4 is a schematic cross-sectional view of the dewatering device according to the present embodiment, showing the dewatering process by the dewatering device, where (a) shows a state in which the amount of sediment ES in the sediment storage section 1 is relatively small, and (b) shows a state in which the sediment ES in the sediment storage section 1 is almost full. FIG. 5 is a schematic perspective view of the dewatering device according to the present embodiment, showing the dewatering process by the dewatering device, where (a) shows a state in which the amount of sediment ES in the sediment storage section 1 is relatively small, and (b) shows a state in which the sediment ES in the sediment storage section 1 is almost full. FIG. 6 is a schematic perspective view of the dewatering device according to the present embodiment, showing the process of discharging the sediment ES in the sediment storage section 1 by the hydraulic excavator PS. In addition, in FIG. 4, FIG. 5, and FIG. 6, for convenience, the first side wall 11 and the fourth side wall 14 are made transparent so that the sediment ES and muddy water MW inside can be seen through.

[0043] The soil ES lifted up by the cram bucket CB is stored in the soil storage section 1. At this time, the soil ES lifted up by the cram bucket CB is discharged to a position away from the restricting plate 4 in the longitudinal direction of the soil storage section 1, that is, to a position close to the second side wall 12 of the soil storage section 1, as shown in Figures 4(a) and 5(a).

[0044] 4(a) and 5(a), when there is a relatively small amount of sediment ES in the sediment storage section 1, i.e., when the sediment ES is not in contact with the restricting plate 4, the sediment ES spreads horizontally due to its weight and gradually moves toward the first side wall 11, but as shown in Fig. 4(a), it comes into slight contact with the lower end of the dewatering screen 2. In this state, most of the sediment ES is not in contact with the dewatering screen 2, so there is no risk of the dewatering screen 2 becoming clogged with the sediment ES, and the muddy water MW contained in the sediment ES is smoothly filtered by the dewatering screen 2 and flows into the water tank 3.

[0045] As the amount of sediment ES in the sediment storage section 1 increases, as shown in FIG. 4(b) and FIG. 5(b), when the sediment ES spreads horizontally due to its own weight, the sediment ES comes into contact with the regulating plate 4 and is blocked by the regulating plate 4 in the height region where the regulating plate 4 is located. As a result, the movement of the sediment ES in the sediment storage section 1 toward the first side wall 11 is restricted by the regulating plate 4, and only the portion that passes through the gap S between the regulating plate 4 and the bottom wall 10 moves toward the first side wall 11. As a result, as shown in FIG. 4(b), the sediment ES comes into slight contact with the lower end of the dewatering screen 2. That is, in this state, most of the sediment ES does not come into contact with the dewatering screen 2, and the dewatering screen 2 is less likely to become clogged with the sediment ES. The muddy water MW contained in the sediment ES is filtered relatively smoothly by the dewatering screen 2 and flows into the water tank 3.

[0046] Furthermore, when the amount of sediment ES in the sediment storage section 1 increases, for example as shown in FIG. 6, the hydraulic excavator PS scoops up the sediment ES in the sediment storage section 1 from a position near the gap S between the restricting plate 4 and the bottom wall 10 toward the second side wall 12. The scooped up sediment ES is then transported to a transport vehicle (not shown) and transported to a predetermined soil disposal site by the transport vehicle. Here, the hydraulic excavator PS removes the sediment ES located near the gap S, thereby securing a water path for the muddy water MW mixed with the sediment ES from the gap S to the first side wall 11. This water path allows the muddy water MW in the sediment storage section 1 to be smoothly guided through the gap S toward the first side wall 11. In addition, when the hydraulic excavator PS performs the above-mentioned scooping, it enters the soil storage section 1 along the inner surface of the regulating plate 4 (the surface facing opposite the first side wall 11), thereby reducing contact between the hydraulic excavator PS and the dewatering screen 2 and preventing damage to the dewatering screen 2 by the hydraulic excavator PS.

[0047] (Effects of this embodiment) The characteristic functions and effects achieved by the dehydration device according to this embodiment will be specifically described below.

[0048] In the conventional dewatering device, the soil pressure acting on the filter element causes mud to get into the gaps in the filter element, causing the filter element to become clogged. In addition, the clogged filter element needs to be washed with high pressure or replaced, which results in both labor and economic burdens. Thus, the conventional dewatering device leaves room for improvement in terms of the problem of the filter element becoming clogged.

[0049] In contrast, the dewatering device according to this embodiment is provided with a restricting plate 4 that extends from the top end 16 of the soil storage section 1 toward the bottom wall 10 at a position adjacent to and facing the dewatering screen 2 and restricts the flow of the soil ES in the soil storage section 1 toward the dewatering screen 2. As a result, when the soil ES stored in the soil storage section 1 spreads horizontally due to the weight of the soil (soil pressure), the soil is blocked by the restricting plate 4 in the height region where the restricting plate 4 is located, and flows toward the dewatering screen 2 through the gap S between the restricting plate 4 and the bottom wall 10. As a result, most of the soil pressure of the soil ES in the soil storage section 1 acts on the restricting plate 4 and is not likely to act directly on the dewatering screen 2, so clogging of the dewatering screen 2 can be suppressed.

[0050] In addition, the sediment ES that flows toward the dewatering screen 2 through the gap S between the regulating plate 4 and the bottom wall 10 acts only on the lower end region of the dewatering screen 2 that faces the gap S. As a result, the muddy water MW contained in the sediment ES flows around the lower side of the regulating plate 4 through the gap S, and can be drained not only from the lower end region of the dewatering screen 2 that faces the gap S, but also from the upper side of the sediment ES facing the dewatering screen 2, i.e., the upper end region of the dewatering screen 2 that faces the regulating plate 4. This allows the muddy water MW to be discharged from the region of the dewatering screen 2 that is not reached by the sediment ES, thereby improving the drainage of the muddy water MW. In other words, even if a part of the dewatering screen 2 (the lower end region) is clogged with the sediment ES, good drainage of the muddy water MW can be ensured through the upper end region of the dewatering screen 2 where the sediment ES does not act.

[0051] Furthermore, because the restricting plate 4 is provided closely facing the dewatering screen 2, when the hydraulic excavator PS scoops up and discharges the soil ES inside the soil storage section 1, there is no risk of the tines of the hydraulic excavator PS coming into direct contact with the dewatering screen 2. As a result, there is no risk of the tines of the hydraulic excavator PS damaging the dewatering screen 2, which protects the dewatering screen 2 during soil discharge and makes it possible to extend the life of the dewatering screen 2.

[0052] In this embodiment, the dewatering screen 2 is composed of a mesh wire netting 21 and an expanded metal 22 arranged overlapping the outer side of the mesh wire netting 21. Therefore, the mesh wire netting 21, which is made of a relatively small mesh with a thin wire diameter and is vulnerable to earth pressure, is reinforced by the expanded metal 22, which is made of a relatively large mesh with a thick wire diameter and is strong against earth pressure. This improves the strength (rigidity) of the dewatering screen 2, making it possible to prevent deformation or damage to the dewatering screen 2.

[0053] In this embodiment, the mesh wire netting 21 is made of 10 to 30 meshes. This effectively prevents the mesh wire netting 21 from clogging while effectively preventing the permeation of fine soil particles, and allows a relatively large amount of water (muddy water MW) to be discharged. This effectively improves the dewatering performance of the dewatering screen 2.

[0054] In this embodiment, the mesh wire netting 21 is configured with different mesh sizes on one side and the other side in the width direction of the mesh wire netting 21. This makes it possible to effectively suppress the permeation of fine soil particles and improve drainage.

[0055] Furthermore, in this embodiment, the restricting plate 4 is parallel to the first side wall 11 or inclined so as to approach the first side wall 11 from the top end 16 of the soil storage section 1 toward the bottom wall 10. In this way, by adjusting the angle of the restricting plate 4, it is possible to adjust the amount of soil ES flowing through the gap S toward the dewatering screen 2. This makes it possible to adjust the soil pressure acting on the dewatering screen 2 while ensuring good fluidity of the soil ES, and effectively achieves both protection of the dewatering screen 2 and dewatering performance.

[0056] Furthermore, in this embodiment, the restricting plate 4 extends from the top end 16 of the soil storage section 1 to a depth position that is approximately two-thirds of the depth of the first side wall 11, and the gap S is set to a height position that is approximately one-third of the depth of the first side wall 11 from the bottom wall 10. In this way, by adjusting the extension amount of the restricting plate 4 and the height dimension of the gap S, it is possible to adjust the amount of soil ES flowing through the gap S toward the dewatering screen 2. This makes it possible to adjust the soil pressure acting on the dewatering screen 2 while ensuring good fluidity of the soil ES, and effectively achieves both protection of the dewatering screen 2 and dewatering performance.

[0057] In this embodiment, the muddy water drained into the water tank 3 is discharged to the outside by the pump DP. This allows the muddy water MW drained into the water tank 3 to be efficiently discharged to the outside.

[0058] Furthermore, in this embodiment, by having the hydraulic excavator PS enter along the inner surface of the regulating plate 4 and scoop up the soil ES toward the second side wall 12, the height of the soil ES facing the first side wall 11 from the gap S is lowered by the scooping up of the hydraulic excavator PS, and a water path is secured for the muddy water MW mixed with the soil ES from the gap S to the first side wall 11 side. This water path makes it possible to guide the muddy water MW to the dewatering screen 2 side, and the muddy water MW can be efficiently drained. Furthermore, in this case, because the hydraulic excavator PS enters along the regulating plate 4, collision between the hydraulic excavator PS and the dewatering screen 2 can also be suppressed.

[0059] The present invention is not limited to the configurations exemplified in the above-described embodiments, and can be freely modified according to the specifications of the target object within the scope of the present invention. [Explanation of symbols]

[0060] 1...Soil storage section 10…Bottom wall 11…First side wall 12…Second side wall 13…Third side wall 14…Fourth side wall 16…Top 2. Dewatering screen 21…Mesh wire netting 22…Expanded metal 3. Water tank 4. Restriction board 41...First end 42…Second end ES…Sediment MW…muddy water S…Gap DP…Pump PS: Hydraulic excavator (shovel)

Claims

1. A soil storage section having a generally rectangular bottom wall and a first side wall, a second side wall, a third side wall, and a fourth side wall rising from each side edge of the bottom wall, the soil storage section having an open top; A dewatering screen is provided on the first side wall and is capable of discharging muddy water contained in the soil contained in the soil storage section while suppressing outflow of the soil contained in the soil storage section; a water tank for storing the muddy water drained through the dewatering screen; a restricting plate disposed inside the soil storage section so as to face closely to the dewatering screen, extending from the top end of the soil storage section toward the bottom wall to form a predetermined gap between the bottom wall and the restricting plate, which restricts the flow of soil stored in the soil storage section that is located above the gap toward the dewatering screen; Equipped with A dehydration device characterized by:

2. The dewatering device according to claim 1, The dewatering screen comprises: a mesh wire netting facing the inside of the first side wall and capable of discharging the muddy water while suppressing the outflow of the soil contained in the soil containing section; an expanded metal arranged outside the mesh wire in a thickness direction of the first side wall and reinforcing the mesh wire; It is formed by overlapping A dehydration device characterized by:

3. The dewatering device according to claim 2, The mesh wire netting is composed of 10 to 30 meshes. A dehydration device characterized by:

4. The dewatering device according to claim 3, The mesh wire netting is divided into two parts in the width direction, and one side and the other side are configured with different mesh sizes. A dehydration device characterized by:

5. The dewatering device according to claim 1, The regulating plate is arranged parallel to the first side wall or inclined so as to approach the first side wall from the top end of the soil storage section toward the bottom wall, A dehydration device characterized by:

6. The dewatering device according to claim 5, The regulating plate extends from the top end of the soil storage section to a depth position of about two-thirds of the first side wall, The gap is set at a height position that is approximately one-third of the height of the first side wall from the bottom wall. A dehydration device characterized by:

7. The dehydrator according to any one of claims 1 to 6, The water tank is disposed adjacent to an outer side of the first side wall, The muddy water drained into the water tank is discharged to the outside by a pump. A dehydration device characterized by:

8. The dehydrator according to any one of claims 1 to 6, The soil stored in the soil storage section is shoveled up from the top of the soil storage section along the side of the regulating plate opposite the dewatering screen toward the second side wall opposite the first side wall. A dehydration device characterized by:

Images