JPH0639398A - Method and apparatus for dehydration of sludge, and dehydration plate - Google Patents

Abstract

PURPOSE:To dehydrate a large amt. of sludge etc., with reduced treating cost, efficiently and surely. CONSTITUTION:In a filling space surrounded by filter plates 10 and 10' facing each other while a required gap is held and gap holding frames 11 and 11', a sludge wherein a specified amt. of a cement is added in advance, is filled under pressure and water in the sludge S etc., is dehydrated by performing vacuum suction through the filter plates 10 and 10' from the outside of the filling space while this filling under pressure is continued.

Description

Detailed Description of the Invention

[0001]

[Field of Industrial Application] The present invention dehydrates sludge generated in construction work, pile foundation construction method, underground continuous wall construction method, mud shield construction method, and other sludge such as surplus mud water and waste mud by ground improvement method. However, the present invention relates to a dehydration method and apparatus for reducing the water content ratio, and a dehydration plate thereof.

[0002]

2. Description of the Related Art Generally, cohesive soil containing silt by excavation, mud produced by dredging, and excavated mud produced by the mud shield method have a very high water content ratio. It is treated as waste, and in order to discard it, it is desirable to reduce the water content and treat it as ordinary residual soil.

As a conventional method for treating sludge and the like, a method of mixing and agitating cement-based or lime-based solidifying agents has been carried out, but in order to treat a large amount of sludge etc., a solidifying agent is used. A large amount of material cost is required.

Conventionally, sludge and the like is put in a drainage pit provided underground, and the water content is drained to a bottom filtration layer composed of crushed stones, mesh pipes, etc. and pumped up by a water absorption pipe to obtain a water content ratio. A method of lowering and treating as ordinary residual soil is also known, but this method uses natural gravity drainage, so the drainage distance and time are long and inefficient, and the filter layer is easily clogged and its maintenance is easy. There was a problem such as not.

Therefore, the applicants first put sludge or the like in the dehydration tank to hermetically seal it, and penetrate a large number of strainer pipes into the sludge or the like inside to give vibration to the dehydration tank to remove moisture. A dehydrating device was developed in which the water was exuded and the water was discharged to the outside by vacuum suction through a strainer tube, and it has already been filed as Japanese Patent Application No. Sho 63-178342.

However, in the vacuum suction method using a strainer tube, the portion that comes into contact with sludge and absorbs water is the outer peripheral portion of the strainer tube, so there is a limit to the water absorption range,
The water absorption efficiency is poor, and the dewatering effect of the central part of sludge and the like in the dewatering tank is relatively good, but the dewatering effect of the periphery is insufficient, and there is a problem that the water cannot be dewatered uniformly as a whole.

Further, there is a problem that only by vacuum suction, the dehydration efficiency is lowered when the inside is in a vacuum equilibrium state.

[0008]

SUMMARY OF THE INVENTION The present invention has a problem that the conventional method using a solidifying agent is costly, and that a drainage pit having a bottom filtration layer has poor drainage efficiency and maintenance is not easy. The object of the present invention is to solve the problem that the vacuum suction method using a strainer tube cannot uniformly dehydrate as a whole.

[0009]

According to the present invention, a predetermined amount of cement is preliminarily filled in a filling space surrounded by filter plates 10 and 10 'which face each other while holding a required gap and gap holding frames 11 and 11 around the gap. The added sludge S or the like is pressure-filled, and while continuing the pressure-filling, the filter plate 1 is placed from the outside of the filling space.
By vacuum suction through 0, 10 ', sludge etc. S
It proposes a method for dehydrating sludge and the like so as to dehydrate the water content therein.

Further, according to the present invention, a plurality of dewatering plates 5a, (5b) slidably supported on a horizontal guide rail 4 are provided.
5c are stacked on top of each other and pressure-bonded in an airtight manner, and adjacent dehydration plates 5
a, (5b), 5c filter plate 1 provided on the mutually facing surface
A filling space surrounded by the peripheral gap holding frames 11 and 11 is provided between 0 and 10 ′, and the dehydration plates 5a and (5
b) and 5c, the filter plates 10 and 10 'have a core plate 9,
9'is supported by the edge frame 14 and the projections 16 provided on the stepped concave surface 15 on the inner side thereof, and the dehydration plates 5a, (5
In b) and 5c, an injection hole 1 for sludge or the like S communicating with the filling space 1
2 and a series of suction holes 13 communicating with the filter plates 10 and 10 ′ and the suction space of the stepped concave surface 15.
Is a device for dehydrating sludge or the like, which is connected to a supply pipe for pumping sludge S or the like, and the suction hole 13 is connected to a vacuum suction pipe.

Further, according to the present invention, the edge frames 14 are provided at the peripheral portions of the front and back surfaces, and a large number of projections 16 having substantially the same height as the edge frames 14 are provided on the step concave surface 15 inside the edge frames 14. The core plates 9 and 9 ', the filter plates 10 and 10' which are attached to the edge frames 14 of the core plates 9 and 9'in close contact with the periphery, and formed in a frame shape along the periphery of the core plates 9 and 9 '. And a gap holding frame 11 that is closely attached to the edge frame 14 of the core plates 9 and 9'on the periphery thereof. The edge frame 14 and the gap holding frame 11 are provided with injection holes 12 that penetrate them in series. The lower end of the step concave surface 15 and the gap holding frame 11 are provided with a suction hole 13 that penetrates them in series.
The injection hole 12 is provided around the injection hole 12 of the gap holding frame 11.
From the inner peripheral edge of the gap to the inner peripheral edge of the gap holding frame 11
7 is formed, and a plurality of projections 16 are continuously arranged in series on the step concave surface 15 of the core plates 9 and 9 ′ at a small interval, and a dehydration plate for sludge or the like is provided in which a plurality of the projection rows are provided in the intersecting direction with each other. To do.

[0012]

The water in the sludge S filled in the filling space under pressure is filtered outside the filling space through the filter plates 10 and 10 'which are in contact with the sludge S as wide surfaces parallel to each other. By applying a vacuum suction force from the above, the water is strongly separated from the solid content and dehydrated by the interaction with the filling pressure from the inside which acts at the same time.

Further, since the sludge S is continuously charged under pressure during the dehydration, the sludge S is removed by dehydration.
Even if the volume is reduced, the reduced amount of sludge or the like S is surely replenished in the filling space, and the sludge or the like S does not always fill the filling space in a compacted manner to form a cavity.

As a result, when the pressure filling is not continued, the suction dewatering efficiency does not deteriorate due to the cavitation due to the volume reduction of the sludge S.

By adding a predetermined amount of cement to the sludge and the like prior to dehydration, the fine particles of soil are consolidated and coarsened to facilitate dehydration.

By suctioning the inside of the dehydration plate under a vacuum while applying a filling pressure to the sludge S filled in the filling space, the water contained in the sludge S in each filling space is efficiently and uniformly as a whole. Be sucked and dehydrated.

In this case, it is possible to dehydrate only with the pressure of pressure filling, but with this pressure dehydration alone, as the solid content becomes harder with dehydration, the pressure becomes less likely to be transmitted to the whole sludge and the like. As a result, sufficient dehydration cannot be performed, and in the end, it is found that the combined use of the filling pressure and the vacuum suction force is extremely effective for dehydration.

After the completion of the dehydration process, the hydraulic cylinder 7 is contracted to retract the rear end dehydration plate 5c through the pressure plate 7 so that the adjacent dehydration plates 5a, (5b) and 5c are connected to each other by the length of the connecting cable 18. The dewatered earth and sand are discharged between the dehydration plates 5a, (5b) and 5c by vibration or the like by sequentially separating the dewatering plates by a distance.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the dehydrator according to the present invention and a dehydrator plate used therein. As shown in FIGS. 1 and 2, a base 1 of the dehydrator is provided with a pressurizing base 2 and a receiving base 3. Are installed at predetermined intervals, and a guide rail 4 is horizontally mounted between the side surfaces of the pressurizing base 2 and the receiving base 3, and a plurality of dehydrating plates 5a, 5b, 5c are mounted on the guide rail 4. Are supported slidably by engaging hook-shaped suspensions 6 provided on both sides thereof.

This dehydration plate is one in which two or more intermediate dehydration plates 5b are superposed on each other between a front dehydration plate 5a and a rear end dehydration plate 5c, and a hydraulic cylinder 7 provided on the pressurizing table 2 in the dehydration process. By the extension operation of (1), the pressure plate 8 attached to the tip of the rod presses it, and the pressure plate 8 and the pedestal 3 are pressed and held to each other.

As shown in FIGS. 5 and 6, the intermediate dewatering plate 5b is a filter plate composed of a perforated plate 10 having a slightly coarse mesh and a mesh plate 10 'having a fine mesh on the front and rear surfaces of the core plate 9. The hollow plate body is attached with a thick rectangular frame-shaped gap holding frame 11 around the front and rear surfaces, and an injection hole 12 penetrating between the front and rear surfaces is provided at the upper end of the hollow plate body. Is provided with a suction hole 13 penetrating between the front and rear surfaces.

By using the wire net 10 as the filter plate, it is less likely to be clogged as compared with the filter cloth which has been conventionally exclusively used as a filter material for the dehydration plate, and is suitable for filtering sludge S containing fine particles of cement. It is suitable, and can be repeatedly used by washing after use, and is excellent in durability.

The core plate 9 is provided with an edge frame 14 having a small height at the peripheral portions of the front and rear surfaces thereof, and a stepped concave surface 15 inside the edge frame.
A large number of projections 16 are formed so as to have substantially the same height as the edge frame 14.

The projections 16 are formed on the perforated plate 10 and the mesh plate 10 '.
Is for partially supporting a filter plate such as the above and forming a suction space between the filter plate and the step concave surface 15, and a large number of projections 16 are arranged in series in the step concave surface 15 at a small interval. Are provided so as to intersect each other in a plurality of rows vertically and horizontally or diagonally, and the projections around the small space are arranged by arranging so as to form a plurality of rectangular or diamond-shaped small spaces surrounded by four intersecting projection rows. Air or water can be smoothly circulated in the entire suction space between the filter plate and the step concave surface 15 while stably supporting the filter plate by the rows.

The protrusion 16 may be formed integrally with the core plate 9 at the same time as the core plate 9 is formed. However, after the core plate 9 is formed, a wire mesh sheet of synthetic resin or the like is attached to the step concave surface 15 to form this mesh. The protrusions 16 can be formed by slightly raising the intersecting portions of the wire rods.

The injection hole 12 of the gap holding frame 11 is provided in a peripheral portion 11a in which a part of the upper end portion of the gap holding frame 11 is projected inward or outward in a semicircular shape, and the injection hole 12 is provided in the peripheral portion 11a. An introduction groove 17 is formed from the inner peripheral edge of 12 to the end edge facing the space inside the gap holding frame 11.

The suction holes 13 of the gap holding frame 11 are provided at the left and right corners of the lower end of the gap holding frame 11, and the suction holes 13 of the core plate 9 are provided.
Are provided at the left and right corners of the lower end of the stepped concave surface 15, so that the suction holes 13 are partially opened in the suction space between the filter plate 10 and the stepped concave surface 15 between the front and rear surfaces of the dehydration plate 5b. .

The injection hole 12 is formed by the stepped concave surface 15 of the core plate 9.
It is formed on a base plate portion such as a circle or a quadrangle having substantially the same height as the edge frame 14 projecting at the center of the injection hole 12, and the injection hole 12 is formed around the injection hole 12 at the center of the clearance holding frame 11. The formed annular peripheral portion is attached, and the introduction groove 17 is formed on the surface of the peripheral portion from the inner peripheral edge of the injection hole 12 to the peripheral edge facing the space inside the gap holding frame 11, and further the filter plates 10, 10 '. The injection hole 12 may be provided at the same position, and the peripheral portion thereof may be sandwiched between the circular base plate portion of the core plate 9 and the peripheral portion.

As described above, the intermediate dewatering plate 5b is provided with the edge frame 14, the step concave surface 15 and the protrusion 16 on both sides of the core plate 9, and the filter plate and the gap holding frame 11 are attached to both sides thereof, while the tip dewatering is performed. The plate 5a and the rear end dehydration plate 5c are, as shown in FIG.
The edge frame 14, the step concave surface 15 and the protrusion 16 are provided on one surface of the core plate 9 '.
This is different in that a filter plate composed of a perforated plate 10 and a mesh plate 10 'and a gap holding frame 11 are attached to one side of this, and an injection hole 12 and a suction hole 13 are provided in the tip dehydration plate 5a. Although it is provided at the same position as 5b, the injection hole 12 and the suction hole 13 do not have to be provided in the core plate 9'of the rear end dehydration plate 5c (even if provided, it can be sealed by the pressure plate 8). Good).

That is, in the case of the tip dehydration plate 5a, in order to press the front surface thereof onto the pedestal 3, the edge frame 14, the step concave surface 15 and the projection 16 are provided on the rear surface of the core plate 9 ', and the porous plate 1 is formed on this surface.
0 and a mesh plate 10 'and a filter plate and a gap holding frame 11 are attached, and in the case of the rear end dehydration plate 5c, the pressure plate 8 is pressure-bonded to the rear surface thereof, so that the edge frame is formed on the front surface of the core plate 9. 1
4, stepped concave surface 15 and projection 16 are provided, and the filter plate and the gap holding frame 11 are attached to this surface.

The dewatering plates 5a, 5b, 5c are connected in series by connecting plates adjacent to each other by a connecting line 18 such as a chain having a constant length.
By retracting the trailing edge dehydration plate 5c through the pressure plate 8 by the contraction operation of the adjacent dehydration plates 5c, as shown in FIG.
The a, 5b, and 5c are sequentially spaced apart by the length of the connecting cable 18.

A supply port 19 and a suction port 20 for sludge or the like are provided in a portion corresponding to the injection hole 12 and the suction hole 13 on the receiving table 3 to which the tip dehydration plate 5a is brought into pressure contact. The sludge S or the like S is pressure-fed through the supply pipe 21, and the suction port 20 is vacuum-sucked through the suction pipe 22 by a vacuum pump.

A convex portion having the same height as the edge frame 14 is provided at the center of the stepped concave surface 15 of the core plate 9, and the gap holding frame 11 is provided on the convex portion.
A spacer 23 having substantially the same height as the above is attached, and the porous plate 10 and the mesh plate 10 'are sandwiched between the core plate 9 and the bulging of the central portion of the porous plate 10 and the net plate 10'.

Next, a method of dewatering sludge S or the like by using the dewatering device configured as described above will be described.

First, the hydraulic cylinder 7 provided on the pressurizing table 2 is extended, and the dehydrating plates 5a, 5b and 5c are pressed by the pressurizing plate 8 attached to the rod end of the hydraulic cylinder 7, and the dehydrating plates 5a, 5b and 5c are pushed between the pressurizing plate 8 and the receiving table 3. Hold by crimping.

In this pressure-bonded state, the dehydration plates 5a, 5
Adjacent dewatering plates 5a and 5b, 5b and 5 are formed so that the gap holding frames 11 and 11 of b and 5c adjacent to each other are pressure-bonded in an airtight manner
A space filled with sludge S or the like surrounded by the gap holding frames 11, 11 is formed between the filter plates 10, 10 'of b, 5b and 5c, and the space is filled with the injection hole 12 through the introduction groove 17.
Is in communication with.

Next, the pressure feed pump is driven to feed sludge S or the like under pressure into the feed hole 19 through the feed pipe, and the sludge S is injected into the feed hole 12.
Then, the filling space is filled between the dehydration plates 5a, 5b, 5c through the introduction groove 17.

If a predetermined amount (small amount) of cement is added to sludge or the like in advance and the fine particles of soil are hardened to coarsen them, the dehydration efficiency can be further improved.

After the injection and filling are completed, the pressure feed pump is continuously driven to continue the pressure filling and suction.

Vacuum suction is performed by a vacuum pump through a suction pipe connected to the port 20, so that the stepped concave surface between the filter plate 10 and the core plates 9 and 9'in each dehydration plate 5a, 5b, 5c is sucked through the suction hole 13. The air in the suction space with 15 is vacuum-sucked, and the water content of the sludge S filled in the filling spaces between the dehydration plates 5a, 5b, 5c is filled by the filling pressure and the vacuum suction force. Suction and dehydration are performed while filtering the sediment through the.

On the other hand, since the sludge S is continuously pressure-filled during the dehydration, even if the volume of the sludge S is reduced by dehydration, the reduced amount of the sludge S is filled in the filling space. It is surely replenished inside, and the sludge S does not always fill the filling space in a compacted manner to form a cavity.

After the water content ratio of the sludge S etc. is lowered to the reference value or less in this way, the hydraulic cylinder 6 as shown in FIG.
By retracting, the rear end dehydration plate 5c is retracted via the pressurizing plate 7, and adjacent dehydration plates 5a, 5b, 5c are sequentially separated by the length of the connecting rope 18,
The dehydrator 5a, 5b, 5c is vibrated by a vibrator attached to the support rail 1 or the like to discharge the dehydrated earth and sand to a discharge tank or discharge chute below.

In the above embodiment, the dehydration plate 5a,
The case of dehydrating a relatively large amount of sludge and the like by configuring a plurality of filling spaces from 5b and 5c has been described. It suffices that one filling space is constituted by two dehydration plates, the front dehydration plate 5a and the rear dehydration plate 5c to which the filtration plates 10 and 10 'are attached.

[0044]

As described above, according to the present invention, sludge or the like is pumped during the dehydration process and vacuum-sucked while continuing the pressure-filled state. Therefore, the water in the sludge or the like is vacuum-sucked from the outside of the filling space. Due to the force and the filling pressure from the inside which acts at the same time, the water is strongly separated from the solid content and can be efficiently dehydrated, and the use of the solidifying agent can be greatly reduced or eliminated, which is economical. At the same time, since the sludge and the like are continuously filled under pressure, even if the volume of the sludge or the like decreases due to dehydration, the reduced amount of sludge or the like is surely replenished in the filling space, and the sludge or the like is always filled in the filling space. It is possible to prevent a reduction in dehydration efficiency due to the generation of voids without being filled with pressure to form voids.

In the case of dehydration only by pressure filling, as the solid content becomes harder with dehydration, the pressing force becomes less likely to be transmitted to the entire sludge and the like, but sufficient dehydration cannot be achieved. By using the vacuum suction force together with the filling pressure, it becomes possible to perform extremely effective dehydration by compensating for the drawbacks of pressure dehydration only.

Further, the water in the thin sludge or the like in the filling space between the dewatering plates is extremely removed by the filter plates which are in contact with the sludge or the like in the filling space by vacuum suction as a wide surface parallel to each other. It is possible to suck and dehydrate efficiently in a short time and uniformly as a whole.

By closely contacting the dewatering plates with each other, a filling space can be formed between them so that sludge or the like can be filled therein for dewatering. Also, after the dewatering is completed, the rear end dewatering plate has a contacting interval. The soil that has been dehydrated can be easily discharged by spreading it, and the dehydration can be repeatedly performed after discharging, which is efficient.

A large number of protrusions provided on the concave surface of the core plate in a stepped manner are arranged in series at small intervals, and a plurality of rows of these protrusions are provided so as to intersect each other vertically or horizontally or diagonally. A plurality of rectangular or diamond-shaped small spaces surrounded by four circumferences are formed, and the small space part supports the filter plate partially stably to form a suction space between this and the step concave surface. Air or water can be smoothly circulated in the entire space.

Further, an introduction groove is formed in the peripheral portion of the opening end of the injection hole from the inner peripheral edge of the opening end of the injection hole to the edge portion of the peripheral portion facing the space inside the gap holding frame. Therefore, the introduction hole can be rationally constructed by a simple means without the need for an independent and separate material constituting the introduction hole for the filling space between the dehydration plates.

[Brief description of drawings]

FIG. 1 is a side view of a dehydrator according to the present invention.

FIG. 2 is a plan view of the dehydrator of the present invention.

FIG. 3 is a front view of the dehydrator of the present invention.

FIG. 4 is a side view of the dehydrator of the present invention in a state where the dehydrating plates are separated from each other.

FIG. 5 is an exploded perspective view of an intermediate dehydration plate according to the present invention.

FIG. 6 is a front view of an intermediate dehydration plate according to the present invention.

7 is a cross-sectional view of the dehydration plate taken along the line AA in FIG.

[Explanation of symbols]

 1 base 2 pressurizing table 3 receiving table 4 guide rail 5a tip dehydration plate 5b middle dehydration plate 5c rear end dehydration plate 6 suspension 7 hydraulic cylinder 8 pressurizing plate 9 core plate 9'core plate 10 perforated plate (filter plate) 10 ' Net plate (filter plate) 11 Gap holding frame 11a Overhanging part 12 Injecting hole 13 Suction hole 14 Edge frame 15 Stepped concave surface 16 Protrusion 17 Introducing groove 18 Connecting cord 19 Supply port 20 Suction port 21 Supply pipe 22 Suction pipe 23 Spacer

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Fukashi Koguchi 7-7-1-506 Hikarigaoka, Nerima-ku, Tokyo (72) Inventor Akihiko Yasuda 37 Kitamachi, Shinjuku-ku, Tokyo Maeda Construction Kitamachi Dormitory (72) Inventor Minoru Tsuchiya 3-12-16 Niwanishi, Funabashi City, Chiba Prefecture (72) Inventor Kenzo Sugaya 2-24-10-806 Tamagawa, Ota-ku, Tokyo (72) Inventor Yuji Kawasaki 607-1 Sanjo-cho, Marugame City, Kagawa Prefecture

Claims (7)

[Claims] 1. A filling space surrounded by a filter plate and a frame body that surrounds the gap while holding a required gap, is filled with sludge under pressure, and while the pressure filling is continued, the outside of the filling space is filled. By vacuum suction through the filter plate from
A method for dehydrating sludge and the like, which comprises dehydrating the water content of the sludge and the like. 2. The method of dewatering sludge or the like according to claim 1, wherein a predetermined amount of cement is added to the sludge or the like in advance. 3. A plurality of dehydrating plates slidably supported on horizontal rails are stacked on top of each other and pressure-bonded in an airtight manner. A filling space surrounded by a gap holding frame is provided,
The filtration plate of each of the dehydration plates is supported at its back surface by an edge frame around the core plate and a protrusion provided on the inner side thereof with a stepped concave surface,
Each of the dehydration plates is provided with a series of injection holes for sludge or the like communicating with the filling space, and a series of suction holes for communicating with the filtration plate and the suction space having a stepped concave surface, and the injection holes are for feeding sludge or the like under pressure. A dewatering device for sludge or the like, which is communicated with a pipe, and the suction hole is communicated with a vacuum suction pipe. 4. The dewatering device for sludge or the like according to claim 3, wherein adjacent dewatering plates are connected by connecting lines. 5. An edge frame having a small height is provided on the peripheral portion of the surface,
A core plate in which a large number of protrusions having substantially the same height as the edge frame are provided on the stepped concave surface inside the edge frame, a filter plate closely attached to the periphery of the edge frame of the core plate, and the core. A gap holding frame formed in a frame shape along the periphery of the plate and closely attached to the edge frame of the core plate at the periphery. And a suction hole that penetrates the lower end of the stepped concave surface of the core plate and the gap holding frame in series, and the opening of the injection hole is formed around the opening end of the injection hole. A dehydration plate for sludge or the like, characterized in that an introduction groove is formed from an inner peripheral edge of the end to an edge portion of the peripheral portion facing a space inside the gap holding frame. 6. The sludge according to claim 5, wherein a large number of projections are arranged in series on the concave surface of the core plate at a small interval, and a plurality of rows of the projections are provided in a direction intersecting with each other. Dehydration board for etc. 7. The dehydration plate for sludge or the like according to claim 5, wherein the projection is an intersection of wire rods of a wire mesh netting sheet attached to the stepped concave surface of the core plate.