JPH0512003B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dewatering device for dewatering dredged mud in, for example, ports, rivers, swamps, etc.

[Conventional technology] In recent years, during dredging work for rivers, swamps, etc., when dredged mud is dumped onto land or reclaimed land, the dredged mud contains water, so if it is directly dumped, it will dry out in the sun. It may take a considerable number of days to
In addition, if a vehicle such as a dump truck is used to reach the dumping site, a considerable amount of water that is not originally needed is transported, which not only results in waste, but also causes problems such as mud being thrown out during transportation. May cause secondary pollution.

Therefore, in recent years, dredged mud has been dewatered using a dewatering device before being dumped or transported.

[Problem to be solved by the invention] Conventional dewatering equipment of this type employs a mud compression method, a vacuum adsorption method, and a specific gravity separation method, but these methods require the addition of polymer flocculants, etc. Not only does running cost become high because of the need for additives, but depending on the type of additive, it may become industrial waste for which there are limited places to dispose of it.

In addition, we can compress mud, use vacuum,
Methods that utilize differences in specific gravity have the disadvantage that there are limits to the dewatering performance of muddy soil, making it difficult to achieve highly efficient dewatering.

An object of the present invention is to provide a dehydration device that can highly efficiently dewater water in mud without adding a polymer flocculant or the like.

[Means for Solving the Problems] An example of means for achieving the object of the present invention is as follows:
It has a mud supply opening through which mud is supplied from the mud supply means and a treated mud discharge opening through which dehydrated mud is discharged. A sealable horizontal pressure tank in which a filtrate storage tank is formed, a mud intake valve that closes the mud supply opening during dewatering processing and opens the mud supply opening when mud is supplied, and the mud discharge opening during dewatering processing. A mud discharge valve is arranged along the axial direction in the pressure tank, and compressed air is ejected from a number of nozzles through the shaft, and the mud discharge opening is opened when discharging the treated mud. A screw shaft that stirs the mud in the pressure tank by forward and reverse rotation during processing, and transports the dehydrated mud toward the treated mud discharge opening by rotating in one direction when the dewatering process is completed, and a filtrate formed in the pressure tank. It has a filtrate valve for discharging the filtrate in the storage tank outside the tank, and during dehydration processing, the pressure tank is kept in a sealed state and compressed air is supplied into the screw shaft, and by pressurizing the compressed air. The dewatering device is characterized in that water in mud is discharged into the filtrate storage tank through the filter cloth material.

[Function] The dewatering device configured as described above is sealed when a certain amount of mud is stored in the pressurized tank, and while the mud is evenly stirred by the forward and reverse rotation of the screw shaft, the dewatering device is heated by the compressed air supplied from the screw shaft. , the mud is dehydrated under pressure, the water in the mud is discharged into the filtrate storage tank through the filter cloth material, and then the filtrate valve is opened to drain the fluid out of the pressurized tank.

Further, the dewatered mud is transferred toward the mud discharge opening by rotating the screw shaft in one direction after the dewatering treatment, and is discharged outside the pressurized tank.

[Example] The present invention will be described in detail below based on an example shown in the drawings.

Embodiment 1 FIG. 1 is a partially cutaway side view of Embodiment 1 of the dewatering device according to the present invention, FIG. 2 is a sectional view taken along line A-A, FIG. Figure 4 is a diagram showing the distribution of water in mud.

1 is a hopper with an open top, and a screen (not shown) formed in a lattice pattern is attached to the top opening surface of the hopper, which is used to collect mud excavated by a civil engineering machine such as a backhoe (hereinafter undehydrated mud is referred to as source mud). ) is injected through the screen. The screen removes bulky dirt from the source mud that is introduced into the hopper 1, and the screen is vibrated via an exciter (not shown) to remove large chunks of dirt that are caught on the grid. The mud is crushed into a size suitable for dehydration later on and then dropped. 2
is a horizontally elongated cylindrical tank with both ends closed, and a porous casing (to be described later) for passing moisture is attached to a lower tank portion 4' having a substantially semicircular cross section, and is attached to the outer periphery of this lower tank portion 4'. The filtrate is stored in the filtrate receiving tank 3. The filtrate receiving tank 3 is connected to the upper tank section 4 via the joint member 5, and by driving the filtrate tank opening/closing cylinder 21, the filtrate receiving tank 3 can be opened and closed relative to the upper tank section 4 as shown in FIG. It is designed to be locked in the closed position by a joint pin 6.

The other end of the upper tank section 4 extends to an extension of the filtrate receiving tank 3, and a mud discharge pipe 16 for discharging dehydrated mud is attached to the lower part of the other end.
Mud discharge valve 1 by air or hydraulic cylinder 16b
Mud is discharged from the mud discharge pipe 16 by opening 6a.

In addition, the upper tank part 4 has a level sensor 2 at the top that detects the level of mud contained in the tank 2.
2. An atmosphere release pipe 17 having an atmosphere release valve 17a that opens and closes under drive control of an air or hydraulic cylinder 17b.
is provided.

The lower tank part 4' has a porous casing 9 on its inner peripheral surface.
A filter cloth 10 is attached to the outer peripheral surface of the porous casing 9, and the filter cloth 10 is removably fixed to the porous casing 9 via a porous filter cloth cover 11.

In addition, the filtrate receiving tank 3 has a filtrate discharge pipe 18 attached to the lower part of one end, and the filtrate accumulated inside the filtrate receiving tank 3 is discharged to the outside of the tank through the filtrate discharge pipe 18. The filtrate discharge pipe 18 is opened and closed by opening and closing the filtrate discharge valve 18a by driving the hydraulic cylinder 18b. In addition, a filter cloth cleaning pipe 19 is attached to one end wall of the filtrate receiving tank 3 between the inner circumferential surface and the porous filter cloth cover 11, and a filter cloth cleaning valve 19a is controlled to open and close by an air or hydraulic cylinder 19b. By opening it, cleaning air is supplied into the tank 2 through the filter cloth cleaning pipe 19 and the filter cloth 10 is cleaned.

Further, the lower part of the hopper 1 is attached to the upper part of one longitudinal end of the tank 2 via a mud intake valve 15, and by opening this mud intake valve 15 via air or a hydraulic cylinder 15a, the inside of the hopper 1 can be opened. The source mud is supplied by falling.

Inside this tank 2, a hollow screw shaft 12, which also serves to stir and transport the source mud and supply compressed air for dewatering, is provided so as to be rotatable along the length direction.
One through end is connected to the rotary seal 13, and the other through end is fixed with a screw shaft chain wheel 8 connected to the screw shaft drive motor 7 via a chain 8a.
It rotates due to the driving force of. Note that the shaft may be rotated by a hydraulic motor or the like.

The screw shaft 12 has a hollow portion extending to the connecting end with the rotary seal 13 (the other end is closed), and a number of air nozzles 12b communicating with the hollow portion are formed on the peripheral wall 12a. When the pressure valve 20 is opened, compressed air from a compressed air source (not shown) is ejected into the tank 2 from the air nozzle 12b through the rotary seal 13 and the hollow portion. Further, screw blades 14 are formed in a spiral shape on the outer periphery of the screw shaft 12.
According to the rotation of the tank 2, the mud in the tank 2 is transferred from one end to the other end while being stirred.

The structure of the first embodiment has been described above, and its operation will be explained below.

When supplying the source mud in the hopper 1 into the tank 2, the intake valve 15, the atmosphere release valve 17a, and the filtrate discharge valve 18a are kept open, and the other valves are kept closed. The screw shaft 12 is always driven to rotate, and is appropriately rotated clockwise and counterclockwise during the dewatering process to prevent mud from accumulating in a part of the tank 2. At the end of the dewatering process, the mud is discharged. It rotates to transfer mud toward the pipe 16.

When the level sensor 22 detects that the tank 2 is full of mud, the intake valve 15,
The atmosphere release valve 17a is closed to seal the inside of the tank 2, and the pressurizing valve 20 is opened to supply compressed air into the tank 2 from the air nozzle 12a of the rotating screw shaft 12. As shown in Fig. 4, the source mud stored in the tank 2 includes surface adhesion water, crack capillary bound water, wedge-shaped capillary bound water, interstitial water, and free water around the solid mud. There is also internal water inside. When compressed air is pressurized into the tank 2 from the air nozzle 12a of the screw shaft 12, the air passes through the source mud in the order of the porous casing 9 → filter cloth 10 → porous filter cloth cover, as shown in FIG. As the compressed air passes through, water in the source mud passes through the filter cloth 10 and becomes a mist of filtrate, which accumulates in the filtrate receiving tank 3. that time,
As shown in Figure 3, the compressed air penetrates between the solids and even the internal water within the solids is removed, and the source mud is thoroughly stirred by the screw shaft, so it is uniformly mixed. It will be dehydrated.

The time for supplying compressed air into the tank 2, that is, the dewatering time, is set by a timer (not shown) according to the target moisture content based on the amount of source mud contained, the moisture content of the source mud, the compressed air pressure, etc. When the compression time is reached, the pressurizing valve 20 is opened to stop supplying pressurized air into the tank 2, and the atmosphere release valve 17a is opened to release the inside of the tank 2 to the atmosphere. The opening time of the atmosphere release valve 17a is controlled by an atmosphere release valve open timer, and the discharge valve 16 is closed when the atmosphere release valve open timer times up.
Open the valve a and discharge the dehydrated treated mud in the tank 2 to the outside of the tank.

Simultaneously with the opening of the discharge valve 16a, the filtrate discharge valve 18
Close the valve a, open the filter cloth cleaning valve 19a, and clean the porous casing 9, filter cloth 10, and porous filter cloth cover 11 with air. The opening time of the discharge valve 16a is controlled by a discharge valve timer, and when the discharge valve timer times up, the discharge valve 16a, the filter cloth cleaning valve 19a, and the atmosphere release valve 17a are closed, and the intake valve 15 and the filtrate discharge valve 18a are opened. Then, the source mud is taken into tank 2 again.

In the first embodiment, one tank 2 is attached to one hopper 1, but if two or more tanks 2 are attached and dehydration is performed continuously, the dehydration can be further improved. Processing power is improved.

Example 2 FIG. 5 is a schematic cross-sectional view of the second embodiment.

In this embodiment, two lower openings are formed in the hopper 1, and two tanks 33, both having the same structure, are arranged vertically through intake valves 31 and 32 provided in each opening.
34, respectively.

The tanks 33 and 34 have a cylindrical porous casing 35 inside a tank side plate (not shown) that is open at the bottom.
A filter cloth 36 is attached to the outer peripheral surface of the porous casing 35, and this filter cloth 36 is attached to the porous casing 35 from the outside with a porous filter cloth cover 37.
It has a structure that is removably fixed to the bottom end, and discharge valves 38 and 39 for discharging dehydrated mud are attached to the lower end, and air pressure pipes 41 and 42 in which a number of air nozzles 40 are formed in the center of the interior are installed in the vertical direction. Compressed air from a compressed air source (not shown) is supplied into the tank by opening pressurizing valves 43 and 44, respectively.

On the other hand, the lower ends of the tank side plates of the tanks 33 and 34 are located above the lower end of the porous casing 35, and a filtrate tray 45 for receiving the filtrate is provided at the lower end.
The filtrate in the filtrate dish 45 is discharged through a filtrate pipe (not shown).

43' and 44' are atmospheric release valves provided in the tanks 33 and 34, respectively.

The opening and closing of each valve is controlled by an air cylinder or the like.

The structure of this embodiment has been described above, and its operation will be explained below.

The dewatering device of this embodiment performs dewatering by alternately supplying the source mud in the hopper 1 to the tanks 33 and 34. For example, the intake valve 31 is opened and the source mud is introduced into the tank 33. In this case, the intake valve 32 is closed and the pressurizing valve 44 is opened to supply compressed air into the tank 34 to dewater the stored source mud. In the dewatering process, as in the previous embodiment, when compressed air passes through the source mud and passes through the porous casing 35 → filter cloth 36 → porous filter cloth cover 37, water is dehydrated as a mist of filtrate, which accumulates in the filtrate tray 45. When the dehydration process of the tank 34 is completed, the pressurizing valve 44 is closed, the atmosphere release valve 44' is opened, and the discharge valve 39 is opened.
The valve is opened to allow the treated mud in the tank 34 to fall and discharge under its own weight, and the intake valve 31 is closed to stop supplying the source mud to the tank 33, and the source mud supplied to the tank 33 is dehydrated. Make it ready to start.
When the discharge of the treated mud in the tank 34 is completed, the discharge valve 39 and the intake valve 32 are opened to supply the source mud into the tank 34, and the atmosphere release valve 43' is closed and the pressurizing valve 43 is opened. Then, dewatering of the source mud in the tank 33 is started.

By repeating this operation, substantially continuous dehydration processing can be performed.

This embodiment configured for this purpose is similar to the embodiment 1 described above.
In addition to being able to carry out high-rate dehydration treatment in the same manner as in Example 1, there is also the effect of simplifying the structure since there are no rotating parts as in Example 1.

In addition, in this embodiment, since the dewatered mud is allowed to fall from the tank by its own weight, if the internal shape of the tank (the internal shape of the porous casing 35) is a truncated cone shape that widens at the bottom, the treated mud will fall. Improves self-weight falling properties.

Also, although two tanks are used for alternate operation, it is also possible to use only one tank as in Example 1.
Moreover, three or more units may be provided and operated continuously.

[Effects of the Invention] As explained above, the present invention is a batch-type dewatering device that dewaters a certain amount of mud stored in a pressurized tank using compressed air, and dewaters the mud while stirring the mud. As a result, uniform dehydration can be performed and efficient dehydration processing can be achieved.

Further, since the screw shaft has the functions of supplying compressed air, stirring the mud, and transporting the dehydrated mud, it also has the effect of simplifying the structure inside the pressurized tank.

Furthermore, since compressed air for dewatering is ejected from the screw shaft, which has a mud stirring function, dewatering can be performed while the treated mud is pressed against the filter material, improving dewatering efficiency. do.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view showing Embodiment 1 of the dewatering device according to the present invention, FIG. FIG. 4 is a diagram illustrating the behavior of water in mud, and FIG. 5 is a schematic sectional view of the dewatering device of Example 2. 1... Hopper, 2, 33, 34... Tank,
3...Lower tank part, 4...Upper tank part, 5...Joint member, 6...Joint pin, 7...Screw shaft drive motor, 8...Screw shaft chain wheel, 9, 35...Porous casing, 1
0,36...Filter cloth, 11,37...Porous filter cloth cover, 12...Screw shaft air nozzle, 13...
...Rotary seal, 14...Screw blade,
15, 31, 32...Intake valve, 16...Discharge pipe, 17...Atmospheric release pipe, 18...Filtrate discharge pipe,
19... Filter cloth cleaning pipe, 20, 43, 44... Pressure valve, 21... Filtrate tank opening/closing cylinder.

Claims (1)

[Scope of Claims] 1. It has a mud supply opening through which mud is supplied from the mud supply means and a treated mud discharge opening through which dehydrated mud is discharged, and a filter cloth material is attached to the lower part of the body as a partition wall. a sealable horizontal pressure tank with a filtrate storage tank formed between it and an outer plate; a mud intake valve that closes the mud supply opening during dewatering processing and opens the mud supply opening when mud is supplied;
A mud discharge valve that closes the mud discharge opening during dewatering processing and opens the mud discharge opening when discharging the treated mud; A screw shaft that ejects from a nozzle, agitates the mud in the pressure tank by forward and reverse rotation during dewatering processing, and transfers the dehydrated mud toward a treated mud discharge opening by rotating in one direction when dewatering processing is completed; It has a filtrate valve for discharging the filtrate in the filtrate storage tank formed in the pressure tank to the outside of the tank, and during dehydration processing, the pressure tank is kept in a sealed state and compressed air is supplied into the screw shaft. A dewatering device characterized in that water in the mud is discharged into the filtrate storage tank through the filter cloth material by pressurizing compressed air. 2. The dewatering device according to claim 1, wherein substantially the lower half of the body of the pressurized tank is configured to be openable and closable. 3 A vertical cylindrical filter having a mud supply opening in the upper part for supplying mud from the mud supply means, a mud discharge opening for discharging treated mud in the lower part, and having a filter cloth material on the circumference. A pressure tank, a mud intake valve that opens the mud supply opening during mud supply and closes it during dewatering, a mud discharge valve that opens the mud discharge port when mud is discharged and closes it during dewatering, and compressed air during dewatering. The pressurized air pipe is disposed in the pressurized tank through which water is ejected from a number of nozzles through the pipe, and the filtrate receiving means receives the filtrate that has passed through the filter cloth material of the tank. A dewatering device characterized in that water released from the filter is drained into a filtrate receiving means through the filter cloth material.