JP2001276898A - Treating equipment for dredged earth and sand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently classify and take out sand-components from the earth and sand dredged from bay coast, effluent rivers, etc., and to reduce the volume of the dredged earth and sand to be reclaimed in sedimentation basins and disposal plants. SOLUTION: The muddy water containing the dredged earth and sand is forcibly fed from a raw water introducing pipe 10 via a reduced pressure vessel 20 to a feed sump 30 and the raw water stored in the bottom of the feed sump 30 is supplied by feed pumps 30a and 30d to negative pressure liquid cyclones 50a to 50d. Granular materials of large grain sizes are separated from a slurry containing the granular materials of large grain sizes discharged from the lower parts of the respective liquid cyclones 50a to 50d are separated by an aqua- screen 70 and the desalting of the granular materials is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dredged soil treatment apparatus for efficiently classifying sand from dredged sand dredged from a bay shore or an outflow river.

[0002]

2. Description of the Related Art Conventionally, sediment deposited on a bay shore or a runoff river causes obstruction of a navigation channel and a decrease in river flow.
After being dredged by a dredger equipped with a dredge machine (also called a sweeping boat), it is thrown into a pre-set sedimentation basin, or subjected to solar drying or cement treatment to reduce the volume, and then temporarily piled up. And then landfilled at a disposal site.

[0003]

Since the accumulation of runoff sediment on the bay shore and runoff rivers occurs continuously, it is necessary to carry out dredging work almost regularly. It was not easy to secure a sedimentation basin for storing sediment and the landfill for reclaiming the sediment.
In addition, in the above-described treatment by solar drying, the effect of merely removing water is small, and the effect of reducing the volume is small. In the reduction in volume by the cement treatment, not only the processing equipment becomes large, but also the volume is sufficiently reduced due to mixing of cement. There was a problem that conversion was not possible. Therefore, there is a demand for the development of a technology for efficiently treating the large amount of dredged soil continuously generated to reduce the volume.

The present invention has been made in view of the conventional problems, and efficiently sorts and removes sand from sediment dredged from a bay shore or an outflow river, thereby burying the sediment in a sedimentation pond or a disposal site. The purpose is to reduce the volume of dredged soil.

[0005]

According to a first aspect of the present invention, there is provided an apparatus for treating dredged soil comprising a liquid cyclone, a liquid supply tank for supplying dredged sand to the liquid cyclone, and a liquid cyclone. The discharged muddy water containing the particulate matter having a predetermined particle size or less is returned to the liquid supply tank.

[0006] The apparatus for treating dredged earth and sand according to claim 2 comprises:
A negative pressure type hydrocyclone is used as a liquid cyclone, and a nozzle made of an elastic body is attached to a lower outlet of the negative pressure type hydrocyclone.

[0007] The apparatus for treating dredged earth and sand according to claim 3 comprises:
The liquid supply tank is provided with a seal tank communicating with the liquid supply tank at the upper part and the lower part thereof, and muddy water containing fine particles having a small particle diameter discharged from the upper part of the liquid cyclone is returned to the seal tank. Things.

[0008] The apparatus for treating dredged earth and sand according to claim 4 comprises:
Classification means is provided for classifying a slurry containing particulate matter having a large particle diameter discharged from a lower discharge port of the hydrocyclone, and the particulate matter having a large particle diameter is classified.

[0009] The apparatus for treating dredged soil according to claim 5 comprises:
As the classifying means, a floating classifier that conveys the slurry in the ascending direction of a belt conveyor having an ascending slope portion and adds water to the slurry at a predetermined position in the ascending slope portion is used.

[0010] The apparatus for treating dredged soil according to claim 6 comprises:
The washing water containing the granular material having a small particle diameter separated by the floating classifier is returned to the liquid supply tank.

[0011] The apparatus for treating dredged soil according to claim 7 comprises:
A means is provided for adding water to the slurry containing the particulate matter having a large particle diameter discharged from the lower discharge port of the hydrocyclone to remove salt from the particulate matter.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of a dredged soil processing apparatus according to the present embodiment. Numeral 10 denotes muddy water (hereinafter referred to as raw water) containing, for example, sediment deposited on a bay shore or an outflow river drawn by a dredge robot (not shown). )
Raw water introduction pipe for pumping the following to the liquid supply tank 30,
20 is a decompression tank for reducing the pressure of the raw water sent to the pump,
Reference numeral 30 denotes a liquid supply tank (hereinafter referred to as a feed sump) for temporarily storing the raw water decompressed in the decompression tank 20 and for supplying the raw water by feeding the raw water to negative pressure type liquid cyclones 50a to 50d by feed pumps 30a and 30b. ) And 40 are seal tanks communicating with the feed sump 30 at the upper and lower portions, 50a to 50d are negative-pressure liquid cyclones for classifying raw water supplied from the feed sump 30, and 60 is each of the liquid cyclones 50a to 50
The spigot tank 70 for temporarily storing the slurry containing the large-sized particles discharged from the lower part of 0d, and the 70 containing the slurry containing the large-particles sent from the spigot tank 60 is moved up the inclined belt conveyor. A floating classifier (hereinafter referred to as “aquascreen”) that conveys the sloping portion while adding water to the slurry at a predetermined position of the upslope is used to separate fine particles mixed in the slurry by the aquascreen 70. Classification process,
The above-described treatment for desalting large-sized particles in the slurry is performed simultaneously. 80 is the aqua screen 70
This is a bifurcated chute for distributing the granules having a large particle size classified by the above to two belt conveyors 90a and 90b. The granules are sent to a sand processing plant (not shown) by the belt conveyors 90a and 90b and stored or classified. .

FIG. 2 shows a decompression tank 20 and a feed sump 30.
FIG. 4 is a view showing details of the seal tank 40, and the feed sump 30, the pressure reducing tank 20, and the seal tank 40 are integrally connected via partition plates 30A and 30B, respectively. A steel capture net 21 of about 13φ is provided in the decompression tank 20 (omitted in FIG. 2; see FIG. 1).
The capture net 21 reduces the pressure of the raw water pumped from the raw water introduction pipe 10 and captures a large lump of contaminants such as garbage or the like having a size of several cm or more mixed in the raw water. I have to. Further, the partition plate 30A provided between the feed sump 30 and the decompression tank 20 completely separates the feed sump 30 and the decompression tank 20 at the bottom, but the height thereof is set at the upper end surface. And lower than the upper end surface of the decompression tank 20, whereby the raw water deenergized in the decompression tank 20 is separated from the partition plate 30 </ b> A.
It overflows from above and flows into the feed sump 30. The feed sump 30 is provided on the partition plate 30A.
Temporarily store the raw water overflowing from
Treated water containing particles having a relatively large particle size stored at the bottom is pumped to the negative-pressure liquid cyclones 50a and 50b and the negative-pressure liquid cyclones 50c and 50d by feed pumps 30a and 30b, respectively. In addition, an upper communication passage 30p that connects the feed sump 30 and the seal tank 40 is provided above the partition plate 30B provided between the feed sump 30 and the seal tank 40. The liquid overflows from the upper communication passage 30p and flows out to the seal tank 40. The seal tank 40 is provided with the feed sump 30.
Water from the plant and negative pressure type hydrocyclones 50a to 50d
A tank main body 41 for storing the treated water from the upper part of the tank and a drain passage 42 for draining the supernatant liquid into a reservoir (not shown). This drain passage 42 has a partition plate 4
0A is provided, and the supernatant liquid of the seal tank 40 flowing out from the upper part of the partition plate 40A is sent to the reservoir for reclaiming the dredged soil through the drainage passage 42. On the other hand, a lower communication passage 30q that connects the feed sump 30 and the seal tank 40 is provided below the partition plate 30B provided between the feed sump 30 and the seal tank 40, and flows into the seal tank 40. The particulate matter having a relatively large particle size contained in the treated water is returned to the bottom of the feed sump 30 through the lower communication passage 30q. In FIG. 2, the feed pump 30a,
Only the system of the negative pressure type hydrocyclones 50a and 50b is described.

FIG. 3 is a view showing the structure of a negative pressure type liquid cyclone 50 (50a to 50d) according to the present embodiment. In the figure, reference numeral 51 denotes a cylindrical member having a lower inner diameter gradually reduced. A cyclone body 52 is provided with a processing material introduction pipe 5 provided on a wall of the upper part 51 a side of the body 51.
Reference numeral 3 denotes a material discharge pipe provided at a distal end of a lower portion 51b of the main body 51, reference numeral 54 denotes a rubber spigot nozzle attached to the material discharge pipe 53, and reference numeral 55 denotes a substantially central part of an upper portion of the main body 51. Riser 56, this riser 5
A transfer pipe 57 for returning treated water containing particles having a small particle diameter discharged from the seal tank 40 to the seal tank 40 is provided on the ascending pipe 55 side of the transfer pipe 56 and introduces air into the transfer pipe 56 to perform the above-described operation. Exhaust pressure adjusting means 58 for adjusting the exhaust pressure of the negative-pressure liquid cyclone 50 is an introduction amount adjustment for adjusting the introduction amount of the processing material conveyed to the negative-pressure liquid cyclone 50 provided in the preceding stage of the processing material introduction pipe 52. It is a valve. The other end of the transfer pipe 56 is installed such that its opening is located in the treated water stored in the seal tank 40.

In the liquid cyclone, liquid containing various-sized particles is jetted at high speed onto the inner wall of a cylindrical main body having a discharge port at a lower end, and the liquid forms a vortex called a primary rotational flow. When moving downward along the inner wall of the cyclone body, the atmospheric pressure at the center of the cyclone body decreases, and the liquid rises from the inside of the primary rotation flow while the liquid forms a vortex called a secondary rotation flow Utilizing the phenomenon that the large particles contained in the liquid are moved downward while colliding with the inner wall of the main body and discharged from the lower outlet together with a part of the liquid, It is carried toward the upper part of the main body by the secondary rotating flow, and from the riser provided at the upper part in the cyclone main body,
The one end is discharged to the outside of the cyclone by a transfer pipe connected to the riser. In the present embodiment, a negative-pressure liquid cyclone 50 that generates a negative pressure inside the main body by using the other end of the transfer pipe in the treated water in the feed sump is used as the liquid cyclone. The negative pressure type liquid cyclone 50 introduces air into the transfer pipe 56 by means of a discharge pressure adjusting means 57 provided on the side of the rising pipe 55 of the transfer pipe 56 to reduce the negative pressure in the cyclone body 51 (the discharge pressure of the liquid cyclone). ) Is adjusted to control the particle size of the particles discharged from the upper part of the riser 55. In the present embodiment, in order to take out the sand content from the raw water of the introduced dredged soil, the particle diameter is about 7 mm.
The discharge pressure is adjusted so that particles having a size of less than 5 μm are discharged from the riser 55, and the discharged particles are returned to the seal tank 40. Negative pressure liquid cyclone 50
At the time of operation, it is attached to the material discharge pipe 53,
As shown in FIG. 3, the spigot nozzle 54 made of an elastic body is squeezed by the negative pressure generated inside the main body 51, so that the opening 54s of the spigot nozzle 54 is closed. Therefore, the solid content composed of particles having a large particle diameter which moves downward while colliding with the inner wall of the main body 51 by the primary rotating flow and is sent from the material discharge pipe 53 into the spigot nozzle 54 (mainly, the The sand is accumulated near the opening 54s. By the way, since the spigot nozzle 54 is made of an elastic body, when a solid content of a certain weight or more is accumulated, the opening 54 s of the spigot nozzle 54 is expanded by its own weight, and the solid content increases. The slurry is discharged from the opening 54s. Therefore, the slurry containing a large amount of solids composed of particles having a large particle diameter is discharged from the opening 54s of the spigot nozzle 54, instead of the conventional muddy water having a large water content. The discharged slurry is temporarily stored in a spigot tank 60 and then sent to an aquascreen 70 to remove sand.

By the way, the dredged soil injected into the negative pressure type hydrocyclone 50 is dredged together with seawater such as a bay shore or an outflow river or water having a large amount of seawater components, so that salt adheres to the surface of the earth and sand. I have. The salt attached to the surface of each granular material of the dredged soil is separated from the granular material due to the collision or friction between the granular materials due to the primary rotational flow generated in the hydrocyclone 50 and floats in the treated water.
Since the above-mentioned salt is non-adsorbent, the negative pressure type hydrocyclone 50
Even if the salt once detached adheres to the surface of the granular material, the salt can be sufficiently removed by simple washing with water such as passing the granular material through a shower. In addition, the sand content in the granular material is reduced by a negative pressure type hydrocyclone 50.
Since it is polished by internal collision or friction, high quality sand can be taken out.

FIG. 4 shows a floating classifier (aqua screen).
FIG. 3 is a schematic diagram showing one configuration of an aqua screen 70.
A drive roller 72a is provided with a belt 72 provided on a main frame 71 and provided with a flat portion 72H having a slight downward slope at one end and an upward slope 72K having an upward slope at the other end. And driven by the driven roller 72b from the flat portion 72H to the ascending portion 72K,
It is thrown from the spigot tank 60 into a predetermined position of the flat portion 72H of the belt 72,
The washing water is sprinkled on the slurry conveyed by the sprinkler 74 provided in the uphill section 72K, whereby sand of about 75 μm or more classified by the negative pressure type liquid cyclones 50a to 50d is separated. The sand content is classified from the slurry containing the main particles. That is, in the aqua screen 70, the slurry charged into the flat portion 72H of the belt 72 is conveyed in the direction of the ascending portion 72K, and the sprinkler 74 removes particles having a small particle size such as salt content in the washing water. And a drain port 7 of a drain channel 75 provided below the belt 72 together with the washing water.
5a and return to the feed sump 30,
Large particles having a large particle size mainly composed of sand conveyed to the upper side of the upward slope 72K are dehydrated, and are discharged from the discharge hopper 76 as shown in FIG.
Belt conveyor 90 via the bifurcated chute 80 shown in FIG.
a, 90b, and the belt conveyors 90a, 90b
To a sand treatment plant (not shown). Therefore, in the aqua screen 70, particles having a large particle size mainly of sand can be extracted, and the extracted particles can be desalted by the washing water from the sprinkler 74.

Next, a method for treating dredged earth and sand by the above apparatus
Will be described. In the present embodiment, for example,
From the dredging robot through the raw water introduction pipe 10
Is about 100 and the water content is 1000
Through 0, about 1100m^Three/ H flow rate and feeder
Is sent to the amplifier 30. The raw water is steel in the decompression tank 20
Is deenergized by the capture net 21 made of stainless steel and over the partition plate 30A.
It flows into the feed sump 30. Feedsa
Of relatively large particle size mainly due to the sand accumulated at the bottom of the pump 30
Mud water containing large particles is supplied to the feed pumps 30a, 30
b, 600m each^Three/ H (water; 550m^Three/
H, sand; 50m^Three/ H) by pressure, and a negative pressure liquid
Clone 50a, 50b and negative pressure type hydrocyclone 50
c, 50d. On the other hand, the feed sump 30
The supernatant liquid flows from the upper communication passage 30p to the seal tank 40.
leak. It should be noted that the above-mentioned capture net 21 is in a state where the apparatus is stopped.
Pull up with the front block 22, remove foreign matter, and clean
You. In the negative pressure type hydrocyclones 50a to 50d, the pressure
Mud containing fine particles of less than about 75 μm in the sent mud
, 275m each^Three/ H at a time from the riser 55
Return to the seal tank 40 via the pipe 56 and
Slurry containing solids mainly composed of sand of 5 μm or more
Nozzle 54 attached to a material discharge pipe 53
Is discharged from the opening 54s. The above slurry is about 100
m^Three/ H containing sand transported by
After being sent to link 60 and temporarily stored,
Into the box 70. It should be noted that the flow into the seal tank 40
Mud overflowing from the feed sump 30
Underwater and above the negative pressure type hydrocyclone 50a-50d
Granular material with a small particle size contained in the mud returned from the head
The supernatant of the seal tank 40 containing (silt) is drained.
From the water passage 42, about 1
000m ^Three/ H to the reservoir at a flow rate of
Granules having a relatively large particle size pass through the lower communication passage 30q.
Is returned to the bottom of the feed sump 30 again. Aku
In the ASCREEN 70, put in from the spigot tank 60
The slurried water is lifted while being watered by a sprinkler 74.
By transporting in the direction of the slope 72K, the dredged soil
The small particles in the inside are drained from the aqua screen 70
75a and return to the feed sump 30,
Grain mainly composed of sand conveyed to the upper part of the upward slope 72K
Large particles are discharged from the discharge hopper 76, and the belt
Conveyed to sand treatment plant (not shown) by conveyors 90a and 90b
I do. In this example, the belt conveyors 90a and 90b
The sand conveyed from each is about 50m^Three/ H
You. In the aqua screen 70, the sand content
Salt attached to the main particles with large particle size is sprayed
Removed by the wash water from 74.

As described above, of the dredged soil processed by the dredged soil processing apparatus according to the present embodiment, the removed sand is transported to the sand processing plant, and only the tilt is recovered in the reservoir or the disposal site. Can be The amount of sand extracted above is
Since it accounts for about 40% of the dredged earth and sand, the amount of dredged earth and sand buried in the reservoir or disposal site can be significantly reduced. The sand classified by the aqua screen 70 is originally of high quality if salt and the like are removed, and can be used as fine aggregate for concrete.

In the above-described embodiment, an example has been described in which the sand classification and the salt removal are simultaneously performed by the aqua screen 70. For example, the sand is classified from the slurry using a vibrating screen. After that, the classification process and the salt removal process may be performed by different means, for example, by passing the sand through a shower to remove the salt. Also, in the above example, the case where dredged soil from the dredging robot is treated has been described, but dredged from the bay shore or outflow river, etc., and dredged sediment separately deposited with an appropriate amount of water and used as raw water. In the same manner as in the above embodiment, sand can be efficiently extracted from the dredged soil and the volume of the dredged soil buried in the sedimentation basin or the disposal site can be reduced.

[0021]

As described above, according to the first aspect of the present invention, a liquid cyclone and a feed sump for supplying dredged soil to the liquid cyclone are provided, and a predetermined amount discharged from the liquid cyclone is provided. By returning the mud containing the granular material having a particle size equal to or less than the particle size to the feed sump, the sand is efficiently classified and taken out from the dredged sand dredged from the bay shore or outflow river, and the silt content in the dredged sand is removed. Since only the following fine particles can be buried in the sedimentation basin or disposal site, the volume of dredged soil to be buried can be significantly reduced.

According to the second aspect of the present invention, since a negative pressure type hydrocyclone is used as the hydrocyclone and a nozzle made of an elastic body is provided at the lower discharge port of the hydrocyclone, the sand content from the muddy water is reduced. Classification can be easily performed, and a slurry having a large solid content can be efficiently discharged with a simple structure.

According to the third aspect of the present invention, the feed sump is provided with a seal tank communicating with the feed sump at the upper part and the lower part thereof, and the supernatant of the feed sump is moved to the seal tank. The muddy water containing the granular material having a large size is pumped to the liquid cyclone, so that the classification efficiency can be further improved. In addition, since the muddy water discharged from the upper part of the hydrocyclone is returned to the seal tank, the granular material having a larger particle diameter discharged from the upper part of the liquid cyclone by being mixed with the small particle diameter is fed to a feed sump. And the particles are classified again by the hydrocyclone, so that the granular material having a large particle size can be surely classified.

According to the fourth aspect of the present invention, since there is provided a classifying means for classifying the slurry containing the granular material having a large particle diameter discharged from the lower discharge port of the hydrocyclone,
The sand content in the dredged soil can be reliably classified.

According to the fifth aspect of the present invention, as the classifying means, the slurry is conveyed in the ascending direction of a belt conveyor having an ascending portion, and is added to the slurry at a predetermined position of the ascending portion. Since the aqua screen is used, the sand in the dredged soil can be efficiently classified and the salt attached to the sand can be removed.

According to the sixth aspect of the present invention, the treatment liquid containing the granular material having a small particle diameter separated by the aquascreen is returned to the feed sump and classified again by the hydrocyclone. Can be reliably classified.

According to the seventh aspect of the present invention, since the slurry containing the particulate matter having a large particle diameter discharged from the lower discharge port of the hydrocyclone is added with water, the particulate matter is desalted. The granules can be made reusable.

[Brief description of the drawings]

FIG. 1 is a diagram showing a dredged soil processing apparatus according to the present embodiment.

FIG. 2 is a diagram showing details of a liquid supply tank according to the present embodiment.

FIG. 3 is a diagram showing details of a negative pressure cyclone according to the present embodiment.

FIG. 4 is a diagram showing details of a floating classifier according to the present embodiment.

[Description of Signs] 10 Raw water introduction pipe, 20 Decompression tank, 21 Capture net, 22
Chain block, 30 feed sump, 30a, 3
0b feed pump, 40 seal tank, 50a-
50d Negative pressure type hydrocyclone, 60 spigot tank, 70 aqua screen, 80 bifurcated chute, 9
0a, 90b Belt conveyor.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B04C 5/16 B04C 5/16 E02F 7/00 E02F 7/00 C (72) Inventor Hiroshi Ito Shinjuku, Tokyo 2-1 Tsukudo-cho, Ward Kumagaya-gumi Tokyo head office (72) Inventor Kenichi Abe 2-1 Tsukudo-cho, Shinjuku-ku, Tokyo Tokyo head office (72) Inventor Akira Yamazaki Tsukudo, Shinjuku-ku, Tokyo 2-1, Kumagaya-gumi Tokyo Main Office (72) Inventor Shuji Matsumura 2-1, Tsukudo-cho, Shinjuku-ku, Tokyo Tokyo, Japan (72) Inventor Kenji Kawaguchi 3 Nishishinjuku, Shinjuku-ku, Tokyo -7-1 Shinjuku Park Tower 12F Eco Plant Co., Ltd. (72) Inventor Yutaka Shinta 265 Sakurazawa, Yorii-cho, Osato-gun, Saitama F Over-time (reference) 4D053 AA03 AB04 BA01 BB02 BC01 CA01 CB13 CD25 DA10 4D059 AA09 BE39 CB27 CB30 CC04 EB07 4D071 AA13 AA53 AB02 AB23 AB25 CA01 CA05 DA20

Claims (7)

[Claims] 1. A liquid cyclone, comprising: a liquid supply tank that supplies dredged soil to the liquid cyclone;
A muddy water containing granular material having a predetermined particle size or less discharged from the liquid cyclone and returned to the liquid supply tank, wherein the dredged soil and sand is treated. 2. The dredged soil treatment according to claim 1, wherein the hydrocyclone is a negative pressure type hydrocyclone, and a nozzle made of an elastic body is attached to a lower outlet of the negative pressure type hydrocyclone. apparatus. 3. The liquid supply tank is provided with a seal tank communicating with the liquid supply tank at an upper portion and a lower portion thereof, and muddy water containing fine particles having a small particle diameter discharged from an upper portion of the liquid cyclone is supplied to the seal tank. 3. The dredged soil processing apparatus according to claim 1, wherein the dredged soil and sand are returned to the condition. 4. A classifying means for classifying a slurry containing a granular material having a large particle diameter discharged from a lower discharge port of the hydrocyclone.
The apparatus for treating dredged soil according to any one of claims 1 to 4. 5. The method according to claim 1, wherein the classifying means uses a floating classifier that conveys the slurry in an ascending direction of a belt conveyor having an ascending portion and adds water to the slurry at a predetermined position of the ascending portion. An apparatus for treating dredged soil according to claim 4, characterized in that: 6. The apparatus for treating dredged soil according to claim 5, wherein the washing water containing the granular material having a small particle diameter separated by the floating classifier is returned to the liquid supply tank. 7. The liquid cyclone according to claim 1, further comprising means for adding water to a slurry containing particles having a large particle diameter discharged from a lower outlet of the liquid cyclone to remove salts of the particles. Item 4. An apparatus for treating dredged soil according to any one of Items 3.