JPH09158245A - Method and device for treating dredged sludge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously and stably treate dredged sludge by adding a filler material to the sludge in a passage, filtering and draining the moisture in the sludge from the passage in a water separating part, then adding a solidifying material to the sludge and transporting the resulting sludge to a disposing place. SOLUTION: A dredged sludge is transported in a pipeline, a filler material is added thereto in a filler material adding and kneading part 10, and the resulting sludge is stirred by a stirring blade 12 while it is sent by a screw blade 11. The sludge is then carried to a water separating part, wherein the moisture is filtered and drained through the wall surface of a filter inner pipe 21 by a suction pump 23B. The sludge is sent to a sludge content measuring part 30 to measure the sludge content by a load detector 35. The flow rate of the sludge is measured by an electromagnetic flowmeter 40. Further, the sludge is carried to a solidifying material adding and kneading part 50, a proper quantity of a solidifying material 56 such as cement is added thereto on the basis of the sludge content and flow rate, and the resulting sludge is stirred by a stirring blade 52 while it is carried by a screw blade 51, and transmitted to a disposing place 60.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for treating dredged mud soil associated with dredging work in lakes and harbors.

[0002]

2. Description of the Related Art This type of dredged mud generally has a high water content, and it takes many years for the soil to develop sufficient strength as a ground even if it is dumped at a disposal site. Often requires some processing.

Therefore, conventionally, a method has been adopted in which mud from a dredger is put in a pit on the ground and treated in the pit.

[0004]

However, in the case of dredged mud, the treatment amount is often as large as several hundred m ³ per hour, and in the step of once putting it in the pit and treating it, the pit Not only is the transportation cost high, but the major obstacles are securing mechanical equipment and working yards near the pit.

In view of the above, a treatment method of a system in which a solidifying material is supplied to a sludge discharge pipe from a dredger and mixed in a pipeline has been proposed.

However, the dredged soil directly pumped from the dredging ship not only contains a large amount of water but also has a large water content ratio, which makes uniform solidification difficult.

Therefore, a main object of the present invention is to continuously and stably treat dredged soil having a high water content ratio and a large variation in water content ratio in a conveying pipeline.

[0008]

According to the invention as set forth in claim 1 which has solved the above-mentioned problems, a step of adding a hydrophobic material to the mud in the process of transporting the dredged mud generated in the flow path, It is characterized in that the water is transported to a disposal site through a step of filtering and draining water in the mud from the flow path in a water separation unit provided in the middle of the flow path, and a step of adding a solidifying material to the mud. It is a method of treating dredged mud.

It is possible to omit the addition of the hydrophobic material. Therefore, as described in claim 2, in the process of transporting the dredged mud generated in the flow path, the water separation part provided in the middle of the flow path. In order to pass through the step of filtering and draining the water in the mud from the flow path, the step of adding the solidifying material to the mud,
A treatment method of dredged mud characterized by transporting to a disposal site is also proposed.

It is also possible to omit the addition of the solidifying material only by adding the hydrophobic material, and therefore, as described in claim 3, in the process of transporting the dredged mud generated in the flow path,
Characterized in that it is transported to a disposal site through a step of adding a hydrophobic material to the mud, a step of filtering and draining water in the mud from the flow path in a water separation unit provided in the middle of the flow path, A method for treating dredged mud is proposed.

Further, in the invention described in claim 4, in the process of transporting the dredged mud generated in the flow path, a step of adding a hydrophobic material to the mud, water provided in the middle of the flow path In the separation part, the process of filtering and draining the water in the mud from the flow path, the process of measuring the mud content and the flow rate of the mud, and selecting the necessary solidifying material based on the measured mud content and the flow rate The method for treating dredged mud is characterized in that it is transported to a disposal site through a step of adding a solidifying material in order.

The hydrophobic material and the solidifying material can be added while stirring the mud.

On the other hand, the apparatus for treating dredged mud according to claim 6 is an apparatus for separating water in the mud during the process of transporting the dredged mud generated in the channel, and a wall surface in the middle of the channel. The part is a filter that blocks soil particles and permeates moisture, and a partition wall is provided around the outer periphery of this filter part, and a negative pressure is applied to the inside of the partition wall to forcibly externalize it. It is characterized in that it is provided with a drainage means for draining.

Further, as described in claim 7, a means for adding a hydrophobic material to the mud in a channel for conveying the generated dredged mud, and a mud in the water separating section provided in the middle of the channel. Which has a means for filtering and draining the water from the flow path, a means for measuring the mud content, a means for adding a solidifying material to the mud, in order, and the means for measuring the mud content are provided at both ends of the measuring pipe section. A flexible joint that is connected to the adjacent flow path, a fulcrum that supports one end of the measuring conduit, and a load detector that detects the load acting on the other end of the measuring conduit. An apparatus for treating dredged mud is also provided.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of the entire processing equipment according to the present invention, and FIGS. 2 to 6 are detailed views of respective parts thereof.

The dredged mud generated from the dredging ship 1 is transported to a disposal site such as above ground through a pipeline 2 forming a flow path. In the illustrated equipment, the hydrophobic material-added kneading section 10,
A water separation unit 20, a mud content measurement unit 30, an electromagnetic flow meter 40, and a solidifying material addition kneading unit 50 are provided in order.

These elements can be partially omitted depending on the properties of the mud to be treated and the conditions of the quality of the treated soil required at the site of use. These elements will be described in order.

(1) Addition of Hydrophobic Material (See FIG. 2) A kneading section 10 for adding a hydrophobic material is provided to the pipeline 2. Various types of hydrophobic materials have been developed for promoting the separation of soil particles and water in muddy water. However, since these hydrophobic materials require a reaction time until water separation occurs, after adding the hydrophobic material in the process of flowing in the pipeline 2, the hydrophobic materials are separated by a predetermined distance (for example, 1 to 2 km). It leads to the separation part 20. This causes a reaction of the hydrophobic material in those sections. This distance can be set from the flow velocity of the mud and the reaction time of the hydrophobic material with respect to the mud. If this distance cannot be secured, the required reaction time can be secured by increasing the inner diameter of the pipeline 2 and decreasing the flow rate.

In the adding and kneading section 10 of the hydrophobic material, as shown in FIG.
As shown in FIG. 1, the screw blade 11 and the stirring blade 12 are rotated around the central axis by the rotation motor 13 in the curved portion, and the swivel 14 is used.
The hydrophobic material 16 is supplied into the rotary shaft 15, and the hydrophobic material 16 is added to the flowing mud through the injection holes 15a at appropriate positions of the rotary shaft 15. The mud is fed by the screw blades 11 and, after receiving the addition of the hydrophobic material 16, is stirred by the stirring blades 12 to be uniformly kneaded and transported forward. Screw blade 1
No. 1 has a function of promoting kneading and also of promoting a pressure-feeding pressure.

(2) Water Separation Section (Filtration / Drainage Section) (See FIG. 3) The water separation section 20 has a double structure as shown in the drawing.
The inner tube 21 is, for example, a woven fabric hose filter that blocks soil particles and allows water to pass through.
1. A partition wall portion 22 such as a steel pipe is provided so as to surround the outer periphery of 1, and a negative pressure is applied to the partition wall portion 22 to forcibly drain water to the outside. The drainage means 23 including 23B is provided.

When suction is performed by the drainage means 23, a large pressure difference is generated between the pumping pressure of the mud and the suction pressure of the drainage, whereby the water in the mud is filtered and drained through the wall surface of the filter inner tube 21.

In this case, not only the filter is passed through, but a clearance is secured between the partition wall portion 22 and the filter inner tube 21 so that a certain amount of back pressure is generated around the filter inner tube 21 so that the amount of drainage is increased. By adjusting the drainage flow rate adjusting valve 23A or adjusting the number of revolutions of the suction pump 23B, it is possible to gently perform the filtering and draining and prevent the woven fabric forming the filter inner tube 21 from being clogged.

If necessary, by selecting the diameter of the inner pipe 21 of the filter, it is possible to prevent the inner pipe 21 from pulsating due to the mud pressure and prevent clogging. The length of the filter inner tube 21 is set depending on the property of the treated soil and the condition of the soil after dehydration.

Depending on such conditions, there is a case where the treatment can be carried out only by the filtered waste water without adding the hydrophobic material.

(3) Sludge content measuring unit (see FIG. 4) In the case of solidification treatment, since the water content ratio of mud is related to the amount of solidification material added, in order to obtain mixed soil of a certain quality. , The water content is kept constant before adding the solidifying material,
Alternatively, it is desirable to measure and control the addition amount of the solidifying material.

Therefore, it is important to understand the mud content as information for adjusting the amount of drainage of the water separation section 20 and setting the amount of solidifying material added. Here, the water content ratio is expressed as the ratio of the water of mud to the soil particles, and the water content ratio is expressed as the ratio of the soil particles to the entire mud water. Generally, when the soil is mainly treated, the water content ratio and the dredging water When mainly handling muddy water, it is expressed as a mud content.

The mud content measuring means 30 in the embodiment includes flexible joints 32A and 32B connected to adjacent flow paths provided at both ends of the measuring pipe line portion 31, and one end of the measuring pipe line portion 31. The fulcrum 33 to support and the load detector 35, such as a load cell, which detects the load which acts on the other end of the measuring pipe line part 34 are provided.

When the mud flows through the measuring pipe line portion 31, a moment acts on the fulcrum 33, and the moment can be measured by the load detector 35. Since this moment is proportional to the mud content of mud, the mud content can be measured based on the load. In this case, the buoyancy acting on the measuring conduit 34,
The flow rate is considered as a correction term.

(4) Electromagnetic flowmeter (see FIG. 4) As the electromagnetic flowmeter 40, a commercially available one can be applied as it is. The flow rate can be measured sufficiently even if the target mud has a high concentration. The electromagnetic flowmeter 40 can be effectively used for management of the amount of solidifying agent added, management of the daily treatment amount, and the like by using it together with the sludge content measuring means and the measured value.

(5) Solidifying material-adding and kneading section (see FIG. 5) In most cases, it is difficult to obtain high-quality soil simply by dewatering a large amount of fine grains. Therefore, it is desirable to knead and solidify the solidifying material to produce good quality soil. For the solidification treatment, a method of performing the mixing treatment at the disposal site 60 on the ground and a method of performing the mixing treatment at the plant are conceivable, but the equipment is simplified by performing the mixing treatment in the transportation process by the pipeline 2 as much as possible. It is preferable because it is possible.

Therefore, in the embodiment, similarly to the hydrophobic material-added kneading section 10, as shown in the drawing, the screw blade 51 and the stirring blade 52 are rotated around the central axis by the rotation motor 53 in the curved portion. None, the hydrophobic material 56 is supplied into the rotary shaft 55 through the swivel 54, and the injection hole 55a at an appropriate position of the rotary shaft 55
Solidifying material 56 such as cement and lime for flowing mud
Is to be added. Mud is screw blade 5
After receiving the addition of the solidifying material 56 while being sent by 1,
Stirring is carried out by the stirring blades 52, whereby the kneading is carried out uniformly and the kneading is carried to the disposal site 60. Screw blade 5
No. 1 has the function of making kneading effective and promoting the pressure feeding pressure to the disposal site.

(Others) In the above example, when mud having a small variation in mud content (water content) is supplied in a fixed amount, the mud content meter and the electromagnetic flow meter can be omitted, and the characteristics of the mud can be eliminated. Depending on the case, it may be sufficient to omit the addition of the solidifying material and only add and knead the hydrophobic material. The above operation load situation is managed under the control of a computer, and operation management and construction records are stored in a database and used for subsequent management.

On the other hand, the specific configuration of each of the above elements can be changed as appropriate.

[0034]

As described above, according to the present invention, advantages such as continuous and stable treatment of dredged soil having a high water content ratio and a large variation in water content ratio in the transfer pipeline are brought about. .

[Brief description of the drawings]

FIG. 1 is a schematic diagram of the entire processing equipment of the present invention.

FIG. 2 is a detailed view of a kneading section with a hydrophobic material added.

FIG. 3 is a detailed view of a water separation unit.

FIG. 4 is a detailed view of a sludge content measuring unit.

FIG. 5 is an enlarged view of an electromagnetic flow meter.

FIG. 6 is a detailed view of a solidifying material-adding and kneading section.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Dredger, 2 ... Pipeline, 10 ... Hydrophobic material addition kneading part, 20 ... Water separation part, 30 ... Mud content measuring part, 40 ... Electromagnetic flow meter, 50 ... Solidifying material addition kneading part.

Claims (7)

[Claims] 1. A step of adding a hydrophobic material to the mud in the process of transporting the dredged mud generated in the flow path, wherein water in the mud is flowed in a water separation section provided in the middle of the flow path. A method for treating dredged mud, which comprises sequentially carrying out a step of filtering and draining from a channel and a step of adding a solidifying material to the mud, and then transporting it to a disposal site. 2. A step of filtering and draining water in the mud from a flow channel in a water separation section provided in the flow channel in the process of transporting the dredged mud generated in the flow channel, and solidifying the mud. A method for treating dredged mud, which comprises sequentially carrying out the steps of adding materials and then transporting it to a disposal site. 3. In the process of transporting the dredged mud generated in the flow path, a step of adding a hydrophobic material to the mud, and a water separation unit provided in the middle of the flow path to flow the water in the mud. A method for treating dredged mud, which comprises sequentially carrying out a process of filtering and draining from a channel and then transporting it to a disposal site. 4. A step of adding a hydrophobic material to the mud in the process of transporting the dredged mud generated in the flow path, and a step of flowing water in the mud in a water separation unit provided in the middle of the flow path. The process of filtering and draining from the channel, the process of measuring the mud content and the flow rate of the mud, and the step of selecting the necessary solidifying material based on the measured mud content and the flow rate and adding the solidifying material to the mud After that, the method of treating dredged mud is characterized by transporting it to a disposal site. 5. The method for treating dredged mud according to claim 1, wherein the hydrophobic material and the solidifying material are added while stirring the mud. 6. A device for separating water in the mud during the process of transporting the dredged mud generated in the flow path, the filter being a wall part in the middle of the flow path for blocking soil particles and allowing water to pass therethrough. In addition, a partition wall portion is provided so as to surround the outer periphery of the filter portion, and a drainage means for forcibly discharging the drainage by applying a negative pressure to the inside of the partition wall portion is provided. A device for processing dredged mud. 7. A means for adding a hydrophobic material to the mud in a flow path for transporting the generated dredged mud, water in the mud being filtered and discharged from the flow path in a water separation section provided in the middle of the flow path. Means for measuring the mud content, means for adding the solidifying material to the mud in order, and the mud content measuring means are adjacent flow paths provided at both ends of the metering pipe section. A flexible joint that connects with
A treatment device for dredged mud, comprising: a fulcrum that supports one end of the metering conduit, and a load detector that detects a load acting on the other end of the metering conduit.