JP3375929B2 - Dredged soil treatment method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technical field relating to the treatment of dredged soil such as sludge and earth and sand dredged from the sea floor or rivers, which is mixed with a solidifying material and supplied to a landfill site or underwater pouring. Belong to

[0002]

2. Description of the Related Art Conventionally, in landfill, sludge and earth and sand deposited on the seabed and rivers have been effectively used as landfill material, and a method of treating with a solidifying material such as cement is known. As disclosed in Japanese Patent Laid-Open No. 5-98663, the water content of dredged soil dredged from the seabed is measured, and the dredged soil and cement are directly supplied and continuously discharged while stirring with a stirrer, and pumped. A method of treating the dredged soil supplied from the equipment to the landfill has been proposed. By the way, the treatment of sludge and dredged soil has not been required to make the treated soil uniform, although the lower limit is required for specific gravity and strength from the viewpoint of cost, but in recent years, Due to problems etc., it is desired that the landfilled soil is also a homogeneous treated soil. In addition, although it is not the treatment of dredged soil, in the treatment of construction sludge, the method for treating construction sludge, which detects the stirring load between the input sludge and the input solidifying material in the mixing device and controls the input amount of the solidifying material, is Patent No. 2881374. It is proposed as a publication.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention Japanese Patent No. 2881374
In the construction sludge treatment method of the publication, since the control is performed by detecting the stirring load, the characteristics such as the concentration and specific gravity of the input sludge (dredge soil) cannot be taken into account, so the specific gravity and strength of the treated soil as a product. In addition, although this treatment method can finish the treated soil to one having a minimum strength or more, it has a problem that the consumption of cement amount may be too large to be ignored. Further, the technique disclosed in JP-A-5-98663, which is the above-mentioned conventional technique, is the treatment of dredged soil, but since the solidifying material such as cement is a powder, when it is supplied to a continuous mixer, it is conveyed. Since it is mixed while being mixed, the cement that is the solidifying material and the dredged soil cannot be mixed sufficiently, and especially in the case of a continuous mixer, the proportion of the solidified material of the dredged soil cannot be corrected, resulting in a decrease in hardness and strength. There is a problem that the treated soil will have unevenness, and since the lower limit of the strength of the treated soil must be secured, the solidification material is set to the input amount for obtaining the lower limit of the strength of the treated soil. There is also a treated soil part that is stronger than necessary in order to put more solidification material than necessary,
There was also a problem that the amount of solidifying material inevitably increased.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to appropriately mix the solidifying material into the dredged soil without waste when the solidified material is added to the dredged material for processing. ,
Moreover, it is an object of the present invention to provide a method for treating dredged soil, which can be arbitrarily finished so that the properties of the treated soil of the final product have a specific gravity and strength suitable for construction without complicating the process.

[0005]

In order to solve the above-mentioned problems, the invention of claim 1 is to add the solidifying material to the dredged soil and to process the dredged soil.
Both of these are measured and the measured values are adjusted to the dredged soil.
Injecting rectified water to allow both specific gravity and concentration within the specified tolerance range
It is prepared so that it will be inside and supplied to the mixer , and the solidifying material is separately weighed and poured into a liquid to be supplied to the mixer.
Is operated without discharging while receiving the adjusted dredged soil and the liquid solidifying material, and when the dredged soil in the mixer reaches the specified volume, the supply with the dredged soil is stopped and the The method for treating dredged soil is characterized in that treated soil mixed with a mixer is discharged after the operation of. In order to solve the above-mentioned problem, the invention of claim 2 is to add a solidifying material to the dredged soil and process it, in which the specific gravity of the dredged soil and
And both concentrations are measured, and the measured values are recorded in the dredged soil.
Inject adjusted water to adjust both specific gravity and concentration
Was prepared so as to囲内, supplies the adjusted dredged material to the mixer and transported in the screw feeder, the screw off
Dredging when the motor load driving the feeder exceeds a certain level
Air is blown into the soil, and the solidified material is separately weighed and poured into it.
It is liquefied and supplied to the mixer, which operates while receiving the supply and without discharging, and the specific gravity and weight of the dredged soil in the mixer.
Calculate the volume to be input to the mixer from, and stop the supply with the dredged soil when the volume reaches the predetermined volume, and discharge the treated soil mixed in the mixer after the operation for a predetermined time. It is a characteristic method of treating dredged soil.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Here, one embodiment of a method for treating dredged soil suitable for the present invention will be described with reference to the drawings. Figure 1
Shows the concept of this embodiment, and FIG. 2 is a flowchart thereof. First of all, the dredged soil A dredged from the seabed,
It is directly excavated and transferred from the seabed, or carried by a dredged sand carrier and put into a dredged material receiving hopper represented by reference numeral 1 from a bucket or the like. The dredged soil A introduced into the dredged soil receiving hopper 1 is removed by a coarse screen 2 arranged at the bottom of the hopper 1 to remove foreign matters such as large stones and coarse dust, and transferred to the demolition machine 3. The demolition machine 3 unravels the clumps of dredged soil A, and at the bottom of the demolition machine 3, measures the concentration of dredged soil A with a densitometer 31 and the specific gravity with a hydrometer 32, and the concentration and specific gravity of the dredged soil A are large. In this case, the seawater is thrown into and supplied to the demolition machine 3 by the seawater thrower 33 so that it falls within a predetermined range.
At this time, when the amount of dredged soil A in the demolition machine 3 is below a certain amount, the dredged soil receiving hopper 1 is newly loaded with a heavy machine or the like. Input A, and stop when the amount of dredged soil A in the demolition machine 3 reaches a specified amount. This seawater injector 33 processes the data obtained from the densitometer 31 and the pycnometer 32 by the arithmetic controller 34 to calculate an appropriate seawater input amount, and the pump 36 while measuring the seawater input amount by the flowmeter 35. The seawater in an appropriate range is controlled and supplied to the demolition machine 3. Of course, for adjusting the concentration and specific gravity of dredged soil, the adjusted water may be river water, tap water, or groundwater instead of seawater. When the concentration or specific gravity is less than a certain level, for example, when the concentration is thin and close to water, the solidifying material is increased to adjust the specific gravity and strength of the treated soil to be within a certain range as described later. . In order to make the quality of the treated soil as a product more uniform, it is sufficient to finely adjust the concentration and the specific gravity and the solidifying material at the same time. Next, the dredged soil B adjusted to have a predetermined concentration / specific gravity range by the demolition machine 3 is transferred to the screw feeder 4. In addition, it may be disliked to add adjusted water to the dredged soil A because its strength becomes weaker, but in this case, the strength and specific gravity of the treated soil are adjusted only by the solidifying material, and the seawater thrower is used.
From 33, the seawater that is the adjusted water will not be input. The screw feeder 4 puts a predetermined amount into the mixer 5, but when the drive load detector 42 of the motor 41 of the screw feeder 4 detects a load above a certain level, the controlled air is supplied by the compressor 44 of the air feeder 43. Air is mixed into the dredged soil to ensure proper fluidity, the screw feeder 4 is smoothly driven, and a certain amount of the dredged soil B is charged into the mixer (mixer) 5.

On the other hand, the cement as the solidifying material is stored in the solidifying material silo 6, but a part of the cement is transferred to the solidifying material storage bin 62 by the blower 61. Then, a rotary feeder 64 and a gate 65 for supplying a predetermined amount of cement to the weighing hopper 63 are provided at the bottom of the solidified material storage bin 62, and a signal from a weighing scale 66 for weighing the weighing hopper 63 and a specific gravity meter 32 are provided. The signal from the densitometer 31 is input to calculate the required cement amount by the arithmetic controller 67, and the rotary feeder 64 is provided so that the calculated amount of cement is supplied to the weighing hopper 63.
And controls the operation of gate 65. Next, when a predetermined amount of cement is supplied to the weighing hopper 63, the gate 65 is closed, the gate 68 at the bottom of the weighing hopper 63 is opened, and the process proceeds to the step of mixing and introducing cement, which is a solidifying material, into the mixer 5. As described above, a predetermined amount of cement weighed into the mixer 5 may be directly fed into the mixer 5 from the gate 68. If necessary, the cement is supplied to the transport mixer 7 as in the present embodiment, and the pump 71 is used. Alternatively, water may be added by the water injector 72 to make it liquid state in advance and then supplied to the mixer 5. In this case, if the solidifying material is continuously conveyed and water is continuously injected, the treatment process becomes simpler. In any case, when a fixed amount of the solidifying material is continuously charged into the mixer 5 and the total amount of the weighing hopper 63 is supplied, the charging into the mixer 5 is completed.

In the mixer (mixer) 5, the dredged soil B adjusted to an appropriate range of concentration and specific gravity and the calculated predetermined amount of solidifying material (including liquid) are charged, and the load cell 51 of the mixer 5 is used. Since the specific gravity is measured by measuring the weight with a (weight scale), these data are calculated by the calculation controller 53, and the predetermined volume of the dredged soil B and the solidifying material at which the mixer 5 operates efficiently are input. To be done. When the prescribed volumes of both have been added, the gate 45 of the screw feeder is closed and mixed for a certain period of time. In this way, the batch S of the mixer 5 uniformly mixes the treated soil C to the mixer 5
It is temporarily stored in the product hopper 8 via the gate 52, is pumped through the transfer pipe 83 by the pump 82 of the pumping device 81, and is supplied to the landfill or the underwater casting site.

[Operation] Since the apparatus used in this embodiment has the above-mentioned configuration, it operates as follows. In the flowchart of Fig. 2, the dredged soil A is received from the seabed by the dredged soil receiving hopper 1, the screen 2 removes large stones and coarse dust, and the sludge disintegrator 3 loosens large lumps to measure the concentration of the dredged soil. 31 and specific gravity with a pycnometer 32 and dredged soil A
When the concentration and the specific gravity of the seawater are large, the seawater is supplied from the pump 34 while being measured by the flowmeter 33 so that the seawater falls within a predetermined range. In this embodiment, seawater, which is easy to secure at the landfill site, was used as the adjusted water for the dredged soil, but it goes without saying that it may be river water, tap water, or groundwater. Explaining the supply amount of seawater (adjusted water) described above, usually, in the landfill site, the property of the treated soil, which is the final product used for landfill, is often specified by the specific gravity and strength for each landfill site.

For example, as shown in FIG. 3, in order to obtain the instructed treated soil as to the properties of the treated soil which is the final product, it is assumed that the concentration in the disintegrator 3 is 30 to 30 in advance by a test. The data that 40% and the specific gravity are in the range of 1.3 to 1.45 are obtained, and a table of the relationship between the specific gravity of the dredged soil A to be used and the amount of water added for each concentration is created and stored in the storage means of the arithmetic and control unit 34. Store. Then, the necessary table is read from the concentration and specific gravity detected at the site by the arithmetic unit 34 (FIG. 3 is a tentative table, but the gradient of concentration and specific gravity in the graph varies depending on the soil quality), and the demolition machine. The concentration of the dredged soil concentration meter 31 in 3 is 50%, and the specific gravity of the specific gravity meter 32 is 1.
When it is detected that the concentration is 30 to 40% and the specific gravity is 1.3 to 1.45, it is necessary to set the concentration in FIG.
In this case, it is only necessary to add the amount of seawater added in the range of 350 liters to 420 liters, and calculate this to control the seawater feeder 37 (actually, the amount of seawater added is of course the amount of dredged soil. It depends on the amount of treatment, and the amount of water increases as the amount of treatment increases.) Regarding the amount of water added, the properties of the dredged soil differ from site to site, and the specific gravity and strength of the instructed landfill soil differ. Therefore, the concentration / specific gravity slope table in the graph shown in Fig. 3 is read each time. Controlling the seawater input device 37 based on this, but if the concentration and specific gravity within the allowable range cannot be achieved by just inputting seawater, change the amount of cement in the solidifying material or the liquid concentration of the solidifying material to change the product. To ensure the specified specific gravity and strength of the treated soil. In this case, prioritize the adjustment of the concentration of the densitometer and the specific gravity of the pycnometer,
If it still cannot be adjusted within the allowable range, increase the amount of solidified material so that the specific gravity and strength of the treated soil are within a certain range, but if you want to make the quality of the treated soil as a product more appropriate, Is to finely adjust while simultaneously adjusting the concentration and specific gravity and the solidifying material. Note that the arithmetic and control units 34 and 67 cooperate with each other to calculate an appropriate amount of seawater and solidifying material that are related to each other. Both the concentration and the specific gravity are measured in this example because the approximate properties of the dredged soil such as the dredged soil with a large amount of sand or the clay is known from both the numerical values, and the solidified material of the solidified material is based on this numerical value. Since the amount is also appropriately controlled, it is possible to prevent the use of the solidifying material more than necessary to increase the strength of the treated soil more than necessary, and to prevent the wasteful use of the solidifying material. If it is not strictly required that the specific gravity and strength of the treated soil be within the permissible range, a control system for the input amount of the solidifying material may be omitted. Further, even with these adjustments, the dredged soil that does not fall within the allowable range of specific gravity and strength, which indicates the properties of the treated soil as the final product, can be known in advance by the test, so such dredged soil is supplied to the dredged soil receiving hopper 1. do not do. In addition, if you do not like to feed the adjusted water to the dredged soil A, you can control the strength and specific gravity of the treated soil by controlling only the amount of the solidifying material, and the seawater that is the adjusted water cannot be fed from the seawater feeder 33. Not performed.

In this way, the dredged soil B having almost uniform concentration and specific gravity is supplied to the screw feeder 4, and a fixed amount is continuously fed from the screw feeder 4 to the mixer 5. At this time, the screw feeder 4 continuously supplies the dredged soil, but the amount of the dredged soil may not be constant even if it is within the allowable range. In order to solve this, as a result of intensive studies by the present inventors, in this case, it was found that the motor load was above a certain level, and by blowing air into the dredged soil, the motor 41 of the screw feeder 4 was
By reducing the load, the feed amount could be kept constant when the dredged soil transfer amount was within the allowable range. Specifically, when the load of the motor-driven load detector 42 is large, air is fed from the pump 43 so that the detected load falls below a predetermined value, and the air is mixed to operate the screw feeder 4 smoothly. ing.

On the other hand, a portion of the cement as a solidifying material is transferred from the solidifying material silo 6 to a solidifying material storage bin 62 by a blower 61 and a predetermined amount of cement is transferred to a weighing hopper 63. This predetermined amount is the amount of cement used for one batch of the mixer 5, and is related to the strength of the treated soil of the final product, but it is the required amount calculated by a preliminary test from the strength of the indicated landfill treated soil. Is the amount controlled by the control system described above. And, in the embodiment of the present invention, unlike a conventional continuous mixer, a batch type mixer is used for the dredged soil and the solidifying material.
By using the (mixer 5), sufficient mixing can be performed, and the proportion of the solidifying material in the dredged soil can be adjusted to the mixer 5 for each batch, so that the strength and specific gravity can be made appropriate. Moreover, the specific gravity is measured by measuring the weight with the load cell 51 (weigh scale) of the mixer 5, and these data are calculated by the arithmetic controller 53 so that the mixer 5 always has a constant volume of dredged soil.
Mixer 5 because B and the solidifying material are put in
Can be driven efficiently. Thus, if the dredged soil B, which is almost uniform and has a specific density and specific gravity, and the preset solidifying material are mixed by the mixer 5 for a certain period of time, the landfilled soil having a certain specific gravity and a certain strength and the underwater pouring are carried out. Treated soil will be obtained.

It is needless to say that the present invention is not limited to the above-mentioned embodiment unless it impairs the features of the present invention. For example, in this embodiment, both the values of concentration and specific gravity are within the permissible range. However, if the content of the instruction is one of specific gravity and concentration, only one of them may be controlled so as to be within the allowable range. In addition, although seawater was used as the adjusted water in the present embodiment, river water, tap water, or well water may be used. In addition, the liquefaction process of the solidified material, such as the conveyer / mixer 7 and the water injector 7
You may omit the third grade.

[0014]

As described above, according to the first aspect of the invention, when the solidified material is added to the dredged soil for treatment,
Measure both specific gravity and concentration of dredged soil in a demolition machine
Then, inject the adjusted water into the dredged soil and compare the measured values.
Adjust both weight and concentration to within specified tolerances.
Manufactured, supplied to a mixer , separately weighed solidification material and poured water
It is liquefied and supplied to the mixer, which is the adjusted dredge.
It operates without discharging while receiving the soil and liquid solidifying material, and when the dredged soil in the mixer reaches the specified volume, the supply with the dredged soil is stopped and the mixer is operated after the operation for a predetermined time. Since this is a method of treating the dredged soil that discharges the treated soil mixed in, when adding the solidifying material to the dredged soil and treating it, the solidifying material can be properly mixed into the dredged soil, and the solidifying material is added more than necessary. It is possible to prevent the inconvenience of increasing the strength of the treated soil more than necessary by inputting it, eliminating the wasteful use of the solidifying material, and unlike the conventional continuous mixer for the treatment of dredged soil, it solidifies with the dredged soil. Can be mixed sufficiently by using a batch type mixer, and the ratio of solidified material of dredged soil can be adjusted to the appropriate level for strength and specific gravity because the input amount to the mixer can be modified for each batch. The effect is obtained, also in the mixer
The weight of the dredged soil and the specific gravity of the dredged soil
From these data, the mixer can
The volume of dredged soil and solidifying material can be added, and the mixer
The effect is that you can always drive efficiently.
It Furthermore, the process is not complicated and the property of the treated soil of the final product is finished to have a specific gravity and strength suitable for landfilling, submersion, etc., that is, strength and specific gravity can be freely set to a certain degree. It has the effect of being able to finish treated soil with a specific gravity and strength that suits.

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Delete

According to the invention of claim 2, in which process the addition of solidified material dredged soil, the dredged material in Kaidoro machine
Both specific gravity and concentration are measured, and the measured values are
Adjusting both specific gravity and concentration by injecting adjusted water into the dredged soil
Acceptable as prepared comprised within the range, and supplies the adjusted dredged material to the mixer and transported in the screw feeder, said disk
The motor load that drives the Liu feeder exceeds a certain level
Then, blow air into the dredged soil and weigh the solidified material separately.
Water is poured and liquefied and supplied to the mixer, which operates without discharging while receiving the supply, and the ratio of dredged soil in the mixer
Calculate the volume input to the mixer from the weight and weight,
The effect according to claim 1, which is a method for treating dredged soil, in which the supply with the dredged soil is stopped when the volume reaches a predetermined volume, and the treated soil mixed with the mixer is discharged after the operation for a predetermined time. In addition, since the screw feeder is used to transfer the dredged soil, the operation as a system is easy, the operation of the screw feeder is smooth, and the motor load is low.
I tried to blow air when the temperature exceeded a certain level, so
It is possible to reduce the load on the tar, and as a result, it is possible to transfer and supply a certain amount of dredged soil and obtain a treated soil of a certain quality.

[Brief description of drawings]

FIG. 1 is an explanatory view showing the overall concept of a preferred embodiment of the present invention,

FIG. 2 is an overall flow chart diagram of a preferred embodiment of the present invention;

FIG. 3 is a diagram showing a graph for explaining the relationship between the amount of water added, the specific gravity, and the concentration of dredged soil according to an example of the present invention.

[Explanation of symbols]

A, B ... Dredged soil C ... Treated soil (product) 1 ... Dredging material receiving hopper 2 ... screen 3 ... Slipping machine 31 ... Densitometer 32… Specific gravity meter 33 ... Seawater thrower 34,53,67 ... Arithmetic controller 35 ... Flowmeter 36,71,82… Pump 4 ... screw feeder 41 ... Motor 42 ... Load detector 43 ... Air injector 44 ... Compressor 5 ... Mixer 51,66… Load cell (weighing scale) 45,52,65,68… Gate 6 ... Solidifying material silo 61 ... Blower 62 ... Solidifying material storage bottle 64 ... Rotary feeder 7 ... Transport mixer 72 ... Water injector 8… Product hopper 81 ... Pumping device 83 ... Transfer piping

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-5-98663 (JP, A) JP-A-59-23795 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) E02F 7/00

Claims (2)

(57) [Claims] 1. When adding a solidifying material to the dredged soil and treating it, both the specific gravity and the concentration of the dredged soil are measured by a demolition machine.
Inject the adjusted water into the dredged soil
Make sure that both specific gravity and concentration are within specified tolerances
Prepared by supplying to the mixer, and were weighed separately solidified material injection
Liquefied and fed to the mixer, which is controlled by the dredger.
It operates without discharging while receiving the dredged soil and the liquid solidifying material, and when the dredged soil in the mixer reaches the specified volume, the supply with the dredged soil is stopped and mixing is continued after the operation for the specified time. A method for treating dredged soil, which comprises discharging treated soil mixed by a machine. 2. When adding a solidifying material to the dredged soil and treating it, both the specific gravity and the concentration of the dredged soil are measured by a demolition machine.
Inject the adjusted water into the dredged soil
Both the specific gravity and the concentration are adjusted to be within a predetermined allowable range, and the adjusted dredged soil is transferred by a screw feeder and supplied to a mixer, and the screw feeder is driven.
When the motor load is above a certain level, air is blown to the dredged soil.
The solidification material is separately weighed, poured into water and supplied in liquid form to the mixer.The mixer is operated without being discharged while receiving the supply, and the mixer is determined from the specific gravity and weight of the dredged soil in the mixer. Throw in
The dredged soil is characterized by calculating the volume to be entered , stopping the supply with the dredged soil when the volume reaches the prescribed volume, and discharging the treated soil mixed by the mixer after the operation for a prescribed time. Processing method.