JPH10212886A - Slurry treatment system and its system for slurry shield method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slurry treatment system thickening objective slurry to a required specific gravity in order to improve it in the subsequent process. SOLUTION: This slurry treatment system for the slurry shield method is provided with the first measuring part 72 of specific gravity of the feed slurry to a wet cyclone device 18 for slurry treatment and the second measuring part 74 of thickened slurry classified as the underflow slurry by the wet cyclone device 18. This system is provided with a controller 110 controlling the constriction opening of the wet cyclone device 18 in accordance with an aimed specific gravity on the basis of the specific gravity of the feed slurry and further, correcting the constriction opening of the cyclone device on the basis of the specific gravity of the thickened slurry so as to approach an aimed specific gravity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a muddy water treatment system and a muddy water treatment system for a muddy water method, and more particularly to a muddy water treatment system for concentrating a slurry for reforming a slurry and a muddy water treatment system for a muddy water method.

[0002]

BACKGROUND ART Conventionally, muddy water treatment systems have been widely used in various fields. In particular, in the field of the muddy water method, for example, in a shaft excavation method using a stabilizing liquid, a muddy water shield method, or the like, it is used to treat slurry as muddy water used for construction. Here, the slurry is a liquid in which water and fine particles are mixed, and includes a stable liquid for the underground continuous wall and muddy water in a muddy water shield method or the like.

[0003] Such a muddy water treatment system is usually installed on the ground, so that a small installation space and a flexible layout are required due to the restriction of the site site, and the muddy water from the construction site is efficiently removed. Processing ability is also required.

[0004] For example, in the case of excavating a face using a muddy shield machine, muddy water used for stabilizing the face in the muddy shield machine becomes a slurry mixed and stirred with excavated earth and sand. Returned to the muddy water treatment facility.
In the muddy water treatment equipment, as described above, the earth and sand component is separated and removed from the returned slurry, the necessary components are adjusted, and then the slurry is sent again to the shield machine.

[0005] The above-mentioned muddy water treatment equipment usually includes a primary treatment equipment and a secondary treatment equipment.

[0006] The slurry sent from the muddy shield machine to the ground is first treated in a primary treatment facility and then stored in a regulating tank. In the primary treatment facility, sand and gravel with a particle diameter of 74 μm or more are removed using a liquid cyclone, and further sieved through a vibrating sieve to form a slurry containing silt or clay of 74 μm or less and into a conditioning tank. Can be stored. Sediment such as sand and gravel separated in the primary treatment facility is stored in a hopper via a belt conveyor, and is discharged as dumping by a dump truck or the like.

[0007] The slurry stored in the adjusting tank is subjected to component adjustment by adding a thickener and the like by a mud making facility, and water is supplied from a fresh water tank to adjust the density thereof. Is performed, and is sent again to the shield machine via the mud pipe.

[0008] When the components are adjusted in the adjusting tank, the slurry in the adjusting tank overflows due to the water sent from the fresh water tank. This overflowed slurry is stored in a surplus mud tank as surplus mud. This excess mud is treated in a secondary treatment facility, separated into water and other silt clay, and the separated silt clay is supplied to the hopper in a modified state. The earth and sand stored in the hopper is discharged as dump soil by a dump truck or the like, and is transported to an intermediate waste treatment plant or the like.

Conventionally, in this secondary treatment facility, a coagulant is added to muddy water extracted from an excess muddy water layer, and the coagulant is compressed at an extremely high pressure by a filter press to separate water and other sediment components. Was. Then, the separated water was discharged through a tertiary treatment facility, and the sediment component was carried out in a hardened state, and was carried into a hopper by a belt conveyor.

However, in such a method using a filter press, the slurry as surplus mud must be compressed at an extremely high pressure, so that the filter press itself must have a very high mechanical strength. For this reason, the whole system becomes large and expensive.

[0011] In order to solve such a problem, there has been proposed a muddy water treatment facility in which a slurry as surplus muddy water is concentrated using a liquid cyclone in a secondary treatment facility, and the concentrated slurry is modified by adding a modifier. It has been done.

However, a cyclone used for classifying muddy water having a small particle size such as silt or clay requires a small and accurate control. For this reason, the muddy water treatment equipment according to this proposal is provided with a device for detecting the specific gravity of the slurry supplied to the cyclone, and is configured to control the throttle opening of the apex valve of the cyclone based on the detected specific gravity.

However, even when the slurries to be treated have the same specific gravity, if the component ratios of the silt and the viscosity contained therein are completely different, the opening of the apex valve is simply adjusted based on the specific gravity of the slurries to be treated. If you do, the specific gravity of the resulting concentrated slurry will vary,
There is a problem that it is difficult to obtain a concentrated slurry having a predetermined specific gravity and of a stable quality.

In particular, when the slurry to be treated is modified by adding a modifier in a subsequent step, if the specific gravity of the concentrated slurry is 1.4 or less, it is difficult to modify the concentrated slurry. Since the problem that the earth and sand cannot be carried out in the state occurs, measures for the problem are important.

An object of the present invention is to provide a muddy water treatment system and a muddy water treatment system for a muddy water method capable of concentrating a slurry to be treated to have a desired specific gravity for reforming in a subsequent step. It is in.

[0016]

In order to achieve the above object, the present invention is directed to a first specific gravity measuring means for measuring a specific gravity of a slurry supplied to a hydrocyclone apparatus for slurry processing, Specific gravity measuring means for measuring the specific gravity of the concentrated slurry classified as under muddy water in a liquid cyclone device for use, and controlling the throttle opening of the liquid cyclone device to a target specific gravity based on the specific gravity of the supplied slurry. And control means for correcting and controlling the throttle opening of the liquid cyclone device so that the value approaches the target specific gravity, based on the specific gravity of the concentrated slurry,
The feed slurry is concentrated for slurry reforming. Here, the concentrated slurry is a slurry that has been classified (concentrated) by a liquid cyclone or the like. The density of the slurry is higher than that of the slurry before classification, the fluidity of the slurry is reduced, but the slurry is not lost. That is.

Here, the first and second specific gravity measuring means may be means for measuring the specific gravity itself,
Alternatively, a measuring means of a type which measures the density of the slurry and converts the density into a specific gravity may be used.

According to the muddy water treatment system of the present invention, the first
Based on the specific gravity of the supplied slurry measured by the specific gravity measuring means, the opening degree of the throttle of the liquid cyclone device is controlled in accordance with the target specific gravity.

Further, according to the muddy water treatment system of the present invention, the specific gravity of the concentrated slurry classified by the liquid cyclone apparatus is measured by the second specific gravity measuring means, and based on the measured specific gravity, the value is set to the target specific gravity. Is controlled to correct the throttle opening of the hydrocyclone device so as to approach.

Thus, even when the specific gravity of the supplied slurry is the same and the ratio of the components constituting the slurry is different,
The specific gravity of the concentrated slurry classified by the liquid cyclone device can be accurately controlled to a desired value, and the subsequent reforming of the concentrated slurry can be performed stably.

In particular, according to the present invention, since a concentrated slurry having a stable specific gravity can be obtained, the quality of soil modified by injecting a modifying agent in a subsequent step can be made constant. As a result, even if the modified sediment is designated as industrial waste, it is easy to take countermeasures.

The modification means that the surface potential of the fine particles is neutralized by the coagulation action, the particles are easily bonded to each other, and the particles are coarsened by the cross-linking and adsorption action by the hydrogen bond by the polymer functional group. Means that As the concentrated slurry is modified, the apparent particle size becomes larger and the fluidity is lost.

The invention of claim 2 is the invention according to claim 1, wherein a hopper device for storing a concentrated slurry classified by the hydrocyclone device for slurry treatment, and a concentrated slurry provided downstream of the hopper device. Opening and closing means for opening and closing the flow path, wherein the second specific gravity measuring means is provided in the flow path between the hopper device and the opening and closing means, and non-contactly measures the specific gravity of the concentrated slurry flowing in the flow path The control means intermittently shuts off the flow path of the concentrated slurry using the opening / closing means, and at this time the specific gravity of the concentrated slurry measured by the γ-ray hydrometer is determined. And performing the correction control for the hydrocyclone device based on the correction control.

In the muddy water treatment system of the present invention, a configuration is adopted in which the concentrated slurry classified by the hydrocyclone device is temporarily stored in a hopper device and supplied to a downstream slurry reforming device.

Such a configuration is extremely effective when the liquid cyclone device includes a plurality of cyclones for processing the slurry in parallel as in the invention of claim 4. This is because these concentrated slurries classified in parallel by the plurality of cyclones can be collected at one place by a hopper device and sent to a subsequent process.

In this case, it is important how to measure the specific gravity of the collected concentrated slurry. That is, in a state where the concentrated slurry is flowing from the hopper device to the slurry reforming device on the downstream side, the concentrated slurry and the air are mixed, and it is difficult to accurately measure the specific gravity.

On the other hand, in the present invention, the specific gravity is measured in a state in which the flow of the concentrated slurry is stopped by using the opening / closing means, so that the specific gravity of the concentrated slurry can be accurately measured in a state where no air is mixed, thereby enabling the liquid cyclone. Correction control for the apparatus can be performed well, and a concentrated slurry having a stable specific gravity can be obtained.

According to a third aspect of the present invention, in any one of the first and second aspects, the liquid cyclone apparatus for slurry treatment is provided in a secondary treatment facility for wastewater used in a slurry method. The secondary treatment slurry supplied from the next treatment facility is classified and the over muddy water is supplied to the adjusting tank or the excess muddy water tank. This makes it possible to reduce the size and cost of the secondary wastewater treatment equipment used in the muddy water method.

According to a fourth aspect of the present invention, in the third aspect, the liquid cyclone apparatus for slurry treatment classifies the secondary treatment slurry from which components having a particle diameter of 74 μm or more have been removed by primary treatment in parallel. It is characterized by comprising a plurality of cyclones to be treated, and supplying the classified concentrated slurry to a downstream slurry reforming apparatus.

By doing so, it is possible to secure a sufficient amount of muddy water treatment in the secondary treatment facility for wastewater used in the muddy water method.

The invention of claim 4 is more preferably used in combination with the invention of claim 2.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments utilizing a muddy water treatment system according to the present invention will be described below in detail with reference to the drawings, taking a muddy water shield method as an example.

FIG. 1 shows a muddy water shield construction method to which the present invention is applied. The muddy water shield method uses the shield machine 34
, A mud feed system 43, a mud discharge system 47, and a mud water treatment facility 30.

The muddy water sent from the muddy water treatment equipment 30 to the shield chamber 42 inside the shield machine 34 via the mud feeding system 43 and used for stabilizing the face 46 is mixed with the excavated earth and sand in the shield chamber 42 by stirring. The slurry is returned to the muddy water treatment facility 30 via the sludge drainage system 47. In the muddy water treatment facility, earth and sand and the like are classified from the returned slurry, necessary components are adjusted, and then sent out to the shield machine 34 again.

The muddy water treatment equipment 30 is a primary treatment equipment 26
, Secondary treatment equipment 28, adjustment tank 3, excess muddy water tank 12
It is comprised including.

The slurry returned from the sludge drainage system 47 to the muddy water treatment equipment 30 is subjected to classification in the primary treatment equipment 26 into sand and gravel having a particle diameter of 74 μm or more contained in the slurry, and sent to the adjusting tank 3. Can be In the adjustment tank 3, the slurry is sent to the mud feed system 43 after being adjusted in its properties, and the slurry that has not been sent out and overflows is supplied to the surplus mud tank 12. The slurry supplied to the surplus mud tank 12 is sent to the secondary treatment facility to classify silt clay having a size of less than 74 μm, and the classified slurry is sent back to the surplus mud tank 12 for cyclic classification.

The primary processing equipment 26 is provided with a liquid cyclone 17
, Vibrating sieve 4, belt conveyor 8, hopper 13
It is comprised including.

From the sludge exhaust system 47, the primary treatment equipment 26
Is sent to the vibrating sieve 4 and the grit is vibrated to classify gravel and the like. The classified slurry is supplied to the liquid cyclone 17, and the slurry concentrated by the centrifugal action by the rotation of the water stream is sent to the vibrating sieve 4 again to be classified cyclically. The slurry from which soil and the like of 74 μm or more has been removed by the vibrating sieve 4 and the liquid cyclone 17 is sent to the adjusting tank 3. Meanwhile, the classified 7
Earth and sand having a size of 4 μm or more is put into the hopper 13 via the belt conveyor 8 and temporarily stored, and then carried to the disposal site by the dump truck 150.

The secondary treatment facility 28 includes a cyclone system 140, a concentrated slurry tank 20, and a slurry transport and reforming system 142.

Particle size 7 that could not be classified by primary treatment equipment
Silt clay having a size of less than 4 μm is used for cyclone system 14
Classified by 0. The classified slurry is sent back to the excess mud tank 12 and is classified cyclically. On the other hand, the classified silt clay and the like are concentrated and sent to the concentrated slurry tank 20. Furthermore, after being sent from the concentrated slurry tank 20 to the slurry transport / reforming system 142 for reforming, it is transported to an industrial waste intermediate treatment plant or the like.

FIG. 2 shows an overall view of the cyclone system 140. The cyclone system 140 includes a cyclone device 18, a pipe 120 that is a path from the surplus mud tank 12 to the cyclone apparatus 18, a cyclone pump 90 provided on the pipe 120, and a path from the cyclone apparatus 18 to the surplus mud tank 12. Pipe 122 and the cyclone device 1
8 and a pipe 124 which is a path from the concentrated slurry tank 20.

The slurry is pressurized by the cyclone pump 90 from the excess mud tank 12 and supplied to the cyclone device 18 through the pipe 120. In addition, the cyclone pump 90
A strainer 100 is provided on a pipe 120 between the and the cyclone device 18, and when the slurry is supplied to the cyclone device 18, soil particles having a particle diameter of 1.5 mm or more are removed by the strainer 100.

The slurry supplied to the cyclone device 18 is classified by the centrifugal action of the cyclone, and the slurry having a small particle size is supplied to the excess mud tank 12 through the pipe 122. On the other hand, the slurry having a large particle diameter is supplied to the concentrated slurry tank 20 through the pipe 124. A hopper 15 is provided between the cyclone device 18 and the pipe 124. The concentrated slurry discharged from the cyclone device 18 is temporarily stored in the hopper 15, and then passes through the pipe 124 to the concentrated slurry tank 20. Supplied.

The cyclone device 18 is specifically shown in FIG.
As shown in (B), the hydrocyclones 18-1 to 18-
It is configured to include twelve hydrocyclones. Further, as shown in FIG. 3A, all the concentrated slurries discharged from these 12 liquid cyclones are collected in one hopper 15.

FIG. 4 shows a sectional view of each hydrocyclone. The hydrocyclone comprises an inlet pipe 130 into which the supply slurry flows, and an upstream pipe 132 from which over mud is discharged.
The inflow pipe 130 is connected to the side and the upstream pipe 13 is
2, a conical portion 138 connected to a lower portion of the cylindrical portion 136, and a downstream pipe 134 connected to a lower portion of the conical portion 138 to discharge the concentrated slurry.
It is comprised including. An apex valve 86 is provided so as to cover the side surface of the downstream pipe 134.

As shown in FIG. 2, the excess muddy water tanks 12 to 2
The slurry sent to the next processing equipment 28 is pressurized by the cyclone pump 90 and supplied to the cyclone device 18 through the pipe 120. This slurry is called the feed slurry. The strainer 100 is provided on the tube 120, and the one having a large particle size in the slurry is the strainer 1
00 removes from the slurry. The feed slurry is
Those having a small particle size, which are centrifuged inside the cyclone device 18, are discharged from the upstream pipe 132 and sent to the surplus mud tank 12 through the pipe 122. This mud is called over mud. The muddy water sent to the surplus muddy water tank 12 is sent to the adjusting tank 3 for circulating use. In some cases, the slurry is sent from the adjusting tank 3 to the cyclone system 140, sent back to the adjusting tank 3, and recycled. On the other hand, those having a large particle diameter are collected and concentrated below the inside of the conical portion 138, supplied to the hopper 15 through the downstream pipe 134, and sent to the concentrated slurry tank 20 through the pipe 124. This slurry is called a concentrated slurry. The concentrated slurry sent to the concentrated slurry tank 20 is supplied to the slurry transport reforming system 14.
Sent to 2.

FIG. 5 shows a slurry transport reforming system 142.
FIG. The slurry transport reforming system 142 includes:
As shown in FIG. 5, it is configured to include a modifier tank 116, a static mixer 102, a stabilizer tank 118, and a mixer 104.

The concentrated slurry sent from the concentrated slurry tank 20 to the slurry transport / reforming system 142 is pressurized by a pump 92 provided on a pipe 126 which is a path between the concentrated slurry tank 20 and the static mixer 102. , Through tube 126 to static mixer 102. At the inlet of the static mixer 102, a pressure is applied by a pump 94 provided on a pipe 128 which is a path between the modifier tank 116 and the static mixer 102, and the modifier supplied through the pipe 128 is statically supplied. It is added to the concentrated slurry in the mixer 102. The concentrated slurry after the addition of the modifier is stirred inside the static mixer 102 and transported in a fluidized state,
It is supplied to the inlet of the mixer 104. The concentrated slurry is added with the stabilizer supplied from the inlet of the mixer 104 through the mixer 106 which is a path between the stabilizer tank 118 and the mixer 104, and is stirred and transported inside the mixer 104. The length of the mixer 104 is adjusted so that the concentrated slurry is reformed immediately before the outlet. The concentrated slurry after the addition of the modifier and the stabilizer is stirred and reformed immediately before the outlet of the mixer 104, and then the dump truck 15
The waste is transported to an industrial waste intermediate treatment plant by 2.

The control of the addition of the modifying agent in the slurry transport reforming system 142 is performed by the transport reforming control device 112 as follows. A flow meter 80 and a γ-ray density meter 82 are provided on a pipe 126 between the pump 92 and the static mixer 102, and a motor 170 for controlling the mixer 106 for adding the stabilizer is provided in connection with the mixer 106. I have. The flow rate of the concentrated slurry is measured by the flow meter 80, and the specific gravity of the concentrated slurry is measured by the γ-ray density meter 82, and each measurement data is sent to the transport reforming control device 112. The transport reforming control device 112 controls the pump 94 for pumping the modifier and the motor 170 for controlling the mixer 106 for supplying the stabilizer based on the obtained measurement data. The amount added and the amount of stabilizer added are controlled. That is, when the specific gravity of the concentrated slurry supplied to the static mixer 102 is high or when the flow rate is small, a small amount of a modifier or a stabilizer is added, and when the specific gravity is low or the flow rate is large,
Many modifiers and stabilizers are added.

According to the present embodiment, since the length of the static mixer 102 and the amount of the modifier to be added are adjusted, the concentrated slurry is passed through the static mixer 102 while being kept in a fluidized state. Can be supplied to The static mixer 102 is configured by alternately arranging a plurality of elements in which a rectangular plate is twisted 180 degrees in the forward direction and elements in which the rectangular plate is twisted 180 degrees in the opposite direction, and is provided with a closed casing. Because of the pressure state, the stirring and mixing can be performed efficiently. The modifier is not particularly limited as long as it is an acrylic modifier such as acrylamide and sodium acrylate, but acrylamide is preferred. When an acrylic modifier is used, the acrylic component, which is the main component of the polymer modifier, is dissolved in the water contained in the concentrated slurry, and the acrylic modifier is added to the soil particles in the concentrated slurry. Is adsorbed and a cross-linking adsorption action occurs. By adding this modifier to the muddy water, the soil particles become apparently coarse particles, and most of the water in the concentrated slurry is trapped between the coarse particles. (Reformed) state.
Further, the addition of the modifier can be modified in a much smaller amount than before, the time required for the modification is about ten and several seconds,
Since the reformed mud can be carried out by a dump truck, there is also an effect of shortening muddy water treatment time, preventing waste of resources and reducing costs.

Further, since the length and the like of the mixer 104 are adjusted, the concentrated slurry can be reformed near the outlet of the mixer 104, and the diameter of the mixer 104 is reduced to such a size that the modified concentrated slurry is not clogged. Therefore, appropriate reforming treatment can be performed. In this case, by adding a stabilizer to the concentrated slurry, it is possible to maintain stable properties even after the reforming and transport to an industrial waste intermediate treatment plant or the like. At the time of adding the stabilizer, the concentrated slurry is stirred by the static mixer 102 and is in a homogeneous state and a fluidized state, so that the stabilizer can be added satisfactorily. As the stabilizer, a lime-based or cement-based stabilizer is desirable.

Conventionally, large-scale muddy water treatment equipment such as a filter press is required for reforming, and it takes many hours to reform the concentrated slurry. Transportation had to be carried out, which was very costly. According to the present embodiment, since the reforming can be performed in only ten and several seconds, the muddy water treatment time can be shortened, and the dump truck can be continuously loaded on a low-priced dump truck, thereby reducing the cost. In addition, the flow meter 80 and the gamma ray density meter 82 allow the minimum necessary amount of the modifier and the stabilizer to be added to the concentrated slurry. Emissions to treatment plants and the like can also be reduced.

The concentrated slurry tank may have any shape and may be provided separately, or may be provided at the bottom of the shaft. Even when the concentrated slurry is provided at the bottom of the shaft, since the concentrated slurry is in a fluidized state, the concentrated slurry can be transported to the static mixer 102 on the ground through a pipe, so that the area of the ground can be further reduced.

The control flow of the concentrated slurry and the like in the slurry transport and reforming system 142 is as described above. The control flow of the concentrated slurry and the like in the liquid cyclone system 140 is performed as follows centering on the apex valve 86. .

Conventionally, as shown in FIG. 6, the specific gravity of the supplied slurry is measured by a density meter 72 provided in a path between the cyclone pump 90 and the cyclone device 18,
The measurement data is sent to the cyclone control device 110, and the cyclone control device 110 controls the apex valve 86 based on the measurement data. In this control, as shown in FIG. 11, the throttle of the apex valve is changed in accordance with the specific gravity of the supplied slurry so as to control the specific gravity of the concentrated slurry to be constant. However, as described above, when the slurry is cyclically supplied from the excess mud tank 12 to the cyclone device 18, as shown in FIG. 12, the specific gravity of the supplied slurry immediately after the start of the classification process in the cyclone device 18 is 1. 27 and the specific gravity of the concentrated slurry is 1.6
6, the specific gravity of the supply slurry was 1.21 and the specific gravity of the concentrated slurry was 1.46 in the measurement 40 minutes after the start of classification, whereas the change in the supply slurry was 0.06. The change amount of the concentrated slurry is 0.20, which is three times different. As described above, when the change in the specific gravity of the concentrated slurry is large relative to the change in the supply slurry, even if the opening degree of the apex valve 86 is changed in accordance with the change in the specific gravity measured by the density meter 72, Since it is significantly different from the change in specific gravity, it is extremely difficult to set the specific gravity of the concentrated slurry to a desired specific gravity of 1.4 or more, which is a specific gravity suitable for the reforming treatment.

In this embodiment, as shown in FIG. 7, a hopper 15, a γ-ray density meter 74, and a sampling valve 8 are provided between the apex valve 86 and the concentrated slurry tank 20.
4 are provided. The specific flow of control is as follows.

As shown in FIG. 2, a density meter 72 is provided on a pipe 120 between the strainer 100 and the cyclone device 18 to measure the specific gravity of the muddy water supplied to the cyclone device 18, and the measured data is obtained by the cyclone control. Sent to the device 110. The cyclone controller 110 controls the apex valve 86 by comparing the measured data with a predetermined reference value stored in advance and setting the optimal aperture of the apex valve 86. The specific gravity of the concentrated slurry discharged from the cyclone device 18 and temporarily stored in the hopper 15 is measured by a γ-ray densitometer 74 provided in a pipe 124 immediately below the hopper 15, and the measurement data is sent to the cyclone control device 110. Sent. The cyclone control device 110 corrects and controls the throttle opening of the apex valve 86 based on the measured data so that the concentrated slurry has a predetermined property. That is,
When the specific gravity is not sufficient, the aperture of the apex valve 86 is reduced, and when the specific gravity is exceeded, the aperture of the apex valve 86 is increased. When the specific gravity is measured by the γ-ray density meter 74, the measurement is performed in a state where the sampling valve 84 provided on the pipe 124 on the downstream side of the γ-ray density meter 74 is closed. Note that the sampling valve 84 is normally open.

According to the present embodiment, since the specific gravity of the concentrated slurry can be maintained at a predetermined value, the processing for adding the modifier after passing through the cyclone device 18 can be optimally performed. A hopper 15 for collecting the concentrated slurry discharged from the cyclone device 18 is provided, a γ-ray density meter 74 for measuring the specific gravity of the concentrated slurry discharged from the hopper 15 is provided, and the specific gravity of the concentrated slurry is measured. By controlling the apex valve 86 based on the measurement data, the specific gravity of the concentrated slurry can be set to a desired value suitable for reforming of 1.4 or more. At the time of this specific gravity measurement, by closing the sampling valve 84, the air contained in the concentrated slurry inside the tube 124 provided with the γ-ray density meter 74 is dissipated upward, and the state of the concentrated slurry is homogenized. Therefore, the specific gravity can be accurately measured.

Further, as shown in FIG. 3B, by providing a plurality of small-diameter hydrocyclones, it is possible to classify silt clay or the like having a small soil particle diameter in parallel and continuously. In addition, small-sized soil particles can be classified in a large amount and at a high speed. In this case, as shown in FIG. 3 (A), even when a plurality of liquid cyclones are provided, the respective concentrated slurries are collected in the hopper 15, so that the processing after the hopper is the same as in the case of a single liquid cyclone. Since the conventional processing facility can be used, the area of the processing equipment on the ground does not become larger than before.

By the way, as shown in FIG. 9, there are various types of soils such as an alluvial clay soil layer and a dirt sandy soil layer in a tunnel excavation route. For this reason, as shown in FIG. 10, the amount of concentrated slurry discharged differs depending on the soil even if the throttle of the apex valve 86 is the same. Further, when the soil quality at the point where the tunnel is excavated changes suddenly, the amount of mud supplied to the excess mud tank 12 also changes suddenly, and the amount of supplied slurry also changes suddenly. In such a case, if the control is performed with priority given to the density, the supply slurry cannot be completely processed, and in the worst case, the tunnel excavation must be stopped. For this reason, it is necessary to treat the concentrated slurry with priority on flow rate rather than on density,
Since the concentrated slurry discharged from the cyclone device 18 is discharged to the atmosphere, it is difficult to measure the discharge amount due to mixing of air or the like.

In this embodiment, as shown in FIG. 8, in addition to the specific gravity measuring device and the like, a flow meter 78 is provided between the density meter 72 and the cyclone device 18, and a flow meter 78 is provided between the cyclone device 18 and the excess mud tank 12. A flow meter 76 is provided therebetween. If the difference between the amount of supplied slurry obtained by the flow meter 78 and the amount of over muddy water obtained by the flow meter 76 is obtained, the amount of concentrated slurry can be obtained accurately. The specific flow of control is as follows.

As shown in FIG. 2, the flow rate of the slurry supplied to the cyclone device 18 is measured by a flow meter 78 provided on a pipe 120 which is a mud path from the excess mud tank 12 to the cyclone device 18. Is done. Further, the flow rate of the excess muddy water is measured by the flow meter 76 provided on the pipe 122 which is a path of the over muddy water from the cyclone device 18 to the excess muddy water tank 12. The measured data is sent to the cyclone controller 110, respectively. In the cyclone control device 110, the cyclone device 18
The difference between the flow rate of the mud supplied to the tank and the flow rate of the over mud is determined. This difference is the flow rate of the concentrated slurry. The apex valve 86 is controlled by the cyclone control device 110 based on the flow rate of the concentrated slurry so as to have a desired flow rate. That is, when the desired flow rate is insufficient, the throttle opening of the apex valve 86 is increased, and when the desired flow rate is exceeded, the throttle opening of the apex valve 86 is reduced. When the flow rate is measured for the first time, the initial values of the flow meter 76 and the flow meter 78 are set as follows.

As shown in FIG. 2, a valve 89 is provided on a pipe 122 between the flow meter 78 and the cyclone device 18 and a valve 87 is provided on a pipe 122 between the cyclone device 18 and the flow meter 76. A bypass valve 88 is provided for connecting a pipe 120 between 78 and the valve 89 and a pipe 122 between the valve 87 and the flow meter 76. Cyclone control device 1
By closing the valve 87 on the pipe 120 and the valve 89 on the pipe 122 by 10 and opening the bypass valve 88, the muddy water in each pipe measured by the flow meters 76 and 78 becomes similar. In this state, the flow meter 7
Initial values are set so that both the values 6 and 78 are equal.

According to the present embodiment, the flow meters 76 and 78
Is provided, the flow rate of the concentrated slurry can be accurately measured. In addition, since the bypass valve 88 and the valves 87 and 89 are provided, the flowmeter 7 is provided.
Since the measured values of the flowmeters 6 and 78 can be made uniform, the initial setting of the flowmeter can be performed accurately, so that the flow rate of the muddy water can be measured accurately.

The throttle opening of the apex valve 86 can be controlled by giving priority to the specific gravity of the concentrated slurry or by giving priority to the flow rate. Normally, as described above, the muddy water treatment is performed in a state where the specific gravity of the concentrated slurry is as high as 1.4 or more as high as possible with priority to specific gravity. However, when the soil quality of the ground of the face changes suddenly, the amount of water in the surplus mud tank 12 suddenly changes, and the processing amount decreases when the priority is given to the density, which may hinder the tunnel excavation. In such a case, it is necessary to maintain the specific gravity of the muddy water at about 1.4, which is the lowest specific gravity that can be reformed, and switch to the flow rate priority. According to the present embodiment, since the specific gravity and the flow rate of the concentrated slurry can be accurately measured, the specific gravity priority control shown in FIG. In this case, by performing the flow rate control shown in FIG. 8, appropriate muddy water treatment can be performed even when the amount of water in the surplus muddy water tank 12 suddenly changes, so that stable tunnel excavation can be performed.

Further, according to the present embodiment, it is also possible to automatically adjust the aperture of the apex valve 86 according to the tunnel excavation position. In this case, as shown in FIG. 9, the geology of the excavation route of the shield machine is previously surveyed by a boring survey or the like, and based on the survey data, the particle size distribution of each excavation area is grasped. It is stored in an internal storage device. In addition, it is set whether the control of the cyclone device 18 in the region is set to the density priority mode or the flow rate priority mode.
Then, the control mode of the cyclone device 18 is switched based on the stored data and the current excavation position. Thereby, it is possible to automatically switch between density priority and flow rate priority.

The application of the present invention is not limited to the above-mentioned muddy water shield method. For example, the present invention can be applied to muddy water treatment in an underground continuous wall method, a reverse method, or the like.

[0068]

[Brief description of the drawings]

FIG. 1 is an overall view of a muddy water shield method according to an example of an embodiment of the present invention.

FIG. 2 is an overall view of the cyclone system shown in FIG.

3 is a detailed view of the cyclone system shown in FIG. 2, (A) is a side view, and (B) is a plan view.

FIG. 4 is a sectional view of the hydrocyclone shown in FIG.

FIG. 5 is an overall view of the slurry transport reforming system shown in FIG.

FIG. 6 is a functional block diagram showing conventional specific gravity control of a concentrated slurry.

FIG. 7 is a functional block diagram illustrating specific gravity control according to an example of the present embodiment.

FIG. 8 is a functional block diagram illustrating flow control according to an example of the present embodiment.

FIG. 9 is a vertical sectional view of a soil along a tunnel excavation route.

FIG. 10 is a diagram showing a grain size accumulation curve for each soil type in a tunnel excavation route. (A) shows the alluvial cohesive soil layer, (B) shows the sedimentary sandy soil layer, and (C) shows the grain size sedimentary curve of the diluent cohesive soil layer.

FIG. 11 is a diagram showing a specific gravity of a supply slurry and a throttle opening of an apex valve.

FIG. 12 is a diagram showing a change in specific gravity of a supply slurry, an over slurry, and a concentrated slurry.

[Explanation of symbols]

 Reference Signs List 3 Adjustment tank 12 Surplus mud tank 15 Hopper 18 Cyclone device 20 Concentrated slurry tank 70 Density meter 74 γ-ray density meter 84 Sampling valve 86 Apex valve 90 Cyclone pump 100 Strainer 110 Cyclone control device

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shigeru Suzuki 3-10-11 Masago, Mihama-ku, Chiba-shi, Chiba (72) Inventor Masayoshi Yasumoto 2-7-6, Asaya-minami, Suginami-ku, Tokyo (72) Invention Inventor Yoshio Iwai 1-514, Yoshida-cho, Midori-ku, Chiba-shi, Chiba-shi (72) Inventor Iku Sato 1-61 Sakaemachi, Ageo-shi, Saitama

Claims (4)

[Claims] A first specific gravity measuring means for measuring a specific gravity of a slurry supplied to a liquid cyclone apparatus for slurry processing; and a specific gravity measurement of a concentrated slurry classified as under muddy water in the liquid cyclone apparatus for slurry processing. Second to do
Based on the specific gravity of the supplied slurry, the throttle opening of the liquid cyclone device is controlled in accordance with a target specific gravity, and based on the specific gravity of the concentrated slurry, the liquid is adjusted so that its value approaches the target specific gravity. A muddy water treatment system, comprising: control means for correcting and controlling the throttle opening of a cyclone device; and concentrating a supplied slurry for slurry reforming. 2. The hopper device according to claim 1, wherein the hopper device stores concentrated slurry classified by the liquid cyclone device for slurry processing, and an opening / closing means provided downstream of the hopper device to open and close a flow path of the concentrated slurry. And wherein the second specific gravity measuring means is provided in a flow path between the hopper device and the opening / closing means, and a γ-ray hydrometer which measures the specific gravity of the concentrated slurry flowing in the flow path in a non-contact manner. The control means intermittently shuts off the flow path of the concentrated slurry using the opening / closing means, and based on the specific gravity of the concentrated slurry measured by the γ-ray hydrometer at this time, the liquid cyclone device A muddy water treatment system, wherein the correction control is performed on the muddy water. 3. The slurry treatment liquid cyclone device according to claim 1, wherein the slurry treatment liquid cyclone device is provided in a wastewater secondary treatment facility used in a muddy water method, and is supplied from the wastewater primary treatment facility. A muddy water treatment system for a muddy water method, comprising classifying the slurry for secondary treatment performed and supplying the over-muddy water to the adjusting tank or the excess muddy water tank. 4. The plurality of cyclones according to claim 3, wherein the liquid cyclone apparatus for slurry treatment classifies in parallel the secondary treatment slurry from which components having a particle size of 74 μm or more have been removed by primary treatment. And supplying the classified concentrated slurry to a downstream slurry reforming apparatus.