JPS5933007B2 - Separation equipment for muddy water mixed with shear - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method for converting muddy water, which is obtained by mixing excavated soil into muddy water used in muddy shields, underground walls, and other excavation methods that use water supply, into excavated mud and mud-water. The present invention relates to an apparatus for separating and processing.

For example, according to the muddy water shield construction method described above, the muddy water supplied into the shield device from ground equipment serves to prevent the face from collapsing, and also serves to transport excavated earth and sand.

The muddy water circulates between the ground equipment and the shield device, and the muddy water used for carrying out the earth and sand is separated from the earth and sand on the ground and reused.

Conventionally, the separation of slurry mixed with ground water has been carried out by the simplest method of collecting and reusing the mud as clean water in an above-ground settling tank, or by a forced separation method using a vibration device.

However, this method not only requires a lot of processing time, but also has the drawback that fine particles in the pickpocket mix into the muddy water, changing the concentration of the muddy water.Furthermore, in both methods, the collected pickpocket has a low water content. It is expensive, and disposal of the pickpocket itself becomes a problem.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a separator which eliminates the drawbacks of conventional separators, has excellent treatment capacity, and adjusts the concentration of muddy water.

The separation device according to the present invention sends compressed air to muddy water mixed with soot introduced into a tank, forcibly filters and separates the muddy water from the soot, and discharges the soot out of the tank without reducing the pressure inside the tank. It is characterized by

Further, the separation method of the present invention is characterized in that an accumulated filter bed layer made of sandpaper and residual soil in the muddy water is formed above the filter medium layer, and the concentration of the muddy water is adjusted by this accumulated filter bed layer.

If the ingredients and/or content of the sludge mixed into the mud are approximately constant, and the content of fine particles is within an approximately constant range, the thickness of the sediment filter bed layer is maintained constant. As a result, the concentration of the filtered mud water is kept almost constant, so the first separation device of the present invention is applied in this case.

However, if the thickness of the sediment filter bed layer is held constant, the concentration of the filtered mud water will change, such as when the components and/or contents of the slurry vary widely and the content of fine particles changes significantly. This will have an impact on subsequent excavation methods that use muddy water.

Therefore, in such a case, the second separation device of the present invention is applied.

The features of the invention will become more apparent from the following description of the illustrated embodiments.

As shown in FIG. 1, a separation device 10 according to the present invention includes a tank 1 consisting of a main body 12 supported on a base 11 whose upper end can be opened, and a cap 14 that seals the upper end.
6, and there are spaces 17 at 17 in both the upper and lower parts of the tank.
Three filter material layers 18, 1 arranged in the middle part except for b
9 and 20 are provided.

The upper space 17a is essential for introducing slurry and compressed air, as will be described later, but the lower space 1
7b may be omitted, and the filter material layer 20 may be filled up to the lower end of the tank 16.

It is preferable to arrange a fine-mesh wire mesh 22 above the uppermost filter material layer 18.

The uppermost filter layer 18 is formed of fine sand, but in the separation device of the present invention, a sedimentary filter bed layer made of sandpaper and residual soil in muddy water is formed on the upper side of this filter layer. Since the diameter of fine particles contained in muddy water is smaller than that of fine sand, it is easy to pass through the filter layer made of fine sand.
It is desirable to provide the wire mesh 22 with a mesh smaller than the gap provided in the gap.

As mentioned above, in addition to forming the uppermost filtering material layer 18 from fine sand, it is preferable to form the middle filtering material layer 19 from coarse sand and the lowermost filtering material layer 20 from gravel. .

Each layer of filter media is preferably housed in a basket made of wire mesh or filter media that prevents the passage of the respective components, so that the cap 14 can be removed to replace the filter media layer. This is convenient in such cases.

When the uppermost filter material layer 18 is housed in a basket made of wire mesh or filter material, this basket may also serve as the function of the wire mesh 220.

At the bottom of the gravel layer 20, a permeable support plate 24, such as a perforated plate for receiving the filter medium described above, is provided within the body 12 and across it.

The cap 14 is provided with a pipe 26 for introducing high-pressure compressed air into the tank 16, and the limb pipe is connected to a high-pressure air source (not shown) such as a near compressor via a valve. ing.

Similarly, the cap 14 is provided with a pipe 28 for introducing muddy water mixed with shear into the tank 16, and a limb pipe is, for example, a mud removal pump installed in connection with a mud water pressurized shield drilling device (Fig. (not shown) via a valve.

It is preferable that this pipe 28 is provided in the tank on the opposite side to a scraping discharge pipe 38, which will be described later. If this is done, water in the slurry mixed with scraping introduced into the tank from the pipe 28 will be removed from the lower part of this pipe. Since the water is forced downward through the filter medium, the water does not flow out from the drain pipe 38.

Further, on the cap 14, there is provided a drive wheel for driving and rotating an impeller 30, which will be described later and is rotatably suspended by the cap.
A drive device 32 including an electric motor and a speed reducer is provided.

An impeller 30 whose details are shown in FIG. 2 is attached to a rotating shaft 34 extending downward from the drive device 32 through the cap 14 and into the upper space 17a inside the tank.

The impeller 30 includes a large number of blades 36 having a convex arc shape in the rotation direction indicated by an arrow 31 in FIG.

Preferably, the blades 36 are provided with small notches or openings to allow moisture to escape during rotation.

The impeller 30 is arranged in the tank 16 so that a space 39 having a predetermined height H is formed between the upper surface 23 of the wire mesh 22 and the lower end 37 of the blade 36.

The main body 12 of the tank communicates with the upper space 17a at a level approximately equal to the upper surface of the filtering material layer 18.
There is a pipe 38 provided on the peripheral wall for discharging the dehydrated pickpocket, and this pickpocket discharge pipe discharges the pickpocket to the outside of the tank while maintaining high pressure in the upper space 17a inside the tank 16. A rotary pulp 40 is provided for this purpose.

A pipe 42 for discharging filtered muddy water out of the tank is provided at the bottom of the main body 12, and this pipe is connected to a suitable storage tank (not shown) or to a muddy pressurized shield tunnel excavation. Connected to a slurry pump (not shown) associated with the device.

When treating muddy water introduced into the tank 16 through the pipe 28, the impeller 30 is rotated by the operation of the drive device 32, and compressed air is introduced into the tank through the pipe 26.

Due to the action of this compressed air, the ground mixed mud is separated on the wire mesh 22, and the water passes from the uppermost filter material layer 18 to the lower filter material layers 19 and 20 sequentially, and filtration continues. It is forced to flow down toward the lower space 17b and the pipe 42 communicating therewith.

In this case, since a space 39 with a height of H is provided between the upper surface 23 of the wire mesh 22 and the lower end of the blades of the impeller 30,
This pickpocket larger than H is discharged into the pickpocket discharge pipe 38 by the rotation of the blades 36 by the impeller 30.

When residual soil consisting of shear and fine particles in the muddy water is deposited in the space 39, this forms a filter bed layer 41, and the fine particles mixed in the muddy water are filtered by this filter bed layer. The amount is adjusted.

Therefore, the thickness of this deposited filter bed layer 41, that is, the space 39
If the height H of is set appropriately, the concentration of muddy water after filtration will always be kept almost constant.

When the thickness of the deposited filter bed layer becomes greater than H, it is scraped off by the blades 36 of the rotating impeller 300 and discharged into the scraping discharge pipe 38.

The dehydrated pickpockets are continuously discharged to the outside of the tank 16 through the discharge pipe 38 and the rotary valve 40 provided therein, without reducing the pressure inside the tank 16.

In this way, the muddy water introduced into the tank 16 is separated into the muddy water that is discharged outside the tank through the pipe 38 and the muddy water that is discharged outside the tank through the pipe 42 and is reused.

When the amount of fine particles in the slurry is approximately constant, the concentration of fine particles in the muddy water will depend on the thickness H of the filter bed layer 41 made of residual soil deposited in the space 39 as described above. Since it is approximately constant, the relationship between H and concentration may be investigated in advance, and the height Hl and therefore the height of the impeller 300 blades may be fixed.

However, when separating muddy water mixed with sand from an excavation site where the amount of fine particles in the sand is small, the sediment filter layer 4
If the thickness of 1 is kept constant, the concentration of mud will change, which will affect subsequent work.

Therefore, in such a case, a separation device as shown in FIG. 3 is used.

The filtering material layers 18 and 19 are provided in the main body 12, the wire mesh 22 is provided on the upper surface of the upper filtering material layer 18, and the impeller 30 is rotatably mounted above the wire mesh 22. This is the same as the separation device described above.

However, the impeller 30 is formed to be able to move up and down as well as rotate.

A shaft 50 having an impeller 30 at its tip is formed to be movable up and down by a cylinder 52 and rotatably supported by a rod 53 of the cylinder.

It is also possible to use a screw mechanism in place of the cylinder 52.

A key 54 is provided on this shaft 50, and this key 54 is
A hollow shaft 58 rotatably held by a bearing portion 56 of the cap 14 is engaged with a keyway 60 having an axial length larger than the key.

The key 54 and the keyway 60 may be engaged by spline.

The hollow shaft 58 is connected to an electric motor 64 via a gear train 62.

Accordingly, rotating the hollow shaft 58 by the electric motor 64 via the gear train 62 rotates the shaft 50 and thus the impeller 30, allowing the cylinder 52 to raise and lower the shaft 50 during rotation.

It can be considered that as the thickness of the filter bed layer 41 increases, the concentration, that is, the specific gravity, of the muddy water discharged into the pipe 42 decreases proportionally.

In other words, when the specific gravity of the muddy water in the pipe 42 is large,
By increasing the thickness of the filter bed layer 41, the specific gravity of muddy water to be filtered and discharged can be reduced; conversely, when the specific gravity of muddy water in the pipe 42 is small, by decreasing the thickness of the filter bed layer 41, It is possible to increase the specific gravity of muddy water that is filtered and discharged.

Therefore, if the relationship between the specific gravity and the ascending stroke of the impeller is given by the straight line A shown in Fig. 4, when the specific gravity of muddy water is the highest, 1.3, the ascending stroke of the impeller is set to 100 mm, When the specific gravity of muddy water is at the bottom of 1.0, the impeller 30 must have a stroke of 10 to operate the impeller to set its upward stroke to Omrn.
When the specific gravity of muddy water is 1.3, the impeller 30 is raised by H=100mm, and when the specific gravity of muddy water is 1.0, the impeller H=O1, that is, the impeller 3 is used.
The impeller is raised and lowered so that the lower ends of the 00 blades 36 touch the wire mesh 22.

When the specific gravity is in the intermediate specific gravity range, for example, 1.15, the impeller 30 is raised by H=50 mm.

Thus, the preferred specific gravity range for muddy water is 1.09 to 1.21.
If so, the impeller 30 is H=30mm to 70mm
All you have to do is adjust it so that

In this adjustment, for example, the muddy water in the pipe 42 is sampled every 30 minutes to measure its specific gravity, and the impeller 30 is moved up and down by operating the cylinder 52 based on the specific gravity.

For example, a single tube density meter is placed vertically on the outlet side of the tube 42,
It is also possible to calculate the values obtained by measuring from the upper and lower sides of this single-tube densitometer, obtain a signal for operating the cylinder 52, and automatically operate the cylinder 52.

According to the present invention, during the scraping discharge, high pressure is maintained in the upper space of the tank by the rotary valve provided in the scraping discharge pipe, so that the slurry mixed with mud is forcibly separated under the action of compressed air. , the forcibly separated pickpocket can be continuously discharged to the outside of the tank.

Therefore, a large amount of slurry mixed with ground water can be treated in a short time.

Moreover, by depositing shear and fine particles in muddy water to form a filter bed layer, it is possible to capture fine particles suspended in muddy water that would pass through filter media such as sand. The concentration of muddy water can also be adjusted well.

Further, since a filter bed layer is formed on the upper side of the filter medium and the filter bed layer is utilized for filtration, it is only necessary to provide a thin layer as the filter medium, which is economical.

In the above example, fine sand was used in the upper layer, coarse sand was used in the middle layer, and gravel was used in the lower layer as the filter media, but a three-layer structure made of such materials is not essential, and for example, a single layer of only fine sand may be used. It is optional, such as using other materials.

[Brief explanation of drawings]

FIG. 1 is a front view of the first separation device of the present invention, FIG. 2 is a sectional view taken along line 2-2 in FIG. 1, and FIG. 3 is a partially sectional front view of the second separation device of the present invention. FIG. 4 is a diagram showing the correlation between specific gravity and the upward stroke of the impeller. 16: tank, 17a: upper space, 17b: lower space,
18, 19, 20: filter material layer, 22: wire mesh, 23: upper surface of wire mesh, 30: impeller, 36: blade, 37: lower surface of blade, 38: shear discharge pipe, 39: space, 41: filter bed layer , 42
: Pipe for draining muddy water, 52 Niji cylinder, 58: Hollow shaft.

Claims (1)

[Claims] 1. A sealable tank, and a filtering material layer disposed within the tank with a space left at least in the upper part of the tank;
A pipe for introducing high-pressure air into the upper space in the tank and a pipe for introducing muddy water, a driven rotation and an impeller having blades held at a distance above the filter layer, and the filter. A slot provided on the peripheral wall of the tank so as to communicate with the upper space at approximately the same level as the top surface of the filtering media layer, in order to discharge the slippery remaining on the filter material layer and moved by the impeller to the outside of the tank. a discharge pipe; a rotary valve provided on the shear discharge pipe to maintain high pressure in the upper space within the tank while discharging the liquid; A device for separating muddy water mixed with grinding, which is equipped with a muddy water discharge pipe for discharging the muddy water. 2. A sealable tank, and a filtering material layer disposed within the tank with a space left at least in the upper part of the tank;
A pipe for introducing high-pressure air and a pipe for introducing muddy water into the upper space of the tank, and a driven rotary impeller having blades held at intervals above the filtering material layer so as to be able to rise and fall; , provided on the peripheral wall of the tank so as to communicate with the upper space at approximately the same level as the upper surface of the filter layer, in order to discharge the pickpocket remaining on the filter layer and moved by the impeller out of the tank. a rotary valve provided in the shear discharge pipe for maintaining high pressure in the upper space of the tank while discharging the muddy water collected in the lower part of the tank; A device for separating mixed muddy water, which is equipped with a muddy water discharge pipe for discharging it outside the tank.