JP3207610B2 - Mud viscosity adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling the viscosity of mud used in a muddy method, and more particularly, to the viscosity of muddy water used suitably for civil engineering work for digging a ground by circulating mud. It relates to a preparation device.

[0002]

2. Description of the Related Art In civil engineering works employing underground continuous wall methods such as a mud shield method, a reverse circulation method, and a BW method, an excavated space is usually filled with a mud having a high specific gravity such as bentonite liquid, and the mud is filled with the mud. The muddy water method is used in which the work proceeds while holding down the wall with water pressure. In such a construction method, the viscosity of the mud filled in the space changes due to the influence of groundwater and excavated soil,
It is common to circulate the mud and re-adjust the viscosity of the mud returned from the space to a viscosity range suitable for use, and then use it again.

[0003]

By the way, regarding the re-adjustment of the viscosity of the mud returned by the above-mentioned method,
The returned mud is sampled and analyzed by human power, its viscosity is measured, and then it is determined whether it is in a proper range for use.If it is out of the proper range, the viscosity is adjusted to be within the proper range, Served for use. However,
In this way, if sampling, analysis and measurement are performed manually, measurement cannot be performed continuously, so that the viscosity of the mud used for circulating reuse cannot be sufficiently controlled, and the viscosity of the mud must also be adjusted. Since it is performed manually, there is a problem that it takes time to keep the viscosity range within an appropriate range and a small fluctuation range. In addition, since these operations are performed manually, labor costs are included in the construction costs, and as a result, there is a problem in that reduction of the construction costs is one of the factors that hinder the reduction.

The present invention has been made in view of the above circumstances, and an object of the present invention is to be able to mechanically measure the viscosity of the mud to be recirculated and to automatically adjust the viscosity of the mud based on the measurement result. It is an object of the present invention to provide an apparatus for adjusting viscosity of mud which can be performed.

[0005]

Means for Solving the Problems Claim 1 of the present invention
In the muddy viscosity adjusting device described, the muddy water for preparation is stored, and a supply pipe for supplying muddy water to the muddy water use point and a return pipe for introducing muddy water returned from the muddy water use point and the stored prepared muddy water are used. A preparation tank having a discharge pipe for discharging, a mud storage tank having an addition pipe for storing previously prepared high-viscosity muddy water and supplying the stored muddy water to the preparation tank; An excess mud tank containing muddy water discharged from the tank, a viscosity measuring device for measuring the viscosity of the muddy water in the preparation tank in the preparation tank, and a water level of the muddy water in the preparation tank. Providing a level detection device for detecting, providing an addition pump in the addition pipe, providing a discharge pump in the discharge pipe, the viscosity measuring device, the level detection device, the addition pump, between the discharge pump, Viscosity measurement device The operation of the addition pump is stopped when the measured viscosity is equal to or higher than a predetermined viscosity upper limit, and the discharge pump is operated when the viscosity is equal to or lower than a predetermined viscosity lower limit. When the detected water level is equal to or higher than a preset level upper limit value, the operation of the addition pump is stopped, and when the detected water level is equal to or lower than a preset level lower limit value, the addition pump is activated and the discharge pump is operated. Providing a pump controller for stopping the operation is a means for solving the above problem.

[0006] In the viscosity adjusting device for muddy water according to claim 2,
Instead of the mud storage tank, storing a low-viscosity muddy water or fresh water prepared in advance, a water storage tank having an addition pipe for supplying the stored muddy water to the preparation tank, further comprising a pump controller, When the viscosity measured by the viscosity measuring device is equal to or more than a preset viscosity upper limit, the discharge pump is operated, and when the viscosity is equal to or less than a preset viscosity lower limit, the operation of the addition pump is stopped. The operation of the addition pump is stopped when the water level detected by the level detection device is equal to or higher than a predetermined upper limit value, and the addition pump is operated when the water level is equal to or lower than a predetermined lower limit value. Stopping the operation of the discharge pump is a means for solving the above problem.

[0007]

In the viscosity adjusting device according to the first aspect of the present invention, the viscosity of the preparation mud in the preparation tank for storing the mud returned by the return pipe is mechanically measured by a viscosity measuring device. When the viscosity becomes equal to or less than the lower limit of viscosity set in advance, the discharge pump is operated by the pump controller, and the preparation mud in the preparation tank is discharged to the excess mud tank by the discharge pipe. If this discharge continues, the water level (level) of the preparation mud in the preparation tank drops, and finally reaches the preset level lower limit value. Then, the level detecting device detects that the level of the muddy water for preparation has reached the level lower limit, and the pump controller stops the operation of the discharge pump and activates the addition pump. When the addition pump is operated, the high-viscosity mud is added to the preparation tank by the addition pipe, and the viscosity of the preparation mud in the preparation tank gradually increases. Then, when the viscosity of the preparation mud in the preparation tank becomes equal to or higher than a predetermined upper limit, or equals or exceeds a predetermined level upper limit, the operation of the addition pump is stopped. In addition, during the period from when the addition of the muddy water is started by the addition pump and until it is further stopped,
When the value measured by the viscosity measuring device is equal to or less than the lower limit, the preparation mud is discharged by operating the discharge pump,
Thereby, the viscosity of the preparation mud in the preparation tank is set to be increased more rapidly in combination with the addition of the high viscosity mud from the addition pipe.

[0008] In the viscosity adjusting device for mud water according to claim 2,
The viscosity of the preparation mud in the preparation tank that stores the mud returned by the return pipe is mechanically measured by a viscosity measuring device,
When the measured viscosity is equal to or higher than the preset viscosity upper limit, the pump controller operates the discharge pump,
The mud for preparation in the preparation tank is discharged to an excess mud tank by a discharge pipe. When the discharge continues, the level of the preparation mud in the preparation tank drops as in the case of the apparatus of the first aspect, and reaches the preset level lower limit. Then, the level detecting device detects that the level of the muddy water for preparation has reached the level lower limit, and the pump controller stops the operation of the discharge pump and activates the addition pump. When the addition pump is operated, low-viscosity muddy water or fresh water is added to the preparation tank via the addition pipe, and the viscosity of the preparation muddy water in the preparation tank gradually decreases. Then, when the viscosity of the preparation mud in the preparation tank becomes equal to or less than a predetermined lower limit value or equals or exceeds a preset level upper limit value, the operation of the addition pump is stopped.

[0009]

FIG. 1 is a view showing an embodiment of a muddy viscosity adjusting device according to the present invention. In this figure, reference numeral 1 denotes a muddy viscosity adjusting device (hereinafter abbreviated as "preparing device"). This preparation device 1 is for adjusting the viscosity of mud circulated and used in the muddy water method within a range suitable for use. Specifically, a viscosity upper limit value and a viscosity lower limit value suitable for use are respectively set in advance. This is for adjusting the viscosity of the returned muddy water to a viscosity between the upper limit value and the lower limit value, and recirculating and supplying the same. In addition, this preparation device 1
The mud used for circulation is gradually diluted by groundwater,
It is suitable for use in excavation sites where viscosity tends to decrease.

The preparation apparatus 1 includes a preparation tank 2 for storing preparation mud, a storage tank 3 for storing high-viscosity mud, and an excess mud tank 4 for storing mud discharged from the preparation tank 2. It is provided. The preparation tank 2 includes a supply pipe 5 for supplying muddy water to the muddy water use point, a return pipe 6 for introducing return muddy water from the muddy water use point, and a discharge pipe 7 for discharging the stored preparation muddy water. And a stirrer 8 for homogenizing the preparation mud in the tank. The supply pipe 5 is provided with a delivery pump 9 for delivering the preparation mud from the preparation tank 2, and the discharge pipe 7 is provided with a discharge pump 10 for discharging the preparation mud from the preparation tank 2. I have. The preparation tank 2 also has a viscosity measuring device 11 for measuring the viscosity of the stored preparation mud,
A level detector 12 for detecting the level (level) of the preparation mud in the preparation tank 2 is provided. The viscosity measuring device 11 is of a known type in which the muddy water for preparation in the preparation tank 2 is automatically sampled at preset time intervals, and the viscosity is measured by flowing the sampled muddy water to a measuring section. It is. A pump controller is electrically connected to the viscosity measuring device 11 as described later, and the measured viscosity value is transmitted to the pump controller by an electric signal.

The level detecting device 12 has, for example, a float type sensor, and these are used to detect the position of the preset muddy water in the preparation tank 2 between the level upper limit value and the level lower limit value. , Respectively, and detects when the voltage becomes equal to or more than the level upper limit value and when the value becomes lower than the level lower limit value, and sends an electric signal to a pump controller described later. The mud storage tank 3 stores high-viscosity mud water, that is, mud water having a higher viscosity than the above-mentioned viscosity upper limit suitable for use. An addition pipe 13 for supplying the stored mud water to the preparation tank 2 is provided. And a stirrer 14 and a level detecting device 15. The addition pipe 13 is provided with an addition pump 16 for sending high-viscosity muddy water from the mud storage tank 3 to the preparation tank 2.

Further, a mud making facility 18 is connected to the mud storage tank 3 through an introduction pipe 17. This mud making equipment 18
A hopper 19 for storing bentonite powder and further putting it into a mud making tank to be described later, and a returning mud tank 20 for storing mud returned from the surplus mud tank 4 as described later.
It comprises a mud making tank 21 for mixing high-viscosity muddy water by mixing bentonite powder and muddy water sent from the hopper 19 and the returned muddy water tank 20, respectively. In the mud making tank 21, the high viscosity mud in the mud making tank 21 is stored in the mud storage tank 3.
The feed pipe 17 for feeding the high viscosity muddy water is provided in the feed pipe 17. The pump 22 lowers the level (level) of the highly viscous muddy water in the mud storage tank 3 to a level below a preset level, which is detected by the level detector 15, and sends a detection signal to a pump controller (not shown). As a result, the apparatus is configured to be operated by receiving a signal from the pump controller.

The excess muddy water tank 4 contains the muddy water discharged from the preparation tank 2 by the discharge pipe 7, has a stirrer 23, and further has a pipe 24 for sending the stored muddy water to the return muddy water tank 20. And a pipe 26 for sending to the secondary processing equipment 25. The pipes 24 and 26 are provided with pumps 27 and 28 for sending out muddy water, respectively. Further, the viscosity measuring device 11, the level detecting device 1
2. A pump controller 29 is electrically connected to each of the addition pump 16 and the discharge pump 10. The pump controller 29 stops the operation of the adding pump 16 when the viscosity measured by the viscosity measuring device 11 is equal to or higher than the preset viscosity upper limit value, and discharges when the viscosity is equal to or lower than the preset viscosity lower limit value. When the pump 10 is operated, and when the water level detected by the level detecting device 12 is equal to or higher than the preset level upper limit value, the operation of the addition pump 16 is stopped, and when the water level is equal to or lower than the preset level lower limit value. The operation of the addition pump 16 and the operation of the discharge pump are stopped.

Next, a method of circulating and using mud using such a preparation apparatus 1 will be described. When the viscosity of the muddy water to be circulated, that is, the viscosity of the muddy water for preparation in the preparation tank 2 is within a range suitable for use (between the upper limit value of viscosity and the lower limit value of viscosity), the pump 9 for preparation uses Send muddy water,
Further, the circulation by returning the muddy water from the return pipe 6 by a pump (not shown) is repeated. In this case, it is a matter of course that the viscosity of the preparation mud is automatically measured by the viscosity measuring device 11 at predetermined intervals. In addition, when the viscosity of the preparation mud drops due to circulating use, and the measured value becomes equal to or less than the viscosity lower limit set in advance by the viscosity measuring device 11,
A signal is sent to the pump controller 29, and a signal is sent from the pump controller 29 to operate the discharge pump 10. When the discharge pump 10 operates,
The mud for preparation in the preparation tank 2 is discharged to the surplus mud tank 4 by the discharge pipe 7, and if this discharge continues, the level of the mud for preparation in the preparation tank 2 decreases, and finally the level lower limit set in advance. Up to

When the level of the preparation mud falls below the level lower limit, the level is detected by the level detector 12,
The signal is sent to the pump controller 29. When a signal is further sent from the pump controller 29, the operation of the discharge pump 10 is stopped, and the addition pump 16 is operated. Addition pump 16
Is activated, the highly viscous mud in the storage tank 3 is added to the preparation tank 2 by the addition pipe 13, whereby the viscosity of the preparation mud in the preparation tank 2 gradually increases. When the viscosity of the preparation mud in the preparation tank 2 becomes equal to or higher than the preset upper limit value, or when the level of the preparation mud becomes equal to or higher than the preset level upper limit value, the operation of the addition pump 16 is stopped. Then, the addition of the highly viscous muddy water into the preparation tank 2 is stopped.

Accordingly, when the viscosity of the slurry for preparation becomes lower than the lower limit of the viscosity, the high viscosity mud is added immediately to increase the viscosity, and when the slurry reaches the upper limit of the viscosity, the addition is stopped and the viscosity is further increased. As a result, the viscosity is always adjusted and maintained suitable for use. In addition, even when the addition of the muddy water is started from the addition pump 16 and further stopped, if the value measured by the viscosity measurement device 19 is equal to or less than the lower limit, the preparation muddy water by the operation of the discharge pump 10 is operated. Is discharged, whereby the addition pipe 1 is discharged.
The viscosity rise of the preparation mud in the preparation tank 2 is further accelerated in combination with the addition of the high viscosity mud from Step 3. A part of the low-viscosity mud sent from the preparation tank 2 to the surplus mud tank 4 is returned through the pipe 24 by the operation of the pump 27.
The other part is sent to the secondary processing facility 25 through the pipe 26 by the operation of the pump 28.

In such a preparation device 1, the viscosity of the preparation mud is mechanically and automatically measured by the viscosity measurement device 11, and based on the measurement result, the viscosity of the mud is particularly reduced from the viscosity suitable for use. When the temperature is low, high viscosity mud is automatically added and supplied, so that parts that previously depended on human power were mechanized (automated) to save labor, and viscosity measurement and viscosity readjustment were performed. By automatically and mechanically performing the above, the viscosity change of the mud used for circulation can be reduced. In the above embodiment,
Although the example used suitably for the excavation site where the viscosity of the muddy water tends to decrease has been shown, the influence of the groundwater etc. is small, and even the excavation site where the viscosity of the muddy water tends to increase due to the earth and sand generated when excavating. The preparation apparatus of the present invention can be used.

As a preparation device used at an excavation site where the viscosity of muddy water tends to increase, a water storage tank is provided in place of the mud storage tank 3 shown in FIG. 1, and a pump controller 29 is measured by the viscosity measurement device 11. The discharge pump 10 may be operated when the viscosity is equal to or higher than the preset viscosity upper limit, and the operation of the addition pump 16 may be stopped when the viscosity is equal to or lower than the preset viscosity lower limit. As a water storage tank, fresh water is stored instead of muddy water,
Although it is the simplest mechanism to add to the mud, the mud from the surplus mud tank 4 may be diluted with fresh water and stored. In the case of using diluted muddy water obtained by diluting muddy water with fresh water, it is necessary to prepare the viscosity in advance so as to be lower than the viscosity lower limit suitable for use.

In such a preparation device, when the viscosity of the preparation mud becomes higher than the upper limit of the viscosity, the discharge pump 10
Is activated to discharge the preparation mud, and thereby the preparation tank 2
Level is less than the level lower limit. Then, the addition pump 16 is operated to add fresh water or low-viscosity mud from the water storage tank into the preparation tank 2, whereby the viscosity of the preparation mud is reduced to a proper viscosity. In the above-described example, an example in which the mud storage tank 3 is provided and an example in which the water storage tank is provided are shown. However, it is a matter of course that the apparatus may be provided with both of them. It may be provided and operated separately.

[0020]

As described above, the viscosity adjusting device of the present invention measures the viscosity of the mud for preparation mechanically and automatically by the viscosity measuring device, and uses the viscosity of the mud based on the measurement result. If the viscosity is out of the range, the muddy water or fresh water is automatically added and supplied to return to the range suitable for use. Therefore, the parts that previously depended on human power were mechanized (automated) to save labor. The construction cost can be reduced by the construction. In addition, since the viscosity change of the mud used for circulation can be reduced by mechanically and automatically performing the viscosity measurement and the re-adjustment of the viscosity, the viscosity of the circulated mud becomes higher than an appropriate range along with the excavation work, Alternatively, it is possible to prevent trouble from occurring in the muddy water transport equipment and the muddy water treatment equipment due to the lowering.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a viscosity adjusting device for muddy water according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Muddy viscosity adjusting device 2 Preparation tank 3 Mud storage tank 4 Excess muddy tank 5 Supply pipe 6 Return pipe 7 Discharge pipe 10 Discharge pump 11 Viscosity measuring device 12 Level detector 13 Addition pipe 16 Addition pump

Continuation of the front page (56) References JP-A-51-140335 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B28C 1/02 E21D 9/06 301

Claims (2)

(57) [Claims] An apparatus for adjusting the viscosity of mud used in circulation in a muddy method, which stores muddy water for preparation, and supplies a muddy water to a muddy water use point and returns the muddy water from the muddy water use point. A preparation tank having a return pipe for introducing the muddy water and a discharge pipe for discharging the stored prepared muddy water, storing the previously prepared high-viscosity muddy water, and supplying the stored muddy water to the above-mentioned preparing tubing And a surplus mud tank containing mud discharged from the preparation tank, wherein the viscosity of the preparation mud is measured in the preparation tank. An apparatus and a level detection device for detecting the level of the muddy water for preparation in the preparation tank; an addition pump provided in the addition pipe; a discharge pump provided in the discharge pipe; Equipment for addition When the viscosity measured by the viscosity measuring device is equal to or higher than the preset viscosity upper limit, the operation of the addition pump is stopped between the pump and the discharge pump, and the viscosity is equal to or lower than the preset viscosity lower limit. When the discharge pump is operated, when the water level detected by the level detection device is equal to or higher than a predetermined level upper limit value, the operation of the addition pump is stopped, and when the water level is equal to or lower than a predetermined level lower limit value. A viscosity controller for muddy water, comprising a pump controller for operating the addition pump and stopping the operation of the discharge pump. 2. An apparatus for adjusting the viscosity of mud used in circulation in a muddy construction method, wherein the muddy water for preparation is stored, and a supply pipe for supplying muddy water to the muddy water use point and returned from the muddy water use point. A preparation tank having a return pipe for introducing muddy water and a discharge pipe for discharging the stored prepared muddy water, and storing low-viscosity muddy water or fresh water prepared in advance, and storing the stored muddy water in the preparation tank. A water tank having an addition pipe for supplying, and an excess mud tank containing muddy water discharged from the preparation tank, wherein the viscosity of the preparation tank for measuring the viscosity of the preparation mud in the preparation tank is provided. A measuring device, and a level detecting device for detecting a level of muddy water in the preparation tank, a adding pump in the adding tube, a discharging pump in the discharging tube, a viscosity measuring device, detection Between the device, the addition pump, the discharge pump, when the viscosity measured by the viscosity measuring device is equal to or higher than a predetermined viscosity upper limit, the discharge pump is operated, and the viscosity is set to a predetermined viscosity lower limit or lower. When the operation of the addition pump is stopped, the operation of the addition pump is stopped when the water level detected by the level detection device is equal to or more than a predetermined level upper limit, and the predetermined level lower limit is set. A viscosity controller for muddy water, comprising a pump controller for operating the addition pump and stopping the operation of the discharge pump when the following conditions are satisfied.