JPH07106286B2 - Muddy water treatment system in shield method - Google Patents

Description

The present invention relates to a low noise muddy water treatment system in a shield construction method.

(Prior Art) In the muddy water pressure shield method, muddy water having a concentration, a specific gravity and a viscosity necessary for stabilizing the face of the excavator and preventing collapse of the face is supplied under pressure to the excavator. Since the muddy water is circulated and deteriorated due to mixing of the excavated soil, a muddy water treatment system for removing the excavated soil from the muddy water and reusing the specific gravity of the muddy water as an appropriate one is installed.

In a conventional muddy water treatment system, a vibrating screen is used to separate the excavated soil carried out together with the muddy water from the excavator, and the specific gravity of the settling tank and the muddy water that separate the muddy water from the vibrating screen are settled and separated. It was composed of a specific gravity adjusting tank and so on.

(Problems to be Solved by the Invention) However, according to the above-mentioned known shield construction method, since the vibrating sieve is provided, noise due to vibration is large, and the construction in the residential area or at night is restricted.

Further, in the above-mentioned conventional muddy water treatment system, when the amount of fine sand accumulated in the sedimentation tank reaches a certain amount or more, the supernatant water is discharged from the sedimentation tank, dried for several days in the sun, and then manually discharged to the outside. However, there was a problem of poor work efficiency.

An object of the present invention is to provide a muddy water treatment system which has low noise and can efficiently discharge fine sand deposited in a sedimentation tank.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a sedimentation portion in which mud water mixed with excavated soil discharged from an excavator is introduced to sediment the sediment, and sediment deposited in the sedimentation portion. A sedimentation type classifier equipped with a continuous discharge mechanism that continuously discharges, and a sedimentation tank in which mud water discharged from the sedimentation type classifier is introduced to precipitate fine sand is arranged. A fine sand discharging mechanism for discharging the settled fine sand is provided and configured.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

Referring to FIG. 1, in the muddy water pressure type shield construction method, muddy water containing clay such as bentonite is pressurized and supplied to a not-shown face of the excavator 1 to counteract groundwater pressure and prevent the face from collapsing. ing. In order to keep the muddy water in good condition, the following muddy water treatment system is installed.

A sedimentation type classifier for separating excavated soil from the muddy water discharged from the excavator 1 is installed. The settling type classifier 2 is provided with a settling section for putting mud water containing excavated soil carried out from the excavator 1 to settle the sediment and a continuous discharge mechanism for continuously discharging the settled sediment. Although a drum type classifier is exemplified in the present embodiment as the settling type classifier 1, a belt classifier having a belt conveyor as a continuous discharge mechanism, a spiral classifier having a spiral conveyor as a continuous discharge mechanism, and other classifiers Good.

In this drum type classifier, muddy water is introduced from an inlet 4 provided at one end surface of a rotating drum 3 which is a sedimentation part, and sediment is separated in the rotating drum 3 to separate the sediment from the muddy water and to be sedimented. The earth and sand are spiral blades 5 provided on the inner wall of the rotating drum 3.
Is brought to the other end surface of the rotary drum 3 by the
It is lifted up by and is discharged to the clay cleaning device 8 from the earth and sand discharge port 7. On the other hand, the muddy water from which the sediment has been separated overflows from the inlet 4 of the rotary drum 3 and is supplied to the precipitation tank 9.

Referring also to FIG. 2, the clay cleaning device 8 is a belt conveyor.
The conveyor belt of the belt conveyor 10 is arranged so that the starting end of the belt conveyor 10 is directed to the precipitation tank 9 and the end thereof is inclined upward.
11, a side skirt 12 is narrowed in a V shape so that the sediment becomes higher in the center of the conveying direction, a washing shower 13 that sprays washing water on the sediment, and a conveyor belt 11 vibrates. A vibration exciter 14 for dewatering is provided. The clay separated from the sediment is transported along with the cleaning water by the conveyor belt.
It flows down 11, is collected in the settling tank 9, and the earth and sand is discharged from the end of the belt conveyor 10 as it is. The side skirt 12 is provided with a turnbuckle 15 that changes the width to adjust the height of the earth and sand. The side skirt 12 enhances the dehydration effect and the cleaning effect.

In the settling tank 9, the residual fine sand in the muddy water is settled and separated,
The supernatant muddy water flows into the specific gravity adjusting tank 15.

Further, a traveling crane 17 for moving a rail 16 provided on the sedimentation tank 9 is arranged, and a traveling sand pump 18 for sucking the precipitated fine sand is suspended as a fine sand discharging mechanism on the traveling crane 17. . The excavator 1 repeats excavation and stop such that it stops after excavating for a certain time and performs the next setup, but while the excavator is stopped and the sedimentation type classifier 2 is not supplied with muddy water from the excavator 1, The moving sand pump 18 sucks the fine sand that has settled to the bottom of the settling tank 9, and throws it into the sedimentation type classifier 2 together with mud water. Since the amount of fine sand and muddy water fed from the moving sand pump 18 is small, the compact sedimentation type classifier 2 can sufficiently separate fine sand.

As the fine sand discharging mechanism for discharging the fine sand of the sedimentation tank, various mechanisms such as a moving sand pump, a mechanism for scraping out fine sand by a spiral mechanism or a rake mechanism, or a mechanism for discharging by a belt conveyor can be adopted. Is.

The clay and water are stirred in the mud making tank 19 to create mud, which is added to the specific gravity adjusting tank 15 to adjust the specific gravity of the mud, and then fed to the excavator by the circulation pump 20.

The present embodiment configured as described above operates as follows.

The mud mixed with the excavated soil carried out from the excavator 1 is fed to the sedimentation type classifier 2, and the sediment is settled in the rotary drum 3 to separate the sediment from the mud. The muddy water from which the sediment has been separated overflows from the input port 4 and is fed to the settling tank 9. Further, earth and sand are discharged from the earth and sand discharge port 7 of the settling type classifier 2 to the clay cleaning device 8, and the earth and sand are conveyed to the center in the conveying direction by the side skirts 12 so as to be raised and conveyed, and the shaker 14 is applied to the earth and sand.
Is shaken and the washing water is sprayed from the washing shower 13 to separate the clay from the earth and sand. The clay flows down the conveyor belt 12 together with the washing water and is collected in the precipitation tank 9. On the other hand, the earth and sand is discharged as it is from the end of the belt conveyor 10.

In the settling tank 9, fine sand in the muddy water is settled, and the clear muddy water is fed to the specific gravity adjusting tank 15. The excavator 1 stops when it excavates for a certain time and repeats excavation and stop such that the next setup is performed, but the excavator 1 stops intermittently and the muddy water is fed from the excavator 1 to the sedimentation type classifier 2. While there is not, the fine sand precipitated by the moving sand pump 18 which is moved by the traveling crane 17 in the settling tank 9 is fed to the settling type classifier 2 together with the muddy water. Since the amount of fine sand and muddy water input from the moving sand pump 18 is small, the compact sedimentation type classifier 2 can sufficiently separate fine sand, and the fine sand discharged from the sedimentation type classifier 2 is the above-mentioned earth and sand. Clay cleaning device 8
The clay is separated by and discharged.

The supernatant muddy water of the sedimentation tank 9 is fed to the specific gravity adjusting tank 15, and the muddy water created by stirring clay and water in the mud making tank 19 is added to the specific gravity adjusting tank 15 to adjust the specific gravity, and then the circulation pump. It is fed to the excavator 1 by 20.

(Effects of the Invention) In the present invention, since the fine sand that has settled to the bottom of the settling tank can be efficiently discharged by the fine sand discharging mechanism, the workability of the construction by the shield construction method is significantly improved.

Moreover, since a sedimentation type classifier is used, the noise is low.

[Brief description of drawings]

FIG. 1 is a system diagram of a muddy water treatment system according to an embodiment of the present invention. FIG. 2 is a plan view of the clay cleaning device. 1: Excavator, 2: Sedimentation type classifier, 3: Rotating drum, 4: Input port,
5: spiral blade, 9: sedimentation tank, 17: traveling crane, 18: moving sand pump

Claims (1)

[Claims] 1. In a muddy water treatment system in a shield construction method in which excavation is performed while injecting water, the excavated soil generated by the excavation is taken out together with the water, and solid-liquid separation is performed to circulate the water, the excavation carried out from the excavator. A settling type classifier equipped with a settling section for injecting mud water containing soil to settle the sediment and a continuous discharging mechanism for continuously discharging the settling sediment is discharged from the settling type classifier. A muddy water treatment system in a shield construction method, in which a settling tank for arranging the deposited muddy water to settle the fine sand is disposed, and a fine sand discharging mechanism for discharging the settled fine sand is provided in the settling tank.