JPH02178497A - Deaeration processing method for bubble-mixed muck - Google Patents

Abstract

PURPOSE:To surely perform deaeration at a low cost by applying the deaeration process to the excavation muck mixed with bubbles in a discharge facility and discharging the deaerated excavation muck under the atmospheric pressure behind a bulkhead. CONSTITUTION:A cutter head 5 arranged with an injection pipe 9 injecting bubbles is provided in front of an earth pressure type shield excavator 1 and a bulkhead 7 suppressing the working place earth pressure at the rear respectively to form an earth pressure chamber 8. A decompressor 16 storing the bubble- mixed muck discharged from a screw conveyor 13 is arranged between the discharge port of a rotary feeder 15 and the end section of the receiving side of a belt conveyor 18. Bubbles are mixed into excavation muck through the cutter head 5, the cutting resistance of a cutter bit 12 is decreased, and the bubble-mixed muck is discharged via the screw conveyor 13 and carried into the decompressor 16. The bubble-mixed muck is decompressed in the decompressor 16, and bubbles are deaerated.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a method for degassing shear containing air bubbles, and more specifically, to a method for reducing cutting resistance between a face ground surface and a cutter focus during excavation by a shield excavator. Alternatively, the present invention relates to a deaeration treatment method for removing air bubbles from excavated slag mixed with air bubbles supplied in order to improve the fluidity and watertightness of the slag.

[Conventional technology]

When excavating with an earth pressure type shield excavator, a liquid containing a foaming agent is injected in front of the bulkhead of the shield excavator in order to reduce the cutting resistance between the face ground surface and the cutter pin, or to increase fluidity and water sealing properties against excavation shear. Alternatively, a method has been adopted in which air bubbles are directly injected into the excavated slag.

Conventionally, a bubble-mixing pickpocket is discharged from a discharge facility from pressurized pressure in front of a partition wall to atmospheric pressure in the rear, without causing face collapse due to a pressure drop while maintaining the pressurizing force in front of the partition wall at a predetermined pressure. It was transported to a dumping ground.

However, it takes a long time for the air bubbles to escape from the air-filled shear accumulated at the soil dump. In addition, depending on the soil quality, air bubbles may not be degassed and may exist in the slats, resulting in the formation of soft ground that is difficult to improve.

In order to improve these problems, conventional methods have been used to eliminate air bubbles in the slurry by leaving the bubbles in the slurry in a natural state, or by adding an antifoaming agent to the bubbles and stirring and mixing. It has been taken. (For example, JP-A No. 63-134790) [Problem to be solved by the invention] By the way, the method of leaving air-filled shear in a natural state takes a long time and requires a large area for treatment, making it uneconomical. There were many problems such as the air bubbles not escaping depending on the soil type.

The method of adding an antifoaming agent to the air-containing soil and mixing it with stirring may require a large amount of antifoaming agent depending on the soil type, making it uneconomical, or it is often impossible to perform antifoaming treatment on cohesive soil. Ta.

The object of this invention was to solve the above-mentioned problems, and to provide a complete deaeration treatment for the entire soil, and to make the deaeration treatment economical, without air bubbles mixed in with shear. An object of the present invention is to provide a deaeration treatment method.

[Means to solve the problem]

In order to solve the above-mentioned problems, the first invention uses a foaming agent foaming method or direct injection in order to reduce the cutting resistance between the face ground surface and the cutter bit, or to improve fluidity and water sealing properties against excavation shears. Excavation waste containing air bubbles injected by the method is degassed by reducing the pressure with a decompression device in the discharge facility that communicates with the front of the bulkhead behind the bulkhead of the shield machine. The construction is such that each excavation is discharged by the discharge facility under atmospheric pressure behind the bulkhead while maintaining the pressurizing force in front of the bulkhead at a predetermined pressure.

In addition, the second invention is a method in which air bubbles injected by a foaming agent foaming method or a direct injection method are mixed in order to reduce the cutting resistance between the face ground surface and the cutter bit or to improve fluidity and water stoppage against excavation shear. The excavated shear is discharged through the discharge facility behind the bulkhead while maintaining the pressure in front of the bulkhead of the shield machine at a predetermined pressure, and the air bubbles are degassed by reducing the pressure of the discharged air bubbles in the decompression device. It is configured to do so.

[Effect]

During excavation by an earth pressure type shield excavator, air bubbles are mixed into the excavated shear in order to reduce the cutting resistance between the face ground surface and the cutter bit, or to increase the fluidity and water sealing properties against the excavated shear.

The excavated slurry with air bubbles mixed in it is subjected to deaeration treatment in a pressure reducing device within the discharge facility or under atmospheric pressure after discharge, and the air bubbles mixed in are removed.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 to 3 show different examples of deaeration of shear mixed with air bubbles in the discharge facility of an earth pressure type shield excavator.

First, in the example shown in Figure 1, earth pressure type shield excavation J
The f11 is equipped with a shield jack 3 at the rear of the shield body 2 that excavates the shield body 2 by taking a reaction force against the segment 4, and a rotary cutter head 5 that cuts the face ground 6 at the front. A partition wall 7 is provided on one side to support the rotary cutter head 5 and to suppress earth pressure at the face, thereby forming an earth pressure chamber 8.

The cutter head 5 is equipped with an injection pipe S for injecting air bubbles into the face ground 6, and the partition wall 7 is provided with an injection pipe 10 for supplying air bubbles to the excavated debris taken into the soil shovel chamber 8. There is. Further, a scraping plate 11 is attached to the back surface of the cutter head 5 to scrape up excavated debris within the earth pressure chamber 8.

According to the above-mentioned Tonosho type shield excavation [1, face ground 6
By the action of the air bubbles supplied to the cutter from the hood 5, the cutting resistance of the cutter bit 12 attached to the cutter head 5 is reduced, and the excavator has improved fluidity and water-stopping properties, and is able to resist the face earth pressure. However, it has the feature that it can be discharged from the screw conveyor 13.

A slide gate 14 and a rotary feeder 15 are connected to the screw conveyor 13, and a reduced pressure is provided between the discharge port of the rotary feeder 15 and the receiving end of the belt conveyor 18 to store the air-filled shear discharged from the screw conveyor 13. A device 16 is arranged.

As the pressure is reduced, the volume of the air bubbles entering this decompression device 16 increases in proportion to the pressure, and when the interfacial tension of the air bubbles is exceeded, the bubbles break, and from the air bubbles Air bubbles are degassed.

The deaerated excavation slide is conveyed from the slide gate 17 of the decompression device 16 to a shear truck (not shown) by a belt conveyor 18, and is carried out of the mine.

Next, in the example shown in FIG. 2, the pressure reducing device 16 is incorporated into a sliding trolley 19.

In the example shown in FIG. 2, the structure for discharging the air-filled shear to the slide gate 14 provided on the screw conveyor 13 is similar to that of the example shown in FIG. The bubble-mixed pickle discharged from the slide gate 14 is carried by a belt conveyor 18 onto a picket truck 19 equipped with a pressure reducing device.

The pick-up truck 1S with the pressure reducing device is a battery car (
While the shear is being towed to the excavation shaft (not shown) by the excavated shear (not shown), air bubbles are degassed from the air-filled shear by the decompression device 16, and the deaerated shear is carried out of the mine. .

In the example shown in FIG. 3, the pressure reducing device 16 is provided on the screw conveyor 27.

In the example shown in FIG. 3, the treatment of air bubbles up to the earth pressure chamber 8 surrounded by the partition wall 7 has the same structure as the example shown in FIG. is similar to the structure proposed by one of the present applicants in Japanese Patent Application Laid-open No. 134790/1983, and the screw conveyor 27 for discharging the bubble-containing shear coming out from the soil storage chamber 8 has a spherical screw part 33. A member 21 is attached, and by moving the screw portion 33 back and forth between the funnel-shaped portions 20, the amount of discharged shear mixed with air bubbles and the predetermined pressure under pressurization can be easily adjusted.

When a predetermined amount of shear mixed with air bubbles is taken into the rear of the funnel-shaped part 20, the screw part 33 to which the spherical member 21 is attached is moved forward, and the section from the rear of the funnel-shaped part 20 to the slide gate 26 is moved forward. The pressure reducing device 16 is sealed and attached to the screw conveyor 27.
This process deaerates the air bubbles trapped in that section.

The degassed excavated shear is conveyed from the slide gate 26 through the belt conveyor 18 to a shear truck (not shown) and carried out of the mine.

A slide gate 25 is attached to the screw conveyor 27 in front of the funnel-shaped part 20, so that troubles caused by sudden changes in the ground when the screw part 33 with the spherical member 21 is moved backward can be dealt with.

In the example shown in Figure 4, the deaeration process for the bubble-containing shear is carried out at the part discharged from the discharge facility to atmospheric pressure. The drawing shows a case where the decompression device 16 is placed on the ground.

In FIG. 4, the structure up to the heald conveyor 18 shown in FIG. 2 is the same as that in the example shown in FIG. The bubble-containing slide is transported to the shaft by a general pick-up truck 28, and only the loading platform 30 of the pick-up truck 28 is suspended by a portal crane 29, and the bubble-containing slide is collected in a decompression device 16 for degassing. . The treated excavation material is transferred from the hopper portion 32 to a dump truck (not shown) and transported to a dump site.

In addition, in any of the above examples, the pressure reducing device 16 is
In addition to simply reducing the pressure, vibration or stirring may be used, or a compression device may be used to reduce the pressure and degas the air bubbles while compressing the shear.

Further, in the depressurization process, degassing can also be performed by suddenly discharging the excavated debris from the compression device to atmospheric pressure.

[Effects of the Invention] As described above, according to the present invention, the air bubbles generated during excavation by the earth pressure shield excavator are degassed by reducing the pressure with the decompression device. can be done reliably and at low cost,
It is possible to improve economic efficiency.

In addition, deaeration by depressurization can reliably remove air bubbles in the excavation slide, and it is possible to perform complete deaeration treatment for all soil types, with no difference in the degree of deaeration treatment depending on the soil type. The deaerated pickpockets will accumulate.

[Brief explanation of the drawing]

Each of FIGS. 1 to 4 is a longitudinal sectional view showing different examples of a deaeration processing apparatus for carrying out the deaeration processing method according to the present invention. 1...Earth pressure type sole excavator, 5...
Throat to rotating cutter, 6... Face ground, 7... Bulkhead,
8...Earth pressure chamber, 13.2? ...screw conveyor, 16...
...R pressure "A'fl, 18... Heltconhair, 19.28...fsu) Ronco. Patent applicant: Osaka Soil Testing Institute, Manuma Gumi Co., Ltd. Kawasaki Heavy Industries, Ltd. Agent Aya Kamata Figure 1 Figure 2 154 Figure 3

Claims (2)

[Claims] (1) In order to reduce the cutting resistance between the face ground surface and the cutter bit, or to increase the fluidity and water-stopping properties against excavation shear, the excavated slag is mixed with air bubbles injected using a foaming agent foaming method or direct injection method. On the other hand, in the discharge facility behind the bulkhead of the shield machine that communicates with the front of the bulkhead, deaeration is performed by reducing the pressure with a decompression device, and the deaerated excavated slag is applied to the front of the bulkhead to a predetermined pressure. A method for degassing shear containing air bubbles, in which the shear is discharged under atmospheric pressure behind the partition wall by the discharge facility. (2) In order to reduce the cutting resistance between the face ground surface and the cutter bit, or to improve the fluidity and water stoppage against excavation shear, excavation debris mixed with air bubbles injected by foaming agent foaming method or direct injection method is used. , while maintaining the pressurizing force in front of the bulkhead of the shield machine at a predetermined pressure, it is discharged by the discharge facility behind the bulkhead, and the discharged bubble-containing shear is depressurized in a decompression device to degas the bubbles. Deaeration treatment method.