JP5507411B2 - Bubble injection system - Google Patents

Description

  The present invention relates to a bubble injection system.

  In the bubble shield method, the foam is injected into the face of the face or shield machine and mixed with the foam and excavated earth and sand, ensuring the stability of the face against the face pressure and the flow of the excavated earth and sand. This improves the ability to carry out the excavated sediment.

  In such a bubble shield construction method, a foam injection system provided with a foaming device provided behind the bulkhead of the shield excavator, and a foaming material injection pump and a compressor connected to the foaming device via independent lines, respectively. It is common to inject a foam (see, for example, Patent Document 1).

JP 2006-214189 A

In the conventional bubble injection system, foaming material and compressed air, which are pumped through independent lines, are mixed by a foaming device and injected into a chamber as a shaving cream-like foam. Body injection pressure was generally determined by compressor capacity.
Therefore, under high water pressure conditions exceeding the discharge pressure of the compressor, there are cases where injection cannot be performed due to insufficient pressure.

  In addition, the adjustment of the injection flow requires time and effort because it is necessary to adjust the flow rate of the foaming material by the number of rotations of the foaming material supply pump and the flow rate of the compressed air by the opening of the compressor air valve. It was.

  The present invention has been made to solve such problems, and it is possible to inject even under high water pressure conditions, and to easily adjust the injection flow rate and the injection pressure. The problem is to provide a system.

  In order to solve the above problems, the present invention is a bubble injection system for injecting foam into a face or a chamber, and includes a foaming material supply pump, a compressor, a squeeze pump, and a foam cylinder. The squeeze pump pressurizes a mixture obtained by mixing the foaming material pumped through the foaming material supply pump and the compressed air pumped through the compressor, and pressurizes the pressurized mixture. It is characterized by being delivered to a foam cylinder.

According to such a bubble injection system, it is possible to perform bubble injection even under high water pressure by pressurization of a squeeze pump.
Also, the injection pressure can be easily adjusted by controlling the squeeze pump.
Furthermore, by keeping the injection speed by the squeeze pump constant, it is possible to perform injection in a fixed amount, and thus the injection flow rate can be easily controlled.

  In addition, the bubble injection system of the present invention includes a pressure sensor in the vicinity of the discharge port of the foamed cylinder, and controls the squeeze pump according to the earth pressure in the chamber and the pressure value measured by the pressure sensor. You may do.

  According to such a bubble injection system, it is possible to easily adjust the injection pressure and the injection flow rate according to the variation of the pressure.

  According to the bubble injection system of the present invention, injection is possible even under high water pressure conditions, and the injection flow rate and injection pressure can be easily adjusted.

It is a piping system diagram showing a bubble injection system according to an embodiment of the present invention. It is a piping system diagram which shows a part of bubble injection system of FIG. It is a block diagram which shows the control means of a bubble injection system.

The bubble injection system 1 of this embodiment is used in a bubble shield method, and injects a foam into the face of a face or an excavator chamber.
The bubble system 1 mixes a foaming material, compressed air, etc., produces | generates a foam, and inject | throws-in in the state which pressurized this foam.

  The bubble system 1 of this embodiment is provided with the foaming material supply pump 2, the compressor 3, the squeeze pump 4, and the foaming cylinder 5, as shown in FIG.

The bubble system 1 is provided with a plurality (eight in this embodiment) of injection systems, and the foaming material supply pump 2, the squeeze pump 4, and the foaming cylinder 5 are arranged in each of the injection systems.
That is, the bubble injection system 1 injects foam from a plurality of locations into the face or chamber through a plurality (eight in this embodiment) of squeeze pumps 4, 4,. In addition, the number of injection | pouring locations is not limited, What is necessary is just to set suitably according to excavation cross-sectional shape etc.

As shown in FIG. 2, the foaming material supply pump 2 is connected to the squeeze pump 4 via the foaming material pipe 21 and supplies the foaming material to the squeeze pump 4.
In the present embodiment, one foaming material supply pump 2 (8 units in total) is arranged for one squeeze pump 4.

A flow meter 22 is installed in the foaming material pipe 21 and is configured to be able to measure the flow rate of the foaming material supplied from the foaming material supply pump 2.
The foaming material pipe 21 is connected to a merging pipe 43 provided at the suction port of the squeeze pump 4. The foaming material supplied via the foaming material pipe 21 is sucked into the squeeze pump 4 in a state where it is mixed with compressed air in the merge pipe 43.

  In the foaming material, the liquid A and the liquid B supplied to the foaming material supply pump 2 are mixed and pressurized in the foaming material supply pump 2 to the pumping tube of the squeeze pump 4. Supplied.

As shown in FIG. 1, the A liquid is supplied from the A liquid tank 6 to the foaming material supply pump 2 via the A liquid supply pipe 61.
The A liquid tank 6 is disposed in the excavator or in the tunnel mine, and stores the A liquid conveyed via the transport vehicle 63 that travels in the tunnel mine. Reference numeral 63 a is a transfer pump that transfers the A liquid from the transport vehicle 63 to the A liquid tank 6.
The arrangement of the A liquid tank 6 is not limited to the inside of the excavator or the tunnel mine, but may be arranged outside the tunnel mine such as the ground part or the vertical shaft.

In the present embodiment, a liquid A supply pipe 61 connected to the foaming material supply pump 2 is piped for each foaming material supply pump 2. That is, the same number of A liquid supply pipes 61 as the number of foaming material supply pumps 2 are connected to the A liquid tank 6.
In addition, it is good also as a structure which employ | adopts a branch pipe as the A liquid supply pipe | tube 61, and supplies A liquid to each foaming material supply pump 2. FIG.

  Each A liquid supply pipe 61 is provided with an A liquid addition pump 62 so that the A liquid can be pumped from the A liquid tank 6 to the foaming material supply pump 2. In this embodiment, the liquid A addition pump 62 is disposed in the vicinity of the foaming material supply pump 2, but the liquid A addition pump 62 may be disposed between the foaming material supply pump 2 and the liquid A tank 6. It is not limited as long as it is arranged.

As shown in FIG. 2, a pressure gauge 64, a flow meter 65, and a back pressure valve 66 are disposed between the liquid A addition pump 62 and the foaming material supply pump 2. The A liquid addition pump 62 is controlled according to the pressure and flow rate of the A liquid measured by the pressure gauge 64 and the flow meter 65. The A liquid pressure-fed by the A-liquid addition pump 62 is controlled in the pressure variation by the back pressure valve 66 and is sent to the foaming material supply pump 2 at a constant pressure.
Reference numeral 67 denotes a filter for removing impurities in the liquid A.

  As shown in FIG. 2, the A liquid supply pipe 61 is connected to the B liquid supply pipe 71 in front of the foaming material supply pump 2. The A liquid supply pipe 61 and the B liquid supply pipe 71 are joined together, so that the A liquid is supplied to the foaming material supply pump 2 in a state of being mixed with the B liquid (foaming material).

  The B liquid is supplied from the B liquid tank 7 to the foaming material supply pump 2 via the B liquid supply pipe 71 as shown in FIG.

  The B liquid supply pipe 71 includes a single main pipe 71a connected to the B liquid tank 7, and branch pipes 71b, 71b,... Branched from the main pipe 71a and connected to the foaming material supply pumps 2. Has been.

A B liquid addition pump 72 is disposed in the main pipe 71a, and is configured to pump the B liquid in the B liquid tank 7 in the direction of each foaming material supply pump 2.
The B liquid pumped by the B liquid addition pump 72 is evenly supplied to each foaming material supply pump 2 via each branch pipe 71b.

B liquid is comprised by mixing clean water and B type material (stock solution of B liquid).
Mixing of the fresh water and the B type material is performed by the B liquid mixer 73.
In addition, B liquid may be only fresh water.

The B liquid mixer 73 stirs and mixes the fresh water supplied from the water storage tank 74 and the B type material supplied from the B type material tank 75.
In this embodiment, tap water is used as the fresh water, but the fresh water is not limited. Reference numeral 74 a is a submersible pump that supplies fresh water from the water storage tank 74 to the B liquid mixer 73. The submersible pump 74a is controlled according to the measured value of the flow meter 74b.

  The B type material is transported from the wellhead to the vicinity of the B type material tank 75 by the transport vehicle 76, and then transferred to the B type material tank 75 via the transfer pump 76a and stored.

  The B type material stored in the B type material tank 75 is supplied to the B liquid mixer 73 via the pump 75a. At this time, the pump 75a is controlled according to the measured value of the flow meter 75b.

  In the present embodiment, the B liquid tank 7, the water tank 74 and the B type material tank 75 are arranged in the excavator or the tunnel mine, but the arrangement of the B liquid tank 7, the water tank 74 and the B type material tank 75 is limited. However, it may be arranged outside the tunnel mine such as the ground part or in the shaft.

The compressor 3 supplies compressed air to the squeeze pump 4.
In this embodiment, although the compressor 3 is arrange | positioned in an excavator or a tunnel mine, arrangement | positioning of a compressor is not limited.

As shown in FIG. 1, the compressor 3 is connected to the squeeze pumps 4, 4,.
The air supply pipe 31 includes a main pipe 31a connected to the compressor 3 and branch pipes 31b, 31b,... Branched from the main pipe 31a and connected to the squeeze pumps 4.

  The branch pipe 31b is provided with an electromagnetic valve 32 for adjusting the flow rate of the compressed air, a regulator 33 for adjusting the pressure of the compressed air, and an air filter 34 for removing impurities from the compressed air.

As shown in FIG. 2, the air supply pipe 31 (branch pipe 31 b) is connected to a merging pipe 43 disposed at the suction port of the squeeze pump 4.
In the merging pipe 43, the foaming material pumped through the foaming material supply pump 2 and the compressed air pumped through the compressor 3 are mixed. The mixture thus obtained is supplied to the squeeze pump 4.

  The squeeze pump 4 pressurizes the mixture of foaming material and compressed air and sends the pressurized mixture to the foam cylinder 5.

As shown in FIG. 2, a mixture transport pipe 41 connected to the foam cylinder 5 is piped at the discharge port of the squeeze pump 4.
A pressure gauge 42 is installed at a connection portion between the discharge port of the squeeze pump 4 and the mixture transport pipe 41. The pressure gauge 42 measures the pressure of the mixture discharged from the squeeze pump 4.

The foam cylinder 5 generates a foam by passing the mixture fed through the squeeze pump 4.
As shown in FIG. 2, a flow meter 51 is installed in the foam cylinder 5. The flow meter 51 measures the flow rate of the mixture passing through the foamed cylinder 5.

The foam discharged from the foam cylinder 5 is injected into the face or chamber through the injection pipe 52.
A flow meter 53 and a pressure sensor 54 are installed at a connection portion between the discharge port of the foaming cylinder 5 and the injection pipe 52. The flow meter 53 measures the flow rate of the foam injected into the face or chamber, and the pressure sensor 54 measures the pressure of the foam.

  As shown in FIG. 1, in this embodiment, a pressure sensor 8 is disposed on the cutter head so that the earth pressure in the chamber can be measured. Note that the installation location of the pressure sensor 8 is not limited as long as the earth pressure in the chamber can be measured, and may be installed, for example, in a bulkhead.

  The foam injection amount and the injection pressure are controlled by the earth pressure in the chamber measured by the pressure sensor 8 and the measurement values of the foam injection amount and injection pressure measured by the flow meter 53 and the pressure sensor 54. Accordingly, the squeeze pump 4 is controlled.

In the present embodiment, control of the squeeze pump 4 and the like is executed by the control means 9.
As shown in FIG. 3, the control means 9 includes an operation panel 91, a sensor management panel 92, a CPU box 93, a plurality of pump management panels 94, 94,. Yes.

The operation panel 91 includes a start switch for the bubble injection system 1, an injection system selection switch, and the like.
A signal output from the operation panel 91 is transmitted to the CPU box 93.

  The sensor management panel 92 converts each data measured by each measuring instrument such as the pressure sensors 8 and 54 and the flow meter 53 into a signal and transmits it to the CPU box 93.

The CPU box 93 responds to the signal transmitted from the operation panel 91 and the data of each measuring instrument such as the pressure sensors 8 and 54 and the flow meter 53 input via the sensor management panel 92. A signal is output to the liquid management board 95 to control the injection pressure and the injection flow rate.
That is, in the bubble injection system 1, the CPU box 93 outputs a signal in accordance with the data measured by each measuring instrument, the excavation speed, the excavation cross-sectional area, etc., and controls the number of revolutions of the squeeze pump 4 and the like. The body pressure and flow rate are controlled.

  The pump management panel 94 controls the squeeze pump 4 and the like according to the control signal transmitted from the CPU box 93. In this embodiment, the same number of pump management panels 94 as the number of squeeze pumps 4 are provided.

The pump management panel 94 controls the flow rate of the mixture supplied to the foaming cylinder 5 by controlling the rotational speed of the rotor in the squeeze pump 4.
The pump management panel 94 also controls the amount of foaming material supplied to the compressed air supplied by the compressor 3 by controlling the flow rate of the foaming material by the foaming material supply pump 2.

The liquid production management board 94 manages the mixing of the A liquid and the B liquid and the like according to the signal transmitted from the CPU box 93. The liquid production management board 94 controls the A liquid addition pump 62, the B liquid addition pump 72, the B liquid mixer 73, the submersible pump 74a, the pump 75a, and the like, and manages the blending of the mixture.
In addition, since the compressor 3 is a constant pressure supply, direct quantity control is not performed.

The injection flow rate of the foam is set by the ratio of the excavated soil amount to the excavated soil amount.
The amount of excavated soil per minute is calculated based on the outer diameter of the excavator and the excavation speed, and the amount of foam injected per minute is calculated by multiplying the amount by the injection rate.

A calculation example is shown below. The conditions in the calculation example are shown below. In addition, although 0.1 MPa is added in the calculation example, this means 0.1 MPa of atmospheric pressure. Since the atmospheric pressure is 0.1 MPa on the ground surface, even if 0 is displayed on the pressure gauge, 0.1 MPa is acting.
Excavation outer diameter: 12.53m
Injection rate for excavated soil volume: 40%
Chamber earth pressure: 0.4 MPa
Drilling speed: 50 mm / min = 0.050 m / min
Foaming ratio: 8 times Bubble dilution ratio: 100 times Injection system: 8

Calculation of foam injection amount Q: Q = 12.53 × 12.53 × π / 4 × 0.05 × 0.4 × 1000
= 2464.9L / min
・ Injection quantity Qa per injection system
Qa = 2464.9 ÷ 8 = 308.1 L / min

・ Flow rate Q _Liq of foaming material supply pump 2
Q _Liq = 308.1 ÷ 8 = 38.5 L / min
_-Flow rate Q _{LiqA of the} liquid A addition pump 62
Q _LiqA = 38.5 ÷ 100 = 0.385L / min

・ Injection amount of air per direction Q _air
Q _air = (308.1-38.5) × (0.4 + 0.1) × 10 = 1348 L / min

・ Air flow rate Q _airs borne by the squeeze pump when the air injection amount is supplied to the pump suction at 0.6 MPa.
Q _airs = 1348 ÷ [(0.6 + 0.1) × 10] = 192.6 L / min

・ Discharge amount Qs of squeeze pump
Qs = Q _Liq + Q _airs = 38.5 + 192.6 = 231.1 L / min

If the pressure of the foamed cylinder 5 (indication of the pressure sensor 54) is 0.7 MPa, the air amount display changes, so the flow rate of the foam (indication of the flow meter 53) is as follows.
1348 ÷ [(0.7 + 0.1) × 10] + 38.5 = 207 L / min

  The air flow rate and pressure of the compressor 3 are constantly supplied at 1348 × 8 = 10784 L / min, 0.6 MPa.

  By measuring the earth pressure in the chamber and calculating the flow rate of the foam corresponding to this pressure, the squeeze pump corresponding to the earth pressure is taken into account in consideration of the speed control of the foaming material supply pump 2 and the expansion ratio. The flow rate of 4 can be controlled.

  According to the bubble system 1 of the present embodiment, since the foam is injected through the squeeze pump 4, an injection pressure of about 2 MPa can be ensured regardless of the ability of the compressor 3. Therefore, it is possible to inject the foam even for excavation of natural ground under high water pressure conditions.

  By the injection by the squeeze pump 4, the injection speed can be kept constant. Therefore, it can inject | pour by fixed quantity and can inject | pour stably also in construction with a low earth covering.

  Since the piping from the pump (squeeze pump 4) to the foam cylinder 5 can be provided by a single system, the injection volume and injection pressure can be easily managed.

  Since the bubble injection system 1 is automatically controlled according to the earth pressure to control the injection flow rate and the injection pressure of the foam, the workability is excellent.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and the above-described constituent elements can be appropriately changed without departing from the spirit of the present invention.

For example, the number of squeeze pumps used in the foam injection system is not limited, and may be set as appropriate according to the excavation cross-sectional shape.
The relationship between the number of squeeze pumps and the number of injection ports may be set as appropriate. For example, the injection may be performed from two injection ports using one squeeze pump.

  Moreover, the transportation method of A liquid and B type material is not limited to the method shown by the said embodiment, What is necessary is just to perform suitably, for example, pumping with a transport pipe.

  Moreover, in the said embodiment, although B liquid was produced | generated by mixing B type material and fresh water on-site, you may carry in B liquid mixed beforehand.

The discharge capacity of the compressor and each pump is not limited.
Although the foam was produced | generated via the foam cylinder, the production | generation method of a foam is not limited.

DESCRIPTION OF SYMBOLS 1 Bubble injection system 2 Foaming material supply pump 3 Compressor 4 Squeeze pump 5 Foam cylinder 54 Pressure sensor

Claims (2)

A bubble injection system for injecting foam into a face or chamber,
A foaming material supply pump, a compressor, a squeeze pump, and a foam cylinder,
The squeeze pump pressurizes a mixture obtained by mixing the foaming material pumped through the foaming material supply pump and the compressed air pumped through the compressor, and pressurizes the pressurized mixture. A bubble injection system characterized by being delivered to a foam cylinder. A pressure sensor is provided near the discharge port of the foam cylinder,
The bubble injection system according to claim 1, wherein the squeeze pump is controlled in accordance with an earth pressure in the chamber and a pressure value measured by the pressure sensor.

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