JPS61261514A - Chemical grout injector - Google Patents

Abstract

PURPOSE:To inject a chemical grout into the ground by joinint it with CO2 gas at a fixed ratio by a method in which a grout-feeding pipe through which a grout is injected into the ground and a CO2 high-pressure container are provided, and a CO2 blow-out nozzle is provided to a CO2 pressure-feeding pipe. CONSTITUTION:A storage tank 1 for aqueous water glass solution as a grout, an injection pump 2, and a flow meter 3 are provided for a chemical grout injector. A water glass aqueous solution is sent under pressures through the flow meter 3 from a pipe 4 into the injection pipe 6. A pipe 8 is connected to the mouth piece of a high-pressure CO2 gas container 7, and the end of the pipe 8 is connected to the pipe 6. A reducing valve 9 is provided in the pipe 8, and a CO2 gas-blow-out nozzle 10 with a nozzle port 10b at the central part of a disc 10a is provided amount of CO2 gas to be blown out corresponding to the ground pressure can thus be obtained simply, and chemical grout can also be easily injected at low cost.

Description

[Detailed Description of the Invention] Industrial Application Field This invention mainly relates to a chemical solution for consolidating the ground or water supply by jointly injecting a water glass-based solidification chemical solution and carbon dioxide gas into the ground such as soft ground or leaky ground. Relating to an injection device.

Conventional technology Conventionally, a chemical injection consolidation method has been adopted in which a chemical solution containing a water glass (sodium silicate) solution and carbon dioxide gas as hardening agents is injected into soft or leaking ground to solidify the ground or stop water. There is.

When combining the water glass aqueous solution and carbon dioxide gas and injecting the mixture into the ground, the absolute amount of carbon dioxide gas to be mixed with the water glass aqueous solution must be injected at a nearly constant ratio to solidify the water glass uniformly. No body is formed. The reason for this is that when the pressure in the ground changes, the amount of carbon dioxide gas injected changes significantly, the ratio with water glass becomes inconsistent, and the colloid-like material produced by the reaction between water glass and carbon dioxide becomes uneven. It has been pointed out that this occurs and a uniform solidified body cannot be obtained.

As part of the solution to the above problems,
A chemical liquid injection device as seen in Japanese Patent No. 42769 has been proposed. This proposed device is a chemical liquid injection device comprising an injection pipe inserted into the ground, a water glass storage tank connected to the injection pipe, and a carbon dioxide gas storage tank connected to the injection pipe. A pressure fluctuation sensing device is provided between the carbon dioxide gas storage tank and the injection pipe, and the pressure fluctuation sensing device includes an automatic flow rate control valve and an automatic flow rate control valve in order downstream between the injection pipe and the carbon dioxide storage tank. , a flow meter connected to the flow rate indicating regulator via a differential pressure transmitter and a switching calculator, and a pressure transmitter also connected to the flow rate indicating regulator via a graphic computing unit,
Based on the calculation results of both wave counters, the flow rate indicator controller operates the automatic flow rate control valve to control the absolute flow rate of carbon dioxide gas, and the absolute flow rates of the water glass aqueous solution and carbon dioxide gas are combined at a constant ratio. The method is to inject.

Problems to be Solved by the Invention By the way, in such a conventional chemical injection device,
By installing a pressure fluctuation sensing device between the carbon dioxide gas storage tank and the injection pipe, the absolute flow rate of water glass solution and carbon dioxide gas are combined at a constant ratio regardless of fluctuations in ground pressure (kg/ryal), and the water glass solution and carbon dioxide gas are combined into the ground. It can bring benefits that allow injection. However, in practice, the control system that senses changes in ground pressure and pumps the amount of pressurized carbon dioxide in response to the ground pressure is complicated, resulting in increased equipment costs for the control system. , and there is a practical problem that requires careful operation management to check, manage, and maintain the performance of each control element.

Therefore, it is necessary to simplify the control of the absolute flow rate of the pressurized carbon dioxide gas and inject the mixture into the ground by combining the amount of carbon dioxide gas with respect to the water glass aqueous solution at a constant ratio within the permissible range of the ground pressure.

Means for Solving the Problems This invention solves the above problems, and the details thereof will be explained below using FIG. 1 corresponding to an embodiment.

FIG. 1 is a diagram showing the basic concept of this invention.

In the figure, 1 is a water glass aqueous solution storage tank as an injection material;
2 is an injection pump, 3 is a flow meter, and the water glass solution is discharged at a predetermined flow rate by the injection pump, and is forced through the flow meter into an injection pipe 6 inserted into the ground 5 through a pipe 4. . The above is the same as the water glass injection system of the conventional chemical liquid injection device. Here, the pipe line including the injection pipe 6 from the water glass aqueous solution storage tank 1 is referred to as the injection material feeding pipe line.

In this invention, a pipe 8 is connected to the carbon dioxide gas high-pressure container 70, and the end of this pipe is connected to the injection pipe 6. A pressure reducing valve 9 and a disc 10a are provided on the pipe 8.
A chemical liquid injection device is constructed by providing a carbon dioxide gas blowing nozzle 10 with a nozzle hole 10b in the center thereof.

The piping 8 has nozzles 10 with different nozzle hole diameters.
be installed so that they can be replaced. In addition, several carbon dioxide gas blowing nozzles 10 with different nozzle hole diameters are arranged in parallel in the carbon dioxide gas pressure feeding pipe 8, and each nozzle 1
0 may be provided so as to be switchable.

Effect Next, the effect will be explained based on the diagrams of FIGS. 2 and 3, which are graphs of experimental results.

Figure 2 shows a nozzle hole with a diameter of 0.8 mm drilled in the center of a disk (plate thickness 3 mm), and carbon dioxide gas pressure (35,30°25 kg/c).
This is a diagram showing the relationship between carbon dioxide gas blowout amount (g/min) and carbon dioxide gas blowout amount at a set carbon dioxide gas pressure, and the carbon dioxide gas blowout amount (g/min) becomes a constant flow rate within a certain range, and at a certain limit point, the carbon dioxide gas blowout amount decreases. It can be seen that it gradually decreases. therefore,
The amount of carbon dioxide gas blown out corresponding to the ground pressure can be controlled by changing the carbon dioxide pressure.

Carbon dioxide pressure can be changed arbitrarily using a pressure reducing valve.

Figure 3 shows a constant carbon dioxide pressure (35k, e/c7/l)
This is a diagram showing the relationship between carbon dioxide gas blowout amount when the nozzle hole diameter is different, and by combining several carbon dioxide gas blowout nozzles with different nozzle hole diameters, the amount of carbon dioxide gas corresponding to the ground pressure can be increased. The line 1 in the figure shows two nozzles with nozzle hole diameter l Im (carbon dioxide gas blowout amount of one nozzle 450 g/m1n) and a nozzle with nozzle hole diameter 0.4 mm. (Blowout amount: 100 g/m1n) The amount of carbon dioxide gas blown out is shown when one piece is used at the same time.

Further, as shown in the figure, when the carbon dioxide gas pressure is kept constant, carbon dioxide gas blowing nozzles with different nozzle hole diameters can be replaced and used in accordance with the ground pressure.

Embodiment FIG. 4 is a diagram showing an embodiment of the present invention, in which a fixed amount of water glass solution stored in a water glass solution storage tank 1 is discharged by an injection pump 2, and the flow rate is measured by a flow meter 3. Injection pipe 6 is confirmed and inserted into the ground 5 through pipe 4
injected into the body. A main valve Sv is provided in the piping 4 on the suction side of the injection pump 2.

A carbon dioxide gas pressure feeding piping 8 is connected to the caps of the liquefied carbon dioxide high pressure containers 7.7', 7'', and on this piping, a main valve Sv, a heater 11, a pressure reducing valve 9, a carbon dioxide gas unit 12 are provided, The liquefied carbon dioxide is turned into vaporized carbon dioxide by the heater 11, reduced to a predetermined pressure by the pressure reducing valve 9, and stored at a predetermined pressure in the carbon dioxide hermetic container 12.A branch pipe is connected to the piping after the gas reservoir. 8a - 8b - 8c s 8d are provided in parallel, and each branch pipe is provided with main valves V, V1, V2, and ■3, and carbon dioxide gas blowing nozzles 10, 10', 10", 10
/N is provided, each branch pipe is connected to a pipe 8', and this pipe is connected to a carbon dioxide gas pressure feeding pipe 8. Said piping 8
The distal end of is connected to the injection tube 6. The pressure of the carbon dioxide gas to be pumped is confirmed by pressure gauges P1 and P2 provided in the piping 8.

The above carbon dioxide gas blowing nozzle 10.10', 10", 10"
The nozzle hole diameters are different, and the amount of carbon dioxide blowing out corresponding to the ground pressure is controlled by a single carbon dioxide gas blowing nozzle or a combination of two or more nozzles, and the flow rates of the water glass aqueous solution and carbon dioxide gas are combined at a constant ratio. It is injected into the ground via the injection pipe 6.

In the present invention, the injection material for ground injection is an aqueous solution of water glass or a mixed solution of water glass and a reaction side, including an injection solution containing cement, etc., which contains an alkali and the alkali causes a neutralization reaction with carbon dioxide gas. material can be used.

As described in detail, this invention allows the amount of carbon dioxide gas to be blown out corresponding to the ground pressure to be easily obtained by simply changing the hole diameter of the carbon dioxide gas blowing nozzle and the carbon dioxide gas pressure. Since it can be combined with gas at a fixed ratio and injected into the ground, it has the effect of obtaining a uniform solidified body.

In addition, since the carbon dioxide gas flow rate is controlled by the carbon dioxide gas blowing nozzle, the chemical liquid injection operation is also simplified, and a significant improvement can be expected in terms of ease of chemical liquid injection and cost.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the basic concept of this invention, Fig. 2 is a diagram showing the relationship between carbon dioxide gas pressure and carbon dioxide gas blowing amount for carbon dioxide gas blowing nozzle hole diameters of 0 and 8, and Fig. 3 is a diagram showing the carbon dioxide gas pressure. 35
FIG. 4 is a diagram showing the relationship between the nozzle hole diameter and the amount of carbon dioxide gas blown out in kg/a/l, and is a diagram showing an embodiment of the present invention. In the figure, 1 is a water glass aqueous solution storage tank, 2 is an injection pump, 3 is a flow meter, 6 is an injection pipe, 7 is a carbon dioxide gas high pressure container, 9 is a pressure reducing valve, 10 is a carbon dioxide gas blowing nozzle, 11 is a heater, 12 is a carbon dioxide gas unit. Figure / Figure CO, Blowout amount B/m+n @ η diagram

Claims (3)

[Claims] (1) Consists of a liquid supply pipeline for injection material for ground injection, and a high-pressure carbon dioxide gas container connected to the liquid supply pipeline via a carbon dioxide gas pressure supply pipeline, and a carbon dioxide gas blowing nozzle is connected to the carbon dioxide gas pressure supply pipeline. A chemical liquid injection device characterized in that: (2) The chemical liquid injection device according to claim 1, which uses a nozzle having a nozzle hole in the center of a disk as the carbon dioxide gas blowing nozzle. (3) The chemical liquid injection device according to claim 1, wherein several carbon dioxide gas blowing nozzles with different nozzle hole diameters are arranged in parallel and switchable to the carbon dioxide gas pressure feeding pipeline.