JPH0757870B2 - Method and apparatus for manufacturing ground injection chemicals - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing a pollution-free ground injection chemical liquid for consolidating soft or leaking ground containing water glass and carbon dioxide gas as active ingredients, and more particularly to a method for producing pressurized carbon dioxide gas. A method of manufacturing a ground injection chemical solution that simplifies the control of the absolute amount, mixes and absorbs the amount of carbon dioxide gas relative to the water glass aqueous solution in a closed mixing tank at a fixed ratio, and can produce a uniform injection chemical solution without vaporization of carbon dioxide gas. And equipment.

[0002]

2. Description of the Related Art In recent years, a chemical solution injection technique using harmless carbon dioxide gas as a reaction agent of a water glass injection method has been proposed, but it is difficult to put it into practical use, and a gelling method having a long gelation time has been actually implemented. Absent.

When carbon dioxide gas is used as a reaction agent in water glass grout, the method of blowing carbon dioxide gas into a water glass aqueous solution and then injecting it causes a slow dissolution of carbon dioxide gas, and most of carbon dioxide gas deviates into the air. It is impossible to grasp how much carbon dioxide gas should be blown into water glass of what concentration and how much gelling time of gelation should be obtained. It hasn't arrived.

That is, conventionally, there has been no technique for setting a gelation time by absorbing a predetermined carbon dioxide gas in a water glass aqueous solution without waste.

Therefore, in order to dissolve the carbon dioxide gas in the water glass solution without being dissipated, the water glass and the carbon dioxide gas are supplied into the closed pressure-resistant container to cause the reaction while maintaining the carbon dioxide gas at a high pressure, and this pressure is utilized. There is proposed a method of injecting a liquid that has reacted in a spray tower having a closed pressure-resistant structure, or a method of using a mist-blown fluid nozzle to collect the reacted liquid in a receiving tank.

However, even though it is possible to sufficiently carry out the reaction in any of these, the injectate thus obtained is immediately gelated, or a gel is liable to be partially formed, and therefore, a predetermined gelation is caused. It is difficult to obtain a homogeneous injection liquid that gels with time, and therefore it is difficult to infiltrate the same into the ground with a pump, and it is not practical.

Further, the carbon dioxide gas of the increased pressure is ejected from the carbon dioxide gas storage tank at a high speed by means of a spray nozzle, and at the same time water glass is supplied to the nozzle, whereby the water glass is atomized and the carbon dioxide gas is rapidly converted into water glass. A method is proposed in which droplets obtained by being absorbed into the ground are collected in a receiving tank and then injected into the ground, or they are not collected in the receiving tank and are diffused into the ground by using the jet pressure from a nozzle. Has been done.
(See JP-A-53-69409).

However, in this method, the reaction is carried out rapidly because the water glass is atomized in carbon dioxide gas, but the gelling time is shortened and gelation occurs in the receiving tank. It is not possible to inject a grout that is thick and has a short gelation time and high strength.

Further, even if the method of diffusing the liquid droplets into the ground by utilizing the jet pressure of carbon dioxide gas from the mist blowing nozzle without collecting them in the receiving tank, as a practical problem, the liquid droplets having a short gelation time reach the purpose of ground injection. It is impossible to diffuse to the extent that it can be obtained, and a small amount of water glass droplets in a large amount of carbon dioxide gas makes the ground porous and only locally consolidates, and it is homogeneous. Hardening is difficult.

In order to solve the above problems, a pressure chamber is provided at the tip of the double injection pipe, and a method is developed in which water glass and carbon dioxide gas or water glass and carbonated water are joined and injected at the same time in this pressure chamber. Has been done. However, this method is suitable for injection with a short gelling time of a few seconds, but with injection with a long gelation time, carbon dioxide gas evaporates from the injection liquid while the injection liquid permeates into the ground, It is not possible to obtain a solidifying effect.

In the method of gradually blowing carbon dioxide into the sealed high-pressure container, the mixing ratio of water glass and carbon dioxide changes with the passage of time, and the reaction of water glass in contact with carbon dioxide is suddenly carried out. Therefore, it is difficult to mix them uniformly. Further, when the water glass and carbon dioxide gas which have been press-fitted into the high-pressure container are discharged, the carbon dioxide gas is vaporized, and a predetermined gelling time cannot be secured.

[0012]

The object of the present invention is not only to simplify the control of the absolute flow rate of the pressurized carbon dioxide gas and to mix the carbon dioxide gas amount with respect to the aqueous solution of water glass at a constant ratio in the closed mixing tank. Carbon dioxide gas is almost completely dissolved and absorbed in a water glass aqueous solution to obtain an injectate having a long gelation time, and after injection, carbon dioxide gas in the injectate is gelated in a predetermined gelation time without vaporization, which is a conventional technique. It is an object of the present invention to provide a method and an apparatus for manufacturing a ground injection chemical solution with improved drawbacks.

[0013]

In order to achieve the above object, according to the method of the present invention, a water glass aqueous solution and carbon dioxide gas are mixed in a fixed ratio in a closed mixing tank having an agitator and a discharge port inside. While supplying pressure, while operating the stirrer, the carbon dioxide gas is absorbed in the water glass aqueous solution in the closed mixing tank, and then the absorption causes the pressure in the closed mixing tank to decrease to a desired value. In order to achieve the above-mentioned object, in order to achieve the above-mentioned object, according to the device of the present invention, a closed seal equipped with a stirrer and a discharge port is provided. A water tank supply line connected to the mixing tank and the closed mixing tank to supply a water glass aqueous solution into the mixing tank, and a carbon dioxide gas supply connected to the closed mixing tank to supply carbon dioxide gas into the mixing tank. La And down, characterized in that comprising a carbon dioxide blowing nozzles provided in the carbon dioxide supply line.

The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is an explanatory view of a specific example of an apparatus for carrying out the method of the present invention, which comprises a closed mixing tank 1, a water glass supply line 2, a carbon dioxide gas supply line 3, and a carbon dioxide gas blowing nozzle 4.

The closed mixing tank 1 has a stirrer 5 and a discharge port 6 inside. Further, the water glass supply line 2 is connected to the closed mixing tank 1 through a pipe 7a, and the water glass aqueous solution storage tank 8, the pump 9, and the
A flow meter 10 is arranged, and the water glass aqueous solution is sent from a storage tank 8 at a flow rate determined by a pump 9 and is pressurized and supplied to the closed mixing tank 1 through a flow meter 10 and a pipe 7a. At this time, the water glass aqueous solution may be supplied through the pipe 7b or 7c. 11, 12 and 13 are check valves and 14 is a pressure gauge.

On the other hand, the carbon dioxide gas supply line 3 is connected to the closed mixing tank 1 through a pipe 15, and a high pressure carbon dioxide container 16, a pressure reducing valve 17 and a carbon dioxide blowing nozzle 4 are sequentially arranged in the pipe 15. This carbon dioxide gas blowing nozzle 4 is constructed by forming a nozzle hole 4b in the center of a disc 4a, and carbon dioxide gas is hermetically mixed by a pipe 15 from a carbon dioxide gas high pressure container 16 through a pressure reducing valve 17, a carbon dioxide gas blowing nozzle 4. It is supplied under pressure to the tank 1.

That is, the water glass aqueous solution is pressurized and supplied to the closed mixing tank 1 through the water glass supply line 2, and the carbon dioxide gas is also pressurized and supplied to the closed mixing tank 1 through the carbon dioxide gas blowing nozzle 4 through the carbon dioxide gas supply line 3. To be done. 18 is a check valve.

The aqueous solution of water glass and carbon dioxide gas supplied under pressure to the closed mixing tank 1 react rapidly by the stirring operation by the stirrer 5 to lower the pressure in the closed mixing tank 1 to a desired pressure, for example, 1 Kg / fcm. Easily reach pressures within ² . The obtained mixed liquid 19 is discharged to the injection mechanism as the ground injection chemical liquid 21 from the discharge port 6 equipped with the squeezing valve 20. Therefore, the ground injection chemical solution 19 can be easily held at a desired gelation time.

In the present invention, during the mixing, the carbon dioxide gas pressure and the hole diameter of the carbon dioxide gas blowing nozzle 4 are arbitrarily changed and combined to determine the carbon dioxide gas blowing amount corresponding to the pressure in the closed mixing tank 1. Thus, the aqueous solution of water glass and carbon dioxide can be mixed at a constant ratio. The gas pressure of the carbon dioxide gas is arbitrarily changed by operating the pressure reducing valve 17, and the hole diameter is arbitrarily changed by replacing the carbon dioxide gas blowing nozzle 4 with one having a different nozzle hole diameter.

[0020]

Next, the operation will be described with reference to the diagrams in which the experimental results shown in FIGS. Figure 2 shows a 0.8 mm nozzle hole in the center of a disk (thickness: 3 mm), and carbon dioxide pressure (35,
30, 25 Kgf / cm ² ) and the amount of carbon dioxide gas blown out, the amount of carbon dioxide gas blown out (g / min) at a set carbon dioxide pressure is a constant flow rate within a certain range, and It can be seen that the amount of gas blowout gradually decreases. Therefore, the amount of carbon dioxide gas blown out corresponding to the pressure in the closed mixing tank can be controlled by changing the carbon dioxide gas pressure. The carbon dioxide gas pressure can be arbitrarily changed by the pressure reducing valve.

FIG. 3 is a diagram showing the relationship with the amount of carbon dioxide gas blown out when the nozzle hole diameter is changed while keeping the carbon dioxide gas pressure constant (35 Kgf / cm ² ). By combining several nozzles, it becomes possible to arbitrarily control the blowing amount of carbon dioxide gas corresponding to the pressure in the closed mixing tank.

The line I in FIG. 3 is the nozzle 2 having a nozzle hole diameter of 1 mm.
The figure below shows the carbon dioxide blowing rate when using one nozzle (a carbon dioxide blowing rate of 450 g / min per nozzle) and one nozzle with a nozzle hole diameter of 0.4 mm (blowing rate of 100 g / min) at the same time. Further, when the carbon dioxide gas pressure is made constant from the figure, the carbon dioxide gas blowing nozzles having different nozzle hole diameters can be replaced and used corresponding to the pressure in the closed mixing tank.

FIG. 4 shows the relationship between the pressure in the closed mixing tank and the reaction rate. From this graph, carbon dioxide gas was absorbed into the aqueous solution of water glass by stirring, and the pressure was decreased until the pressure in the tank reached 0.1 kgf / cm ^2. It is clear that carbon dioxide is absorbed by more than 98%. That is, from FIG. 4, the carbon dioxide gas is almost absorbed by reducing the pressure in the closed mixing tank to 1 kgf / cm ² or less. The relationship between the amount of carbon dioxide gas absorbed in the aqueous solution of water glass and the gelation time can be set in advance depending on the type, concentration and temperature of the water glass.

As an example, when carbon dioxide gas is absorbed from the above 98% or more and then discharged from the closed mixing tank, 25% by volume of 3%
Fig. 5 shows the relationship between the amount of carbon dioxide gas absorbed per 1 m ^{3 of the} No. water glass aqueous solution and the gelation time.

[0025]

FIG. 6 is a diagram showing a specific embodiment of the present invention, in which a fixed amount of the water glass aqueous solution stored in the water glass aqueous solution storage tank 8 is sent by a pump 9 and a flow meter 10 is provided. After confirming the flow rate, the pressure is supplied into the closed mixing tank 1 through the pipe 7a or 7b. A main valve SV is provided on the suction side pipe 7 a of the pump 9.

Further, liquefied carbon dioxide gas high pressure vessels 16, 16a, 16b
A carbon dioxide gas pressure-feeding pipe 15 is connected to the base of the above, and a main valve SV, a heater 22, a pressure reducing valve 17, and a carbon dioxide gas distiller 23 are provided on this pipe, and the liquefied carbon dioxide gas is vaporized by the heater 22. The pressure reducing valve 17 reduces the pressure to a specified level,
Stored in 23 at a certain pressure. Branch pipes 15a, 15b, 15c, 15d are provided in parallel in a pipe 15 after the carbon dioxide gas distiller 23, and main valves V, V1, V2, V3 are provided in the respective branch pipes and carbon dioxide blowing nozzles 4, 4a. 4b and 4c are provided, each branch pipe is connected to a pipe 15e, and this pipe is connected to a carbon dioxide gas pressure feeding pipe 15. The end of the pipe 15 is connected to the closed mixing tank 1. The carbon dioxide pressure to be sent is piped.
It is confirmed by pressure gauges P1 and P2 provided at 15. Further, in the above device, the check valves 11, 12, and 18 are provided to prevent the reverse flow of the water glass aqueous solution and the carbon dioxide gas.

The carbon dioxide gas blowing nozzles 4, 4a, 4b,
No. 4c has different nozzle hole diameters, and the carbon dioxide blowing amount corresponding to the pressure in the mixing chamber is controlled by a single carbon dioxide gas blowing nozzle or a combination of two or more nozzles to control the flow rates of the water glass aqueous solution and the carbon dioxide gas. 5, the pressure stirring and mixing pressure was reduced at a constant ratio in the closed mixing tank 1 having the pressure gauge 14, the squeezing valve 20 and the discharge port 6. The resulting mixture
19 is introduced into the injection mechanism as the ground injection liquid 21 discharged from the discharge port 6.

Specifically, 25 volume% of a No. 3 water glass aqueous solution and carbon dioxide gas are pressure-filled in a closed mixing tank, and then mixed and stirred to reduce the pressure in the tank to 0.02 kgf / cm ² or less. A homogeneous injection liquid with a long gelation time was obtained and discharged from the discharge port 6 and led to the injection mechanism.

In the present invention, in addition to water glass and carbon dioxide gas, any water glass reaction agent such as an inorganic reaction agent such as carbonate or chloride, an organic reaction agent or the like may be used in combination.

[0030]

As described above, according to the present invention, the hole diameter and the carbon dioxide gas pressure of the carbon dioxide gas blowing nozzle are arbitrarily changed, and the water glass aqueous solution and the carbon dioxide gas are mixed at a constant ratio with a stirrer and a discharge port. The mixture is supplied by pressurizing it into the mixing tank, and the carbon dioxide gas is absorbed by the stirring action to quickly reduce it to the desired pressure. Even if it is discharged into the air, the carbon dioxide gas hardly vaporizes, and the gelation time is accurate. It is possible to obtain an injectable solution adjusted to, particularly an injectable solution having a long gelation time.

Further, even if it is injected into the ground, carbon dioxide gas is hardly vaporized regardless of the injection pressure, and a homogeneous injection chemical can be injected, so that a homogeneous and sufficient consolidation function is exhibited. A solid body is obtained.

Since the flow rate of carbon dioxide gas is controlled by the carbon dioxide gas blowing nozzle, the operation is simplified and the chemical solution can be injected easily and the cost can be greatly improved.

[Brief description of drawings]

FIG. 1 is an explanatory view of an apparatus for carrying out the method of the present invention.

FIG. 2 is a diagram showing a relationship between carbon dioxide pressure (35, 30, 25 Kgf / cm ² ) and carbon dioxide blowing amount.

FIG. 3 is a diagram showing a relationship with the amount of carbon dioxide gas blown out when the nozzle hole diameter is changed while keeping the carbon dioxide gas pressure constant (35 Kgf / cm ² ).

FIG. 4 is a diagram showing a relationship between a pressure in a closed mixing tank and a reaction rate.

FIG. 5 is a graph showing the relationship between the amount of carbon dioxide gas absorbed per 1 m ^{3 of a} 25% by volume aqueous solution of No. 3 water glass and the gelation time.

FIG. 6 is a diagram showing a specific embodiment of the present invention.

[Explanation of symbols]

 1 Closed Mixing Tank 2 Water Glass Supply Line 3 Carbon Dioxide Supply Line 4 Carbon Dioxide Blow Out Nozzle 5 Stirrer 6 Discharge Port 19 Mixed Liquid 21 Ground Injection Chemical Liquid

Claims (6)

[Claims] 1. A water glass aqueous solution and carbon dioxide gas are pressurized and supplied at a fixed ratio into a closed mixing tank having an agitator and a discharge port inside, and the water glass aqueous solution is added in the closed mixing tank while operating the agitator. Carbon dioxide gas is absorbed into the water, and then the water glass aqueous solution in which the carbon dioxide gas is absorbed is discharged from the discharge port after the pressure in the closed mixing tank is lowered to the desired value by the absorption to obtain a ground injection chemical solution. And a method for producing a ground injection chemical solution. 2. A process according to claim 1, the supply of the carbon dioxide and carrying out the carbon dioxide blowing nozzle. 3. The manufacturing method according to claim 2, wherein the hole diameter of the carbon dioxide gas blowing nozzle is switchable. 4. The pressure in the closed mixing tank is approximately 1 kgf / c.
A method for producing a ground injection chemical liquid, characterized in that the pressure is reduced to within m ² . 5. A closed mixing tank having a stirrer and a discharge port inside, a water glass supply line connected to the closed mixing tank and supplying a water glass aqueous solution into the mixing tank, and connected to the closed mixing tank. And a carbon dioxide gas supply line for supplying carbon dioxide gas into the mixing tank, and a carbon dioxide gas blowing nozzle provided in the carbon dioxide gas supply line. 6. The apparatus according to claim 5, wherein the carbon dioxide blowing nozzle has a switchable hole diameter.