JP4334755B2 - Gas-liquid mixing method using dissolution diffusion method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas-liquid mixing method using a solution diffusion method for mixing a gas and a liquid.
[0002]
[Prior art]
Conventionally, for example, there has been a demand to use functional water obtained by adding a small amount of carbonic acid or ammonia to pure water or the like as a cleaning liquid used in a manufacturing process of semiconductors, liquid crystals and the like. As a method for producing a mixed liquid containing a small amount of carbonic acid, ammonia or the like, that is, functional water, it is usually considered to obtain a functional water by dissolving a small amount of a soluble gas such as carbon dioxide gas or ammonia gas in pure water or the like.
[0003]
[Problems to be solved by the invention]
Even in the above-described method of mixing gas and liquid, desired functional water can be usually obtained. However, when trying to obtain a mixed liquid in which a very small amount of ammonia or carbonic acid is injected by this gas-liquid mixing method, especially when the total liquid volume is small, a continuous small amount of carbon dioxide gas or ammonia gas, etc. There is a problem that it is difficult to obtain a gas-liquid mixed solution by mixing the soluble gas and a large amount of pure water.
[0004]
In addition, when trying to obtain a gas-liquid mixture by mixing gas-dissolved water in which a soluble gas is dissolved and water, a control valve and a metering injection pump will be used. When the flow rate is small, a pipe having a small diameter must be used as the apparatus, and a control valve, a metering injection pump or the like cannot be used for such a pipe, and there is a problem that mixing control becomes difficult.
[0005]
An object of the present invention is to solve the above-mentioned problems and to provide a gas-liquid mixing method using a dissolution diffusion method effective when mixing a gas and a liquid, particularly when mixing a small amount of gas with a liquid. It is.
[0006]
[Means for Solving the Problems]
In the gas-liquid mixing method using the dissolution diffusion method of the present invention, the soluble gas of the target component is dissolved in the first solution, and the concentration of the obtained gas dissolved water and the target component is lower than that of the gas dissolved water. When the gas solution is brought into contact with the second solution via the porous medium and the gas-dissolved water is injected into the second solution by diffusion, a first chamber for storing the first solution is formed in one of the porous media, A second chamber for storing the second solution is formed on the other side of the porous medium, and a soluble gas is injected into the first solution by applying pressure to the first solution in the first chamber. In injecting the gas-dissolved water obtained by dissolution into the second solution in the second chamber via the porous medium, the pressure injection amount of the gas-dissolved water into the second solution, and the gas-dissolved water The ratio of the diffusion injection amount that is diffused and injected into the second solution is 1: 9 or more .
[0007]
In the present invention, the soluble gas containing the component of interest is once dissolved in the first solution, and injection control from the obtained gas-dissolved water to the second solution is performed by diffusion through the porous medium, A liquid mixture containing a trace amount of the component of interest can be obtained.
[0008]
In the present invention, when the soluble gas is supplied to the first solution in the first chamber under pressure, the pressure injection amount of the gas dissolved water into the second solution and the gas dissolved water are diffused. The ratio of the diffusion injection amount injected into the second solution is set to 1: 9 or more. If the ratio between the pressure injection amount and the diffusion injection amount is less than 1: 9, the controllability by pressure injection determines the overall controllability rather than the controllability by diffusion injection, meaning the diffusion injection method using a porous medium. This is because there is a case where there is no case.
[0009]
At that time, the porous medium has a bottomed cylindrical shape with one end closed, the first chamber is formed inside the bottomed cylindrical porous medium, and the first chamber is formed outside the bottomed cylindrical porous medium. Two chambers are formed. Alternatively, the porous medium has a cylindrical shape, the first chamber is formed inside the cylindrical porous medium, the second chamber is formed outside the cylindrical porous medium, and the cylindrical shape The porous medium is closed at one end. Alternatively, the porous medium has a flat sheet shape, the first chamber is formed on one side of the flat sheet-shaped porous medium, and the second chamber is formed on the other side of the flat sheet-shaped porous medium. Form. In either case, the present invention can be more suitably implemented.
[0010]
In addition, the gas-liquid mixing method using the dissolution diffusion method of the present invention dissolves the soluble gas of the target component in the first solution, and the concentration of the obtained gas-dissolved water and the target component is higher than that of the gas-dissolved water. When the low second solution is brought into contact with the second medium through the porous medium and the gas-dissolved water is injected into the second solution by diffusion, a first chamber for storing the first solution is formed in one of the porous media. Then, a second chamber for storing the second solution is formed on the other side of the porous medium, and the first solution is injected in the first chamber by applying a soluble gas under pressure to the first solution. In the injection of the obtained gas-dissolved water into the second solution in the second chamber through the porous medium , the pressure injection amount of the gas-dissolved water into the second solution, the gas dissolved water the ratio of the diffusion injection amount to be injected into the second solution by diffusing 1: 9 or more and thereby, the porous medium Has a bottomed cylindrical shape with one end closed, the first chamber is formed inside the bottomed cylindrical porous medium, and the second chamber is formed outside the bottomed cylindrical porous medium. It is characterized by this.
[0011]
Furthermore, the gas-liquid mixing method using the dissolution diffusion method of the present invention dissolves the soluble gas of the component of interest in the first solution, and the concentration of the obtained gas-dissolved water and the component of interest is higher than that of the gas-dissolved water. When the low second solution is brought into contact with the second medium through the porous medium and the gas-dissolved water is injected into the second solution by diffusion, a first chamber for storing the first solution is formed in one of the porous media. Then, a second chamber for storing the second solution is formed on the other side of the porous medium, and the first solution is injected in the first chamber by applying a soluble gas under pressure to the first solution. In the injection of the obtained gas-dissolved water into the second solution in the second chamber through the porous medium , the pressure injection amount of the gas-dissolved water into the second solution, the gas dissolving the ratio of the diffusion injection volume water is diffused is injected into the second solution 1: 9 or more and then, the porous medium is cylindrical The first chamber is formed inside the cylindrical porous medium, the second chamber is formed outside the cylindrical porous medium, and one end of the cylindrical porous medium is blocked. It is characterized by that.
[0012]
As a preferred specific example of the present invention, if the second solution does not contain the target component, the concentration difference of the target component can be increased between the gas-dissolved water and the second solution, and the target component via the porous medium can be increased. Can be more effectively diffused. As an example, carbon dioxide gas, ammonia gas, hydrogen, and oxygen are used as the soluble gas containing the component of interest, and pure water and ultrapure water are used as the first solution and the second solution.
[0013]
As another specific example of the present invention, the average pore diameter of the porous medium is set to a fractional molecular weight of 3000 or more and 0.2 μm or less, more preferably a fractional molecular weight of 10,000 or more and 0.1 μm or less. Here, when the average pore diameter of the porous medium is less than the fractional molecular weight of 3000, and more preferably less than 10,000, there are cases where the diffusion rate of the component of interest is small and an effective transfer amount cannot be obtained. Further, when the average pore diameter of the porous medium exceeds 0.2 μm, and more preferably exceeds 0.1 μm, the amount of pressure transfer of the target component to the second solution side that occurs when the gas dissolved water containing the target component is replenished. Increases, the deviation from the control value increases, and the control accuracy may decrease.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a view showing an example of an apparatus for carrying out a gas-liquid mixing method using the dissolution diffusion method of the present invention. In the example shown in FIG. 1, a bottomed cylindrical ceramic membrane filter 3 is provided in a container 1 via a seal 2. The container 1 is provided with an inlet 4 and an outlet 5 of pure water that do not contain, for example, a very small amount of the target component such as carbonic acid and ammonia. A supply pipe 6 for supplying pure water into the container 1 is connected to the pure water inlet 4, and a pure water outlet 5 is used to discharge a mixed liquid in which a component of interest is injected into pure water. The discharge pipe 7 is connected, and the discharge pipe 7 has a specific resistance of the mixed liquid (basic control when mixing carbon dioxide gas and ammonia gas), oxidation-reduction potential (basic control when mixing hydrogen). A monitor 8 for measuring the dissolved oxygen concentration (basic control when mixing oxygen) and the like are provided.
[0015]
An inlet 9 is formed at the open end of the bottomed cylindrical ceramic membrane filter 3. The inlet 9 is provided with a supply pipe 10 for supplying a soluble gas containing a component of interest such as carbonic acid and ammonia, and the supply pipe 10 is further provided with a shutoff valve 11 and a pressure regulating valve 14. . In the apparatus shown in FIG. 1, a first chamber 12 for storing gas-dissolved water is formed inside the container 1 inside the ceramic membrane filter 3 and a second chamber for storing pure water outside the ceramic membrane filter 3. The chamber 13 is formed.
[0016]
In the example shown in FIG. 1, the ceramic membrane filter 3 serving as a porous medium has hydrophilicity because it is necessary to transfer the pure water in the second chamber 13 into the first chamber 12 in the first stage. The average pore size of the ceramic filter 3 as a porous medium should be a molecular weight cut-off of 3000 or more and 0.2 μm or less, preferably a narrower molecular weight cut-off of 10,000 or more and 0.1 μm or less. Is preferred. Here, as an example of the porous medium, the ceramic membrane filter 3 made of alumina, for example, has been exemplified, but any material having resistance to the liquid to be contacted can be used, and an organic membrane such as a hollow fiber membrane or a metal membrane is also suitable. Can be used for Further, ammonia, carbonic acid, sulfuric acid, hydrogen, and oxygen are exemplified as the component of interest, but ozone and the like can also be suitably used.
[0017]
FIG. 2 is a view showing another example of an apparatus for carrying out a gas-liquid mixing method using the dissolution diffusion method of the present invention. In the example shown in FIG. 2, the same members as those in the example shown in FIG. 2 is different from the example shown in FIG. 1 in that a cylindrical ceramic membrane filter 3 is used. Therefore, an outlet 21 is provided through the seal 2 at the end opposite to the side where the inlet 9 of the ceramic membrane filter 3 is provided, and a discharge pipe 22 and an opening / closing valve 23 are provided connected to the outlet 21. Yes. Also in the example shown in FIG. 2, when the on-off valve 23 is closed, the same operation as that of the bottomed cylindrical ceramic membrane filter 3 shown in FIG. 1 is performed.
[0018]
Next, a gas-liquid mixing method using the above-described apparatus will be described. First, pure water is circulated in the second chamber 13 from the inlet 4 toward the outlet 5 at a constant flow rate (the flow rate can be changed stepwise in the middle). This distribution of pure water is not essential, and it is not necessary to distribute it. However, it is possible to obtain a mixed liquid containing a trace amount of the component of interest by distributing it. As pure water circulates in the second chamber 13, the pure water is stored in the first chamber 12 through the ceramic membrane filter 3. Of course, solutions having different compositions can be stored in the first chamber 12 and the second chamber 13.
[0019]
In this state, by controlling the opening degree of the shut-off valve 11 and the pressure regulating valve 14, for example, carbon dioxide gas is pressurized and supplied to the pure water in the first chamber 12, and the pressurized carbon dioxide gas is supplied to the first water. Gas dissolved water is obtained in the first chamber 12 by dissolving in pure water in the first chamber 12. At this time, during the dissolution of carbon dioxide gas, the gas dissolved water is pressurized in the first chamber 12, and a part of the gas dissolved water is injected into the pure water side by press-fitting through the ceramic membrane filter 3. The Thereafter, when the dissolution of the carbon dioxide gas is completed and the pressure disappears, the gas-dissolved water in the first chamber 12 moves to the pure water side in the second chamber 13 by diffusion through the ceramic membrane filter 3 this time. . As for the above dissolution and diffusion, diffusion movement occurs simultaneously during dissolution, but dissolution may occur simultaneously during diffusion movement, or dissolution may not occur. Further, when carbon dioxide gas is introduced, a part of the gas-dissolved water containing carbon dioxide in the first chamber 12 is discharged by opening the on-off valve 23, thereby reducing pressure injection into the second chamber 13. The deviation from the concentration can also be reduced.
[0020]
The amount of gas-dissolved water to be diffused and injected is limited by the amount of gas-dissolved water stored in the first chamber 12. At this time, the pressure injection amount of the gas-dissolved water into the second solution when the soluble gas is supplied into the first chamber 12 under pressure, and the gas-dissolved water is diffused and injected into the second solution. It is preferable that the ratio with respect to the diffusion injection amount to be made is 1: 9 or more. The state of one cycle of this injection is shown in FIG.
[0021]
When the concentration of the gas-dissolved water in the first chamber 12 decreases due to diffusion, the component of interest is replenished by pressurizing and dissolving the soluble gas in the first chamber 12. In the replenishment of the target component, gas-dissolved water having a decreased concentration of the target component in the first chamber 12 is pressed into the pure water side in the second chamber 13 through the ceramic membrane filter 3 (FIG. 1). In the case of the apparatus), or the on-off valve 23 is opened and discharged from the discharge pipe 22 connected to the ceramic membrane filter 3 (in the case of the apparatus in FIG. 2). When discharged from the discharge pipe 22, pure water or gas-dissolved water permeates into the first chamber 12 from the second chamber 13.
[0022]
The supply of the soluble gas into the pure water or gas-dissolved water existing in the first chamber 12 of the ceramic membrane filter 3 is intermittently performed using the on-off valve 22 having an on-off speed of 0.1 seconds or less. The opening / closing speed of the valve affects the deviation from the control value when gas dissolved water is injected under pressure. If a valve with an opening / closing speed of 0.1 seconds or more is used, the control accuracy decreases. It is preferable to use one having a short speed. This open / close control is preferably configured to detect the concentration of the liquid mixture by a sensor provided in the discharge pipe 7 and to perform an open / close signal from a connected control device.
[0023]
FIG. 4 is a diagram showing the configuration of still another example of an apparatus for carrying out a gas-liquid mixing method using the dissolution and diffusion method of the present invention. In the example shown in FIG. 4, the same members as those in the examples shown in FIGS. 1 and 2 are denoted by the same reference numerals, and the description thereof is omitted. The example shown in FIG. 4 is different from the example shown in FIGS. 1 and 2 in that a flat sheet-shaped ceramic membrane filter 3 is used, and the first chamber is formed on one side of the flat sheet-shaped ceramic membrane filter 3. 12 is formed, and the second chamber 13 is formed on the other side.
[0024]
In the example shown in FIG. 4, the gas and liquid can be mixed basically in the same manner as in the examples shown in FIGS. 1 and 2, and the description thereof is omitted. In the example shown in FIG. 4, in order to increase the gas-liquid contact area, a certain amount of a hardly soluble gas such as nitrogen gas is introduced into the first chamber 12 for dissolving carbon dioxide gas in the first solution. The chamber 31 is formed and the carbon dioxide gas is supplied into the gas chamber 31, so that the carbon dioxide gas is dissolved in the ultrapure water in the first chamber 12.
[0025]
In the example shown in FIGS. 1 and 2, the bottomed cylinder that separates the gas-liquid inside or outside the bottomed cylindrical or cylindrical ceramic membrane filter 3 in order to increase the gas-liquid contact area. A gas chamber can be formed by inserting a cylindrical or cylindrical water-repellent film, and carbon dioxide can be dissolved in the first solution in the first chamber 12 by supplying carbon dioxide to the gas chamber. Needless to say.
[0026]
【Example】
Actually, carbonated water containing a small amount of carbonic acid was produced by injecting carbon dioxide gas into ultrapure water according to the gas-liquid mixing method using the dissolution and diffusion method of the present invention using the apparatus having the configuration shown in FIG. That is, as a porous medium, a tubular (outer diameter 10 mm × inner diameter 6 mm × length 200 mm) 0.1 μm ceramic membrane filter-3 was used, and carbon dioxide gas was injected into ultrapure water. The injection amount monitor-8 is a resistivity meter, and the injection amount setting value is 2 MΩ · cm as a specific resistance value. As shown in FIG. 5, when the monitor-8 shows a higher value than this, carbon dioxide is 1 It was supplied in pulses at seconds intervals. The inner side of the tubular ceramic membrane filter-3 is the first chamber 12 and the outer side is the second chamber 13, and by supplying ultrapure water of 18 MΩ · cm or more to the second chamber 13, the tubular ceramic membrane filter 3 is The first chamber 12 is filled with ultrapure water. Carbon dioxide gas can be supplied to the first chamber 12 at a pressure slightly higher than that of ultrapure water. An electromagnetic valve was used as the carbon dioxide gas supply cutoff valve 11.
[0027]
The results are shown in FIG. In FIG. 6, the flow rate of ultrapure water was changed from 10 L / min → 5 L / min → 1 L / min → 5 L / min → 10 L / min. In this flow rate range, the set value ± 50% was set as the upper and lower limit values. The injection amount could be controlled within the range. The amount of carbon dioxide required for injecting carbon dioxide into ultrapure water to make the specific resistance value 2 MΩ · cm is 0.27 ppm. Therefore, 2.7 mg / min of carbon dioxide must be injected into 10 L / min of ultrapure water. In the above embodiment, since data is collected every second, it is necessary to supply data at 45 μg / second. Since the carbon dioxide gas required for 1 MΩ · cm is about 0.9 ppm, in this embodiment, it can be injected in a range of 0.27 to 0.9 ppm with respect to a flow rate change of 10 to 1 L / min. .
[0028]
From either result, it can be seen that carbonated water containing a small amount of carbonic acid can be continuously obtained according to the present invention. In addition, although the above result is an example which used the ceramic membrane filter, the same result was able to be obtained even if it used the polysulfone hollow fiber membrane of the same average hole diameter.
[0029]
【The invention's effect】
As is clear from the above description, according to the present invention, the soluble gas containing the target component is once dissolved in the first solution, and the injection control from the obtained gas-dissolved water to the second solution is porous. By performing diffusion through a medium, a mixed solution containing a very small amount of the target component can be obtained.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of an apparatus for carrying out a gas-liquid mixing method using the dissolution diffusion method of the present invention.
FIG. 2 is a view showing another example of an apparatus for carrying out a gas-liquid mixing method using the dissolution diffusion method of the present invention.
FIG. 3 is a diagram showing one cycle of injection in the present invention.
FIG. 4 is a view showing still another example of an apparatus for carrying out a gas-liquid mixing method using the dissolution diffusion method of the present invention.
FIG. 5 is a diagram for explaining an example of control by a monitor in the embodiment of the present invention.
FIG. 6 is a graph showing an example of experimental results when carbon dioxide is injected into ultrapure water in the present invention.
[Explanation of symbols]
1 container, 2 seal, 3 ceramic membrane filter, 4 inlet, 5 outlet, 6 supply piping, 7 discharge piping, 8 monitor, 9 inlet, 10 supply piping, 11 shutoff valve, 12 first chamber, 13 first 2 chamber, 14 pressure regulating valve, 21 outlet, 22 discharge piping, 23 on-off valve, 31 gas chamber

Claims (8)

Dissolving the soluble gas of the component of interest in the first solution, bringing the obtained gas-dissolved water into contact with the second solution having a concentration of the component of interest lower than that of the gas-dissolved water through the porous medium, and diffusing When the gas-dissolved water is injected into the second solution by the above, a first chamber for storing the first solution is formed in one of the porous media, and the second solution for storing the second solution in the other of the porous media. In the first chamber, the soluble gas is dissolved in the first solution by injecting the first solution under pressure, and the obtained gas-dissolved water is passed through the porous medium. When injecting into the second solution in the second chamber, the pressure injection amount of the gas dissolved water into the second solution and the diffusion injection amount for diffusing the gas dissolved water into the second solution The gas-liquid mixing method using the dissolution diffusion method, wherein the ratio of the ratio is 1: 9 or more. The porous medium has a bottomed cylindrical shape with one end blocked, a first chamber is formed inside the bottomed cylindrical porous medium, and a second chamber is formed outside the bottomed cylindrical porous medium. A gas-liquid mixing method using the dissolution diffusion method according to claim 1, wherein a chamber is formed. The porous medium has a cylindrical shape, the first chamber is formed inside the cylindrical porous medium, the second chamber is formed outside the cylindrical porous medium, and the cylindrical porous A gas-liquid mixing method using the dissolution and diffusion method according to claim 1, wherein one end of the porous medium is closed. The porous medium has a flat sheet shape, a first chamber is formed on one side of the flat sheet-shaped porous medium, and a second chamber is formed on the other side of the flat sheet-shaped porous medium. A gas-liquid mixing method using the dissolution diffusion method according to claim 1. Dissolving the soluble gas of the component of interest in the first solution, bringing the obtained gas-dissolved water into contact with the second solution having a concentration of the component of interest lower than that of the gas-dissolved water through the porous medium, and diffusing When the gas-dissolved water is injected into the second solution by the above, a first chamber for storing the first solution is formed in one of the porous media, and the second solution for storing the second solution in the other of the porous media. In the first chamber, the soluble gas is dissolved in the first solution by injecting the first solution under pressure, and the obtained gas-dissolved water is passed through the porous medium. When injecting into the second solution in the second chamber , the pressure injection amount of the gas dissolved water into the second solution and the diffusion injection amount for diffusing the gas dissolved water into the second solution the ratio of 1: 9 or more and thereby, the porous medium has a bottomed cylindrical shape closes one end of a bottomed cylindrical shape The first chamber is formed, a bottomed cylindrical shape porous external dissolution diffusion method gas-liquid mixing method using, characterized in that the formation of the second chamber of the medium to the interior of the porous medium. Dissolving the soluble gas of the component of interest in the first solution, bringing the obtained gas-dissolved water into contact with the second solution having a concentration of the component of interest lower than that of the gas-dissolved water through the porous medium, and diffusing When the gas-dissolved water is injected into the second solution by the above, a first chamber for storing the first solution is formed in one of the porous media, and the second solution for storing the second solution in the other of the porous media. In the first chamber, the soluble gas is dissolved in the first solution by injecting the first solution under pressure, and the obtained gas-dissolved water is passed through the porous medium. When injecting into the second solution in the second chamber , the pressure injection amount of the gas dissolved water into the second solution and the diffusion injection amount for diffusing the gas dissolved water into the second solution the ratio of 1: 9 or more and then, the porous medium has a cylindrical shape, the shape of the first chamber into the interior of the porous medium cylindrical And, to form the second chamber to the exterior of the porous medium of a cylindrical shape, a cylindrical shape porous gas-liquid mixing method using a solution-diffusion process, characterized in that closes one end of the medium. The gas-liquid mixing method using the dissolution diffusion method according to any one of claims 1 to 6, wherein the second solution does not contain a component of interest. 7. The solution diffusion according to claim 1, wherein an average pore diameter of the porous medium is a fractional molecular weight of 3000 or more and 0.2 μm or less, preferably a fractional molecular weight of 10,000 or more and 0.1 μm or less. Gas-liquid mixing method using the method.

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