JP2013184072A - Gas dissolving method, and gas dissolving apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas dissolving method for dissolving predetermined gas in an aqueous solution containing a predetermined surfactant so as to exceed an equilibrium concentration proposed before, and a gas dissolving apparatus.SOLUTION: In a gas dissolving method, gas is mixed with an aqueous solution containing a surfactant to generate air bubbles, the gas in the air bubbles is dissolved in liquid films constituting the air bubbles, the air bubbles are defoamed to separate the liquid constituting the air bubbles and the gas is dissolved in the aqueous solution containing the surfactant. The gas dissolving apparatus is also provided.

Description

The present invention relates to a method and an apparatus for dissolving a gas such as ozone and oxygen in an aqueous solution containing a surfactant beyond the equilibrium concentration of gas and liquid which has been conventionally proposed.

ここで、Hはヘンリー定数（aｔｍ／ｍoｌ ｆｒａｃｔｉｏｎ）である。 When a solution containing a hardly soluble solute such as ozone or oxygen is in equilibrium with the gas partial pressure of the gas phase and the liquid phase, the partial pressure (P) of the solute such as ozone and oxygen in the gas phase is It is known that it is proportional to the concentration (X), and the relationship of the following formula 1 is established (Henry's law).

Here, H is the Henry constant (atm / mol fraction).

When the above Equation 1 is transformed, the following Equation 2 is obtained. The smaller the Henry constant, the higher the concentration of solutes such as ozone and oxygen in the solution.

Regarding the Henry's constant of ozone, many researchers have determined and reported the Henry's constant from experiments. Among them, the following equation of Roth & Sullivan reported in Non-Patent Document 1 below is most approximate.

Conventionally, the vapor-liquid equilibrium concentration has been calculated based on the above Equation 3, but no technology has been proposed for dissolving the gas phase solute in the liquid beyond the vapor-liquid equilibrium concentration. For example, in order to dissolve a gas phase solute in a predetermined aqueous solution, a packed tower, an aeration tank, an ejector, and the like have been conventionally used. In these methods, the volume ratio (L / G) of the liquid phase / gas phase is very large, that is, the contact area between the gas phase and the liquid phase is small, so the efficiency of dissolving the gas in the liquid is poor. In particular, when the gas is ozone gas, it is easily decomposed when it comes into contact with water. Therefore, it has been desired to develop a method for dissolving ozone gas at a high concentration in producing ozone water.

By the way, a technique for dissolving a gas in a predetermined aqueous solution has been put into practical use in many fields. For example, as in Patent Document 1, ozone gas is dissolved in soapy water and used as a washing solution for washing and washing. It has been proposed.

Since the cleaning solution supplied from the generating device of Patent Document 1 is always supplied as foam, there is a problem that the volume of the cleaning solution is large and the use is limited. Further, since the bubbles do not flow naturally, there is a problem that the bubbles are not easily replaced around the cells and the contaminants, and the cleaning ability and the sterilizing ability are inferior.

Utility model registration No. 3136370

Solubility of Ozone in Water, Industrial & Engineering Chemistry
Fundamentals, 1981, 20, pp. 137-140

It is an object of the present invention to provide a gas dissolving method and a gas dissolving apparatus for dissolving a predetermined gas in an aqueous solution containing a surfactant beyond an equilibrium concentration which has been conventionally proposed.

A gas is mixed with an aqueous solution containing a surfactant to generate bubbles, the gas in the bubbles is dissolved in a liquid film that forms the bubbles, and the bubbles are separated by separating the liquid from the bubbles. The above-mentioned problem is solved by a gas dissolving method characterized by dissolving the gas in an aqueous solution containing a surfactant.

An aqueous solution supply unit for supplying an aqueous solution containing a surfactant, a gas supply unit for supplying a gas, and an aqueous solution and a gas containing a surfactant supplied from the aqueous solution supply unit by connecting the aqueous solution supply unit and the gas supply unit A gas dissolving device comprising a bubble generator for mixing and foaming a gas supplied from a supply unit, wherein the bubble generator is generated by the bubble generation unit comprising a porous plate and the bubble generation unit. The above-described problem is solved by a gas dissolving device comprising a bubble diameter adjusting unit that adjusts the bubble diameter through the opened bubbles.

The bubble generator includes an aqueous solution supply pipe serving as an inflow path for an aqueous solution containing a surfactant supplied from an aqueous solution supply section, a gas supply pipe serving as an inflow path for a gas supplied from the gas supply section, and an aqueous solution supply. A bubble generating portion comprising a porous plate disposed downstream of the tube and the gas supply tube, a bubble diameter adjusting portion disposed downstream of the bubble generating portion, and a discharge pipe disposed downstream of the bubble diameter adjusting portion The aqueous solution containing the surfactant supplied from the aqueous solution supply pipe and the gas supplied from the gas supply pipe are preferably used in such a manner that they are mixed and foamed on the porous plate. be able to.

It may take time for the bubbles generated by the bubble generator to disappear. In that case, it is preferable that the gas dissolving apparatus includes a defoamer. The defoamer includes a receiving container for receiving bubbles supplied from the discharge pipe of the bubble generator, a suction fan disposed on the receiving container, a driving source for rotating the suction fan, and the receiving container and the suction fan. And a storage tank for storing the bubbles, the bubbles are sucked up by a suction fan, and are blown in the radial direction by the centrifugal force generated by the rotation of the suction fan and collide with the wall surface of the storage tank to eliminate the bubbles. Can be used for

According to the method and apparatus of the present invention, the contact area between an aqueous solution containing a surfactant and a gas is increased, that is, the volume ratio (L / G) of the liquid phase / gas phase is decreased, and the gas is interfaced. It becomes possible to dissolve in a high concentration in an aqueous solution containing an active agent. Moreover, according to the method and apparatus of the present invention, an aqueous solution containing a surfactant in which a gas is dissolved can be provided as a liquid instead of a foam.

It is the block diagram which showed the gas dissolving apparatus of this invention. It is a block diagram which shows another Example of the gas dissolving apparatus of this invention. It is sectional drawing of a bubble generator. It is sectional drawing of a defoamer. It is the graph which showed Example 1 and 2, and the disinfection ability of Comparative Examples 1 and 2.

In the present invention, a gas is mixed with an aqueous solution containing a surfactant (hereinafter referred to as a surfactant aqueous solution) to generate bubbles, and the gas in the bubbles is dissolved in a liquid film constituting the bubbles. The liquid which comprises a bubble is isolate | separated by defoaming, It is characterized by the above-mentioned. That is, in the method of the present invention, gas is encapsulated in bubbles, the contact area between the gas and the aqueous solution is increased, and the gas is dissolved in the liquid film constituting the bubbles. If the gas in the bubbles is dissolved in the liquid film constituting the bubbles and then the bubbles are recovered and defoamed, a surfactant aqueous solution in which the target gas is dissolved at a high concentration can be obtained. In other words, the formation of bubbles is only a means for dissolving the gas in the surfactant aqueous solution, and the bubbles may disappear after the gas is dissolved. The gas is dissolved at the interface between the bubble liquid film and the gas in the bubbles.

The present invention is a method for preparing a liquid surfactant aqueous solution, not bubbles comprising a surfactant aqueous solution. Therefore, in the present invention, after the gas is dissolved in the surfactant aqueous solution in the form of bubbles, the bubbles are always removed. Defoaming can be achieved by optimizing the type and concentration of the surfactant so that bubbles are easily lost or adjusting the inner diameter of the flow path of the bubble diameter adjustment section of the bubble generator described later. By doing so, the diameter of the bubbles may be increased. Alternatively, the bubbles may be forcibly extinguished using a defoamer as described later.

In order to efficiently dissolve the gas in the surfactant aqueous solution, it is necessary to once form bubbles and destroy the bubbles. Therefore, the concentration of the surfactant aqueous solution needs to be set to such a level that bubbles are generated when passing through a porous plate or the like. The specific concentration is adjusted according to the type of surfactant and the type of gas to be dissolved. The type of the surfactant used in the present invention is not particularly limited, and any surfactant other than those which react with the gas to be dissolved and impair the properties of the surfactant can be used. For example, a nonionic surfactant can be preferably used. The kind of gas dissolved in the surfactant aqueous solution is not particularly limited, and for example, ozone gas, oxygen gas, and the like can be suitably used.

The smaller the size of the bubbles, the greater the contact area between the gas and the surfactant aqueous solution and the easier the gas dissolves. However, since it takes time to defoam if the bubbles are excessively small, the diameter is preferably 0.1 to 2.0 mm, more preferably 0.2 to 1.6 mm.

In order to carry out the above-described gas dissolving method, for example, the gas dissolving apparatus shown in the block diagram of FIG. 1 may be used. As shown in the block diagram of FIG. 1, this apparatus connects an aqueous solution supply unit 1 that supplies a surfactant aqueous solution, a gas supply unit 2 that supplies gas, and the aqueous solution supply unit 1 and the gas supply unit 2. And a bubble generator 3 for mixing and foaming the surfactant aqueous solution and the gas supplied from them.

The aqueous solution supply unit 1 is a part that supplies a surfactant aqueous solution to the bubble generator 3. The configuration of the aqueous solution supply unit 1 is not particularly limited. For example, as illustrated in FIG. 1, a tank 11 that stores a surfactant aqueous solution, and a surfactant aqueous solution stored in the tank 11 is drawn into the bubble generator 3. The pump 12 is made up of.

The gas supply unit 2 is a part that supplies gas to the bubble generator 3. The configuration of the gas supply unit 2 is not particularly limited. For example, when ozone gas is dissolved in a surfactant aqueous solution as described later, the gas supply unit 2 includes a compressor 21 and an ozone generator 22 as shown in FIG. . In this case, the ozone generator 22 to be used is not particularly limited, and, for example, an ozone generator described in Table No. 2008-108331 may be used.

The bubble generator 3 is a device that mixes and foams the gas supplied from the gas supply unit 2 and the surfactant aqueous solution supplied from the aqueous solution supply unit 1. FIG. 3 shows a cross-sectional view of the bubble generator 3. The bubble generator 3 in FIG. 3 includes an aqueous solution supply pipe 31 serving as an inflow path for the surfactant aqueous solution supplied from the aqueous solution supply section 1 and a gas supply pipe 32 serving as an inflow path for the gas supplied from the gas supply section 2. A bubble generation unit 33 arranged downstream of the aqueous solution supply pipe 31 and the gas supply pipe 32, and a bubble diameter adjustment that adjusts the diameter of the bubbles generated downstream of the bubble generation unit 33 and generated by the bubble generation unit 33 And a discharge pipe 35 disposed downstream of the bubble diameter adjusting unit 35.

The bubble generator 3 of the present invention includes a bubble generation unit 33 made of a porous plate and a bubble diameter adjustment unit 34 that adjusts the diameter of the bubbles generated by the bubble generation unit 33. That is, the surfactant aqueous solution supplied from the aqueous solution supply pipe 31 and the gas supplied from the gas supply pipe 32 are mixed on the bubble generation unit 33 to generate bubbles including the gas. Bubbles are too large or bubbles are too small to easily disappear. Therefore, in the present invention, the generated bubbles are passed through the flow path 341 of the bubble diameter adjusting unit 34. At this time, if the inner diameter A of the flow path 341 is configured to be larger than the inner diameter B of the aqueous solution supply pipe 31 (that is, the flow path is a diameter expansion pipe), the pressure in the aqueous solution supply pipe is released, and the bubbles become larger and disappear quickly. It becomes possible to quickly generate ozone water having a high sterilizing ability. On the other hand, if the inner diameter A of the flow path 341 is configured to be smaller than the inner diameter B of the aqueous solution supply pipe 31 (that is, the flow path is a reduced diameter pipe), the pressure in the aqueous solution supply pipe is increased to reduce the bubble diameter, The volumetric ratio (L / G) of the liquid phase / gas phase can be reduced to increase the gas dissolution efficiency. The inner diameter of the channel 341 may be adjusted according to the concentration of the surfactant aqueous solution, the properties of the discharged bubbles, and the like.

If the bubble diameter adjustment part 34 is provided with the flow path 341 of the internal diameter expanded or contracted with respect to the internal diameter of the aqueous solution supply pipe 31, the outer shape and material will not be specifically limited. The bubble adjusting unit 34 in FIG. 3 is a molded body made of polyvinyl chloride, and the outer shape thereof is a columnar shape. A through hole is drilled along the center of the circle to form a bubble channel 341. The bubble diameter adjusting unit 34 is configured to be detachable, and the inner diameter of the flow path 341 can be changed by replacing the bubble diameter adjusting unit 34. A variable valve that can adjust the size of the inner diameter while flowing a fluid may be used. The bubble diameter adjusting unit 34 in FIG. 3 is sandwiched between two meshes 36.

It is preferable that the surfactant aqueous solution supplied from the aqueous solution supply pipe 31 and the gas supplied from the gas supply pipe 32 are mixed and foamed on the porous plate 33. If comprised in this way, it will become possible to mix surfactant aqueous solution and gas uniformly, and to make gas included in the bubble produced | generated by uniform density | concentration. The material of the porous plate is not particularly limited, and for example, a foamed resin (sponge) can be used.

In the case where it is difficult for the bubbles to disappear, the defoamer 4 may be provided in addition to the gas dissolving device of FIG. 1 (FIGS. 2 and 4). The defoamer 4 is a device that forcibly defoams bubbles generated by the bubble generator 3, and is used by being connected to the discharge pipe 35 of the bubble generator 3. The defoamer 4 is a receiving container 41 that receives bubbles (F) supplied from the discharge pipe 35 of the bubble generator 3, a suction fan 42 that is disposed on the receiving container 41, and a drive that rotates the suction fan 42. And 43 (electric motor). The bubbles are sucked up by the suction fan 42, are blown in the radial direction by the centrifugal force generated by the rotation of the suction fan 42, collide with the wall surface 45 of the storage tank 44 and disappear. The liquid that has collided with the wall surface 45 passes through the wall surface 45 and accumulates in the storage tank 44 to become ozone water (W). If such an apparatus is used, even if liquid is mixed in the bubbles discharged from the bubble generator 3, only the bubbles are sucked up and defoamed, and the defoamed surfactant aqueous solution is separated in the storage tank 44. be able to. In this case, since the liquid that has not become bubbles remains on the receiving container 41, the liquid that has not been dissolved in gas through the bubble liquid film is not mixed into the ozone water (W).

Next, the present invention will be described more specifically with reference to examples and comparative examples.
[Example 1]
Using the gas dissolving apparatus of FIG. 2 described above, ozone water was generated as follows. A polyoxyethylene alkyl ether aqueous solution adjusted to pH 7 at a temperature of 15 ° C. and 1.2% by weight from an aqueous solution supply pipe having an inner diameter of 4 mm at a flow rate of 30 ml / min is supplied to the porous plate of the bubble generator, and Ornit 1600 ppm of ozone gas generated by an ozonizer (SRG100) manufactured by Co., Ltd. was supplied to the porous plate of the bubble generator at a flow rate of 300 ml / min through a gas supply pipe having an inner diameter of 4 mm. The porous plate was made of a foamed melamine resin having an expansion ratio of 100 times and a thickness of 8 mm. The volume ratio (L / G) of the liquid phase / gas phase is 0.1. The inner diameter of the flow path of the bubble diameter adjusting unit was 1 mm.

Bubbles discharged from the discharge pipe of the bubble generator were supplied to the receiving container of the defoamer, and the suction fan was rotated at 3600 rpm to collide with the wall surface of the storage tank to eliminate bubbles, thereby obtaining ozone water. A part of the bubbles supplied to the receiving container was collected, and the diameter of the bubbles was measured and found to be 0.3 mm.

[Example 2]
Using the gas dissolving apparatus of FIG. 1 described above, ozone water was generated as follows. A polyoxyethylene alkyl ether aqueous solution adjusted to pH 7 at a temperature of 15 ° C. and 1.2% by weight from an aqueous solution supply pipe having an inner diameter of 4 mm at a flow rate of 30 ml / min is supplied to the porous plate of the bubble generator, and Ornit 1600 ppm of ozone gas generated by an ozonizer (SRG100) manufactured by Co., Ltd. was supplied to the porous plate of the bubble generator at a flow rate of 300 ml / min through a gas supply pipe having an inner diameter of 4 mm. The porous plate was made of a foamed melamine resin having a magnification of 100 times and a thickness of 8 mm. The volume ratio (L / G) of the liquid phase / gas phase is 0.1. The inner diameter of the flow path of the bubble diameter adjusting unit was 8 mm. The bubbles discharged from the discharge pipe of the bubble generator in FIG. 1 were not supplied to the defoamer, but only the bubbles were transferred to another container and allowed to stand for 1 minute, and waited for the bubbles to disappear naturally. It was 0.6 mm when the diameter of the bubble discharged from the discharge pipe was measured.

[Comparative Example 1]
Using the apparatus of FIG. 6 of Utility Model Registration No. 3136370, ozone bubbles were generated. As the surfactant aqueous solution, a polyoxyethylene alkyl ether aqueous solution adjusted to pH 7, temperature 15 ° C. and 1.2% by weight was used, and 1600 ppm of ozone gas was applied to the porous plate from the ozone generator at a flow rate of 300 ml / min. Supplied below. The porous plate was made of a foamed melamine resin having an expansion ratio of 100 times and a thickness of 8 mm. Ozone bubbles released from the soap bubble discharge tube were received in a container to obtain ozone bubbles.

The dissolved concentration (mg / l) of ozone water in Examples 1 and 2 was measured by the KI method shown below. The measurement results are shown in Table 1. The measurement was repeated three times and the ozone concentration was averaged.
[KI method]
1. An excess amount of potassium iodide (KI) and a predetermined amount of ozone water (sample water amount in Table 1) are placed in a flask.
About 5 ml of 10 wt% aqueous citric acid solution is added to the mixed aqueous solution of 2.1.
3. Add 100 g of pure starch (potato) 1 g of the starch aqueous solution prepared by heating to the mixed aqueous solution obtained in 2 to make the solution purple.
4. Add 0.0001 mol / l sodium thiosulfate dropwise to the mixed aqueous solution obtained in 3 and measure the amount (ml) of sodium thiosulfate solution required until the aqueous solution becomes colorless.
5. The ozone concentration is calculated by the following formula.
Ozone concentration (mg / l) = Dropped sodium thiosulfate (ml) x 0.0024 x 1000 / sample water (ml)

Table 1 shows the amount of water sampled in Examples 1 and 2, the sodium thiosulfate dropped, the ozone concentration calculated from them, and the Henry constant calculated from the ozone concentration. The ozone concentration of Example 1 was 3.16 mg / l, and the ozone concentration of Example 2 was 3.01 mg / l. Also in Comparative Example 1, an attempt was made to measure the ozone concentration by the KI method, but bubbles did not disappear, and it was impossible to determine the ozone concentration by titration.

ここで、Ｘは液体中のオゾンのモル分率である。 By the way, the ozone concentration in water (ozone equilibrium concentration in water, ppm) when ozone gas and water are in a gas-liquid equilibrium state is calculated by the following equation 4.

Here, X is the molar fraction of ozone in the liquid.

ここで、Ｐは気体中のオゾン分圧（ａｔｍ）、Ｈはヘンリー定数（aｔｍ／ｍoｌ ｆｒａｃｔｉｏｎ）である。
式５を変形すると次式６になる。

According to Henry's law, the relationship of the following formula 5 holds.

Here, P is the ozone partial pressure (atm) in the gas, and H is the Henry constant (atm / mol fraction).
When formula 5 is modified, formula 6 is obtained.

ここで、Ｐは気体中のオゾン分圧（ａｔｍ）、Ｐｔは気体圧力（ａｔｍ）、Ｃは気体中のオゾン濃度（ｇ／Ｎｍ^３）、Ｔは温度（Ｋ）である。 The ozone partial pressure P in the gas is obtained by the following equation 7.

Here, P is the ozone partial pressure (atm) in the gas, Pt is the gas pressure (atm), C is the ozone concentration (g / Nm ³ ) in the gas, and T is the temperature (K).

When Expression 4, Expression 6 and Expression 7 are put together, the following Expression 8 is obtained.

The Henry constant for ozone water is Roth &
The following equation 9 derived from experiments by Sullivan is the closest approximation.

When pH = 7 ([OH ⁻ ] = 10 ⁻⁷ ), 1 atm (Pt = 1 atm), water temperature 15 ° C. (K = 288.15 K, ozone gas concentration 1600 ppm (C = 3.429 g / Nm ³ )) The Henry constant is calculated to be about 4788 from Equation 9, and the equilibrium concentration of ozone gas is calculated to be about 0.94 mg / l from Equation 8. However, the ozone concentration actually measured by the KI method is shown in Table 1 below. As shown in Fig. 1, it was 3.16 mg / l, and in Example 2 it was 3.01 mg / l, indicating that ozone that is about three times the ozone concentration that is theoretically dissolved was dissolved in the surfactant aqueous solution. When the Henry's constant is calculated backward from the ozone concentration measured by the KI method, it becomes about 1424.31 in Example 1 and about 1495.28 in Example 2 as shown in Table 1. Conventionally, Henry's constant for water of ozone gas. Is the closest approximation to the value calculated from Equation 9, and the Henry's constant at ph7 and 15 ° C. is 4788 (see Table 2). It can be seen that the dissolution method of the invention has significantly improved ozone solubility compared to the conventional dissolution method.

By the way, when dissolving gases such as oxygen and ozone, an aeration tank is used almost without exception. In this case, microbubbles and nanobubbles having a diameter as small as possible are used to increase the gas-liquid contact area. Comparing the volume of the liquid phase and the gas phase at this time, the volume of the liquid phase is overwhelmingly large and the volume of the gas phase is extremely small. Therefore, in order to set the gas partial pressure in the liquid to a value close to saturation, it is necessary to keep the liquid in the tank for a long time and to aerate a gas such as ozone gas, and the liquid is discharged after entering the tank. It takes up to several hours. During this time, ozone gas decomposes. On the other hand, in the present invention, the time until the aqueous surfactant solution and ozone gas are mixed and foamed, defoamed to become ozone water can be suppressed to about several minutes. For this reason, even if ozone gas is decomposed, it is negligible, and this point seems to be a factor that is greatly different from the value obtained by the Roth & Sullivan equation taking into account the decomposition of ozone in the aeration tank.

Moreover, in the chemical engineering world, it is considered that the dissolution rate of hardly soluble gases such as oxygen and ozone in water is largely governed by the diffusion rate in the liquid film at the gas-liquid interface ( Chemical Engineering Handbook 7th Edition, 436 pages, 8.1 Basics of gas absorption, see e). In the method and apparatus of the present invention, ozone gas or the like is dissolved in an aqueous surfactant solution in the form of bubbles. In this case, the thickness of the liquid film constituting the bubbles (the thickness of the liquid-side boundary film) is about 30 μm, and both the front and back surfaces of the liquid film are in contact with a gas such as ozone gas. For this reason, the resistance of the liquid-side film is so small that it can be virtually ignored.

Next, the bactericidal ability of the ozone water of Examples 1 and 2 and the ozone foam of Comparative Example 1 were compared. In the test, a PET resin stick with Pseudomonas fluorescens attached was immersed in a beaker containing the ozone water of Example 1, Example 2 or the ozone bubbles of Comparative Example 1, and the relationship between the immersion time and the decrease in the number of bacteria. I investigated. For comparison, bactericidal ability was also examined for a 1.2% by weight polyoxyethylene alkyl ether aqueous solution (Comparative Example 2). The results are shown in the graph of FIG. The X-axis represents the elapsed time after immersion, the Y-axis represents the number of bacteria before immersion as N _0, and the number of bacteria after a predetermined time after immersion as N _c , and the decrease in the number of bacteria was expressed in logarithm.

As apparent from the graph of FIG. 5, the bactericidal effect was not observed in the 1.2 wt% polyoxyethylene alkyl ether aqueous solution (Comparative Example 2). In the ozone bubbles of Comparative Example 1, a decrease in the number of bacteria was observed until 2 minutes passed, but thereafter the decrease in the number of bacteria was stopped, and a sufficient bactericidal effect was not obtained. On the other hand, in Examples 1 and 2 in which bubbles containing ozone were defoamed into ozone water, a decrease in the number of bacteria was observed immediately after the start of immersion. When 4-6 minutes passed, the number of bacteria decreased to 1/10000 before the treatment, and the number of bacteria continued to decrease thereafter.

The ozone water produced by the method of the present invention exhibits a stronger bactericidal ability than Comparative Example 1. This is presumably because the ozone water produced by the method of the present invention was dissolved in an ozone concentration exceeding the equilibrium concentration that has been conventionally proposed. In addition, since the ozone bubbles around the cells do not flow naturally, it is difficult for bubbles to be exchanged around the cells, and it is considered that sufficient sterilization ability was not exhibited.

According to the present invention, ozone can be dissolved in a surfactant aqueous solution exceeding the conventionally proposed equilibrium concentration. Even with a relatively low concentration of ozone gas, sufficient concentration of ozone can be dissolved in the aqueous solution. Therefore, when generating ozone gas to be dissolved in the aqueous solution, concentrated oxygen is used or moisture that causes ozone decomposition is removed. No need to moisten.

DESCRIPTION OF SYMBOLS 1 Aqueous solution supply part 11 Tank 12 Pump 2 Gas supply part 21 Compressor 22 Ozone generator 3 Bubble generator 31 Aqueous solution supply pipe 32 Gas supply pipe 33 Bubble generation part 34 Bubble diameter adjustment part 35 Discharge pipe 36 Mesh 4 Defoamer 41 Acceptance Container 42 Suction fan 43 Driving source 44 Storage tank 45 Wall surface

Claims (4)

A gas is mixed with an aqueous solution containing a surfactant to generate bubbles, the gas in the bubbles is dissolved in a liquid film that forms the bubbles, and the bubbles are separated by separating the liquid from the bubbles. A gas dissolving method comprising dissolving the gas in an aqueous solution containing a surfactant. An aqueous solution supply unit for supplying an aqueous solution containing a surfactant, a gas supply unit for supplying a gas, and an aqueous solution and a gas containing a surfactant supplied from the aqueous solution supply unit by connecting the aqueous solution supply unit and the gas supply unit A gas dissolving device comprising a bubble generator for mixing and foaming a gas supplied from a supply unit,
The bubble generator includes a bubble generation unit made of a porous plate and a bubble diameter adjustment unit that adjusts the bubble diameter through the bubbles generated by the bubble generation unit. The bubble generator includes an aqueous solution supply pipe serving as an inflow path for an aqueous solution containing a surfactant supplied from an aqueous solution supply section, a gas supply pipe serving as an inflow path for a gas supplied from the gas supply section, an aqueous solution supply pipe, A bubble generation unit comprising a porous plate disposed downstream of the gas supply pipe, a bubble diameter adjustment unit disposed downstream of the bubble generation unit, and a discharge pipe disposed downstream of the bubble diameter adjustment unit ,
The gas dissolving apparatus according to claim 2, wherein the aqueous solution containing the surfactant supplied from the aqueous solution supply pipe and the gas supplied from the gas supply pipe are mixed and foamed on the porous plate. The gas dissolving device further comprises a defoamer connected to the gas generator,
The defoamer includes a receiving container for receiving bubbles supplied from a discharge pipe of a bubble generator, a suction fan disposed on the receiving container, a driving source for rotating the suction fan, and the receiving container and the suction fan. And a storage tank for containing
The gas dissolving device according to claim 2, wherein the bubbles are sucked up by a suction fan, blown in a radial direction by a centrifugal force generated by the rotation of the suction fan, and collided with a wall surface of a storage tank to be defoamed.

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