JP2002186839A - Gas dissolving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dissolve O3 in water without generating bubbles. SOLUTION: A gas dissolving pipe 30a comprising a porous polytetrafluoroethylen polymer and having an air permeability of 0.5×103-105 sec/100 cc, a vacant pore ratio of 25-50%, and a circumferential tensile strength of 450 kgf/cm2 or more is accommodated in a container 2, water is fed into the gas dissolving pipe 30a and O3 is fed to a space 5 between an outer peripheral surface of the gas dissolving pipe 30a and an inner peripheral surface of the container. A water pressure is 2-10 kgf/cm2 and a pressure of the O3 gas is less than the water pressure. A differential pressure (ΔP=Pw-Pg) of the pressure Pw of water and the pressure Pg of the gas is less than 5 kgf/cm2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas dissolving apparatus for dissolving a gas in a liquid without generating bubbles.

[0002]

Heretofore, and Cl ₂ gas is used to sterilize the tap water water supply and instead of Cl _2,
Ozone O ₃ gas is supplied by bubbling to further improve the sterilization performance. In such prior art,
O ₃ gas bubbles remain in the tap water, and tap water containing such O ₃ gas is supplied, which adversely affects the human body.

[0003]

The object of the present invention is to provide an O ₃
It is an object of the present invention to provide a gas dissolving device which can dissolve gas without bubbling.

[0004]

The present invention comprises a porous polytetrafluoroethylene polymer having an air permeability of 0.5 ×.
10 ³ -10 ⁵ sec / 100 cc, porosity 25-50
%, A gas dissolving tube 30a having a circumferential tensile strength of 450 kgf / cm ² or more, a container 2 for accommodating the gas dissolving tube, and a liquid in which the gas is to be dissolved is supplied into the gas dissolving tube. A gas source connected to the container and supplying a gas to be dissolved having a pressure less than the pressure of the liquid in the space 5 between the outer peripheral surface of the gas dissolving tube and the inner peripheral surface of the container; And 3) a gas dissolving apparatus.

According to the present invention, a liquid such as water is supplied into the gas dissolving tube 30a, and the space 5 between the outer peripheral surface of the gas dissolving tube and the inner peripheral surface of the container is filled with the liquid. The gas to be dissolved is supplied at a low pressure, below the pressure of the liquid. In this way, the gas can be dissolved in the liquid inside through the tube wall of the gas dissolving tube, and there is no possibility that gas bubbles are generated in the liquid.

The gas dissolving tube is made of a porous polytetrafluoroethylene polymer (abbreviated as PTFE). This PT
FE is not only a tetrafluoroethylene homopolymer but also a so-called modified polytetrafluoroethylene obtained by copolymerizing 2% by weight or less (particularly preferably 0.01 to 1% by weight) of a copolymerizable monomer. including. Examples of the copolymerized monomer include perfluoroalkyl vinyl ether, chlorotrifluoroethylene, and hexafluoropropylene. In the present invention, this P
It is preferable that TFE is extruded in the form of a paste, and the obtained tube is sintered and then used as a raw material tube.

In a state where the raw material tube is heated to a temperature higher than the softening point and lower than the melting point, for example, at a heating temperature of 90 to 320 ° C., a fluid such as a compressed gas such as compressed air is filled therein. Supply at a pressure of ² to 10 kgf / cm ² ,
It thermally expands in the radial direction and the longitudinal direction, and is cooled in this thermally expanded state. Thus, the gas dissolving tube of the present invention is manufactured. The gas permeability of the gas melting tube is 0.5 × 10 ³ to 10 ⁵ s
ec / 100 cc. Air permeability is also called air permeability or Gurley number, and is based on Japanese Industrial Standard JIS P-8117-
It can be measured according to 1980. Air permeability 0.5
If it is less than × 10 ³ sec / 100 cc, production is difficult, and if it is more than 10 ⁵ sec / 100 cc, it takes too much time to dissolve the gas, and it becomes difficult to dissolve the gas in the liquid.

[0008] The porosity is determined to be about 25 to 50%. Porosity is also called porosity. Based on the density ρ1 of the raw material tube before thermal expansion at the time of production and the density ρ2 of the gas dissolving tube which has become a product after thermal expansion of the raw material tube, the following equation 1 is obtained.
From this, the porosity A can be calculated and calculated. A = (ρ1-ρ2) × 100 / ρ1 (1)

If the porosity is less than 25%, the air permeability is 0.5
It becomes less than × 10 ⁵ sec / 100 cc. When the porosity is 50% or more, the air permeability is 0.5 × 10 ³ sec /
100cc or more.

Further, the gas dissolving tube of the present invention is selected to have a tensile strength in the circumferential direction of 450 kgf / m ² or more. Is obtained. Therefore, a reinforcing material surrounding the outside of the gas dissolving tube is not required, and the configuration is simplified, and the productivity is improved.

Further, the present invention is characterized in that the gas dissolving portion of the gas dissolving tube has an outer diameter of about 10 to 50 mmφ and a thickness of about 25 to 200 μm.

According to the present invention, the outer diameter of the gas dissolving tube is made larger than that of the prior art, ie, about 10 to 50 m.
By setting the diameter to mφ, the pressure loss of the liquid supplied into the gas melting tube can be reduced. Therefore, the labor of the pump for supplying the liquid can be reduced. The thickness of the outer wall of the gas dissolving portion of the gas dissolving tube, which is the thickness of the outer wall, is about 25 to 200 μm, whereby the above-described air permeability, porosity, and circumferential tensile strength are realized.

Further, the present invention is characterized in that a plurality of gas dissolving tubes are connected in series in a container.

Further, the present invention is characterized in that a plurality of gas dissolving tubes are connected in parallel in a container.

According to the present invention, a plurality of gas melting tubes are connected in series in a container as shown in FIG. 4 or in parallel as shown in FIG. The series connection ensures gas dissolution. The parallel connection allows for gas dissolution of large or large flows of liquid. In another embodiment of the present invention, the gas dissolving tube may be configured by combining respective connections in series and parallel.

The present invention comprises a porous polytetrafluoroethylene polymer having an air permeability of 0.5 × 10 ³ to 10 ⁵ sec.
c / 100 cc, a porosity of 25 to 50%, and a gas melting member 4 having a circumferential tensile strength of 450 kgf / cm ² or more
6, a container 47 for storing a gas-dissolving member, forming a liquid space 48 facing one surface of the gas-dissolving member, and forming a gas space 49 facing the other surface of the gas-dissolving member;
A liquid source 8 for supplying a liquid in which a gas is to be dissolved into the liquid space 48, and a gas source 3 for supplying a gas to be dissolved having a pressure less than the pressure of the liquid in the gas space 49. It is a gas dissolving device characterized by including.

According to the present invention, the gas dissolving member 46
As shown in FIG. 6, for example, the gas dissolving tube is formed in a film shape developed in the circumferential direction, and the space in the container is formed by the gas dissolving member into the liquid space 48 and the gas space 4.
9 is divided. The gas in the gas space 49 permeates and dissolves in the liquid in the liquid space 48 in the film thickness direction of the gas dissolving member 46.

In the present invention, the pressure of the liquid is 2 to 10 kg.
f / cm ² .

The present invention also provides that the pressure of the liquid is 5 to 10
kgf / cm ² .

According to the present invention, by setting the pressure of the liquid within the above range, the liquid does not flow out or seeps through the gas dissolving pipe or the gas dissolving member in the thickness direction. Moreover, the pressure of the liquid can be made relatively high in the above range. Therefore, the gas can be dissolved in the liquid at a high concentration.

Further, the present invention is characterized in that the pressure difference ΔP between the pressure of the liquid and the pressure of the gas is less than 5 kgf / cm ² .

According to the present invention, the pressure difference (ΔP = Pw−Pg) between the liquid pressure Pw and the gas pressure Pg is 5 kgf /
cm ² (ΔP <5 kgf / cm ² ), whereby the gas can be dissolved in the liquid at a high concentration, and the gas and the liquid between the surfaces of the gas-dissolving tube or the gas-dissolving member can be mixed with each other. Reduce the pressure difference ΔP, and
a or the gas melting member 46 can be prevented from being damaged by the pressure difference.

Further, the present invention is characterized in that the liquid is water and the gas is O ₃ .

According to the present invention, O ₃ can be dissolved in water. Therefore, Cl for sterilization of waterworks etc.
Disinfection can be performed more effectively by using O ₃ gas instead of the _two gases.

In the technical field of semiconductor manufacturing, O ₃ gas is dissolved in ultrapure water, and the water in which such O ₃ gas is dissolved is brought into contact with, for example, a Si semiconductor substrate, and the surface of the Si semiconductor substrate is coated with SiO _2. It is possible to easily form a film.

Further, according to the present invention, the liquid contains bacteria to be sterilized such as bacteria, and by dissolving O ₃ gas as described above according to the present invention, the liquid to be treated can be effectively sterilized. Can be.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a cross-sectional view showing an entire configuration of an embodiment of the present invention. The gas dissolving apparatus 1 basically includes a gas dissolving tube 30a and a gas dissolving tube 3a.
0a, a liquid source 8 for supplying water as a liquid in which O ₃ is to be dissolved, and a gas source 3 for supplying O ₃ connected to the container 2 inside the gas dissolving pipe 30a. And The pipeline 4 connected to the gas source 3 communicates with the space 5 between the outer peripheral surface of the gas dissolving tube 30a and the inner peripheral surface of the container 2, and reduces the pressure Pg of the O ₃ gas to the gas dissolving tube 30a. (Pw> Pg). Pressure Pw of water supplied from liquid source 8 to gas dissolving tube 30a
Is, for example, ² to 10 kgf / cm ² , preferably 5 to 10 kgf / cm ² . The pressure difference ΔP between the water pressure Pw and the O ₃ gas pressure Pg is, for example, 5 kgf / cm
² (ΔP = Pw−Pg <5 kgf / cm ² ).
The pressure Pg of the O ₃ gas may be, for example, less than ² kgf / cm ² . Thus, the water in the gas dissolving tube 30a does not leak into the space 5 and does not seep out,
Further, the O ₃ gas does not enter the gas dissolving tube 30a in a bubble state.

Water is supplied from a liquid source 8 including a pump to one of the pair of connecting pipes 6 and 7 protruding inward of the container 2 to the gas dissolving pipe 30a. Water from which the O ₃ gas is dissolved is discharged from the other connecting pipe 7.
Each end 15, 16 in both longitudinal directions of the gas melting tube 30a
Are detachably connected in the space 5 of the connecting pipes 6, 7 by pipe joints 17, 18. The pipe 4 and the connection pipe 6 are inserted through the plug 13 in a gas-tight manner, and are detachably fitted to one end of the container 2. The other connecting pipe 7 is inserted into the plug 14 in an airtight manner, and is fitted to the other of the container 2. The container 2 may have a right cylindrical shape.

FIG. 2 is a sectional view of the gas dissolving tube 30a. The gas dissolving tube 30a has both ends 15, 16 in the longitudinal direction (vertical direction in FIGS. 1 and 2) smaller in diameter than the gas dissolving portion 19. This gas dissolving tube 30a
Consists of porous PTFE. The gas dissolving portion 19 has an air permeability of 0.5 × 10 ³ to 10 ⁵ sec / 100 cc, a porosity of 25 to 50%, and a circumferential tensile strength of 450 kgf / cm ² or more. Gas melting part 19
Has an outer diameter of about 10 to 50 mmφ, for example, about 20 mm.
mmφ. The thickness of the outer wall of the gas melting portion 19 is about 25 to 200 μm.

The tensile Young's modulus of the gas dissolving tube 30a is 8
000 kgf / cm ² or more. Gas melting tube 30a
The pore diameter of the micropores existing in the gas dissolving portion 19 of FIG.
05μm or less, for example, 0.01 to 0.05 [mu] m, the pores of about 2 per surface 1 cm ² of the tube 30a
There are 100 million holes. Both ends 15, 16 of gas melting tube
For example, is partially immersed in a molten salt or oil at 327 ° C. to 380 ° C. to be thermally shrunk and returned to the original size. In FIG. 2, the length L1 of the gas dissolving portion 19 of the gas dissolving tube 30a is 250 mm, and the heat-shrinkable small-diameter end portion 15,
Each length L2 = L3 = 50 mm of the 16
(= L1 + L2 + L3) = 350 mm.

By reducing the diameter of the end 15 of the gas dissolving tube 30a as described above, the thickness of the end 15 increases. The end portion 15 having the increased thickness is sandwiched in the pipe joint 17, and airtightness is reliably achieved by the flared connection. Another fitting 18 is configured similarly to the fitting 17.

FIG. 3 is a graph showing the experimental results of the present inventor. The water pressure resistance corresponding to the diameter of the fine hole which is the through hole formed in the gas melting portion 19 of the gas melting tube 30a is inversely proportional.
When the thickness is less than 05 μm, the water pressure resistance is ² to 10 kgf / cm ² , which is sufficiently high.

FIG. 4 is a partial sectional view of another embodiment of the present invention. This embodiment is similar to the above-described embodiment, and corresponding portions are denoted by the same reference numerals. In this embodiment, a plurality (for example, three) of gas dissolving tubes 30 are used.
b, 30c and 30d are connected in series. The ends of these gas melting tubes 30b, 30c, 30d are detachably connected to each other by pipe joints 28a, 28b. The pipe joints 28a and 28b may have the same configuration as the pipe joints 17 and 18 described above.

FIG. 5 is a sectional view of still another embodiment of the present invention. This embodiment is similar to the above-described embodiment, and corresponding parts are denoted by the same reference numerals. In this embodiment, the gas dissolving tubes 30e, 30f, 30g are:
They are connected in parallel and connected to the branched connection pipes 6,7.
In another embodiment of the present invention, a plurality of gas dissolving tubes connected in series (for example, three sets) are connected in parallel, and connected to the connection tubes 6 and 7.

FIG. 6 is a sectional view showing the entire structure of another embodiment of the present invention. The gas dissolving device 45 basically includes a gas dissolving member 46 as a film, a container 47 for accommodating the gas dissolving member 46, and a first space 48 partitioned in the container 47 by the gas dissolving member 46. To
A liquid source 8 for supplying a liquid which is water in which the gas is to be dissolved;
Another space 49 partitioned by the gas dissolving member 46 of the container 47 includes the gas source 3 for supplying O ₃ gas to be dissolved in water. The gas-dissolving member 46 may have a configuration in which the above-described gas-dissolving tube 30a is divided along the longitudinal axis and developed in the circumferential direction. Other configurations are the same as those of the above-described embodiment.

In another embodiment of the present invention, other types of liquids may be used instead of water. In addition, other types of gases may be used instead of the O ₃ gas.

[0037]

According to the present invention, the gas dissolving pipe 30a or the gas dissolving member 46 is used to immerse O in a liquid such as water.
Gases such as ₃ can be easily dissolved, and no gas is contained in the liquid. Moreover, such a configuration is simple, excellent in productivity, and furthermore, in use,
Has sufficient strength.

Further, according to the present invention, the outer diameter of the gas dissolving portion 19 of the gas dissolving tube, that is, the portion other than the heat-shrinked end portion, is made relatively large, so that its thickness is made small. Thus, the pressure loss of the liquid in which the gas is to be dissolved can be reduced, the pumping pressure of the pump can be reduced, and the pump can be downsized.

According to the present invention, a plurality of gas dissolving tubes can be connected in series as shown in FIG. 4 to efficiently dissolve the gas sufficiently in the liquid. By connecting the pipes in parallel as shown in FIG. 5, the gas can be dissolved in a large amount or a large amount of liquid.

According to the present invention, the gas can be dissolved without generating bubbles in the liquid.

According to the present invention, the gas can be dissolved in the liquid without leaking or seeping out the liquid from the gas dissolving tube 30a or the gas dissolving member 46.

According to the present invention, the pressure difference ΔP between the pressure of the liquid and the pressure of the gas is set to less than 5 kgf / cm ² , so that the gas can be dissolved in the liquid and the gas dissolving pipe 30a or the gas dissolving Undesirable stress does not act in the thickness direction of the member 46, and breakage can be prevented.

According to the present invention, water in which O ₃ is dissolved can be easily obtained, and the present invention can be widely applied in the field of water sterilization and semiconductors, as well as other technical fields.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an entire configuration of an embodiment of the present invention.

FIG. 2 is a sectional view of a gas dissolving tube 30a.

FIG. 3 is a graph showing experimental results of the present inventor.

FIG. 4 is a partial cross-sectional view of another embodiment of the present invention.

FIG. 5 is a sectional view of still another embodiment of the present invention.

FIG. 6 is a cross-sectional view showing the overall configuration of another embodiment of the present invention.

[Explanation of symbols]

 1,45 gas melting device 2,47 container 3 gas source 5; 48,49 space 8 liquid source 30a-30g gas melting tube 46 gas melting member

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C02F 1/50 520 C02F 1/50 520B 531 531R 540 540A 1/78 1/78

Claims (9)

[Claims] 1. A porous polytetrafluoroethylene polymer having an air permeability of 0.5 × 10 ³ to 10 ⁵ sec / 10.
0 cc, porosity 25-50%, circumferential tensile strength 45
A gas dissolving tube 30a of 0 kgf / cm ² or more, a container 2 for accommodating the gas dissolving tube, a liquid source 8 for supplying a liquid in which gas is to be dissolved into the gas dissolving tube, A gas source 3 for supplying a gas to be dissolved having a pressure less than the pressure of the liquid in a space 5 connected between the outer peripheral surface of the gas dissolving tube and the inner peripheral surface of the container. Gas dissolving equipment. 2. An outer diameter of a gas dissolving portion of a gas dissolving tube is about 10 to 50 mmφ, and a thickness thereof is about 25 to 2
The gas dissolving apparatus according to claim 1, wherein the diameter of the gas dissolving apparatus is 00 µm. 3. The gas dissolving apparatus according to claim 1, wherein a plurality of gas dissolving tubes are connected in series in the container. 4. The gas dissolving apparatus according to claim 1, wherein a plurality of gas dissolving tubes are connected in parallel in the container. 5. An air permeability of 0.5 × 10 ³ to 10 ⁵ sec / 10 which is made of a porous polytetrafluoroethylene polymer.
0 cc, porosity 25-50%, circumferential tensile strength 45
A gas dissolving member 46 of 0 kgf / cm ² or more and a gas dissolving member are housed therein to form a liquid space 48 facing one surface of the gas dissolving member, and a gas dissolving member 48 facing the other surface of the gas dissolving member. A container 47 forming a space 49; a liquid source 8 for supplying a liquid in which the gas is to be dissolved in the liquid space 48; and a liquid having a pressure less than the pressure of the liquid in the gas space 49. A gas source for supplying a gas. 6. The gas dissolving apparatus according to claim 1, wherein the pressure of the liquid is ² to 10 kgf / cm ² . 7. The pressure of the liquid is 5 to 10 kgf / cm.
Gas dissolution apparatus according to claim 6, characterized in that the ^2. 8. The gas dissolving apparatus according to claim 1, wherein a pressure difference ΔP between the pressure of the liquid and the pressure of the gas is less than 5 kgf / cm ² . 9. The method according to claim 9, wherein the liquid is water and the gas is O ₃
The gas dissolving apparatus according to any one of claims 1 to 8, wherein