WO1997048640A1

WO1997048640A1 - Moisture generation method and moisture generator

Info

Publication number: WO1997048640A1
Application number: PCT/JP1997/002131
Authority: WO
Inventors: Tadahiro Ohmi; Takahisa Nitta
Original assignee: Ultraclean Technology Research Institute
Priority date: 1996-06-20
Filing date: 1997-06-20
Publication date: 1997-12-24
Also published as: JP3952087B2

Abstract

A moisture generation method and a moisture generator can efficiently generate high concentration moisture having high reactivity. A method of generating a moisture by reacting hydrogen and oxygen, comprises a mixed gas preparation step a1 of mixing hydrogen and oxygen to prepare a first mixed gas without diluting them with an inert gas, and a moisture generation step b1 of introducing the first mixed gas into a reaction tube incorporating a material having a catalytic function of reacting hydrogen with oxygen or made of such a material, and reacting hydrogen and oxygen inside the reaction tube to generate moisture. The moisture generator comprises a hydrogen source, means for controlling the hydrogen flow rate, an oxygen source, means for controlling the oxygen flow rate, a first mixing portion for mixing hydrogen and oxygen to prepare a first mixed gas, a reaction tube incorporating a material having a catalytic function of reacting hydrogen and oxygen constituting the first mixed gas or made of such a material, and means for introducing the first mixed gas into the reaction tube from the first mixing portion.

Description

Description Water generation method and water generation device

5 technical fields

The present invention relates to a moisture generation method and a moisture generation device. More specifically, the present invention relates to a water generation method and a water generation apparatus, which have a high reaction rate for generating water from hydrogen and oxygen and have a small deterioration in the reaction rate.

10 background technology

(1) Diffusion tube (diffusion) type water generation method

Water is introduced into a resin tube through which water molecules permeate, and is diffused at a given temperature using the fact that the speed at which water molecules permeate the resin film toward the outside is constant. In this method, water is mixed with the inert gas flowing outside the diffusion tube to generate water. The control of the water concentration is determined by the temperature of the diffusion tube and the flow rate of the inert gas. Figure 5 shows a schematic diagram of the device.

(2) Water generation method using vapor pressure of water

The sealed container (water and outside air) containing water is kept at a constant temperature, and the inert gas is passed through the gas phase or water of the container, and the vapor pressure of water at the desired temperature. This is a method for obtaining an inert gas containing water corresponding to the above. The control of moisture concentration is determined by the temperature (steam pressure) inside the closed vessel. Figure 6 shows a schematic diagram of the device.

(3) Water generation method for diluting the standard gas filled in the cylinder

A method in which a standard gas of water filled in a cylinder is diluted with an inert gas at an arbitrary dilution rate to generate an arbitrary concentration of water. Figure 7 shows a schematic diagram of the device.

25 (4) A method in which hydrogen and oxygen gas are burned at a temperature of 700 ° C or more in a quartz furnace to generate moisture. Figure 8 shows a schematic diagram of the device.

However, the above prior art has the following problems.

(a> In the technology of (1) above, it is not possible to obtain a gas mixture of ultra-high purity water because hydrocarbon-based impurities are mixed from the diffusion tube.

0 (b) The above technology (1>) controls low water concentration of ppb and ppt level I can't. Water released from the diffusion tube is always generated at ppb level. (c) The technique (i) has poor response to moisture concentration.

(cl) The technology of (1) above has low moisture concentration reliability. Because the diffusion tube changes over time.

(e) Maintenance and handling of the above techniques (〗) and (2) are difficult. Because accurate temperature control is required.

(f) The technique of (2) requires a long time to start up the device.

(«·) The technology of the above (2) has low reliability of moisture concentration.

(h) The technique (2) requires a long time for calibration.

(i> The technology of ('3) above has low reliability of moisture concentration because there is no standard gas with accurate moisture concentration.)

1) It is difficult for the technology of (3) to generate high concentration and large amount of water.

(k> The technology of (4) above directly burns hydrogen and oxygen, so the temperature is close to 2000 ° C. The material of the outlet is limited to power and SiC, and it is difficult to make. A dust occurs.

(1) The above technology (1) requires equipment that can handle high-temperature processes of 700 ° C or higher.

As a method for solving such a problem, a technique disclosed in Japanese Patent Application Laid-Open No. Hei 6-115903, that is, a first mixed gas is prepared by mixing hydrogen, oxygen and an inert gas The first mixed gas is introduced into a reaction tube made of a material having a catalytic action capable of radicalizing hydrogen and oxygen by mixing the first mixed gas and heating the inside of the reaction furnace tube. A water generation method characterized by comprising a water generation step of reacting hydrogen and oxygen contained in the mixed gas to generate water. Figure 9 shows a schematic diagram of the device.

According to this technology, it is possible to obtain a large amount of accurate concentration and ultra-high clean water mixed gas in a wide range from low concentration of PP t and ppb to high concentration of% order. It has been reported early on that a water generation method that is easy to maintain can be provided.

However, in the technique of the publication, since inert gas is mixed in addition to hydrogen and oxygen, the utilization efficiency of hydrogen and oxygen introduced to generate moisture, that is, (from the amount of introduced hydrogen and oxygen, Because the ratio of (actually generated water) to (the amount of water that can be generated) is low (hereinafter referred to as the reaction rate), a high range of water can be obtained, for example, even in% order. It was difficult. In addition, it was not possible to achieve water in a high concentration region close to 100%

In addition, a large amount of mixed gas must be introduced to increase the amount of generated moisture. Therefore, it was necessary to use a container with a large internal volume as a container for the water generation process. As a result, it was difficult to control the manufacturing process, and there were problems with its stability.

An object of the present invention is to provide a water generating method and a water generating apparatus which have a high reaction rate and can efficiently generate a high concentration of water. Disclosure of the invention

The method for producing moisture according to the present invention is a method for producing moisture by reacting hydrogen and oxygen, wherein a mixed gas producing step a1 of producing a first mixed gas by mixing hydrogen and oxygen without dilution with an inert gas. ,

A material having a catalytic action for reacting the hydrogen and the oxygen is incorporated therein, or the first mixed gas is introduced into a reaction tube made of the material, and the hydrogen and the oxygen are mixed in the reaction tube. And a water generating step b1 for generating water by reacting. In the present invention, hydrogen and oxygen are mixed without being diluted with an inert gas to form a first mixed gas. In the water generation step b b, water is generated from the first mixed gas. Moisture can be generated at a higher reaction rate than in the case of containing water.

Further, by using a gas having a hydrogen to oxygen ratio of 2 (molar ratio) or more as the first mixed gas, a reaction can be achieved at a reaction rate of about 100%.

Further, the second mixed gas generated in the moisture generation step b1 is mixed with oxygen so that excess hydrogen is contained therein and the ratio of oxygen to hydrogen contained in the second mixed gas becomes 0.5 or more. (Third mixed gas producing step a2) The third mixed gas is introduced into a second reaction tube containing a material having a catalytic action for reacting hydrogen and oxygen, or into a second reaction tube made of the material. By reacting hydrogen and oxygen in the second reaction tube to generate water, it is possible to generate only water containing no hydrogen or water containing oxygen. Therefore, the gas generated in the second reaction tube can be introduced into an apparatus for forming an oxide film such as a semiconductor. Further, the impurity concentration of the hydrogen and the oxygen is preferably 10 Pppb or less, and more preferably 10 Ppt or less.

Here, the impurities are at least one of nitrogen, carbon dioxide, and organic gas. These impurities When introduced directly into a use point (for example, an apparatus for forming an oxide film of a semiconductor), not only causes contamination of semiconductors and the like, but also causes a reduction in the reaction rate between oxygen and hydrogen.

It is preferable to heat both the first reaction tube and the second reaction tube to 300 ° C. or more, more preferably to 400 ° C. or more. It is more preferred to heat to 500 ° C. or higher. However, since the first reaction tube contains more than 4% of hydrogen, if it exceeds 550 ° C, there is a possibility of explosion of hydrogen, so the temperature is preferably 550 ° C or less. In the case of the second reaction tube, heating up to about 600 ° C. is possible because of a low hydrogen content.

The moisture generating device of the present invention,

A hydrogen source,

10 means for controlling the hydrogen flow rate;

An oxygen source,

Means for controlling the oxygen flow rate;

A first mixing section for mixing the hydrogen and the oxygen to form a first mixed gas, and a material having a catalytic action for causing the hydrogen and the oxygen constituting the first mixed gas to react with each other; A reaction tube containing or made of the material;

Means for introducing the first mixed gas from the first mixing section into the reaction tube;

It is characterized by having.

In particular, a second mixing section for mixing oxygen with the second mixed gas from the reaction tube downstream of the reaction tube to produce a third mixed gas;

A second reaction tube containing a material having a catalytic action for reacting hydrogen and oxygen among the components constituting the third mixed gas or comprising the material;

And means for introducing the third mixed gas from the second mixing section into the second reaction tube. 5 Brief description of the drawings

FIG. 1 is a schematic diagram showing an example of the water generation method according to the present invention.

FIG. 2 is a schematic diagram showing another example of the water generation method according to the present invention.

FIG. 3 is a graph showing the result of examining the relationship between the argon gas dilution rate and the reaction rate according to Example 1.

30 FIG. 4 shows the result of examining the relationship between the ratio of hydrogen to oxygen and the reaction rate according to Example 2. It is a graph.

FIG. 5 is a schematic diagram showing an example of a conventional water generation method.

FIG. 6 is a schematic diagram showing another example of the conventional water generation method.

FIG. 7 is a schematic diagram showing another example of the conventional moisture generation method.

FIG. 8 is a schematic diagram showing another example of the conventional moisture generation method.

FIG. 9 is a schematic view showing another example of the conventional moisture generation method.

FIG. 10 is a sectional view showing an example of the reaction tube.

(Explanation of code)

50 reaction tubes,

5 1 container,

5 2 catalyst,

5 3 Gas inlet,

54 gas outlets,

5 5 Jama board,

5 6 Jama board,

5 7 filter,

101 Mass flow controller (MFC) for controlling the amount of hydrogen introduced, 102, 105 Mass flow controller for controlling the amount of oxygen introduced, 1103, 107 Mixing piping,

1 04 reactor,

1 1 0 Optical dew point meter (moisture concentration meter)

1 1 1 Galpani battery type oxygen meter,

1 1 2 Gas chromatography,

1] 3 concentration system,

1 1 4 Control system,

1 5 sensor,

901 The flow rate of oxygen gas is controlled by a mass flow controller (MFC), and the flow rate of hydrogen gas is controlled by a mass flow controller.

90 3 Argon gas flow rate was controlled by a mass flow controller.

9 0 J Mixing pipe, 9 0 5 reactor,

9 10 Optical dew meter (moisture concentration meter)

9 1 1 Galvanic battery type oxygen meter,

9 1 2 Gas chromatography.

Five

Example of embodiment

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a schematic diagram ^ showing an example of a water generation method including a mixed gas preparation step a1 and a water generation step b1.

10 In Fig. 1, 101 is a mass flow controller (MFC) that controls the amount of introduced hydrogen, 102 is a mass flow controller that controls the amount of introduced oxygen, 103 is a mixing pipe, and 103 is a mixing pipe. 4 is a reactor, 1] 0 is an optical dew point meter (moisture concentration meter), and 111 is a galvanic cell type oxygen meter.

The mixed gas producing step a] is a step performed in 101, 1 () 2 and 103. Appropriate amounts of hydrogen and oxygen are supplied to the mixing pipe 103 through the masochist-controller 101 and 102 to produce a first mixed gas having a predetermined mixing ratio.

The moisture generation step b1 is performed in the reactor 104. The temperature of the reactor 1 () 4 can be controlled by a heating system (not shown), and the first mixed gas introduced into the reactor 1 () 4 can be brought to an appropriate temperature by this heating. .

0 As the reactor 104, for example, gas comes in contact with gas or pipe made of SUS316L, or pipe or vessel made of SUS316L, in which the gas contact part is electropolished or electrolytically polished. A metal having a catalytic action on a part thereof, or a pipe, a finoletor, a container, or the like coated with the metal is suitably used. Examples of the metal having a catalytic action include Hastelloy, nickel, ^ gold, gold, silver and the like, and alloys thereof. The coating may be a single-layer film, which is simple and may be a multi-layer film. Nickel, which is relatively inexpensive and chemically stable, is often used. In order to lower the temperature of the nickel reaction, platinum may be further coated on nickel in some cases.

In addition, as described in Japanese Patent Application No. 6-115590, the gas contacting part of a pipe or vessel made of SUS316L is passivated, and the second mixing is performed. It is also possible to radicalize the hydrogen and oxygen that make up the gas to promote the reaction to generate moisture. The internal shape of the reactor 104 is preferably such that the generated water is smoothly discharged in response to the introduction of the first mixed gas, and the gas retaining portion is reduced in order to obtain an extremely fast response speed.

For example, it is preferable to use a reaction tube shown in FIG. That is, the reaction tube 50 is constituted by an elliptical container 51. SUS316L may be used as a material of the container. In this container, a gas inlet 53 and a gas outlet 54 are formed. A filter 57 having a roughness of about 0.3 / m or more is provided inside the container 51. At least the catalyst (eg, Pt, Pd, Ni, etc.) is formed on the inner surface of the container 51 on the gas outlet 54 side by, for example, a deposition method or a plating method.

At least a jammer plate 56 is provided on the gas outlet 54 side (in the example shown in FIG. 10, a jammer 55 is also provided on the gas inlet 53 side).

The gas introduced into the container 51 from the gas inlet passes through the filter 57 and becomes a laminar flow.

The gas that has passed through the filter flows along the inner wall surface of the container 51 due to the presence of the jammer plate 56. Since the catalyst is formed on the inner wall surface of the container 51, the reaction occurs efficiently.

Although not shown in FIG. 10, a heating means is provided.

FIG. 2 shows a third process in which oxygen is mixed with the second mixed gas generated through the moisture generating process b1 as a post-process of the mixed gas producing process a1 and the moisture generating process b) shown in FIG. FIG. 4 is a schematic diagram showing an example of a moisture generation method including a mixed gas producing step a2 for producing a mixed gas and a moisture generating step b2 for introducing a third mixed gas.

In FIG. 2, 101 is a mass flow controller (MFC) for controlling the amount of introduced hydrogen, 102 and 105 are mass flow controllers for controlling the amount of introduced oxygen, 1 () 3 and 107 are mixing pipes, 104 and 107 are reactors, 110 is an optical dew point meter (water concentration meter), and 111 is a galvanic cell type oxygen meter. 101 to 104 are the same components as in FIG.

Reference numeral 115 denotes a sensor for detecting the concentration of the second mixed gas discharged from the reaction tube 104, and reference numeral 113 denotes a concentration meter. Reference numeral 114 denotes a control system for controlling the MFC based on the signal from the densitometer 113 to control the amount of oxygen mixed.

The mixed gas producing step a2 is a step performed in 105 and 106. The mixing pipe 107 includes the second mixed gas generated in the moisture generation step b] and the second mixed gas. It is used to mix oxygen with a larger amount of hydrogen. The oxygen supplied at this time is controlled by the mass flow controller 105.

When a gas having a ratio of hydrogen to oxygen of 2 or more is used as the first mixed gas, the second mixed gas generated in the water generation step b1 is water in which the main component is generated, and the remainder is not Consisting of hydrogen in the reaction. In order to convert the unreacted hydrogen into moisture, in the mixed gas producing step a2, the second mixed gas and oxygen having a ratio of oxygen to hydrogen contained in the second mixed gas of 0.5 or more are mixed. Then, a third mixed gas is produced.

Next, water is generated by introducing the third mixed gas into the water generation step b2. As a result, the gas finally produced through the moisture generation step b2 can completely convert unreacted hydrogen contained in the second mixed gas into moisture, and is composed of moisture and oxygen. The resulting gas is obtained. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the method for generating moisture of the present invention will be described with reference to the drawings, but the present invention is not limited to these examples.

(Example 1)

In this example, the effect of diluting hydrogen and oxygen with an inert gas was investigated using the conventional moisture generation method shown in FIG. At that time, Ar was used as the inert gas.

The ratio of hydrogen to oxygen was fixed at 2, and the dilution ratio of argon gas was changed.

The impurity concentrations of hydrogen and oxygen (the concentrations of nitrogen, carbon dioxide, organic gas, and metal) were set to 10 ppb or less.

In addition, as a comparative example, a case where the conditions were conventionally performed (dilution ratio: 28, ratio of hydrogen to oxygen: 100) was also examined.

Hereinafter, the description will be made according to the procedure of the moisture generation method.

As shown in Fig. 9, the flow rate of oxygen gas was controlled by the mass flow controller (MFC) 901, the flow rate of water ¾1 gas was controlled by the mass flow controller 902, and the flow rate of argon gas was controlled by the mass flow controller 903. , And passed through a mixing pipe 9 () 4 for mixing three types of gases, and introduced into a reaction furnace 905. Hydrogen and oxygen were reacted in a reaction furnace 905 to generate a mixed gas (first mixed gas) composed of hydrogen and argon containing arbitrary moisture.

A 1-inch diameter, 2-m long Ni tube (Ni-distributed) is used as the reactor 905 However, the catalyst was used to lower the temperature of the reaction. As the Ni tube (Ni pipe), an inner surface subjected to electrolytic polishing was used.

The flow rates of hydrogen gas and oxygen gas were fixed to SO c cZmin and 25 cc Zmin, respectively, using mass flow controllers 90 1 and 902, and only the flow rate of argon gas was used for mass flow controller 903. The gas mixture was changed in the range of 0 2025 c cZmin by using a gas, and a mixed gas composed of three kinds of gases was introduced into the reactor.

The concentration of water contained in the gas mixture consisting of hydrogen and argon flowing out of the reactor was measured using an optical dew meter (moisture concentration meter) 906. The hydrogen, oxygen, and argon gas used were i and the deviation was also an impurity. A high-purity gas having a concentration of 1 Ppb or less was used. The temperature of the reactor 905 was maintained at 300 ° C. over the entire length.

FIG. 3 is a graph showing the result of determining the reaction rate from the measured water concentration. In FIG. 3, the horizontal axis represents the dilution rate of argon gas, and the vertical axis represents the reaction rate. The case where the dilution ratio of the argon gas is 10 is the case where the hydrogen flow rate is 50 cc / min, the oxygen flow rate is 25 ccZmin, and the argon flow rate is 675 cc / min. That is, the dilution ratio of the argon gas is a value obtained by the formula (50 + 25 625) / (50 + 25) = 10. Therefore, when the dilution ratio of the argon gas is 1, the case where only hydrogen and oxygen are introduced without flowing argon is shown. In addition, only when the dilution ratio of the argon gas was 28, the case where the ratio of hydrogen to oxygen was 100 (conventional condition: ▲ in FIG. 3) was examined. The reaction rate means the ratio of (the amount of water actually generated) to (the amount of water that can be generated from the amounts of hydrogen and oxygen introduced). Figure 3 reveals the following points.

(1) When the ratio of hydrogen to oxygen is changed from 100 (conventional value) to 2 at the conventional argon gas dilution ratio of 28, the reaction rate decreases.

(2) When the ratio of hydrogen to oxygen is fixed at 2, lowering the dilution ratio of the argon gas increases the (28-1> reaction).

Therefore, it was found that the reaction rate was highest when water was generated using only hydrogen and oxygen without mixing argon gas as an inert gas. That is, it was found that the water generation method as shown in FIG. 1 was preferable for generating water at a high reaction rate.

(Example 2)

This example differs from Example 1 in that the reaction rate was examined by changing the ratio of hydrogen to oxygen in the first mixed gas using the moisture generation method shown in FIG. The temperature of the reactor 104 Was changed to 300 ° C. \ 400 ° C. and 500 ° C. for the experiment. The other points were the same as in Example 1.

FIG. 4 is a graph showing the result of calculating the reaction rate from the measured water concentration. In FIG. 4, the horizontal axis indicates the ratio of hydrogen to oxygen, and the vertical axis indicates the reaction rate. · The mark is 300 ° (:

540 ° C. The symbol ▲ indicates the result at 500 ° C.

The following points became clear from FIG.

(1) From the result of the temperature of the reactor 104 at 300 ° C (hata mark), it was found that when the ratio of hydrogen to oxygen was 2 or more, a high reaction rate of 50% or more was obtained. Was. In particular, when the ratio of hydrogen to oxygen is 3, the reaction rate can be made approximately 100%.

0 (2) From the results of the temperature of the reactor 104 of 400 ° C (marked) and 500 ° C (▲), when the ratio of hydrogen to oxygen is 2 or more, 10 A reaction rate close to 0% can be stably realized. From these results, by using a scum having a hydrogen to oxygen ratio of 2 or more as the first mixed gas, even when the temperature of the reactor 1 () 4 is considerably low, 50% to 100% It was found that water could be generated with a high t of% and a reaction rate.

5 However, it was found from the measurement using gas chromatography that unreacted hydrogen other than moisture remained in the gas (second mixed gas) obtained after the above reaction.

In order to remove unreacted hydrogen contained in the second mixed gas, oxygen having a ratio of oxygen to hydrogen contained in the second mixed gas of 0.5 or more is mixed, and the third mixed gas is removed. A mixed gas producing step a2 to be produced; introducing the third mixed gas into a reaction tube made of a material having a catalytic action for reacting hydrogen and oxygen; It is sufficient to provide a water generating step b2 for generating water by reacting with oxygen.

Moisture generation process b2 The moisture concentration, oxygen concentration, and hydrogen concentration in the gas flowing out of the reactor that constitutes the reactor are measured using an optical dew meter (moisture concentration meter) 110, a galvanic cell oxygen meter 1 Measurements were made using 11 and gas chromatography 11. As a result, it was found that the force generated through the moisture generation step b2 was a mixed gas composed of moisture and oxygen. In addition, by appropriately adjusting the amount of oxygen mixed with the third mixed scum, it is possible to make the gas that has passed through the water generation step b2 only water. For example, the ratio of hydrogen to oxygen is set to approximately 2, and heating may be performed to 400 ° C. or more. At this time, the amount of oxygen introduced may be controlled by the control system 114.

Therefore, in order to use a gas in which the ratio of hydrogen to oxygen is 2 or more as the first mixed gas and generate water with a high reaction rate of 50 to Water as shown It has been found that a minute generation method is preferred. Industrial applicability

As described above, according to the present invention, a water generation method that has a high reaction rate and can efficiently generate high-concentration water can be obtained.

As a result, the mixed gas preparation step and the water generation step can be reduced. More specifically, the length of the mixing pipe in the mixed gas producing step can be shortened. In addition, the internal volume of the reaction furnace that performs the moisture generation step can be reduced. That is, by using the moisture generation method according to the present invention, a small-sized and high-performance moisture generation mechanism can be obtained.

Further, by diluting the high-concentration water obtained according to the present invention with an arbitrary inert gas, the amount of water contained in the inert gas can be reduced to about 10 ppm from a trace amount of ppm or ppt order. Control over a wide range up to near 0 ° is possible.

Claims

The scope of the claims

1. In the method of generating water by reacting hydrogen and oxygen,

A mixed gas producing step a1 in which hydrogen and oxygen are mixed without dilution with an inert gas to produce a first mixed gas;

A material having a catalytic action for reacting the hydrogen and the oxygen is incorporated therein, or the first mixed gas is introduced into a reaction tube made of the material, and the hydrogen and the oxygen are mixed in the reaction tube. And a water generating step b1 for generating water.

2. A gas in which the ratio of hydrogen to oxygen is 2 (molar ratio) or more is used as the first mixed gas, and the second mixed gas generated in the moisture generation step b1 is added to the second mixed gas. A mixed gas producing step a2 of producing a third mixed gas by mixing oxygen such that the ratio of oxygen to hydrogen contained in hydrogen becomes 0.5 or more;

The third mixed gas is introduced into a second reaction tube made of a material having a catalytic action for reacting hydrogen and oxygen, or is introduced into the second reaction tube made of the material. A water generation step b2 for reacting hydrogen with oxygen to generate water,

2. The method for producing moisture according to claim 1, wherein the method comprises:

3. The method according to claim 1, wherein the impurity concentrations of the hydrogen and the oxygen are 10 ppb or less.

4. The method according to claim 3, wherein the impurity concentration of the hydrogen and the oxygen is 1ϋppt or less.

5. The method according to claim 3, wherein the impurities are at least one of nitrogen, carbon dioxide, and organic gas.

6. The method according to claim 1, wherein the water is water to be introduced into an apparatus for forming a semiconductor oxide film.

7. The hydrogen source,

Means for controlling the hydrogen flow rate;

An oxygen source,

Means for controlling the oxygen flow rate;

A first mixing section for mixing the hydrogen and the oxygen to produce a first mixed gas; A reaction tube containing a material having a catalytic action for reacting the hydrogen and the oxygen constituting the first mixed gas or comprising the material;

A moisture generator comprising:

8. A second mixing section downstream of the reaction tube for mixing oxygen with the second mixed gas from the reaction tube to produce a third mixed gas;

The water generator according to claim 7, further comprising: means for introducing the third mixed gas from the second mixing section to the second reaction tube.

9. Detecting means for detecting the component concentration of the second mixed gas,

9. The water generator according to claim 8, further comprising a control system for controlling an amount of oxygen mixed with the second mixed gas based on a signal from the detection means.