Moisture generation reactor

Abstract

[Problem] To provide a reaction furnace for moisture generation capable of achieving a higher moisture generation ratio while preventing the risk of ignition. [Solution] The present invention comprises: a reaction furnace main body 6 which has an inlet 2 and an outlet 4 for a gas; a first reflecting plate 7 which is disposed to face the outlet 4, and fixed to the inside of the reaction furnace main body 6 while maintaining a gap G2 with an inner wall surface of the reaction furnace main body 6, and which has a tapered portion 10 at a peripheral edge portion facing the inner wall surface of the reaction furnace main body 6; a first platinum catalyst layer 9 which is coated on the inner wall surface of the reaction furnace main body 6; and a second platinum catalyst layer 11 which is coated on an outer surface of the first reflecting plate 7, which is a side opposing the reaction furnace main body 6 and disposed more inward than the tapered portion 10.

Description

[Technical Field]

[0001] The present invention relates to a moisture generating reactor that is used mainly in semiconductor manufacturing equipment and that generates moisture by reacting hydrogen gas with oxygen gas. [Background technology]

[0002] A conventional moisture-generating reactor 1C, as shown in Fig. 6, is known as a conventional reactor of this type. This moisture-generating reactor 1C includes a reactor body 6 formed by welding an inlet-side reactor body member 3 having a raw material gas inlet 2 and an outlet-side reactor body member 5 having a moisture gas outlet 4 in an opposing relationship, a first reflector 7 disposed inside the reactor body 6 opposite the outlet 4 and fixed to the inner wall surface of the reactor body 6 with a gap G2 therebetween, and a second reflector 8 disposed inside the reactor body 6 opposite the raw material gas inlet 2 and fixed to the inner wall surface of the reactor body 6 with a gap G1 therebetween. A platinum catalyst layer 9 is coated on the inner wall surface of the outlet-side reactor body member 5. For ease of understanding, the platinum catalyst layer is illustrated exaggerated by dashed lines.

[0003] The moisture generating reactor 1C configured as described above supplies oxygen gas and hydrogen gas into the reactor body 6 through the raw material gas inlet 2, and by causing a catalytic reaction with the platinum catalyst layer 9 at a catalytic reaction temperature (400°C or less) lower than the ignition point of hydrogen gas and oxygen gas (500 to 580°C), high-purity moisture gas can be generated without combustion and extracted from the moisture gas extraction port.

[0004] 6, a tapered portion 10 is provided on the peripheral edge of the first reflector 7 facing the inner wall surface of the reactor body 6, thereby enabling stable generation of moisture without causing unexpected ignition or combustion. That is, since the catalytic reaction is strong at the portion that enters the gap G2 between the first reflector 7 and the reactor body 6, the provision of the tapered portion 10 prevents the raw material gas from suddenly flowing into the gap G2, suppressing the occurrence of a strong catalytic reaction and preventing a localized sudden rise in temperature and ignition. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-169109 Summary of the Invention [Problem to be solved by the invention]

[0006] The conventional water generation reactor described above can achieve a water generation rate of 98% while preventing the risk of fire, and a stable high water generation rate has been achieved. However, there is a demand for a higher water generation rate while preventing the risk of fire.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a reactor for generating moisture that can achieve a higher moisture generation rate while preventing the risk of fire. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, a moisture generating reactor according to one embodiment of the present invention comprises a reactor body having a gas inlet and outlet, a first reflector disposed opposite the outlet, fixed within the reactor body with a gap maintained between the first reflector and the inner wall surface of the reactor body, and having a tapered portion on its peripheral edge facing the inner wall surface of the reactor body, a first platinum catalyst layer coated on the inner wall surface of the reactor body, and a second platinum catalyst layer coated on the outer surface of the first reflector on the side facing the reactor body and inside the tapered portion.

[0009] The reactor may further include a ring-shaped spacer interposed between the first reflector and the inner wall surface of the reactor body to maintain the gap, and a fixing screw for fixing the first reflector to the reactor body through the ring-shaped spacer, and the second platinum catalyst layer may be coated on the outer surface except for the portion where the ring-shaped spacer abuts the first reflector.

[0010] The second platinum catalyst layer may be coated on the inner side of the ring-shaped spacer.

[0011] The entire inner wall surface of the reactor body and the entire first reflector may be coated with a barrier film, and the first platinum catalyst layer and the second platinum catalyst layer may be coated on the barrier film.

[0012] The reactor may further include a second reflector disposed opposite the inlet, fixed inside the reactor body with a gap between it and the inner wall surface of the reactor body, and having a tapered portion on its peripheral edge facing the inner wall surface of the reactor body, and the second reflector may be configured such that the entire surface of the second reflector is coated with a barrier film and is not coated with a platinum catalyst layer. [Effects of the Invention]

[0013] According to the present invention, by coating the outer surface of the first reflector on the side facing the reactor body and inside the tapered portion with a second platinum catalyst layer, it is possible to achieve a higher moisture generation rate while preventing the risk of fire. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view showing a first embodiment of a reactor for generating moisture according to the present invention. [Figure 2] FIG. 2 is a partially enlarged view of FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view showing a modification of the embodiment shown in FIG. 3. [Figure 5] FIG. 2 is a cross-sectional view showing a second embodiment of a reactor for generating moisture according to the present invention. [Figure 6] FIG. 1 is a cross-sectional view showing a conventional reactor for generating moisture. DETAILED DESCRIPTION OF THE INVENTION

[0015] An embodiment of a reactor for generating moisture according to the present invention will be described below with reference to Figures 1 to 5. Note that the same or similar components are designated by the same reference numerals throughout all figures and all embodiments, including those of the prior art.

[0016] Referring to FIG. 1, the moisture generating reactor 1A according to the first embodiment comprises a reactor body 6 having an inlet 2 for raw material gas (oxygen and hydrogen) and an outlet 4 for moisture gas and unreacted raw material gas, a first reflector 7 arranged opposite the outlet 4, fixed within the reactor body 6 while maintaining a gap G2 with the inner wall surface of the reactor body 6, and having a tapered portion 10 on its peripheral edge facing the inner wall surface of the reactor body 6, a first platinum catalyst layer 9 coated on the inner wall surface of the reactor body 6, and a second platinum catalyst layer 11 coated on the outer surface of the first reflector 7 on the side facing the reactor body 6, inside the tapered portion 10.

[0017] Furthermore, the moisture generating reactor 1A is equipped with a second reflector 8. The second reflector 8 is disposed opposite the inlet 2 and is fixed inside the reactor main body 6 while maintaining a gap G1 with the inner wall surface of the reactor main body 6, and has a tapered portion 12 on its periphery facing the inner wall surface of the reactor main body 6. The second reflector 8 has the function of efficiently diffusing the raw material gas flowing in from the inlet 2 into the reactor main body 6.

[0018] The reactor body 6 has a short cylindrical outer shape and is formed by joining an inlet-side reactor body member 3 and an outlet-side reactor body member 5. An internal space P is formed by a recess 3a in the inlet-side reactor body member 3 and a recess 5a in the outlet-side reactor body member 5. The recesses 3a and 5a are joined by butting and welding their respective peripheral flanges 3b and 5b together. A gas inlet 2 is provided in the inlet-side reactor body member 3. A moisture gas outlet 4 is provided in the outlet-side reactor body member 5.

[0019] The first platinum catalyst layer 9 is mainly coated on the outlet-side reactor body member 5. The inlet-side reactor body member 3 may also have the first platinum catalyst layer 9 coated on the inner surface of the peripheral flange portion 3b.

[0020] If the second reflector 8 is coated with a platinum catalyst layer, a catalytic reaction will occur in the gap G1 as soon as the gas enters the furnace. The second reflector 8 has a smaller heat capacity than the furnace body and is therefore prone to high temperatures, and cannot dissipate heat to the outside like the reactor body 6. Therefore, coating the second reflector 8 with a platinum catalyst layer may result in fire. Therefore, it is preferable not to coat the second reflector 8 with a platinum catalyst layer.

[0021] The second reflector 8 and the first reflector 7 both have a disk shape. The second reflector 8 and the first reflector 7 are attached to the inner wall surface of the reactor main body 6 via gaps G1 and G2, respectively, in a substantially parallel relationship, and the tapered portions 10 and 12 are formed so that the distance from the inner wall surface of the reactor main body 6 increases as they approach the outer periphery.

[0022] The reactor body 6, the first reflector 7, and the second reflector 8 can be made of stainless steel, but can also be made of other materials, such as nickel alloy, aluminum alloy, iron-chromium-aluminum alloy, etc.

[0023] The inner surface of the reactor body 6, the surface of the first reflector 7, and the surface of the second reflector 8 are entirely coated with a barrier coating 13 that is inactive to oxygen and hydrogen. The first platinum catalyst layer 9 and the second platinum catalyst layer 11 are coated on top of the barrier coating 13. The barrier coating prevents impurities in the base material, such as stainless steel, that constitutes the reactor body 6 from being released to the outside and from diffusing into the platinum catalyst layer, thereby preventing deterioration of the platinum catalyst layer.

[0024] Known materials can be used for the barrier coating 13. Examples of known barrier coating materials include TiN, Al2O3, TiCN, TiAlN, Cr2O3, SiO2, CrN, Y2O3, and mixtures of Y2O3 with other metal oxides (Ta2O5, SiO2, TiO2, ZrO2, Al2O3, HfO2, La2O3, CeO2, Ce2O3, MgO, and ThO2). The barrier coating 13 can be formed by ion plating, ion sputtering, PVD such as vacuum deposition, chemical vapor deposition (CVD), hot pressing, or thermal spraying. The thickness of the barrier coating 13 can be approximately 0.1 μm to 5 μm.

[0025] The first platinum catalyst layer 9 and the second platinum catalyst layer 11 can be formed by vacuum deposition, ion plating, sputtering, chemical vapor deposition, hot pressing, or the like. The thickness of the first platinum catalyst layer 9 and the second platinum catalyst layer 11 is preferably 0.1 μm to 3 μm. For ease of understanding, the platinum catalyst layers are exaggerated and shown by dashed lines in FIG. 1.

[0026] The first reflector 7 is fixed to the reactor body 6 by a fixing screw 15 via a ring-shaped spacer 14. A gap G2 is maintained between the first reflector 7 and the inner wall surface of the reactor body 6 by the ring-shaped spacer 14 through which the fixing screw 15 passes. The second reflector 8 is similarly fixed to the reactor body 6 by a fixing screw 17 via a ring-shaped spacer 16. The gaps G1 and G2 are preferably set to 0.5 to 1.0 mm, and are set to 0.5 mm in the illustrated example. The barrier coating is also provided on the surfaces of the ring-shaped spacers 14 and 16 and the fixing screws 15 and 17.

[0027] The fixing screws 15 are disposed radially inward of the tapered portion 10 of the first reflecting plate 7 along the tapered portion 10 at predetermined angular intervals (for example, four locations at 90° intervals).

[0028] In the moisture generation reactor 1A having the above configuration, the catalytic reaction is increased by coating the first reflector 7 with the second platinum catalyst layer 11, and a higher moisture generation rate can be obtained.

[0029] As described above, tapered portion 10 prevents a sudden inflow of source gas into gap G2, thereby preventing a rapid rise in temperature, but if second platinum catalyst layer 11 is also coated on tapered portion 10, the catalytic reaction will become stronger in combination with the reaction with first platinum catalyst layer 9, causing a sudden rise in temperature and the risk of fire. For this reason, second platinum catalyst layer 11 is coated on the surfaces inside tapered portion 10, excluding tapered portion 10.

[0030] Furthermore, in the illustrated example, depending on the material of the ring-shaped spacer 14 and variations in the tightening torque of the fixing screws 15, the second platinum catalyst layer 11 may be damaged where the ring-shaped spacer 14 comes into contact with the second platinum catalyst layer 11 when the fixing screws 15 are tightened, which may result in a fire. Therefore, it is preferable that the second platinum catalyst layer 11 is not coated on the portion that comes into contact with the ring-shaped spacer 14, and it is preferable that the second platinum catalyst layer 11 is coated in a circular shape radially inward from the ring-shaped spacer 14. Furthermore, to reliably avoid contact with the ring-shaped spacer 14, it is preferable that the second platinum catalyst layer 11 be spaced a predetermined distance L (FIGS. 2 and 3) from the ring-shaped spacer 14. The distance L may be 4 to 7 mm.

[0031] 4, the surface inside the tapered portion 10 can be coated with a second platinum catalyst layer 11, excluding only the contact area with the ring-shaped spacer 14. The first platinum catalyst layer 9 can also be coated, excluding only the contact area with the ring-shaped spacer 14.

[0032] On the other hand, the amount of unreacted gas in the gas that flows into gap G2 decreases as it approaches outlet 4, and the amount of unreacted gas that reaches the middle of gap G2 is small, so even if platinum catalyst layers are present on both first reflector 7 and reactor body 6, a reaction (temperature rise) large enough to cause ignition does not occur. This makes it possible to achieve a higher moisture generation rate while preventing the risk of ignition.

[0033] 5 shows a second embodiment of the moisture-generating reactor according to the present invention. The moisture-generating reactor 1B of the second embodiment is provided with a slightly thicker first reflector 7, but does not have the second reflector 8 of the first embodiment, making it more compact. The other configurations of the second embodiment are the same as those of the first embodiment, so detailed description will be omitted.

[0034] The present invention should not be construed as being limited to the above-described embodiment, and various modifications are possible within the scope of the invention. [Explanation of symbols]

[0035] 1A, 1B, 1C Moisture generating reactor 2 entrance 3. Furnace body components on the inlet side 4 exit 5 Outlet side furnace body component 6. Reactor body 7 1st reflector 8 Second reflector 9 First platinum catalyst layer 10 Tapered section 11 Second platinum catalyst layer 14,16 Ring-shaped spacer 15,17 Fixing screws

Claims

1. a reactor body having a gas inlet and an outlet; a first reflector disposed opposite the outlet, fixed in the reactor body with a gap maintained between the first reflector and the inner wall surface of the reactor body, and having a tapered portion formed on a peripheral edge portion facing the inner wall surface of the reactor body such that the distance between the first reflector and the inner wall surface of the reactor body increases toward the outer periphery; a first platinum catalyst layer coated on the inner wall surface of the reactor body; a second platinum catalyst layer coated on an outer surface of the first reflector facing the reactor body and inside the tapered portion; A reactor for generating moisture, comprising:

2. a ring-shaped spacer interposed between the first reflector and the inner wall surface of the reactor body to maintain the gap; a fixing screw for fixing the first reflector to the reactor body through the ring-shaped spacer; Further provided with 2. The reactor for generating moisture according to claim 1, wherein the second platinum catalyst layer is coated on the outer surface of the ring-shaped spacer except for a portion where the ring-shaped spacer abuts against the first reflector.

3. 3. The reactor for generating moisture according to claim 2, wherein the second platinum catalyst layer is coated on an inner side of the ring-shaped spacer.

4. 2. The reactor for generating moisture according to claim 1, wherein the entire inner wall surface of the reactor body and the entire first reflector are coated with a barrier film, and the first platinum catalyst layer and the second platinum catalyst layer are then coated on top of the barrier film.

5. a second reflector disposed opposite the inlet, fixed in the reactor body with a gap maintained between the second reflector and the inner wall surface of the reactor body, and having a tapered portion formed on a peripheral portion facing the inner wall surface of the reactor body such that the distance between the second reflector and the inner wall surface of the reactor body increases toward the outer periphery; The reactor for generating moisture according to claim 1 , wherein the second reflector is entirely coated with a barrier film and is not coated with a platinum catalyst layer.

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