JPH11137946A - Dehumidifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress enrichment of oxygen in a space to be dehumidified in a dehumidifier using an electrochemical element, by forming a shielding room in the anode side of the electrochemical element by using a membrane so as to separate the anode from the space to be dehumidified body in the dehumidifier and further forming small holes in the peripheral part of the shielding room. SOLUTION: The anode 1 and the cathode 2 of the electrochemical element E consist of a porous material, and a Nafion (R) film is used for the solid polymer electrolyte film 3. The solid polymer electrolyte film 3 is held between the anode 1 and the cathode 2 and joined by hot press. Feeder bodies 4 are attached to the peripheral part of the electrode faces 1a, 2a of the anode 1 and the cathode 2 to form the electrochemical element E. The electrochemical element E is disposed with the anode 1 facing to the space 7 to be dehumidified, and a shielding room 9 is formed by a membrane 10 which transmits water vapor but does not transmit oxygen so as to separate the electrode face 1a of the anode 1 from the space 7 to be dehumidified. Thereby, increase in the oxygen gas concn. in the space 7 to be dehumidified can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a dehumidifier using an electrochemical device.

[0002]

2. Description of the Related Art As shown in FIG. 4, for example, a dehumidifier of this type comprises an anode 1 for electrolyzing water to generate oxygen, and a cathode 2 for reacting hydrogen ions with oxygen to generate water or water vapor. It is common to use an electrochemical element E having a laminated structure in which a solid polymer electrolyte membrane 3 serving as a hydrogen ion exchange membrane is sandwiched between the anode 1 and the cathode 1. In the state of being sandwiched between a pair of power supply bodies 4 and 4 stacked and mounted on the respective electrode surfaces 1a and 2a, the periphery thereof is tightened by an insulating resin frame 5, and
The periphery of the resin frame 5 is fixed with an adhesive and gas-sealed. The anode 1 and the cathode 2 are connected to an external power supply 6 for applying a predetermined DC voltage via feeders 4 and 4 mounted on and stacked on the respective electrode surfaces 1a and 2a. .

The anode 1 and the cathode 2 are both formed of a porous base material, and a part of each of the anode 1 and the cathode 2 is cut into the surface of the solid polymer electrolyte membrane 3.
When a DC voltage is applied between the electrodes 1 and 2 from the external power supply 6, a reaction of the following formula (1) for electrolyzing water occurs at the anode 1, and the atmosphere in the dehumidified space 7 formed on the anode 1 side is formed. Is dehumidified and oxygen is enriched at the same time. _{2H 2 O → O 2 + 4H} + + 4e - ····· (1)

Then, hydrogen ions (H ⁺ ) generated at this time move from the anode 1 side to the cathode 2 side through the solid polymer electrolyte membrane 3, and electrons (e ⁻ ) are passed through the circuit of the external power supply 6. 2 at the cathode 2, a reaction of the following formula (2) occurs in which hydrogen ions and oxygen react with each other to generate water or steam, and the atmosphere in the humidified space 8 formed on the cathode 2 side is humidified. At the same time, oxygen is removed. O ₂ + 4H ⁺ + 4e ⁻ → 2H ₂ O (2)

[0005]

However, in the above dehumidifying apparatus, if the humidity difference between the space 7 to be dehumidified and the space 8 to be humidified is too large, the air in the space 8 The water vapor contained permeates through the solid polymer electrolyte membrane 3 from the cathode 2 side and penetrates into the anode 1 side, so that the reaction of the above formula (1) for electrolyzing water occurs continuously at the anode 1, As a result, oxygen in the dehumidified space 7 continues to increase abnormally.

For this reason, when the space 7 to be dehumidified is in the storage of a storage for storing foods and other storage items, the storage is filled with oxygen gas at a high concentration, and the active gas generated from the anode 1 is activated. Oxidation of foods and the like is promoted by oxygen and ozone generated as a by-product, and when the inside of the refrigerator has an airtight structure,
The accumulation of oxygen gas may cause an increase in the internal pressure of the storage, which may cause damage to a part of the storage, and increase the flammability or the ignitability of the storage with the increase of the oxygen-supporting gas. There is danger.

Therefore, an object of the present invention is to suppress oxygen enrichment in a space to be dehumidified without impairing the dehumidifying performance of the dehumidifying device.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to an anode for electrolyzing water to generate oxygen, and a cathode for reacting hydrogen ions with oxygen to generate water or water vapor. In a dehumidifier using a laminated electrochemical element in which a solid polymer electrolyte membrane serving as a hydrogen ion exchange membrane is sandwiched, a water vapor is provided on the anode side of the electrochemical element disposed toward the dehumidified space. Is formed by a film body that transmits but does not transmit oxygen, and a shielding chamber that separates the anode from the space to be dehumidified is formed, and oxygen generated from the anode is released to the outside around the shielding chamber. It is characterized in that micropores are formed.

According to the present invention, oxygen generated by electrolyzing water at the anode of the electrochemical element is placed in a shielded room in which the oxygen-permeable membrane separates the electrode surface of the anode from the space to be dehumidified. It is sealed and released to the outside through the fine holes formed in the periphery of the shielding room, so that oxygen enrichment in the space to be dehumidified is suppressed. In addition, since the membrane that separates the electrode surface of the anode from the space to be dehumidified does not transmit oxygen but does transmit water vapor, the water vapor in the space to be dehumidified moves to the shielding room and is electrolyzed by the anode. The atmosphere in the space to be dehumidified is dehumidified.

[0010]

Embodiments of the present invention will be specifically described below with reference to the drawings. 1 to 3 are cross-sectional views each showing an example of a dehumidifier according to the present invention. The parts corresponding to those of the conventional apparatus shown in FIG.

In the dehumidifier of the present invention shown in FIGS. 1 and 2, the anode 1 and the cathode 2 of the electrochemical element E
It is composed of a titanium substrate having a thickness of 0.06 mm and an effective film area of 100 × 100 mm, and a 1 μm-thick platinum-plated porous substrate.

As the solid polymer electrolyte membrane 3 sandwiched between the anode 1 and the cathode 2, a 170 μm-thick Nafion membrane (Nafion: trade name of DuPont) is used, and a Nafion solution (5 wt. % Aqueous alcohol solution) mixed with platinum black and dried, and 0.5mg / unit area
/ Cm ² of platinum black is carried on the anode and cathode surfaces.

[0013] A solid polymer electrolyte membrane 3 is sandwiched between the anode 1 and the cathode 2, and they are heated at a temperature of 170 ° C and 50 kg / cm.
After hot-pressing and joining at a pressure of ² , feeders 4, 4 connected to an external power supply 6 are mounted around the electrode surfaces 1 a, 2 a of the anode 1 and the cathode 2, respectively. , And the periphery of the resin frame 5 is gas-sealed and fixed, whereby the electrochemical element E is formed.

Next, the electrochemical element E is disposed so that the anode 1 faces the space 7 to be dehumidified, and a film 10 that transmits water vapor but hardly transmits oxygen is provided on the anode 1 side.
Thereby, a shielding chamber 9 for isolating between the electrode surface 1a of the anode 1 and the space 7 to be dehumidified is formed.

The shielding chamber 9 shown in FIG. 1 is formed by bonding a resin frame 11 joined by sealing the periphery of the film body 10 by gas sealing along the periphery of the insulating resin frame 5 which is the periphery of the electrochemical element E. In addition, a fine hole 12 for releasing oxygen generated from the anode 1 of the electrochemical element E to the outside is formed in a part of the resin frame 11.

As the film body 10, a Nafion film having a thickness of 0.05 mm is used, and the Nafion film is disposed so as to face the electrode surface 1 a of the anode 1 of the electrochemical element E in parallel at a constant interval. I have. The fine hole 12 is formed as a through hole having a diameter of about 1 mm and formed in the resin frame 11 which forms a peripheral portion of the shielding chamber 9. The distance between the electrode surface 1a of the anode 1 of the electrochemical element E and the film body 10 is usually selected to be about 2 to 10 mm, but is appropriately changed according to the effective film area of the film body 10.

The shielding chamber 9 shown in FIG. 2 is formed by a porous film body 14 having a large number of fine holes 13 through which a gas such as oxygen or ozone is transmitted. Unlike the chamber 9, as the porous film body 14, for example, a water-repellent Teflon film (PTFE film) having the micropores 13 having a pore diameter of 0.6 μm is used. Further, instead of the resin frame having the through-holes forming the peripheral portion of the shielding chamber 9 shown in FIG. 1, a metal frame having a narrow gap of, for example, 0.2 to 0.6 mm can be used.

The above is the configuration of the device of the present invention shown in FIG. 1 and FIG. 2. Next, the operation and effect will be described.
When the same device E as the electrochemical device E according to the device of the present invention shown in FIGS. 1 and 2 was applied to the conventional device shown in FIG. 4, a dehumidification experiment was performed in which a DC voltage of 3 V was applied to the device E.
According to the conventional device, the surrounding environment is room temperature 20 ° C and humidity 90%.
Under the conditions described above, the amount of increase in oxygen gas in the space 7 to be dehumidified is
It was 0.4 liter / hr. In contrast, FIGS. 1 and 2
According to the device of the present invention, oxygen generated from the anode 1 of the electrochemical element E is supplied from the inside of the shielding chamber 9 to the fine holes 12 or 13.
Is released to the outside, and is prevented from entering the dehumidification space 7 by the film body 10 that does not transmit oxygen. Therefore, the increase of oxygen gas in the dehumidification space 7 is suppressed to substantially zero.

On the other hand, with respect to the dehumidifying performance, in the apparatus of the present invention shown in FIGS. 1 and 2, the water vapor in the dehumidified space 7 is shielded from the dehumidified space 7 by the film body 10 that allows the water vapor to pass therethrough. Due to the humidity gradient generated between the inside of the room 9 and the inside of the room 7 to be continuously transferred from the space 7 to be dehumidified to the inside of the shielded room 9, substantially the same as the conventional apparatus of FIG.
A dehumidifying performance of 7.0 cc / hr (a dehumidifying ability to reduce the relative humidity from 90% to 10%) is obtained, and even if the film surface 10 separates the space 1 between the electrode surface 1a of the anode 1 and the space 7 to be dehumidified. Chemical element E
It was confirmed that the dehumidifying performance of was not impaired.

Further, as in the apparatus of the present invention shown in FIGS. 1 and 2, between the anode 1 of the electrochemical element E and the space 7 to be dehumidified, a shield is brought into a positive pressure state by the oxygen gas generated from the anode 1. When the space of the chamber 9 is formed, the action of the water vapor in the humidified space 8 from the fine holes 12 or 13 arranged in a part of the shielding chamber 9 is also caused by the action due to the pressure difference of the positive pressure space. Since it is suppressed, the dehumidifying performance of the electrochemical element E is not impaired.

The porous substrate constituting the anode 1 and the cathode 2 of the electrochemical element E is not limited to the above-mentioned titanium mesh sheet, but is formed by forming nickel, tantalum, stainless steel, carbon or the like into a fiber sheet. Alternatively, a sheet formed while maintaining the porosity can be used.

The porous membrane 14 shown in FIG. 2 is formed of an organic polymer material such as Teflon, polypropylene or polyester, or a ceramic material such as glass fiber, alumina fiber, silica fiber or mullite fiber. Are used.

Although not shown, FIGS. 1 and 2
Since the solid polymer electrolyte membrane constituting the membrane body 10 is rich in hygroscopicity, it swells and is significantly deformed in a high humidity environment. When the reinforcing porous membrane having a large number of micropores to be attached is attached, the mechanical strength of the membrane 10 is reinforced, and the membrane 10 is not likely to be damaged. As a reinforcing porous membrane having a high mechanical reinforcing effect, a Teflon porous membrane that has no hygroscopicity and hardly deforms even when the solid polymer electrolyte membrane swells is suitable.

Next, the dehumidifier of the present invention shown in FIG.
1 and 2 in that the space between the space 7 to be dehumidified and the anode 1 of the electrochemical element E disposed toward the space is separated by a film body 10 that transmits water vapor but does not transmit oxygen. Although it is common to the dehumidifier, a porous film body having a large number of micropores 15 permeable to water vapor and oxygen without forming a shielding chamber 9 and a space between the film body 10 and the anode 1 ( 16) is different from the dehumidifier of FIG. 1 and FIG.

In the apparatus shown in FIG. 3, the porous membrane 16 sandwiched between the membrane 10 and the anode 1 of the electrochemical element E comprises:
At the same time as functioning as a reinforcing material for preventing damage to the membrane 10, the pores of the micropores 15 of the porous membrane 16 are
As in the case of the shielded chamber 9 shown in FIGS. 1 and 2, the water vapor in the humidified space 8 has an effect of suppressing the permeation of the water vapor from the cathode 2 side through the solid polymer electrolyte membrane 3 and into the anode 1 side. And further, the fine holes 15 on the peripheral edge side of the porous film body 16.
However, as in the case of the micropores 12 of FIG. 1 and the micropores 13 of FIG. 2, it has an effect of releasing oxygen generated from the anode 1 to the outside.

The porous membrane 16 is formed of an organic polymer material such as Teflon, polypropylene or polyester, or a ceramic material such as glass fiber, alumina fiber, silica fiber or mullite fiber,
Is selected to be about 10 μm.

[0027]

According to the dehumidifying device of the present invention, oxygen generated from the anode of the electrochemical element does not accumulate and fill the space to be dehumidified when the atmosphere in the space to be dehumidified is dehumidified.
As with the conventional device, the danger that the oxygen gas concentration in the space to be dehumidified is increased and the ignitability and flammability of various storage items stored in the space is increased is eliminated, and at the same time, the active gas generated from the anode is removed. There is a very excellent effect that the danger of oxidizing or deteriorating the stored material due to oxygen or ozone generated by the side is eliminated.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a dehumidifier according to the present invention.

FIG. 2 is a sectional view showing an example of a dehumidifying device according to the present invention.

FIG. 3 is a sectional view showing an example of a dehumidifier according to the present invention.

FIG. 4 is a sectional view showing a conventional dehumidifier.

[Explanation of symbols]

 E ... Electrochemical element 1 ... Anode 2 ... Cathode 3 ... Solid polymer electrolyte membrane 7 ... Dehumidified space 9 ... Shield Chamber 10 ··· Membrane 12 ··· Micropores 13 ··· Micropores 14 ··· Porous membrane 15 ··· Micropores 16 ··· Porous Membrane

Continued on the front page (72) Inventor Mitsuhiro Nakamura 193-1 Hamakawa Nitta, Oto-cho, Ogasa-gun, Shizuoka Prefecture Inside Optec Didi Melco Laboratory (72) Inventor Hideyuki Tsukamoto Ogasa-gun, Shizuoka Prefecture 193-1 Higashicho Hamakawa Nitta Inside Optec Didi Melco Laboratory Co., Ltd. (72) Inventor Miyuki Imaizumi 193-13-1 Hamakawa Nitta Ohitomachi Ogasa-gun Shizuoka Prefecture Inside Optec Didi Melco Laboratories (72) Inventor Teruaki Ikutame 193-1-1, Hamakawa Nitta, Daito-cho, Ogasa-gun, Shizuoka Prefecture Inside the Optec Didi Melco Laboratory (72) Inventor Seiichi Sato 1933, Hamakawa Nitta, Oto-cho, Ogasa-gun, Shizuoka Prefecture -1 Inside Optec Didi Melco Laboratory, Inc. (72) Inventor Takeshi Yokomatsu 193-1-1, Hamakawa Shinda, Oto-gun, Ogasa-gun, Shizuoka Prefecture Inside Optitech Didi Melco Laboratories, Inc. (72) Inventor Eternity Hideo Ii 193-1 Hamakawa Nitta, Daito-cho, Ogasa-gun, Shizuoka Prefecture Inside the Optec Didi Melco Laboratory (72) Inventor Kenro Mitsuda 2-3-2 Marunouchi 2-chome, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. In-company (72) Inventor Shiro Yamauchi 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation

Claims (10)

[Claims] A solid polymer electrolyte membrane serving as a hydrogen ion exchange membrane is provided between an anode for generating oxygen by electrolyzing water and a cathode for reacting hydrogen ions with oxygen to generate water or water vapor. In the dehumidifier using the sandwiched electrochemical element having a laminated structure, water vapor permeates oxygen but permeates the anode (1) side of the electrochemical element (E) disposed toward the space to be dehumidified (7). A shield chamber (9) is formed between the anode (1) and the space to be dehumidified (7) by the membrane (10) not to be formed, and the anode ( A dehumidifier characterized in that micropores (12, 13) for releasing oxygen generated from 1) to the outside are formed. 2. The dehumidifier according to claim 1, wherein the membrane is a solid polymer electrolyte membrane. 3. A reinforcing porous membrane having a large number of fine pores for allowing water vapor to pass therethrough is provided on one side, both sides or inside of the membrane (10) comprising a solid polymer electrolyte membrane. 2. The dehumidifier according to 2. 4. The dehumidifier according to claim 3, wherein the reinforcing porous membrane is a Teflon sheet having a large number of fine holes. 5. The shielding chamber (9), wherein the micro holes (12) are provided.
2. The dehumidifier according to claim 1, wherein the through hole is formed in a resin frame (11) forming a peripheral portion of the dehumidifier. 6. The dehumidifier according to claim 1, wherein the fine hole is a narrow gap of a metal frame forming a peripheral portion of the shielding chamber (9). 7. The shielding chamber (9), wherein the micro holes (13) are provided.
2. The dehumidifier according to claim 1, wherein the porous membrane (14) constituting the peripheral portion has fine pores. 8. The porous membrane (14) is formed of an organic polymer material such as Teflon, polypropylene or polyester, or a ceramic material such as glass fiber, alumina fiber, silica fiber or mullite fiber. 5. The dehumidifying device according to 5. 9. A solid polymer electrolyte membrane serving as a hydrogen ion exchange membrane is provided between an anode which electrolyzes water to generate oxygen and a cathode which reacts hydrogen ions with oxygen to generate water or water vapor. In the dehumidifier using the sandwiched electrochemical element having a laminated structure, water vapor permeates between the space (7) to be dehumidified and the anode (1) of the electrochemical element (E) arranged toward the space. Membrane that does not transmit oxygen (1
0) and a porous membrane (16) between the membrane (10) and the anode (1) having a number of micropores (15) permeable to gases such as oxygen and ozone. ) Is sandwiched between them. 10. The porous membrane (16) is formed of an organic polymer material such as Teflon, polypropylene or polyester, or a ceramic material such as glass fiber, alumina fiber, silica fiber or mullite fiber. 7. The dehumidifier according to 7.