JP2006255158A - Oxygen pump element and oxygen supplying device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oxygen pump element which is a low-current/high-voltage type and has a high heating efficiency, and has a narrow temperature distribution and good characteristics. <P>SOLUTION: Pairs of electrode parts 16, 17, 20, and 21 making a plurality of capacitors are formed on a solid electrolyte board 15, which is oxygen ion conductive; the electrode parts are configured to be a series circuit electrically; an insulation film 18 is made in a region, on one side or both sides of the solid electrolyte board 15, where no electrode part is formed; and after that, a heater resistor 19 is arranged on the insulation film 18. This realizes a heater with high heating efficiency and the narrow temperature distribution of the solid electrolyte board 15, and achieves the oxygen pump element capable of saving electric power well. In addition, because a plurality of electrode parts are configured in the series circuit, the low-current/high-voltage type can be made, and a drive control circuit is configured at low cost. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an oxygen pump element that moves oxygen contained in air using an oxygen ion conductive solid electrolyte substrate, and an oxygen supply device using the oxygen pump element.

  Conventionally, this type of oxygen pump is operated as an oxygen pump by providing electrode films on both surfaces of an oxygen ion conductive solid electrolyte substrate, applying a power supply voltage (see, for example, Patent Document 1).

  As shown in FIG. 6, electrode films 3 and 4 are formed on the upper and lower surfaces of a solid electrolyte substrate 2 made of zirconia or the like, and the electrode films 3 and 4 are connected to a DC power source 5 via lead wires. It is connected to the. In such a configuration, the solid electrolyte substrate 2 was heated by an external heater (not shown) or the like and maintained at a high temperature of about 500 to 600 ° C., and the oxygen pump 1 was formed. That is, when oxygen-containing air or the like collides with the electrode film 4 on the lower surface, the contained oxygen molecules are ionized and injected into the solid electrolyte substrate 2 as oxygen ions. The implanted oxygen ions move toward the electrode film 3 on the upper surface by a supply voltage from the DC power supply 5. The oxygen ions are converted from oxygen ions to molecules in the electrode film 3 and released into the air. In this way, it was operated as an oxygen pump that supplies oxygen upward from the air below the solid electrolyte substrate 2.

  Moreover, as this kind of oxygen supply apparatus, there is one as shown in FIG. 7 (for example, see Patent Document 2).

  As shown in FIG. 7, the oxygen pump element 6 is composed of a first electrode film 8 formed on a porous substrate 7 such as alumina, a thin film 9 of oxygen ion conductor, and a second electrode film 10. The first electrode film 8 has a structure in which platinum fine particles are formed on the porous substrate 7, and the second electrode film 10 is formed by forming a thin film obtained by combining the platinum fine particles with the thin film 9 of the oxygen ion conductor. The heating means 11 is composed of a heater print film 13 formed by patterning a conductive paste on an insulating substrate 12 such as an alumina substrate by screen printing. The heating means 11 is not enclosed in the housing 14 and is in the atmosphere. Arranged in a released state.

In this configuration, when the oxygen pump element 6 is heated to a temperature at which the oxygen pump element 6 operates as an oxygen pump by the heating means 11 and a DC voltage is applied between both electrodes using the first electrode film 8 as a cathode and the second electrode film 10 as an anode, As indicated by the middle arrow, oxygen in the air dissociated and adsorbed on the first electrode film 8 moves as oxygen ions in the thin film 9 of the oxygen ion conductor and is carried to the second electrode film 10 to form oxygen molecules in the atmosphere. Released into. As a result, the oxygen concentration in the container attached to the housing 14 can be reduced.
JP-A-8-67997 JP 2003-215094 A

  However, in each of the conventional configurations, when the solid electrolyte substrate 2 or the porous substrate 7 is enlarged and the area of the electrode film is increased, the driving voltage is several volts and the driving current is several tens of amperes. -There was a problem that it became a high current type and the power supply circuit was very complicated and expensive. In addition, since the substrate is heated by an external heating heater or the like, there are problems such as poor efficiency or a large temperature distribution.

  The present invention solves the above-described conventional problems, and provides a low-current / high-voltage oxygen pump element, and also provides an oxygen supply device with high heating efficiency and excellent temperature distribution characteristics. For the purpose.

  In order to solve the above-mentioned conventional problems, the oxygen pump element of the present invention is provided with a pair of electrode portions constituting a plurality of capacitors on an oxygen ion conductive solid electrolyte substrate, and the electrode portions are electrically An insulating film is formed in a region where an electrode portion is not provided on one or both sides of the solid electrolyte substrate, and a heater resistor is disposed on the insulating film. is there. In addition, an oxygen supply device is configured using this oxygen pump element.

  As a result, a heater with high heating efficiency can be realized, the temperature distribution of the solid electrolyte substrate can be reduced, and an oxygen pump element and an oxygen supply device excellent in power saving can be realized. In addition, since the plurality of electrode portions are formed of a series circuit, a low current / high voltage type can be realized, and a drive control circuit can be configured at low cost.

  The oxygen pump element of the present invention and the oxygen supply device using the oxygen pump element can realize a heater with high heating efficiency and are excellent in power saving. Furthermore, a low current / high voltage type can be realized, and the drive control circuit can be configured at low cost.

  According to a first aspect of the present invention, a pair of electrode portions constituting a plurality of capacitors is provided on an oxygen ion conductive solid electrolyte substrate, the electrode portions are configured to be electrically connected in series, and the solid electrolyte A heater with high heating efficiency can be obtained by forming an insulating film in a region where no electrode portion is provided on one or both sides of the substrate and then forming an oxygen pump element in which a heater resistor is disposed on the insulating film. In addition, the temperature distribution of the solid electrolyte substrate can be reduced, and an oxygen pump element and an oxygen supply device excellent in power saving can be realized. In addition, since the plurality of electrode portions are formed of a series circuit, a low current / high voltage type can be realized, and a drive control circuit can be configured at low cost.

  According to a second invention, in particular, in the first invention, the electrode portion is composed of a first electrode film directly bonded to the solid electrolyte substrate and a second electrode film formed on the first electrode film, Since one electrode film is a film mainly composed of a composite metal oxide component and the second electrode film is a film mainly composed of a noble metal component, the second electrode film is composed of a highly conductive material. The same potential can be applied to the electrode portion having the following area. Moreover, since the first electrode film can enhance the electrode reaction of dissociating and adsorbing oxygen as an intermediate layer between the solid electrolyte substrate and the second electrode film, it can obtain a good catalytic action for changing from oxygen molecules to oxygen ions. be able to.

  In particular, according to the third invention, in the first or second invention, the solid electrolyte substrate is provided with a plurality of through holes, and the adjacent electrode portions are connected to the electrode portions located on the opposite side via the through holes. Since the plurality of electrode portions can be connected to one side at a time by a method such as screen printing, the manufacturing process at the time of mass production can be simplified.

In particular, according to a fourth invention, in any one of the first to third inventions, the insulating film is a glass ceramic film, and the glass ceramic film is mainly composed of a SiO ₂ —ZnO—CaO—BaO system or SiO ₂ —B. It is a crystallized glass containing 15 to 25 wt% of an alkaline earth metal oxide and 2 wt% or less of an alkali metal oxide in a ₂ O ₃ —MgO—BaO system, and is fired at 900 to 1000 ° C. As a result, the glass ceramic film is crystallized to some extent, and can maintain sufficient adhesion with the solid electrolyte substrate, and can also maintain sufficient insulation between the resistor and the solid electrolyte substrate. Sufficient durability can be obtained even when the resistor is used repeatedly.

  According to a fifth invention, in particular, in any one of the first to third inventions, the insulating film is a clay film, and the clay film has a structure in which crystals are oriented in layers, whereby Sufficient adhesion can be maintained and insulation between the heater resistor and the solid electrolyte substrate can be sufficiently maintained, so that sufficient durability can be obtained even when the heater resistor is used repeatedly. be able to.

  In particular, the sixth invention is any one of the first to third inventions, wherein the insulating film is a composite film of a glass ceramic film and a clay film, the glass ceramic film is disposed on the solid electrolyte substrate, By having the structure in which the clay film is disposed on the glass ceramic film, sufficient adhesion with the solid electrolyte substrate can be maintained, and insulation between the heater resistor and the solid electrolyte substrate is sufficient. Therefore, even when the heater resistor is used repeatedly, sufficient durability can be obtained.

  According to a seventh aspect of the present invention, in particular, in any one of the first to sixth aspects, the heater resistor disposed on the insulating film is overcoated with a glass ceramic film or a clay film. Even when the resistor is repeatedly used, sufficient durability can be obtained.

  According to an eighth invention, in particular, in any one of the first to seventh inventions, a heat conductive film is disposed on a side and a position facing the insulating film with the solid electrolyte substrate interposed therebetween. The generated heat is transferred to the opposite heat conduction film through the solid electrolyte substrate, and can be transferred to the surface of the solid electrolyte substrate well by the heat conduction film, so the solid electrolyte substrate can be rapidly heated. At the same time, it is possible to reduce power consumption during normal operation.

  According to a ninth invention, in particular, in any one of the first to eighth inventions, the solid electrolyte substrate has a configuration in which the outer peripheral portion of the solid electrolyte substrate is coupled to the metal foil member through an insulating film. Since the structure is supported by the support frame via the metal foil member, the outer periphery of the solid electrolyte substrate is not rapidly cooled by the support frame, and the space portion is gas sealed with the solid electrolyte substrate and the metal foil member. And can be partitioned. Moreover, it can buffer with a metal foil member also with respect to the thermal stress which generate | occur | produces in a solid electrolyte substrate. That is, since the solid electrolyte substrate is supported by the support frame via the metal foil member, the risk of cracking of the solid electrolyte substrate can be greatly reduced.

In a tenth aspect of the invention, in particular, in the ninth aspect of the invention, the insulating film is a TiO ₂ film or a ZrO ₂ film formed on the surface of the metal foil member by a liquid phase deposition method. Since the TiO ₂ film or ZrO ₂ film formed on the surface of the metal foil member by the liquid phase deposition method is very thin with respect to the electrolyte substrate, the necessary insulation is maintained without impairing the flexibility of the metal foil member. be able to.

In an eleventh aspect of the invention, in particular, in the ninth aspect of the invention, the insulating film is a glass ceramic film disposed on the outer peripheral portion of the surface of the solid electrolyte substrate, and the main body of the glass ceramic film is SiO ₂ —ZnO—CaO—. A solid electrolyte substrate comprising a BaO-based or SiO ₂ —ZnO—CaO—BaO-based crystallized glass containing 15 to 25 wt% of an alkaline earth metal oxide and 2 wt% or less of an alkali metal oxide. By providing the insulating film on the side, it is possible to maintain necessary insulation between the solid electrolyte substrate and the metal foil member without impairing the flexibility of the metal foil member.

  In the twelfth aspect of the invention, in particular, in any one of the ninth to eleventh aspects of the invention, the metal foil member is exposed to a high temperature for a long time because the conductive film is disposed in a predetermined width. In some cases, oxidative corrosion could be prevented, and the solid electrolyte substrate could be supported stably.

  In a thirteenth aspect of the invention, in particular, in any one of the first to twelfth aspects of the invention, when the solid electrolyte substrate is lanthanum gallate, the lanthanum gallate is a perovskite type composite metal oxide mainly composed of lanthanum and gallium. Yes, and has oxygen ion conductivity at 400 ° C. or higher. Therefore, since sufficient capability can be obtained by maintaining the operating temperature of the oxygen pump element at a relatively low temperature of about 600 ° C., deterioration of the oxygen pump element can be suppressed for a long period of time.

  In a fourteenth aspect of the invention, in particular, in any one of the second to thirteenth aspects of the invention, the composite metal oxide of the first electrode film has a perovskite structure, so that the intermediate layer between the solid electrolyte substrate and the second electrode film Since the electrode reaction for dissociating and adsorbing oxygen can be enhanced, oxygen ion conductivity as an oxygen pump element can be improved.

  In the fifteenth aspect of the invention, in particular, in any one of the ninth to fourteenth aspects of the invention, since the metal foil member is a ferritic stainless steel containing aluminum, it has excellent characteristics against high-temperature oxidation. The characteristics stable for long-term use can be maintained at around 800 ° C.

  In particular, the sixteenth invention is the oxygen pump element according to any one of the first to fifteenth inventions, voltage applying means for applying a voltage to the oxygen pump element, and voltage control means for controlling the voltage applying means. Heating means for applying a voltage to the heater resistor of the oxygen pump element for heating; temperature control means for detecting the solid electrolyte substrate temperature of the oxygen pump element to control the heating means; and the oxygen pump element By providing an oxygen supply device comprising a breathable heat insulating means for preventing thermal diffusion of the gas and a mixing means for mixing oxygen generated through the oxygen pump element with air to form a mixed gas having a predetermined oxygen concentration The solid electrolyte substrate is heated and heated by the heater resistor provided directly on the surface, improving the thermal efficiency of the oxygen pump element and the power energy required for heating the oxygen pump element. Energy can be suppressed to be small, it is possible to achieve energy saving. Moreover, since the whole oxygen pump element can be heated uniformly, the damage prevention effect of the oxygen pump element can be improved. In addition, since the oxygen pump element, the partition means, and the heating means can be a simple structure covered with a heat insulating material having a ventilation function, the oxygen pump can be downsized and can be easily mounted on a device. Can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1 to 4 show an oxygen pump element and an oxygen supply apparatus using the same according to Embodiment 1 of the present invention.

  As shown in FIG. 1 and FIG. 2, the oxygen pump element in the present embodiment is provided with a pair of electrode portions that constitute a plurality of capacitors on an oxygen ion conductive solid electrolyte substrate 15, and the electrode portions are An insulating film 18 is formed in a region where an electrode portion is not provided on one or both sides of the solid electrolyte substrate 15 and is configured to be an electric series circuit, and then a heater resistor is formed on the insulating film 18. 19 is provided. The electrode portion includes first electrode films 16 and 17 directly bonded to the solid electrolyte substrate 15 and second electrode films 20 and 21 formed on the first electrode films 16 and 17. The electrode films 16 and 17 are films mainly composed of a composite metal oxide component, and the second electrode films 20 and 21 are films mainly composed of a noble metal component.

The solid electrolyte substrate 15 is formed by molding a sintered body of substitutional type lanthanum gallate (La _0.8 Sr _0.2 Ga _0.8 Mg _0.2 O ₃ ) into a flat plate having an arbitrary thickness, specifically, a dimension φ120 mm, The thickness is 200 μm. On the surface of the solid electrolyte substrate 15, the first electrode films 16 are disposed as 28 positive electrode films (1) to (28) so as to be concentric and substantially symmetrical. The electrode films arranged at concentric positions are located at almost equal intervals, and the distance between the electrode films is laid out in consideration of the potential when applied to the electrode films. Similarly, the first electrode film 17 is provided as 28 negative electrode films on the back surface of the solid electrolyte substrate 15, and the positions thereof are pairs that form a plurality of capacitors on the solid electrolyte substrate 15. It is. The individual first electrode films 16 and 17 are designed with about 2 cm ² as a guide, and the total area of the electrode portion with respect to the solid electrolyte substrate 15 is about 56 cm ² .

The first electrode films 16 and 17 are films mainly composed of a composite metal oxide component, and a perovskite complex oxide having conductivity is used. Specifically, a paste prepared by mixing Sm _0.5 Sr _0.5 CoO ₃ with a cellulose-based vehicle as an organic solvent is formed by screen printing to form a printed film, dried, and then fired at 1100 ° C. A positive and negative electrode film having porosity was formed.

Next, an insulating film 18 was formed on the solid electrolyte substrate 15 by using a portion where the first electrode films 16 and 17 were not provided. A glass ceramic film was used as the insulating film 18. For the glass ceramic film, a crystallized glass containing SiO ₂ —ZnO—CaO—BaO system containing 20 wt% of alkaline earth metal oxide and about 1.0 wt% of alkali metal oxide was used. The glass ceramic material is first melted at 1300 ° C., then processed into a cullet state by a roll cooler, and then further pulverized to a predetermined particle size by a ball mill or the like. The crushed glass particles were processed into a printing paste. Since the crystallization start temperature of crystallized glass is about 850 ° C., after screen printing is performed twice, crystallization proceeds to some extent when fired at 1000 ° C., and a glass ceramic film having a high thermal shock resistance has a film thickness of about 30 μm. Been formed.

  Further, a heater resistor 19 is formed on the glass ceramic film, which is obtained by adding 5 wt% of crystallized glass particles constituting the glass ceramic film to the AgPd (Ag: Pd = 80: 20) paste. I used something. A printed film was formed by screen printing, dried and then fired at 900 ° C.

  Next, a porous Au conductive film was laminated as the second electrode films 20 and 21 on the surfaces of the 28 first electrode films 16 and 17, respectively. In this case, a printed film was formed by screen printing using Au paste, dried, and baked at 800 ° C. to form a conductive film having a thickness of about 3 μm. At this time, the lead part printing for the plurality of second electrode films 20 to form a series circuit structure with the second electrode film 21 on the opposite side via the solid electrolyte substrate 15 was also performed at the same time. In the lead portion printing, the solid electrolyte substrate 15 was printed many times so that the film thickness was substantially the same as that of the first electrode film + the second electrode film. Thereafter, the plurality of through holes 22 provided in the solid electrolyte substrate 15 was also filled with Au paste to form a circuit.

  As shown in FIG. 2, the through-hole 22 allows adjacent electrode portions to be connected to an electrode portion located on the opposite side via the through-hole 22, whereby the electrode portion is connected to the series circuit. It comprised so that it might become. That is, the through-hole 22 is provided in the solid electrolyte substrate 15 between the adjacent second electrode films, and the lead portion taken out from the positive electrode side conductive film is disposed to the intermediate position between the adjacent positive electrode side and negative electrode side conductive film. The lead portion from the negative electrode side conductive film is connected through the through hole 22 covered with Au. As a result, 28 electrode portions are configured in a series circuit. The specific order of the electrode parts is shown as (1) to (28) on the electrode part in FIG. Accordingly, in the present embodiment, a potential gradient is generated from the outer peripheral portion of the solid electrolyte substrate 15 to the central portion.

The second electrode films 20 and 21 can improve the surface distribution unevenness of the electrode portion with respect to the potential when a voltage of about 1 to 1.5 V is applied between each pair of positive and negative electrode films. The maximum potential unevenness was within about 7% with respect to the electrode area of 2 cm ² . Furthermore, the heat generated by the heater resistor 19 can be favorably conducted to the entire surface of the solid electrolyte substrate 15.

  As shown in FIG. 3, the outer periphery of the body electrolyte substrate 15 is coupled to an annular metal foil member 23 via an insulating film 24. As the metal foil member 23, Fe-20Cr-5Al, 10 μm was used. An insulating film 24 made of a glass ceramic film is formed on a portion of the solid electrolyte substrate 15 in contact with the metal foil member 23. The insulating film 24 has the same composition as that of the insulating film 18, but the screen printing is performed once and the film thickness is about 15 μm. In addition, a conductive film having a predetermined width is disposed at the joint between the metal foil member 23 and the solid electrolyte substrate 15, and Au paste is screen-printed with a width of 3 mm on both inner peripheral surfaces of the metal foil member 23, thereby solid electrolyte. Au paste was also screen-printed on the joint portion of the substrate 15 and baked at 800 ° C. while applying a predetermined load after drying. As a result, the conductive films 25 and 26 are also disposed on the metal foil member 23.

  A lead member (not shown) is connected from the order (1) of the second electrode film 20 (positive electrode side conductive film), and a lead member (not shown) from the order (1) of the second electrode film 21 (negative electrode side conductive film). ) Is connected.

  FIG. 4 shows an oxygen supply apparatus using the oxygen pump element shown in FIGS.

  The periphery of the metal foil member 23 is fixed to the support 28 with an electrically insulating gas sealant 27. The solid electrolyte substrate 15 is fixed to the support 28 via the metal foil member 23. The space partition means is composed of a solid electrolyte substrate 15 and a metal foil member 23.

  A voltage applying means 30 is connected to the positive electrode side conductive film side of the second electrode film 20 and the negative electrode side conductive film side of the second electrode film 21 via a lead member 29. The voltage control means 31 is connected.

  The heating means 32 is connected to the lead member 33 for applying a voltage to the heater resistor 19 of the oxygen pump element, and the temperature control means 34 having means 34 a for detecting the temperature of the solid electrolyte substrate 15 sends a signal to the heating means 32. Is sending.

  The means 34a for detecting the temperature of the solid electrolyte substrate 15 may be a temperature sensor or another method. In the case of a temperature sensor, the temperature sensor may be disposed in the vicinity of the solid electrolyte substrate 15 or may be disposed at an arbitrary position. The temperature control unit 34 controls the input to the heater resistor 19 via the heating unit 32 according to the temperature of the solid electrolyte substrate 15 detected by the temperature control unit 34.

  The heat insulating means 35 and 36 are air-permeable heat insulating members for suppressing heat loss generated in the heater resistor 19. Here, the heat insulating material shape | molded in the flat form which has a silica and an alumina as a main component was used. Each element constituting the oxygen supply device and the container 37 for maintaining the overall shape are provided with an opening 38 for ventilation on the second electrode film 21 side. A gas mixing means 40 is connected to the second electrode film 20 side of the container 37 through a vent 39. The mixing means 40 includes a gas induction pipe 41, a mixed gas introduction pipe 42, a gas mixer 43, and a gas pump 44.

  About the oxygen supply apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, the oxygen supply device is placed in the atmosphere such as room air. At this time, atmospheric components such as nitrogen and oxygen (hereinafter simply referred to as nitrogen and oxygen) pass through the inside of the heat insulating means 35 and 36, which are air-permeable heat insulating materials constituting the oxygen supply device, to form the second electrode film. It is stable in a state where it has diffused to the surface on the 20th and 21st side.

  In this state, when the heater resistor 19 is energized by the temperature control means 34, the temperature of the solid electrolyte substrate 15 in the heat insulation means 35 and 36 rises. The temperature control means 34 energizes while controlling the heater resistor 19 so that the temperature required for the operation of the solid electrolyte substrate 15 is about 600 ° C. However, this temperature is not limited, and operation at an arbitrary temperature is possible according to the characteristics of the solid electrolyte substrate 15. In this case, by using 70 W of power for the heater resistor 19, the solid electrolyte substrate 15 could be brought to 600 ° C. in about 60 seconds. Moreover, the electric power required in order to maintain 600 degreeC in the steady state was 43W.

  When a voltage of about 28 to 30 V is applied to the solid electrolyte substrate 15 through the second electrode films 20 and 21 when the temperature at which the solid electrolyte substrate 15 can conduct oxygen ions is reached, the surface on the second electrode film 21 side Oxygen in the vicinity moves from the negative electrode side conductive film and the negative electrode side conductive film to the positive electrode side conductive film as the second electrode film 20 from the negative electrode side conductive film and oxygen ions inside the solid electrolyte substrate 15 by an electrochemical reaction. Released from the surface on the side as recombined oxygen molecules.

  At this time, a current of about 4 A flows between the electrode portions of the solid electrolyte substrate 15, and the solid electrolyte substrate 15 self-heats. Therefore, the metal foil member 23 to be used is also exposed to an ambient temperature of 600 ° C. Since the metal foil member 23 is bonded to the solid electrolyte substrate 15 via the insulating film 24 and the conductive films 25 and 26, current does not leak to the metal foil member 23 side. By providing the insulating film 24 on the solid electrolyte substrate 15 side, it was possible to maintain the necessary insulation between the solid electrolyte substrate 15 and the metal foil member 23 without impairing the flexibility of the metal foil member 23.

  In addition, the formation of the conductive films 25 and 26 could effectively protect against the surface oxidation of the metal foil member 23. Thus, in order to form the conductive films 25 and 26 on the surface of the metal foil member 23 and prevent high-temperature oxidation, at least 3 mm width in the outer peripheral direction from the joint portion with the second electrode films 20 and 21 is required. It was necessary. Further, even if the width is too wide, waste of expensive material is caused. Therefore, practically, the conductive films 25 and 26 formed on the surface of the metal foil member 23 preferably have a width of 3 to 5 mm. Conceivable.

  Here, the vicinity of the surface of the positive electrode-side conductive film of the second electrode film 20 is in a state close to pure oxygen. However, as long as gas leakage cannot be completely prevented, the oxygen is discharged while leaving the surface of the positive-electrode-side conductive film. Is naturally mixed with the leaked gas. Therefore, the metal foil member 23 and the gas sealant 27 which are means for partitioning the space effectively act as means for preventing gas leakage from the negative electrode film side of the second electrode film 21.

  On the other hand, nitrogen is left on the second electrode film 21 side. The remaining nitrogen diffuses into the atmosphere due to the air permeability of the heat insulating means 35, and new oxygen is supplied from the outside to the second electrode film 21 side.

  The oxygen gas released from the second electrode film 20 passes through the vent 39 and constitutes a gas mixing means 40, thereby being covered by the gas induction pipe 41, the mixed gas introduction pipe 42, and the gas mixer 43. Mixed with mixed gas. In the present embodiment, the mixed gas is the atmosphere. The generated mixed gas is an oxygen-enriched gas, and its flow rate is determined by the suction and discharge speed of the gas pump 44.

  The oxygen concentration in the mixed gas is determined by the mixed gas flow rate and the amount of oxygen ions flowing through the solid electrolyte substrate 15, that is, the magnitude of the ionic current. The ionic current can be controlled by the magnitude of the voltage applied to the solid electrolyte substrate 15.

  Finally, the oxygen concentration in the mixed gas obtained by the oxygen supply device is executed by voltage control by the voltage control means 31 and control of the mixed gas flow rate by the gas pump 44.

  As described above, in the present embodiment, the solid electrolyte substrate 15 and the second electrode films 20 and 21 are coupled so as to exhibit oxygen ion conductivity, and the space portion is partitioned by the partitioning means via the solid electrolyte substrate 15. By suppressing the gas leak, heating and raising the temperature and applying a voltage, oxygen molecules are released from the second electrode film 20 to generate an oxygen-enriched mixed gas. The voltage control by the voltage control means 31 and the gas pump By controlling the mixed gas flow rate by 44, an arbitrary oxygen concentration gas can be stably obtained. Specifically, according to the present embodiment, the oxygen concentration can be varied up to 90% based on an oxygen concentration of 30% and a flow rate of 3 L / min. At this time, the electrical circuit of the oxygen pump element may be 28V, 4A specification, and it can be made cheaper in terms of control compared to the parallel circuit.

  As a comparative example to the present embodiment, when a solid electrolyte substrate 15 having the same size is indirectly heated by a ribbon heater, the solid electrolyte substrate 15 is used even when 150 W of electric power is used for the ribbon heater at the time of startup. It took about 90 seconds to bring the temperature to 600 ° C., and when the temperature was raised beyond that, the solid electrolyte substrate 15 was cracked. Moreover, the electric power required for maintaining at 600 degreeC in a steady state was also 95W.

  Although the case where the insulating film 18 and the heater resistor 19 are disposed on one side of the solid electrolyte substrate 15 has been described, both sides may be provided.

(Embodiment 2)
FIG. 5 shows an oxygen pump element according to Embodiment 2 of the present invention. Since the basic configuration overlaps with that of the first embodiment, a description will be given of different portions.

  In the present embodiment, the positive electrode film and the negative electrode film that form the first electrode films 46 and 47 with respect to the solid electrolyte substrate 45 are arranged in a pair structure that constitutes a capacitor with the solid electrolyte substrate 45 interposed therebetween. It is installed. The material composition of the first electrode films 46 and 47 is the same as that of the first embodiment.

  A clay film was disposed as an insulating film 48 in a portion where the electrode on the first electrode film 46 side was not provided. The clay film was made of clay particles, made into a green sheet with 2 μm or less and an organic binder, and then forcibly highly oriented clay particles by a pressing method. That is, the clay film has a structure in which crystals are oriented in layers. Further, after cutting the green sheet pressed into a predetermined shape, the clay film and the solid electrolyte substrate 45 were joined by heat treatment on the solid electrolyte substrate 45. Further, the conductive film 49 was screen-printed and heat-treated so as not to contact the negative electrode film on the side where the clay film was not disposed across the solid electrolyte substrate 45. As the material of the conductive film 49, Au paste was used. Next, the heater resistor 50 was disposed on the clay film 48. The composition of the heater resistor 50 is the same as that of the first embodiment. A glass ceramic film 51 for overcoating the heater resistor 50 is disposed on the heater resistor 50. The glass ceramic film 51 is the same as that used in the first embodiment. Then, the positive electrode side electrically conductive film and the negative electrode side electrically conductive film used as the 2nd electrode films 52 and 53 were arrange | positioned. The composition is the same as in the first embodiment.

As the metal foil member 54 connected to the solid electrolyte substrate 45, a metal foil member 54 having a ZrO ₂ film treated on both surfaces thereof was used. The solid electrolyte substrate 45 and the metal foil member 54 were joined by screen-printing Au paste on both sides of the solid electrolyte substrate 45 and the metal foil member 54 to be joined, and performing heat treatment while applying a predetermined load after drying. . The insulation between the solid electrolyte substrate 45 and the metal foil member 54 is maintained by the ZrO ₂ film formed on the surface of the metal foil member. For the ZrO ₂ film, a liquid phase deposition method was used in which an oxide film was formed by immersing the metal foil member 54 in the treatment aqueous solution. The obtained ZrO ₂ film was able to maintain sufficient insulation properties with a thickness of 0.3 to 0.7 μm and also maintained flexibility as an original metal foil.

  In the oxygen pump element of the present embodiment, when a voltage is applied to the heater resistor 50 and the temperature rises, the solid electrolyte substrate 45 is as thin as 200 μm, so that the heat generated in the heater resistor 50 is the conductive film 49 on the back side. Heat was immediately transferred to the surface, and then the heat could be quickly transferred to the surface of the solid electrolyte substrate 45 by the conductive film 49. As a result, it was possible to bring the solid electrolyte substrate 45 to 600 ° C. in about 50 seconds by using 70 W of power for the heater resistor 50 in the rising characteristics. Moreover, the electric power required for maintaining at 600 degreeC in a steady state was also 85W.

  Furthermore, by overcoating the heater resistor 50 with the glass ceramic film 51, heat dissipation of the heater resistor 50 can be suppressed, and repeated durability for the heater resistor 50 can be improved.

In the present embodiment, when the insulating film 48 is a glass ceramic film, the glass ceramic film contains an SiO ₂ —ZnO—CaO—BaO-based alkaline earth metal oxide in an amount of 15 to 25 wt%, and the alkali metal oxide However, the present invention is not limited to this. Any material can be used as long as it can maintain sufficient insulation with the metal foil member 54 and does not cause a problem in the material used for the conductive film 55 and the heater resistor 50 and the processing temperature in the manufacturing process. In addition, a SiO ₂ —B ₂ O ₃ —MgO—BaO system was also applicable. By suppressing the oxide content of the alkali metal, the properties of the glass are increased in temperature, and the crystallization start temperature can be set at 750 to 800 ° C. by setting the content of the alkaline earth metal oxide to 15 to 25 wt%. It was.

  It is also possible to combine the clay film and the glass ceramic film used in this embodiment mode. In that case, a glass ceramic film may be printed on the solid electrolyte substrate 45, a clay film having a predetermined shape may be placed thereon, and heat treatment may be performed simultaneously.

  In the present embodiment, lanthanum gallate is used as the solid electrolyte substrate 45, but the solid electrolyte substrate 45 is not limited thereto, and may be yttrium-doped zirconia (YSZ), samarium-doped ceria (SDC), or the like. . However, at present, the lanthanum gallate material is the most preferable material in view of the durability of the material because the operating temperature is low as an oxygen ion conductor.

In this embodiment, Sm _0.5 Sr _0.5 CoO ₃ is used as the composite metal oxide of the first electrode films 46 and 47, but the present invention is not limited to this. However, since the composite metal oxide having a perovskite structure has high electrode reactivity with oxygen molecules and itself has conductivity, excellent oxygen ion conductivity can be realized. In particular, among the perovskite complex oxides, those composed of at least one of lanthanum and samarium at the A site and at least one of cobalt, iron, and manganese at the B site, and a part of the A site replaced with strontium It had excellent conductivity and high oxygen molecule electrode reactivity.

  In the present embodiment, Au is used as the noble metal component of the second electrode films 52 and 53, but the present invention is not limited to this. In addition, Ag alone or an Ag—Pd alloy can be used.

  In the present embodiment, the Fe-20Cr-5Al material is used as the metal foil member 54. However, the present invention is not limited to this, and any other metal foil material may be used as long as the material has durability against high-temperature oxidation. Can be used. However, at present, ferritic stainless steel containing aluminum has excellent characteristics against high-temperature oxidation. Furthermore, it is possible to add a rare earth metal for the purpose of improving high temperature oxidation resistance. Moreover, although 10 micrometers in thickness was used, it is thought that 5-15 micrometers is preferable as the metal foil member 54. FIG. In other words, it is preferable that the thickness is as small as possible so that the heat generated in the solid electrolyte substrate 45 is not diffused toward the outer peripheral portion. However, if the thickness is 5 μm or less, the handling at the time of manufacture becomes worse.

Further, in the present embodiment, the metal foil member 54 in which a ZrO ₂ film is formed by the liquid phase deposition method is used, but the present invention is not limited to this. In addition, a TiO ₂ film and an Al ₂ O ₃ film can be used. These were able to form a thin oxide film by being immersed in a treatment aqueous solution, and were able to obtain sufficient insulation even under a high temperature atmosphere in which an oxygen pump was operated.

  As described above, the oxygen pump element and the oxygen supply device using the oxygen pump element according to the present invention can obtain stable and good electric current characteristics over a long period of time. Applicable to a wide range of applications such as health promotion equipment and health promotion equipment.

The top view of the oxygen pump element in Embodiment 1 of this invention Sectional view along the A-A 'line of FIG. Sectional view along line B-B ' Sectional view of an oxygen supply device using the oxygen pump element Sectional drawing of the oxygen pump element in Embodiment 2 of this invention Configuration diagram showing a conventional oxygen pump element Sectional view of a conventional oxygen supply device

Explanation of symbols

15, 45 Solid electrolyte substrate 16, 46 First electrode film (positive electrode film)
17, 47 First electrode film (negative electrode film)
18, 24, 48 Insulating film 19, 50 Heater resistor 20, 52 Second electrode film (positive electrode side conductive film)
21, 53 Second electrode film (negative electrode side conductive film)
22 Through-holes 23, 54 Metal foil members 25, 26, 55 Conductive film 30 Voltage application means 31 Voltage control means 32 Heating means 34 Temperature control means 35, 36 Heat insulation means 40 Mixing means 48 Clay film

Claims (16)

A pair of electrode portions constituting a plurality of capacitors are provided on an oxygen ion conductive solid electrolyte substrate, and the electrode portions are configured to be electrically connected in series, on one side or both sides of the solid electrolyte substrate. An oxygen pump element in which an insulating film is formed in a region where no electrode portion is provided, and a heater resistor is disposed on the insulating film. The electrode part is composed of a first electrode film directly bonded to the solid electrolyte substrate and a second electrode film formed on the first electrode film, and the first electrode film is a film mainly composed of a composite metal oxide component. The oxygen pump element according to claim 1, wherein the second electrode film is a film mainly composed of a noble metal component. The solid electrolyte substrate is provided with a plurality of through holes, and adjacent electrode portions are connected to an electrode portion located on the opposite side via the through holes to form a series circuit. Oxygen pump element. The insulating film is a glass ceramic film, and the main component of the glass ceramic film is SiO ₂ —ZnO—CaO—BaO type or SiO ₂ —B ₂ O ₃ —MgO—BaO type, and an alkaline earth metal oxide is 15 to 25 wt%. The oxygen pump element according to claim 1, wherein the oxygen pump element is a crystallized glass containing 2 wt% or less of an alkali metal oxide. The oxygen pump element according to any one of claims 1 to 3, wherein the insulating film is a clay film, and the clay film has a structure in which crystals are oriented in layers. The insulating film is a composite film of a glass ceramic film and a clay film, and has a structure in which a glass ceramic film is disposed on a solid electrolyte substrate and the clay film is disposed on the glass ceramic film. The oxygen pump element according to any one of the above. The oxygen pump element according to any one of claims 1 to 6, wherein the heater resistor disposed on the insulating film is overcoated with a glass ceramic film or a clay film. The oxygen pump element according to any one of claims 1 to 7, wherein a heat conductive film is disposed on a side and a position facing the insulating film across the solid electrolyte substrate. The oxygen pump element according to any one of claims 1 to 8, wherein the outer peripheral portion of the solid electrolyte substrate is coupled to a metal foil member via an insulating film. The oxygen pump element according to claim 9, wherein the insulating film is a TiO ₂ film or a ZrO ₂ film formed on the surface of the metal foil member by a liquid phase deposition method. The insulating film is a glass ceramic film disposed on the outer periphery of the surface of the solid electrolyte substrate. The glass ceramic film is mainly composed of a SiO ₂ —ZnO—CaO—BaO system or a SiO ₂ —ZnO—CaO—BaO system and is alkaline. The oxygen pump element according to claim 9, which is a crystallized glass containing 15 to 25 wt% of an earth metal oxide and 2 wt% or less of an alkali metal oxide. The oxygen pump element according to any one of claims 9 to 11, wherein the metal foil member is provided with a conductive film having a predetermined width. The oxygen pump element according to claim 1, wherein the solid electrolyte substrate is lanthanum gallate. The oxygen pump element according to any one of claims 2 to 13, wherein the composite metal oxide of the first electrode film has a perovskite structure. The oxygen pump element according to any one of claims 9 to 14, wherein the metal foil member is ferritic stainless steel containing aluminum. The oxygen pump element according to any one of claims 1 to 15, voltage application means for applying a voltage to the oxygen pump element, voltage control means for controlling the voltage application means, and a heater for the oxygen pump element A heating means for applying a voltage to the resistor for heating, a temperature control means for detecting the solid electrolyte temperature of the oxygen pump element to control the heating means, and a breathability for preventing thermal diffusion of the oxygen pump element An oxygen supply device comprising: a heat insulating means; and a mixing means for mixing oxygen generated through the oxygen pump element with air to form a mixed gas having a predetermined oxygen concentration.