Cell frame and cell of internal-manifold-type electrolytic tank, and internal-manifold-type electrolytic tank

Abstract

Provided is a cell frame of an internal-manifold-type electrolytic tank with which it is possible to prevent any reduction in electrolytic efficiency. In a cell frame 4 of an internal-manifold-type electrolytic tank, there are formed an accommodation opening 10 capable of accommodating a partition wall demarcating an electrode chamber, a supply passage for supplying an electrode liquid to the electrode chamber, and a discharge passage 14 for discharging the electrode liquid and a generated gas from the electrode chamber. The supply passage includes a supply opening disposed below the accommodation opening 10, and a supply recess via which the supply opening and the accommodation opening 10 communicate. The discharge passage 14 includes a discharge opening 20a disposed above the accommodation opening 10, and a discharge recess 22a via which the discharge opening 20a and the accommodation opening 10 communicate. The discharge recess 22a has a gas-liquid separation promotion part 24a extending along the accommodation opening 10 so as to be adjacent to the accommodation opening 10.

Description

Cell frame and cell of internal manifold type electrolytic cell, and internal manifold type electrolytic cell

[0001] The present invention relates to a cell frame and a cell of an internal manifold type electrolytic cell, and to an internal manifold type electrolytic cell.

[0002] A bipolar electrolytic cell comprising a plurality of cells is known as an apparatus for producing required gases such as hydrogen gas and oxygen gas. Each cell of the electrolytic cell comprises a partition wall that separates an electrode chamber, an electrode attached to the partition wall, and a cell frame that supports the partition wall. The plurality of cells are aligned in a predetermined direction, and the aligned plurality of cells are pressed by a press device to form the bipolar electrolytic cell.

[0003] Bipolar electrolytic cells are classified into external manifold type and internal manifold type. In an external manifold type electrolytic cell, a supply manifold for supplying electrode solution to the electrode chamber of each cell and a discharge manifold for discharging the electrode solution and generated gas from the electrode chamber of each cell are provided outside each cell. The supply manifold includes a supply pipe disposed adjacent to each cell and a plurality of supply hoses extending from the supply pipe to the electrode chamber of each cell. The discharge manifold includes a discharge pipe disposed adjacent to each cell and a plurality of discharge hoses connected from the discharge pipe to the electrode chamber of each cell.

[0004] On the other hand, in an internal manifold type electrolytic cell, a supply manifold and a discharge manifold are provided inside each cell. The cell frame of the internal manifold type electrolytic cell is formed with an accommodation opening capable of accommodating a partition wall, a supply path for supplying the electrode solution to the electrode chamber, and a discharge path for discharging the electrode solution and the generated gas from the electrode chamber. The supply path includes a supply opening disposed below the accommodation opening and a supply recess communicating with the supply opening and the accommodation opening. The discharge path includes a discharge opening disposed above the accommodation opening and a discharge recess communicating with the discharge opening and the accommodation opening. When multiple cells are clamped by a press device, the supply openings of the cell frames communicate with each other to form a supply manifold, and the discharge openings of the cell frames communicate with each other to form a discharge manifold (see, for example, Patent Document 1).

[0005] Japanese Patent Application Publication No. 8-239788

[0006] In an internal manifold-type electrolytic cell, a gas-liquid separation chamber is not provided in each cell due to space constraints, and therefore, there is a problem that the gas generated as a large number of bubbles tends to accumulate in the electrode chamber. If a gas-liquid separation chamber were provided in each cell of an internal manifold-type electrolytic cell, either an increase in the size of the cell frame or a decrease in the electrode area would be required. Therefore, to avoid an increase in the size of the cell frame or a decrease in the electrode area, the electrode solution and the generated gas are separated (gas-liquid separation) in a tank installed downstream of the internal manifold-type electrolytic cell. However, because the distance that the electrode solution and the generated gas travel to reach the tank serving as the gas-liquid separation chamber is long, in an internal manifold-type electrolytic cell, the gas generated as a large number of bubbles tends to flow poorly and tend to accumulate in the electrode chamber.

[0007] The retention of produced gas in the electrode chamber may cause a decrease in electrolysis efficiency. When produced gas is retained in the electrode chamber, the flow of the electrode solution in the electrode chamber becomes uneven, resulting in a difference in concentration of the electrode solution in the electrode chamber. If the difference in concentration of the electrode solution becomes large, the current distribution becomes uneven, and the electrolysis efficiency decreases. Note that this problem can occur not only in alkaline water electrolytic cells for producing hydrogen gas and oxygen gas, but also in other electrolytic cells, such as sodium chloride electrolytic cells for producing hydrogen gas, chlorine gas, and caustic soda.

[0008] An object of the present invention is to provide a cell frame and cell for an internal manifold type electrolytic cell, and an internal manifold type electrolytic cell, which are capable of preventing a decrease in electrolysis efficiency.

[0009] According to the present invention, the following cell frame for an internal manifold type electrolytic cell is provided to solve the above-mentioned problems. That is, there is provided a "cell frame for an internal manifold type electrolytic cell, which is formed with an accommodation opening capable of accommodating a partition wall that separates an electrode chamber, a supply path for supplying electrode solution to the electrode chamber, and a discharge path for discharging the electrode solution and generated gas from the electrode chamber, the supply path including a supply opening disposed below the accommodation opening and a supply recess communicating with the supply opening and the accommodation opening, the discharge path including a discharge opening disposed above the accommodation opening and a discharge recess communicating with the discharge opening and the accommodation opening, and the discharge recess having a gas-liquid separation promoting portion adjacent to the accommodation opening and extending along the accommodation opening."

[0010] Preferably, the length of the gas-liquid separation promoting portion in the direction along the accommodation opening is between ¼ and ½ of the peripheral length of the accommodation opening. It is desirable that the accommodation opening be circular and the gas-liquid separation promoting portion be arc-shaped.

[0011] The electrode chamber may include an anode chamber and a cathode chamber, the supply path may include an anode-side supply path for supplying anolyte to the anode chamber and a cathode-side supply path for supplying cathode liquid to the cathode chamber, the discharge path may include an anode-side discharge path for discharging the anolyte and an anode produced gas from the anode chamber and a cathode-side discharge path for discharging the cathode liquid and the cathode produced gas from the cathode chamber, and the gas-liquid separation promoting unit may be provided in at least one of the anode-side discharge path or the cathode-side discharge path.

[0012] Furthermore, according to the present invention, there is provided the following cell of an internal manifold type electrolytic cell that solves the above-mentioned problems. That is, there is provided "a cell of an internal manifold type electrolytic cell, comprising the above-mentioned cell frame, a supply-side cover plate that covers the supply recess, and a discharge-side cover plate that covers the discharge recess, wherein the cell frame has a supply-side support recess that is shallower than the supply recess formed adjacent to the supply recess, and a discharge-side support recess that is shallower than the discharge recess formed adjacent to the discharge recess, the supply-side support recess supports the inner surface of the supply-side cover plate, and the discharge-side support recess supports the inner surface of the discharge-side cover plate, and the outer surface of the supply-side cover plate and the outer surface of the discharge-side cover plate are located on the same plane as the surfaces of the cell frame in the portions where the supply recess, the supply-side support recess, the discharge recess, and the discharge-side support recess are not formed."

[0013] It is preferable that the supply recess has a plurality of supply side support protrusions attached thereto at intervals from each other, which, together with the supply side support recess, support the inner surface of the supply side cover plate, and that the discharge recess has a plurality of discharge side support protrusions attached thereto at intervals from each other, which, together with the discharge side support recess, support the inner surface of the discharge side cover plate.

[0014] The supply-side cover plate and the discharge-side cover plate may be joined to the cell frame by welding. It is convenient that the supply-side support recess has a joining portion extending in a direction away from the storage opening, the supply-side cover plate has a joined portion extending in a direction away from the storage opening, and the joined portion of the supply-side cover plate is joined to the joining portion of the supply-side support recess by welding. The discharge-side support recess may have a joining portion extending in a direction away from the storage opening, the discharge-side cover plate has a joined portion extending in a direction away from the storage opening, and the joined portion of the discharge-side cover plate may be joined to the joining portion of the discharge-side support recess by welding.

[0015] The supply-side support recess and the discharge-side support recess may be connected, and the supply-side cover plate and the discharge-side cover plate may be integrally formed.

[0016] It is desirable that a partition wall is fixed to the storage opening of the cell frame, the partition wall having a first main surface and a second main surface located opposite to the first main surface, a first current collector, a first electrode, and a membrane arranged on the first main surface side of the partition wall in this order from the side closest to the first main surface, and a second current collector, a cushion material, and a second electrode arranged on the second main surface side of the partition wall in this order from the side closest to the second main surface, and that a gasket be attached to the cell frame to sandwich the peripheral portion of the membrane together with the cell frame, the supply-side cover plate, and the discharge-side cover plate.

[0017] Furthermore, according to the present invention, there is provided the following internal manifold type electrolytic cell that solves the above-mentioned problems: "An internal manifold type electrolytic cell in which a plurality of cells as described above are aligned in a predetermined direction, wherein the cell frame has a first main surface and a second main surface located opposite to the first main surface, the first main surface of the cell frame faces the second main surface of the cell frame between adjacent cells, the supply openings of the cell frames communicate with each other to form a supply manifold, and the discharge openings of the cell frames communicate with each other to form a discharge manifold."

[0018] In the present invention, the cell frame is provided with a gas-liquid separation promoting section that is adjacent to and extends along the accommodation opening. Therefore, after the electrolysis reaction, the electrode solution and the generated gas are quickly separated in the gas-liquid separation promoting section without increasing the size of the cell frame or reducing the electrode area. Therefore, the flow of the electrode solution in the electrode chamber is made uniform, and the difference in the concentration of the electrode solution in the electrode chamber is prevented from becoming excessively large. As a result, the current distribution is made uniform, and a decrease in electrolysis efficiency is prevented.

[0019] 1. An exploded perspective view of a cell frame, a supply side cover plate, and a discharge side cover plate according to the present invention. 1. A perspective view showing a state in which a supply side cover plate and a discharge side cover plate are attached to the cell frame shown in FIG. 1. 2. A front view of the lower half of the first main surface of the cell frame shown in FIG. 1. 3. An enlarged perspective view of the cell frame and the supply side cover plate shown in FIG. 1. 4. A front view of the lower half of the second main surface of the cell frame shown in FIG. 1. 5. A front view of the upper half of the first main surface of the cell frame shown in FIG. 1. 6. An enlarged perspective view of the cell frame and the discharge side cover plate shown in FIG. 1. 7. A front view of the upper half of the second main surface of the cell frame shown in FIG. 1. 8. A cross-sectional view taken along line IX-IX in FIG. 2. 9. A cross-sectional view taken along line XX in FIG. 2. 10. A perspective view showing a state in which partition walls are fixed to the cell frame shown in FIG. 1. 11. An exploded perspective view of the cell frame to which the partition walls are fixed, and the first and second current collectors. 12. An exploded perspective view of a cell including the cell frame shown in FIG. 12. 13. A perspective view of the cell shown in FIG. 13. 14. A cross-sectional view taken along line XV-XV in FIG. 14. 16. A cross-sectional view taken along line XVI-XVI in Figure 14. An exploded perspective view of a cell frame in which a supply-side support recess and a discharge-side support recess are connected, and a cover plate in which a supply-side cover plate and a discharge-side cover plate are integrally formed. A front view of a cell frame having a rectangular storage opening with rounded corners. A front view of the lower half of the first main surface of a cell frame in which a sealing material is arranged on the first main surface along the periphery of the storage opening. A front view of the upper half of the first main surface of a cell frame in which a sealing material is arranged on the first main surface along the periphery of the storage opening.

[0020] Hereinafter, preferred embodiments of a cell frame and cells of an internal manifold type electrolytic cell according to the present invention, and an internal manifold type electrolytic cell will be described with reference to the drawings.

[0021] (Cell 2) Referring to Figs. 1 and 2, the cell 2 of the internal manifold type electrolytic cell comprises a cell frame 4, a supply side cover plate 6, and a discharge side cover plate 8.

[0022] (Cell Frame 4 of Cell 2) In this embodiment, the cell frame 4 is formed in an overall circular ring shape. However, the cell frame 4 may also be formed in a rectangular ring shape with rectangular outer and inner peripheries. The cell frame 4 is formed in a sheet shape having a first main surface 4a and a second main surface 4b located opposite the first main surface 4a. The material of the cell frame 4 may be an insulating material such as resin, or a conductive material such as metal. If the cell frame 4 is formed from a metal material, the surface of the cell frame 4 may be subjected to a surface treatment such as nickel plating. The cell frame 4 may also be provided with a bracket (not shown) extending radially outward from the outer periphery of the cell frame 4. The thickness of the cell frame 4 may be determined in consideration of the materials and thicknesses of the partition walls 42, the first and second current collectors 46a and 46b, the first and second electrodes 48a and 48b, the cushion material 52, the gaskets 54, etc., which will be described later. For example, the thickness is 3 mm to 50 mm, more preferably 4 mm to 35 mm, and even more preferably 5 mm to 20 mm.

[0023] The cell frame 4 is formed with an accommodation opening 10 capable of accommodating a partition wall 42 described below, a supply path 12 for supplying the electrode solution to the electrode chamber, and a discharge path 14 for discharging the electrode solution and generated gas from the electrode chamber.

[0024] (Accommodation Opening 10 of Cell Frame 4) In this embodiment, the accommodation opening 10 is circular and located in the center of the cell frame 4. A partition wall 42 (see FIG. 11 ), which will be described later, is accommodated in the accommodation opening 10, and the periphery of the accommodation opening 10 is joined to the periphery of the partition wall 42. The periphery of the accommodation opening 10 and the periphery of the partition wall 42 may be joined mechanically using appropriate fasteners such as screws, bolts, or rivets, or may be joined by welding. Welding is a preferred joining method because it eliminates the risk of the fasteners coming off and provides sufficient joint strength for long-term use. The accommodation opening 10 may be rectangular or formed by a combination of straight and curved lines. For example, as shown in FIG. 18 , the accommodation opening 10 may be a square with rounded corners.

[0025] (Supply Channel 12 of Cell Frame 4) The supply channel 12 includes a first supply channel 12a for supplying the first electrode solution to the first electrode chamber 40a (see FIGS. 15 and 16 ) and a second supply channel 12b for supplying the second electrode solution to the second electrode chamber 40b (see FIGS. 15 and 16 ). The first and second electrode chambers 40a, 40b are separated by a partition wall 42, with the first electrode chamber 40a serving as either an anode chamber or a cathode chamber, and the second electrode chamber 40b serving as the other of an anode chamber or a cathode chamber. The first supply channel 12a serves as either an anode-side supply channel for supplying the anode solution to the anode chamber or a cathode-side supply channel for supplying the cathode solution to the cathode chamber, and the second supply channel 12b serves as the other of an anode-side supply channel or a cathode-side supply channel.

[0026] 3 and 4 , the first supply path 12a includes a first supply opening 16a disposed below the accommodation opening 10 and a first supply recess 18a that connects the first supply opening 16a to the accommodation opening 10. The first supply opening 16a extends in the circumferential direction of the cell frame 4 and penetrates the lower part of the cell frame 4. The first supply recess 18a is formed in the first main surface 4a of the cell frame 4. When the multiple cells 2 are sandwiched by the press device, the first supply openings 16a communicate with each other, thereby forming a first supply manifold for supplying the first electrode liquid to the first electrode chambers 40a of each cell 2. The depth of the first supply recess 18a may be determined appropriately taking into consideration the thickness of the cell frame 4, the concentration and flow rate of the first electrode solution, and electrolysis conditions (e.g., current value, temperature, pressure, etc.). For example, the depth is 0.5 mm to 20 mm. From the viewpoint of promoting gas-liquid separation and suppressing a decrease in electrolysis efficiency, the depth of the first supply recess 18a is preferably 1 mm to 8 mm, and more preferably 2 mm to 6 mm. If the depth of the first supply recess 18a is less than 0.5 mm, the supply of the first electrode solution to the first electrode chamber 40a may be impeded. Furthermore, if the depth of the first supply recess 18a is greater than 20 mm, the first electrode solution may not be supplied uniformly to the multiple first electrode chambers 40a. In either case, gas-liquid separation may be hindered, potentially resulting in a decrease in electrolysis efficiency. Furthermore, from the viewpoint of preventing damage to the cell frame 4 due to concentration of force on the first supply recess 18a, which is a relatively thin portion of the cell frame 4, when the electrolytic cell is constructed by sandwiching the multiple cells 2 using a press device, the ratio of the depth of the first supply recess 18a to the thickness of the cell frame 4 is preferably 0.03 to 0.3. Here, the thickness of the cell frame 4 refers to the thickness of the thickest portion of the cell frame 4. Furthermore, the depth of the first supply recess 18a refers to the distance from the bottom of the first supply recess 18a in the thickness direction of the cell frame 4 to the inner surface of the first supply cover plate 6a when the inner surface of the first supply cover plate 6a is supported by the first supply support recess 26a and the first supply support protrusion 28a described below.

[0027] (Second Supply Path 12b) As shown in FIG. 5 , the second supply path 12b, like the first supply path 12a, includes a second supply opening 16b disposed below the storage opening 10 and a second supply recess 18b connecting the second supply opening 16b and the storage opening 10. The second supply opening 16b is disposed circumferentially spaced apart from the first supply opening 16a. The second supply opening 16b also extends circumferentially around the cell frame 4 and penetrates the lower portion of the cell frame 4. In this embodiment, the circumferential length of the second supply opening 16b is the same as the circumferential length of the first supply opening 16a, but this does not have to be the same. The second supply recess 18b is formed in the second main surface 4b of the cell frame 4. In this embodiment, the depth of the second supply recess 18b is the same as the depth of the first supply recess 18a, but this does not have to be the same. If the depth of second supply recess 18b and the depth of first supply recess 18a are the same, this is preferable because, when multiple cells 2 are sandwiched by a press device to form an electrolytic cell, it is possible to prevent force from concentrating on first supply recess 18a or second supply recess 18b, which are relatively thin portions of cell frame 4, and damaging cell frame 4. When multiple cells 2 are sandwiched by the press device, second supply openings 16b communicate with each other, thereby forming a second supply manifold for supplying the second electrode solution to second electrode chambers 40b of each cell 2.

[0028] 6 , the discharge channel 14 has a first discharge channel 14a for discharging the first electrode liquid and the produced gas from the first electrode chamber 40a, and a second discharge channel 14b for discharging the second electrode liquid and the produced gas from the second electrode chamber 40b. The first discharge channel 14a serves as either an anode-side discharge channel for discharging the anolyte and the anode produced gas from the anode chamber or a cathode-side discharge channel for discharging the cathode liquid and the cathode produced gas from the cathode chamber, and the second discharge channel 14b serves as the other of the anode-side discharge channel or the cathode-side discharge channel.

[0029] (First Discharge Path 14a) Referring to FIGS. 6 and 7, the first discharge path 14a includes a first discharge opening 20a disposed above the accommodation opening 10 and a first discharge recess 22a communicating with the accommodation opening 10. The first discharge opening 20a extends circumferentially around the cell frame 4 and penetrates the upper portion of the cell frame 4. The first discharge recess 22a is formed in the first main surface 4a of the cell frame 4. In this embodiment, the depth of the first discharge recess 22a is the same as the depth of the first supply recess 18a, but this does not have to be the same. If the first discharge recess 22a is deeper than the first supply recess 18a, the first electrode solution is less likely to stagnate in the first electrode chamber 40a, and concentration differences in the first electrode solution are less likely to occur in the first electrode chamber 40a. This results in a more uniform current distribution in the first electrode chamber 40a, preventing a decrease in electrolysis efficiency. Here, the depth of the first discharge recess 22a refers to the distance from the bottom of the first discharge recess 22a in the thickness direction of the cell frame 4 to the inner surface of the first discharge-side cover plate 8a when the inner surface of the first discharge-side cover plate 8a is supported by first discharge-side support recesses 30a and first discharge-side support protrusions 32a, which will be described later. When multiple cells 2 are sandwiched by a press device, the first discharge openings 20a communicate with each other, thereby forming a first discharge manifold for discharging the first electrode liquid and the generated gas from the first electrode chambers 40a of each cell 2.

[0030] (First Gas-Liquid Separation Promoting Section 24a of First Discharge Channel 14a) The first discharge recess 22a of the first discharge channel 14a has a first gas-liquid separation promoting section 24a adjacent to and extending along the accommodation opening 10. Therefore, after the electrolytic reaction in the first electrode chamber 40a, the first electrode liquid and the generated gas are quickly separated in the first gas-liquid separation promoting section 24a. In the direction along the accommodation opening 10 (the circumferential direction of the cell frame 4), the length of the first gas-liquid separation promoting section 24a is longer than the length of the first discharge opening 20a. The length of the first gas-liquid separation promoting section 24a in the direction along the accommodation opening 10 can be determined appropriately taking into consideration the electrolysis conditions (e.g., current density, temperature, pressure, amount of electrode liquid supplied per unit time, etc.) and the structure of the cell 2 (e.g., the position and shape of the discharge channel 14, etc.). From the viewpoint of promoting gas-liquid separation over a wide range of the first electrode chamber 40a, the length of the first gas-liquid separation promoting portion 24a in the direction along the accommodation opening 10 is preferably from ¼ to ½, more preferably from 5 / 18 to ½, and even more preferably from ⅓ to ½, of the circumferential length of the accommodation opening 10 (the circumference of the accommodation opening 10). If the length of the first gas-liquid separation promoting portion 24a in the direction along the accommodation opening 10 exceeds ½ of the circumferential length of the accommodation opening 10 (the circumference of the accommodation opening 10), there is a risk of an increase in the electrode solution that does not contribute to the electrolytic reaction. Note that in this embodiment, the accommodation opening 10 is circular, so the shape of the first discharge recess 22a is arc-shaped. However, if the accommodation opening 10 is rectangular, the shape of the first discharge recess 22a will be formed in accordance with the shape of the accommodation opening 10.

[0031] (Second Discharge Path 14b) As shown in FIG. 8 , the second discharge path 14b, like the first discharge path 14a, includes a second discharge opening 20b disposed above the storage opening 10 and a second discharge recess 22b connecting the second discharge opening 20b and the storage opening 10. The second discharge opening 20b is disposed circumferentially spaced apart from the first discharge opening 20a. The second discharge opening 20b extends circumferentially around the cell frame 4 and penetrates the upper portion of the cell frame 4. In this embodiment, the circumferential length of the second discharge opening 20b is the same as the circumferential length of the first discharge opening 20a, but this does not have to be the same. The second discharge recess 22b is formed in the second main surface 4b of the cell frame 4. In this embodiment, the depth of the second discharge recess 22b is the same as the depth of the second supply recess 18b, but this does not have to be the same. If the second discharge recess 22b is deeper than the second supply recess 18b, the second electrode solution is less likely to stagnate in the second electrode chamber 40b, and concentration differences in the second electrode solution are less likely to occur in the second electrode chamber 40b. This results in a more uniform current distribution in the second electrode chamber 40b, preventing a decrease in electrolysis efficiency. Furthermore, although the depth of the second discharge recess 22b is the same as the depth of the first discharge recess 22a in this embodiment, they do not have to be the same. Having the same depth of the second discharge recess 22b and the first discharge recess 22a is preferable because it prevents damage to the cell frame 4 due to force concentration on the first discharge recess 22a or the second discharge recess 22b, which are relatively thin portions of the cell frame 4, when multiple cells 2 are sandwiched by a press device to form an electrolytic cell. Here, the depth of the second discharge recess 22b refers to the distance from the bottom of the second discharge recess 22b in the thickness direction of the cell frame 4 to the inner surface of the second discharge-side cover plate 8b when the inner surface of the second discharge-side cover plate 8b is supported by second discharge-side support recesses 30b and second discharge-side support protrusions 32b described below. When multiple cells 2 are sandwiched by a press device, the second discharge openings 20b communicate with each other, thereby forming a second discharge manifold for discharging the second electrode liquid and the generated gas from the second electrode chambers 40b of each cell 2.

[0032] (Second Gas-Liquid Separation Promoting Section 24b of Second Discharge Channel 14b) Similar to the first discharge recess 22a of the first discharge channel 14a, the second discharge recess 22b of the second discharge channel 14b has a second gas-liquid separation promoting section 24b adjacent to and extending along the accommodation opening 10. Therefore, after the electrolysis reaction in the second electrode chamber 40b, the second electrode liquid and the generated gas are quickly separated in the second gas-liquid separation promoting section 24b. In the direction along the accommodation opening 10 (the circumferential direction of the cell frame 4), the length of the second gas-liquid separation promoting section 24b is longer than the length of the second discharge opening 20b. The length of the second gas-liquid separation promoting section 24b in the direction along the accommodation opening 10 can be determined appropriately taking into consideration the electrolysis conditions (e.g., current density, temperature, pressure, amount of electrode liquid supplied per unit time, etc.) and the structure of the cell 2 (e.g., the position and shape of the discharge channel 14, etc.). From the viewpoint of promoting gas-liquid separation over a wide range of the second electrode chamber 40b, the length of the second gas-liquid separation promoting portion 24b in the direction along the accommodation opening 10 is preferably from ¼ to ½, more preferably from 5 / 18 to ½, and even more preferably from ⅓ to ½, of the circumferential length of the accommodation opening 10 (the circumference of the accommodation opening 10). If the length of the second gas-liquid separation promoting portion 24b in the direction along the accommodation opening 10 exceeds ½ of the circumferential length of the accommodation opening 10 (the circumference of the accommodation opening 10), there is a risk of an increase in the electrode solution that does not contribute to the electrolytic reaction. Note that in this embodiment, the accommodation opening 10 is circular, so the shape of the second discharge recess 22b is arc-shaped. However, if the accommodation opening 10 is rectangular, the shape of the second discharge recess 22b will be formed in accordance with the shape of the accommodation opening 10.

[0033] The ratio (B / A) of the radial width (B) of the first gas-liquid separation promotion section 24a to the radial width (A) of the cell frame 4 is preferably 0.1 or more and 0.6 or less, more preferably 0.15 or more and 0.45 or less. The larger the proportion of the first gas-liquid separation promotion section 24a in the radial direction of the cell frame 4, the higher the gas-liquid separation ability. However, when multiple cells 2 are sandwiched and pressed between the fixed head and the movable head, it tends to be difficult to ensure airtightness between the cells 2. If B / A is within the above range, improved gas-liquid separation ability and airtightness between the cells 2 can be easily ensured. The ratio (C / A) of the radial width (C) of the second gas-liquid separation promotion section 24b to the radial width (A) of the cell frame 4 may be the same value as B / A, or may be different. For the same reason, C / A is preferably 0.1 or more and 0.6 or less, more preferably 0.15 or more and 0.45 or less.

[0034] The cell frame 4 may have both the first and second gas-liquid separation promoting sections 24 a, 24 b as in the present embodiment, or may have either the first or second gas-liquid separation promoting section 24 a, 24 b. That is, the gas-liquid separation promoting section may be provided in at least one of the anode-side discharge channel or the cathode-side discharge channel.

[0035] The cell frame 4 will be further described with reference to Figures 3, 4, 6, and 7. The first main surface 4a of the cell frame 4 is provided with a first supply-side support recess 26a (see Figures 3 and 4), a first supply-side support protrusion 28a (see Figures 3 and 4), a first discharge-side support recess 30a (see Figures 6 and 7), a first discharge-side support protrusion 32a (see Figures 6 and 7), and a first annular protrusion 34a (see Figures 3, 4, 6, and 7).

[0036] 3 and 4 , the first supply-side support recess 26a is formed adjacent to the first supply recess 18a on the first main surface 4a of the cell frame 4. In this embodiment, the first supply-side support recess 26a is provided on one circumferential side and the other circumferential side of the first supply recess 18a. The depth of the first supply-side support recess 26a is shallower than the depth of the first supply recess 18a. The first supply-side support recess 26a supports the inner surface of the first supply-side cover plate 6a, which will be described later.

[0037] (First Supply-Side Support Protrusions 28a of Cell Frame 4) Multiple first supply-side support protrusions 28a are provided in the first supply recess 18a at intervals. In this embodiment, the first supply-side support protrusions 28a extend radially or approximately radially of the cell frame 4. Furthermore, in the thickness direction of the cell frame 4, the tops of the first supply-side support protrusions 28a are aligned with the bottoms of the first supply-side support recesses 26a. The multiple first supply-side support protrusions 28a, together with the first supply-side support recesses 26a, support the inner surface of the first supply-side cover plate 6a. The circumferential and radial lengths of the first supply-side support protrusions 28a and the distance between adjacent first supply-side support protrusions 28a can be appropriately set taking into consideration the circumferential or radial length of the first supply recess 18a, the flow rate or flow speed of the first electrode solution, and the like.

[0038] (First Discharge-Side Support Recess 30a of Cell Frame 4) As shown in FIGS. 6 and 7 , the first discharge-side support recess 30a is formed adjacent to the first discharge recess 22a on the first main surface 4a of the cell frame 4. In this embodiment, the first discharge-side support recess 30a is provided along each of the circumferential end and the other circumferential end of the first discharge recess 22a and the radially outer portion of the first discharge recess 22a. The depth of the first discharge-side support recess 30a is shallower than the depth of the first discharge recess 22a. The first discharge-side support recess 30a supports the inner surface of the first discharge-side cover plate 8a, which will be described later. Note that the first discharge-side support recess 30a in this embodiment has a joint 36a extending in a direction away from the storage opening 10 (in this embodiment, radially outward from the cell frame 4). Multiple joints 36a (four in this embodiment) are provided at intervals around the circumferential direction of the cell frame 4.

[0039] (First Discharge-Side Support Protrusions 32a of Cell Frame 4) Multiple first discharge-side support protrusions 32a are provided in the first discharge recess 22a at intervals from one another. In this embodiment, the first discharge-side support protrusions 32a are provided to extend circumferentially at intervals along the housing opening 10, and are also provided to extend radially or approximately radially at intervals along the first discharge opening 20a. In addition, in the thickness direction of the cell frame 4, the tops of the first discharge-side support protrusions 32a are aligned with the bottoms of the first discharge-side support recesses 30a. The multiple first discharge-side support protrusions 32a, together with the first discharge-side support recess 30a, support the inner surface of the first discharge-side cover plate 8a. The circumferential length and radial length of the first discharge side support protrusion 32a, as well as the distance between adjacent first discharge side support protrusions 32a, can be set appropriately taking into consideration the circumferential length or radial length of the first discharge recess 22a, or the flow rate or flow velocity of the mixed flow of gas and first electrode liquid, etc.

[0040] (First annular protrusion 34a of cell frame 4) The first annular protrusion 34a is arranged on the first main surface 4a of the cell frame 4 radially outward of the first and second supply openings 16a, 16b and the first and second discharge openings 20a, 20b, and extends in the circumferential direction of the cell frame 4. Furthermore, a plurality of first annular protrusions 34a are provided at intervals in the radial direction of the cell frame 4.

[0041] The second main surface 4b of the cell frame 4 will be described with reference to Figures 5 and 8. Similar to the first main surface 4a, the second main surface 4b of the cell frame 4 is provided with a second supply-side support recess 26b (see Figure 5), a second supply-side support protrusion 28b (see Figure 5), a second discharge-side support recess 30b (see Figure 8), a second discharge-side support protrusion 32b (see Figure 8), and a second annular protrusion 34b (see Figures 5 and 8).

[0042] (Second supply-side support recess 26b of cell frame 4) As shown in Fig. 5, the second supply-side support recess 26b is formed adjacent to the second supply recess 18b on the second main surface 4b of the cell frame 4. In this embodiment, the second supply-side support recess 26b is provided on one circumferential side and the other circumferential side of the second supply recess 18b. The depth of the second supply-side support recess 26b is shallower than the depth of the second supply recess 18b. The second supply-side support recess 26b supports the inner surface of the second supply-side cover plate 6b, which will be described later.

[0043] (Second Supply-Side Support Protrusions 28b of Cell Frame 4) Multiple second supply-side support protrusions 28b are provided in the second supply recess 18b at intervals. In this embodiment, the second supply-side support protrusions 28b extend radially or approximately radially of the cell frame 4. Furthermore, in the thickness direction of the cell frame 4, the tops of the second supply-side support protrusions 28b are aligned with the bottoms of the second supply-side support recesses 26b. The multiple second supply-side support protrusions 28b, together with the second supply-side support recesses 26b, support the inner surface of the second supply-side cover plate 6b. The circumferential and radial lengths of the second supply-side support protrusions 28b and the distance between adjacent second supply-side support protrusions 28b can be appropriately set taking into account the circumferential or radial length of the second supply recess 18b, the flow rate or flow speed of the second electrode solution, and the like.

[0044] (Second Discharge-Side Support Recess 30b of Cell Frame 4) As shown in FIG. 8 , the second discharge-side support recess 30b is formed adjacent to the second discharge recess 22b on the second main surface 4b of the cell frame 4. In this embodiment, the second discharge-side support recess 30b is provided along each of the circumferential end and the other circumferential end of the second discharge recess 22b and the radially outer portion of the second discharge recess 22b. The depth of the second discharge-side support recess 30b is shallower than the depth of the second discharge recess 22b. The second discharge-side support recess 30b supports the inner surface of the second discharge-side cover plate 8b, which will be described later. Note that the second discharge-side support recess 30b in this embodiment has a joint 36b extending in a direction away from the storage opening 10 (in this embodiment, radially outward from the cell frame 4). A plurality of joints 36b (four in this embodiment) are provided at intervals around the circumferential direction of the cell frame 4.

[0045] (Second Discharge Side Support Protrusions 32b of Cell Frame 4) Multiple second discharge side support protrusions 32b are provided in the second discharge recess 22b at intervals from one another. In this embodiment, the second discharge side support protrusions 32b are provided to extend circumferentially at intervals along the housing opening 10, and are also provided to extend radially or approximately radially at intervals along the second discharge opening 20b. In addition, in the thickness direction of the cell frame 4, the tops of the second discharge side support protrusions 32b are aligned with the bottoms of the second discharge side support recesses 30b. The multiple second discharge side support protrusions 32b, together with the second discharge side support recess 30b, support the inner surface of the second discharge side cover plate 8b. The circumferential length and radial length of the second discharge side support protrusion 32b, as well as the distance between adjacent second discharge side support protrusions 32b, can be set appropriately taking into consideration the circumferential length or radial length of the second discharge recess 22b, or the flow rate or flow velocity of the mixed flow of gas and second electrode liquid, etc.

[0046] (Second annular protrusion 34b of cell frame 4) The second annular protrusion 34b is arranged on the second main surface 4b of the cell frame 4 radially outward of the first and second supply openings 16a, 16b and the first and second discharge openings 20a, 20b, and extends in the circumferential direction of the cell frame 4. Furthermore, a plurality of second annular protrusions 34b are provided at intervals in the radial direction of the cell frame 4.

[0047] As can be understood from the above description and Figures 3, 5, 6, and 8, in the cell frame 4 of this embodiment, the first main surface 4a and the second main surface 4b are symmetrical. However, the first main surface 4a and the second main surface 4b of the cell frame 4 do not have to be symmetrical.

[0048] (Sealing Material of Cell Frame 4) When multiple cells 2 are sandwiched by a press device to form an electrolytic cell, a gasket 54 (described below) is provided between adjacent cells 2 to prevent leakage of the first and second electrode liquids and the produced gas from the first and second electrode chambers 40a, 40b. In addition to this gasket 54, at least a portion of the sealing material described below may be disposed on the first and second main surfaces 4a, 4b of the cell frame 4. This more effectively prevents mixing of the first electrode liquid (including the produced gas) on the first electrode chamber 40a side and the second electrode liquid (including the produced gas) on the second electrode chamber 40b side. As a result, the purity of the produced gas is further increased. When the following sealing materials are used, from the viewpoints of facilitating installation of the sealing materials and effectively increasing the purity of the generated gas, it is preferable that the following sealing materials be placed along the periphery of the supply opening and the periphery of the discharge opening on either the first or second main surface 4a, 4b of the cell frame 4, and it is even more preferable that the following sealing material be further placed along the periphery of the storage opening 10 in addition to these sealing materials. Note that, as the following sealing materials, for example, O-rings, sheets, gaskets, etc. can be used, but are not limited to these. Furthermore, the material of the sealing material may be, for example, a known elastomer.

[0049] (Sealing Material on the First Main Surface 4a Side: Periphery of the Second Supply Opening 16b) Referring to FIG. 3 , an annular (elliptical) sealing material (not shown) may be disposed on the first main surface 4a of the cell frame 4 along the periphery of the second supply opening 16b of the second supply path 12b. This prevents the second electrode liquid in the second supply path 12b from mixing with the first electrode liquid in the first supply path 12a and / or the first electrode chamber 40a. The sealing material has a shape that surrounds the second supply opening 16b, passes between the accommodation opening 10 and the second supply opening 16b, and passes between the second supply opening 16b and the first annular protrusion 34a. A sealing material disposing portion (e.g., a groove) for disposing the sealing material may be provided on the first main surface 4a along the periphery of the second supply opening 16b.

[0050] (Sealing Material on the First Main Surface 4a Side: Periphery of the Second Discharge Opening 20b) Referring to Figure 6, an annular (elliptical) sealing material (not shown) may be arranged on the first main surface 4a of the cell frame 4 along the periphery of the second discharge opening 20b of the second discharge path 14b. This prevents the second electrode liquid (including the produced gas) in the second discharge path 14b from mixing with the first electrode liquid (including the produced gas) in the first discharge path 14a and / or the first electrode chamber 40a. The sealing material has a shape that surrounds the second discharge opening 20b, passes between the first discharge-side support recess 30a (including the joint portion 36a) and the second discharge opening 20b, and passes between the second discharge opening 20b and the first annular protrusion 34a. The first main surface 4a may be provided with a sealant placement portion (for example, a groove) for placing a sealant along the periphery of the second discharge opening 20b.

[0051] (Sealing Material on the First Main Surface 4a Side: Periphery of the Accommodating Opening 10) As shown in FIGS. 19 and 20 , an annular sealing material 60 may be disposed on the first main surface 4a of the cell frame 4 along the accommodating opening 10. This prevents the first electrode liquid (including the generated gas) passing through the first supply path 12a, the first electrode chamber 40a, and the first discharge path 14a from mixing with the second electrode liquid (including the generated gas) passing through the second supply opening 16b and the second discharge opening 20b. The sealing material 60 passes radially outward from the accommodating opening 10, the first supply-side support recess 26a, the first supply opening 16a, the first discharge-side support recess 30a (including the joint portion 36a), and the first discharge opening 20a. The sealing material 60 also passes radially inward from the first annular protrusion 34a, the second supply opening 16b, and the second discharge opening 20b. The first main surface 4 a may be provided with a sealant placement portion (for example, a groove) along the accommodation opening 10 for placing the sealant 60 .

[0052] (Sealing Material on the Second Main Surface 4b Side: Periphery of the First Supply Opening 16a) Referring to FIG. 5 , an annular (elliptical) sealing material (not shown) may be disposed on the second main surface 4b of the cell frame 4 along the periphery of the first supply opening 16a of the first supply path 12a. This prevents the first electrode liquid in the first supply path 12a from mixing with the second electrode liquid in the second supply path 12b and / or the second electrode chamber 40b. The sealing material has a shape that surrounds the first supply opening 16a, passes between the accommodation opening 10 and the first supply opening 16a, and passes between the first supply opening 16a and the second annular protrusion 34b. A sealing material disposing portion (e.g., a groove) for disposing the sealing material may be provided on the second main surface 4b along the periphery of the first supply opening 16a.

[0053] (Sealing Material on the Second Main Surface 4b Side: Periphery of the First Discharge Opening 20a) Referring to Figure 8, an annular (elliptical) sealing material (not shown) may be arranged on the second main surface 4b of the cell frame 4 along the periphery of the first discharge opening 20a of the first discharge path 14a. This prevents the first electrode liquid (including the produced gas) in the first discharge path 14a from mixing with the second electrode liquid (including the produced gas) in the second discharge path 14b and / or the second electrode chamber 40b. The sealing material has a shape that surrounds the first discharge opening 20a, passes between the second discharge-side support recess 30b (including the joint portion 36b) and the first discharge opening 20a, and passes between the first discharge opening 20a and the second annular protrusion 34b. The second main surface 4b may be provided with a sealant placement portion (for example, a groove) for placing a sealant along the periphery of the first discharge opening 20a.

[0054] (Sealing Material on the Second Main Surface 4b Side: Periphery of the Accommodating Opening 10) Although not shown, a sealing material equivalent to the above-described sealing material 60 may also be disposed on the second main surface 4b of the cell frame 4. This prevents the second electrode liquid (including the generated gas) passing through the second supply path 12b, the second electrode chamber 40b, and the second discharge path 14b from mixing with the first electrode liquid (including the generated gas) passing through the first supply opening 16a and the first discharge opening 20a. The sealing material passes radially outward from the accommodating opening 10, the second supply-side support recess 26b, the second supply opening 16b, the second discharge-side support recess 30b (including the joint 36b), and the second discharge opening 20b. The sealing material also passes radially inward from the second annular protrusion 34b, the first supply opening 16a, and the first discharge opening 20a. The second main surface 4 b may be provided with a sealant placement portion (for example, a groove) along the receiving opening 10 for placing a sealant.

[0055] (Supply Side Cover Plate 6 of Cell 2) As shown in FIG. 1, the supply side cover plate 6 includes a first supply side cover plate 6a covering the first supply recess 18a and a second supply side cover plate 6b covering the second supply recess 18b.

[0056] (First Supply Side Cover Plate 6a) In this embodiment, the first supply side cover plate 6a is formed in an arc shape corresponding to the size of the first supply recess 18a and the first supply side support recess 26a. The material of the first supply side cover plate 6a may be an insulating material such as resin, or a conductive material such as metal. If the first supply side cover plate 6a is formed from a metal material, the surface of the first supply side cover plate 6a may be subjected to a surface treatment such as nickel plating. The first supply side cover plate 6a is supported by the first supply side support recess 26a and the first supply side support protrusions 28a and is attached to the cell frame 4. The first supply side cover plate 6a may be attached to the cell frame 4 by welding or by adhesive tape.

[0057] 9, the outer surface of the first supply-side cover plate 6a is flush with the first main surface 4a of the cell frame 4. In other words, when the inner surface of the first supply-side cover plate 6a is supported by the first supply-side support recess 26a and the first supply-side support protrusion 28a, the outer surface of the first supply-side cover plate 6a is located in the same plane as the surface of the portion of the first main surface 4a of the cell frame 4 where the first supply recess 18a, the first supply-side support recess 26a, the first discharge recess 22a, the first discharge-side support recess 30a, and the first annular protrusion 34a are not formed.

[0058] (Second Supply Side Cover Plate 6b) Like the first supply side cover plate 6a, the second supply side cover plate 6b of this embodiment is formed in an arc shape corresponding to the size of the second supply recess 18b and the second supply side support recess 26b. The material of the second supply side cover plate 6b may be an insulating material such as resin, or a conductive material such as metal. If the second supply side cover plate 6b is formed from a metal material, the surface of the second supply side cover plate 6b may be subjected to a surface treatment such as nickel plating. The second supply side cover plate 6b is supported by the second supply side support recess 26b and the second supply side support protrusion 28b and attached to the cell frame 4. The second supply side cover plate 6b may be attached to the cell frame 4 by welding or by adhesive tape.

[0059] 9, the outer surface of the second supply-side cover plate 6b is flush with the second main surface 4b of the cell frame 4. That is, when the inner surface of the second supply-side cover plate 6b is supported by the second supply-side support recess 26b and the second supply-side support protrusion 28b, the outer surface of the second supply-side cover plate 6b is located in the same plane as the surface of the portion of the second main surface 4b of the cell frame 4 where the second supply recess 18b, the second supply-side support recess 26b, the second discharge recess 22b, the second discharge-side support recess 30b, and the second annular protrusion 34b are not formed.

[0060] (Discharge side cover plate 8 of cell 2) As shown in Figure 1, the discharge side cover plate 8 includes a first discharge side cover plate 8a covering the first discharge recess 22a and a second discharge side cover plate 8b covering the second discharge recess 22b.

[0061] (First Discharge Side Cover Plate 8a) In this embodiment, the first discharge side cover plate 8a is formed in an arc shape corresponding to the size of the first discharge recess 22a and the first discharge side support recess 30a. The material of the first discharge side cover plate 8a may be an insulating material such as resin, or a conductive material such as metal. If the first discharge side cover plate 8a is formed from a metal material, the surface of the first discharge side cover plate 8a may be subjected to a surface treatment such as nickel plating. The first discharge side cover plate 8a is supported by the first discharge side support recess 30a and the first discharge side support protrusion 32a and attached to the cell frame 4. The first discharge side cover plate 8a may be attached to the cell frame 4 by welding or by adhesive tape.

[0062] In this embodiment, the first discharge side cover plate 8a has a joint portion 38a extending in a direction away from the accommodation opening 10 (in this embodiment, radially outward from the cell frame 4). A plurality of joint portions 38a (four in this embodiment) are provided at intervals around the circumferential direction of the cell frame 4. The joint portion 38a of the first discharge side cover plate 8a can be joined by welding to the joint portion 36a of the first discharge side support recess 30a of the cell frame 4. The welding location is preferably at the position of the joint portion 38a and the joint portion 36a furthest from the first electrode chamber 40a (for example, the radially outermost position when the accommodation opening 10 is circular), and on the first main surface 4a of the cell frame 4. This prevents the first electrode liquid from coming into contact with the welded portion between the first discharge side cover plate 8a and the cell frame 4. As a result, when the first discharge side cover plate 8a and the cell frame 4 are formed from a metal material and their surfaces are plated, the components contained in the plating on the first discharge side cover plate 8a and the cell frame 4 are prevented from being eluted by the first electrode solution, which would reduce the electrolytic performance.

[0063] 10 , the outer surface of the first discharge-side cover plate 8a is flush with the first main surface 4a of the cell frame 4. That is, when the inner surface of the first discharge-side cover plate 8a is supported by the first discharge-side support recess 30a and the first discharge-side support protrusion 32a, the outer surface of the first discharge-side cover plate 8a is located in the same plane as the surface of the portion of the first main surface 4a of the cell frame 4 where the first supply recess 18a, the first supply-side support recess 26a, the first discharge recess 22a, the first discharge-side support recess 30a, and the first annular protrusion 34a are not formed.

[0064] (Second Discharge Side Cover Plate 8b) Like the first discharge side cover plate 8a, the second discharge side cover plate 8b of this embodiment is formed in an arc shape corresponding to the size of the second discharge recess 22b and the second discharge side support recess 30b. The material of the second discharge side cover plate 8b may be an insulating material such as resin, or a conductive material such as metal. If the second discharge side cover plate 8b is formed from a metal material, the surface of the second discharge side cover plate 8b may be subjected to a surface treatment such as nickel plating. The second discharge side cover plate 8b is supported by the second discharge side support recess 30b and the second discharge side support protrusion 32b and attached to the cell frame 4. The second discharge side cover plate 8b may be attached to the cell frame 4 by welding or by adhesive tape.

[0065] In this embodiment, the second discharge side cover plate 8b has a joint portion 38b extending in a direction away from the accommodation opening 10 (in this embodiment, radially outward from the cell frame 4). A plurality of joint portions 38b (four in this embodiment) are provided at intervals around the circumferential direction of the cell frame 4. The joint portion 38b of the second discharge side cover plate 8b can be joined by welding to the joint portion 36b of the second discharge side support recess 30b of the cell frame 4. The welding location is preferably at the position of the joint portion 38b and the joint portion 36b farthest from the second electrode chamber 40b (for example, the outermost radial position when the accommodation opening 10 is circular), and on the second main surface 4b of the cell frame 4. This prevents the second electrode liquid from coming into contact with the welded portion between the second discharge side cover plate 8b and the cell frame 4. As a result, when the second discharge side cover plate 8b and the cell frame 4 are formed from a metal material and their surfaces are plated, the components contained in the plating on the second discharge side cover plate 8b and the cell frame 4 are prevented from being eluted by the second electrode liquid, which would cause a decrease in electrolytic performance.

[0066] 10 , the outer surface of the second discharge-side cover plate 8b is flush with the second main surface 4b of the cell frame 4. That is, when the inner surface of the second discharge-side cover plate 8b is supported by the second discharge-side support recess 30b and the second discharge-side support protrusion 32b, the outer surface of the second discharge-side cover plate 8b is located in the same plane as the surface of the portion of the second main surface 4b of the cell frame 4 where the second supply recess 18b, the second supply-side support recess 26b, the second discharge recess 22b, the second discharge-side support recess 30b, and the second annular protrusion 34b are not formed.

[0067] (Partition Wall 42 of Cell 2) Referring to FIGS. 11 , 15 , and 16 , a partition wall 42 is fixed to the housing opening 10 of the cell frame 4, separating the first electrode chamber 40a and the second electrode chamber 40b. As shown in FIGS. 15 and 16 , the partition wall 42 is sheet-like and has a first main surface 42a and a second main surface 42b opposite the first main surface 42a. The partition wall 42 has a plurality of first protrusions 44a protruding toward the first main surface 42a and a plurality of second protrusions 44b protruding toward the second main surface 42b. The first and second protrusions 44a, 44b may be formed by embossing or rib welding. The partition wall 42 may be made of a conductive material such as metal, and the surface of the partition wall 42 may be subjected to a surface treatment such as nickel plating. The outer peripheral shape of the partition wall 42 is the same as the shape of the housing opening 10. In this embodiment, since the accommodation opening 10 is circular as described above, the outer peripheral shape of the partition wall 42 is also circular. The diameter of the partition wall 42 in this embodiment is substantially the same as the diameter of the accommodation opening 10.

[0068] 12 and 13 , in this embodiment, a first current collector 46a, a first electrode 48a, and a membrane 50 are arranged on the first main surface 42a side of the partition wall 42 in this order from the side closest to the first main surface 42a. Furthermore, a second current collector 46b, a cushion material 52, and a second electrode 48b are arranged on the second main surface 42b side of the partition wall 42 in this order from the side closest to the second main surface 42b.

[0069] (First and second current collectors 46a, 46b of cell 2) The first and second current collectors 46a, 46b are formed from perforated plates such as expanded metal or punched metal. The first and second current collectors 46a, 46b may be made of a conductive material such as metal (e.g., nickel, titanium, steel, stainless steel, etc.), and the surfaces of the first and second current collectors 46a, 46b may be subjected to a surface treatment such as nickel plating. The shapes of the first and second current collectors 46a, 46b are the same as the shape of the partition wall 42. In this embodiment, since the partition wall 42 is circular as described above, the first and second current collectors 46a, 46b are also circular. In this embodiment, the diameters of the first and second current collectors 46a, 46b are substantially the same as the diameter of the partition wall 42. The first current collector 46a is joined by welding to the tops of the first protrusions 44a on the first main surface 42a of the partition wall 42, and the second current collector 46b is joined by welding to the tops of the second protrusions 44b on the second main surface 42b of the partition wall 42.

[0070] (First and Second Electrodes 48a, 48b of Cell 2) The first and second electrodes 48a, 48b are formed from perforated plates such as expanded metal or punched metal, or plain woven wire mesh, but are not limited thereto and any widely known electrolysis electrodes can be used. The first and second electrodes 48a, 48b may be made of a conductive material such as metal (e.g., nickel, titanium, steel, stainless steel, etc.), and the surfaces of the first and second electrodes 48a, 48b may be subjected to a surface treatment such as nickel plating. Furthermore, the first and second electrodes 48a, 48b may be appropriately provided with a known water electrolysis catalyst, such as nickel oxide or a noble metal oxide. The shapes of the first and second electrodes 48a, 48b are the same as the shapes of the partition wall 42 and the first and second current collectors 46a, 46b. In this embodiment, since the partition wall 42 and the like are circular as described above, the first and second electrodes 48a, 48b are also circular. In this embodiment, the diameters of the first and second electrodes 48a, 48b are larger than the diameters of the first and second current collectors 46a, 46b. The first electrode 48a serves as either an anode or a cathode, and the second electrode 48b serves as the other of the anode and cathode. Furthermore, if the first current collector 46a also serves as the first electrode, the first electrode 48a may not be provided. Similarly, if the second current collector 46b also serves as the second electrode, the second electrode 48b may not be provided. Furthermore, if the first current collector 46a also serves as the first electrode and the second current collector 46b also serves as the second electrode, both the first and second electrodes 48a, 48b may not be provided.

[0071] (Membrane 50 of Cell 2) In the case of electrolysis of an alkali metal hydroxide aqueous solution, the membrane 50 is configured as an ion-permeable membrane (for example, a diaphragm or an ion exchange membrane), and in the case of electrolysis of an alkali metal chloride aqueous solution, it is configured as an ion exchange membrane. The shape of the membrane 50 is the same as the shapes of the partition wall 42 and the first and second current collectors 46a, 46b. In this embodiment, since the partition wall 42 and the like are circular as described above, the membrane 50 is also circular. The diameter of the membrane 50 in this embodiment is larger than the diameters of the first and second electrodes 48a, 48b.

[0072] (Cushion material 52 of cell 2) The cushion material 52 is an elastic mat with woven wires. The material of the cushion material 52 may be a conductive material such as metal, and the surface of the cushion material 52 may be subjected to a surface treatment such as nickel plating. The shape of the cushion material 52 is the same as the shapes of the partition walls 42 and the first and second current collectors 46a, 46b. In this embodiment, since the partition walls 42 and the like are circular as described above, the cushion material 52 is also circular. The diameter of the cushion material 52 in this embodiment is smaller than the diameters of the first and second current collectors 46a, 46b. When the multiple cells 2 are sandwiched by a press device, the cushion material 52 presses the first and second electrodes 48a, 48b against the membrane 50 to tightly adhere them.

[0073] (Gasket 54 of Cell 2) As shown in Figures 13 and 14, the cell 2 includes a gasket 54 for preventing leakage of the first and second electrode solutions and the generated gas from the first and second electrode chambers 40a, 40b when multiple cells 2 are sandwiched by a press device. The material of the gasket 54 may be an appropriate known material, such as an elastomer. The shape of the gasket 54 corresponds to the shape of the cell frame 4. In this embodiment, since the cell frame 4 is annular as described above, the gasket 54 is also annular. The inner diameter of the gasket 54 in this embodiment is smaller than the diameter of the membrane 50. The outer diameter of the gasket 54 is larger than the diameter of the membrane 50 and is substantially the same as the outer diameter of the cell frame 4. Four openings 54a are formed in the gasket 54 at intervals in the circumferential direction. The positions of the four openings 54a correspond to the positions of the first and second supply openings 16a, 16b and the first and second discharge openings 20a, 20b in the cell frame 4. The gasket 54 is attached to the first main surface 4a of the cell frame 4 with an adhesive, double-sided adhesive tape, or the like. As shown in Figures 15 and 16, the gasket 54, together with the first main surface 4a of the cell frame 4, the first supply side cover plate 6a, and the first discharge side cover plate 8a, sandwiches the peripheral edge of the membrane 50.

[0074] As described above, in this embodiment, the outer surfaces of the first supply-side cover plate 6a and the first discharge-side cover plate 8a are located in the same plane as the surface of the portion of the first main surface 4a of the cell frame 4 where the first supply recess 18a, the first supply-side support recess 26a, the first discharge recess 22a, the first discharge-side support recess 30a, and the first annular protrusion 34a are not formed. Therefore, when the gasket 54, together with the first main surface 4a of the cell frame 4, the first supply-side cover plate 6a, and the first discharge-side cover plate 8a, sandwiches the peripheral edge of the membrane 50, damage to the peripheral edge of the membrane 50 is prevented.

[0075] When assembling an internal manifold type electrolytic cell using the cells 2 as described above, a plurality of cells 2 are prepared and aligned in a predetermined direction. At this time, the first main surface 4a (the surface to which the gasket 54 is attached) of the cell frame 4 of adjacent cells 2 faces the second main surface 4b of the cell frame 4. Furthermore, the first supply openings 16a of the cell frames 4 are aligned with each other, and the second supply openings 16b are aligned with each other. Similarly, the first discharge openings 20a of the cell frames 4 are aligned with each other, and the second discharge openings 20b are aligned with each other.

[0076] Next, the aligned cells 2 are sandwiched and pressed between a fixed head (not shown) and a movable head (not shown). Specifically, the fixed head and the movable head are connected by a plurality of tie rods (not shown), and the aligned cells 2 are sandwiched and pressed between the fixed head and the movable head. As a result, the first supply openings 16a of the cells 2 communicate with each other, forming a first supply manifold for supplying the first electrode liquid to the first electrode chamber 40a of each cell 2. Similarly, the second supply openings 16b communicate with each other, forming a second supply manifold for supplying the second electrode liquid to the second electrode chamber 40b of each cell 2. Furthermore, the first discharge openings 20a communicate with each other, forming a first discharge manifold for discharging the first electrode liquid and the produced gas from the first electrode chamber 40a of each cell 2, and the second discharge openings 20b communicate with each other, forming a second discharge manifold for discharging the second electrode liquid and the produced gas from the second electrode chamber 40b of each cell 2.

[0077] When the multiple cells 2 are sandwiched and pressed between the fixed head and the movable head, the first and second electrode chambers 40a, 40b are sealed by the gaskets 54 of each cell 2. In this embodiment, the press includes a first supply-side cover plate 6a covering the first supply recess 18a of the cell frame 4, a second supply-side cover plate 6b covering the second supply recess 18b of the cell frame 4, a first discharge-side cover plate 8a covering the first discharge recess 22a of the cell frame 4, and a second discharge-side cover plate 8b covering the second discharge recess 22b of the cell frame 4. Therefore, when the multiple cells 2 are pressed, the gaskets 54 do not get into the first and second supply recesses 18a, 18b and the first and second discharge recesses 22a, 22b. This prevents the supply path 12 and the discharge path 14 from being blocked by the gaskets 54 and prevents damage to the gaskets 54 caused by the gaskets 54 getting into the recesses of the cell frame 4.

[0078] Furthermore, since the cell frame 4 of this embodiment is formed with the first and second annular protrusions 34a, 34b, the gasket 54 is sandwiched between the first and second annular protrusions 34a, 34b when the cells 2 are pressed together, thereby more effectively sealing the first and second electrode chambers 40a, 40b.

[0079] Although not shown, the movable head and the fixed head are connected to a first supply flow path member communicating with the first supply manifold, a second supply flow path member communicating with the second supply manifold, a first discharge flow path member communicating with the first discharge manifold, and a second discharge flow path member communicating with the second discharge manifold.

[0080] (Electrolysis) When electrolysis is performed in an electrolytic cell equipped with a plurality of cells 2 as described above, first, the first electrode liquid is supplied to the first supply flow path member from a first electrode liquid pump (not shown), and the second electrode liquid is supplied to the second supply flow path member from a second electrode liquid pump (not shown). The pressure inside the electrolytic cell during electrolysis can be set to any pressure value within a range of approximately 10 kPa to 10 MPa. It is more preferable that the pressure inside the electrolytic cell during electrolysis be within a range of 300 kPa to 5 MPa. This is because the electrolytic cell can be made smaller and the electrolysis efficiency can be improved.

[0081] The first electrode solution supplied to the first supply channel member passes through the first supply manifold and is supplied to the first electrode chamber 40a of each cell 2. The second electrode solution supplied to the second supply channel member passes through the second supply manifold and is supplied to the second electrode chamber 40b of each cell 2. After the first electrode solution is supplied to the first electrode chamber 40a and the second electrode solution is supplied to the second electrode chamber 40b, a required voltage is applied to the first and second electrodes 48a, 48b. This generates gas at both the first and second electrodes 48a, 48b. The gas generated at the first electrode 48a, together with the first electrode solution, passes through the first exhaust manifold and the first exhaust channel member and is sent to a first tank (not shown). The gas generated at the second electrode 48b, together with the second electrode solution, passes through the second exhaust manifold and the second exhaust channel member and is sent to a second tank (not shown).

[0082] As described above, in this embodiment, the first gas-liquid separation promoting portion 24a, which is adjacent to and extends along the accommodation opening 10, is provided in the first discharge recess 22a of the cell frame 4, and the second gas-liquid separation promoting portion 24b, which is adjacent to and extends along the accommodation opening 10, is provided in the second discharge recess 22b of the cell frame 4. Therefore, after the electrolysis reaction, the first electrode liquid and the generated gas are quickly separated in the first gas-liquid separation promoting portion 24a, and the second electrode liquid and the generated gas are quickly separated in the second gas-liquid separation promoting portion 24b, without increasing the size of the cell frame 4 or reducing the electrode area. Therefore, the flow of the electrode liquid is uniform in both the first and second electrode chambers 40a, 40b, and excessively large differences in concentration between the electrode liquids are prevented. As a result, the current distribution is uniform, preventing a decrease in electrolysis efficiency.

[0083] Furthermore, in this embodiment, gas-liquid separation is performed in the first and second gas-liquid separation promoting sections 24 a, 24 b, so that the flow from the first electrode chamber 40 a toward the first discharge manifold and the flow from the second electrode chamber 40 b toward the second discharge manifold can be made uniform, thereby reducing pressure fluctuations within the electrolytic cell and suppressing fluctuations in electrolysis voltage and damage to the membrane 50 caused by pressure fluctuations within the electrolytic cell.

[0084] Furthermore, in this embodiment, the accommodation opening 10 of the cell frame 4 and the first and second electrode chambers 40a, 40b are circular, and the first and second gas-liquid separation promotion sections 24a, 24b of the cell frame 4 are arc-shaped. Therefore, compared to a case in which the accommodation opening 10 and the first and second electrode chambers 40a, 40b are rectangular, the first electrode liquid and the produced gas flow more smoothly through the first electrode chamber 40a, the first gas-liquid separation promotion section 24a, and the first discharge manifold in that order, and the second electrode liquid and the produced gas flow more smoothly through the second electrode chamber 40b, the second gas-liquid separation promotion section 24b, and the second discharge manifold in that order, thereby more effectively suppressing the accumulation of the produced gas.

[0085] Note that the present invention is not limited to the above-described embodiment and various modifications are possible. For example, the first and second supply-side support recesses 26a, 26b may have joint portions extending in a direction away from the accommodation opening 10, the first and second supply-side cover plates 6a, 6b may have joined portions extending in a direction away from the accommodation opening 10, the joined portions of the first supply-side cover plate 6a may be joined by welding to the joint portions of the first supply-side support recess 26a, and the joined portions of the second supply-side cover plate 6b may be joined by welding to the joint portions of the second supply-side support recess 26b. This prevents the electrode liquid from coming into contact with the welded portions between the first and second supply-side cover plates 6a, 6b and the cell frame 4. As a result, when the first and second supply side cover plates 6a, 6b and the cell frame 4 are formed from a metal material and their surfaces are plated, components contained in the plating of the first and second supply side cover plates 6a, 6b and the cell frame 4 are prevented from being eluted by the electrode solution, which would cause a decrease in electrolytic performance.

[0086] Alternatively, the supply-side support recess and the discharge-side support recess of the cell frame 4 may be connected, and the supply-side cover plate and the discharge-side cover plate may be formed integrally. That is, as shown in FIG. 17 , a first annular connection support recess 56a may be formed on the first main surface 4a of the cell frame 4, connecting the first supply-side support recess and the first discharge-side support recess, and a second annular connection support recess (not shown) may be formed on the second main surface 4b of the cell frame 4, connecting the second supply-side support recess and the second discharge-side support recess. An annular first cover plate 58a, formed integrally with the first supply-side cover plate and the first discharge-side cover plate, is attached to the first connection support recess 56a. An annular second cover plate 58b, formed integrally with the second supply-side cover plate and the second discharge-side cover plate, is attached to the second connection support recess.

[0087] 2: Cell 4: Cell frame 4a: First main surface of cell frame 4b: Second main surface of cell frame 6: Supply side cover plate 6a: First supply side cover plate 6b: Second supply side cover plate 8: Discharge side cover plate 8a: First discharge side cover plate 8b: Second discharge side cover plate 10: Storage opening 12: Supply channel 12a: First supply channel 12b: Second supply channel 14: Discharge channel 14a: First discharge channel 14b: Second discharge channel 16a: First supply opening 16b: Second supply opening 18a: First supply recess 18b: Second supply recess 20a: First discharge opening 20b: Second discharge opening 22a: First discharge recess 22b: Second discharge recess 24a: First gas-liquid separation promotion section 24b: Second gas-liquid separation promotion section 26a: First supply-side support recess 26b: Second supply-side support recess 28a: First supply-side support protrusion 28b: Second supply-side support protrusion 30a: First discharge-side support recess 30b: Second discharge-side support recess 32a: First discharge-side support protrusion 32b: Second discharge-side support protrusion 36a: Joining portion of first discharge-side support recess 36b: Joining portion of second discharge-side support recess 38a: Joined portion of first discharge-side cover plate 38b: Joined portion of second discharge-side cover plate 40a: First electrode chamber 40b: Second electrode chamber 42: Partition wall 42a: First main surface of partition wall 42b: Second main surface of partition wall 46a: First current collector 46b: Second current collector 48a: First electrode 48b: Second electrode 50: Membrane 52: Cushioning material 54: Gasket

Claims

1. A cell frame for an internal manifold type electrolytic cell, the cell frame having formed therein an accommodation opening capable of accommodating a partition wall that separates an electrode chamber, a supply path for supplying electrode solution to the electrode chamber, and a discharge path for discharging the electrode solution and generated gas from the electrode chamber, the supply path including a supply opening disposed below the accommodation opening and a supply recess communicating with the supply opening and the accommodation opening, the discharge path including a discharge opening disposed above the accommodation opening and a discharge recess communicating with the discharge opening and the accommodation opening, the discharge recess having a gas-liquid separation promoting portion adjacent to the accommodation opening and extending along the accommodation opening.

2. A cell frame for an internal manifold type electrolytic cell as described in claim 1, wherein the length of the gas-liquid separation promoting portion in the direction along the accommodation opening is between 1 / 4 and 1 / 2 of the peripheral length of the accommodation opening.

3. The cell frame for an internal manifold type electrolytic cell according to claim 1, wherein the receiving opening is circular and the gas-liquid separation promoting portion is arc-shaped.

4. The cell frame of an internal manifold type electrolytic cell according to claim 1, wherein the electrode chambers comprise an anode chamber and a cathode chamber, the supply path includes an anode-side supply path for supplying anolyte to the anode chamber and a cathode-side supply path for supplying catholyte to the cathode chamber, the discharge path includes an anode-side discharge path for discharging the anolyte and anode generated gas from the anode chamber and a cathode-side discharge path for discharging the catholyte and cathode generated gas from the cathode chamber, and the gas-liquid separation promoter is provided in at least one of the anode-side discharge path or the cathode-side discharge path.

5. A cell for an internal manifold type electrolytic cell, comprising the cell frame of claim 1, a supply-side cover plate covering the supply recess, and a discharge-side cover plate covering the discharge recess, wherein the cell frame has a supply-side support recess shallower than the supply recess formed adjacent to the supply recess, and a discharge-side support recess shallower than the discharge recess formed adjacent to the discharge recess, the supply-side support recess supports the inner surface of the supply-side cover plate, and the discharge-side support recess supports the inner surface of the discharge-side cover plate, and the outer surface of the supply-side cover plate and the outer surface of the discharge-side cover plate are located on the same plane as the surfaces of the cell frame in those parts where the supply recess, supply-side support recess, discharge recess and discharge-side support recess are not formed.

6. A cell for an internal manifold type electrolytic cell as set forth in claim 5, wherein the supply recess is provided with a plurality of supply side support protrusions spaced apart from one another, which, together with the supply side support recess, support the inner surface of the supply side cover plate; and the discharge recess is provided with a plurality of discharge side support protrusions spaced apart from one another, which, together with the discharge side support recess, support the inner surface of the discharge side cover plate.

7. The internal manifold type electrolytic cell according to claim 5, wherein the supply side cover plate and the discharge side cover plate are joined to the cell frame by welding.

8. A cell for an internal manifold type electrolytic cell according to claim 7, wherein the supply-side support recess has a joining portion extending in a direction away from the accommodation opening, the supply-side cover plate has a joined portion extending in a direction away from the accommodation opening, and the joined portion of the supply-side cover plate is joined to the joining portion of the supply-side support recess by welding.

9. A cell for an internal manifold type electrolytic cell as set forth in claim 7, wherein the discharge side support recess has a joining portion extending in a direction away from the accommodation opening, the discharge side cover plate has a joined portion extending in a direction away from the accommodation opening, and the joined portion of the discharge side cover plate is joined to the joining portion of the discharge side support recess by welding.

10. An internal manifold type electrolytic cell according to claim 5, wherein the supply side support recess and the discharge side support recess are connected, and the supply side cover plate and the discharge side cover plate are integrally formed.

11. A cell for an internal manifold type electrolytic cell according to claim 5, wherein a partition is fixed to the accommodation opening of the cell frame, the partition having a first main surface and a second main surface located opposite to the first main surface, a first current collector, a first electrode and a membrane arranged on the first main surface side of the partition in that order from closest to the first main surface, and a second current collector, a cushion material and a second electrode arranged on the second main surface side of the partition in that order from closest to the second main surface, and a gasket is attached to the cell frame which sandwiches the peripheral edge of the membrane together with the cell frame, the supply side cover plate and the discharge side cover plate.

12. An internal manifold type electrolytic cell in which a plurality of cells according to claim 5 are aligned in a predetermined direction, wherein the cell frame has a first main surface and a second main surface located opposite the first main surface, the first main surface of the cell frame faces the second main surface of the cell frame between adjacent cells, the supply openings of the cell frames communicate with each other to form a supply manifold, and the discharge openings of the cell frames communicate with each other to form a discharge manifold.

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