Method for manufacturing an electrolytic cell unit and electrolytic cell unit

Abstract

Provided is a method for manufacturing an electrolytic cell unit that can improve welding quality. This method for manufacturing an electrolytic cell unit comprises: a step for arranging first and second ribs 14, 30, first and second partition walls 12, 28, and a clad plate 8 in a positional relationship in the order of the first rib 14, which is formed from a first material, the first partition wall 12, which is formed from the first material, the clad plate 8, which comprises a layer 8a of the first material and a layer 8b of a second material with an electrical resistance lower than that of the first material, the second partition wall 28, which is formed from the second material, and the second rib 30, which is formed from the second material; and a step for joining the first and second ribs 14, 30, the first and second partition walls 12, 28, and the clad plate 8 by resistance welding. A first protrusion 64 is formed in the first rib 14, a second protrusion 66 is formed in the second rib 30, and the size of the first protrusion 64 is different from the size of the second protrusion 66.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an electrolytic cell unit and an electrolytic cell unit.

Background Art

[0002] Patent Document 1 below discloses a method for manufacturing an electrolytic cell unit, which is a component of a bipolar electrolytic cell for electrolyzing an aqueous solution of an alkali metal chloride to produce chlorine and an alkali metal hydroxide.

[0003] In this manufacturing method, first, a titanium partition material is disposed on the surface of a first titanium partition (first pan) having a flange portion formed at its periphery, and at least a part of the partition material is welded to the flange portion of the first partition to form a gas-liquid separation chamber. Similarly, a nickel partition material is disposed on the surface of a second nickel partition (second pan) having a flange portion formed at its periphery, and at least a part of the partition material is welded to the flange portion of the second partition to form a gas-liquid separation chamber.

[0004] Next, a plurality of first titanium ribs are disposed on the surface of the first partition. Also, a plurality of clad plates having a two-layer structure of a titanium layer and a nickel layer are disposed at positions corresponding to each first rib on the back side of the first partition. Further, the back of the second partition is overlapped with the back of the first partition, and a plurality of second nickel ribs are disposed on the surface of the second partition at positions corresponding to the clad plates.

[0005] Next, a step of simultaneously performing resistance welding between each first rib and the surface of the first partition, resistance welding between the back of the first partition and the titanium layer of the clad plate, resistance welding between the nickel layer of the clad plate and the back of the second partition, and resistance welding between the surface of the second partition and each second rib is carried out. Further, a step of loading a frame material into the space formed between the flange portion of the first partition and the flange portion of the second partition is carried out.

[0006] Furthermore, Patent Document 1 states that, according to the above manufacturing method, by positioning the first rib and the clad plate opposite each other across the first partition wall, and positioning the second rib and the clad plate opposite each other across the second partition wall, resistance welding between the first rib, the first partition wall, and the clad plate can be achieved simultaneously, and resistance welding between the second rib, the second partition wall, and the clad plate can be reduced. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2002-155388 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, there is room for improvement in welding quality in conventional electrolytic cell unit manufacturing methods.

[0009] Since nickel has a lower electrical resistance than titanium, the amount of heat generated during resistance welding of titanium components (first partition wall, first rib, and titanium layer of cladding plate) is greater than the amount of heat generated during resistance welding of nickel components (second partition wall, second rib, and nickel layer of cladding plate).

[0010] Therefore, it is difficult to adjust the welding current to ensure sufficient joint strength between titanium components and between nickel components. If the welding current is too low, the components will not melt sufficiently, resulting in insufficient joint strength. On the other hand, if the welding current is too high, there is a high possibility of "splatter," where molten metal explodes and scatters. If "splatter" occurs, it leads to a decrease in weld strength and damage to the base material. In addition, since the thickness of the base material decreases due to the scattering of molten base material, the risk of electrolytic cells that generate corrosive gases such as chlorine being damaged during operation increases. Furthermore, if the welding quality is poor, the structural resistance value of the electrolytic cell during operation increases, which leads to a deterioration in power consumption per unit.

[0011] The object of the present invention is to provide a method for manufacturing an electrolytic cell unit that can improve welding quality, and an electrolytic cell unit that improves power consumption per unit. [Means for solving the problem]

[0012] According to the present invention, the following method for manufacturing an electrolytic cell unit is provided that solves the above problems. In other words, "A method for manufacturing an electrolytic cell unit, Arrangement step of arranging the first rib, the first partition wall, the clad plate, the second partition wall, and the second rib in the following order: first rib formed from the first material, first partition wall formed from the first material, clad plate having a layer of the first material and a layer of the second material having lower electrical resistance than the first material, second partition wall formed from the second material, and second rib formed from the second material. The process includes a joining step of joining the first rib, the first partition wall, the cladding plate, the second partition wall, and the second rib by resistance welding, A first projection is formed on the joint portion of the first rib that is joined to the first partition wall, and a second projection is formed on the joint portion of the second rib that is joined to the second partition wall. The size of the first projection and the size of the second projection are different, or the number of the first projections and the number of the second projections are different. the law of nature, The diameter of the first projection is greater than the diameter of the second projection. The diameter of the first projection is between 1.05 and 3.7 times the diameter of the second projection. A method for manufacturing an electrolytic cell unit is provided.

[0013] before It is desirable that the amount of protrusion of the first projection is smaller than the amount of protrusion of the second projection. It is also preferable that the number of first projections is greater than the number of second projections.

[0014] It is convenient that the thickness of the first rib is greater than the thickness of the second rib. It is preferable that the depth of the first rib is greater than the depth of the second rib. It is suitable that the first material is titanium. The second material may be nickel.

[0015] before It is suitable that the radial distance from the center of the first protrusion to the center of the second protrusion is within 15 mm. In the joining step, it is convenient to perform resistance welding at 350 or more and 550 or less locations per 1 m2 of the effective electrode area.

[0016] According to the present invention, there is provided an electrolytic cell unit that solves the above problems. That is, there is provided an electrolytic cell unit manufactured by the manufacturing method of the electrolytic cell unit as described above, wherein the area of the weld mark of the first protrusion is 1.15 times or more and 13.7 times or less the area of the weld mark of the second protrusion.

[0017] Also, there is provided an electrolytic cell unit manufactured by the manufacturing method of the electrolytic cell unit as described above, wherein the radial distance from the center of the weld mark of the first protrusion to the center of the weld mark of the second protrusion is within 15 mm.

[0018] Furthermore, there is provided an electrolytic cell unit manufactured by the manufacturing method of the electrolytic cell unit as described above, wherein the locations of the resistance welding are 350 or more and 550 or less per 1 m 2 of the effective electrode area.

Advantages of the Invention

[0019] In the manufacturing method of the present invention, the size of the first protrusion formed on the first rib made of the first material is different from the size of the second protrusion formed on the second rib made of the second material, or the number of the first protrusions is different from the number of the second protrusions Furthermore, the diameter of the first projection is greater than the diameter of the second projection, and the diameter of the first projection is between 1.05 and 3.7 times the diameter of the second projection.Therefore, the difference between the amount of heat generated during welding of the member made of the first material and the amount of heat generated during welding of the member made of the second material having a lower electrical resistance than the first material becomes smaller. As a result, adjustment of the welding current becomes easier, and while ensuring sufficient bonding strength between the members made of the first material and between the members made of the second material, it is possible to reduce "scattering" in which the melted base material ruptures and scatters. Therefore, according to the manufacturing method of the present invention, variations in welding quality are unlikely to occur, and the welding quality can be improved. Further, according to the electrolytic cell unit of the present invention, since the structural resistance value can be kept low, the power unit is improved.

Brief Description of Drawings

[0020] [Figure 1] Plan view of an electrolytic cell unit manufactured according to the method of the present invention. [Figure 2] Cross-sectional view taken along line A-A in FIG. 1. [Figure 3] Partially enlarged cross-sectional view taken along line B-B in FIG. 1. [Figure 4] Cross-sectional view showing a state in which an array process is performed. [Figure 5] Cross-sectional view showing a state in which an array process is performed when the number of protrusions of the first rib is larger than the number of protrusions of the second rib. [Figure 6] Cross-sectional view showing a state in which a joining process is performed.

Embodiments for Carrying Out the Invention

[0021] Hereinafter, embodiments of a method for manufacturing an electrolytic cell unit of the present invention will be described with reference to the drawings.

[0022] (Electrolytic cell unit 2) Referring to Figures 1 and 2, the electrolytic cell unit 2 that can be manufactured by the method of the present invention comprises an anode chamber member 4 formed from a first material, a cathode chamber member 6 (see Figure 2) formed from a second material having lower electrical resistance than the first material, and a cladding plate 8 (see Figure 2) having a layer 8a of the first material and a layer 8b of the second material. For example, titanium (Ti) can be used as the first material. Nickel (Ni) may be used as the second material.

[0023] (Anode chamber component 4) As shown in Figures 2 and 3, the anode chamber member 4 made of a first material (for example, titanium) includes an anode plate 10, a first partition wall 12 spaced apart from the anode plate 10, and a plurality of first ribs 14 positioned between the anode plate 10 and the first partition wall 12.

[0024] (Anode plate 10) The rectangular anode plate 10 has numerous openings, although these are not shown in the diagram. The shape of the openings is arbitrary and can be, for example, rhombus, flat fan, or slit. The numerous openings can be arranged in a staggered pattern.

[0025] (1st bulkhead 12) The first partition wall 12 is positioned at a distance from the anode plate 10 in the depth direction (direction D) indicated by arrow D in Figure 2. As shown in Figure 2, the lower end portion of the first partition wall 12 is bent toward the lower end of the anode plate 10, thereby forming a bottom plate 18 that defines the lower end of the anode chamber 16. Although not shown, both sides of the first partition wall 12 in the width direction (direction indicated by arrow W in Figure 1) are also bent toward the anode plate 10, forming side walls that define the widthwise ends of the anode chamber 16.

[0026] (1st Rib 14) As shown in Figure 1, multiple first ribs 14 are provided at intervals in the width direction. Each first rib 14 extends along the vertical direction (V direction) indicated by the arrow V in Figure 1. Referring to Figures 2 and 3, the first rib 14 has a main portion 20 that extends from the anode plate 10 toward the first partition wall 12, and a plurality of connecting pieces 22 that protrude in the width direction from the end of the main portion 20 on the first partition wall 12 side.

[0027] The end of the main section 20 on the anode plate 10 side is joined to the anode plate 10 by welding. On the other hand, each joining piece 22 is joined to the surface 12a of the first partition wall 12 by welding. As can be understood by referring to Figure 2, the end of the main section 20 on the first partition wall 12 side is provided with a plurality of notches 24 spaced apart in the vertical direction. The notches 24 are located between adjacent joining pieces 22. The plurality of notches 24 ensure the flow of liquid and gas in the width direction within the anode chamber 16.

[0028] (Cathode chamber member 6) As shown in Figures 2 and 3, the cathode chamber member 6 made of a second material (for example, nickel) includes a current collector 26, a second partition wall 28 spaced apart from the current collector 26, and a plurality of second ribs 30 positioned between the current collector 26 and the second partition wall 28.

[0029] (Current collector 26) The rectangular current collector 26, like the anode plate 10, is provided with numerous openings (not shown). The shape of the openings is arbitrary; for example, a diamond shape, a flat fan shape, or a slit shape can be used. The arrangement of the numerous openings can be staggered.

[0030] Although not shown in the diagram, when an electrolytic cell is assembled by arranging numerous electrolytic cell units 2 in the depth direction and pressing them from both sides in the depth direction, a cathode plate is attached to the outer surface of the current collector 26 (the right side in Figure 2) via a metal cushioning material.

[0031] (Second bulkhead 28) The second partition wall 28 is positioned at a distance from the current collector 26 in the depth direction (direction D). As shown in Figure 2, the lower end portion of the second partition wall 28 is bent toward the lower end of the current collector 26, similar to the first partition wall 12, forming a bottom plate 34 that defines the lower end of the cathode chamber 32. Although not shown, both sides of the second partition wall 28 in the width direction (direction W) are also bent toward the current collector 26, forming side walls that define the widthwise ends of the cathode chamber 32.

[0032] (2nd rib 30) The second ribs 30, like the first ribs 14, are provided in multiples at intervals in the width direction and extend along the vertical direction (V direction). As shown in Figure 3, the multiple second ribs 30 are positioned in locations corresponding to the positions of the multiple first ribs 14. The second rib 30 has a main portion 36 that extends from the current collector 26 toward the second bulkhead 28, and multiple connecting pieces 38 that protrude in the width direction from the end of the main portion 36 on the second bulkhead 28 side.

[0033] The end of the main section 36 on the current collector 26 side is joined to the current collector 26 by welding. On the other hand, each joining piece 38 is joined to the surface 28a of the second partition wall 28 by welding. As can be understood by referring to Figure 2, the end of the main section 36 on the second partition wall 28 side is provided with a number of notches 40 spaced apart in the vertical direction. The notches 40 are located between adjacent joining pieces 38. The number of notches 40 ensures the flow of liquid and gas in the width direction within the cathode chamber 32.

[0034] Regarding the relationship between the dimensions of the first rib 14 and the dimensions of the second rib 30, as shown in Figure 3, it is advantageous for the thickness T1 of the first rib 14 to be greater than the thickness T2 of the second rib 30 (T1>T2). Also, it is preferable for the depth D1 of the main part 20 of the first rib 14 to be greater than the depth D2 of the main part 36 of the second rib 30 (D1>D2).

[0035] (Clad plate 8) Referring to Figure 3 along with Figure 2, the cladding plates 8 are provided in multiple quantities at intervals in the width direction and extend along the vertical direction. The cladding plates 8 are located between the back surface 12b of the first partition wall 12 and the back surface 28b of the second partition wall 28, and are positioned to correspond to the joining piece 22 of the first rib 14 and the joining piece 38 of the second rib 30.

[0036] The clad plate 8 in the illustrated embodiment is a two-layer plate material in which a layer 8a of a first material (for example, a titanium layer) and a layer 8b of a second material (for example, a nickel layer) having lower electrical resistance than the first material are joined by explosive compression, or the layer 8a of the first material and the layer 8b of the second material are joined by rolling. The layer 8a of the first material is joined by welding to the back surface 12b of the first partition wall 12 made of the first material. On the other hand, the layer 8b of the second material is joined by welding to the back surface 28b of the second partition wall 28 made of the second material.

[0037] (Supply nozzles 44, 46) As shown in Figure 2, a hollow, rectangular lower frame 42 is provided at the bottom of the electrolytic cell unit 2. The lower frame 42 can be made of a suitable metal material such as stainless steel. The lower frame 42 is provided with two through holes (not shown) that penetrate vertically. A supply nozzle 44 for supplying raw materials to the anode chamber 16 is attached to one of the through holes, and a supply nozzle 46 (see Figure 1) for supplying raw materials to the cathode chamber 32 is attached to the other through hole. Although not shown, side frames are provided at both ends in the width direction of the electrolytic cell unit 2.

[0038] (Gas-liquid separation chambers 48, 50) As shown in Figure 2, the upper part of the electrolytic cell unit 2 is provided with a gas-liquid separation chamber 48 on the anode side and a gas-liquid separation chamber 50 on the cathode side.

[0039] (Gas-liquid separation chamber 48 on the anode side) The anode-side gas-liquid separation chamber 48 has an L-shaped partition member 52 made of the first material and a rectangular top plate 54 made of the first material. Multiple openings (not shown) are formed in the bottom portion 52a of the partition member 52 at intervals in the width direction. These multiple openings allow liquid and gas to flow vertically between the anode chamber 16 and the gas-liquid separation chamber 48.

[0040] As shown in Figure 1, a discharge nozzle 56 for discharging the gas and liquid from the gas-liquid separation chamber 48 is attached to the widthwise end of the gas-liquid separation chamber 48. The discharge nozzle 56 is formed from the first material.

[0041] (Cathode side gas-liquid separation chamber 50) The gas-liquid separation chamber 50 on the cathode side has an L-shaped partition member 58 made of the second material and a rectangular top plate 60 made of the second material. Multiple openings (not shown) are formed in the bottom portion 58a of the partition member 58 at intervals in the width direction. The multiple openings allow liquid and gas to flow vertically between the cathode chamber 32 and the gas-liquid separation chamber 50.

[0042] A discharge nozzle 62 for discharging gas and liquid from the gas-liquid separation chamber 50 is attached to the end of the gas-liquid separation chamber 50 in the width direction (the end opposite to the end where the anode-side discharge nozzle 56 is provided). The discharge nozzle 62 is made of the second material.

[0043] (Manufacturing method for electrolytic cell unit 2) Next, the manufacturing method of the electrolytic cell unit 2 as described above will be explained.

[0044] First, a partition material 52, a top plate 54, and a discharge nozzle 56 are welded to the upper part of the first partition wall 12 to form the anode-side gas-liquid separation chamber 48. Similarly, a partition material 58, a top plate 60, and a discharge nozzle 62 are welded to the upper part of the second partition wall 28 to form the cathode-side gas-liquid separation chamber 50. The order in which the gas-liquid separation chambers 48 and 50 are formed does not matter.

[0045] (Arrangement process) Once the gas-liquid separation chambers 48 and 50 are formed, an arrangement process is carried out in which the first rib 14, first partition wall 12, cladding plate 8, second partition wall 28, and second rib 30 are arranged in the following order: first rib 14, first partition wall 12, cladding plate 8, second partition wall 28, and second rib 30.

[0046] In this process, for example, as shown in Figure 4, the components can be arranged in the following order from top to bottom: the first rib 14 from the top, the first partition wall 12 from the top, the cladding plate 8 from the top, the second partition wall 28 from the top, and the second rib 30 from the top.

[0047] Alternatively, the arrangement may be reversed from the positional relationship shown in Figure 4, with the first rib 14 in the first position from the bottom, the first partition wall 12 in the second position from the bottom, the cladding plate 8 in the third position from the bottom, the second partition wall 28 in the fourth position from the bottom, and the second rib 30 in the fifth position from the bottom.

[0048] During the arrangement process, the first layer 8a of the clad plate 8 is oriented toward the back surface 12b of the first partition wall 12 made of the first material, and the second layer 8b of the clad plate 8 is oriented toward the back surface 28b of the second partition wall 28 made of the second material. In addition, the widthwise positions of the joining pieces 22 of the first rib 14, the clad plate 8 and the joining pieces 38 of the second rib 30 are aligned, and adjacent members are brought into contact with each other.

[0049] The chronological order in which the first and second ribs 14 and 30, the first and second partitions 12 and 28, and the cladding plates 8 are arranged is arbitrary. The number of first ribs 14, second ribs 30, and cladding plates 8 arranged can be one or more. However, when arranging multiple first ribs 14, second ribs 30, and cladding plates 8, the number of first ribs 14, second ribs 30, and cladding plates 8 must be the same.

[0050] (1st and 2nd protrusions 64, 66) As can be understood by referring to Figure 4, a first projection 64 is formed on the joining piece 22 of the first rib 14 (the joining portion that is joined to the surface 12a of the first partition wall 12). Also, a second projection 66 is formed on the joining piece 38 of the second rib 30 (the joining portion that is joined to the surface 28a of the second partition wall 28). The shapes of the first and second projections 64 and 66 can be any shape, such as circular or rectangular.

[0051] In the illustrated embodiment, it is important that the size of the first projection 64 and the size of the second projection 66 are different, or that the number of first projections 64 and the number of second projections 66 are different.

[0052] One example of the difference in size between the first projection 64 and the second projection 66 is when the diameter d1 of the first projection 64 is larger than the diameter d2 of the second projection 66 (d1 > d2). Another example is when the projection amount S1 of the first projection 64 is smaller than the projection amount S2 of the second projection 66 (S1 <S2)ことである。

[0053] When the diameter d1 of the first projection 64 is larger than the diameter d2 of the second projection 66, it is desirable that the diameter of the first projection 64 be 1.05 times or more and 3.7 times or less than the diameter of the second projection 66, more preferably 1.05 times or more and 3.0 times or less, and particularly preferably 1.15 times or more and 2.5 times or less. As a result, in the electrolytic cell unit manufactured through the joining process described later, the area A1 of the weld marks of the first projection 64 (see Figure 6) will be 1.15 times or more and 13.7 times or less than the area A2 of the weld marks of the second projection 66 (see Figure 6), preferably 1.15 times or more and 6.8 times or less, and particularly preferably 1.15 times or more and 2.5 times or less, thereby keeping the structural resistance value of the welded part low.

[0054] Generally, the structural resistance of a structure where members are not welded together but merely in contact is greater than that of a continuous structure where members are welded together. Therefore, if the area A1 of the weld mark of the first projection 64 is less than 1.15 times the area A2 of the weld mark of the second projection 66, the welding area is small, and the structural resistance of the welded portions of the first rib 14, first partition wall 12, cladding plate 8, second partition wall 28, and second rib 30 tends to increase, resulting in an increase in the overall structural resistance of the electrolytic cell unit.

[0055] On the other hand, if the area A1 of the weld mark of the first projection 64 exceeds 13.7 times the area A2 of the weld mark of the second projection 66, the thermal energy required for welding increases. This leads to a deterioration in the required electrode flatness accuracy due to thermal distortion caused by welding, resulting in an increase in structural resistance. Furthermore, the increased energy required for welding leads to a deterioration in welding quality.

[0056] The difference between the number of first protrusions 64 and the number of second protrusions 66 means, for example, as shown in Figure 5, that the number of first protrusions 64 is greater than the number of second protrusions 66. Here, the number of first protrusions 64 refers to the number of protrusions formed on one connecting piece 22 of the first rib 14, and the number of second protrusions 66 refers to the number of protrusions formed on one connecting piece 38 of the second rib 30.

[0057] In the example shown in Figure 5, two first protrusions 64 are provided on one connecting piece 22 of the first rib 14, and one second protrusion 66 is provided on one connecting piece 38 of the second rib 30. However, the number of each protrusion is not limited to the number shown in Figure 5 and can be set arbitrarily.

[0058] To summarize the relationship between the size and number of the first and second protrusions 64 and 66, it is sufficient that at least one of the following conditions 1 to 3 be satisfied. 1. The diameter d1 of the first projection 64 is greater than the diameter d2 of the second projection 66 (d1 > d2). 2. The amount of protrusion S1 of the first projection 64 is smaller than the amount of protrusion S2 of the second projection 66 (S1 <S2)。 3. The quantity of the first projection 64 is greater than the quantity of the second projection 66.

[0059] Note that two of the above conditions 1 to 3 may be satisfied, or all of the above conditions 1 to 3 may be satisfied. Figure 4 shows an example where conditions 1 and 2 are satisfied, and Figure 5 shows an example where all of the above conditions 1 to 3 are satisfied.

[0060] In the arrangement process, it is preferable to keep the radial distance (distance in the width direction W or depth direction D, not the vertical direction V) from the center C1 of the first projection 64 to the center C2 of the second projection within 15 mm. As a result, in the electrolytic cell unit manufactured through the joining process described later, the radial distance from the center of the weld mark of the first projection 64 to the center of the weld mark of the second projection 66 is within 15 mm, and reactive current (reactive current flowing in a direction perpendicular to the thickness direction of the first and second partitions 12 and 28) flowing along the first and second partitions 12 and 28 in the current path from the anode plate 10 to the cathode plate (not shown) can be suppressed. Therefore, the electrolytic cell unit has a low resistance value between the anode plate 10 and the cathode plate.

[0061] (Joining process) After the arrangement process is carried out, a joining process is performed in which the first rib 14, the first partition wall 12, the cladding plate 8, the second partition wall 28, and the second rib 30 are joined by resistance welding. Spot welding may be used for the resistance welding in the joining process.

[0062] In the joining process, one electrode of a resistance welding machine (not shown) is brought into contact with the joining piece 22 of the first rib 14, and the other electrode of the resistance welding machine is brought into contact with the joining piece 38 of the second rib 30. This clamps the first and second ribs 14 and 30, the first and second partition walls 12 and 28, and the cladding plate 8 between the pair of electrodes of the resistance welding machine, and applies a predetermined pressure to each of the above-mentioned components.

[0063] Then, when an electric current is passed through the electrodes, Joule heat is generated due to electrical resistance, causing the first projection 64 to melt and collapse, and as shown in Figure 6, the joining piece 22 of the first rib 14 and the surface 12a of the first partition wall 12 are joined together. At the same time, the second projection 66 melts and collapses, and the joining piece 38 of the second rib 30 and the surface 28a of the second partition wall 28 are joined together.

[0064] Furthermore, due to Joule heating caused by electrical resistance during energization, the back surface 12b of the first partition wall 12 and the layer 8a of the first material of the cladding plate 8 are joined together, and the back surface 28b of the second partition wall 28 and the layer 8b of the second material of the cladding plate 8 are joined together.

[0065] In such bonding processes, the effective electrode area is 1 m². 2 It is advantageous to apply resistance welding to locations between 350 and 550. If the number of resistance welds is less than 350, it will lead to an increase in structural resistance. On the other hand, if the number of resistance welds exceeds 550, the effect of suppressing the increase in structural resistance due to the increase in resistance welds is low, and it will actually lead to a decrease in productivity. Note that the effective electrode area is the area of ​​the electrode plate that substantially contributes to electrolysis out of the total area of ​​the electrode plate.

[0066] As described above, in the illustrated embodiment, the size of the first projection 64 formed on the joining piece 22 made of the first material is different from the size of the second projection 66 formed on the joining piece 38 made of the second material, or the number of first projections 64 is different from the number of second projections 66. As a result, the difference between the amount of heat generated in the member made of the first material (first partition wall 12, first rib 14, and layer 8a of the first material of the cladding plate 8) and the amount of heat generated in the member made of the second material, which has lower electrical resistance than the first material (second partition wall 28, second rib 30, and layer 8b of the second material of the cladding plate 8) becomes smaller.

[0067] This makes it easier to adjust the welding current, ensuring sufficient joint strength between members made of the first material and between members made of the second material, while reducing "splash" caused by the molten base material bursting and scattering. Therefore, according to the illustrated embodiment, variations in welding quality are less likely to occur, and welding quality can be improved.

[0068] After the joining process is carried out in this manner, the lower frame 42 is positioned below the first and second partition walls 12 and 28, and the lower parts of the first and second partition walls 12 and 28 and the lower frame 42 are joined by welding. Next, the anode-side supply nozzle 44 and the cathode-side supply nozzle 46 are joined to the lower frame 42 by welding.

[0069] Furthermore, side frames are positioned at both ends in the width direction of the first and second bulkheads 12 and 28, and the side frames are joined to each of the width directions of the first and second bulkheads 12 and 28 by welding. Then, the anode plate 10 is joined to the end of the main portion 20 of the first rib 14 by welding, and the current collector 26 is joined to the end of the main portion 36 of the second rib 30 by welding.

[0070] As described above, according to the illustrated embodiment, the difference between the amount of heat generated during welding of the member made of the first material and the amount of heat generated during welding of the member made of the second material is small, and internal scattering can be reduced, so variations in welding quality are less likely to occur and welding quality can be improved.

[0071] Incidentally, since the electrical resistance of the first material is greater than that of the second material, as shown in the illustrated embodiment, when the thickness T1 of the first rib 14 is greater than the thickness T2 of the second rib 30 (T1>T2), the difference between the amount of heat generated in the component made of the first material and the amount of heat generated in the component made of the second material can be further reduced. The same applies when the depth D1 of the first rib 14 is greater than the depth D2 of the second rib 30 (D1>D2).

[0072] Furthermore, if the first material is titanium and the second material is nickel, then if the thickness T1 of the first rib 14 is greater than the thickness T2 of the second rib 30 made of the second material, or if the depth D1 of the first rib 14 is greater than the depth D2 of the second rib 30 made of the second material, then it is possible to reduce the amount of nickel components while suppressing the increase in the structural resistance of the electrolytic cell unit 2, thereby reducing the cost of the electrolytic cell unit 2. [Explanation of symbols]

[0073] 2: Electrolytic cell unit 8: Clad plate 8a: Layer of the first material 8b: Layer of the second material 12:First bulkhead 14: First Rib 28:Second bulkhead 30: Second Rib 64: 1st protrusion 66:Second protrusion

Claims

1. A method for manufacturing an electrolytic cell unit, Arrangement step of arranging the first rib, the first partition, the clad plate, the second partition, and the second rib in the following order: first rib formed from the first material, first partition wall formed from the first material, clad plate having a layer of the first material and a layer of the second material having lower electrical resistance than the first material, second partition wall formed from the second material, and second rib formed from the second material. The process includes a joining step of joining the first rib, the first partition wall, the cladding plate, the second partition wall, and the second rib by resistance welding, A first projection is formed on the joint portion of the first rib that is joined to the first partition wall, and a second projection is formed on the joint portion of the second rib that is joined to the second partition wall. The size of the first projection and the size of the second projection are different, or the number of the first projections and the number of the second projections are different. The diameter of the first projection is greater than the diameter of the second projection. A method for manufacturing an electrolytic cell unit, wherein the diameter of the first projection is 1.05 times or more and 3.7 times or less the diameter of the second projection.

2. The method for manufacturing an electrolytic cell unit according to claim 1, wherein the amount of protrusion of the first projection is smaller than the amount of protrusion of the second projection.

3. The method for manufacturing an electrolytic cell unit according to claim 1 or 2, wherein the number of the first protrusions is greater than the number of the second protrusions.

4. The method for manufacturing an electrolytic cell unit according to any one of claims 1 to 3, wherein the thickness of the first rib is greater than the thickness of the second rib.

5. The method for manufacturing an electrolytic cell unit according to any one of claims 1 to 4, wherein the depth of the first rib is greater than the depth of the second rib.

6. The method for manufacturing an electrolytic cell unit according to any one of claims 1 to 5, wherein the first material is titanium.

7. The method for manufacturing an electrolytic cell unit according to any one of claims 1 to 6, wherein the second material is nickel.

8. A method for manufacturing an electrolytic cell unit according to any one of claims 1 to 7, wherein the radial distance from the center of the first projection to the center of the second projection is 15 mm or less.

9. The method for manufacturing an electrolytic cell unit according to any one of claims 1 to 8, wherein in the joining step, resistance welding is performed at 350 to 550 locations per 1 m² of effective electrode area.

10. An electrolytic cell unit manufactured by the method for manufacturing an electrolytic cell unit described in Claim 1, wherein the area of ​​the weld marks of the first projection is 1.15 times or more and 13.7 times or less the area of ​​the weld marks of the second projection.

11. An electrolytic cell unit manufactured by the method for manufacturing an electrolytic cell unit according to any one of claims 1 to 9, An electrolytic cell unit in which the radial distance from the center of the weld mark of the first projection to the center of the weld mark of the second projection is 15 mm or less.

12. An electrolytic cell unit manufactured by the method for manufacturing an electrolytic cell unit according to any one of claims 1 to 9, The electrolytic cell unit has resistance welding points of 350 to 550 per 1 m² of effective electrode area.

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