JP3320834B2 - Bipolar electrolytic cell - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel bipolar electrolytic cell. The electrolytic cell provided by the present invention has an extremely small conductor resistance, allows easy replacement of the anode, and has very little damage to the electrolytic cell in the event of a trouble.

By using the bipolar electrolytic cell, the electrolytic voltage at the time of electrolysis can be reduced, the deteriorated anode can be easily replaced, and the repair of the electrolytic cell at the time of trouble can be extremely simplified.

[0003]

2. Description of the Related Art Various types of electrolyzers for industrially performing electrolysis such as electrolysis of saline are known. It goes without saying that when performing electrolysis industrially, it is important to reduce the electrolysis voltage, and for that purpose, it is desired that the conductor resistance of the electrolyzer be low. Also,
There is a demand for an electrolytic cell structure in which the anode can be easily renewed due to activity deterioration, damage, and the like, and furthermore, even if a trouble occurs, the damage is minimal.

In the present invention, an electrolytic cell used for electrolysis of an aqueous solution of alkali chloride will be described as an example.

A technique for producing chlorine from the anode side and producing caustic soda and hydrogen from the cathode side by electrolyzing saline using a fluorine-containing cation exchange membrane as a membrane is generally known as an ion exchange membrane method using salt electrolysis. being called. It is generally well known that the ion exchange membrane salt electrolysis technique has higher energy efficiency and can produce high-purity caustic soda as compared with the conventional mercury method and diaphragm method.

[0006] In recent years, there has been an increasing demand for energy saving, and there is an increasing need to further improve the energy efficiency of ion exchange membrane method salt electrolysis. That is, techniques for performing salt electrolysis with lower electrolysis voltage and / or higher current efficiency are currently being developed.

[0007] The theoretical decomposition voltage of the saline solution is about 2.2 V, but it is usually operated at a voltage higher than this theoretical decomposition voltage by 1 V or more. This is the overvoltage of the anode and cathode,
It is well known that the voltage is increased by various resistance components such as film resistance, liquid resistance, and conductor resistance. That is,
In order to reduce the electrolysis voltage, reduction of anode overvoltage, reduction of cathode overvoltage, reduction of membrane resistance, reduction of solution resistance, and reduction of conductor resistance of an electrolytic cell are important issues.

At present, an electrode in which a titanium substrate coated with a catalyst having a low chlorine overvoltage characteristic such as ruthenium oxide is put to practical use and is generally used as an anode. Also, various kinds of electrodes having low hydrogen overvoltage characteristics have been devised for the cathode, and the electrodes have been put to practical use. With these technologies, anode overvoltage,
And the cathode overvoltage has been improved to a considerable level. Since the catalytic activity of the anode gradually decreases with electrolysis, it is necessary to renew the electrode catalyst after long-term use. Usually, the renewal of the anode electrocatalyst is made by replacing the anode with a new anode.

On the other hand, as the cation exchange membrane, a fluorinated cation exchange membrane in which a carboxylic acid group and / or a sulfonic acid group is bonded as a fixed ion to a fluororesin matrix is used. The cation exchange membrane reduces the electrolysis voltage,
Improvements have been made to improve current efficiency and durability. As a result, the reduction of the film resistance and the improvement of the current efficiency have been improved to a considerable level.

[0010] Therefore, in recent years, the objectives have been changed to improve the electrolytic method and the electrolytic cell for the purpose of reducing the liquid resistance and the conductor resistance. As a method of reducing the liquid resistance, it has been proposed to carry out electrolysis by bringing the cathode and the anode as close as possible. That is, this is an electrolysis method in which the membrane and the anode, and the cathode and the membrane are adhered to each other. In this case, in order to alleviate a rise in electrolysis voltage due to bubbles generated during electrolysis adhering to the surface of the membrane, a bubble opening treatment for preventing air bubbles from adhering to the anode side surface and / or the cathode side surface of the membrane. Is generally used.

By the way, electrolytic cells used industrially are roughly classified into a monopolar type and a bipolar type. In contrast to the monopolar type electrolytic cell, the bipolar type electrolytic cell is provided for each electrolytic cell. There are many advantages, such as a relatively simple structure because no wiring is required, and a rectifier, busbar, etc. that are compact and inexpensive because a large current is not required. Therefore, the industrial value of reducing the conductor resistance of the bipolar electrolytic cell is very large.

[0012] The conductor resistance is greatly affected by the structure and material of the electrolytic cell. That is, the conductor resistance is determined by the specific resistance of the current path flowing through the electrolytic cell and the material of the electrolytic cell used for the current path. Therefore, the conductor resistance can be reduced by shortening the current path as much as possible and / or by using a material having a low specific resistance for the material adopted for the current path.

However, in the electrolytic cell for alkali chloride electrolysis, nickel or iron-based alloy having relatively small specific resistance can be adopted as the material on the cathode side, but the material on the anode side generally has chlorine gas resistance, but has specific resistance. Is relatively large titanium, or
A titanium-based alloy or the like is used. Moreover, in the conventional bipolar electrolytic cell, a substantially flat titanium partition is used as the anode-side partition, and the partition and the anode are electrically and mechanically joined by a conductive rib made of titanium. Further, as a passage for homogenizing the liquid in the anode chamber and discharging the generated chlorine gas to the outside of the electrolytic cell, a space between the anode and the anode-side partition is usually 30 to 5 mm.
A distance of 0 mm is required.

That is, in the conventional bipolar electrolytic cell, the voltage increases due to the so-called conductor resistance while the current flows through the conductive rib on the anode side having a large specific resistance. Therefore, a bipolar electrolytic cell capable of reducing the conductor resistance particularly on the anode side has been desired.

In order to respond to the above request, the applicant of the present invention disclosed in Japanese Patent Application Laid-Open No. 58-71382 in which the negative / anode chamber was formed of a corrosion-resistant metal sheet for the purpose of reducing the conductor resistance of the electrolytic cell. Furthermore, an electrolytic cell was proposed in which the thin plate was made into a corrugated plate having irregularities.

FIG. 4 and FIG. 5 on page 5 of the publication show cross-sectional views of an electrolytic cell showing an example of a preferred embodiment. The electric connection between the cathode chamber and the anode chamber is performed by pressure bonding. It is formed, and the voltage loss due to the connector can be eliminated, and the voltage loss due to the conductive ribs can also be eliminated because the anode is directly joined to the projection of the anode-side partition. According to the applicant's invention, the so-called conductor resistance is extremely reduced.

However, when the present inventors carried out the electrolysis of alkali chloride using the electrolytic cell, they found the following serious disadvantages.

That is, when replacing the anode whose electrode catalyst activity has been reduced due to long-term use, the anode-side partition is easily damaged when the anode is removed, and the installation of the anode also requires much labor. Also, after prolonged alkali chloride electrolysis, pinholes are formed in the ion exchange membrane, and the surrounding anode and anode-side partition walls may be significantly corroded. Thus, the electrolytic cell in which the anode side is severely damaged is repaired. The only way to do this is to replace all the anode partition walls of the electrolytic cell.
Repairs require significant labor and materials.

[0019]

SUMMARY OF THE INVENTION According to the present invention, in order to meet the above demand, the anode having a low conductor resistance on the anode side and having a reduced catalytic activity can be easily replaced, and troubles occur even during operation. It is another object of the present invention to provide a bipolar electrolytic cell that can be easily and economically repaired.

[0020]

According to the present invention, there is provided a bipolar electrolytic cell having a projection in which an anode-side partition is projected to the anode side, and the projection and the anode are connected via a conductive member. A bipolar electrolyzer characterized by being electrically joined together. Alternatively, the present invention relates to a bipolar electrolytic cell having a concave portion in which an anode-side partition protrudes toward a cathode.

By using the bipolar electrolytic cell provided by the present invention, electrolysis can be carried out at a low voltage because the conductor resistance on the anode side is small, the anode can be easily renewed, and if the pin is attached to the membrane temporarily, Even if a hole is generated, the damage to the electrolytic cell is extremely small, and the repair of the damage can be performed very simply and inexpensively.

Hereinafter, the structure of the electrolytic cell provided by the present invention will be described with reference to the drawings. However, these drawings are described as an example of a preferred embodiment of the present invention, and it is a matter of course that the present invention is not limited by these drawings. In addition, since the bipolar electrolytic cell is well known in the art, the characteristics of the present invention will be described in detail by taking a bipolar electrolytic cell for electrolysis of an aqueous solution of alkali chloride as an example. Although the supply and discharge nozzles for the electrolytic solution, the cathode, and the like are omitted, the same materials and structures as those used in the conventional bipolar electrolytic cell may be used by appropriately applying them.

FIGS. 1 and 2 show an example of the structure of a bipolar electrolytic cell preferably used in the present invention. FIGS. 3 and 4 illustrate the relationship between the anode-side partition, the cathode-side partition, and the anode.

In the drawing, (1) denotes an anode-side partition, which is usually formed of a flat plate made of titanium or a titanium-based alloy.
(2) denotes a cathode-side partition, which is usually formed of a flat plate such as stainless steel or nickel. It is essential that the anode-side partition wall (1) has a projection (4 + 4 ') projecting toward the anode (6) (where 4 indicates a protruding surface and 4' indicates an inclined surface). Further, the anode-side partition (1) may have a concave portion (5) protruding toward the cathode (not shown).

In order to further reduce the conductor resistance and increase the mechanical strength, a conductive member (3) is provided between the anode-side partition (1) and the cathode-side partition (2). May be. In addition, it is essential that the anode-side partition (1) and the anode (6) be attached via another conductive member (3 '). It is preferable that titanium or a titanium-based alloy is used as a material for forming the partition wall (1) at least on the surface on the anode side. This can be made of, for example, a titanium thin plate, or can be made of titanium and a clad of a good conductive material other than titanium. Examples of the good conductive material other than titanium include copper, a copper-based alloy, iron, and an iron-based alloy. However, when the base material is made of titanium and a clad material other than titanium, it goes without saying that titanium is used facing the anode side.

Further, the vertical height of the projection (4 + 4 ') or the vertical difference between the projection surface (4) and the depression (5) is preferably 10 mm or more and 70 mm or less. Since the flat portion or the concave portion (5) of the anode-side partition (1) functions as a passage for the electrolyte and the gas, the voltage reduction effect is reduced when the thickness is less than 10 mm. On the other hand, when it exceeds 70 mm, the width of the electrolytic cell increases, the conductor resistance increases, the installation area increases, and the material cost per electrolytic cell increases, which is not preferable.

The projections (4 + 4 ') may or may not have the same shape. In addition, the convex portions (4 + 4 ′) can be provided in parallel with each other and substantially in the vertical direction. However, as another preferred embodiment, the angle is preferably within 45 degrees with respect to the vertical direction. You can also tilt at an angle. However, if it has an angle larger than 45 degrees, the air bubbles will stay in the projections and adversely affect the electrolytic characteristics.

Further, it is not necessary for the unevenness to be continuous in the vertical direction. Rather, it is preferable that the unevenness is divided into a plurality in the vertical direction in order to more sufficiently mix the internal electrolyte solution. This can be achieved, for example, by a shape as shown in FIG.

On the other hand, the shape of the protruding surface (4) is not limited at all. For example, any shape such as a rectangle, a parallelogram, a polygon, a circle, and an ellipse is used as appropriate.

FIGS. 5 and 6 show a conventional bipolar electrolytic cell and its relationship with the anode-side partition, the cathode-side partition and the anode.

A conductive rib (7) is mounted on the anode-side partition (1), and an anode (6) is mounted on the conductive rib (7). As described above, the conductive rib (7) is usually made of titanium or a titanium-based alloy, and when electricity flows through the conductive rib, the voltage increases due to the conductor resistance. Therefore, in order to reduce the electrolysis voltage, it is desired that the conductive ribs be as short as possible.However, since a passage for discharging the electrolytic solution and chlorine gas out of the electrolytic cell is provided on the back surface of the anode, Usually 30 to 50 mm between the back and anode side partition
Need a width that allows for the gap between

Usually, the anode-side partition (1) is made of nickel,
It is electrically connected at least partially with a cathode-side partition (2) such as iron. The cathode-side partition (2) is joined to a cathode (not shown) by a conductive rib (not shown).

In the present invention, the ratio of the total area of the protruding surface (4) to the effective electrolysis area is 5%.
% Or more and not more than 60%.
If it is less than 5%, the conductor resistance increases and the effect of the present invention decreases. It is preferably at least 15%. on the other hand,
If it exceeds 60%, the supply state of the electrolyte deteriorates, and
Since the generated gas stays, the electrolysis voltage increases, and / or
Alternatively, the current efficiency is lowered, and in some cases, the film is damaged.

On the other hand, the shape of the cathode-side partition (2) is not particularly limited as long as it is manufactured using a material conventionally used as a material. For example, it may be a flat plate or may have irregularities like the anode-side partition. When the cathode-side partition has irregularities, the cathode-side projection is defined similarly to the anode-side partition, but these shapes may be the same as or different from the anode-side partition.

It is preferable to use nickel or a nickel-based alloy as the surface material on the cathode side since corrosion during electrolysis is particularly suppressed. This is, for example,
The partition walls can be composed of nickel or a nickel-based alloy alone, or the nickel layer of a material formed by plating or spraying nickel or a nickel-based alloy layer on iron or an iron-based alloy can be turned to the cathode side. But it is possible.

It is essential that the anode-side partition (1) and the cathode-side partition (2) are electrically connected at least partially. At this time, it is preferable that at least one portion of the electrical connection be electrically connected between the convex inner surface of the anode-side partition and the cathode-side partition.

FIG. 3 shows, as an example of a cross section taken along line AA ′ of FIG. 1, a partition wall of an electrolytic cell comprising a cathode partition wall (2) which is substantially a flat plate and an anode partition wall (1) having a convex portion. The example in the case of comprising is shown.

As shown in FIG. 3, the inner surface of the convex portion of the anode-side partition is electrically connected to the inner surface of the anode-side partition via a conductive member (3) substantially vertically bonded to the inner surface of the cathode-side partition. Here, it is desired that the conductive member (3) has a small electric resistance. Preferably, copper, nickel, iron, or an alloy containing at least one of these is used.

The anode-side partition and the cathode-side partition may be joined at other portions. Rather, if the other portions are joined, the mechanical strength of the partition wall is improved. For example, the mechanical strength is improved by directly joining the flat part of the anode-side partition and the cathode-side partition.

It is essential that the protruding surface (4) of the anode-side partition and the anode (6) are electrically connected via a conductive member (3 '). If the protruding surface (4) of the anode-side partition and the anode (6) are directly joined without the interposition of the conductive member (3 '), the effect of the present invention will not be exhibited at all.

FIG. 4 is an example of a cross section taken along line BB ′ of FIG. 2. FIG. 4 shows an example in which the cathode-side partition (2) has the same shape as the anode-side partition (1).

In this case, it is preferable that at least the projecting surface (4) of the anode-side partition and the cathode-side partition are electrically connected. The bonding at this time may be via a conductive member (3), or if the protruding surface (4) on the anode side and the back surface of the cathode-side partition (2) are directly bonded as shown in FIG. It is preferable because it is possible. It is also a preferable method to electrically bond the entire surface.

For example, the electrical connection between the anode-side partition and the cathode-side partition can be carried out by spot welding or the like, or the cathode-side partition and the anode-side partition can be joined by using the explosion method. . Further, it is also possible to suitably use the present invention to deform a composite member in which the anode-side partition and the cathode-side partition are joined by pressure bonding into a desired shape. It is also possible to deform a plate-like titanium and nickel plate material by press molding or the like.

Furthermore, it is essential that the protruding surface (4) of the anode-side partition and the anode (6) are electrically connected via a conductive member (3 '). If the protruding surface (4) of the anode-side partition and the anode (6) are directly joined without the interposition of the conductive member (3 '), the effect of the present invention will not be exhibited at all.

For example, FIGS. 7 and 8, which are cross-sectional views of a conventional electrolytic cell having a convex portion, are illustrated as an example of a conventional electrolytic cell in which the anode-side partition has irregularities. In these cases, the projecting surface (4) of the anode-side partition and the anode (6) are directly joined, and the effect of the present invention is not exhibited at all, such as that the anode-side partition is easily damaged.

In the electrolytic cell having the cross-sectional structure illustrated in FIGS. 7 and 8, if the anode-side partition and the anode are electrically connected via the conductive member (3 '), the present invention It is needless to say that this is one of the preferred embodiments of the electrolytic cell.

As the material of the conductive member (3 '), a material having conductivity and sufficient durability under electrolysis in the anode chamber can be used as appropriate. Preferably, the material of at least the surface is titanium or a titanium-based alloy. The conductive member (3 ') can be made entirely of titanium or a titanium-based alloy, and can also contain a highly conductive material such as copper. For example, a square bar or round bar made of titanium, a square bar having a surface of titanium and having copper therein, a clad material of a round bar, or the like can be suitably used.

Note that one conductive member (3 ') may be used for one projecting surface (4), or a plurality of conductive members (3') may be used. Further, the ratio of the projected area occupied by the conductive member (3 ′) to the protruding surface (4) is preferably 70% or less.
If it is more than 70%, the supply of the electrolytic solution in this portion is deteriorated, which not only causes an increase in voltage and / or a decrease in current efficiency, but also adversely affects the film. However, the ratio is preferably 5% or more. If it is less than 5%, the conductive member (3 ') becomes thin, and the conductor resistance increases.

When the anode-side partition and the anode are joined via the conductive member (3 '), the distance between the protruding surface (4) of the anode-side partition and the back surface of the anode is preferably 2 mm or more, more preferably 3 mm. That is all. When the distance between the protruding surface (4) of the anode-side partition (1) and the anode back surface is less than 2 mm, the anode-side partition (1) is easily damaged, and the effect of the present invention cannot be sufficiently obtained. On the other hand, if the distance is 2 mm or more, the effect of the present invention can be exerted at any value. However, if the distance is too large, the installation area of the electrolytic cell itself increases, and the conductor resistance further increases. Is usually 10m
m or less, preferably 5 mm or less.

As the anode, any existing anodes for alkali chloride electrolysis can be used. For example, an anode obtained by forming an electrode catalyst layer having a low chlorine overvoltage characteristic such as ruthenium oxide on a titanium substrate is used. Although the shape is not particularly limited, it is preferable to use a perforated plate-shaped electrode because generated chlorine gas escapes to the back surface of the electrode and is then discharged outside the cell. Electrodes having such a shape are widely known as punched metal, expanded metal, or mesh electrodes.

On the other hand, for joining the cathode-side partition and the cathode, any conventionally known method can be applied. For example,
When the cathode-side partition is formed substantially as a plane as shown in FIG. 3, the cathode-side partition is supported by using a conductive rib so as to be separated from the cathode by 10 to 50 mm. As the conductive rib, all the conventionally used ones can be applied.

When the cathode-side partition is made of a member having irregularities as shown in FIG. 4, the recess (5) of the anode-side partition and the cathode can be directly electrically connected. If necessary, it is also possible to electrically connect via a conductive member similarly to the anode.

Further, in the electrolytic cell of the present invention, the electrolysis voltage can be extremely reduced by installing an active cathode having a low hydrogen overvoltage characteristic. For example, an electrode obtained by electroplating an active nickel layer on an electrode of iron, an iron-based alloy, nickel, or a nickel-based alloy is applicable. A method for producing such an active cathode is disclosed in, for example, Japanese Patent Application Laid-Open No. 58-6983. In the case where such an active cathode is provided, it is preferable that the cathode is joined to the partition wall, and then the active cathode is plated on the cathode and the entire cathode chamber.

A method for carrying out electrolysis of an aqueous alkali chloride solution using the bipolar electrolytic cell described above will be described. Various methods are already known for the electrolysis method of the aqueous alkali chloride solution, and these methods may be applied as appropriate in the present invention.

That is, a plurality of the bipolar electrolytic cells are placed in series, a diaphragm is provided between the anode and the cathode, and an anode chamber and a cathode chamber are formed. The number of tanks at this time is not particularly limited, but is usually 5
It is about 30 tanks. It is preferable to use a fluorine-containing cation exchange membrane for the membrane, but it is also possible to use a membrane method such as asbestos.

The anode and the membrane and the cathode and the membrane can be arranged at a certain interval. However, it is preferable to arrange them in contact with each other because the solution resistance is reduced. In this case, it is desirable that the cation exchange membrane to be used has been subjected to a bubble release treatment on the anode side surface and / or the cathode side surface. Such cation exchange membranes are widely and generally known.

The anode compartment is supplied with a purified alkali chloride solution, and the cathode compartment is supplied with pure water and / or a caustic solution. The liquid may be supplied to each of the chambers independently, but is usually supplied in parallel.

At this time, the supply concentration is not particularly limited. Usually, the concentration of the alkali chloride solution is set in the range of 230 g / liter to the saturation concentration, and the concentration of the caustic is set to 32% by weight or less.

An electric current is passed in series from the endmost anode to the endmost cathode, and chlorine and a diluted alkali chloride solution are discharged from the anode chamber by electrolysis, and hydrogen and caustic are discharged from the cathode chamber. Is done. All discharges may be performed independently, but usually, the anode system and the cathode system are each performed in parallel. Chlorine and hydrogen each become products after a purification step and the like. In addition, the diluted alkali chloride solution is usually partially recycled, and the remainder is processed and, if necessary, reused. Caustic alkali is usually partially recycled and the remainder is a product after a concentration step and the like.

The concentration of the diluted alkali chloride and the concentration of the caustic discharged are not particularly limited, and the concentration of the diluted alkali chloride is usually in the range of 230 to 170 g / liter, and the concentration of the caustic is in the range of 20 to 50% by weight. Is set to

The electrolytic current density is not particularly limited.
７7 KA / m ² .

The electrolysis temperature is not particularly limited.
It is about 100 ° C.

As described above, by using the bipolar electrolytic cell of the present invention for electrolysis of a conventionally known alkali chloride solution, the anode having a low conductor resistance on the anode side, a reduced electrolysis voltage, and a reduced catalytic activity. Can be easily replaced, and even if a trouble occurs during operation, repair can be performed simply and economically.

It is needless to say that the bipolar electrolytic cell of the present invention is applicable not only to electrolysis of an alkali chloride solution but also to other industrial electrolysis fields.

[0065]

The effects obtained by using the novel bipolar electrolytic cell provided by the present invention as compared with conventionally known electrolytic cells can be summarized into the following three.

That is, first, the electrolytic cell provided by the present invention can reduce the electrolytic voltage because the conductor resistance is small. This corresponds to the electrolytic cells shown in FIGS. 1 and 2 provided by the present invention,
It is clear from a comparison with FIG. 5 which is a typical example of an electrolytic cell generally used in the related art. In the electrolytic cell of FIG. 5, the electrical connection between the anode-side partition and the anode was made by conductive ribs made of titanium. In this case, since electricity is supplied to the anode through the conductive rib made of titanium having a large resistance, a large voltage drop occurs in this portion. For this reason, the ratio of conductor resistance loss to the electrolytic voltage is large.

However, in the electrolytic cell of the present invention, the electrical connection between the anode side partition and the anode is only a very short distance conductive member (3 '). Therefore, voltage loss due to conductor resistance between the anode-side partition and the anode is extremely reduced.
Therefore, the electrolysis voltage decreases. In addition, since the anode-side partition and the cathode-side partition are electrically connected with copper, nickel, or the like, the conductor resistance between them can be neglected.

Second, it is possible to easily renew the anode which has been used for a long period of time and has a reduced catalytic activity. That is, in the electrolytic cell of the present invention, since the anode-side partition (1) and the anode (6) are joined via the conductive member, there is no danger of damaging the partition in the step of removing the anode, and , Can be easily removed and attached.

Third, comparing the electrolytic cell provided by the present invention with the conventional electrolytic cell shown in FIGS. 7 and 8 as a specific example of JP-A-58-71382, the electrolytic cell of the present invention Since the projecting surface (4) of the anode-side partition and the anode (6) are joined via the conductive member (3 '), the area where the projecting surface (4) of the anode-side partition closes the hole of the anode. Is small. Therefore, the electrolyte is sufficiently supplied between the anode and the film as in the other portions, there is no retention of chlorine gas, and there is no concern that the film is particularly adversely affected at the portion. Moreover, even if a pinhole occurs in the membrane, the electrolytic cell of the present invention does not directly contact the anode-side partition (1) and the diaphragm, and the anode-side partition (1) is separated from the diaphragm by 2 mm or more. Therefore, the anode-side partition does not undergo any corrosion, and only the anode or the anode and the conductive member (3 ') are corroded. Because of this,
At the time of repair, it is only necessary to replace the corroded anode or the anode and the conductive member (3 '), and the repair cost is significantly reduced, and the repair can be performed extremely easily.

It is surprising that the provision of the conductive member (3 ') on the protruding surface (4) of the anode-side partition significantly reduces corrosion in the event of a trouble. It can be said that the provided electrolytic cell is extremely superior in performance to the conventional electrolytic cell.

The design concept and the effect of the electrolytic cell structure of the present invention are as follows. The effect of caustic corrosion leaking into the anode chamber due to pinholes in the membrane is about 1 mm toward the anode-side partition from the back of the anode. The achievement of only the range was achieved by the present inventors having found for the first time.

[Brief description of the drawings]

FIG. 1 is a plan view showing one example of an electrolytic cell of the present invention.

FIG. 2 is a plan view showing one example of the electrolytic cell of the present invention.

FIG. 3 is a cross-sectional view taken along the line AA ′ of FIG. 1, showing an example of the electrolytic cell of the present invention.

FIG. 4 is a cross-sectional view taken along the line BB ′ of FIG. 2, showing an example of the electrolytic cell of the present invention.

FIG. 5 is a plan view showing an example of a bipolar electrolyzer conventionally used generally.

FIG. 6 is a cross-sectional view taken along the line CC ′ of FIG. 5, showing an example of a conventional electrolytic cell.

FIG. 7 shows an example of a cross-sectional view of a conventional electrolytic cell having a convex portion.

FIG. 8 shows an example of a conventional electrolytic cell. In the drawings, 1 is an anode-side partition, 2 is a cathode-side partition, 3
Is a conductive member for joining the cathode side partition and the anode side partition, 3 ′
Is a conductive member for joining the anode side partition and the anode, (4 + 4
') Denotes an anode convex portion, 4 denotes a projecting surface of an anode side convex portion, 4' denotes an inclined surface of an anode side convex portion, 5 denotes a cathode side concave portion, 6 denotes an anode, and 7 denotes a conductive rib. However, the drawings are only for showing the features of the present invention, and liquid supply / drainage nozzles, cathodes and the like are omitted.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C25B 1/00-15/08

Claims (2)

(57) [Claims] In a bipolar electrolytic cell, the anode-side partition has a projection protruding toward the anode, and the projection and the anode are electrically connected via a conductive member. A bipolar electrolyzer comprising: 2. The bipolar electrolytic cell according to claim 1, further comprising a concave portion in which an anode-side partition protrudes toward a cathode.