JPH062958B2 - Vertical electrolytic cell - Google Patents

Description

The present invention relates to a bipolar electrode type vertical electrolytic cell which avoids current concentration at electrode terminals.

2. Description of the Related Art As an electrolytic cell for electrolyzing seawater, there is one conventionally called a vertical structure bipolar electrode system as shown in FIG. In FIG. 1, (a) shows a vertical sectional structure of a vertical electrolytic cell, (b) is an AA sectional view thereof, and (c) is a B-section thereof.
It is B sectional drawing, (d) is an enlarged view of C part of (a). In this vertical electrolytic cell, a plurality of bipolar electrodes 2 are provided inside the electrolytic cell body 1 so as to face each other in parallel via a partition plate 3 and in multiple stages. The current supplied via the bus bars 6 and 7 connected to the upper terminal plate 5 of the lower terminal plate 4 of the
It is configured to electrolyze seawater flowing through the electrode 2 and flowing inside the electrolytic cell body 1. The seawater is introduced into the inside of the electrolytic cell body 1 through an inlet nozzle 8 provided in the lower portion of the electrolytic cell body 1, flows between the bipolar electrodes 2, and then is provided in the upper portion of the electrolytic cell body 1. It is designed to be discharged from the outlet nozzle 9.

However, in the vertical electrolytic cell having such a configuration, when focusing on the pair of bipolar electrodes 2 between the partition plates 3,
The effective length (effective length) of the electrode 2 used as the (+) pole and the electrode 2 used as the (−) pole are equal. Therefore, a phenomenon of current concentration at the end of the electrode 2 acting as the (-) electrode occurs, and by-products such as magnesium hydroxide produced by the decomposition of seawater are easily attached (precipitated) to the current concentration portion. The problem arose. Moreover, such deposits (precipitates) cause problems such as blocking of the seawater flow path between the bipolar electrodes 2 and wear of the anode material.

The present invention has been made in view of such circumstances, and an object of the present invention is to prevent the local current concentration of the electrode and eliminate the adverse effects of the conventional vertical electrolysis having a highly practical structure. It is to provide a tank.

The vertical electrolyzer according to the present invention includes an outer tube pair having an inlet nozzle and an outlet nozzle, an electrode support box made of an insulating tube provided inside the outer tube, and an electrode support box disposed in the electrode support box. And a plurality of bipolar electrodes supported and installed. Each of the bipolar electrodes is a plate-shaped electrode in which the length of the cathode part is set longer than the length of the anode part, and the first and second electrode groups are formed by horizontally arranging the two electrodes. Are arranged such that the two-pole electrodes of each group are relatively adjacent to each other by a 1/2 pitch in the vertical direction and are alternately adjacent to each other at regular intervals. Is positioned so as to face the central portion of the cathode portion of the other adjacent two-pole electrode.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a vertical sectional view showing a schematic configuration of a vertical electrolytic cell according to an embodiment, and FIG. 3 is a view showing a DD sectional structure thereof.

The electrolytic cell 11 is composed of a cylindrical outer cylinder 11a, and an upper lid 11b and a lower lid 11c that are closed at the upper and lower surfaces thereof to form an outer cylindrical body having a predetermined pressure resistance. An inlet nozzle 12 for inflowing seawater is provided at a lower position of the outer cylinder 11a, and an outlet nozzle 13 for discharging the seawater is provided at an upper position thereof. Seawater combined with electrolysis is made to flow through the electrolytic layer 11 through these nozzles 12, 13.

Thus, in the electrolytic cell 11, there is provided an electrode support box 14 having a rectangular tube structure made of an electrical insulator such as plastic. The electrode support box 14 is constructed by framing first and second support frames 14a and 14b in a quadrangular shape as shown in FIG. 3, for example. A plurality of bipolar electrodes 15 are provided inside the electrode support box 14.
Are arranged and fixed in parallel with a predetermined gap T in multiple stages. Specifically, the plurality of bipolar electrodes 15 are superposed in parallel with each other via a spacer 16 having a thickness T, and the insulation bolt
It is supported in a skewered shape at 17 and fixed between the support frames 14b.

In this way, the bipolar electrode 15 provided in the electrode support box 14
For example, as shown in FIG. 4, one electrode plate is divided into two,
One of them has a cathode part 15a and the other has an anode part 15b. The bipolar electrode 15 has an anode part 15 formed by plating platinum on one region of an electrode plate made of titanium, for example, or by coating a platinum group metal or its oxide.
b and the other area is the cathode portion 15a. The length La of the cathode portion 15a is set to the length L of the anode portion 15b.
It is configured to be set longer than b.

As shown in FIG. 5, a plurality of bipolar electrodes 15 having such a structure are arranged in the electrode support box 14 with the cathode portion 15a and the anode portion 15b facing each other between the adjacent electrodes 15. .

Therefore, the uppermost electrode is electrically connected to the electrode terminal plate 18, and is connected to an external current lead (bus bar) via the electrode terminal plate 18. Similarly, the lowermost electrode is electrically connected to the electrode terminal plate 19, and is connected to an external current lead (bus bar) via the electric terminal plate 19. Then, the current i supplied through these electrode terminal plates 18 and 19 is made to flow in the electrolytic cell 11 from the uppermost electrode in series to the lowermost electrode in series as shown in FIG. Has become.

Thus, according to the vertical electrolytic cell having such a structure,
The electric current flowing between the polar electrodes 15 electrolyzes the seawater flowing between the electrodes 15. By electrolysis of this seawater, Cl ₂ ions are generated on the side of the anode part 15b, and the cathode part 1
H ₂ and OH ⁻ ions are generated on the 5a side, and at this time, Mg ions and Ca ions in the seawater are generated as magnesium hydroxide, calcium carbonate or the like on the electrode surface of the cathode portion 15a by the electrolysis action. To deposit. Such a precipitate causes the above-mentioned problems and is not preferable for the electrolytic cell. Further, such a precipitate is likely to be deposited on the cathode end portion where the current is likely to concentrate.

In this respect, according to the bipolar electrode 15 of the present structure, the length of the cathode portion 15a is set longer than that of the anode portion 15b as described above, so that the current concentration described above occurs. It's getting harder. As a result, the amount of precipitation of magnesium hydroxide, calcium carbonate, etc. described above can be suppressed to a small amount due to the small current concentration. In particular, as shown in FIG. 5, the cathode portion 15a is arranged so that the anode portion 15b of the other adjacent two-pole electrode 15 faces the central portion of the cathode portion 15a of the one adjacent two-pole electrode 15. By arranging the end portion of the above to be located outside the end portion of the anode portion 15b by the length Lx, it becomes possible to more effectively prevent the above-mentioned current concentration and suppress the generation amount of precipitates. it can. The dimension Lx is preferably longer than the dimension T between the electrodes.

Further, it is preferable that all the bipolar electrodes 15 provided in the electrolytic cell 11 have the above-mentioned configuration, but it is also possible to use only the upstream side and the downstream side in the flowing direction of seawater or only the upstream side in the electrode configuration described above. A practically sufficient effect can be obtained.

The data shown below show various characteristics when the vertical electrolytic cell according to the example was used for 3 months.

Seawater temperature (23 to 25 ℃) Current efficiency (88 to 94%) Electrolytic current (30A) Electrolytic voltage (11 to 12V) Electrode size (3mm) Electrolytic cell stage number (3 stages) Electrode size (100 x 255mm) Electrode Anode size (100 × 100 mm) Chlorine generation rate (104 g / h) Electrolytic seawater volume (0.6 m ³ / h) Tank outlet chlorine concentration (173 ppm) As shown by this data, in the vertical electrolytic cell of this structure According to this, even after the use for 3 months, the electrolysis capacity is hardly deteriorated. By the way, the first
In the electrolytic cell having the conventional structure as shown in the figure, there is a problem that the electrode is clogged with a deposit after being used for about 2 weeks. Therefore, according to the electrolytic cell of the present structure which prevents the concentration of current as the electrode structure as described above, it becomes possible to maintain the processing capacity of the electrolytic cell for a long period of time, which is a great effect in practical use. Is played.

In addition, the electrolytic cell of this structure includes a cylindrical outer cylinder 11a and an upper lid 11b.
Also, the electrode support box 14 is provided in an outer cylindrical body including the lower lid 11c. Therefore, it is sufficient to design and manufacture the outer cylindrical body only in consideration of its pressure resistance strength, so that it becomes possible to make the outer cylindrical body cylindrical so as to sufficiently withstand the internal pressure with respect to the anhydrous water flowing into the outer cylindrical body. It is possible to reduce the weight by reducing the thickness. Further, since the electrode support box 14 is provided in such an outer cylinder, it is not necessary for the electrode support box 14 to consider the pressure of the seawater. Therefore, the electrode support box 14 can be constructed by appropriately using PVC or the like, which is weak in strength but is excellent in electrical insulation. Further, since the electrode support box 14 is not required to have strength against the pressure of seawater as described above, it is possible to obtain an effect such as a square tube structure suitable for supporting a flat plate-shaped electrode.

The present invention is not limited to the above embodiment. For example, the number of electrodes and the number of constituent stages thereof may be determined according to the specifications required for the electrolytic cell. Further, the size and the like may be set according to the specifications. Further, in FIG. 2, an electrode formed of only the anode part 15b is used as the electrode provided on the uppermost stage, and an electrode provided on the lowermost stage is
Although the case where the electrode substantially including only the cathode portion 15a is used is shown, the electrode structure may include the following aspects.

That is, regarding the electrode provided on the uppermost stage, the cathode portion 15a
Since it is unnecessary, an electrode structure having only an anode part 15b in which platinum is plated on the entire surface of an electrode plate made of a titanium material or coated with a platinum group metal or its oxide is provided at the bottom stage. As for the electrodes, the anode part 15b is not necessary, so the electrode structure is made up of only the cathode part 15a formed of one electrode plate made of titanium material.

If the internal space of the electrolytic cell 11 has a margin, it is functionally useless, but as an electrode provided in the uppermost stage and the lowermost stage, as shown in FIG.
b and the cathode part 15a are used as they are, the cathode part 15a connected to the anode part 15b is connected to the terminal plate 18 for the uppermost electrode, and the cathode part 15a is connected for the lowermost electrode. It is assumed that the anode portions 15b connected to are connected to the terminal plate 19, respectively. In short, the present invention can be variously modified and implemented without departing from the scope of the invention.

According to the present invention, the following operational effects can be expected.

(A) The length of the cathode portion of each bipolar electrode is set longer than the length of the anode portion, and the anode portion of one adjacent two-pole electrode is the same as that of the other adjacent two-pole electrode. Since the position is set so as to face the central portion of the cathode portion, the end portion of the cathode portion is located outside the end portion of the anode portion. By setting such a positional relationship, it becomes difficult for current concentration to occur at the end portion of the cathode portion, and it is possible to suppress the occurrence of precipitates such as magnesium hydroxide and calcium carbonate at the end portion of the cathode portion. it can.

(B) An electrode supporting box made of an insulating cylindrical body is provided inside the outer cylindrical body, and a plurality of bipolar electrodes are arranged and supported in the electrode supporting box in a predetermined manner so that their side surfaces face each other. Since it is configured to do so, it is possible to provide the outer cylindrical body with the pressure resistance against the inflowing seawater. Therefore, it is not necessary to consider the mechanical strength of the electrode support box itself, and it is possible to select and form a member mainly having excellent electrical insulation.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a conventional vertical electrolytic cell, FIG. 2 is a vertical sectional view showing a schematic configuration of a vertical electrolytic cell according to an embodiment of the present invention, and FIG. The figure which shows the structure of the DD cross section of the Example structure shown, FIG. 4 is a figure which shows the structure of the bipolar electrode in an Example, FIG. 5 is a figure which shows the arrangement structure of an electrode, and the electric current flow between electrodes. is there. 11 ... Electrolyzer, 11a ... Outer cylinder, 11b ... Upper lid, 11c ... Lower lid, 1
2 ... Inlet nozzle, 13 Outlet nozzle, 14 ... Electrode support box, 14a,
14b ... Support frame, 15 ... Bipolar electrode, 15a ... Cathode part, 15b ... Anode part, 16 ... Spacer, 17 ... Insulation bolt, 18, 19 ... Electrode terminal plate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Keiichiro Ishiguro, 12 Nishiki-cho, Naka-ku, Yokohama-shi, Kanagawa Mitsubishi Heavy Industries, Ltd. Yokohama Works (56) References JP-A-50-79484 (JP, A)

Claims (1)

[Claims] 1. An external cylinder having an inlet nozzle and an outlet nozzle, an electrode support box made of an insulating cylinder provided inside the external cylinder, and a plurality of electrodes arranged and supported in the electrode support box. And two bipolar electrodes, each bipolar electrode being a plate-shaped electrode in which the length of the cathode portion is set longer than the length of the anode portion, and each bipolar electrode is arranged in the horizontal direction. The first and second electrode groups arranged are arranged so that they are relatively offset by ½ pitch in the vertical direction, and the two-pole electrodes of each group are alternately adjacent to each other at regular intervals. The vertical electrolytic cell is characterized in that the anode part of one adjacent two-pole electrode is positioned so as to face the central part of the cathode part of the other adjacent two-pole electrode.