JPS616288A - Vertical electrolytic cell - Google Patents

Abstract

PURPOSE:To provide a vertical electrolytic cell which prevents the local current concentration of electrodes by disposing plural pieces of the bipolar electrodes in which the cathodes are longer than the anodes into plural stages in an electrode supporting box in such a manner that the ends of the cathodes are longer than the ends of the anodes. CONSTITUTION:The vertical electrolytic cell 11 is provided with the electrode supporting box 14 constituted with supporting frames 14a, b consisting of an electric insulator such as plastic on the inside of an outside cylinder 11a having inlet and outlet nozzles 12, 13 for an electrolyte such as sea water and providing with upper and lower caps 11b, c. Plural pieces of the bipolar electrodes 15 constituted with the anodes 15b plated with Pt, etc. in one of the regions bisecting the electrode plates consisting of a Ti material, etc. and the cathodes 15a in the other region are disposed with multiple stages by means of bolts 17, spacers 16, etc. into the above-mentioned box 14. The above- mentioned cathodes 15a are set longer in length than the anodes 15b and the electrodes are so disposed that the ends of the cathodes are longer than the ends of the anodes 15b facing the same. The current concn. at the terminal of the electrodes 15 is thus averted and the sticking of the by-products from the sea water to the electrodes is prevented, by which the long-period use of the cell is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a two-electrode vertical electrolytic cell that avoids current concentration at the electrode terminals.

As an electrolytic cell for electrolyzing seawater, there is conventionally known as a two-electrode type electrolytic cell having a vertical structure as shown in FIG. In Figure 1, (a) shows the longitudinal cross-sectional structure of a TA type electrolytic cell, (b) is its A-A cross-sectional view, and (C) is its B-
-B sectional view, and (d) is an enlarged view of the C portion. Therefore, in this vertical electrolytic cell, a plurality of bipolar electrodes 2 are provided inside an electrolytic cell body 1 in parallel and facing each other with a partition plate 3 interposed therebetween, and in multiple stages. The iI flow supplied through the bus bars 6.1 respectively connected to the lower terminal board 4 and upper terminal board 5 of the plurality of
It is configured to electrolyze seawater flowing through the polar electrode 2 and flowing into the electrolytic cell body 1. The seawater flows into the electrolytic Hashimoto from an inlet nozzle 8 provided at the bottom of the electrolytic cell body 1, flows between the bipolar electrodes 2, and then flows through an inlet nozzle 8 provided at the bottom of the electrolytic cell body 1. It is designed to be discharged from an outlet nozzle 9.

However, in a vertical electrolytic cell with such a configuration, when one looks at the pair of bipolar electrodes 11i2 between the partition plates 3, i! acts as (+)tii! li 2 and (-
) The effective lengths (effective lengths) of the electrodes 2 that act as poles are equal. For this reason, a phenomenon occurs in which the current is concentrated at the end of the electrode 2, which acts as a (-) diffuser, and by-products such as magnesium hydroxide produced by the decomposition of the seawater are likely to be deposited at the current concentrated portion. Such problems arose. Moreover, such deposits (precipitates) cause problems such as blocking the seawater flow path between the two electrodes 2 and causing wear and tear on the anode material.

The present invention was made in consideration of these circumstances, and its purpose is to provide a vertical type with a highly practical structure that eliminates the conventional disadvantages by preventing local current concentration in the 11 poles. Our purpose is to provide electrolytic cells.

In the vertical electrolytic cell according to the present invention, an electrode support box is provided inside the outer cylinder, and a plurality of bipolar electrodes in which the length of the cathode is set longer than the length of the anode are placed in the electrode support box as described above. II! Earth distribution (2
) It is characterized by having a structure in which the support box is arranged in multiple stages over the entire support box.

Hereinafter, one embodiment of the present invention will be described 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 diagram showing a DD sectional structure thereof.

The electrolytic cell 11 includes a cylindrical outer cylinder 11a, and an upper lid 11b and a lower lid 11, each of which has its upper and lower surfaces closed.
C, forming a solid having a predetermined compressive strength. An inlet nozzle 12 for introducing seawater is installed at the lower part of the outer cylinder 11a, and an outlet nozzle 13 for discharging the seawater is installed at the upper part. Seawater to be subjected to electrolysis is made to flow into the electrolytic cell 11 through these nozzles 12 and 13.

An 11-pole support box 14 made of an electrically insulating material such as plastic and having a rectangular cylindrical structure is provided within the electrolyte 11. This electrode support box 14 includes, for example, first and second support frames 14a as shown in FIG.

1411 in a rectangular frame. Inside this electrode support box 14, a plurality of two inert electrodes 15 are arranged and fixed in multiple stages in parallel with a predetermined gap between them.

Specifically, the plurality of bipolar electrodes U15 are stacked in parallel with each other via a spacer 1G having a thickness of D, and are supported in a skewered manner by insulating bolts 17 and fixed between the support frames 14b.

The bipolar electrode 15 provided in the electrode support box 14 in this way is made by dividing one electrode plate into two parts, for example, as shown in FIG. 4, and making one part a cathode part 15a and the other part an anode part 15b. Has a structure. This bipolar electrode 15 is constructed by plating one region of an electrode plate made of titanium material with platinum or coating it with a platinum group metal or its oxide to form an anode portion 15b, and the other region as a cathode. 15a. Then, the length of the cathode portion 15a is determined as Fj! It has a configuration that is set longer than the quality of the pole portion 15b.

A plurality of bipolar electrodes 15 having such a structure are arranged in the electrode support box 14 with cathode portions 15a and anode portions 15b facing each other between mutually opposing electrodes 15, as shown in FIG. be done. In addition, regarding the electrode of the anode part 15b provided in the upper stage, since the cathode part 15a is unnecessary,
It is also possible to have an electrode structure in which the entire surface of the single electrode plate made of titanium material is plated with platinum or coated with a platinum group metal or its oxide. Further, as for the electrode of the cathode section 15a provided at the lowest stage, since the anode section 15b is unnecessary, the electrode structure may be made of only titanium material.

Thus, the electrode consisting only of the uppermost anode portion 15b is electrically connected to the electrode terminal plate 18, and connected to an external current lead (bus bar) via this electrode terminal plate 18. There is. Similarly, the lowest cathode section 15
The electrode consisting only of a is electrically connected to an electrode terminal plate 19, and is connected to an external current lead (
busbar). The current supplied through these electrode terminal plates 18 and 19 flows in series from the uppermost electrode to the lowermost electrode in the electrolytic cell 11 as shown in FIG. ing.

Thus, according to the vertical electrolytic cell having such a structure, the above-mentioned 2.
The seawater flowing between the electrodes 15 is electrolyzed by the current flowing between the electrodes 15 . Due to this electrolysis of seawater, Cβ2 ions are generated on the anode portion 15b side, and H2 and OH− ions are generated on the cathode portion 15a side. Also, at this time, due to the electrolytic action, MO ions and Cat ions in the seawater are converted to magnesium hydroxide and rj! Calcium oxide is deposited on the electrode surface of the cathode section 15a.

Such precipitates cause the problems mentioned above,
This is unfavorable for electrolytic cells.

Further, such precipitates tend to be deposited at the cathode end where current tends to concentrate.

In this regard, according to the bipolar electrode 15 of this structure, the length of the cathode portion 15a is set longer than the length of the anode portion 15h, as described above, so that the current concentration described above is prevented. It's getting harder to wake up. As a result, the amount of precipitation of the above-mentioned magnesium hydroxide, calcium carbonate, etc. can be suppressed by the amount of less concentration of electric i. In particular, the cathode section 1
If the surface of the electrode portion 5a facing the anode portion 15b is lengthened by L as shown in FIG. be. Incidentally, it is preferable that the above-mentioned dimension is set longer than the dimension between the electrodes.

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

The data shown below shows the specific characteristics when the vertical electrolytic cell according to the example was used for three months.

Seawater + m degree (23~25℃) Current efficiency (88~94%
) Electrolysis current (3OA) Electrolysis voltage (11~12V
) Dimension between electrodes (3 m) Number of electrolytic cell stages (3 stages) Electrode dimension (100x 2551H4) Anode dimension of electrode < 100x 100 M)m element fl
ji (104 (1/h) Electrolyzed seawater! (0.6 m3/h) Chlorine concentration at tank outlet (173 ll111) As shown by this data, according to the vertical electrolytic tank of this structure, after 3 months of use Even if the
In an electrolytic cell with a conventional structure as shown in the figure, approximately 23! There is a problem in that the space between the electrodes becomes blocked by precipitates when used between the electrodes. Therefore, according to the electrolytic cell of this structure, which uses the electrode structure as described above to prevent current concentration, it is possible to maintain the processing capacity of the electrolytic cell for a long period of time, and it has a great practical effect. is played.

Moreover, the electrolytic cell of this structure has a cylindrical outer tank and an electrode support box provided in the outer tank. For this reason, it is only necessary to design and manufacture the outer tank by considering only its pressure-resistant strength, so it is possible to make the outer tank into a cylindrical shape that can sufficiently withstand the internal pressure of seawater flowing into it, and its plate thickness It is possible to reduce the weight by making it thinner. Furthermore, since the electrode support box is provided inside such an outer cylinder,
As for the electrode support box, there is no need to consider the pressure of the seawater. Therefore, the electrode support box can be constructed by appropriately using PVC or the like which is weak in strength but has excellent electrical insulation properties. Furthermore, since the electrode support box is not required to have strength against the pressure of seawater, it can have the advantage of having a rectangular cylindrical structure suitable for supporting flat electrodes.

Note that the present invention is not limited to the embodiments described above. For example, the number of electrodes, the number of stages thereof, etc. may be determined depending on the specifications required for the electrolytic cell. Further, its size etc. may be set according to the specifications. In short, the present invention can be practiced with various modifications without departing from the gist thereof.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a schematic configuration of a conventional vertical electrolytic cell, FIG. 2 is a vertical cross-sectional view showing a schematic configuration of a vertical electrolytic cell II according to an embodiment of the present invention, and FIG. D-D of the example structure shown
FIG. 4 is a diagram showing the configuration of a cross-section, FIG. 4 is a diagram showing the configuration of bipolar electrodes in the example, and FIG. 5 is a diagram showing the arrangement of the electrodes and the flow of current between the electrodes. 11... Electrolytic cell? 1a...outer cylinder? 1b... Upper lid, 11c... Lower lid, 12... Inlet nozzle, 1
3-output nozzle, 14...electrode support box, 14a, 1
4b...Support frame, 15...Bipolar electrode, 15a...
Cathode part, 15b... Anode part, 16... Spacer, 1
7... Insulating bolt, 18.19... Electrode terminal plate. 5 Figure 4

Claims (1)

[Claims] An electrode support box is provided inside the outer cylinder, and in this electrode support box, a plurality of two
A vertical electrolytic cell characterized in that electrodes are arranged in multiple stages throughout the electrode support box so that the end of the cathode is longer than the end of the anode.