JPS58217683A - electrolytic cell - Google Patents

Abstract

PURPOSE:To constitute a multi-tank type electrolytic cell free from the leakage of a liquid and capable of using a flat ion exchange membrane, by a method wherein an anode is attached to a frame for constituting the anode chamber of a conventional electrolytic cell to which an asbesto diaphragm method is applied through a current supply rod and the current supply rod, an anode liquid supply port and a liquid-gas discharge port are provided to the frame. CONSTITUTION:Plural ion exchange membranes 17 used in the electrolysis of an aqueous solution are held between a frame 13 for constituting a cathode chamber and a frame 3 for constituting an anode chamber alternately in a watertight and airtight manner. Cathode metal nets 14 are respectively provided to the front and the back surfaces of the frame 13 for constituting the cathode chamber under tension and a current collector, a cathode liquid supply port 21, a cathode liquid and gas discharge port 22 and a perforated support member 23 are provided to the frame 3. An anode 5 is attached to the frame 3 for constituting the anode chamber through a current supply rod 6 and, other than this current supply rod 6, an anode liquid supply port 9 and an anode liquid and gas discharge port 20 are provided thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel filter press type monopolar type, ie, ion exchange membrane method multi-vessel type and unipolar type electrolytic cell for an aqueous alkali chloride solution.

Electrolysis of aqueous alkali chloride solutions has been carried out for a long time.
Currently, asbestos diaphragm electrolytic cells, in which an asbestos diaphragm is installed between an anode and a cathode, are most commonly used industrially.

However, when using this asbestos diaphragm method electrolytic cell,
Since the asbestos diaphragm is a liquid-permeable filtration membrane, a large amount of alkali chloride is mixed into caustic alkaline products, which has been a problem in terms of usage and product refining costs.

In recent years, in order to eliminate these drawbacks, an ion exchange electrolysis technique using a cation exchange membrane instead of an asbestos diaphragm has been developed and is now in the stage of practical application. In this electrolysis technique, a filter press type bipolar electrolytic cell using, for example, a fluororesin-based ion exchange membrane Nafion (trade name of DuPont) or the like is used.

However, such electrolytic N is completely different from the asbestos diaphragm electrolytic cell that has been widely used in the past. That is, the shapes and structures of the cathode, anode, and electrolytic cell differ between the filter press type and the finger type or flattened tube type, between the bipolar electrolysis method and the monopolar electrolysis method, and even between the ion exchange Since there is a big difference between the method of installing and attaching a membrane and the method of attaching an asbestos diaphragm, an ion-exchange removal electrolytic cell is manufactured using a conventional asbestos diaphragm method electrolytic cell or by partially modifying it. It is difficult to do so.

Therefore, when adopting ion exchange membrane technology, a new electrolytic cell is required, which poses a heavy economic burden and is an obstacle to its practical application.

Note that the finger type electrolytic cell for the asbestos diaphragm method mentioned above includes J, Varnish, Sconce (, y, s).

5conce) "Chlorine: Its Production, Properties and Uses"
(Chlorine Its M anull Act
ure, Properties and Uses)
, Robert 8I, - Krieger Publishers 1972 (Ro
bert E, Krieger Publication
Typical examples of the flattened tube type are schematically shown in Figure 5-12 (A) and B of the same figure on page 93, respectively, and the actual use of the finger type is shown. A schematic perspective view of the state can be found in the Encyclopedia of Chemical Technology by Kirk-Othmer.
ediaof Chemical Technology
y) Published by Willy Interscience (AWil
ey-Interscience Publica-t
ion) 3rd edition, Volume 1, page 816.

As mentioned above, in order to overcome the major obstacles in installing new ion exchange membrane electrolytic cells, recently, most of the finger type or flattened tube type electrolytic cells used above have been used as they are, and ion exchange membranes have been attached to them. Proposals have been made to make modifications such as installing a special frame for the ion-exchange membrane method.

This modified electrolytic cell is technically and economically advantageous in that the conventional asbestos membrane method electrolytic cell including the power supply equipment can be used almost as is, but the ion exchange membrane is installed in the gap between the anode and cathode. In order to install the membrane, it is necessary to process the fluororesin ion exchange membrane, which is usually only available in the form of a flat film, by pasting it into a bag, cylinder, or other various shapes. However, the above-mentioned fluororesin-based ion exchange membranes have been viewed as problematic because of their poor workability and lack of reliability in terms of watertightness, airtightness, etc. even with conventional bonding methods such as thermal bonding.

Therefore, an object of the present invention is to create an electrolytic cell using a flat ion exchange membrane and making use of the conventional asbestos diaphragm electrolytic cell equipment as much as possible.

As a result of extensive research with this aim in mind, the present inventors have found that the anode, anode base, power supply equipment (anode side), current collection equipment (cathode side), etc. of the conventional asbestos diaphragm electrolytic cell can be used almost as-is. I was inspired to invent a Urufilter press monopolar ion exchange dehydration electrolysis tank.

That is, the gist of the present invention is that a plurality of ion exchange membranes for aqueous solution electrolysis are alternately held watertightly and airtightly between a frame for configuring a cathode chamber and a frame for configuring an anode chamber, and the frame for configuring the cathode chamber is A wire mesh for the cathode is stretched on both the front and back surfaces of the frame, and the mounting frame is provided with at least a current collector, a catholyte, and a gas supply/discharge port, and the anode is connected to the frame for forming the anode chamber through a power supply rod. The present invention is a multi-vessel type electrolytic cell using an ion exchange membrane method, in which the mounting frame is provided with at least the above-mentioned power supply rod, an anolyte supply port, and a liquid-gas discharge port.

Embodiments of the electrolytic cell according to the present invention will be described in detail below with reference to the drawings.

Figure 1.2 is a plan view and a cross-sectional view taken along the line n-■, showing a state in which two anodes are lined up and fixed by power supply rods within an anode chamber configuration frame constituting an electrolytic cell according to the present invention. be.

In addition, in FIGS. 1 to 6, the same parts are indicated using the same numbers.

Reference numeral 1 denotes a main body for forming an anode chamber, which is surrounded by a frame 3 for forming an anode chamber, and has an anode 4.4 fixed therein by power supply rods 6, 6.

The anode chamber configuration frame 3 is made using a C channel and has a U-shaped cross section opening in the outer circumferential direction, so that it can be used in conjunction with the cathode chamber configuration frame 13 (FIGS. 3 to 5), which has a similar shape as described later. The ion exchange membrane can be sandwiched between the membranes with good watertightness and airtightness.

Of course, the present invention does not limit the frame to the C channel. The frame 3 is provided with holes 2.2 at appropriate positions for inserting bolts for superimposing and tightening multiple frames. Of course, for overlapping and tightening the anode and cathode chamber frames, in addition to the method of using the bolts and nuts, a method of simultaneously tightening a plurality of sets of chamber frames integrally using hydraulic pressure or the like may be used. The three frames for forming the anode chamber must be made of a material that is oxidation resistant, such as chlorine resistant, so titanium or a titanium alloy is usually used, but the present invention is not limited to these materials.

The power supply rod 6 is inserted into the perforation 8 provided in the U-shaped bottom of the frame 3, and the seven lunges are inserted and airtightly fixed.
In order to prevent the anode 5 from shaking, the tip is also attached to the opposing frame 3.
It may be positioned in a concave fixing guide 10 provided in the. Of course, the power supply rod 6 and the frame 3 may be fixed by welding.

The anode 5 may be made of two wire mesh flat plates sandwiching a power supply rod, or the wire mesh flat plate may have a cylindrical shape with a rectangular cross section, and the power supply rod is welded and fixed to the center of the plate. Sometimes. However, it goes without saying that a so-called expander-pull anode, in which a spring attached to a power supply rod or anode wire mesh is used, is also used to shorten or finely adjust the distance between the two electrodes.

The material of the power supply rod is selected from a material that has high rigidity, good conductivity, and good corrosion resistance against electrolyte solution, but corrosion-resistant plating may be applied to increase the corrosion resistance against electrolyte solution.

Usually a copper-titanium composite is used.

The wire mesh or flat plate of the anode is selected from materials that have high rigidity, good conductivity, low chlorine overvoltage, and good corrosion resistance against electrolyte, and these properties may be imparted by surface plating. Usually, a titanium wire mesh plated with ruthenium oxide, iridium oxide, platinum/iridium, platinum/ruthenium oxide, platinum/palladium oxide, or the like is preferably used.

As described above, the frame for constructing the cathode chamber in which the anode is incorporated is provided with an anolyte supply port 19 and an anolyte and gas discharge port 20. The lower bolt portion 9 of the power supply rod 6 can be used for fixing it to the anode base, which will be described later.

The number of anodes to be attached to the anode chamber configuration frame 3 is not particularly limited, and one or more anodes may be attached as necessary, but two are usually attached from the viewpoint of overall size, ease of handling, etc. often.

3 to 5 are a plan view and cross-sectional views taken along lines IV-IV and V-V, showing a state in which cathode wire mesh is stretched on both the front and back surfaces of the cathode chamber configuring frame 13 constituting the electrolytic cell according to the present invention. It is. However, the sectional views shown in FIGS. 4 and 5 are different embodiments, and do not indicate that they exist simultaneously in one cathode chamber configuration main body.

11, a cathode wire mesh 14 is mounted on a frame 13 for forming a cathode chamber.
This is the main body for configuring the cathode chamber, which is stretched and fixed by welding or the like on both the front and back sides of the cathode chamber. Since the frame 13 is formed in the same manner as the anode, the ion exchange membrane can be held between it and the frame 3 for forming the anode chamber with good watertightness and airtightness W. Of course, in the present invention, the mounting frame is not limited to the C channel shown in FIGS. 3 to 5, and may be a thick plate-shaped body. However, it is more convenient to use the C channel in order to provide a large number of holes 12.degree. 12 at appropriate positions for inserting bolts for fastening the frames 3 and 13 together.

The frame 13 for forming the cathode chamber and the wire mesh 14 for the cathode have good conductivity, good alkali resistance, and high rigidity.
Due to the need to be made of a material with low hydrogen overvoltage, mild steel, chives, stainless steel, titanium, etc. are usually used, but if necessary, a material plated or coated with a cathode active material may be used.

The cathode 15 formed by the cathode wire mesh 14 may have a planar shape as shown in FIG. 4, but it may also have a convex shape as shown in FIG. 5 to adjust the distance between the two electrodes. It can also be brought into close contact with the electrode.

Note that in order to support the positional relationship between the two cathode wire meshes, perforated support bars 23 may be provided between opposing sides of the cathode chamber configuration frame 13.

The cathode chamber configuration frame 13 has at least a catholyte supply port 2.
1. In addition to the catholyte and gas outlet 22, an electric body must be installed.

It is tightened using a bolt (not shown) that passes through the main body 1 for forming the anode chamber, the main frame 3 for forming the cathode chamber, and the frame 13 for forming the cathode chamber.

It is preferable that a gasket having a buffering property be used between the ion exchange membrane 17 and each of the frames 3 and 13 to improve watertightness and airtightness.

The conductive fixing rod screwed into the integrated filter press l is inserted and fixed in this manner.

As explained above, the present invention has completed a multi-vessel electrolytic cell that utilizes as much of the components of the conventional asbestos diaphragm method electrolytic cell as possible and uses a flat ion exchange membrane that is free from leakage. It has been found that the simple structure of the present invention has advantages both technically and economically.

[Brief explanation of the drawing]

Figure 1 is a plan view of the main body for an anode chamber configuration, Figure 2 is a sectional view taken along the line ■-■, Figure 3 is a plan view of the main body for a cathode chamber configuration, and Figure 4 is an IV
5 is a sectional view taken along the line V--IV showing another embodiment, and FIG. 6 is a sectional view taken along the line V--IV showing another embodiment. 1...Main body for anode chamber configuration, 2.2'...
... Hole 3 ... Frame for anode chamber configuration, 4 ...
...wire mesh for anode, 5...anode, 6.
...Power supply rod, 9 ...Power supply rod lower bolt part, 10 ... Fixing guide, 11 ... Main body for cathode chamber configuration, 12 ...
...hole, 13... frame for cathode chamber configuration, 14.
...Wire mesh for cathode, 15...Cathode, 16...Anode base, 17...Ion exchange membrane, 18...For fixing power supply rod hole, 1
9...Anolyte supply port 20...Anolyte and gas discharge port, 21...
...Catholyte supply port 22... 〃 and gas discharge port, 23...
...Perforated support beam. Patent applicant Showa Denko Co., Ltd. Showa Engineering Link Co., Ltd. Agent Patent attorney Sei Kikuchi - Figure 3

Claims (7)

[Claims] (1) A plurality of ion exchange membranes for aqueous solution electrolysis are alternately held between a frame for forming a cathode chamber and a frame for forming an anode chamber in a watertight and airtight manner, and the front and back surfaces of the frame for forming a cathode chamber are respectively provided. A wire mesh for the cathode is stretched, and the mounting frame has at least a current collector,
A catholyte and gas supply/discharge port are provided, the anode is attached to the frame for anode chamber configuration via a power supply rod, and the mounting frame is provided with at least the power supply rod, the anolyte supply port, liquid, and gas discharge. An ion-exchange membrane multi-cell electrolytic cell characterized by having an outlet. (2) An electrolytic cell according to claim 1, in which the power supply rod is fixed to a common anode base. (3) The electrolytic cell according to claim 1, wherein the frame for forming the cathode chamber and the frame for forming the anode chamber are each made of mild steel and titanium, and are formed with a C channel opening in the outer circumferential direction. (4) The electrolytic cell according to claim 1, wherein the cathode wire mesh is stretched outwardly in a convex shape from the frame for forming the cathode chamber. (5) The electrolytic cell according to claim 1, wherein the anode is a cylindrical dimensionally stable insoluble metal electrode made of wire mesh or metal plate and having a rectangular cross section into which a power supply rod is inserted and fixed. (6) The anode is placed between two parallel electrodes with variable spacing between the power supply rods.
The electrolytic cell according to claim 1, which is a flat body made of a wire mesh or a metal plate. (7) The electrolytic cell according to claim 1, wherein the power supply rod is fixed at two opposing sides of the anode chamber configuration frame.