US3902984A

US3902984A - Bipolar electrolytic cell

Info

Publication number: US3902984A
Application number: US448961A
Authority: US
Inventors: Naoshi Yoshida; Shotaro Kiga; Takashi Yamamoto; Kazuo Shirasaki
Original assignee: Nippon Soda Co Ltd
Current assignee: Nippon Soda Co Ltd
Priority date: 1973-03-13
Filing date: 1974-03-07
Publication date: 1975-09-02
Anticipated expiration: 1992-09-02
Also published as: FR2221184A1; DE2412132B2; JPS49117398A; DE2412132A1; NL7403331A; FR2221184B1; CA1036978A; BE812252A; GB1441063A; DE2412132C3; JPS5647267B2

Abstract

An improved bipolar diaphragm electrolytic cell assembly wherein the cell assembly is constructed of a plurality of bipole units which divide the cell into a plurality of single cells and have a structure which can be easily assembled. The connection between the anodic and cathodic portions of each bipole unit comprises a hollow partition having a current connecting plate in the hollow portion of the partition, with electroconductive bars extending from inside the pectinate anodes and cathodes to the current connection plate.

Description

United States Patent Yoshida et al. 1 Sept. 2, 1975 54] BIPOLAR ELECTROLYTIC CELL 3.247.090 4/1966 Forbes 204/254 x 3,755,108 8/1973 Raetzsch ct al 204/255 x Inventors: Naoshi Yoshida; Shotaro Kiga;

Takashi Yamamoto, Omiya; Kazuo Shirasaki, Yokohara, all of Japan Assignee: Nippon Soda Co., Ltd., Tokyo,

Japan Filed: Mar. 7, 1974 Appl. No.: 448,961

[30] Foreign Application Priority Data Mar. I3, 1973 Japan 48-29171 [52] US. Cl. 204/254; 204/256; 204/268; 204/286 [51] Int. Cl. C25B 13/00 [58] Field of Search 204/254, 255, 256, 268, 204/286 [56] References Cited UNITED STATES PATENTS 2,858,263 10/1958 Lucas et al. 204/256 Primary ExaminerJohn H. Mack Assistant Examiner-W. 1. Solomon Attorney, Agent, or Firm-George B. Oujevolk [57] ABSTRACT An improved bipolar diaphragm electrolytic cell assembly wherein the cell assembly is constructed of a plurality of bipole units which divide the cell into a plurality of single cells and have a structure which can be easily assembled. The connection between the anodic and cathodic portions of each bipole unit comprises a hollow partition having a current connecting plate in the hollow portion of the partition. with electroconductive bars extending from inside the pectinate anodes and cathodes to the current connection plate.

13 Claims, 17 Drawing Figures PATENT-EDSEP 2191s SHEEY PATENTED SEP 2 I975 SHEET FIG-6 F/G.8

FIG]

ISJIIB i PATENTEUSEP 3, 902,984 SHEET 5 SHEET PATENTED SEP 2 75 F/G./O

EATEHTED 219.75 3,902

SHEET 7 BIPOLAR ELECTROLYTIC CELL BACKGROUND OF THE INVENTION The present invention relates to a bipolar diaphragm electrolytic cell assembly and more particularly to an improved bipolar diaphragm electrolytic cell assembly including a novel bipole unit having improved means for the electrical and mechanical connection between the anodes and cathodes.

BRIEF REVIEW OF THE PRIOR ART In a bipole unit, electrodes are fixed to a partition so that the anodes of one cell may be arranged in a backto-back relationship with the cathodes of the adjacent cell and the electrical contact may be maintained between the two.

The bipolar diaphragm electrolytic cells which are presented by Japanese patent publication No. 5,l95 l, and Japanese patent application No. 21946, 1970 have been hitherto known. The former is a typical bipolar electrolytic cell which is well-known as the Nisso type. The latter, which was published in the bulletin of the Japan Soda Industry Association Soda and Chlorine Vol. 22, No. 254, is an improvement of the former electrolytic cell.

Both of these electrolytic cells have as one of their features the characteristic which is set forth in the claim of Japanese Patent Publication No. 5, I95 l, namely that the rectangular electrolytic cell is divided into a plurality of single cells by a partition arranged perpendicularly to the major axis of the rectangular electrolytic cell. Each single cell includes many graphite anode plates fixed to the partition in the same direction and many cathodes constructed of metal wire screen in a shape of flat bag and arranged at the side opposite to that of the anode plates. Each cathode is fixed to a backscreen as a comblike assembly and is covered with a permeable diaphragm. The partition between a single cell and an adjacent single cell has a hollow passage portion as a passage for catholyte and the anode is electrically connected with the cathode at said hollow portion of the partition.

On the other hand, the difference between these two cells is that the former electrolytic cell is box-shaped and every anodes and cathodes are fixed to the partition, while the latter electrolytic cell is channel-shaped (a shape that the opposite two side walls of the box are removed) and the anodes and the cathodes of both ends of electrolytic cell are directly fixed to the side walls and said side walls are fixed to the electrolytic cell like a flange to form a box-shaped electrolytic cell.

The present invention further improves the latter type cell. The electrolytic cell of the present invention has a metal anode instead of a graphite anode and a novel mechanical and electrical connection between the electrodes.

In the above-mentioned electrolytic cell of Japanese patent application No. 2I946,1970, lead welding is adopted for the mechanical and electrical connection between the anodes and the cathodes or the mechani cal connection of the anode to the anode side wall. In such an arrangement method, the anode must be fixed to the wall so that the rubber lining may not be damaged by heat. While in the present invention. the components are secured by screws.

Thus. object of the present invention is to provide an improved bipolar diaphragm electrolytic cell which can easily be assembled and disassembled. Another object of the invention is to provide a bipolar diaphragm electrolytic cell having improved mechanical and electrical connections between the cathode and anode.

As used herein the term bipole unit is used to describe a bipolar assembly wherein the anodes of one cell are mounted to a partition in a back-to-baek relationship with the cathodes of an adjacent cell and electrical contact is maintained between the two.

The partition, which serves as a supporting wall for the anodes and cathodes in the back-to-back relationship, physically separates the cells within the over-all cell housing. The term single cell is used to describe each cell separated by the partition. The single cell includes the anodes of one bipole unit and the cathodes of the adjacent bipole unit. The term anode side wall" and cathode side wall are used to describe the peripheral wall of the cell for mounting the anodes of the end single cell and the cathodes of the opposite end single cell respectively.

Other and further objects, features and advantages of the invention will appear more fully from the following description and accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I shows a plan view of the electrolytic cell of the present invention with portions of the cell broken away.

FIG. 2 shows a side view of the electrolytic cell with portions of the cell housing and the anode broken away.

FIG. 3 shows a plan view of the cover of the electrolytic cell.

FIG. 4 shows an elevational view of the partition with portions broken away.

FIG. 5 shows a longitudinal sectional view of the partition taken on line 5-5 of FIG. 4.

FIG. 6 shows a side view of the anode with portions of the side of the anode broken away.

FIG. 7 shows a plan view of the anode.

FIG. 8 shows an clevational view of the anode.

FIG. 9 shows a side view of the cathode with portions of the side metal wire screen broken away.

FIG. 10 shows a plan view of the cathode assembly with portions broken away.

FIG. 11 shows an elevational view of the cathode assembly with portions broken away.

FIG. 12 shows an elevational view of the current connecting plate with portions broken away.

FIG. 13 shows a longitudinal sectional view of the current connecting plate taken on line 13-13 of FIG. 12.

FIGS. 14 and 15 show a longitudinal sectional view of the essential part of the bipole unit illustrating alternate means for mounting the anodes and cathodes to the partition.

FIG. 16 illustrates means for mounting the anodes to the anode side wall of the cell.

FIG. 17 illustrates means for mounting the cathodes to the cathode side wall of the cell.

DETAILED DESCRIPTION FIGS. 1 and 2 show a plan view and a side view of the whole cell of the present invention respectively for il lustrating a preferred embodiment of the present inven tion.

The cell housing 1 is channel-shaped (a shape that the opposite two side walls of the box are removed and the upper side is open) and its inner surface has a suitable protective coating, such as of rubber, in order to prevent corrosion. The cell housing 1 has guides 11 for mounting or dismounting a partition 6, openings 12 therethrough for extending the outlet pipe 62 of the catholyte, and openings 13 for mounting the anolyte level gage. Channel-shaped cell housing 1 is connected with the anode side wall 2 and the cathode side wall 3 like a flange to form the box-like outer shell of the cell. There is no incovenience if the cell housing 1 is in a body with the anode side wall 2, but the cathode side wall 3 should be removably connected to the cell housing 1 in order to be able to remove it when renewing the diaphragm. The opening 13 may be only one. The anode side wall 2 has a suitable protective coating, such as of rubber, at the inner surface and has openings therethrough for extending electroconductive bars of the anode 4 outwardly. The cathode side wall 3 also has a suitable protective coating, e.g., rubber, at the inner surface and has an inner chamber for the passage of the catholyte, a window-like opening for mounting the cathode 5, openings therethrough for extending electroconductive bars of the cathode outwardly, a hydrogen outlet pipe 31 and a catholyte outlet pipe 32. The partition 6 has a suitable protective coating, such as of rubber, at the outer surface, and has an inner chamber for the passage of the catholyte, a back plate 65 having openings therethrough for extending the electroconductive bars of the anode, a window-like opening at the side opposite the back plate wherein said window-like opening serves as the passage for the catholyte, a hydrogen outlet pipe 61, and a catholyte outlet pipe 62. The partition divides the whole cell into a plurality of compartments, namely, a plurality of single cells. A catholyte outlet pipe 62 is removably attached to the partition and the partition removing said catholyte outlet pipe is vertically set to the electrolytic cell by bringing it down along the guide 11 after both of the anodes and cathodes are fixed thereto. The anodes 4 and the cathodes are mounted to the anode side wall 2 and the cathode side wall 3 respectively and mounted to the partition 6 in a back-to-back relationship to form a bipole unit. When the bipolar electrolytic cell is assembled, the cathodes of one bipole unit lie between the anodes of the adjacent bipole unit to form a single cell. The partitions are arranged in parallel with the anode side wall and the cathode side wall. The anodes and cathodes are vertical and perpendicular to the partition so that the surfaces of the anodes are parallel to the adjacent surfaces of the cathodes.

As mentioned above, the cell housing, anode side wall, cathode side wall and the partition should have a suitable protective coating at the portions that are in contact with anolyte in order to prevent corrosion.

The bipolar cell of the present invention may be provided with only one bipole unit though a plurality of bipole units are shown in FIGS. 1 and 2. The surface of the cathode is covered with a permeable diaphragm, for example, asbestos, though it is not shown in drawings.

In the cell of the present invention, there is the slight leakage of brine between each adjacent single cells through a small space between a partition 6 and a guide 11, thereby providing an equal level of brine in each single cell. During a typical operation. brine is continuously added to each of the single cells through the corresponding opening 73 (shown in FIG. 3). Therefore such slight leakage of brine does not influence the current efficiency in operation.

FIG. 3 shows a plan view of the cover of the upper side of the cell. The cover is costrueted of iron and the inner surface has a suitable protective coating, such as rubber, and the cover has an opening 71 for removing chlorine, openings 72 for removing hydrogen, openings 73 for feeding brine, an opening 74 for mounting the pressure gage of the anodic compartment and the rupture plate 75. I I

FIG. 4 shows an elevational view of the partition as seen from the side for mounting the cathode and FIG. 5 shows a longitudinal sectional view of the partition 6. The partition, as partly described before, has a pipe 61 for removing hydrogen, a pipe 62 for discharging the catholyte, openings 63 for mounting anodes, a backplate 65, a window-like opening with a frame 64 around it for fixing the cathode assembly thereto closely and a suitable protective coating at the outer surface, such as of rubber.

FIGS. 6, 7 and 8 show respectively a side view. a plan view and an elevational view of one embodiment of a metal anode employed in the present invention. Anode 4 includes a pair of laterally-spaced

walls

41 and 42. The

walls

41 and 42 may be solid plate or may be of a forminous or louvered sheet materials. Anode 4 has one or more of horizontal electroconductive bars 43 and ribs 44 between the

walls

41 and 42 for support of the

walls

41 and 42 and for electrical connection between the bar and the walls wherein said electroconductive bars are disposed between the

walls

41 and 42. The electroconductive bar extends outwardly from the end of the

walls

41 and 42 and has the flange 45 at said extending part close to the walls and further has a spiral groove 46 at the end of the bar. Said flange 45 and said spiral groove 46 serve as means for mounting the anode to the partition and acurrent connecting plate. The

walls

41 and 42 are preferably parallel each other.

The anode preferably includes plural electroconductive bars to fix the anode to the partition stably. The

walls

41 and 42 may be constructed of any suitable anodicallyresistant material, preferably titanium, which surface should be coated with a suitable anodi- Cally-resistant electroconductive surface such as a platinum group metal or the oxide of a platinum group metal. The electroconductive bars 43, are constructed of titanium or may be constructed of any good electroconductive material, such as iron, steel or copper which surface should be coated with titanium.

FIGS. 9, l0 and 11 show respectively a side view, a plan view and an elevational view of one embodiment of the cathode employed in the present invention. The cathodes 5 are constructed of metal wire screen or the like and are covered with a permeable diaphragm, for example, asbestos. The metal wire screen may be of any suitable metal, for example iron. The cathode wall 51 takes a shape of flat bag and is hollow, in the other words, a pair of parallel side walls are joined at their outermost ends and at their upper and lower edges thus forming a chamber enclosed except for the end which opens into the chamber of the partition. All of the cathodes in one single cell are perpendicularly connected to the backscreen 56 at said open ends so as to become one body, thus forming a comb-like cathode assembly. The backscreen 56 has a peripheral flange 57 for mounting the cathode assembly closely to the frame around the window of the partition. The backscreen 56 may be constructed of the same material as the wall 51 and should be covered with a permeable diaphragm as well as the wall 51. Each of the pectinate hollow cathodes has one or more of horizontal electroconductive bars 52 andribs 53 for support connecting the wall 51 and for electrical connection between the bar 52 and the wall 51, wherein said bars 52 and said ribs 53 are disposed in the hollow portion of the cathode. Each catlio preferably includes plural electroconductive bars-tcj fix the cathode-assembly to the partition stably. The electroconductive bar 52 extends outwardly from the open end of the cathode and has a flange 54 at said extending part close to said backscreen 56 and further has a spiral groove 55 at the end of the bar. wherein said flange 54 and spiral groove serve as means for con nectng the cathode to the current connecting plate.

FIGS. l2, 13 are respectively an elevational view and a longitudinal sectional view taken on line 13-13 of FIG. 12 showing a current connecting plate disposed at the inner chamber of the partition. The current connecting plate 8 may be of any suitable cathodicallyresistant and good electroconductive material such as iron, and has openings 81 for connecting anodes and openings 82 for connecting cathodes. The current connecting plate may be one plate connected to all the electroconductive bars of the anodes and cathodes of one bipole unit or may be plural plate, in the other words, in case that the anode and cathode have two electroconductive bars respectively, the current connecting plate corresponds to a plurality of pairs of electroconductive bars of the anodes and cathodes, namely in this case, there are two current connecting plates.

The

opening

81 and 82 should be provided on a zigzag line as shown in FIG. 12.

Referring now to FIGS. l4, I5, 16 and 17, means for mounting anodes and cathodes to a partition or a side wall is explained in detail.

FIG. 14 illustrates means for mounting anodes and cathodes to a partition and for connecting anodes to cathodes through a current connecting plate 8. When assembling the bipole unit shown in FIG. 14, the anodes 4 are first mounted to the partition 6 and then, the cathodes are mounted. The electroconductive bar 43 of the anode extends through an opening 63 in the backplate 65 and is secured by binding the nut 47, wherein the backplate 65 is interposed between the flange 45 and said nut 47. A gasket 48 should be provided between the backplate 65 and the flange 45 and a washer 49 may be provided between the backplate 65 and the nut 47, thereby preventing any leakage between the cathodic compartment and the anodic compartment. The gasket 48 may be any suitable anodically-resistant material which simultaneously has good sealing nature for liquid. The washer 49 may be a spring washer if the gasket or the coating on the partition is of the material that is apt to cause the permanent strain. All the anodes of one single cell are perpendicularly mounted to a partition, thus anodes of a bipole unit take a pectinate shape on the backplate of the partition.

Each of the electroconductive bars 52 of the pectinate cathodes extends through the opening 82 in the current connecting plate 8 and is secured by binding the nut 58, wherein the current connecting plate 8 is interposed between the flange 54 and the nut 58, thus a comb-like cathode assembly is connected to the current connecting plate 8. In this case, the current connecting plate may be secured to the cathode assembly by welding instead of by screw means.

The electroconductive bar 43 of the anode, which extends through the opening 63 in the backplate 65 and is secured by the nut 47, further extends through an opening 81 in the current connecting plate 8 and is secured by binding the nut 410.

The cathode assembly should be designed so that the peripheral flange 57 of the backscreen 56 may exactly fit the frame 64 around the window of the partition, otherwise undue mixing of the anolyte with the catho- Iyte may occur. The nut 410 can be operated through the opening 59 which provides access to said nut 410 and is disposed on the backscreen 56 opposing to the connecting point of the electroconductive bar of the anode with the current connecting plate.

The opening 59 is removably covered with lid 510 which may be constructed of the same type material as used in the backscreen of the cathode assembly or of the incorrosive material such as ebonite or polyfluoroethylene. If the lid is constructed of metal wire screen, the lid should be covered with permeable diaphragm to surve as the cathode surface as well as other part of metal wire screen. As means for removably securing the lid, the lid 510 has a screw and the electroconductive bar 43 of the anode has an opening therethrough for reception of said screw of the lid at the top of the bar 43 as shown in FIG. 14, however said means should not be limited to this.

In the bipole unit of the present invention, the pectinate anodes and cathodes are perpendicular to the partition. When the electrodes are in position of operation, each surface of anodes is parallel with each adjacent surface of cathodes, and a uniform and narrow space can be provided between the anodic and cathodic surfaces.

FIG. 15 illustrates another preferred embodiment of the bipole unit of the present invention. In the embodiment shown in FIG. 14, opcinings for operating the nut 410 are on the backscreen of the comb-like cathode assembly, in the other hand, in the embodiment shown in FIG. 15, openings 66 for operating the nut 58 are on the back plate 65 of the partition. In FIG. 15, anodes are mounted to the backplate 65 of the partition in the same manner as in FIG. 14, however, in this embodiment, the current connecting plate 8 is secured to anodes before securing to cathodes. When assembling the bip'ole unit shown in FIG. 15, the current connecting plate 8 is secured to the end of the electroconductive bar 43 of the anode secured to the back plate 65 by inserting the end of the bar 43 into openings 81 and se' curing with the nut 410. Then the comb-like cathode assembly is mounted to the partition by inserting the electroconductive bars 52 of cathodes into openings 82 and binding the nuts 58 throug openings 66. The openings 66 are disposed on the back plate 65 opposing to each connecting point of the electroconductive bars 52 of the cathodes with the current connecting plate. The openings 66 are covered with removable lids 67, and the lids may be constructed of any suitable noncorrosive material, such as ebonite, polyfluoroethylene, titanium. In FIG. 15, openings 66 take the shape of nut, and lids take the shape of bolt and are screwed in the openings, however, the means are not limited to this. Additionally the method and structure for fixing electrodes to the partition may be the structure shown in FIG. 16. The cathode including the electroconductive bar without a flange for securing the cathode to the current connecting plate and a spiral groove may be employed and the electroconductive bar is secured directly to the current connecting plate by welding and then, the current connecting plate is secured to the anode as mentioned before.

FIG. 16 illustrates means for mounting anodes to the anode side wall 2 and for connecting anodes to the outer electric feeder plate 9. The anode may be mounted to the anode side wall 2 in a manner identical to the mounting of the anode to the back plate of the partition. In FIG. 16, the end of the electroconductive bar 43 of the anode 4 is inserted into the opening 21 for mounting the anode, and the anode is secured to the anode side wall 2 by binding the nut 47, wherein the anode side wall 2 is interposed between the flange 45 and the nut 47.

A gasket 48 should be provided between the flange 45 and the anode side wall 2 and a washer 49 may be provided between the anode side wall 2 and the nut 47. The electroconductive bar 43 of the anode is further connected to the outer electric feeder plate 9 by inserting the end of the bar 43 into an opening in said outer electric feeder plate 9 and binding the nut 410. The inner surface of the anode side wall 2 has a suitable protective coating 22, such as of rubber.

FIG. 17 illustrated means for mounting cathodes to the cathode side wall 3 and for connecting cathodes to the outer electric feeder plate 9. In FIG. 17, the end of the electroconductive bar 52 of the cathode is inserted into the opening 33 in the backplate 36 of the cathode side wall 3 and the cathode is secured by binding the nut 58.

Gaskets

34 and 35 should be provided between the flange 54 and the backplate 36 of the cath ode side wall and between the backplate 36 and the nut 58 respectively, thereby preventing leakge of catholyte through opening 33. The end of the bar 52 is further inserted into the opening of the outer electric feeder plate 9 and secured by binding the nut 511. The outer surface of the wall at the side opposite the back plate 36 has a suitable protective coating 37, such as of rubber. In the bipole unit and the cathode side wall shown in FIG. 17, each hollow portion of cathodes communicates with the chamber being inside of the partition and the cathode side wall through the opening end of the cathode, and forms the cathodic compartment.

By the way, in a conventional electrolytic cell, for example the cell discribed in Japanese patent application No. 5, 1951 or the cell described in Japanese patent application No. 21946, 1970, each flat bag-shaped cathode does not include the electroconductive bar, and the current connecting plate is directly secured by welding to the cathode backscreen on which each cathode is secured to form a comb-like cathode assembly. Further, when the cathode is mounted to the cathode side wall, two or three electroconductive bars extending to the outside of the cell are connected to said current connecting plate. In such case, the part where the electroconductive bar is drawn out is sealed with the asbestos yarn or coal-tar.

The bipolar electrolytic cell of the present invention may seems almost the same as the conventional one described, however, the bipolar cell of the present invention has the metal anode instead of graphite anode and has the novel structure for mounting the electrodes to the partition or the side wall and for electrical connection. According to the present invention, it is easy to renew a diaphragm, repair the electrodes and assemble and disassemble the cell and further, the work for assembling and disassembling can be conducted under good environmental sanitation because the lead welding is not employed. In addition, the electric resistance at the electrical connecting part is sufficiently small and the cell of the present invention can be very precisely assembled, therefore it is possible to shorten the space between the anode and cathode to operate the cell with small voltage loss, and sealing of anolyte between each single cell is sufficiently accomplished, consequently the current efficiency is excellent.

The method of operation is the same as in a conventional diaphragm electrolytic cell but good results are attained. The current capacity is so large as to be equal to that in mercury process cell and the floor space of the cell of the present invention is far smaller than that of mercury process cell and an extremely economical operation can be attained.

With regard to the efficiency, one example of the present invention is given:

EXAMPLE The electrolytic cell is 2050mm outer width, 3500mm length and 1500mm hight and includes five compartments. Each compartment includes 21 of anodes and 20 of cathodes, wherein these electrodes are 875mm hight and 570mm length.

When operating this cell under a current density of 20 A/dm", the current capacity is 200 KA which corresponds to the productive capacity of caustic soda of 200 t./month, and such productive capacity corresponds to ten-time of a conventional bipolar electrolytic cell. The floor space of the above-mentioned cell is 1.06 m /NaOH t /day which corresponds to below one-fourth of that of a conventional bipolar electrolytic cell, therefore the routine work becomes easy and the cost of the equipment becomes cheap.

The voltage loss at the current connecting parts in the bipole unit is ordinarily SOmV or less. Even if the space between the anode and cathode is 10mm, the electrodes can be easily assembled and the space can be further shortened. The cell voltage is such low as 3.4 to 3.6 V in a single cell. The electrolytic results such as the quality of product cannot be absolutely mentioned because they are influenced by not only the cell structure but also the kind of diaphragm and other conditions, however, one example of the results are mentioned for reference: current: 40KA, current capacity: 200 KA, current density: 20 A/dm cell voltage: 3.5 V/single cell, current efficiency: 96 percent, composition of catholyte: NaOH l40g/L, NaClO 0.2g/L, composition of anode gas: C1 98.5%, CO 0.2%, 0 0.6% H 0. 1%.

As above mentioned, the bipolar electrolytic cell of the present invention is the epochal cell which surpasses the conventional diaphragm electrolytic cell.

As many apparently widely different embodiments of the present invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.

What is claimed is:

l. A bipolar diaphragm electrolytic cell assembly, divided into a plurality of single cells as a plurality of bipole units, each of said bipole units having elongated comb-like anodes and cathodes (4, including pectinate anode and cathode hollow portions, a diaphragm on said cathodes, a backscreen (56) having openings, on which said cathodes are connected, a partition (6) with hollow portions having a backplate (65) with openings (63) for securing said anodes, a window (64) for securing said cathode opposite said backplate (65) forming cathodic compartments by combining the hollow portions of said cathodes and said partition, further comprising:

a. an electrode securing means including one or more electroconductive bars (43, 52) disposed in said hollow portions of each anode and each cathode and extending to said partition hollow portion;

b. one or more current connecting plates (8) having connecting openings (81, 82) for connecting to the electroconductive bars of the anodes and cathodes, disposed in said partition hollow portion of each bipole unit, said electroconductive bars (43, 52) of the anodes and cathodes being electrically interconnected to said connecting openings (81, 82) of said current connecting plates, each of said connecting anode openings (81) being so situated as to be opposite to the backscreen (56) between adjacent cathodes;

c. said electroconductive bars of said anodes having a flange (45) for mounting to the back plate (65) and extending through said opening in the backplate and the opening in the current connecting plate (8);

d. said electroconductive bars of said cathodes having a flange (54) for mounting to the backscreen (56) and extending through said opening in the backscreen and the opening in the current connecting plate (8); and,

e. screw means (47, 58) securing said electroconductive bars of said anodes to said backplate and connecting plate, and securing said electroconductive bars of said cathodes to said backscreen and con necting plate.

2. The bipolar diaphragm electrolytic cell defined in claim 1 wherein said screw means securing said electroconductive bars of said anodes comprises nuts and a spiral groove provided to the electroconductive bar of the anode.

3. The bipolar diaphragm electrolytic cell defined in claim 2 wherein the backscreen has openings with removably attached lids, each of said openings with removably attached lids providing access to said nut and being disposed at the point opposite the connecting opening of the current connecting plate for the electroconductive bar of the anode.

4. The bipolar diaphragm electrolytic cell defined in claim 3 wherein said lid has a screw and the electroconductive bar of the anode has an opening therethrough for reception of said screw at the top thereof.

5. The bipolar diaphragm electrolytic cell defined in claim 1 wherein said screw means securing said electroconductive bars of said cathodes comprises a nut and a spiral groove provided to the electroconductive bar of the cathode.

6. The bipolar diaphragm electrolytic cell defined in claim 5 wherein the backplate has openings with removably attached lids, each of said openings with removably attached lids providing access to said nut and being disposed at the point opposite the connecting opening of the current connecting plate with the electroconductive bar of the cathode.

7. The bipolar diaphragm electrolytic cell defined in claim 1 wherein the cell housing is channel-shaped, and the anode side wall and the cathode side wall are connected to said cell housing like a flange to form a boxlike outer shell of the cell.

8. The bipolar diaphragm electrolytic cell defined in claim 7 wherein said cell housing includes guides for vertically mounting and removing the bipole units.

9. The bipolar diaphragm electrolytic cell defined in claim 1 wherein the anodes and cathodes are perpendicular to said partition, and the surfaces of anode are parallel with the opposing surfaces of cathode.

10. A bipolar diaphragm electrolytic cell for electrolytic decomposition of chlor-alkali divided into a plurality of single cells by plural bipole units, each of said bipole units having an elongated comb-like cathode assembly which includes pectinate hollow cathodes and a backscreen to which said cathodes are connected, a diaphragm on said cathodes, elongated pectinate hollow anodes and a hollow partition which has a backplate having openings for fixing said anodes and a window for fixing said cathode assembly at the side opposite said backplate, the cathodic compartments being formed by combining the hollow portions of said cathodes and said partition, which comprises one or more electroconductive bars disposed in said hollow portions of said anode and each cathode respectively and extending to said hollow portion of the partition, and one or more current connecting plates connected mechanically and electrically to said electroconductive bars of cathodes and disposed in said hollow portion of the partition of each bipole unit, said current connecting plate having openings for connecting to the electroconductive bars of the anodes, each of said electroconductive bars of the anodes having a flange for mounting on the backplate and a threaded end and extending through the opening in the backplate and the opening in the current connecting plate and being secured by nuts, the nuts interleaving with the current connecting plate, said backscreen having openings with removably attached lids, each of said openings in the backscreen providing access to a nut disposed at the backscreen side of the current connecting plate and being disposed at the point opposite the connecting point of the current connecting plate with the electroconductive bar of the anode.

l l. The bipolar diaphragm electrolytic cell defined in claim 10 wherein said current connecting plate has openings for connecting to the electroconductive bars of the cathodes, and each of said electroconductive bars of the cathodes has a flange for securing to the current connecting plate and a threaded end and extends through said opening in the current connecting plate and is secured by a nut wherein the backplate has openings with removably attached lids, each of said openings with removably attached lids being disposed at the point opposite the connecting point of the current connecting plate with the electroconductive bar of the cathode and providing access to said nut secured to the electroconductive bar of the cathode.

12. The bipolar diaphragm electrolytic diaphragm cell defined in claim 10 wherein the cell housing is channel-shaped and the anode side wall and the cathode side wall are connected to said cell housing like a channebshaped, and the anode side wall and the cathflange to form a box-like outer shell of the cell. ode side wall are connected to said cell housing like a 13. The bipolar diaphragm electrolytic diaphragm flange to form a box-like outer shell of the cell.

cell defined in claim wherein the cell housing is

Claims

1. A BIPOLAR DIAPHRAM ELECTROLYTIC CELL ASSEMBLY, DIVIDED INTO A PLRALITY OF SINGLE CELLS AS A PLURALITY OF BPOLE UNITS EA CH OF SAID BIPOLE UNITS HAVING ELONGATED COMB-LIKE ANODES AND CATHODES (4,5) INCLUDING PECTINATE ANODE AND CATHODE HOLLOW PORTIONS, A DIAPHRAM ON SAID CATHODES, A BACKSCREEN (56) HAVING OPENINGS, ON WHICH SAID CATHODES ARE CONNECTED, A PARTITION (6) WITH HOLLOW PORTIONS HAVING A BACKPLATE (65) WITH OPENINGS (63) FOR SECURING SAID ANODES, A WINDOW (64) FOR SECURING SAID CATHODE OPPOSITE SAID BACKPLATE (65) FROM ING CATHODIC COMPARTMENTS BY COMBINING THE HOLLOW PORTIONS OF SAID CATHODES AND SAID PARTITION, FURTHER COMPRISING: A. AN ELECTRODE SECURING MEANS INCLUDING ONE OR MORE ELECTROCONDUCTIVE BARS (43), 52) DISPOSED IN SAID HOLLOW PORTIONS OF EACH ANODE AND EACH CATHODE AND EXTENDING TO SAID PARTITION HOLLOW PORTION, B. ONE OR MORE CURRENT CONNECTING PLATES (8) HAVING CONNECTING OPENINGS (81, 82) FOR CONNECTING TO THE ELCTROCONDUCTIVE BARS OF THE ANODES AND CATHODES, DISPOSED IN SAID PARTITION HOLLOW PORTION OF EACH BIPOLE UNIT, SAID ELECTROCONDUCTIVE BARS (43, 52) OF THE ANODES AND CATODES BEING ELECTRICALLY INTERCONNECTED TO SAID CONNECTING OPENINGS (81,82) OF SAID CURRENT CONNECTING PLATES, EACH OF SAID CONNECTING ANODE OPENINGS (81) BEING S SITUATED AS TO BE OPPOSITE TO THE BACKSCREEN (56) BETWEEN ADJACENT CATHODES, C. SAID ELECTROCONDUCTIVE BARS OF SAID ANODES HAVING A FLANGE (45) FOR MOUNTING TO THE BACK PLATE (65 AN EXTENDING THROUGH SAID OPENING IN THE BACKPLATE AND THE OPENING IN THE CURRENT CONNECTING PLATE (8), D. SAID ELETROCONDUCTIVE BARS OF SAID CATHODES HAVING A FLANGE (54) FOR MOUNTING TO THE BACKSCREEN (56) AND EXTENDING THROUGH SAID OPENING IN THE BACKSCREEN AND THE OPENING IN THE CURRENT CONNECTING PLATE (8), AND, E. SCREW MEANS (47,58) SECURING SAID ELECTROCONDUCTIVE BARS OF SAID ANODES TO SAID BACKPLATE AND CONNECTING PLATE, AND SECURING SID ELECTRCONDUCTIVE BARS OF SAID CATHODES TO SAID BACKSCREEN AND CONNECTING PLATE.

7. The bipolar diaphragm electrolytic cell defined in claim 1 wherein the cell housing is channel-shaped, aNd the anode side wall and the cathode side wall are connected to said cell housing like a flange to form a box-like outer shell of the cell.

11. The bipolar diaphragm electrolytic cell defined in claim 10 wherein said current connecting plate has openings for connecting to the electroconductive bars of the cathodes, and each of said electroconductive bars of the cathodes has a flange for securing to the current connecting plate and a threaded end and extends through said opening in the current connecting plate and is secured by a nut wherein the backplate has openings with removably attached lids, each of said openings with removably attached lids being disposed at the point opposite the connecting point of the current connecting plate with the electroconductive bar of the cathode and providing access to said nut secured to the electroconductive bar of the cathode.

12. The bipolar diaphragm electrolytic diaphragm cell defined in claim 10 wherein the cell housing is channel-shaped and the anode side wall and the cathode side wall are connected to said cell housing like a flange to form a box-like outer shell of the cell.

13. The bipolar diaphragm electrolytic diaphragm cell defined in claim 10 wherein the cell housing is channel-shaped, and the anode side wall and the cathode side wall are connected to said cell housing like a flange to form a box-like outer shell of the cell.