IL41397A

IL41397A - Electrolytic cell assemblies and methods for electrolysis

Info

Publication number: IL41397A
Application number: IL41397A
Authority: IL
Original assignee: Diamond Shamrock Corp
Priority date: 1972-01-26
Filing date: 1973-01-25
Publication date: 1976-01-30
Also published as: CA1031293A; JPS4886786A; SE7511155L; DK133541B; DE2303589B2; GB1415984A; FR2169237B1; DE2303589C3; AU5119673A; US3791947A; DE2303589A1; FR2169237A1; DK133541C; IL41397A0; IT977051B; AU473336B2; SE388638B; BR7300596D0; JPS5223633B2

Claims

1. A unit electrolytic cell comprising a cell chambe having side, end and bottom walls, an assembly of electrodes mounted in said chamber in spaced relation to the bottom wall of the .-chamber, and comprising: a plurality of spaced* foraminous parallel substantially horizontally disposed dimensionally stable anodes adapted to receive a plurality of cathodes, a like number of foraminous spaced parallel substantially horizontally disposed cathodes interleaved with said anodes in closely-spaced substantially face- • to-face relation to the anode surfaces, . means for supporting said electrodes in assembled ■ ' - position, means for - supplying electrolyte solution to a space below the lowermost electrode of said assembly, ■ means for supplying electrical current to each anode and withdrawing current from each cathode to thereby apply an electrical potential between said anodes and cathodes to decompose said electrolyte and form decomposition products, at least one of which is gaseous, and means for conducting reaction products from said -e-hsaafe&r chamber.

2. The cell of Claim 1 wherein electrically insulating separators are positioned between adjacent electrode surfaces

3. The cell of Claim 1 wherein the means for supplyin current to each anode and withdrawing current from each cathode consists of at least two current conducting rods, each .

4. The cell of Claim.1 wherein the means for supply ing solution to a point "below the lowermost electrode comprises substantially enclosing the peripheral, edges of the assembly by covering said edges with sheets of electrically non-^conductive material inert to the cell environment.

5. The cell of Claim 1 wherein the means for supply ing solution to a space below the lowermost electrode of the assembly comprises arranging the assembly in the cell chamber s that the peripheral edges of the assembly are enclosed by walls and. partitions adjacent said edges.

6. The cell of Claim.1 wherein the means for supply ing solution to a space below the lowermost electrode of the assembly comprises a solution inlet adapted to supply solution to said space.

7. The cell of Claim 6 wherein the solution inlet is arranged within said space.

8. The cell. of Claim 1 wherein the dimensionally stable anode consists essentially of a valve metal substrate bearing on at least part of its surface a coating of a solid solution of at least one precious metal oxide and at least one valve metal oxide.

9. · The cell of Claim 7 wherein the dimensionally stable anode consists essentially of a titanium metal substrate having a surface coating of a solid solution of titanium dioxid and ruthenium dioxide.

10. The cell of Claim 1 wherein the cathode is constructed of a metal selected from the group consisting of titanium, nickel, steel and stainless steel.

11. The cell of Claim 1 wherein a central wall is positioned intermediate the side walls of the chamber and divides the chamber into a circulation area and an electrode assembly area, a portion of the wall adjacent the bottom wall of the chamber being open to permit circulation of the solution through the entire cell chamber.

12. The cell of Claim 1 wherein the assembly support means comprises at least two pairs of upright substantially parallel support posts, each post being externally threaded at each end and spaced from the other post, said anodes being slidably held by one pair of posts and said cathodes slidably positioned on the other pair of posts in spaced relation, a plurality of substantially parallel spacer bars slidably mounted on each post in substantially horizontal position between the opposed surfaces of the electrodes held by said post, and at least one nut threadably connected to each end of each support post for holding the assembly in fixed rigid position. .

13. An electrolytic cell comprising a cell chamber having side, end and bottom walls provided with at least one inlet and at least one outlet for an electrolyte, at least one assembly of a plurality of substantially parallel foraminous dimensionally stable anodes and a like number of substantially parallel foraminous cathodes, closely-spaced, horizontally disposed and alternately interleaved vertically in substantially parallel face-to-face relationship with said anodes, means for supporting said electrodes in assembled position, means for supplying electrolyte solution to a point below the lowermost electrode of said assembly, means for supplying current to each anode and for withdrawing current from each cathode, said assembl bein s aced from the bottom wall of the chamber. l .

14. A multi-unit electrolytic cell comprising a cell chamber having side, end and bottom walls, means for introducing and means for withdrawing electrolyte solution from the cell chamber, a terminal anode assembly comprising: a plurality of spaced parallel -substantially horizontally disposed foraminous dimensionally stable anodes adapted to receive a plurality of cathodes, means for supporting said anodes in assembled position, means for supplying electric current to the anodes, a terminal cathode assembly comprising a like • number of spaced parallel substantially horizontally disposed foraminous cathodes, means for supporting said cathodes in assembled position, means for withdrawing current from the cathodes a plurality of bipolar electrode assemblies interposed horizontall between said terminal anode and terminal cathode assemblies, means for supporting the bipolar electrodes in assembled position, electrically insulating and substantially liqui sealing partitions separating each bipolar and terminal electrode assembly from horizontally adjacen assemblies, each bipolar electrode extending through each partition, one portion of each bipolar electrode on one side of each partition being a dimensionally stable anode and the other portion of each -bipolar electrode on the other side of each partition being Ν. of the bipolar electrode assembly extending through the partition separating the terminal. anode assembly being cathodes* interleaved with the anodes of said terminal assembly., the portions of the bipolar electrode assembly separating the terminal cathode assembly being dimensionally stable anodes/ the cathodes of said terminal assembly being interleaved with said anodes, all other bipolar electrode portion being interleaved with horizontally, adjacent bipolar electrode portions of opposite polarity.

15. The cell according to Claim 1 wherein the means for supplying solution to a point below the lowermost electrode comprises substantially enclosing the peripheral edges- of the assembly by covering said edges with sheets of electrically non-conductive material inert to the cell environment.

16. The cell according to Claim 1 whe ein the means for supplying solution to a space below the lowermost electrode of the assembly comprises arranging the assembly in the cell chamber so that the peripheral edges of the assembly are enclose by walls and partitions adjacent said edges. I?.

17. The cell according to Claim 1 wherein the means for supplying solution to a space below the lowermost electrode of the assembly comprises a solution inlet adapted to supply solution to said space.

18. The cell according to Claim l^ wherein the solution inlet is arranged within said space.

19. The cell according to Claim l wherein a central wall is positioned intermediate, the side walls of the chamber and divides the chamber into a circulation area and an electrode

20. A process for electrolysis of an aqueous alkali metal halide solution comprising: (a) introducing an aqueous alkali metal halide solution into an electrolytic cell chamber including side, end and bottom -walls, and having disposed therein at least one assembly of a plurality of substantially hori- z'ontally disposed parallel foraminous dimensionally stable anodes adapted to receive a plurality of cathodes, a like. number of spaced substantially horizontally disposed parallel foraminous cathodes, each cathode interleaved with said anodes in closely-spaced substantially parallel face-to-face relation to the anode surfaces, the assembly being spaced from the bottom wall of said chamber, (b) passing a direct current between the the anodes and cathodes to electrolyze and decompose the alkali metal halide solution, . (c) during the electrolysis the temperature of the alkali metal halide solution- being maintained at about 15°C to about 0°C. and the pH of the solution ranging from about 6.0 to about 10.0. (d) causing electrolyte to circulate to a space below the lowermost electrode of the assembly and then flow upwardly from said space through all the electrodes of the assembly by the lift effect of the gases generated at the foraminous electrodes during electrolysis, and

21. The process according to Claim 20 wherein 'the peripheral edges of the assembly are at least partially enclosed and cause the electrolyte to circulate to the space below the lowermost electrode.

22. The process according to Claim 20 wherein the peripheral edges of the assembly are* substantially completely enclosed and cause -the electrolyte to circulate to the space below the lowermost electrode.

23. The process according to Claim 20 wherein an aqueous solution containing about 315 ' rams' per liter of sodium chloride and about 2.0 grams per liter of sodium dichromate is introduced to the cell, the temperature is maintained at about k °C. to about 8o°C, the pH is maintained at about 6.0 to about 1. » and sodium chlorate is recovered from the cell chambe II .

24. The process according to Claim 20 wherein an aqueous solution containing from about 25 to 30 grams per liter of sodium chloride, is introduced into the cell chamber, the temperature is maintained at about 20°C. to about 25°C, the pH ranges from about 8.5 to about 9· 2 and sodium hypochlorite is recovered from the cell chamber.-

25. An electrolytic process comprising: (a) introducing a solution which releases at least one gaseous product at an electrode surface when electrolyzed into an electrolytic cell chamber, including side, end and bottom walls, and having disposed therein at least one assembly of a plurality of horizontally disposed parallel foraminous ' dimensionally stable anodes adapted to receive a plurality of cathodes, a plurality of substantially · horizontall dis osed arallel foraminous cathodes d odes eeous om y,