Apparatus for the Production by Electrolysis of Chlorine and Alkalies.
Year: 1892

page_text: Date of Application, 17th May, 1892
Complete Specification Left, 23rd May, 1892-Accepted, 16th July, 1892
PROVISIONAL SPECIFICATION.
Apparatus for the Production by Electrolysis of Chlorine and
Alkalies.
I, CARL KELLNER of 1X Turkenstrasse 17, Vienna, Austria, Chemist do.
hereby declare the nature of this invention to be as follows:-
The production of bleaching agents and alkalies from chlorine-containing com-
pounds is most simply effected by means of electrolysis. Heretofore however it
has not been possible to utilize this method of production on an industrial scale.
All the apparatus heretofore proposed, for instance for producing chlorine and
caustic soda by electrolytically decomposing common salt, are not suited for use
on a large scale for the following reasons:-
1. The decomposing apparatus are costly and complicated, and do not sufficiently
resist the action of chlorine and caustic soda;
2. The electrodes, and in particular the anodes, as also the diaphragms, are
destroyed so quickly, that the cost of repairs and renewal of the decomposing
apparatus is prohibitive;
3. At a certain point of the decomposing operation, diffusion takes place, which
by the formation of hypochlorite and chlorate, has a very unfavourable effect on the
output and on the consumption of electrical energy.
The present invention has for its object to obviate the aforesaid drawbacks, by
the peculiar construction and by the special selection of the material of which the
decomposing apparatus is constructed.
The accompanying drawings illustrate a decomposing apparatus according to this
invention.
Fig. 1 illustrates partly in vertical section and partly in elevation, one of the
decomposing cells of such apparatus.
Fig. 2 is a vertical cross section on the line - of Fig. 1.
Fig. 3 is a plan partly in horizontal section on the line of Fig. 1, and
Fig. 4 is a section through one of the anodes.
Figs. 5, 6 and 7 show in vertical longitudinal section, plan and cross sectional
elevation respectively, a modified form of a decomposing cell with rotating disc-
shaped cathodes.
Figs. 8 and 9 illustrate in longitudinal section and cross section respectively, an
arrangement of the decomposing cells suitable for producing the alkali in the form
of carbonate.
Figs. 10 and 11, and Figs. 12 and 13 are respectively a plan partly in hori-
zontal section and a vertical cross section of two modifications of these decomposing
cells.
As shown in Figs. 1, 2 and 3, the cells of the decomposing apparatus in which
the electrolytical decomposition of the solution takes place, consist of a cast iron
trough having cast on one of its side walls, partitions 6 which terminate as shown
at some distance from the opposite side wall. The said trough or said partitions b
constitute the cathodes, and into the intermediate spaces there are arranged frames c
of suitable acid-resisting and alkali-resisting material, such for examples as stoneware
and glass (hard glass) containing the anodes d and diaphragms f.

page_text: The entire space between the diaphragms, is filled with powdered carbon in
which are inserted the carbon rods or plates d serving as anodes to conduct the
current. As the powdered carbon conducts the current to a certain extent, the
chief action, that is to say, especially the production of gas which destroys
the anodes so quickly, does not take place as heretofore at the surface of the
carbon rods or plates d that conduct the current, but chiefly in the adjacent
powdered carbon, whereby the anodes are rendered practically indestructible.
This construction of anodes, as it were of a conducting powder, has, in addition
to the indestructibility of the same, the further advantage that diffusion is entirely
prevented, because the anode spaces contain no other liquid than that which is
absorbed and retained by the powdered carbon.
"
As will be readily understood the separated chlorine passes by "the travel of the
ions to the anode, whereby the additional advantage is obtained that a decom-
position of water by the liberated chlorine which otherwise takes place when aqueous
solutions are employed in the anode space, is obviated.
In order that the diaphragms may be made as indestructible as the cathodes and
anodes, they are made of plates of slate or glass, or of plates of ceramic materials,
which, where they dip into the liquid, are formed with holes in such a manner that
on placing two such plates opposite each other, the holes in one plate will be situated
opposite the solid portions of the other plate.
Between each pair of such plates ff at each side of the space y, there is inserted
a layer of material such as glass-wool, asbestos, nitro-cellulose or paper stuff, the
two plates being inserted into grooves in the frame c, and the intermediate spaces
thus formed are filled with powdered carbon or, when decomposing a solution of
common salt, with solid common salt.
Diaphragms thus constructed conduct the current very well, can be cheaply made,
and prevent all mechanical diffusion.
In this manner the anode and the diaphragms form with the frame c, a closed
vessel or cell which is inserted into the trough in such a manner that it is close
against that longitudinal wall of the trough which is not touched by the partitions
(cathodes), and that said cell does not touch the longitudinal wall from which the
cathodes extend.
In consequence of this arrangement a zig-zag path is provided for the electrolyte,
so that every particle of liquid entering the apparatus is compelled to pass along
the entire length of the cathode and of the diaphragms, and a sufficient flow or
circulation is produced whereby the hydrogen is removed from the cathode without
the employment of complicated pipe conduits.
If the alkali is to be produced in the form of carbonate, instead of caustic alkali,
the anode frames of the apparatus described, are simply placed at a higher level,
as shown in Figs. 8 and 9, and carbonic acid is blown through a pipe into the
saturated solution of common salt which fills the trough. The alkaline carbonate
formed is insoluble in a saturated solution of common salt, and it is therefore
precipitated in the form of small crystals in the space beneath the anode frames,
whence it is removed. Fresh brine is constantly allowed to flow into the cathode
spaces where it becomes saturated with the salt from between the diaphragms
which salt must also be renewed from time to time. It is in this case therefore
advantageous to introduce the added brine directly into the central space between
the diaphragms.
If the apparatus described is to be used for liberating chlorine from compounds
the cation of which separates in solid form, such for example as the calcium chloride
obtained as residual product in the manufacture of soda by the ammonia-soda
process, or the magnesium chloride obtained in the Stassfurt industry, the cathodes
of the apparatus are made in the form of rotating discs b, as shown in Figs. 5, 6
and 7, to which the electric current is supplied by means of brushes arranged to bear
upon the common shaft b¹.
If in such an apparatus chlorine is to be produced from hydrochloric acid, the
cathodes are made of lead instead of iron.

page_text: Figs. 10 and 11 show a modified construction of the decomposing cells in which'
the liquid enters the cell formed by the frame, anode, and diaphragms, at one
narrow side, and after it has flowed over the whole surface of the electrodes, it passes
out again at the same narrow side.
Figs. 12 and 13 show a further modified construction in which the inlet and outlet.
openings on the same side of the frame are connected together to form a continuous
channel
77b9 in which the anode liquid takes a zig-zag course and thus circulates as a
counter current to the cathode liquid. In this arrangement the channel m may be
covered over by a gas bell n, for the purpose of collecting and conveying away the
gas generated.
1000
CARL KELLNER,
By L. W., per F. B.
COMPLETE SPECIFICATION.
Apparatus for the Production by Electrolysis of Chlorine and
Alkalies.
I, CARL KELLNER of 1X Turkenstrasse 17, Vienna, Austria, Chemist, do
hereby declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:-
The production of bleaching agents and alkalies from chlorine-containing
compounds is most simply effected by means of electrolysis. Heretofore however
it has not been possible to utilize this method of production on any industrial scale.
All the apparatus heretofore proposed, for instance for producing chlorine and
caustic soda by electrolytically decomposing common salt, are not suited for use on
a large scale for the following reasons:-
1. The decomposing apparatus are costly and complicated, and do not sufficiently
resist the action of chlorine and caustic soda;
2. The electrodes, and in particular the anodes, as also the diaphragms, are
destroyed so quickly, that the cost of repairs and renewal of the decomposing
apparatus is prohibitive.
The present invention has for its object to obviate the aforesaid drawbacks, by
the peculiar construction and by the special selection of the material of which the
decomposing apparatus is constructed.
Referring to the drawings left with my Provisional Specification which illustrate
a decomposing apparatus according to this invention,
Fig. illustrates partly in vertical section and partly in elevation, one of the
decomposing cells of such apparatus ;
Fig. 2 is a vertical cross section on the line x-x of Fig. 1;
Fig. 3 is a plan partly in horizontal section on the line - of Fig. 1; and
Fig. 4 is a section through one of the anodes.
Figs. 5, 6 and 7 show in vertical longitudinal section, plan and cross sectional
elevation respectively, a modified form of a decomposing cell with rotating disc-
shaped cathodes.
Figs. 8 and 9 illustrate in longitudinal section and cross section respectively, an
arrangement of the decomposing cells suitable for producing the alkali in the form
of carbonate.
Figs. 10 and 11, and Figs. 12 and 13 are respectively a plan partly in horizontal
section and a vertical cross section of two modifications of these decomposing cells.
As shown in Figs. 1, 2, and 3, the cells of the decomposing apparatus in which
the electrolytical decomposition of the solution takes place, consist of a cast iron
trough having cast on one of its side walls, partitions which terminate as shown
at some distance from the opposite side wall. The said trough or said partitions
constitute the cathodes, and into the intermediate spaces there are arranged

page_text: frames c of suitable acid-resisting and alkali-resisting material, such for examples
as stoneware and glass (hardened glass) containing the anodes d and diaphragmsf.
The entire space g between the diaphragms, is filled with powdered carbon in
which are inserted the carbon rods or plates d serving as anodes to conduct the
current. As the powdered carbon conducts the current to a certain extent, the
chief action, that is to say, especially the production of gas which destroys
the anodes so quickly, does not take place as heretofore at the surface of the carbon
rods or plates d that conduct the current, but chiefly in the adjacent powdered
carbon, whereby the anodes are rendered practically indestructible.
This construction of anodes, as it were of a conducting powder, has, in addition
to the indestructibility of the same, the further advantage that diffusion is entirely
prevented, because the anode spaces contain no other liquid than that which is
absorbed and retained by the powdered carbon.
As will be readily understood the separated chlorine passed by "the travel of
the ions" to the anode, whereby the additional advantage is obtained that a
decomposition of water by the liberated chlorine which otherwise takes place when
aqueous solutions are employed in the anode space, is obviated.
In order that the diaphragms may be made as indestructible as the cathodes and
anodes, they are made of plates of slate or glass, or of plates of ceramic materials,
which, where they dip into the liquid, are formed with holes in such a manner that
on placing two such plates opposite each other, the holes in one plate will be
situated opposite the solid portions of the other plate.
Between each pair of such plates ff at each side of the space g, there is inserted
a layer k of material such as glass-wool, asbestos, nitro-cellulose or paper stuff, the
two plates being inserted into grooves in the frame c, and the intermediate spaces
thus formed are filled with powdered carbon or, when decomposing a solution of
common salt, with solid common salt.
Diaphragms thus constructed conduct the current very well, can be cheaply
made, and prevent all mechanical diffusion.
In this manner the anode and the diaphragms form with the frame c, a closed
vessel or cell which is inserted into the trough in such a manner that it is close
against that longitudinal wall of the trough which is not touched by the partitions
(cathodes) and that said cell does not touch the longitudinal wall from which the
cathodes extend.
In consequence of this arrangement a zig-zag path is provided for the electrolyte,
so that every particle of liquid entering the apparatus is compelled to pass along
the entire length of the cathode and of the diaphragms, and a sufficient flow or
circulation is produced whereby the hydrogen is removed from the cathodes without
the employment of complicated pipe conduits.
If the alkali is to be produced in the form of carbonate, instead of caustic alkali,
the anode frames c of the apparatus described, are simply placed at a higher level,
as shown in Figs. 8 and 9, and carbonic acid is blown through a pipe 7 into the
saturated solution of common salt which fills the trough. The alkaline carbonate
formed is insoluble in a saturated solution of common salt, and it is therefore
precipitated in the form of small crystals in the space beneath the anode frames,
whence it is removed. Fresh brine is constantly allowed to flow through the pipe
into the cathode spaces where it becomes saturated with the salt from between the
diaphragms which salt must also be renewed from time to time. It is in this case
therefore advantageous to introduce the added brine directly into the space
between the diaphragms containing the salt solution.
If the apparatus described is to be used for liberating chlorine from compounds
the cation of which separates in solid form, such for example as the calcium
chloride obtained as residual product in the manufacture of soda by the ammonia-
Boda process, or the magnesium chloride obtained in the Stassfurt industry, the
cathodes of the apparatus are made in the form of rotating discs b, as shown in
Figs. 56 and 7, to which the electric current is supplied by means of brushes
arranged to bear upon the common shaft b'.

page_text: If in such an apparatus chlorine is to be produced from hydrochloric acid, the
cathodes are made of lead instead of iron.
Figs. 10 and 11 show a modified construction of the decomposing cells in which
the liquid enters the cell formed by the frame, anode and diaphragms, at one
narrow side, and after .it has flowed over the whole surface of the electrodes, it.
passes out again at the same narrow side.
Figs. 12 and 13 show a further modified construction in which the inlet and
outlet openings on the same side of the frame are connected together to form a
continuous channel m in which the anode liquid takes a zig-zag course and thus
circulates as a counter current to the cathode liquid. In this arrangement the
channel m may be covered over by a gas bell n, for the purpose of collecting and
conveying away the gas generated.
Having now particularly described and ascertained the nature of the inven-
tion and in what manner the same is to be performed, I declare that I am aware
that it has been proposed to supply carbonic acid to electrolytic apparatus for the
production of chlorine and alkalies, in order to decompose the hydrate as soon as
formed and produce carbonate, I therefore make no claim for supplying carbonic
acid except to my improved apparatus, but what I claim is :-
1. Apparatus for the electrolytical production of chlorine and alkalies, com-
prising a number of decomposing cells connected in parallel or in series and each of
which is provided with cathodes consisting of fixed or rotating walls between which
frames of acid-proof and alkali-proof material containing the anodes and diaphragms
are inserted in such a manner that the electrolyte is compelled to take the longest
path in the cathode spaces, whilst the anode spaces act by "travel of the ions,"
substantially as described.
"
2. In decomposing apparatus of the kind referred to in the preceding claim, the
arrangement of the anodes which are surrounded with powdered carbon for the
purpose of increasing their durability, and of the diaphragms located at both sides
of each anode and consisting of perforated plates of slate, glass, or ceramic material
with an intermediate layer of material such as glass-wool, asbestos, nitro-cellulose
or paper stuff, forming a porous membrane, within frames of resisting material such
as stoneware or glass, which are inserted between the cathodes of iron or lead in
such a manner that the electrolyte is compelled to take a zig-zag course between
the cathode frames and the anode frames substantially as described.
3. In decomposing apparatus of the kind specified in Claim 1, the arrangement
within a frame of stoneware or glass, of electrodes which are shut off on both sides
by diaphragms in such a manner that they form a cell which is inserted between
the dissimilarly named electrodes, substantially as described.
4. In decomposing apparatus of the kind referred to in Claim 1, the arrangement
of the anodes within powdered carbon substantially as described.
5. In decomposing apparatus of the kind specified in Claim 1, the arrangement
of diaphragms consisting of perforated plates of resisting material, such as slate,
ceramic material, or glass, particularly hardened glass, between which the mass
of material forming the porous membrane proper, is located, substantially as
described.
6. In the construction of diaphragms referred to in the preceding claim, the
employment of glass-wool as a membrane, substantially as described.
7. In decomposing apparatus of the kind specified in Claim 1, the use as a
diaphragm, of a layer of powdered carbon or of a salt identical with that contained
in the electrolyte, substantially as described.
8. Apparatus such as specified in Claim 1, comprising a trough forming the
cathodes b, and frames inserted between the cathodes with the anodes d and the
diaphragms, the several parts being constructed and arranged substantially as
herein before described with reference to and shown in Figs. 1 to 4 inclusive of the
drawings.
9. In the apparatus specified in Claim 8, the employment of grooved frames c

page_text: into which the electrodes d are inserted between the diaphragms f which are
inserted in the said grooves, substantially as described.
10. In the apparatus spécified in Claim 8, the arrangement of rotating cathodes b
between the frames c containing the anodes and diaphragms, substantially as
hereinbefore described with reference to and shown in Figs. 5 to 7 inclusive of the
-drawings.
11. In the apparatus specified in Claim 1, the arrangement of the pipe! under
the anode frames c for the purpose of introducing carbonic acid, substantially as
-described with reference to and shown in Figs. 8 and 9 of the drawings.
Dated this 23rd day of May 1892.
C. KELLNER,
By L. W., per F. B.