Improvements in Electrodes.
Year: 1894

page_text: Date of Application, 5th June, 1894
Complete Specification Left, 5th Apr., 1895-Accepted, 4th May, 1895
Improvements in Electrodes.
I, CARL HOEPFNER, of 36 Frankfurterstrasse, Giessen, in the Empire of
Germany, Doctor of Philosophy, do hereby declare the nature of this invention to
be as follows:-
The difficulties encountered in obtaining carbon electrodes of great superficial
area are well understood, in fact, it has been impossible to produce retort carbon
electrodes of great superficial area, and it has been attempted to overcome this
difficulty by constructing the electrodes of artificial carbon or carbon paste.
These electrodes however are costly and not very durable when exposed to certain
chemical agents, and they are also liable to injury.
My invention has for its object to overcome this difficulty by the provision of
means whereby carbon electrodes (either retort or artificial) having any desired
extent of active surface may be constructed at a comparatively low cost.
In certain electrolytical processes it has been found of the greatest advantage
to employ movable cathodes. I have discovered that certain electrolytical
processes can be carried out with greater advantage when both cathodes and
anodes are kept in motion, as for instance in the electrolytical production of zinc,
nickel and other metals from their solutions, especially chloride solutions.
My invention has also for its object to so construct the electrodes that both
cathode and anode can be kept in motion. Further my invention has for its object
the use of these electrodes in electrolytical apparatus or in generators of
electricity.
The essential feature of invention in the electrodes consists in so constructing
the same that any desired active or conductive surface can be obtained with as
small pieces of carbon as possible, and this result can be obtained in various ways.
The electrode is mostly constructed of a frame of wood, which for certain
electrolytical processes may be nitrated, said frame being grooved interiorly to
receive a non-conductive or acid proof plate of any suitable material, as wood,
rubber, celluloid, vulcanized fibre, glass, asphaltum, or the like, said plate having
numerous perforations for the reception of carbon rods that project from the
opposite faces of said plate.
This plate may be obtained also by placing the loose carbon rods or pieces into
the frame and connecting them afterwards tightly by cement, asphaltum or the
like.
It is obvious that by means of the described construction I obtain an electrode
one face of which serves as an anode and the other as a cathode, and that com-
paratively small bodies of carbon can be used in its construction and an electrode
obtained having an active surface of any desired area, and the cost of which is
comparatively low as compared with that of an electrode of like dimensions con-
structed wholly of carbon. Instead of carbon rods, carbon tubes may be employed
under certain circumstances and be filled with an active agent, or said active agent
may be inserted between the carbon rods as well as between the carbon tubes, or
aid carbon tubes may be kept impregnated with chlorine or an oxidizing or other
reducing agent.
In some electrolytical processes it may be found advantageous to substitute a
netal plate, as a plate of copper, for instance, for the acid proof plate, in which
ase one face of the plate is insulated by means of any suitable material, as rubber.

page_text: or asphaltum, while in other electrolytical processes it may be of advantage to
sheath the carbon rod in metal, as zinc, for instance.
These electrodes may be assembled between head plates, each provided with a
journal, thus forming alternate anode. and cathode cells, the said journals being
included in the circuit of an electric generator, and respectively connected with
conductor, as a suitable metallic plate, said plate being clamped between the en
electrodes and the head plates.
It will readily be seen that an electrode constructed as described may receive
a rotary or an oscillating motion, both anodes and cathodes partaking of such
motion.
:
In certain electrolytical processes it may become necessary to separate the
electrodes by diaphragms this may readily be effected by interposing such
diaphragms between the electrodes; furthermore, it may be found advantageous,
to increase the cross sectional area of the cells, which can readily be done by inter-
posing one or more frames, between each two electrodes. It is further evident
that by interposing a metallic diaphragm between two electrodes and using suitable
exciting agent, the apparatus can be used for generating instead of consuming.
electricity. The several cells of an electrolytical apparatus may be supplied with
an electrolyte from a common channel by forming a through passage in the frames
and passages leading therefrom to the opposite sides of the carbon holder or
carbons, and the electrolyte may be caused to flow out of the cells through similar
passages when the apparatus is stationary with a view to a continuous operation.
Or the passage may be so arranged as to connect all the anode cells and all the
cathode cells separately in series, or the arrangement may be such as to cause the
electrolyte to How from one cell to another. All these arrangements are well
known, and their selection depends upon the uses made of the apparatus.
It is obvious also that the cells may be isolated from one another and a different
electrolytical process carried out in each of them, also that the cathode cells as well
as the anode cells may be supplied with solid substances to be reduced or oxidized
or dissolved, as for instance, sulphides, peroxides or oxides, as oxide of manganese
or of nickel, or metals or sulphides.
Finally by means of the electrodes constructed as described an electrolytical
apparatus may be stationary, revoluble, or vibratory, and may be arranged with its
major axis in an horizontal oblique or vertical plane.
Dated this 5th day of June 1894.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in Electrodes.
I, Dr. CARL HOEPPNER, of 36 Frankfurterstrasse, Giessen, in the Empire of
Germany, Chemical Electrician, 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 difficulty encountered in obtaining durable carbon electrodes of great
superficial area are well understood, in fact, it has been impossible to produce
retort carbon electrodes of great superficial area.
Attempts have been made to overcome this difficulty by constructing the
electrodes of artificial carbon or carbon paste. These electrodes however are costly
and not very durable when exposed to eléctrolytic action or to certain chemical
agents, and they are also liable to injury.
My invention has for its object to overcome this difficulty by the provision of
means whereby carbon electrodes (either retort or artificial) having any desired.

page_text: extent of active surface may be constructed at a comparatively low cost, such
electrodes being mostly intended to be used as double electrodes one face of which
serves as an anode and the other as a cathode.
In certain electrolytical, especially in metallurgical processes which are of the
greatest importance, it has also been found of great advantage to employ movable
cathodes. I have discovered that certain electrolytical processes can easily be
carried out with such double electrodes and the more advantageously when both
cathodes and anodes are kept in motion, as for instance in the electrolytical pro-
duction of zinc, nickel and other metals from their solutions, especially chlorine
solutions.
It is very difficult to make both cathodes and insoluble anodes movable in common
electrolytical apparatus.
A further object of my invention therefore is to so construct the said double
electrodes that both cathode and anode can be kept in motion.
Considering that double electrode apparatus do away with so many electrical
connections this can simply be done by moving (rotating or vibrating) the
electrodes or the electric apparatus itself as a whole constructed by means of
such double electrodes as hereinafter more fully described.
Another object of my invention consists in employment of these electrodes in
electrolytical (preferably electro-metallurgical) apparatus ⚫ or generators
electricity.
of
The essential feature of my invention concerning these electrodes consists in so
constructing the same that any desired active carbon surface can be obtained with
small pieces of carbon and that these electrodes can be employed as double
electrodes. This result can be obtained in various ways as hereinafter described.
In the following description and claims by active face or side should be
understood the anode face in electrolytical and the positive pole in electric
generators. It should also be stated that the signification "cathode" relates to
the employment of the double electrodes of the present invention for electrolytical
processes and that for the employment of these electrodes for electro-motive
purposes the term "anode" instead of "cathode is to be understood.
In the accompanying drawings
23
Figure 1 represents an elevation of the improved electrode.
Figure 1 is a section of one form of the electrode.
Figure 2 is an elevation of another form.
Figure 3 shows one way of holding the carbon rods.
Figure 3 shows the manner of fixing the pieces of carbon to the non conductive
plate.
Figure 4 is a section showing a number of double electrodes arranged to form a
battery.
Figure 5 shows part of a battery with double electrodes.
Figure 6 shows the electrode arranged in an electrolytic vessel.
Figure 7 is a view showing the carbon rod provided with a sheath or covering.
Figure 8 is a section of a plate showing the use of carbon tubes instead of rods.
Figure 9 is a further modification of the plate with the carbon pieces attached
thereto.
The electrode is chiefly constructed of a frame of wood F, Figures 1, 1 and 2,
which for certain electrolytical processes may be nitrated the said frame being
conveniently grooved interiorly to receive a non-conductive or acid proof plate P
of any suitable material, such as wood, rubber (hard rubber, ebonite, vulcauite),
celluloid, vulcanized fibre, cloth, glass, asphaltum or the like the said plate having
umerous perforations for the reception of rods or pieces of carbon C that project
from one or both faces of the said plate. Care must be taken that direct com-
munication of the liquids from one face to the other through the plate is prevented,
for instance in case porous plates, like cloth, are to be used.
Such an impermeable plate may be obtained also by placing the loose carbon
rods or pieces in the frame and connecting them afterwards by cement, asph. Itum

page_text: or by any other binding or connecting means, whereby the carbon surface may
project only from one of the faces.
The cathode side in electrolytical apparatus as well as the positive sides in
electric generators is conveniently or naturally covered by metals and of course need
not be enlarged whilst the opposite active carbon faces are the more effective the
larger their superficial area is. Therefore the carbon rods or pieces C.need not
project but from one face of the plate P Figures 3 and 3^. In this case the carbon
pieces are inserted in the perforations-as-shown for instance by Figure 3, so as to
not project from the one side of the plate P or the said pieces may be fitted upon
one face of the said plate, for instance by means of a binding agent K Figure 3*
such as cement, asphaltum or the like. The plate which may be a simple plate or
in large apparatus composed of several plates or layers or the like may also be
porous or gauze-like, for instance it may consist of cloth or the like in or upon
which the carbon pieces of any suitable shape may be arranged or fitted. The
carbon pieces C which may be so formed as to have on their active side a possibly
large surface, may be also employed in the form of tubes C' Figure 8, which, as
hereinafter described for electrolytical or metallurgical purposes, may be filled with
an active agent as for example minerals as shown at E in Figure 8, or the said
active agent may be inserted between the carbon rods or tubes, or (especially for
the generation of electricity) the said carbon tubes may be kept impregnated with
chlorine or an oxidizing or another or reducing agent.
In electrometallurgical processes it may be found advantageous to substitute for
the acid proof plate a metal plate P1, Figure 8 (which may be a simple or in large
apparatus compound plate or which may be perforated, porous or impermeable,
gauze-like or consisting of network or the like) as a plate of copper, for instance
in which case its face on the active side of the plate or of the compound plate, or of
the system of plates, may be insulated by means of any suitable material R,
Figure 8, such as rubber or asphaltum.
The carbon pieces C may then also be fitted upon the metallic plate PI in a similar
manner to that shown in Figure 34 relating to plate P of other material.
It is necessary to provide means to render detachable the metal to be deposited
on the cathode in electrolytical apparatus and to render attachable the metal to be
dissolved in electric generators. For this purpose the cathode side is conveniently
covered, with a coherent metallic plate P1 Figure 9 and caused to be in close
connection with it by metallic deposition. With this connecting plate a second
plate P2, Figure 9 is then conveniently brought into contact, so as to cover it.
This second plate is detachable and can be easily replaced by another as soon as
a desired quantity of metal has been deposited thereon.
For the same purpose it may also be advantageous to sheath or to cover the
carbon rods C, Figure 7 if projecting on the cathode side in or with metallic caps Z,
for instance of zinc.
It is obvious that by means of the herein described construction I may obtain an
electrode one face of which serves as an anode and the other as a cathode and that
comparatively small cheap pieces of carbon can be used in its construction and an
electrode obtained having an active surface as large as desired but independent of
the space between the circumference of such electrode, and the cost of which is
comparatively low as compared with that of a common electrode of like dimensions
consisting wholly of carbon.
The shape of the carbon pieces especially on the active side, may be varied
at will.
These double electrodes may be arranged so as to form a battery, in which they
may be connected in parallel circuit or in series and the said double electrodes may
be pressed together between end plates p p', Figure 4 like a filter press, for instance
by means of screws so as to obtain a battery having alternately cathode and anode.
Said end plates may each be provided with a journal J J' which are each electrically
connected with a conductor placed on the inner side of the end plates, such as with
suita! le metallic or carbon plate or rods 2 or 3, and which moreover are included

page_text: in the circuit of a source of electricity such as a dynamo, or in any desired
circuit.
In case the double electrodes are connected in parallel circuit alternate 'metallic
anodes and cathodes must be interposed between said double electrodes. The
metallic anodes can then be made to grow together with the cathode sides of the
double electrodes by electro-metallic deposition.
It is obvious that the connections can partially also be made between any of the
pairs of double electrodes so as to develop a mixed system of connection in parallel
circuit and in series. It will readily be seen that double electrodes constructed and
arranged as described may receive a rotary or an oscillating motion, buth anodes
and cathodes partaking of such motion.
It is obvious that the apparatus can also be kept in rotation by means of rolls or
any other suitable contrivance.
If desired the double electrodes, connected in parallel circuit or in series, may be
separated by diaphragms D, Figure 4; this may readily be effected by interposing
such diaphragins between the electrodes or frames; furthermore, it may be found
advantageous, to increase the cross sectional area of the cells, which can readily be
done by interposing one or more frames f, f, Figure 4 between each two
electrodes.
It is further evident that by interposing a metallic diaphragm, D1, Figure 5,
which figure shows in section a part of an electric generator with double electrodes
according to the present invention, or a metallic plate between two electrodes and
using a suitable exciting agent, the apparatus (in which the double electrodes may
be connected in parallel circuit or in series) can be used for different electrolytical
purposes and also for furnishing a supply of electricity.
The cells of an electrolytical apparatus composed of such electrodes or part of
them can indeed be used for generating instead of consuming electricity. The
several cells of an electrolytical apparatus may be supplied with an electrolyte
from a common channel by forming a through passage 4, Figure 1 in the frames
and passages 5, 6, Figure 1 leading therefrom to the opposite sides of the carbon
holders or carbons, and the electrolyte may be caused to flow out of the cells
through similar passages when the apparatus is stationary with the object of causing
a continuous operation. Or the passage may be so arranged as to connect all the
anode cells and all the cathode cells separately in series, or the arrangement may
be such as to cause the electrolyte to flow from one cell to another or the
electrode-apparatus may be arranged within the electrolyte vessel (Figure 6).
All these arrangements are well known, and their selection depends upon the uses
made of the apparatus.
It is obvious also that the cells may be chemically isolated from one another and
a different electrolytical process carried out in each of them, also that the cathode
cells as well as the anode cells may be supplied with solid substances to he oxidized
or dissolved or reduced, as for instance metals, sulphides of heavy or light metals or
oxides, as oxide of manganese or the like.
By means of the double electrodes constructed as herein described an electro-
lytical apparatus may be stationary or movable (revoluble or vibratory) and may
be arranged with its major axis in an horizontal, oblique or vertical plane.
The merit of being movable as a whole or having movable anodes enables such
apparatus to be advantageously used for electrolytical or electrometallurgical
purposes and for the direct oxidizing or reducing treatment of minerals or other
substances in a powdered state to be filled in the cells as well as for the like
treatment of gaseous matters, such as sulphurous acid or of organic matters (as
acetylene); the passages described enable a constant feeding of the apparatus which
can be kept full or only partly full whenever gases must be present in it such as
chlorine to be used for generation of electricity.
If such apparatus with movable double electrodes or movable itself is to be used
for generation of electricity, salts, acids or gases like oxygen, chlorine, are easily
supplied and caused to act upon metals and sulphides.

page_text: The supply of depolarizing matter can of course be effected constantly or
interruptedly.
Having now particularly described and ascertained the nature of my said inver-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. A double electrode comprising anode and cathode for electrometallurgical
apparatus or electric generators substantially as described.
2. A double electrode consisting of a series or a group of carbon bodies set in a
framing so as to present carbon surfaces on opposite sides of said framing tightly
connected with each other by some acid proof or other material, which opposite
carbon surfaces however differ so that one of them corresponding to the anode sides
in electrolytical apparatus or corresponding to the negative pole in electric
generators is conveniently enlarged whilst the opposite one may conveniently be
Covered with metal so as to render detachable the metal which is to be deposited
electrolytically and to make attachable the metal which is to be dissolved in electric
generators..
3. A double electrode consisting of a perforated porous plate or similar material
or a system of perforated or porous plates or similar material as for instance cloth,
carbon rods or pieces secured in or on the latter so as to project from one or both
sides of the plate or plates and suitable framing for said plate or plates for the
purpose set forth.
4. A double electrode consisting of a perforated or porous plate or system of
plates or similar material, tubular carbons secured in or on the latter so as to
project from one or both faces of the plate or plates and if convenient a framing
for said plate or plates for the purpose set forth.
5. A double electrode consisting of a perforated plate or a system of plates or
similar material, carbon rods secured in or on the latter so as to project from one or
both the opposite faces of said plate or plates if convenient a framing for the
latter and carbon or active agent or minerals applied in the spaces between the
projecting carbons or inside the carbons themselves for the purpose set forth.
6. A double electrode consisting of a perforated plate or plates of metal or a
wire-net, having one of its faces insulated carbon rods or pieces secured in or on the
perforations so as to project from one or both faces of said plate or plates and if
convenient a framing for the latter, for the purpose set forth.
7. In an electric or electrometallurgical apparatus a series of double electrodes
as described for instance in Claims 1 and 2 or consisting of a framed porous or
perforated plate or system of plates or similar material, such as cloth and carbon
rods or pieces secured in or on the latter and projecting from one or both faces of
said plate in combination with two or more end plates, each provided with a
conducting plate interposed between each end plate and the adjacent double
electrode, said conducting plates being electrically connected with the poles of the
circuit for the purpose set forth.
8. The combination with a series of double clectrodes comprising double electrodes
as described in Claims 1 and 2 or a framed porous or perforated plate or system of
plates or similar material and carbon rods or pieces secured in or on them and
projecting from one or both the opposite faces of said plate or plates, of conducting
plates, as for instance plates of copper interposed between two double electrodes,
for the purpose set forth, and also for the use of double electrodes in electric
batteries with electrodes connected in parallel circuit or in series.
9. An electrical apparatus containing movable (rotary or vibratory) double
electrodes or movable itself as a whole.
10. An electrical apparatus containing movable double electrodes or movable
itself for the purpose of treating electrolytically at the electrodes: (a) minerals in
a powdered state (b) gaseous matters (c) organic matters provided with pipes or
conductors to enable a constant or interrupted feed ng of the apparatus, which can
be kept full or partly full whenever gases must be present in it.

page_text: 11. An electrical apparatus containing movable double electrodes or movable
itself for the purpose of galvanic production of electricity by the action of salts or
acids and gases like oxygen, chlorine on metals and sulphides so as to enable
constant or interrupted supply of depolarising matter.
Dated this 5th day of April 1895.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.