Year: 1896

page_text: paratus.
I, CARL KELLNER, of 29, Wasagasse, Vienna, IX, Austria, Doctor of Philosophy, do
hereby declare the nature of this invention to be as follows:-
As has been proved by recent research, many electrolytic phenomena are considerably
influenced by the current-density employed so that some processes appear to be
impossible of execution in an economical manner with the means heretofore available,
on account of the high potential necessary for obtaining the proper current strength
or density.
Electrolytic processes of this kind cannot be carried out at all with the ordinary
plate-shaped electrodes, because the current-density that with normal bath-potential,
can be obtained with plates, is not great enough, and is also not capable of being
easily adjusted or controlled. Furthermore, in many cases where the maximum
current-density that can be obtained with plates is sufficient for the process to be
effected, operations on a commercial scale would necessitate such large amounts of the
costly electrode material (platinum) as alone to render impossible the practical use of
such apparatus.
Now, I have discovered by numerous experiments that the current-density can be
very easily increased and also very simply regulated for practical purposes by employing
the electrode-material in the form of points or edges, instead of as heretofore, in the
form of surfaces. It is essential according to this invention, that these points or
edges be arranged at such a distance from one another that the lines of force issuing
from the several points or edges of one electrode, when projected upon the imaginary
plane passing through the next or adjacent electrode, do not fall into one another, but lie
side by side, so that in addition to the peculiar electrochemical action of such point.
or edge electrodes, there is also produced thereby the novel and technically important
result, that, as compared with the plate-shaped electrodes heretofore employed, a
relatively much smaller amount of electrode-material (platinum) is enabled to convey
the same quantity of current to the electrolytic hath. At the same time certain
disturbing secondary processes such as, for instance, reductions by nascent hydrogen
-are diminished in proportion to the increase in the current-density.
The following example may be given in order to explain what has just been said:-
To a copper wire there are fixed eight platinum wires each 0.1 m/m in diameter,
in such a manner that they lie parallel to one another and form a sort of brush. The
copper wire is connected to the positive pole of a source of electricity and is placed
vertically over a layer of mercury, which constitutes the negative pole and is limited
accurately by a surrounding tube to a superficial area of 0.75 sq. cm. The potential
is 5.35 volts, and is maintained constant during the entire experiment. A saturated
solution of common salt of 18° C. is employed as the electrolyte. According to the
results of experiments the current-strength

page_text: The use of a platinum plate of 2 sq. cm. resulted in a current-strength of 0.4 ampere.
From this it will be seen that the current-density for one single wire 0.1 m/m in
diameter is 5.8 times as great as on an equal part of the surface of the plate when the
wire is placed so far from the other wires that the lines of force issuing from it do not
fall within the range of the lines of force of the adjacent wires.
It is also clear that two wires, when placed at such a distance from each other that
each wire can irradiate an area of 0.75 sq. cm. will give a larger output than a
platinum plate whose weight is one hundred times the weight of the two wires.
It is thus proved, that this kind of electrode effects a new technical result by
enabling the same amount of current to be conveyed to the same baths by means of
a quantity of platinam which is incomparably smaller than has heretofore been
possible.
What has been said above with respect to points, holds good also with regard to
edges. The latter can be provided by arranging sheets of platinum or platinum
foil with their narrow edges towards the nearest electrode to be irradiated or by
arranging wires side by side at intervals, when the radiating elges will run parallel
to the longitudinal axis of these wires.
Now this invention particularly relates to electrodes in which the radiation is
effected through the edges of wires arranged parallelly side by side and at intervals,
corresponding to the aforesaid requirements.
In one arrangement of electrode of this kind, the wire is formed into a network or
a twisted, interlacing, or woven fabric, carried by a dielectric substance or support
and which, in accordance with the distance between consecutive electrodes, will have
a mesh width of from about 3 to 8 mm.
An electrode thus made of wire network or woven fabrics may be constructed by
placing two platinum networks on the sides of a plate of dielectric substance and
electrically connecting the networks together by means of a copper pin or bolt or
several of such pins or bolts may be used passing tightly through a hole in the plate;
or the platinum wire can be drawn through the plate, which is then provided with
suitable holes, in the form of rows of stitches, so that on both sides of the plate there
will be numerous uncovered pieces of wire electrically connected together by the
portions of wire passing through the holes. The holes of the plate must of course, in
order to prevent the electrolyte from passing from compartment to compartment, be
filled up with a material not injuriously affected by the substances present during the
electrolysis.
In another construction the electrode consists of a dielectric substance-e.g. glass,
porcelain, ebonite, or celluloid,-which is made, by way of example, in the form of a
plate & around which a long platinum-wire is wound several times so that the
several turns are say from 3 to 5 mm apart according to the distance from it of the
electrode that is nearest it and is to be irradiated. When the electrode serves at
the same time for conveying current direct from an electric generator, the ends of the
wires wound around the dielectric substance, or the several turns of wire, are connected
by means of a copper wire, which is provided with a clamp and is covered with
platinum and which can be arranged in the middle of the plate or laterally at one of
its edges.
My improved electrodes do not net merely as a solid platinum plate, so that by
their employment considerable economy in this expensive metal is effected but they
also enable a new technical effect to be produced in that the surfaces of the wires
work with an extraordinarily great current-density (with from 10 to 15 times the
current-density of a plate) and in consequence of this render possible the carrying
out of processes that cannot be perforined with any of the electrodes heretofore known
It is preferable and also simplest and best as regards the conduction of
current, that such electrodes he used in circuit in a bipolar manner.
For the purpose of practically employing such electrodes in an electrolytic
apparatus, the plate carrying the network or around which the wire is laid in turns
arranged at a suitable distance apart is inserted into the grooves of strips or side
pieces of glass, porcelain, gutta-percha, caoutchouc, celluloid, or the like, which, on

page_text: the one hand, keep the distance between two electrodes definite and constant and, on
the other hand, keep the part of the electrolyte situate between two electrodes
separate from that between two other such electrodes and thereby prevent loss of
current through short-circuiting.
In one arrangement of electrolytic apparatus with such double-pole or bi-polar
electrodes the side portions of the electrodes, which are arranged parallel and side by
side, are held firmly together by means of ebonite bolts which pass through
corresponding holes in the side portions of the said electrodes and through cross
pieces placed against the end electrodes.
The electrode-block produced in this way is placed in a vessel which is provided in
the bottom with an inlet-pipe for the electrolyte and laterally with gutters and
outlet-pipes. The end plates are connected by means of clamps with the conducting
wires of an electric generator. The entering electrolyte rises between the electrode-
plates in layers that are separated from one another, is electrolized by the uncovered
lengths of wire, and flows in separate streams over the strips or side pieces in which
the electrodes are placed and which for this purpose, at one side of the electrode
plates, are made shorter than the said plates and gutter-shaped at the top. The
electrolyte flowing over the said strips or side pieces passes into the gutters of the
vessel from which it runs away through the outlet pipes.
I am aware that wires and networks of platinum have been proposed as electrodes ;
but such electrodes have nothing in common with the electrodes hereinbefore
described because, in consequence of the small conducting capacity of thin wires,
which were proposed-merely for the purpose of distributing the current and there-
fore for quite different reasons from those on which electrodes according to this
invention are based it is not possible to obtain the high current-density that is
necessary for producing the new effect hereinbefore mentioned.
For the Applicant
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.
I, CARL KELLNER, of 29, Wasagasse, Vienna, IX, Austria, Doctor of Philosophy, 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:-
As has been proved by recent research, many electrolytic phenomena are consider-
ably influenced by the current density employed, so that some processes appear to be
impossible of execution in an economical manner, with the means heretofore available,
on account of the bigh potential necessary for obtaining the proper current density.
Electrolytic processes of this kind cannot be carried out at all with the ordinary plate-
shaped electrodes, because the current-density that, with normal bath-potential, can
be obtained with plates, is not great enough, and is also not capable of being easily
adjusted or controlled. Furthermore, in inany cases where the maximum current-
density that can be obtained with plates is sufficient for the process to be effected,
operations on a commercial scale would necessitate such large amounts of the costly
electrode material (platinum) as alone to render impossible the practical use of such
apparatus.
Now, I have discovered by numerous experiments that the current-density can be

page_text: very easily increased, and also very simply regulated for practical purposes, by
employing the electrode-material in the form of points or edges, instead of as hereto-
fore, in the form of surfaces. It is essential, according to this invention, that these
points or edges be arranged at such a distance from one another that the lines of
foree issuing from the several points or edges of one electrode, when projected upon
an imaginary plane passing through the next or adjacent electrode, will not fall into
one another, but will lie side by side, so that in addition to the peculiar electro-
chemical action of such point or edge electrodes, there will also be produced thereby
the novel and technically important result, that, as compared with the plate-shaped
electrodes heretofore employed, a much smaller amount of electrode-material
(platinum) will be enabled to convey the same quantity of current to the electrolytic
batb. At the same time certain disturbing secondary processes-such as, for
instance, reductions by nascent hydrogen-are diminished in proportion to the
increase in the current-density.
Now this invention particularly relates to electrodes in which the radiation is
effected through the edges of wires arranged parallelly side by side and at intervals
corresponding to the aforesaid requirements.
In one arrangement of electrode of this kind, the wire is formed into a network or
a twisted, interlacing, or woven fabric, which is carried by a dielectric substance or
support and which, in accordance with the distance between consecutive electrodes,
has a mesh-width of from about 3 to 8 min.
An electrode thus made of wire network or woven fabrics may be constructed, as
illustrated by the accompanying cross-section Fig. 1 and isometrical view Fig. 2, by
placing two platinum networks a on the opposite sides of a plate of dielectric
substance and electrically connecting the networks a together by means of a copper
pin or bolt al (or several of such pins or bolts may be used) passing tightly through
a hole in the plate b. Instead of making the platinum wire into networks, it may
be drawn through the plate & (which will then be provided with suitable holes) in the
form of rows of stitches, so that on both sides of the plate there will be numerous
uncovered pieces of wire electrically connected together by the portions of wire
passing through the holes. The holes of the plate must, of course, in order to prevent
the electrolyte from passing from compartment to compartment, be filled up with a
material not injuriously affected by the substances present during the electrolysis,
In another construction the electrode consists of a dielectric substance-e.g., glass,
porcelain, ebonite, or celluloid-which is made, by way of example, in the form of a
plate and around which a long platinum wire is wound several times so that the
several turns are say from 3 to 5 mm. apart according to the distance from it of the
electrode that is nearest it and is to be irradiated. When the electrode serves at
the saine time for conveying current direct from an electric generator, the ends of the
wires wound around the dielectric substance, or the several turns of wire, are
connected by means of a copper wire, which is provided with a clamp and is covered
with platinum and which can he arranged in the middle of the plate or laterally at
one of its edges.
My improved electrodes do not act merely as a solid platinum plate, so that by
their employment considerable economy in this expensive metal is effected, but they
also enable a new technical effect to be produced in that the surfaces of the wires
work with an extraordinarily great current-density (with from 10 to 15 times the
current-density of a plate) and in consequence of this render possible the carrying
out of processes that cannot be performed with any of the electrodes heretofore known
to me. It is preferable and also simplest and best as regards the conduction of
current, that such electrodes be used in circuit in a bi-polar manner.
For the purpose of practically employing such electrodes in an electrolytic
apparatus, the plate that carries the network, or around which the wire is laid in
turns arranged at a suitable distance apart, is inserted into the grooves of strips or
side pieces of glass, porcelain, gutta-percha, caoutchouc, celluloid, or the like, which,
on the one hand, keep the distance between two electrodes definite and constant and,
on the other hand, keep the part of the electrolyte situate between two electrodes

page_text: separate from that between each of the electrodes and an adjacent electrode and
thereby prevent loss of current through short-circuiting.
In me arrangement of electrolytic apparatus with such bi-polar electrodes, the
aforesaid side pieces of the electrodes, which are arranged parallel and side by side.
are held firmly together by means of ebonite bolts, which pass through corresponding
holes in the said side pieces and through cross pieces placed against the end
electrodes.
The electrode-block produced in this way is placed in a vessel which is provided in
the bottom with an inlet pipe for the electrolyte and latterly with gutters and outlet-
pipes. The end plates are connected by means of clamps with the conducting wires
of an electric generator. The entering electrolyte rises between the electrode-plates
in layers that are separated from one another, is electrolized by the uncovered lengths
of wire, and flows in separate streams over the strips or side pieces in which the
electrodes are placed and which for this purpose, at one side of the electrode plates,
are inade shorter than the said plates and gutter-shaped at the top. The electrolyte
Howing over the said strips or side pieces passes into the gutters of the vessel from
which it runs away through the outlet-pipes.
I am aware that wires and networks of platinum have been proposed as electrodes;
but such electrodes have nothing in common with the electrodes hereinbefore
described because, in consequence of the small conductive capacity of thin wires,
which were proposed-merely for the purpose of distributing the current and there-
fore for reasons quite different from those on which electrodes according to this
invention are based,-it is not possible to obtain the high current-density that is
necessary for producing the new effect hereinbefore mentioned.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed I declare that what I claim is:-
1. An electrode for producing high current-densities, consisting of platinum-wires
secured to a support of dielectric material at such distances apart that the lines of
force radiating from each wire upon the nearest electrode will fall outside the range
of the lines of force of the neighbouring wires.
2. An electrode of the kind referred to in the preceding claim, in which the
wires are laid around a plate of dielectric material in straight windings or in network-
form.
3. An electrode of the kind referred to in claim
arranged in the form of nets on both sides of a plate
are brought into conductive connection with each
substantially as described and shown.
1, in which the wires are
of dielectric material and
other through the plate,
4. In combination with an electrode of the kind referred to in claim 1, grooved
strips of dielectric material, between which the supports are held and which prevent
the liquid passing between two such electrodes from forming short-circuits,
substantially as described.
5. The combination of a block formed by securing together electrodes of the kind
referred to in claim 1, and strips of the kind referred to in claim 4, with a vessel into
which the said block is inserted and which is provided with a central inlet-opening
for the electrolyte and with lateral gutters for the electrolized liquid, so that the
electrolyte is compelled to rise up in separate layers between the electrodes and after
the electrolysis to flow over and down along the strips in separate streams,
substantially as described.
Dated this 17th day of April 1897.