Improvements in Electrolytical Decomposing Apparatus.
Year: 1894

page_text: Date of Application, 8th Feb., 1894
Complete Specification Left, 5th Dec., 1891-Accepted, 12th Jan., 1895
PROVISIONAL SPECIFICATION.
Improvements in Electrolytical Decomposing Apparatus.
1, CARL KELLNER, of Wasagasse 29, Vienna I, Austria, Doctor of Philosophy,
do hereby declare the nature of this invention to be as follows:-
Practical experience with carbon electrodes has shown that such electrodes are
liable to comparatively rapid wear. To obviate this drawback, I have found. it
advantageous to surround one or both electrodes. with finely powdered carbon, as
described in the Specification of Letters Patent granted to me No. 9346 of- 1892.
It has however been found that the construction of electrolytical apparatus with
vertical electrodes and the tight-jointing thereof renders such apparatus expensive
and complicated; and the small bubbles of gas liberated at the electrode are
prevented from rising freely by the vertically arranged layers of finely powdered
carbon.
Now this invention has for object to obviate these difficulties. For this purpose
I arrange the electrode or electrodes at the bottom of the electrolytical vessel.
According to one construction of apparatus according to this invention, I arrange
the said electrode or electrodes horizontally or approximately so and side by side
so that it or they constitute the bottom of the electrolytical vessel. To enable the
electrode or electrodes to be thus fixed in place, I prefer to pour into the vessel
that is to form the electrolytical cell, a suitable non-conducting material such as
asphalte, paraffin, or ozokerite in a molten or liquid condition, and into the mass of
this material, whilst the same is still soft, I embed the electrodes, insulating spaces
being left between adjacent portions of the electrodes. Into each of these spaces
may be inserted if necessary a plate or partition of porous or non-porous
conducting material.
The upper surface of the electrodes which are subject to more or less wear
according to the nature of the substance to be electrolytically decomposed, is
preferably covered alternately with finely and coarsely powdered carbon compressed.
firmly in place.
If the electrolyte be passed from the negative side through the box the bottom
of which is covered with electrodes arranged as above described, the apparatus may,
even as it is, be employed for certain purposes, in particular for the manufacture of
bleaching liquor, and especially in cases where the chlorine liberated at the anodè,
as in the decomposition of sodic chloride, is compelled by means of an inclined
plate of glass to become dissolved in the sodic hydrate formed at the cathode.
Where it is desired to collect the gas liberated at one electrode, I arrange above
the said electrode a gas box which forms when immersed into the liquid a
hydraulic seal.
'
In cases where the final products of electrolysis show a strong tendency to
recombine with each other, the edge of the gas box may be arranged to extend
down below one or more partitions, the spaces between which and the gas box are
preferably filled with a substance that will prevent, or at least render difficult, the
diffusion of the liquids contained in the electrode spaces.
The aforesaid partition or partitions, may, when porous, be carried up to a
height above the level of the electrolyte.
As the generation of the heat which takes place in consequence of certain
secondary reactions has often an injurious effect on the smooth working of the

page_text: electrolytical operation, that electrode at the surface which the said secondary
reaction takes place, as for instance the cathode when decomposing a solution of
sodic-chloride, may be made hollow, so that a cooling medium may be caused to
circulate inside the said electrode during the process.
As is well known, the large number of the electrical connections usually required
and the labour necessary to keep them clean, constitute two of the greatest dis-
advantages to the use of electrolysis on a commercial scale. To obviate these
disadvantages I construct the herein before described electrolytical apparatus, in all
cases where the operation to be effected will permit, in such a manner that contacts
or connections required for connecting the first and last electrodes to the source of
the electric current, whilst the intermediate electrodes are compelled, by means of
non-porous partitions placed on or partly in their upper surfaces to each act as
negative and positive electrodes respectively at opposite sides of the partition
arranged upon it. This arrangement, besides dispensing with a large number of
contacts, has the further advantage of not necessitating the use of large electrode
plates as heretofore, because the bottom of the aforesaid box can be filled in with
small pieces of electrode plates.
Bi-polar electrodes arranged as described may if desired be made of two kinds of
substances, and also be provided with a cooling device. Thus in one arrangement
the electrodes or parts thereof are provided at their upper surfaces with a layer of
mercury or sheet of platinum. In another arrangement a flat tube of conducting
material in which a cooling medium can be caused to circulate, is placed upon that
part of each bi-polar electrode that would otherwise be liable to become heated.
The gas chambers when two or more are used, are perforated or recessed at
one side to permit of the passage of the electric current from one electrode space to
the next, a partition being arranged at the outer side and in some cases at each
side of such perforated or recessed parts, when necessary, and the intervening
space or spaces charged with filling material to prevent diffusion of the electrolyte.
Dated this 8th day of February 1894.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.
Improvements in Electrolytical Decomposing Apparatus.
I, CARL KELLNER, of Wasagasse 29, 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 :-
Practical experience with carbon electrodes in electrolytic work has shown that
such electrodes are liable to comparatively rapid wear, and in order to obviate this
draw-back one or both of the electrodes have been surrounded with finely powdered
carbon. In electrolytical apparatus with vertical electrodes this arrangement
entails, however, the disadvantages that the construction of such apparatus, and
the tight-jointing of the electrodes with the material in which they are imbedded,
are rendered expensive and complicated.
The object of the present invention is to obviate these objections, and this
object is attained by an arrangement in which, in contradistinction to all other
electrolytical apparatus hitherto proposed and known to me, the electrodes are
placed at the bottom of the electrolytical cell and are separated from one another
by special devices adapted to diminish diffusion, the said electrodes when necessary,
being placed in series oue behind another by means of partitions placed upon or

page_text: in them. By this means substantial advantages are obtained over all apparatus
hitherto proposed, so far as I am aware, for similar purposes.
The accompanying drawings, are vertical sections of various arrangements of
electrolytical apparatus according to this invention.
As will be seen, the electrodes in each arrangement are arranged in such a
manner as to form the bottom or part of the bottom of the electrolytic vessel and
to lie side by side in a horizontal or approximately horizontal position. To enable
the electrodes to be fixed in this position, there is poured in a melted condition
into the vessel that is to form the electrolytic cell a suitable non-conducting
material, e.g. asphalt, paraffine, or ozokerite; and into the mass of this material,
whilst the same is still soft, the electrodes are embedded. Between each two of
the electrodes there is left a space which acts as an insulating layer and into which
there may, if necessary, be inserted a plate or partition of porous or of non-porous
non-conducting material. Those surfaces of the electrodes which, from the nature
of the process to be carried out, are subject to the greatest wear, is preferably
covered with a layer composed of finely powdered and coarsely powdered carbon
compressed firmly in place.
In Fig. 1, which shows a cross-section through the bottom of an electrolytic
vessel constructed in this manner, A & B are the electrodes embedded in the non-
conducting material C and separated by a partition D. E is a firm foundation
constituting the bottom of the vessel on which the non-conducting material C is
poured, and F is powdered carbon stamped down on one of the electrodes, for
example the positive one.
5.
...If, now, the electrolyte be passed from the negative side through the electrolytic
vessel the bottom of which is provided with electrodes as described, this apparatus
can, even as it is, be employed for certain purposes, in particular for the manufac-
ture of bleaching-liquor, and especially if, taking for an example the decomposition
of sódic chloride, the chlorine liberated at the anode A, he compelled by means of
an inclined plate of glass G to become dissolved in the sodic hydrate formed at the
cathode.
If, however, it be desired to collect the gas liberated at one of the electrodes,
there is arranged over the electrode in question a gas bell or gas box G', which,
when immersed in the liquid, forms a hydraulic seal, as shown in Fig. 2. In cases
where the final products of the electrolysis exhibit a strong tendency to recombine
with each other, the edge of the gas bell or gas box G¹ may be arranged to extend
down behind one or between two partitions D as shown in Figs. 3 & 4 respectively,
the space or spaces between the partition or partitions and the box-wall being
preferably filled with packing-material H, which will prevent, or at least render
difficult, the diffusion of the liquids contained in the electrode-spaces. The
partitions D, when porous, may be carried up to a height above the level of the
electrolyte, as shown in Fig. 5.
As is well known, the large number of the metallic electrical contacts or connec-
tions usually required, and their maintenance in a clean condition, constitute two of
the chief disadvantages of the use of electrolysis on a commercial scale. To
obviate these disadvantages, electrolytical apparatus of the kind hereinbefore
described are, in all cases, in which the process to be carried out will permit,
arranged in such a manner that metallic contacts or connections are required for
connecting the first-and last electrodes only with the source of the electric current,
whilst each of the intermediate electrodes is compelled, by means of a non-porous
and non-conducting partition placed in it or upon its upper surface, to act as a
negative and a positive electrode at opposite sides of the said partition.
This arrangement, besides dispensing with a large number of contacts, has the
further advantage of not necessitating the use, as heretofore, of large electrode-
plates, because the bottom of the box or electrolytic vessel can simply be paved
with small electrode-plates.
Fig. 6 shows an arrangement of this kind. Aº, A, B, A¹ are the electrodes,
which are formed in this case of carbon-plates and into which are cemented the

page_text: non-porous and non-conducting partitions G2 that extend up beyond the level of
the electrolyte. The current, entering at Aº, is compelled by the partition D
between the electrodes A & A to flow through the electrolyte in the direction
indicated by the arrow a. Now since the partition G2, extending up above the
level of the electrolyte, separates the portion of the electrolyte containing the arrow a
from the remainder of the electrolyte, the current is compelled to pass onward through
the substance of the electrode itself, and is again compelled by the fresh hindrance
to its course presented by the partition D (between the electrodes A & B), to flow
through the electrolyte in the direction of the arrow in order to reach the
electrode B. As this proceeding is repeated at every partition G2, it. is obvious
that each electrode carrying a partition G2 is rendered bi-polar by the employment
of such partition, i.e. it acts negatively at the part where the current enters it,
and positively at the part where the current passes out of it.
The electrodes need not be embedded in the non-conducting material C up to
their upper surface, thereby preventing the employment of their lateral surfaces;
they may be only partially embedded in such material so as to allow the said lateral
surfaces to come into operation. The electrodes may also be chamfered at one
side, as shown in Fig. 7.
Bi-polar electrodes of this kind may, if desired, be made of two different
materials at opposite sides of the partitions G. Fig. 8 shows, by way of example,
an arrangement in which one half of the bi-polar electrode A is provided with a
layer I of mercury or of platinum.
In the bi-polar arrangement, the gas-chambers G' are, when two or more are
used, made with only one solid and non-conducting side, i.e. the wall of the same
is cemented at one side in the electrode and at the other side is perforated or
recessed or otherwise adapted to allow the current to pass therethrough and flow
away over the partition D and through the electrolyte an example of such an
arrangement is shown in Fig. 9.
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. Electrolytical apparatus in which the positive and negative electrodes are
arranged to constitute the bottom or part of the bottom of the electrolytical
vessel and are separated from each other by a porous or non-porous partition or
partitions D, which, when non-porous, terminate below the level of the electrolyte,
substantially as set forth.
2. Electrolytical apparatus of the kind specified in-the preceding claim, in which
only the first and last electrodes are adapted to be connected with an electric
generator whilst the intermediate electrodes are arranged in series, so as to be
bi-polar, by means of partitions G2 or gas-chambers G₁ which are placed in or on
the surface of the electrodes and project above the level of the electrolyte,
substantially as described.
3. Apparatus of the kind specified in Claim 2, in which parts of the bi-polar
electrodes on opposite sides of the gas-chambers or partitions are composed of two
different materials as set forth.
4. Electrolytical apparatus constructed and arranged substantially as herein-
before described with reference to the several examples shown in the accompanying
drawings.